| 1. |
- Bernes, Gun
(författare)
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Bioavailability of α-tocopherol stereoisomers in plasma and tissues of lambs fed different proportions of all-rac- α-tocopheryl acetate and RRR- α-tocopheryl acetate
- 2019
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 97, s. 1222-1233
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Tidskriftsartikel (refereegranskat)abstract
- A ratio of 1.36:1 in relative bioactivity of RRR-alpha-tocopheryl acetate as a natural (Nat-alpha-T) source to all-rac-alpha-tocopheryl-acetate, as a synthetic (Syn-alpha-T) source, is generally accepted. This factor also largely reflects the difference in bioavailability. However, studies indicate that neither bioavailability of alpha-tocopherol stereoisomers nor relative bioavailability between them are constant, but are dose-dependent and differ between organs. However, no information is available about how different ratios between synthetic and natural alpha-tocopherol affect bioavailability of alpha-tocopherol stereoisomers. Thirty lambs were randomly assigned to diets supplied with additives containing 5 different Syn-alpha-T to Nat-alpha-T ratios, including 100: 0, 75: 25, 50: 50, 25: 75, and 0:100. The experiment lasted for 70 d after which the lambs were slaughtered. The amount of RRR-alpha-tocopherol generally increased in plasma and organs with increasing the proportion of Nat-alpha-T in the diet (P < 0.05). However, the relative bioavailability of RRR- and RRS-alpha-tocopherol in plasma, organs, and abdominal fat generally decreased with increasing the proportion of Nat-alpha-T in the diet (P < 0.05), whereas the other stereoisomers only showed minor changes with the exception of liver. However, a linear response was maintained between the ratio of stereoisomers in the feed and the ratio in plasma and organs. In conclusion, regardless of Syn-alpha-T to Nat-alpha-T ratio in the diets, amounts of alpha-tocopherol stereoisomers in plasma, brain, heart, lungs, and abdominal fat were in the following order: RRR > RRS, RSR, RSS > Sigma 2S.
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| 2. |
- Connysson, Malin, et al.
(författare)
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Road transport and diet affect metabolic response to exercise in horses
- 2017
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 95, s. 4869-4879
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effects of transport and diet on metabolic response during a subsequent race-like test in Standardbred horses in training fed a forage-only diet and a 50: 50 forage: oats diet. Six trained and raced Standardbred trotter mares were used. Two diets, 1 forage-only diet (FONLY) and 1 diet with 50% of DM intake from forage and 50% from oats (FOATS), were fed for two 29-d periods in a crossover design. At Day 21, the horses were subjected to transport for 100 km before and after they performed an exercise test (transport test [TT]). At Day 26, the horses performed a control test (CT), in which they were kept in their stall before and after the exercise test. Blood samples were collected throughout the study, and heart rate and water intake were recorded. Heart rate and plasma cortisol, glucose, and NEFA concentrations were greater for the TT than for the CT (P = 0.008, P = 0.020, P = 0.010, and P = 0.0002, respectively) but were not affected by diet. Plasma acetate concentration was lower during the TT than during the CT (P = 0.034) and greater for the FONLY than for the FOATS (P = 0.003). There were no overall effects of the TT compared with the CT on total plasma protein concentration (TPP), but TPP was lower with the FONLY than with the FOATS (P = 0.016). There was no overall effect of the TT compared with the CT on water intake, but water intake was greater with the FONLY than the FOATS (P = 0.011). There were no overall effects of transport or diet on BW, plasma lactate, or plasma urea concentration. It was concluded that both transport and diet affect metabolic response during exercise in horses. Aerobic energy supply was most likely elevated by transportation and by the FONLY. The FONLY also decreased exercise-induced effects on extracellular fluid regulation. These results highlight the importance of experimental design in nutrition studies. If the aim is to examine how a diet affects exercise response in competition horses, transport should preferably be included in the experimental design, because horses are likely to be transported before a competition.
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| 3. |
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| 4. |
- Hartmann, Elke, et al.
(författare)
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A Nordic survey of management practices and owners' attitudes towards keeping horses in groups
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 4564-4574
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Tidskriftsartikel (refereegranskat)abstract
- Keeping horses in groups is widely recommended but limited information is available about how this is implemented in practice. The aim of this survey was to describe how horses are kept in the Nordic countries in relation to sex, age, breed, and equestrian discipline and to assess owners' attitudes toward keeping horses in groups. Horse owners in Denmark, Finland, Norway, and Sweden were approached using a web-based questionnaire, which was translated into 4 languages and distributed online via equestrian forums, organizations, and social media. The number of respondents was 3,229, taking care of 17,248 horses. Only 8% of horses were never kept in groups, 47% were permanently grouped for 24 h/d, and 45% were stabled singly but grouped during turnout. Yearlings were most often permanently kept in groups (75%), mares and geldings more commonly during parts of the day (50 and 51%, respectively), and stallions were often kept alone (38%). Icelandic horses were more likely to be permanently kept in groups (36%) than warmbloods (16%) and ponies (15%). Twice as many competition horses (51%) were never grouped compared with horses used for breeding (20%) or leisure purposes (15%). The majority of respondents (86%) strongly agreed that group housing benefits horse welfare and that it is important for horses to have the company of conspecifics (92%). Nevertheless, not all horses were kept in groups, showing that attitudes toward group housing may not necessarily reflect current management. The risk of injury was a concern of many respondents (45%), as was introducing unfamiliar horses into already established groups (40%) and challenges in relation to feeding in groups (44%). Safety of people (23%) and difficulties handling groupkept horses (19%) were regarded as less problematic. Results suggest that the majority of horses have the possibility to freely interact with other horses, either as fulltime members of a group during 24 h/d or during turnout. Future research should address the extent to which being a part-time member of a group affects horse welfare. For permanent group housing to become more widespread, such as it is the case for most farm animals, future research could focus on solving some of the reoccurring problems perceived with keeping horses in groups. The dissemination of evidence-based information on all aspects around keeping horses in groups can ultimately stimulate further positive changes in the management of group-kept horses.
