| 1. |
- Bolarin, A., et al.
(author)
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Use of frozen-thawed semen aggravates the summer-autumn infertility of artificially inseminated weaned sows in the Mediterranean region
- 2009
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In: Journal of Animal Science. - : American Society of Animal Science. - 0021-8812 .- 1525-3163. ; 87:12, s. 3967-3975
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Journal article (peer-reviewed)abstract
- Improvement of farrowing rate (FR) and litter size (LS) of sows that are AI with frozen-thawed (FT) semen can hardly be reached without identification of the factors behind the high variability seen among trials. Three experiments using weaned (4-d wean-to-estrus interval) multiparous (parity 2 to 7) sows were conducted to evaluate the effect of period of the year on FR and LS of FT-inseminated sows in southern Spain. Sows were grouped into 2 periods of the year: winter-spring (November to April; WS) and summer-autumn (May to October; SA). Ovarian status was monitored by transrectal ultrasonography to record how long before or after ovulation AI was performed (pre-, peri-, or postovulatory AI) and to determine the onset of estrus-to-ovulation interval (EOI). Inseminations were performed using deep intrauterine AI with 1.5 x 109 FT sperm per dose. The first experiment was designed to determine the influence of the period of the year on FR and LS of FT semen. Sows (116 in WS and 100 in SA) were AI at 33 and 39 h after the onset of estrus. The period of the year influenced the FR and LS (P less than 0.01). Farrowing rate and LS were least in SA (P less than 0.05). This pattern of annual variation was similar to that shown by sows on the same farm currently undergoing AI with liquid semen (cervical AI at 12 and 36 h after the onset of estrus with 3 x 109 sperm per dose). However, the FR reduction in SA respect to WS was more substantial in sows artificially inseminated with FT (77.6 vs. 50%, P less than 0.001) than those artificially inseminated with liquid semen (83.9 vs. 71.8%, P less than 0.05). More pre- and less periovulatory AI were performed in SA sows than in WS sows (P = 0.05). Experiment 2 was designed to evaluate whether the period of the year influenced EOI. Ovarian status was transrectal ultrasonography scanned every 6 h after the onset of estrus until the end of ovulation (WS: 30; SA: 31 sows). There were more sows with long EOI (greater than48 h) in SA than in WS (P = 0.05). Experiment 3 aimed to improve the reduced FR and LS recorded in SA sows when using FT semen (Exp. 1) by inducing ovulation with eCG + hCG. A single AI with FT semen was performed 5 h before the expected ovulation (55 sows). As a control, spontaneously ovulating sows (n = 53) were FT-inseminated as in Exp. 1. Hormonal induction of ovulation did not improve FR and LS (P greater than 0.05). In the Spanish Mediterranean area, a longer EOI during SA negatively influenced the FR and LS of weaned sows after AI. This effect was particularly evident when FT semen was used. These findings were not ameliorated by hormonal induction of ovulation.
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| 2. |
- Lundeheim, Nils, et al.
