| 1. |
- Arvidsson Segerkvist, Katarina
(author)
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Effects of capric acid on rumen methanogenesis and biohydrogenation of linoleic and alpha-linolenic acid
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 810-816
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Journal article (peer-reviewed)abstract
- Capric acid (00:0), a medium chain fatty acid, was evaluated for its anti-methanogenic activity and its potential to modify the rumen biohydrogenation of linoleic (C18:2n-6) and alpha-linolenic acids (083n-3). A standard dairy concentrate (0.5 g), supplemented with sunflower oil (10 mg) and linseed oil (10 mg) and increasing doses of capric acid (0, 10, 20 and 30 mg), was incubated with mixed rumen contents and buffer (1: 4 v/v) for 24 h. The methane inhibitory effect of capric acid was more pronounced at the highest (30 mg) dose compared to the medium (20 mg) (-85% v. -34%), whereas the lower dose (10 mg) did not reduce rumen methanogenesis. A 23% decrease in total short-chain fatty acid (SCFA) production was observed, accompanied by shifts towards increased butyrate at 20 mg and increased propionate at 30 mg of capric acid (P < 0.001). Capric acid linearly decreased the extent of biohydrogenation of C18:2n-6 and C18:3n-3, by up to 60% and 86%, respectively. This reduction was partially due to a lower extent of lipolysis when capric acid was supplemented. Capric acid at 20 and 30 mg completely inhibited the production of C18:0 (P < 0.001), resulting in an accumulation of biohydrogenation intermediates, mainly 08:1110 + t11 and C18:2t11c15. In contrast to effects on rumen fermentation (methane production and proportions of SCFA), 30 mg of capric acid did not induce major changes in rumen biohydrogenation as compared to the medium (20 mg) dose. This study revealed the dual action of capric acid, being inhibitory to both methane production and biohydrogenation of C18:2n-6 and C18:3n-3.
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| 2. |
- Carlén, Emma, et al.
(author)
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Random regression models for genetic evaluation of clinical mastitis in dairy cattle
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1100-1108
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Journal article (peer-reviewed)abstract
- A genetic analysis of longitudinal binary clinical mastitis (CM) data recorded on about 90000 first-lactation Swedish Holstein cows was carried out using linear random regression models (RRM). This method for genetic evaluation of CM has theoretical advantages compared to the method of linear cross-sectional models (CSM), which is currently being used The aim of this study was to investigate the feasibility and suitability of estimating genetic parameters and predicting breeding values for CM with a linear sire RRM. For validation purposes, the estimates and predictions from the RRM were compared to those from linear sire longitudinal multivariate models (LMVM) and CSM. For each cow, the period from 10 days before to 241 days after calving was divided into four 1-week intervals followed by eight 4-week intervals. Within each interval, presence or absence of CM was scored as '1' or '0' The linear RRM used to explain the trajectory of CM over time included a set of explanatory variables plus a third-order Legendre polynomial function of time for the sire effect The time-dependent heritabilities and genetic correlations from the chosen RRM corresponded fairly well with estimates obtained from the linear LMVM for the separate intervals. Some discrepancy between the two methods was observed, with the more unstable results being obtained from the linear LMVM. Both methods indicated clearly that CM was not genetically the same trait throughout lactation. The correlations between predicted sire breeding values from the RRM, summarized over different time periods, and from linear CSM were rather high. They were, however, less than unity (0.74 to 0.96), which indicated some re-ranking of sires. Sire curves based on the time-specific breeding values from the RRM illustrated differences in intercept and slope among the best and the worst sires. To conclude, a linear sire RRM seemed to work well for genetic evaluation purposes, but was sensitive for estimation of genetic parameters.
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| 3. |
- Engblom, Linda, et al.