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| 5. |
- Hartmann, Elke, et al.
(författare)
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Daytime shelter use of individually kept horses during Swedish summer
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 802-810
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden, no provision for summer shelter to protect horses from heat and insects is required, although access to shelter for horses kept outdoors 24 h during winter is a requirement. This study investigated horses' daytime shelter-seeking behavior in relation to weather conditions and insect activity during a 2-wk period in summer. Eight Warmblood riding horses had access to 2 shelters of different design to test which shelter design is preferred by horses. Furthermore, rectal and skin temperatures and insect-defensive behavior were measured to test whether horses would benefit from the provision of shade. The horses were kept alone in paddocks for 4 d. During 2 d, horses had access to 2 shelters: 1) open shelter with roof and uncovered sides and 2) closed shelter with roof, wind nets on 2 sides, and opaque plastic opposite the entrance. Weather conditions (ambient temperature, relative humidity, solar radiation, wind speed) were recorded every 10 min. The number of insects (flies, mosquitos) was counted from insect traps placed in each shelter and outside. Behavior (shelter use, insect-defensive behavior, locomotion, grazing) was recorded at 5-min intervals between 0900 to 1200 h and 1300 to 1600 h and rectal and skin temperatures were measured at 0800 h, 1200 h, and 1600 h. Data were analyzed with PROC MIXED and GLIMMIX procedure for Generalized Linear Mixed Models. Ambient temperature ranged from 16 to 25 degrees C (average temperature humidity index 65.7 +/- 1.4). Five horses preferred the closed shelter and were observed inside up to 2.5 h continuously. Greater wind speed decreased the likelihood of observing horses inside the shelter (P < 0.001), as did lower numbers of flies (P < 0.001). The insect-defensive behaviors, skin shiver and ear flick, were performed less frequently when horses were using the closed shelter (P < 0.001), indicating that they were less disturbed by insects. Thirty-minute shelter use had no effect on rectal and skin temperatures (P > 0.05). Results showed that horses made use of shelters during the summer even when weather conditions were moderate. A shelter with roof and covers on 3 sides was preferred over a shelter with roof only and can reduce insect-defensive behavior.
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| 6. |
- Hartmann, Elke, et al.
(författare)
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Management of horses with focus on blanketing and clipping practices reported by members of the Swedish and Norwegian equestrian community
- 2017
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 95, s. 1104-1117
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Tidskriftsartikel (refereegranskat)abstract
- Limited information is available on the extent to which blankets are used on horses and the owners' reasoning behind clipping the horse's coat. Research on the effects of those practices on horse welfare is scarce but results indicate that blanketing and clipping may not be necessary from the horse's perspective and can interfere with the horse's thermoregulatory capacities. Therefore, this survey collected robust, quantitative data on the housing routines and management of horses with focus on blanketing and clipping practices as reported by members of the Swedish and Norwegian equestrian community. Horse owners were approached via an online survey, which was distributed to equestrian organizations and social media. Data from 4,122 Swedish and 2,075 Norwegian respondents were collected, of which 91 and 84% of respondents, respectively, reported using blankets on horses during turnout. Almost all respondents owning warmblood riding horses used blankets outdoors (97% in Sweden and 96% in Norway) whereas owners with Icelandic horses and coldblood riding horses used blankets significantly less (P < 0.05). Blankets were mainly used during rainy, cold, or windy weather conditions and in ambient temperatures of 10 degrees C and below. The horse's coat was clipped by 67% of respondents in Sweden and 35% of Norwegian respondents whereby owners with warmblood horses and horses primarily used for dressage and competition reported clipping the coat most frequently. In contrast to scientific results indicating that recovery time after exercise increases with blankets and that clipped horses have a greater heat loss capacity, only around 50% of respondents agreed to these statements. This indicates that evidence-based information on all aspects of blanketing and clipping has not yet been widely distributed in practice. More research is encouraged, specifically looking at the effect of blankets on sweaty horses being turned out after intense physical exercise and the effect of blankets on social interactions such as mutual grooming. Future efforts should be tailored to disseminate knowledge more efficiently, which can ultimately stimulate thoughtful decision-making by horse owners concerning the use of blankets and clipping the horse's coat.