(author)
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Genetic validation of postmixing skin injuries in pigs as an indicator of aggressiveness and the relationship with injuries under more stable social conditions
- 2009
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 87, s. 3076-3082
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Journal article (peer-reviewed)abstract
- The objective of the study was to estimate genetic correlations between skin lesions and aggressive behavior postmixing and under more stable social conditions as a potential means of selecting against pig aggressiveness. Postmixing aggression in commercial pig production is common, compromises welfare and profitability, and cannot be significantly reduced by low-cost changes to the environment. A genetic component to individual aggressiveness has been described in pigs and other species. Selective breeding against aggressiveness ought to be possible if an easily measured indicator trait can be shown to be genetically associated with aggressive behavior. Aggressive behavior was recorded continuously for 24 h after mixing, and a count of skin lesions (lesion count, LC) was recorded at 24 h and 3 wk postmixing on 1,663 pigs. Two behavioral traits were found to have a moderate to high heritability similar to that of growth traits; duration of involvement in reciprocal fighting (0.43 +/- 0.04) and delivery of nonreciprocal aggression (NRA; 0.31 +/- 0.04), whereas receipt of NRA had a lower heritability (0.08 +/- 0.03). Genetic correlations (r(g)) suggested that lesions to the anterior region of the body 24 h after mixing were associated with reciprocal fighting (r(g) = 0.67 +/- 0.04), receipt of NRA (r(g) = 0.70 +/- 0.11), and to a lesser extent, delivery of NRA (r(g) = 0.31 +/- 0.06). Lesions to the center and rear were primarily genetically associated with receipt of NRA (r(g) = 0.80 +/- 0.05, 0.79 +/- 0.05). Genetic correlations indicated that pigs that engaged in reciprocal fighting delivered NRA to other animals (r(g) = 0.84 +/- 0.04) but were less likely to receive NRA themselves (r(g) = -0.41 +/- 0.14). A genetic merit index using lesions to the anterior region as one trait and those to the center or rear or both as a second trait should allow selection against animals involved in reciprocal fighting and the delivery of NRA. Positive correlations between LC 24 h and 3 wk after mixing were found, especially for lesions to the center and rear of the body, indicating that postmixing lesions are predictive of those received under more stable group conditions. As well as reducing immediate aggression at mixing, selection on postmixing LC is expected to have a long-term impact on injuries from aggression, even after dominance relationships are established.
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| 3. |
- Muhonen, Sara, et al.
(author)
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Effects on the equine colon ecosystem of grass silage and haylage diets after an abrupt change from hay
- 2009
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 87, s. 2291-2298
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Journal article (peer-reviewed)abstract
- The objective of this study was to investigate the effect of an abrupt change from grass hay (81% DM) to grass silage (36% DM) or grass haylage (55% DM), fed at similar DM intakes, and to compare the effects of silage and haylage on the composition and activities of the colon microflora. The forages were from the same swath harvested on the same day. Four adult colon-fistulated geldings were randomly assigned to diets in a crossover design. The study started with a preperiod when all 4 horses received the hay diet, followed by an abrupt feed change to the haylage diet for 2 horses and the silage diet for 2 horses. All 4 horses then had a new second preperiod of hay, followed by an abrupt feed change to the opposite haylage and silage diet. The periods were 21 d long, and the forage-only diets were supplemented with minerals and salt. The abrupt feed changes were made at 0800 h. Colon samples were taken before the abrupt feed change, 4 and 28 h after the feed change, and 8, 15, and 21 d after the feed change, all at 1200 h. Colon bacterial counts, VFA, pH, and DM concentrations were unchanged throughout the first 28 h after the abrupt feed change from hay to haylage and silage. Also, fecal pH and DM concentrations were unchanged during the first 28 h. During the weekly observations, colon lactobacilli counts increased (P = 0.023) in horses receiving the silage diet and were greater than on the haylage diet at 21 d. Streptococci counts decreased (P = 0.046) in horses receiving the haylage diet and were less than on the silage diet at 15 and 21 d. Total VFA concentrations and colon and fecal pH did not differ between diets and were unchanged throughout the weekly observations. The DM concentration of colon digesta and feces decreased (P = 0.030 and 0.049, respectively) on both diets during the weekly observations. The results suggest that in horses fed at the maintenance level of energy intake, an abrupt feed change from grass hay to grass silage or grass haylage from the same crop does not induce any major alterations in the colon ecosystem during the first 28 h. During the subsequent 3-wk period, colon and fecal DM decreased and there were alterations in the lactobacilli and streptococci bacterial counts. The changes in lactobacilli and streptococci counts need further investigation.
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| 4. |
- Pabiou, Thierry, et al.
