Genetic Evaluation for Some Productive and Reproductive Traits in Friesian Cows Raised in 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 (h 2) 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.

Evaluation of Some Economical Traits of Commercial Friesian Cows Herd Raised in Egypt

“…In agreement with present results, previous studies concluded significant effects of parity on DO (Faid-Allah, 2015;Rushdi, 2015 andSalem andHammoud, 2016), CI (Sanad, 2016), NSC (Salem andHammoud, 2016 andHassanane, 2017) and AFC (Sanad and Hassanane, 2017). Contradictory to present results, Faid-Allah (2015) and Abosaq et al (2017) indicated that DO increases from the first parity (100.78 and 148.31 d, respectively) to the fifth parity (186.51 and 180.1 d, respectively).…”

“…Also, the present mean of CI (377.4 d) was shorter than that of 414.43, 472.0, 433.2 and 427.72 days as presented by Abosaq et al (2017), Farrag et al (2017), Zahed et al (2019) and Habib et al (2020), respectively. Mean of NSC (1.99) was comparable to that values given by Salem and Hammoud (2016)(2.0), Sanad and Hassanane (2017)(1.93) and Abosaq et al (2017)(2.16), while it was lower than the values estimated by Habib et al (2020)(3.0) and Zahed et al (2020)(3.1). Regarding the AFC value (26.97 mo), in present study, it was nearly similar to (27.2 mo) as recorded by Salem and Hammoud (2016).…”

“…Regarding the AFC value (26.97 mo), in present study, it was nearly similar to (27.2 mo) as recorded by Salem and Hammoud (2016). On the other hand, higher AFC values (29.4, 32.5 and 30.9 mo) were obtained by Farrag et al (2017), Sanad and Hassanane (2017) and Almasri et al (2020), respectively.…”

“…Sanad (2016) detected also highly significant effect for season of calving on CI, but the longest CI was in winter (461.0 mo) and the lowest was in autumn (448.9 mo). While, Sanad and Hassanane (2017) found that the NSC in winter (1.91) was higher than in summer (1.75) and spring (1.79). Regarding AFC, present obtained results are in agreement with Sanad and Hassanane (2017) who reported higher AFC in summer (33.74 mo) and lowest value was in winter (32.9 mo) for Friesian cows in Egypt.…”

“…While, Abosaq et al (2017) found that CI slightly decreased from 446.27 to 426.96 d in fifth parity. Moreover, Sanad and Hassanane (2017) found that NSC significantly decreased from first parity (1.97) to the fifth parity (1.71). While, no significant effect of parity on NSC was detected by Salem and Hammoud (2016).…”