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| 7. |
- Hidalgo, André
(författare)
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Accuracy of genome-enabled prediction exploring purebred and crossbred pig populations
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 4684-4691
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Tidskriftsartikel (refereegranskat)abstract
- Pig breeding companies keep relatively small populations of pure sire and dam lines that are selected to improve the performance of crossbred animals. This design of the pig breeding industry presents challenges to the implementation of genomic selection, which requires large data sets to obtain highly accurate genomic breeding values. The objective of this study was to evaluate the impact of different reference sets (across population and multipopulation) on the accuracy of genomic breeding values in 3 purebred pig populations and to assess the potential of using crossbreed performance in genomic prediction. Data consisted of phenotypes and genotypes on animals from 3 purebred populations (sire line [SL] 1, n = 1,146; SL2, n = 682; and SL3, n = 1,264) and 3 crossbred pig populations (Terminal cross [TER] 1, n = 183; TER2, n = 106; and TER3, n = 177). Animals were genotyped using the Illumina Porcine SNP60 Beadchip. For each purebred population, within-, across-, and multipopulation predictions were considered. In addition, data from the paternal purebred populations were used as a reference set to predict the performance of crossbred animals. Backfat thickness phenotypes were precorrected for fixed effects and subsequently included in the genomic BLUP model. A genomic relationship matrix that accounted for the differences in allele frequencies between lines was implemented. Accuracies of genomic EBV obtained within the 3 different sire lines varied considerably. For within-population prediction, SL1 showed higher values (0.80) than SL2 (0.61) and SL3 (0.67). Multipopulation predictions had accuracies similar to within-population accuracies for the validation in SL1. For SL2 and SL3, the accuracies of multipopulation prediction were similar to the within-population prediction when the reference set was composed by 900 animals (600 of the target line plus 300 of another line). For across-population predictions, the accuracy was mostly close to zero. The accuracies of predicting crossbreed performance were similar for the 3 different crossbred populations (ranging from 0.25 to 0.29). In summary, the differences in accuracy of the within-population scenarios may be due to line divergences in heritability and genetic architecture of the trait. Within- and multipopulation predictions yield similar accuracies. Across-population prediction accuracy was negligible. The moderate accuracy of prediction of crossbreed performance appears to be a result of the relationship between the crossbreed and its parental lines.
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| 8. |
- Hidalgo, André, et al.
(författare)
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Accuracy of genomic prediction using deregressed breeding values estimated from purebred and crossbred offspring phenotypes in pigs
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 3313-3321
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Tidskriftsartikel (refereegranskat)abstract
- Genomic selection is applied to dairy cattle breeding to improve the genetic progress of purebred (PB) animals, whereas in pigs and poultry the target is a crossbred (CB) animal for which a different strategy appears to be needed. The source of information used to estimate the breeding values, i.e., using phenotypes of CB or PB animals, may affect the accuracy of prediction. The objective of our study was to assess the direct genomic value (DGV) accuracy of CB and PB pigs using different sources of phenotypic information. Data used were from 3 populations: 2,078 Dutch Landrace-based, 2,301 Large White-based, and 497 crossbreds from an F1 cross between the 2 lines. Two female reproduction traits were analyzed: gestation length (GLE) and total number of piglets born (TNB). Phenotypes used in the analyses originated from offspring of genotyped individuals. Phenotypes collected on CB and PB animals were analyzed as separate traits using a single-trait model. Breeding values were estimated separately for each trait in a pedigree BLUP analysis and subsequently deregressed. Deregressed EBV for each trait originating from different sources (CB or PB offspring) were used to study the accuracy of genomic prediction. Accuracy of prediction was computed as the correlation between DGV and the DEBV of the validation population. Accuracy of prediction within PB populations ranged from 0.43 to 0.62 across GLE and TNB. Accuracies to predict genetic merit of CB animals with one PB population in the training set ranged from 0.12 to 0.28, with the exception of using the CB offspring phenotype of the Dutch Landrace that resulted in an accuracy estimate around 0 for both traits. Accuracies to predict genetic merit of CB animals with both parental PB populations in the training set ranged from 0.17 to 0.30. We conclude that prediction within population and trait had good predictive ability regardless of the trait being the PB or CB performance, whereas using PB population(s) to predict genetic merit of CB animals had zero to moderate predictive ability. We observed that the DGV accuracy of CB animals when training on PB data was greater than or equal to training on CB data. However, when results are corrected for the different levels of reliabilities in the PB and CB training data, we showed that training on CB data does outperform PB data for the prediction of CB genetic merit, indicating that more CB animals should be phenotyped to increase the reliability and, consequently, accuracy of DGV for CB genetic merit.
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| 9. |
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| 10. |
- Ivarsson, Emma, et al.
(författare)
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Whole-grain rye, refined wheat, and whole-grain wheat breads influence metabolic fingerprints differently in pigs
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94, s. 161-163
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare the influence of whole-grain rye bread (WGRB), whole-grain wheat bread (WGWB), and refined wheat bread (WB) on the gut metabolic fingerprint to increase the understanding of the mechanism behind health aspects related to whole-grain products. Five pigs with an initial weight of 46 kg were used in a changeover design, with 3 diets and 3 periods. The experimental diets consisted of WGRB, WGWB, and WB and were balanced with similar content of dietary fiber (adjusted with cellulose), protein, and fat. Each diet period lasted for 7 d. Fecal samples were collected during Days 4 through 7 in each experimental period. Nuclear magnetic resonance (NMR) was used to analyze metabolic profiles from the fecal samples. Principal component analysis of metabolic fingerprints showed that the type of bread influenced the metabolic profile and that WGRB influenced metabolic profiles differently compared with WGWB (P = 0.03) and WB (P = 0.04). Quantification of the shortchain fatty acids in the NMR data revealed differences with higher concentrations of lactate (P = 0.04) and lower molar proportions of acetate (P = 0.03) in rye bread compared with wheat breads.
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| 11. |
- Jardstedt, Mikaela, et al.