(author)
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Genetic parameters for carcass cut weight in Irish beef cattle
- 2009
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 87, s. 3865-3876
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Journal article (peer-reviewed)abstract
- The objective of this study was to estimate genetic parameters for the weights of different wholesale cuts, using an experimental and a commercial data set. The experimental and commercial data sets included 413 and 635 crossbred Belgian Blue, Charolais, Limousin, Angus, Holstein, and Simmental animals, respectively. Univariate analyses using a mixed linear animal model with relationships were undertaken to estimate the heritability of cold carcass weight, carcass conformation and fat, and the cut weights, whereas a series of bivariate analyses was used to estimate the phenotypic and genetic correlations between carcass weight, carcass conformation, carcass fat, and the major primal cuts. Heritability estimates for cold carcass weight in both data sets were moderate (>0.48), whereas heritability estimates for carcass conformation and fat grading were greater in the commercial data set (>0.63) than in the experimental study (>0.33). Across both data sets, heritability estimates for wholesale cut weight in the forequarter varied from 0.03 to 0.79, whereas heritability estimates of carcass cut weight in the hindquarter varied from 0.14 to 0.86. Heritability estimates for cut weights expressed as a proportion of the entire carcass weight varied from 0.04 to 0.91. Genetic correlations were strong among the different carcass cut weights within the experimental and the commercial studies. Genetic correlations between the weights of selected carcass cuts and carcass weight were moderate to high (minimum 0.45; maximum 0.88) in both data sets. Positive genetic correlations were observed in the commercial data set between the different wholesale cut weights and carcass conformation, whereas these were positive and negative in the experimental data set. Selection for increased carcass weight will, on average, increase the weight of each cut. However, the genetic correlations were less than unity, suggesting a benefit of more direct selection on high value cuts.
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| 5. |
- Thirstrup, J. P., et al.
(author)
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Population viability analysis on domestic horse breeds (Equus caballus)
- 2009
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 1525-3163 .- 0021-8812. ; 87:11, s. 3525-3535
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Journal article (peer-reviewed)abstract
- In this study, we performed a population viability analysis on 3 domestic horse breeds (Equus caballus) of Danish origin, namely, the Frederiksborg, the Knabstrupper, and the Jutland breeds. Because of their small population sizes, these breeds are considered endangered. The Vortex software simulation package was used for the population viability analysis. First, we investigated the future viability of these breeds based on present demographic and environmental parameters. Second, a sensitivity analysis revealed the most important variables for the viability of these breeds. Third, we examined management scenarios in which one of the studbooks was closed. According to the Vortex analysis, 2 of the breeds (Knabstrupper and Jutland) will persist for the next 200 yr, whereas the smaller breed (Frederiksborg) could become extinct within 40 yr. The sensitivity analyses indicated that the variables concerning reproduction of the mares had the greatest impact, with the number of mares actively breeding being the most influential on the population forecasts. The results suggest that closing the Knabstrupper studbooks can be done only if increasing the number of mares actively breeding counteracts the loss of genetic variation attributable to such a management strategy. It is recommended, based on these results, that the number of Frederiksborg and Knabstrupper mares actively breeding must be increased to approximately 30% in the 2 breeds that are presently using only 13%, while leaving the third (Frederiksborg) at its present 30% level. Monitoring of the breeds in the future, however, may be exploited to adjust the breeding strategies. We suggest that the large amount of data required by Vortex makes it very useful for analyzing domestic animals because of the comprehensive data material often available. The results of this analysis accord with other studies on the Prezwalski horse, indicating robustness in the parameter sensitivity for horses.
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| 6. |
- Thomsson, Annika, et al.