(author)
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Genetics of crossbred sow longevity
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 783-790
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Journal article (peer-reviewed)abstract
- The aim of this study was to estimate genetic parameters for longevity from Swedish crossbred sows to investigate the possibilities of selecting for this trait. Data were collected from 16 commercial piglet-producing herds, on crossbred (Landrace x Yorkshire) sows farrowing in the period 1 January 2001 to 31 December 2004. The data set with records on 10373 sows was split into two sets according to the breed of the sire, i.e. Landrace sires (LS) or Yorkshire sires (YS). Removal hazard during productive life (PL) was analysed with survival analysis, using a sire model. Stayability from first to second litter (STAY12), stayability from first to third litter (STAY13), length of productive life (LPL) and lifetime production (LTP) were analysed with linear models, using an animal model. Females after the worst sire had 1.7 times higher (progeny of LS) and 2.4 times higher (progeny of YS) risk of removal than females after the best sire. Heritability for PL was estimated at 0.06 (LS) and 0.12 (YS). The heritabilities for the linear longevity traits ranged from 0.03 to 0.08. Genetic correlations between the four linear longevity traits were all high and positive (0.6 to 1.0), as were the phenotypic correlations (0.5 to 0.8). The correlations (Spearman rank) between the sire's estimated breeding values for all the five longevity traits were all significant (P < 0.001) and moderate to strong in both data sets. Estimated breeding value (EBV) correlations between the five longevity traits and traits included in the present Swedish breeding evaluation (Quality Genetics (QG)) were significant in a few cases. Significant and favourable EBV correlations were found between age at first farrowing and both STAY12 and STAY13 (-0.20 and -0.31), as well as between litter weight at 3 weeks and LPL and UP (0.13 to 0.20). Significant and unfavourable EBV correlations were found between age at 100 kg and STAY12 (0.32), as well as between the exterior conformation score from testing station and PL (-0.20). The level of the estimated heritabilities for longevity indicates that genetic improvement of sow longevity would be possible. However, overall, there was no strong indirect selection for sow longevity with the current Swedish breeding evaluation (QG).
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| 4. |
- Forsbäck, Linda, et al.
(author)
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Udder quarter milk composition at different levels of somatic cell count in cow composite milk
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 710-717
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Journal article (peer-reviewed)abstract
- Automatic milking systems have made possible the separation of high- and low-quality milk at the udder quarter level during the milking process. The aim of this study was to investigate the composition and yield of milk from individual udder quarters to determine whether deteriorated milk composition occurs in udders that are assumed to be healthy and whether quarters with high-quality milk are found in udders with high milk somatic cell count (SCC). Milk samples were collected on one occasion from 90 cows at udder quarter level and cow composite level. The milk was analyzed for content of total protein, whey protein, casein, fat, lactose, citric acid and SCC; milk yield was registered. The cows were divided into three groups depending on the SCC of their composite milk. Cows in group 1, cow composite SCC<100 000 cells/ml were assumed to have healthy udders. However instances of increased SCC and decreased milk quality were discovered in one or more udder quarters of approximately 30% of the group. Cows in group 2, cow composite SCC of 100 000 to 300 000 cells/ml, and group 3, cow composite SCC>300 000 cells/ml, were assumed to have affected udders. However, the majority of these cows had one or more udder quarters in which increased SCC and deteriorated milk quality were not detected. Calculations of bulk-tank milk values, when separation of milk from affected udder quarters was performed, indicate that SCC changes to a much greater degree compared to the other milk components. These results show that milk from affected udder quarters suffers compositional changes, but calculations of simulated separation indicate that the compositional changes in bulk-tank milk are small. The effect of separation of milk from individual udder quarters on bulk-tank milk needs to be further studied.
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| 5. |
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| 6. |
- Lundesjö Ahnström, Maria, et al.
(author)
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Influence of carcass suspension on meat quality of Charolais heifers from two sustainable feeding regimes
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 906-913
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Journal article (peer-reviewed)abstract
- This study investigated the effects of pelvic suspension on the meat quality of M. longissimus dorsi, M. semimembranosus and M. adductor from 35 heifers with at least 75% Charolais breeding. Two-thirds of the heifers were slaughtered directly from pasture at 18 months of age and one-third was finished indoors and slaughtered at 22 months. After slaughter and electrical stimulation one side of each carcass was re-suspended by either the achilles tendon or the pelvic bone. Longissimus muscles were aged 7 or 14 days and were then evaluated for drip loss, colour, shear force and sensory analysis. As compared to 18-month-old heifers, 22-month-old heifers were heavier, more muscular and fatter (P < 0.05). Intramuscular fat content increased with slaughter age (P < 0.003). Pelvic suspension reduced longissimus peak force values, total energy, pH and thawing losses (P < 0.05) in heifers slaughtered at 18 months. Semimembranosus showed the largest response to pelvic suspension with significantly lower peak force and total energy values. Finishing for 4 months did not affect longissimus shear forces. Achilles-suspended samples had lower shear force values after 14 v. 7 days of ageing. Pelvic-suspended samples aged 7 days were, however, just as tender as those aged 14 days. Sensory analysis of longissimus samples aged 14 days showed that samples from pelvic-suspended sides had higher tenderness, lower bite resistance, more meaty taste and less visible marbling compared with samples from achilles-suspended carcasses.