(författare)
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Intake and feed utilization in two breeds of pregnant beef cows fed forages with high-fiber concentrations
- 2018
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 96, s. 3398-3411
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Tidskriftsartikel (refereegranskat)abstract
- Hereford and Charolais beef cows (n = 24 per breed) were used to study the effect of breed and to evaluate late-cut reed canarygrass (RC) and whole-crop oats plus urea (WCO) compared with late-cut timothy (TG) with respect to feed intake and digestibility, rumination time, fecal particle size (PS) distribution, N excretion, and ruminal microbial CP production (MCP). The TG and RC were cut at flowering and WCO at hard dough stage of maturity. Cows were group-housed, 6 groups per breed, and fed 3 diets ad libitum in 3 periods. The study was designed as two 3 x 3 Latin squares amalgamated to form a 3 x 6 rectangle for each breed. All data were statistically analyzed on group level. Indigestible NDF (iNDF) and urinary creatinine excretion were used as markers to estimate apparent diet digestibility and daily urine volume, respectively. Fecal PS distribution was determined by dry sieving, and ruminal MCP synthesis was estimated based on urinary output of purine derivatives. The TG diet had a higher apparent digestibility of OM and NDF (P < 0.001) than RC and WCO, which did not differ. The TG diet resulted in the greatest daily DMI, followed by WCO and RC (P < 0.001). Intake of NDF (NDFI, kg/d and % of BW) was greatest for TG, followed by RC and WCO (P < 0.001). Rumination time per kg DMI was longest for RC (P < 0.001), and RC and WCO resulted in longest rumination time per kg NDFI (P < 0.001). The WCO diet resulted in the largest geometric mean fecal PS and proportion of large particles and in the smallest proportion of small particles, whereas the opposite was found for RC, with TG being intermediate (P < 0.001). Intakes in kg per day were higher for Charolais than for Hereford (P = 0.002), but no breed effect was detected when intake was expressed in relation to BW. Charolais ruminated longer per kg NDFI corrected for BW (P = 0.02) and had smaller mean fecal PS (P = 0.049) than Hereford. Total N excretion was highest for RC and lowest for WCO (P < 0.001). The TG diet stimulated MCP production to a greater extent than RC and WCO (P < 0.001). The results indicate that late-cut RC and WCO could be suitable alternatives to late-cut TG for ad libitum feeding of early pregnant beef cows, and that intake was associated with cow BW, but not with breed. The variations in NDF and iNDF concentrations between forage diets were reflected in their effects on intake, rumination, apparent digestibility, and fecal PS.
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| 12. |
- Krizsan, Sophie Julie, et al.
(författare)
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Contribution of different segments of the gastrointestinal tract to digestion in growing Saanen goats
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 1802-1814
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Tidskriftsartikel (refereegranskat)abstract
- This study examined mean retention time (MRT) of particulate and liquid matter in different segments of the gastrointestinal tract (GIT) of growing Saanen goats of different sexes and subjected to different levels of feed restriction. In addition, feeding behavior and total tract digestibility were determined for all animals ahead of slaughter. In total, 54 Saanen goats (18 each of females, castrated males, and intact males) with initial BW 15.3 +/- 0.4 kg were used in a 3 x 3 factorial arrangement comprising the 3 sexes and 3 levels of feed restriction (unrestricted/ad libitum, moderate, and severe restriction). Six blocks per sex group, each consisting of 3 goats, were randomly formed and the goats within each block were randomly allocated to 1 of 3 different feed restrictions. The daily amounts of feed offered to animals subjected to moderate and severe feed restriction (approximately 75% and 50% of ad libitum rate, respectively) were determined within block based on the DMI by ad libitum fed goats on the previous day. The MRT of particulate matter was determined either using Yb-labeled diet or indigestible NDF (iNDF) determined in situ as markers. Mean retention time of the liquid phase was determined by Cr-EDTA. Orthogonal polynomial contrasts were used to determine linear and quadratic effect of feed restriction, while the effect of sex was compared by Tukey test. The effects of sex and the interaction between sex and feed restriction were not significant on most of variables evaluated. Eating, ruminating, and total chewing time per g DM and NDF intake increased linearly as feed restriction increased (P <= 0.03). Diet digestibility increased quadratically for DM and OM, and linearly for NDF as feed intake decreased (P <= 0.03). The MRT of iNDF in the reticulorumen, omasum, abomasum, colon, and total GIT increased linearly with increased feed restriction (P <= 0.01). Mean retention time in the cecum varied quadratically, being greatest for animals with moderate feed restriction. The MRT of liquid was quadratically (P <= 0.04) affected by feed restriction in the reticulorumen, cecum, and total GIT, with the greatest MRT observed for animals subjected to moderate feed restriction. In conclusion, the level of feed restriction increased the MRT of particulate and liquid matter. The MRT was an important mechanism to increase nutrient supply when animals were subjected to feed restriction, as indicated by increased total tract digestibility.
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| 13. |
- Krizsan, Sophie Julie, et al.
