| 1. |
- Braam, Åsa, et al.
(författare)
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Genetic variation in durability of Swedish Warmblood horses using competition results
- 2011
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 142, s. 181-187
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate the possibilities of using number of years in competition as a measure of durability in the genetic evaluation of Swedish Warmblood horses. Competition results recorded between 1971 and 2008 in the disciplines dressage, show jumping and eventing were used to estimate genetic parameters for number of years in competition. Only male horses not used in breeding born between 1967 and 1991 were included in the study (17,962 horses). The study showed that horses with placings in more than one discipline at an early age had the longest competition career. This result suggests that these horses are talented for sports and possibly also that there is a positive effect of all-round training of young horses on their durability. For estimation of genetic parameters for number of years in competition different linear mixed animal models were compared. Depending on the model and transformation the heritability for total number of years in competition varied between 0.07 and 0.17. The lower values were obtained when adjustments in the model were made for age at first placing in competition. Higher heritabilities were obtained for competition years in show jumping and lower for eventing. Performance traits scored at young horse tests and as points in competition (lifetime and for young horses) showed positive genetic correlations with total number of years in competition. These results indicate that years in competition represent both the durability of the horses and their talents for performance. It is suggested that number of years in competition may be used for genetic evaluation of durability.
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| 2. |
- Corrales, Roldan, et al.
(författare)
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Birth weight, reproduction traits and effects of inbreeding in Nicaraguan Reyna Creole cattle
- 2011
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Ingår i: Tropical Animal Health and Production. - : Springer Science and Business Media LLC. - 0049-4747 .- 1573-7438. ; 43, s. 1137-1143
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Tidskriftsartikel (refereegranskat)abstract
- Reyna Creole cattle in Nicaragua comprise about 650 purebred animals, and the breed has been shown to have a high level of inbreeding. To characterize the breed, as basis for a conservation program, information from two herds on birth weight (BW, n = 1097), age at first calving (AFC, n = 449) and calving interval (CI, n = 1,347) was analysed. Overall averages were 27.8 kg for BW, 37.4 months for AFC and 424 days for CI. Large differences between the herds were observed for all traits. Thus, there would be opportunities for management interventions to improve reproduction results. The heritability for BW was 0.34. For CI, the heritability of 0.20 and the additive genetic standard deviation of 36 days were comparatively high values. No genetic variation was found in AFC. Estimated inbreeding effects were associated with large standard errors due to the small size of the data and incompleteness of pedigrees. Nevertheless, significant effects were shown of dam inbreeding level on all traits. For each percentage of increased inbreeding, BW decreased by 0.06 kg, AFC increased by 3.5 days and CI increased by 1.4 days. The effects of the inbreeding level of the individual itself were not significant. The relatively good reproduction traits of Reyna Creole cattle shown in this study, despite high inbreeding levels, will be supplemented with a characterization of milk production traits.
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| 3. |
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| 4. |
- Fikse, Freddy, et al.
(författare)
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Genetic variation in wholesale carcass cuts predicted from digital images in cattle
- 2011
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 5, s. 1720-1727
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to quantify the genetic variation in carcass cuts predicted using digital image analysis in commercial cross-bred cattle. The data set comprised 38 404 steers and 14 318 heifers from commercial Irish herds. The traits investigated included the weights of lower value cuts (LVC), medium value cuts (MVC), high value cuts (HVC), very high value cuts (VHVC) and total meat weight. In addition, the weights of total fat and total bones were available on the steers. Heritability of carcass cut weights, within gender, was estimated using an animal linear model, whereas genetic and phenotypic correlations among cuts were estimated using a sire linear model. Carcass weight was included as a covariate in all models. In the steers, heritability ranged from 0.13 (s.e. = 50.02) for VHVC to 0.49 (s.e. = 50.03) for total bone weight, and in the heifers heritability ranged from 0.15 (s.e. = 50.04) for MVC to 0.72 (s.e. = 50.06) for total meat weight. The coefficient of genetic variation for the different cuts varied from 1.4% to 3.6%. Genetic correlations between the different cut weights were all positive and ranged from 0.45 (s.e. = 50.08) to 0.89 (s.e. = 50.03) in the steers, and from 0.47 (s.e. = 50.14) to 0.82 (s.e. = 50.06) in the heifers. Genetic correlations between the wholesale cut weights and carcass conformation ranged from 0.32 (s.e. = 50.06) to 0.45 (s.e. = 50.07) in the steers, and from 0.10 (s.e. = 50.12) to 0.38 (s.e. = 50.09) in the heifers. Genetic correlations between the same wholesale cut traits in steers and heifers ranged from 0.54 (s.e. = 50.14) for MVC to 0.79 (s.e. = 50.06) for total meat weight; genetic correlations between carcass weight and carcass classification for conformation and fat score in both genders varied from 0.80 to 0.87. The existence of genetic variation in carcass cut traits, coupled with the routine availability of predicted cut weights from digital image analysis, clearly shows the potential to genetically improve carcass value.
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| 5. |
- Jönsson, Lina, et al.
(författare)
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Equine hospital data as a source for study of prevalence and heritability of osteochondrosis and palmar/plantar osseous fragments of Swedish Warmblood horses
- 2011
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 43, s. 695-700
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Tidskriftsartikel (refereegranskat)abstract
- Conclusions and potential relevance: Obtained prevalences and heritabilities were in accordance with other studies, supporting the hypothesis that data regularly obtained from equine hospitals may be a valuable source in studies of inherited disorders such as OC and POF. There is a need for more standardised documentation of diagnoses and consistent recording of identity of examined horses using passports or breed databases. Compilation of results from major clinics is desired in order to cover most progenies of stallions used in a region or nation.
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| 6. |
- Näsholm, Anna
(författare)
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Characteristics and utilization of sheep pelts
- 2011
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Ingår i: Small Ruminant Research. - : Elsevier BV. - 0921-4488. ; 101, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- In the present work the production and quality of sheep pelts is reviewed with emphasis on three breeds, the Karakul, the Swedish Gotland and the Icelandic sheep, as well as with some information from sheep breeds from Australia and New Zealand. Sheep pelts are a by-product from meat and wool production in all breeds world-wide except for the Karakul and Gotland breeds. Special pelt products include pelt skins for fur-clothing, double-face or suede shearling skins for reverse fur clothing, wool-skins for rugs and car seat covers and medical sheep skins for hospital use. Selection for pelt traits in Karakul and Gotland sheep is based on subjective scoring of important traits. Genetic studies on pelt quality have reported medium high and high heritability of pelt traits indicating good possibilities of genetic improvement. Several important traits have an intermediate optimum and disassortative mating has been suggested as the most efficient way of improvement. The future prospects of sheep pelt production are discussed. (C) 2011 Elsevier B.V. All rights reserved.
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