Direct and Maternal Genetic Trends for Some Productive and Reproductive Traits in Egyptian Buffaloes

Abstract

This study was done to determine the direct and maternal genetic and phenotypic trends for productive traits such as first lactation milk yield (FLMY, kg), first lactation period (FLP, d) and first lactation daily milk (FLDM, kg), and reproductive traits such as age at first calving (AFC, mo), First days open (FDO, d) and first calving interval (FCI, d). Data were collected over consecutive 25 years (1991 to 2015) of 1104 first lactation of 135 sires and 482 dams maintained at Mahallet Mousa farms of Animal Production Research Institute. Data were analyzed by Animal model to determine genetic parameters for studied traits. Means of FLMY, FLP, FLDM, AFC, FDO and FCI were 1546.5kg, 189d, 7.9kg, 37.9mo, 120.8d and 428d, respectively. The direct heritability (h2a) for same traits were 0.25, 0.18, 0.24, 0.45, 0.18 and 0.19, respectively. Corresponding maternal heritability (h2m) for mentioned traits was 0.12, 0.19, 0.22, 0.25, 0.12 and 0.12, respectively. Genetic correlations (rg) among studied traits were varied between -0.19 to 0.38. Accuracy of predicted breeding value varied between 69 to 94, 0.37 to 94 and 42 to 91% for FLMY, FLP, FLDM, AFC, FDO and FCI of sires, cows and dams, respectively that revealed the genetic improvement could be actualized through each of cows or sires or dams. Additive and maternal genetic, permanent environmental and phenotypic trends were not significant for all studied traits. It indicated that it is important to set up a plan to improve genetic and environmental conditions thus, increasing productivity and realization of high profitability.

Genetic Parameters for Some Reproductive Traits in Egyptian Buffaloes

“…This may arise from that AFC depends on puberty reaching and can be influenced by a lesser degree of management practices. The obtained results in this study fall within the range of those reported by other investigators as ranged from 0.11 to 0.45 for AFC (El-Bramony, 2011, andEl-Naser, 2020), from zero to 0.06 for GL on different buffalo breeds (Khalil et al, 1991 andThevamanoharan et al, 2002), from zero to 0.18 for DO (Metry et al,1994 andAbo-Gamil et al, 2017) and from zero to 0.17 for CI (Cockrill, 1974 andAbo-Gamil et al, 2017). Genetic and phenotypic correlations among studied traits are given in Table 4.…”

“…In contrast, lower than estimated by Ryan et al (2007) of 340 days on African buffalo. Means reported herein for DO and CI fall within the ranges of those obtained for the Egyptian buffaloes as ranged from 120.8 to 250.9 days and from 428 to 539.9 days, respectively (El-Naser, 2020 andAfifi, et al, 1992). This study reflected variation coefficients ranged from 6.98 % to 19.67% except for DO had a higher C.V % of 57.67%, that indicating a large variation among individual buffaloes which can be a good opportunity for this trait to be improved.…”

GENETIC Parameters for some Productive and Reproductive Traits for First Lactation in Egyptian Buffalo

“…There were positive genetic correlations among the reproductive traits in this study that ranged from 0.04 (GL-DO) to 0.99 (CI-DO), which revealed that buffalo cows reproduced earlier tended to have shorter GL, CI, DO (Table 4). These results were comparable with the finding of others (Gutierrez et al, 2007;Eaglen et al, 2012;Brzáková et al, 2019;Lopez et al, 2019;Setiaji and Oikawa, 2019;Abu El-Naser, 2020).…”

Estimation of direct and maternal covariance along with genetic and phenotypic trends of reproduction traits in Murrah buffalo

“…Comparing our results with existing literature provides a contextual understanding. Abu El‐Naser (2020) conducted a study on Egyptian buffaloes, reporting a lower additive genetic variance ($$$ {\sigma}_{\mathrm{a}}^2 $$$ = 465.45) but a higher heritability ( h 2 = 0.19) compared with our findings. Kumar and Mandal (2021) in Jersey crossbred cattle observed higher values for both additive genetic variance ($$$ {\sigma}_{\mathrm{a}}^2 $$$ = 2340.744 to 3835.815) and heritability ( h 2 = 0.16 to 0.25), emphasizing breed‐specific variations.…”