(författare)
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Retention time of digesta in the gastrointestinal tract of growing Saanen goats
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 3969-3978
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the effect of increased BW on mean retention time (MRT) of both particulate and solute marker, gastrointestinal tract (GIT) development, and fiber digestion in the whole tract of growing Saanen goats using the slaughter technique. A total of 58 Saanen goats with initial BW of 15.7 +/- 0.9 kg were allocated into 9 treatments with a 3 x 3 factorial arrangement consisting of 3 sexes (female, castrated males, and intact males) and 3 slaughter weights (initial, intermediate, and final; target BW of 16, 23, and 30 kg at slaughter, respectively). They were fed twice daily (0700 and 1600 h) with the identical diets for ad libitum intake. Mean retention time of particulate matter was estimated by in situ determination of indigestible NDF (iNDF), and the MRT of solute marker was determined by Cr-EDTA. Treatment effects were evaluated in a split-plot design, with sex as the main plot and slaughter weight as the subplot. Orthogonal polynomial contrasts were used to determine linear and quadratic effects of slaughter weight, whereas the effect of sex was compared using the Tukey test. The effects of sex and sex x slaugh-ter weight were not significant for most of variables evaluated. The results showed that DMI (% BW) linearly decreased as slaughter weight increased (P < 0.01). Generally wet weight of the total GIT tissues (% BW) decreased and digesta pool sizes (g) linearly increased with increasing slaughter weight (P = 0.05). The ratio of iNDF: NDF for both ingested diet and reticulorumen digesta linearly increased as slaughter weight increased (P = 0.05). The MRT of particles did not change with increasing slaughter weight (P = 0.94). Mean retention time of particulate matter linearly increased in the omasum but linearly decreased in the abomasum with increasing slaughter weight (P < 0.01). Mean retention time of solute marker in the forestomachs linearly increased with increasing slaughter weight (P < 0.01). The results revealed a decreased selectivity with increasing BW, as supported by a greater ratio of iNDF: NDF for ingested diet. Increasing BW led to neither a longer particle MRT in the reticulorumen nor a digestive advantage. The results also indicated that, on average, 91% of fiber digestion occurred in the forestomachs of the goats.
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| 14. |
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| 15. |
- Lindholm, Caroline, et al.
(författare)
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Growth heterogeneity in broiler breeder pullets is settled before the onset of feed restriction but is not predicted by size at hatch
- 2017
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Ingår i: Journal of Animal Science. - Champaign, IL, United States : American Society of Animal Science. - 0021-8812 .- 1525-3163. ; 95:1, s. 182-193
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Tidskriftsartikel (refereegranskat)abstract
- Uniform growth is a desirable trait in all large-scale animal production systems because it simplifies animal management and increases profitability. In parental broiler flocks, so-called broiler breeders, low growth uniformity is largely attributed to the feed competition that arises from quantitatively restricted feeding. As feed restriction is crucial to maintaining healthy and fertile breeders, several practices for reducing feed competition and the associated growth heterogeneity have been suggested and range from nutrient dilution by increasing fiber content in feed to intermittent fasting with increased portion size (“skip a day”), but no practice appears to be entirely effective. The fact that a large part of the heterogeneity remains even when feed competition is minimized suggests that some growth variation is caused by other factors. We investigated whether this variation arises during embryonic development (as measured by size at hatch) or during posthatch development by following the growth and body composition of birds of varying hatch sizes. Our results support the posthatch alternative, with animals that later grow to be small or large (here defined as >1 SD lighter or heavier than mean BW of the flock) being significantly different in size as early as 1 d after gaining access to feed (P < 0.05). We then investigated 2 possible causes for different postnatal growth: that high growth performance is linked 1) to interindividual variations in metabolism (as measured by cloacal temperature and verified by respirometry) or 2) to higher levels of social motivation (as measured in a social reinstatement T-maze), which should reduce the stress of being reared in large-scale commercial flocks. Neither of these follow-up hypotheses could account for the observed heterogeneity in growth. We suggest that the basis of growth heterogeneity in broiler breeder pullets may already be determined at the time of hatch in the form of qualitatively different maternal investments or immediately thereafter as an indirect result of differences in incubation conditions, hatching time, and resulting fasting time. Although this potential difference in maternal investment is not seen in body mass, tarsometatarsal length, or full body length of day-old chicks arriving at the farm, it may influence the development of differential feed and water intake during the first day of feeding, which in turn has direct effects on growth heterogeneity.
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| 16. |
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| 17. |
- Mao, Xiaowei, et al.
(författare)
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Genome-wide association studies of growth traits in three dairy cattle breeds using whole-genome sequence data
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94, s. 1426-1437
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Tidskriftsartikel (refereegranskat)abstract
- Male calves and culled cows of dairy cattle are used for beef production. However, unlike beef breeds, the genetics of growth performance traits in dairy breeds have not been extensively studied. Here, we performed a genome-wide association study (GWAS) on Holsteins (n = 5,519), Jerseys (n = 1,231), and Red Dairy Cattle (n = 4,410) to identify QTL for growth traits. First, a GWAS was performed within breeds using whole-genome sequence variants. Later, a meta-analysis was performed to combine information across the 3 breeds. We have identified several QTL that have large effects on growth traits in Holsteins and Red Dairy Cattle but with little overlap across breeds. Only 1 QTL located on chromosome 10 was shared between Holsteins and Red Dairy Cattle. The most significant variant (BTA10:59,164,533, rs43636323; P-value = 2.8 × 10-32) in this QTL explained 2.4% of the total additive genetic variance in Red Dairy Cattle. The gene CYP19A1 is a strong candidate for the underlying gene of this QTL. In Red Dairy Cattle, a QTL near 25 Mb on chromosome 14 was very significantly associated with growth traits, consistent with the previously reported gene PLAG1, which affects growth in beef cattle and humans. No QTL for growth performance was statistically significant in Jerseys, possibly due to the low power of detection with the small sample size. The meta-analysis of the 3 breeds increased the power to detect QTL.
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| 18. |
- Nadeau, Elisabet, et al.