(author)
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Effects of crude red kidney bean lectin (phytohemagglutinin) exposure on performance, health, feeding behavior, and gut maturation of pigs at weaning
- 2007
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 1525-3163 .- 0021-8812. ; 85:2, s. 477-485
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Journal article (peer-reviewed)abstract
- The aim of this study was to obtain information that could help to ease the weaning transition in commercial pig production. Before weaning, phytohemagglutinin (PHA) in the form of a crude preparation of red kidney bean lectin was fed by gavage to 24 crossbred [(Swedish Landrace x Yorkshire) x Hampshire] piglets, whereas 24 control piglets were fed -lactalbumin by gavage, to study the effect on growth, occurrence of postweaning diarrhea, feeding behavior, and some anatomical and physiological traits of the gastrointestinal tract. Within the litter, piglets were randomly assigned to PHA treatment or control and remained in the same pen from the beginning (PHA exposure at 7 d before weaning) until the end of the experiment (14 d post-weaning). Weaning took place at the age of 31 to 34 d. Pigs treated with PHA grew faster (P = 0.013) during the first week postweaning and tended to have lower total diarrhea scores (P = 0.10) than did control pigs. On d 5 after weaning, piglets treated with PHA spent more time eating (P = 0.028) than control pigs. No immunostimulating effect of PHA, measured by plasma immunoglobulin G, could be detected. An increase in the intestinal barrier properties before weaning, as a response to PHA treatment, was demonstrated in intestinal absorption studies using Na-fluorescein and BSA as gavage-fed markers. Less uptake (measured as plasma concentrations) of the marker molecule Na-fluorescein occurred during a 24-h study period, and numerically lower levels of BSA were observed compared with studies in control pigs of the same age. A total of 12 pigs (6 control, 6 PHA-treated) were euthanized on the day of weaning for analyses of gastrointestinal properties. The PHA-treated pigs tended to have a longer total small intestinal length (P = 0.063) than that of the control pigs. The enzyme profile of the jejunal epithelium responded to PHA exposure with a decrease in lactase activity and an increase in maltase and sucrase activities, which is similar to changes normally observed after weaning. No differences were found in the size of the pancreas or in its contents of trypsin and amylase. In conclusion, exposing piglets to crude, red kidney bean lectin for 3 d during the week before weaning led to changes in performance and small intestinal functional properties that would be expected to contribute to a more successful weaning.
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| 7. |
- van den Borne, Jost, et al.
(author)
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Exocrine pancreatic secretion in pigs fed sow's milk and milk replacer, and its relationship to growth performance
- 2007
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 1525-3163 .- 0021-8812. ; 85:2, s. 404-412
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Journal article (peer-reviewed)abstract
- The objective of this study was to quantify and compare the effects of sow’s milk and 2 milk replacer diets (containing clotting or nonclotting protein sources) on exocrine pancreatic secretion, plasma cholecystokinin, and immunoreactive cationic trypsin in pigs. In addition, the relationship between exocrine pancreatic secretion and growth in milk-fed pigs was studied. In a changeover experiment, 9 chronically catheterized pigs of 6.6 ± 0.19 kg of BW were studied for 3 wk. Pigs were assigned to each of 3 diets. Exocrine pancreatic secretion was measured from the third to the seventh day on each diet. The protein content and trypsin activity of the pancreatic juice were measured. Blood samples were taken at 10 min before and after milk ingestion and were analyzed for cholecystokinin and immunoreactive cationic trypsin. Pancreatic protein and trypsin secretion did not differ between pigs fed sow’s milk and those fed milk replacer, but the volume secreted was less for the pigs fed sow’s milk (0.75 vs. 1.03 mL·kg–1·h–1; P < 0.01). A postprandial response to milk intake was not observed. The 2 milk replacer diets did not affect exocrine pancreatic secretion differently. The average exocrine pancreatic secretion (volume, 0.94 mL·kg–1·h–1; protein, 4.28 mg·kg–1·h–1; trypsin, 1.65 U·kg–1·h–1) was intermediate between literature values for suckling and weaned pigs. Plasma cholecystokinin was elevated (18 pmol·L–1) and showed low correlations with the pancreatic secretion traits. Plasma immunoreactive cationic trypsin was not significantly related to any of the pancreatic secretion traits and should therefore not be used as an indicator for exocrine pancreatic function in milk-fed pigs. Exocrine pancreatic secretion varied substantially among individual pigs (protein, 0.22 to 13.98 mg·kg–1·h–1). Pancreatic protein and trypsin secretion showed a positive, nonlinear relationship with performance traits. It was concluded that neither specific sow’s milk ingredients nor the protein source are responsible for a low pancreatic protein secretion in suckling pigs. Exocrine pancreatic secretion was positively correlated with ADG in pigs at an identical milk intake.
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