Genetic and Phenotypic Parameters and Trends for Milk Yield, Service Period and Calving Interval and The Economic Impact of Extending A Calving Interval on-Farm Profitability in Friesian Cows in Egypt

Abstract

Genetic parameters for Friesian cows were estimated from 9155 lactation records for 3635 cows sired by 184 bulls. Multi-trait repeated animal models were employed using the REML procedure to estimate covariance components of total milk yield (TMY), service period (SP) and calving interval (CI). There is sufficient genetic variation (indicated by the coefficient of genetic variation) in total milk yield, service period and calving interval traits (15.6, 3.6 and 3.7%, respectively). Estimates of heritability for TMY, SP and CI traits were 0.170, 0.010 and 0.044, respectively. Permanent environmental variance ratios were 0.162, 0.017 and 0.048 for TMY, SP, and CI, respectively. Genetic correlations among SP and CI traits were high (0.998), however genetic correlations of reproductive with productive traits were unfavorable (0.512-0.661). The results indicated the possibility of continued selection for increased milk production which has deleterious effects on reproductive traits. The annual genetic changes were positive for TMY, SP, and CI (7.76 kg/yr, 0.076, and 0.24 d/yr, respectively). These positive trends indicate that there has been success in choosing better sires.The corresponding annual phenotypic changes for the same traits were positive (13.9 kg/yr, 0.029 and 0.82 d/yr, respectively). Positive annual genetic and phenotypic changes for SP and CI indicated that with improving milk yield the SP and CI will be increased. The financial situation of the farm is affected by the extension of the calving interval. The lower the calving interval, the more profitable the farm becomes, and prolonging this period for one day causes a financial loss for the farm.

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

“…The TMY average of the present study (5778.15 kg) was higher (4227 kg) reported by Abosaq et al (2017), 2939 kg by Shehab El-Din (2020), and 3879 kg by Badr and Amer (2020), while it was lower than the TMY values of 8315 kg stated by Salem and Hammoud (2016), 6173.5 kg by Farrag et al (2017) and 8675 Overall mean of DO (99.56 d) detected in present study was shorter than means detected in different commercial Friesian herds (113.1, 144.49, 174.4, 166.50 and 159 d) obtained by (Salem and Hammoud, 2016;Abosaq et al, 2017;Farrag et al, 2017, Habib et al, 2020and Zahed et al, 2020. 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).…”

“…The heritability estimated for DO in present study (0.100) was in more close to the values of 0.105, 0.11 and 0.19 that recorded by Faid-Allah (2015), Rushdi (2015) and Habib et al (2020), while was higher than those estimated by Salem and Hammoud (2016), Abosaq et al (2017) and Zahed et al (2020) as being 0.028, 0.04 and 0.044, respectively. The CI heritability estimated (0.103) was higher than those noticed by Sanad (2016), Abosaq et al (2017), Zahed et al (2019) and Habib et al (2020) as being 0.07, 0.03, 0.04 and 0.09, respectively. Likewise, the heritability of NSC (0.123) was higher than those presented by Salem and Hammoud (2016), Abosaq et al (2017), Sanad and Hassanane (2017), Habib et al (2020) and Zahed et al (2020)(0.006, 0.03, 0.06, 0.04 and 0.01, respectively).…”

“…Higher heritability estimates for TMY were 0.223, 0.33, 0.32 and 0.28 as detected by Faid-Allah (2015), Sanad (2016), Amer (2020) andKamal El-den et al (2020), respectively. While, lower and closer TMY heritability estimates were reported by Salem and Hammoud (2016), Sanad and Hassanane (2017) and Zahed et al (2019) (0.065, 0.17 and 0.17, respectively). The higher LP heritability estimates for LP were 0.112, 0.17, 0.10, 0.13 and 0.11 as found by Faid-Allah (2015), Sanad and Hassanane (2017), Amer (2020), Kamal El-den et al (2020) and Zahed et al (2020).…”

“…While genetically, the undesirable relationship between the productive and reproductive performance traits should be taken into consideration (Habib et al, 2020). However, the direct measures of fertility and milk yield records can be used to supplement the predictions of genetic merit for fertility (Zahed et al, 2019). Thus the interest has increased for including functional traits and fertility in the breeding goal for populations of dairy cattle (Zahed et al, 2020).…”

Effect of some non-genetic factors on the productivity and profitability of Holstein Friesian dairy cows

“…Furthermore, Mengistu and Wondimagegn[21], Lehmann et al[46], and Kidane et al[47] reported that DO is the part of the CI, and longer DO reduced the farm profitability. Zahed et al[48] concluded that farm profitability increased by shortening CI, and prolonging this period for 1 day causes a financial loss for the dairy farm. This may be due to the increasing value in milk income.…”