(författare)
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Digestibility and protein utilization in wethers fed whole-crop barley or grass silages harvested at different maturity stages, with or without protein supplementation
- 2019
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 97, s. 2188-2201
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Tidskriftsartikel (refereegranskat)abstract
- Effects of whole-crop barley and grass silages harvested at different maturity stages, with or without protein supplementation, on intake, in vivo digestibility, feces characteristics, and protein utilization in wethers were evaluated. Whole-crop barley silage harvested at heading stage (BH) and at medium milk stage (BM), grass silage (GE) taken at the flag leaf-early heading stage, and grass silage (GL) taken at medium-late heading stage were fed to eight wethers in two 4 x 4 Latin squares. Wethers in one square were fed supplementary rapeseed meal. Experimental periods lasted for 4 wk and wethers were fed ad libitum during the first 3 wk, with intake recorded during the third week. During the fourth week, wethers were fed 80% of ad libitum, and feces and urine were collected during the last 4 d. The GE and BH diets had greater (P < 0.05) in vivo apparent digestibility of DM and its nutrients, lower proportion of fecal particle DM (PDM) with a greater proportion of small particles compared with GL and BM diets, respectively. The GE diet had greater (P < 0.001) in vitro OM digestibility and in vivo digestibility of OM and fibre, resulting in a smaller (P < 0.001) proportion of PDM with a greater (P < 0.001) proportion of small particles compared with the other diets. In vivo NDF digestibility was negatively related to fecal PDM across forage types (R-2 = 0.91, RMSE = 2.55). The GE silage had greater CP concentration, and animals fed the GE diet had greater intake of CP (P < 0.001) and sum of the degradable CP fractions A, B-1, and B-2 (P < 0.01), resulting in greater (P < 0.05) urinary nitrogen (N) excretion than when fed any of the other diets and a lower (P < 0.05) N retention compared with BH and BM diets. Microbial N supply tended to increase when animals were fed the BH diet (P = 0.10) and when rapeseed meal was added to the forages (P = 0.08). Increased N intake (P = 0.008) by rapeseed meal supplementation increased urinary N excretion in gram per day (P = 0.05). The strong relationship between in vivo NDF digestibility and fecal PDM indicates potentials for using PDM as a cheap method to predict NDF digestibility. Early harvest of the forages improved in vivo digestibility of nutrients, resulting in less fecal PDM with a greater proportion of small particles compared with late harvest within forage type. However, wethers fed the GE diet had greater urinary N losses compared with wethers fed the GL diet but this effect of maturity was absent when fed whole-crop barley silage.
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| 19. |
- Nadeau, Elisabet, et al.
(författare)
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Protein quality of grass silage as affected by silage additives and its effects on dairy cow performance
- 2015
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Ingår i: Journal of Animal Science. - 0021-8812 .- 1525-3163. ; 93, s. 206-
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Konferensbidrag (refereegranskat)abstract
- This experiment was conducted to evaluate the effects of improved protein quality of grass silage by additive use on dairy cow intake and performance. Grass from the first regrowth was wilted to 33% DM before being precision chopped and treated with the inoculant Kofasil Duo (Lactobacillus plantarum/Lactobacillus buchneri, 200,000 cfu/g) or with the chemical additive Kofasil Ultra K (sodium nitrite, hexamine, potassium sorbate, sodium benzoate and sodium propionate, 2 L/T, Addcon Europe GmbH), which were compared with a control without additive. The forage was ensiled in hard-pressed round bales before being fed to 48 dairy cows (150 DIM) in a continuous trial for 9 wk using 8 cows per treatment. Cows were blocked according to breed, parity, DIM and milk yield. The silage contained 15% CP, 47% NDF, 3.3% WSC, 8.2% lactic acid, 2.1% acetic acid and 0.25% NH3-N of DM with minor differences between treatments. Rumen undegradable protein (RUP) of the silage at 5% passage rate was 22, 23 and 24% of CP for control (C), inoculant (I) and salt-based (S) additive, respectively. Diets were isonitrogenous (15.1% of DM) and isoenergetic (11.4 MJ/kg DM) varying in RUP (4.7% (high) and 2.5% (low) of DM). Concentrate UDP was 2.9 and 8.6% of DM. Dietary forage proportion of the TMR was 58% of DM. Data were analyzed using PROC MIXED of SAS with RUP, silage and week as fixed factors and block as a random factor. High RUP diet had higher milk yield than low RUP diet (29.4 vs. 27.9 kg; P < 0.05). The DM intake was not affected by RUP and silage treatment. Yields of milk and ECM were higher for the I and S diets than for the C diet at low RUP (28.9 vs. 26.0 kg milk, P < 0.01; 30.6 vs. 27.1 kg ECM, P < 0.001) whereas there was no effect of additive treatment in the high RUP diet. Milk fat and protein did not differ between silage treatments. Feed efficiency was higher for the I and S diets than for the C diet at the low RUP (1.6 vs. 1.3 kg of ECM/kg DM intake, P < 0.001) but not at the high RUP. The increased milk yield and feed efficiency when fed a diet with low RUP can partly be explained by increased RUP of the I and S silages.
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| 20. |
- Prykhodko, O., et al.