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| 7. |
- Lundström, Kerstin
(author)
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Pig meat quality from entire males
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1497-1507
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Journal article (peer-reviewed)abstract
- This paper constitutes an updated review of the production and meat quality aspects of rearing entire male pigs. Since a major obstacle in rearing entire males is the incidence of boar taint, possible methods for detection are also summarised. Safe and fast methods for detection of boar taint would be valuable in avoiding complaints from consumers. Pig meat quality is determined by many aspects, among which odour and taste are the most important attributes. Odour may be negatively affected by the presence of a pheromonal steroid, androstenone, and a fermentation product Of L-tryptophan, skatole. Male pigs are surgically castrated in many countries to minimise the risk of accumulation of high levels of androstenone and skatole. Raising entire male pigs is more profitable because they have superior production characteristics and improved meat quality due to leaner carcasses and higher protein content, as compared to castrated pigs. Furthermore, surgical castration is negative from an animal welfare point of view. In most studies, no differences in sensory quality have been found between lean meat from entire male pigs with low levels of androstenone and skatole and pork from castrates and females. The question that remains is: which substances are responsible for boar taint besides androstenone and skatole and whether they need to be considered? The threshold values used for androstenone and skatole might also be too high for highly sensitive persons. Recent research shows that a human odorant receptor, ORD7D4, is involved in sensitivity to androstenone. If the ORD7D4 genotypes of consumer and expert panels are known, this might facilitate consumer studies in the future. There is still a great need for rapid on/at-line detection methods in abattoirs for identifying carcasses with unacceptable levels of boar taint compounds. Several emerging rapid technologies with a potential for boar taint detection have been investigated. They represent various measurement principles such as chemical sensor arrays (electronic noses), mass-spectrometry fingerprinting, ultra-fast gas chromatography, gas-phase spectrometry and biosensors. An industrial detection method should allow 100% correct classification of both acceptable and not-acceptable samples with regard to boar taint sorting criteria. There are, however, still too high a percentage of false negatives ranging from 5% to 20%. In addition, these methods do not yet seem to fulfil the industrial specifications with regard to cost efficiency, simplicity and analysis time. There is still no dedicated measurement technology available for on/at-line detection of boar-tainted carcasses that measures both androstenone and skatole.
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| 8. |
- Lundström, Kerstin
(author)
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Practice on castration of piglets in Europe
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1480-1487
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Journal article (peer-reviewed)abstract
- PIGCAS (Attitudes, practices and state of the art regarding piglet castration in Europe) is to our knowledge the first project that has focused on castration practice across European countries (European Union minus Bulgaria, Malta and Romania, plus Norway and Switzerland). About 250 million pigs are slaughtered in Europe each year. Of the 125 million male pigs, approximately 20% are left entire, less than 3% are castrated with anaesthesia and the rest is castrated without anaesthesia. The study identified large variations in castration procedures, both within and between countries. In females, castration is very rare, but is practiced without anaesthesia in special breeds/production systems in some of the southern countries
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| 9. |
- Nordquist, Lina, 1977-, et al.
(author)
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Improvement of insulin response in the streptozotocin model of insulin-dependent diabetes mellitus. : Insulin response with and without a long-acting insulin treatment
- 2009
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In: Animal. - : Cambridge university press. - 1751-7311 .- 1751-732X. ; 3:5, s. 685-689
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Journal article (peer-reviewed)abstract
- Streptozotocin-induced diabetes mellitus (STZ-DM) in rats is a model of type 1 diabetes, which is commonly used to study diabetes, but differs from human diabetic pathophysiology in its insulin resistance, An STZ-DM rat can be administered five times the dose of insulin compared to that of a diabetic patient. Thus, attaining normoglycaemia in STZ-DM rats with insulin injections is complicated, and it involves an obvious risk of overdosing before getting a response. This study was designed to investigate whether suboptimal treatment with long-acting insulin restores insulin sensitivity in the STZ-DM rat, and thus an approach to more closely mimic the human condition. Male Sprague-Dawley rats were made diabetic by means of a single intravenous injection of STZ (55 mg/kg body weight (BW)), resulting in an increase in blood glucose (BG) from 6.5 +/- 0.2 to 22.5 +/- 1.0 mmol/l (P <= 0.05) within 24h. After treating the STZ-DM rats with vehicle for 14 days, BG was 26.1 +/- 1.1 mmol/l, and the response to a single injection of fast-acting insulin (Humalog, 5 IE/kg BW) was a 23% reduction in BG. Thereafter, the rats were treated daily with a suboptimal dose of long-acting insulin for a total of 7 days (Insulatard, 5 IE/kg per day), which resulted in a BG level of 19.4 +/- 2.7. The response to fast-acting insulin after the suboptimal treatment was a 61% reduction in BG. Thereafter, the animals were vehicle-treated for another 7 days, which resulted in a response to fast-acting insulin similar to the initial values (-34%). Furthermore, the group treated with suboptimal doses of long-acting insulin had a longer duration of the reduction in BG (150 min, as opposed to 90 min in the vehicle-treated groups). We conclude that the development of a decreased insulin response occurs rapidly within the first 2 weeks after the onset of diabetes in STZ-DM rats. This leads to a brief and significantly reduced decrease in BG when tast-acting insulin is administered, The insulin response is increased by treatment with suboptimal doses of long-acting insulin, but rapidly decreases again when treatment is withdrawn. Regular administration of suboptimal insulin doses may provide an approach to eliminate the effects of a lowered insulin response.
