Genetic Evaluation for Some Productive and Reproductive Traits in Friesian Cows Raised in Egypt | ||
| Journal of Animal and Poultry Production | ||
| Article 4, Volume 8, Issue 8, August 2017, Pages 227-232 PDF (262.92 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jappmu.2017.45895 | ||
| Authors | ||
| Safaa S. Sanad* 1; M. S. Hassanane2 | ||
| 1Animal Production Research Institute (APRI), Dokki,, Egypt | ||
| 2Cell Biology Department, National Research Center, Dokki, Giza, Egypt | ||
| Abstract | ||
| The objective of this study was to estimate the genetic parameters (heritability, and breeding values) as well as the effect of non-genetic factors such as (abdominal arrangement, season and year of calving also interactions between these factors) for some productive and reproductive traits. From the studied traits: total milk yield (TMY, kg), 305 day milk yield (305d-MY, kg), Lactation period (LP, day) as milk production traits, number of services per conception (NSC, services) and age at first calving (AFC, month) as reproductive traits. A total number of 1876 lactation records of 586 cows (daughters of 374 dams and 58 sires) in Sakha herd, during the period from 2001 to 2015 in dairy Friesian herd in farm Egypt. The analysis was performed using SAS (2003). The model included the random effects of genetic factors (sire effect) and fixed effects (parity, season and year of calving). In addition Single-trait animal models were used to estimate genetic parameters; Animal model was used to estimate heritability and breeding value. 1- Actual means of TMY, 305d-MY, LP, NSC and AFC were 4038.56kg ; 3734.8 kg; 317.8 day; 1.93 and 32.5 month respectively. 2- Heritability (h2) estimated of TMY, 305d-MY, LP, NSC and AFC were 0.17, 0.25, 0.17, 0.06 and 0.36 respectively. 3- Rank correlation (were computed between predicted breeding values) among TMY, 305d-MY LP, NSC and AFC were highly significant effect, the ranged from -0.17 to 0.59 in production traits. 4- Regression coefficients of estimated breeding values of cow on time were negative and no significant for all studied traits 5- The range of breeding value (BV) for cows was high for most of studied traits. The ranges of breeding values of cows for TMY, 305d-MY, LP, NSC and AFC were 2823, 1744, 2848, 0.754 and 7.68 respectively. In conclusion, The difficulty of genetic improvement of NSC by selection due to the low heritability of this trait but can be improved by increasing good care and improving environmental conditions together. Higher ranges of BV for cows for most of studied traits indicate higher genetic variation and higher opportunity for selection of top cows in breeding value, which would result in rapid genetic progress in the future generations. The study recommends that this be confirmed by molecular genetics to detect the location of quantitative traits that affect milk production and selection of the cows carrying these genes. | ||
| Keywords | ||
| productive; reproductive; traits; Genetics; heritability; Friesian; Egypt | ||
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