(författare)
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Early treatment with pancreatic-like microbial-derived enzymes during the preweaning period promotes growth in growing–finishing pigs
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94:7, s. 150-152
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Tidskriftsartikel (refereegranskat)abstract
- Treatment with pancreatic or pancreatic-like microbial enzymes during the suckling period has positive effects on the gut, resulting in a better fat absorption and improved barrier function in pigs. The present study investigated the effects of pancreaticlike enzyme treatment during the pre- or postweaning period on pig growth and nitrogen utilization. Suckling 7- to 14-d-old pigs were gavage fed with a microbial-derived enzyme preparation (amylase, protease, and lipase) in a split-litter mode (13 litters) once (n = 29), twice (n = 35), or untreated (controls; n = 66). All pigs were then raised under the same standard production conditions and received the same diets, and their BW and feed intake were monitored until slaughter. Another set of 35-d-old pigs, on the day of weaning, were placed in metabolic cages and fed a diet with or without enzyme supplementation for 2 wk (n = 4/group). Feed consumption was measured daily, and at the end of each week, BW was recorded and urine and feces were collected during 72 h for nitrogen analysis. Dietary enzyme supplementation after weaning in selected doses had no major effect on feed consumption, nitrogen retention, or growth compared with the control. In contrast, enzyme treatment during the suckling period gave improved growth, with increased BW at 6 mo of age, 105 ± 16 vs. 97 ± 15 kg for the controls (P < 0.05), and those pigs reached slaughter weight earlier than untreated controls. In addition, the feed conversion ratio was significantly decreased, thus lowering nitrogen excretion per kilogram BW gain in the enzymetreated group compared with the untreated controls (3.0 vs. 2.7, respectively). We conclude that enzyme supplementation during the suckling period was beneficial for both pig performance and environment protection, probably due to an induced improved maturation of the gut having a long-term impact on feed utilization and growth after weaning.
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| 21. |
- Raymond, Biaty, et al.
(författare)
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Genome-wide association study for bone strength in laying hens
- 2018
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Ingår i: Journal of animal science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 96, s. 2525-2535
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Tidskriftsartikel (refereegranskat)abstract
- Bone fracture in egg laying hens is a growing welfare and economic concern in the industry. Although environmental conditions and management (especially nutrition) can exacerbate it, the primary cause of bone weakness and the resulting fractures is believed to have a genetic basis. To test this hypothesis, we performed a genome-wide association study to identify the loci associated with bone strength in laying hens. Genotype and phenotype data were obtained from 752 laying hens belonging to the same pure line population. These hens were genotyped for 580,961 SNPs, with 232,021 SNPs remaining after quality control. Each of the SNPs were tested for association with tibial breaking strength using the family-based score test for association. A total of 52 SNPs across chromosomes 1, 3, 8, and 16 were significantly associated with tibial breaking strength with the genome-wide significance threshold set as a corrected P value of 10e-5. Based on the local linkage disequilibrium around the significant SNPs, 5 distinct and novel QTLs were identified on chromosomes 1 (2 QTLs), 3 (1 QTL), 8 (1 QTL) and 16 (1 QTL). The strongest association was detected within the QTL region on chromosome 8, with the most significant SNP having a corrected P value of 4e-7. A number of candidate genes were identified within the QTL regions, including the BRD2 gene that is required for normal bone physiology. Bone-related pathways involving some of the genes were also identified including chloride channel activity, which regulates bone reabsorption, and intermediate filament organization, which plays a role in the regulation of bone mass. Our result supports previous studies that suggest that bone strength is highly regulated by genetics. It is therefore possible to reduce bone fractures in laying hens through genetic selection and ultimately improve hen welfare.
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| 22. |
- Stefánsdóttir, Gudrún, et al.
(författare)
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A comparison of the physiological response to tolt and trot in the Icelandic horse.
- 2015
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 3862-3870
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Tidskriftsartikel (refereegranskat)abstract
- This study compared the effect of ridden tolt and trot at 3 speeds on physiological responses in trained adult (15.3 +/- 1.6 yr) Icelandic horses. The experiment had a crossover design with 8 horses, 2 treatments (incremental exercise test in tolt and trot), and 2 riders. Each horse performed 2 tests per day (1 gait with 2 riders, minimum 4.5 h between) on 2 separate days, with 1 d of rest in between. The exercise test consisted of three 642-m phases at 3.0 m/s (Speed(3)), 4.0 m/s (Speed(4)), and 5.0 m/s (Speed(5)) and was performed outdoors on a 300-m oval gravel riding track in northern Iceland in May 2012. Heart rate (HR) was measured during warm-up, the exercise test, and after 5, 15, and 30 min of recovery. Blood samples were taken at rest, after warm-up, after each phase of the exercise test, and after 5, 15, and 30 min of recovery. Respiratory rate was counted for at least 15 s at rest, at the end of the exercise test, and at the end of the 30-min recovery, and rectal temperature was measured on these occasions. There were no differences in HR between tolt and trot at any time point (P > 0.05). At Speed3, hematocrit and plasma lactate concentration were greater (P < 0.05) in tolt (40% +/- 1%, 1.1 +/- 0.06 mmol/L) than in trot (39% +/- 1%; 0.9 +/- 0.06 mmol/L). There was a prolonged recovery of hematocrit and respiratory rate, a slower decrease in rectal temperature, and a tendency of a prolonged recovery of plasma lactate concentration (P = 0.0675) after tolt. In conclusion, there were only minor differences in physiological responses to tolt and trot in this selected group of experienced adult Icelandic horses and the biological and practical significance of the slightly elevated physiological responses to tolt and the slower recovery remains to be determined.
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| 23. |
- Szczurek, P., et al.
(författare)
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Effects of dietary supplementation with pancreatic-like enzymes of microbial origin (PLEM) and silicon dioxide (SiO2) on the performance of piglets fed creep feed
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94:7 Supp.3, s. 62-65
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that during the suckling period pancreatic secretion is low. The aim of the study was to investigate the effects of dietary supplementation with pancreatic-like enzymes of microbial origin (PLEM) and SiO2, as an antibacterial factor, on the performance of piglets fed creep feed during weaning and thereafter. The experiment was performed on piglets from 30 litters. The piglets were divided into 5 groups (n = 63–66) and weaned at the age of 28 d old. The control group received standard creep feed (Days 7–28), and groups P1 and P2 and groups PA1 and PA2 received creep feed with SiO2supplemented with protease (P1 and P2) or with protease+amylase (PA1 and PA2) during Days 7–13 (P1 and PA1) or Days 14–20 (P2 and PA2) before weaning. Dietary supplementation with PLEM and SiO2led to a significant (P < 0.05) increase in ADG in the treated piglets compared to the control with the best results obtained in group P2. To summarize, creep feed supplemented with PLEM improves productivity parameters of piglets under standard rearing conditions.