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| 10. |
- Telezhenko, Evgenij
(author)
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Measurement of spatial gait parameters from footprints of dairy cows
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1746-1753
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Journal article (peer-reviewed)abstract
- The variability in dairy cow gait characteristics, determined by measurements of footprints (trackway measurements), was analysed. Seven gait parameters were determined from 32 non-lame dairy cows during free-speed walking on a slatted concrete walkway. The footprints were revealed by application of a thin lime powder-slurry layer to the walkway surface. The cows were observed on two test occasions with a 3-week interval, with measurements from four consecutive strides used within each test session. The variance components for cow, test and cow–test interaction were estimated by a residual (restricted) maximum likelihood method. The percentage of each variance component was calculated to assess the relative impact of each factor on total variance. Between-test variation was generally low, suggesting that cows maintain the same average gait pattern, at least over a 3-week period. The proportion of within-test variation was considerable for most trackway measurements. Stride length, step angle, step width and tracking (overlap) showed low to moderate within-test variation (12% to 27%), whereas for mediolateral displacement of rear feet and step length it was rather high (54% and 62%, respectively). Within-test variation in step asymmetry was very high (77%), suggesting the occurrence of natural, non-systematic changes in inter-limb coordination in non-lame cows. For better understanding the gait pattern in non-lame cows, linear associations between the trackway measurements and with body size were assessed. It was concluded that trackway measurements were able to describe the gait pattern in walking cows under dairy farm conditions. However, considering the relatively high within-test variation in gait, several strides should be used to obtain a representative gait pattern
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| 11. |
- Zamaratskaia, Galia
(author)
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Biochemical, nutritional and genetic effects on boar taint in entire male pigs
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1508-1521
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Research review (peer-reviewed)abstract
- Pork odour is to a great extent affected by the presence of malodorous compounds, mainly androstenone and skatole. The present review outlines the current state of knowledge about factors involved in the regulation of androstenone and skatole in entire male pigs. Androstenone is a pheromonal steroid synthesised in the testes and metabolised in the liver Part of androstenone accumulates in adipose tissue causing a urine-like odour Skatole is produced in the large intestine by bacterial degradation of tryptophan and metabolised by hepatic cytochrome P450 enzymes and sulphotransferase. The un-metabolised part accumulates in adipose tissue, causing faecal-like odour Androstenone levels are mostly determined by genetic factors and stage of puberty, whereas skatole levels in addition to genetic background and hormonal status of the pigs are also controlled by nutritional and environmental factors. To reduce the risk of tainted carcasses entering the market, male pigs are surgically castrated in many countries. However, entire males compared to castrates have superior production characteristics: higher growth rate, better feed efficiency and leaner carcasses. Additionally, animal welfare aspects are currently of particular importance in light of increasing consumers' concerns. Nutrition, hormonal status, genetic influence on boar taint compounds and the methods to develop genetic markers are discussed. Boar taint due to high levels of skatole and androstenone is moderately heritable and not all market weight entire males have boar taint it should thus be possible to select for pigs that do not have boar taint. In these studies, it is critical to assess the steroidogenic potential of the pigs in order to separate late-maturing pigs from those with a low genetic potential for boar taint. A number of candidate genes for boar taint have been identified and work is continuing to develop genetic markers for low boar taint More research is needed to clarify the factors involved in the development of boar taint and to develop additional methods to prevent the accumulation of high concentrations of skatole and androstenone in fat. This review proposes those areas requiring further research.
