Epigenetics TREND for some Productive and Reproductive Traits of Friesian Cattle Raised in Egypt

Abstract

The objectives of this study were to estimate the genetic parameters and Epigenetics TREND (EP) of milk traits of herd of Friesian in Egypt. The studied traits were 305 day milk yield (305d-MY, kg),total milk yield (TMY, kg), Lactation period (LP, day), days open (DO) and number of services per conception (NSC, services).The data included 1794 records of 704 cows daughters of 86 bulls and 439 damduring the years 2007to 2016 were collected from Alkarda farm (Government farm) located in Kafr El-Sheikh, Egypt. Single-Trait animal model was used to estimate genetic parameter; overall means of 305-dayMY, TMY, LP, DO and NCS were 2935Kg, 3320 Kg , 310 day, 151 day and 1.7 services, respectively, Additive heritability (h a) estimated for 305d-MY, TMY, LP DO and NSC were 0.34, 0.31, 0.29, 0.06 and 0.26,respectively. While maternal heritability (h m) were 0.03, 0.07, 0.05, 0.01 and 0.002, respectively , The environmental impact of the permanent lower corresponding values were 0.0031, 0.0027, 0.0037, 0.0062 and 0.0038, respectively.Indicating that the effect of animals' genetic performance is affected by the surrounding environmental conditions where full care through the mother leads to improvement of the studied traits.The genetic and phenotypic correlations of most of the studied traits were highly significant (p <0.001) and ranged from-0.22 to 0.46for geneticcorrelationbetween traits whilephenotypic correlation ranged from-0.11 to 0.65.Genetic trends were positive for all studied traits except for days open and NSC. Range of breeding value (BV)for all studied traits of cows (