Genetic and Phenotypic Association between Productive and Reproductive Traits in Friesian Cows In Egypt

Abstract

Genetic parameters for Friesian cows were estimated from 9155 lactation records for 3625 cows sired by 182 bulls covered 34 years in two herds (Sakha and El-Karada), belongs to the Animal Production Research Institute, Ministry of Agriculture, Egypt. Multi-trait repeated animal model was employed using the REML procedure to estimate (co)variance components of productive (305-day milk yield-M305 and lactation period-LP) and reproductive traits (number of services per conception-NSC, calving to first service interval-CFS and days open-DO), There is sufficient genetic variation in productive (from 9.5 to 17.1%) and reproductive traits (from 3.9 to 10.3 %). Heritability estimates for M305 and LP traits were 0.204 and 0.110, however, reproduction traits were ranged from 0.010 to 0.044. Genetic correlation between M305 and LP was high (>0.94). Among reproductive traits, absolute genetic correlations were also high (>0.85). Genetic correlations between reproductive and productive traits were high (>0.99). The annual genetic changes were positive for M305, LP, CFS and DO (9.07 kg/yr., 0.30, 0.07 and 0.24 d/yr., respectively), however it was -0.003 number/yr for NSC. The annual phenotypic changes were positive for M305, CFS and DO (12.4 kg/yr., 0.029 and 0.829d/yr., respectively), however it were negative for LP and NSC (-0.265 d/yr. and -0.002 number /yr.).

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

“…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.…”

“…The unadjusted means, standard deviations (SD) and coefficients of variations for studied productive and reproductive traits are presented in Table (2). 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.…”

“…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). On the other hand, lower and similar heritability estimates for LP were 0.029, 0.08 and 0.07 as reported by Salem and Hammoud (2016), Sanad (2016) and Abosaq et al (2017).…”

“…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). The estimation of genetic and phenotypic parameters for these traits is an important tool to define and evaluate the selection programs (Sanad, 2016).…”

“…Generally, it is necessary to be aware about the environmental variables and other factors affect the performance of dairy cows and farm economy in order to improve its productivity and profitability (Abd-El Rahman et al, 2020 andAbd-El Hamed andKamel, 2021). Thus continuous evaluations of dairy cattle management conditions, environmental parameters, genetic and phenotypic trends, are needed to monitor whether the trends and parameters are desirable for each productive and reproductive trait (Zahed et al, 2020).…”