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| 12. |
- Zamaratskaia, Galia, et al.
(author)
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Modulation of porcine cytochrome P450 enzyme activities by surgical castration and immunocastration
- 2009
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In: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1124-1132
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Journal article (peer-reviewed)abstract
- The present study aimed to evaluate some cytochrome P450 metabolic enzyme activities in hepatic microsomes prepared from entire male pigs (uncastrated pigs), surgically castrated pigs and pigs immunized against gonadotropin-releasing hormone (immunocastrated pigs). The activities of the following enzymes were measured: ethoxyresorufin O-deethylase (EROD, CYP1A1/1A2), methoxyresorufin O-deethylase (MROD, CYP1A2), pentoxyresorufin O-depentylase (PROD, CYP2B), coumarin hydroxylase (COH, CYP2A) and p-nitrophenol hydroxylase (PNPH, CYP2A/2E1). The total cytochrome P450 contents were not affected by either surgical or immunocastration. Hepatic microsomal activities for EROD, PROD, COH and PNPH were lower in entire male pigs compared with surgically castrated and immunocastrated pigs (P < 0.05). Surgically and immunocastrated male pigs were similar with respect to EROD, MROD, PROD and COH activities (P > 0.05), whereas surgically castrated pigs exhibited lower PNPH activity compared with immunocastrated pigs (P = 0.029). The effect of different concentrations of testicular steroids testosterone, 17 beta-estradiol, free estrone and androstenone - on enzyme activities was evaluated by in vitro microsomal study. Testosterone at the concentration of 8 pmol/ml inhibited EROD activities and estradiol-17 beta at the concentration of 1.8 pmol/ml inhibited PROD activities in hepatic microsomes from surgically castrated pigs. The highest concentration of androstenone (7520 pmol/ml) inhibited COH activities, whereas a 42-fold lower concentration of androstenone (180 pmol/ml) stimulated COH activities in surgically castrated pigs. Both free estrone (3.5 pmol/ml) and androstenone (55 pmol/ml) inhibited EROD activities in microsomes from entire male pigs. Stimulation of COH activities by the highest dose of free estrone (18 pmol/ml) was recorded in microsomes from entire male pigs. However, these effects of steroids were not concentration-dependent and the maximum extent did not exceed +/- 15% variation compared with the controls. There was no inhibition of PNPH activities in the hepatic microsomes from either entire or castrated pigs. In conclusion, we showed that EROD, PROD, COH and PNPH activities were lower in entire male pigs compared with those in surgically and immunocastrated pigs. Direct inhibition by the testicular steroids - testosterone, 17 beta-estradiol, free estrone and androstenone - was not the primary cause of the reduced enzyme activities.
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| 13. |
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| 14. |
- Eriksson, S., et al.
(author)
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Genetic analysis of insect bite hypersensitivity (summer eczema) in Icelandic horses
- 2008
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In: Animal. - 1751-7311. ; 2:3, s. 360-365
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Journal article (peer-reviewed)abstract
- There is a lack of knowledge about the genetic background of eczema due to insect bite hypersensitivity, also called summer eczema, in horses. The condition is known in several horse breeds and countries and it causes reduced welfare of the horse and economic losses to the owner The aim of this study was to estimate genetic parameters for summer eczema in Swedish-born Icelandic horses. A questionnaire was sent to owners of horses sired by stallions with more than 50 offspring born in Sweden between 1991 and 2001. Variance components of summer eczema classified as healthy, mild, moderate or severe were estimated using the threshold methodology with sire models. In addition, summer eczema was analysed as a binary trait (healthy v. affected). The analyses included 1250 horses sired by 33 stallions. The prevalence of summer eczema was 8%, with a range of 0% to 30% in different paternal half-sib groups. Offspring of dams suffering from eczema had a higher risk of developing eczema. The heritability for severity of summer eczema was estimated at 0.3 (s.d. < 0.2) with a threshold sire model. In contrast to the age of the horse, different geographic areas and gender were significantly associated with severity of the eczema. We conclude that genetic selection could decrease the prevalence of summer eczema among Swedish-born Icelandic horses. The amount and quality of data are, however crucial for the possibility to introduce a genetic evaluation of summer eczema. The symptoms should be classified in several classes according to severity, and this classification could be made by the horse owner.
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