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| 24. |
- Tenghe, Amabel, et al.
(författare)
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Opportunities for genomic prediction for fertility using endocrine and classical fertility traits in dairy cattle
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94, s. 3645-3654
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine fertility traits, defined from progesterone concentration levels in milk, have been suggested as alternative indicators for fertility in dairy cows because they are less biased by farm management decisions and more directly reflect a cow's reproductive physiology than classical traits derived from insemination and calving data. To determine the potential use of endocrine fertility traits in genomic evaluations, the improvement in accuracy from using endocrine fertility traits concurrent with classical traits in the genomic prediction of fertility was quantified. The impact of recording all traits on all training animals was also investigated. Endocrine and classical fertility records were available on 5,339 lactations from 2,447 Holstein cows in Ireland, the Netherlands, Sweden, and the United Kingdom. The endocrine traits were commencement of luteal activity (C-LA]) and proportion of samples with luteal activity (PLA); the classical trait was the interval from calving to first service (CFS). The interval from C-LA to first service (C-LAFS), which is a combination of an endocrine trait and a classical trait, was also investigated. The target (breeding goal) trait for fertility was CFS or C-LAFS, whereas C-LA and PLA served as predictor traits. Genomic EBV (GEBV) for fertility were derived using genomic BLUP in bivariate models with 85,485 SNP. Genomic EBV for the separate fertility traits were also computed, in univariate models. The accuracy of GEBV was evaluated by 5-fold cross-validation. The highest accuracy of GEBV was achieved using bivariate predictions, where both an endocrine fertility trait and the classical fertility trait were used. Accuracy of GEBV for predicting adjusted phenotypes for CFS in the univariate model was 0.04, but when predicting CFS using a bivariate model with C-LA, the accuracy increased to 0.14 when all training animals were phenotyped for C-LA and (or not) for CFS. On phenotyping all training animals for both C-LA and CFS, accuracy for CFS increased to 0.18; however, when validation animals were also phenotyped for C-LA, there was no substantial increase in accuracy. When predicting CFS in bivariate analysis with PLA, accuracy ranged from 0.07 to 0.14. This first study on genomic predictions for fertility using endocrine traits suggests some improvement in the accuracy of prediction over using only the classical traits. Further studies with larger training populations may show greater improvements.
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| 25. |
- Zeng, Z. K., et al.
(författare)
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A new Buttiauxella phytase continuously hydrolyzes phytate and improves amino acid digestibility and mineral balance in growing pigs fed phosphorous-deficient diet
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94:2, s. 629-638
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Tidskriftsartikel (refereegranskat)abstract
- Ten ileal T-cannulated pigs (19.26 ± 1.06 kg) were used to evaluate the effects of a novel Buttiauxella phytase on apparent ileal digestibility (AID) of AA and apparent total tract digestibility (ATTD) and hindgut disappearance of DM, GE, CP, crude fiber, NDF, and ADF as well as minerals balance. Pigs were fed in a duplicated 5 × 4 incomplete Latin square design (5 diets with 4 periods). Each period consisted of a 5-d adjustment period followed by a 3-d total collection of feces and urine and then a 2-d collection of ileal digesta. The 5 diets included a P-deficient basal diet (0.43% Ca and 0.38% total P) that was supplemented with 0 (negative control [NC]), 500, 1,000, or 20,000 phytase units (FTU)/kg phytase and a positive control (PC) diet that was P adequate (0.64% Ca and 0.52% total P). The addition of phytase to the NC diet improved (P < 0.05) AID of phytate from 11.1 to 62.8, 70.6, and 90.5% at the inclusion rates of 500, 1,000, and 20,000 FTU/kg, respectively. In general, phytase supplementation at a dose of 20,000 FTU/kg further increased (P < 0.05) AID of Ca, total P, and phytate and reduced (P < 0.05) the ileal phytate concentration compared with diets with 500 or 1,000 FTU/kg phytase. Pigs fed the diet with 20,000 FTU/kg phytase but not diets with 500 and 1,000 FTU/kg phytase showed improved (P < 0.05) ATTD of CP and AID of DM, GE, CP, Leu, Lys, Thr, Val, Asp, and Ser compared with pigs fed the PC or NC diet. However, hindgut disappearance of crude fiber and NDF (P < 0.05) were reduced in pigs fed the diet with 20,000 FTU/kg phytase compared with pigs fed the PC or NC diet. Pigs fed diets with 500 or 1,000 FTU/ kg phytase had greater ATTD and retention of Ca and P than pigs fed the NC diet but less compared with pigs fed the diet with 20,000 FTU/kg phytase. Supplementation of 20,000 FTU/kg phytase to the NC diet improved (P < 0.05) digestibility of Na, Mn, and Zn as well as retention (%) of Zn. Increasing phytase supplementation doses from 0 to 1,000 FTU/kg linearly improved (P < 0.05) retention of Mg; meanwhile, digestibility of Mg and Mn and AID of Thr showed a linear increase trend (P = 0.084). In conclusion, supplementation of the novel Buttiauxella phytase at doses up to 20,000 FTU/kg hydrolyzed most of the phytate (90%) and consequently further improved mineral and protein utilization.
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