Genetic Study of Fertility Traits and Productive in a Local Born Friesian Cattle in Egypt

Abstract

A total 1481 first lactation records of local born Friesian heifers were collected from Sakha Farm, Animal Production Research Institue, Ministry of Agriculture, during the period from 1980 to 1993. A linear mixed model was used to study the fixed effects of month and year of calving, age at first calving as a covariate and the random effect of sire on productive traits (i.e., 90 day milk yield (90dMY), 305 day milk yield (305dMY), total milk yield (TMY), lactation period (LP) and dry period (DP)). The effects of the same factors on reproductive traits (i.e., days open (DO) and calving interval (CI)) were also studied. Least squares means of 90 dMY, 305 dMY, TMY, LP, DP, DO and CI were 959 kg, 3252 kg, 3709 kg, 367 d, 65 d, 145d and 426d, respectively. A least squares analysis of variance showed significant effect of month of calving on 90 dMY, 305 dMY, TMY and LP (p<0.05 or p<0.01). Year of calving had a significant effect on all traits studied (p<0.05 or p<0.01). Including age at first calving (AFC) as a polynomial regression of the second degree in the model yielded significant (p<0.05 or p<0.01) partial linear regression coefficients of 90 dMY, 305dMY, TMY and DP on AFC while the quadratic term was significantly only for 305dMY. Sire of the heifers had a significant effect on all productive traits. Heritability estimates for 90dMY, 305dMY, TMY, LP, DP, DO and CI were 0.30 ± 0.08, 0.30 ± 0.08, 0.15 ± 0.06, 0.10±0.06, 0.09±0.06, 0.05±0.06, 0.05±0.06, respectively. In addition, genetic and phenotypic correlations between different traits studied are calculated and tabulated. Negative genetic correlations between each of DP, DO and CI and 90dMY, 305dMY and TMY concluded that selection against dry period and days open will increase milk yield. Therefore, a reduction of DP and DO are the desirable goal of dairymen.

Genetic Analysis of Some Productive and Reproductive Traits of First Lactation of Friesian Cattle Raised in Egypt

“…Overall means, standard deviations (SD) and coefficients of variation (CV %) are shown in Table 1. The present overall mean of TMY was 5387 kg similar results were (5283 kg) found by Tag El-Dein (1997) working with another set of Friesian cows at the same farm and much higher than the published estimates on Friesian cattle in Egypt 2655 kg by Oudah and Zainab (2010), 3936 kg by El-Awady and Oudah (2011) and 2871 kg by Khattab and Sultan, 1990) and higher than those obtained by Khattab and Atil (1999) and Oudah et al (2000) being 3709 and 3475 kg, respectively. And with 3710 kg that obtained by Tadesse et al (2010) for Friesian in Ethiopia, 5905 kg that found by Ajili et al (2007) in Tunis, 4489 kg that reported by Ahmed et al (1997) in Libya.…”

Estimation of Genetic and Phenotypic Parameters for Some Milk Traits on Egyptian, Friesian and their Crosses Cows

“…Year of calving had a significant effect on 305 d MY and LP for all three genetic group (P < 0.01, Table 3). Similar results are reported by Khattab and Sultan (1991), Khattab and Atil (1999), Yener et al (2006), EL-Shabory (2009) and El-Awady et al (2014). Change in milk yield and lactation period from year to another can be attributed to change in herd size, age of animals and improved management practiced introduced from year to another and phenotypic trends.…”

“…Sire of the cow and cow within sire had a significant effect on 305 d MY and LP for the three genetic group studied (P < 0.01, Table 3). The present results are in agreement with those obtained by Khattab and Sultan (1991), Khattab and Atil (1999), Yener et al (2006) and El-Awady et al (2014), working on different breeds of dairy cattle. The present results indicated that the possibility of genetic improvement of milk traits through sire and dam selection.…”

“…The present results indicated that cows had high milk yield also longer lactation period. Similar results are reported by Khattab and Sultan (1991), Khattab and Atil (1999), Hussein (2004), El-Shabory (2009 and El-Awady et al (2014).…”

Variances of Direct and Maternal Genetic Effects for Milk Yield and Its Composition in a Herd of Friesian Cows in Egypt

“…Table 1 shows the data structure considered in the analysis. Khattab and Atil (1999) working on another set of Friesian cows in Egypt, found that means of 305 d MY and LP were 3709 kg and 367 d, respectively. Overall mean of F % was similar to that reported by Albuquerque et al (1998) (3.7) working on Holstein Friesian.…”