Estimates of phenotypic and genetic parameters for birth weight of Brown Swiss calves in Turkey using an animal model

Abstract

A study was conducted to assess the influence of genetic and environmental factors on Brown Swiss calf birth weight, and to estimate variance components, genetic parameters, and breeding values. Data were collected on 1,761 Brown Swiss calves born from 1990 to 2005 in the Konuklar State Farm in Turkey. Mean birth weight for all calves was 39.3 ± 0.09 kg. Least squares mean birth weights for male and female Brown Swiss calves were 40.3 ± 0.02 and 39.0 ± 0.02 kg, respectively. Variance components, genetic parameters, and breeding values for birth weight in Brown Swiss calves were estimated by restricted error maximum likelihood (REML)-best linear unbiased prediction(BLUP) procedures using an MTDFREML (multiple trait derivative free restricted maximum likelihood) program employing an animal model. Direct heritability (h(d)(2)), maternal heritability (h(m)(2)), total heritability (h(T)(2)), r(am) and c(am) estimates were 0.12, 0.09, 0.23, -0.58, and -0.06, respectively. The estimated maternal permanent environmental variance expressed as a proportion of the phenotypic variance (c(2)) was 0.05. Breeding values were estimated for the trait and used to evaluate genetic trends across the time period investigated. The genetic trend linear regression was not different from zero. No genetic trend for birth weight was expected, since there had been no direct selection pressure on the trait. Absence of a trend confirms that there was no change due to selection pressure on correlated traits. Genetic and environmental parameter estimates were similar to literature values indicating that effective selection methods used in more developed improvement programs would be effective in Turkey as well.

The application of six different models to estimate the genetic parameters, variance components and breeding values for birth weight of Holstein calves

“…In the study of Demeke and Neser Schoeman (2003), a small (yet non-zero) estimate was also reported for maternal heritability for BW. This finding was similar to those in the study of Sahin et al (2012). Pico (2004) and Plasse et al (2002aPlasse et al ( , 2002b previously informed m 2 for BW values of 0.11, 0.08 and 0.07 in Brahman cattle; these values are lower than the ones identified in the current study.…”

“…The r am was negative and high for models 4 (−0.76 ± 0.027) and 6 (−0.67 ± 0.115). Similarly, genetic correlations estimated by Sahin et al (2012) for Brown Swiss calves, Karabulut et al (2012) for Holstein calves were negative and ranged from −0.58 to −1.00. However, compared to the results of the current study, lower r am estimates (−0.35 to −0.37) have been informed for Brahman cattle (Plasse et al 2002a;Pico 2004), while similar estimates have been noticed for Nellore cattle (−0.72, Eler et al 1995) and Boran cattle (−0.55, Haile-Mariam & Kassa-Mersha 1995).…”

“…Higher total heritability estimates varying between 0.37 and 0.62 were reported by Abera et al (2011) for Zebu and their crosses Jersey and Holstein cattle. Furthermore, Tilki et al (2008) and Sahin et al (2012) also determined higher h 2 T for Brown Swiss cattle. Estimates of total heritability represent a useful mean for estimating response to selection based on the phenotypic value.…”

“…Model 1, fitting animal as the only random effect, produced considerably higher estimates for s 2 a and h 2 d than other models. Likewise, higher heritability estimates for BW from model one have been informed for different cattle breeds (Abera et al 2011;Sahin et al 2012).…”

Genetic and Phenolytic Parameters for Early Growth Traits on Egyption Baladi Calves

“…The genetic light of birth weight in farm animals indicated that it consider as the most important character influences the lifetime yields of the animal (Karakus et al, 2010). On the basis of this knowledge genetic improvement programs must be introduce the birth weight for its easily measur in one hand and its correlation with of other beef performance traits in the other hand (Sahin et al, 2012).…”