scholarly journals Estimation of genetic parameters for milk yield in Murrah buffaloes by Bayesian inference

2010 ◽  
Vol 93 (2) ◽  
pp. 784-791 ◽  
Author(s):  
F.C. Breda ◽  
L.G. Albuquerque ◽  
R.F. Euclydes ◽  
A.B. Bignardi ◽  
F. Baldi ◽  
...  
2014 ◽  
Vol 7 (12) ◽  
pp. 1094-1098 ◽  
Author(s):  
Saroj Kumar Sahoo ◽  
Avtar Singh ◽  
A. K. Gupta ◽  
A. K. Chakravarty ◽  
Manvendra Singh ◽  
...  

Author(s):  
A. Godara ◽  
D. Singh ◽  
S. S. Dhaka

The data pertinent to lactational performance traits on Murrah buffaloes calved during period 1987 to 2002, progeny of 52 sires maintained at Buffalo Research Centre, LLR University of Veterinary and Animal Sciences, Hisar were considered. The estimates of heritability were obtained low to moderate for almost all lactational performance traits. All the first lactation traits viz., AC1, SP, CI, MY, LL, PY, DAPY and MY/LL had moderate to high positive genetic correlations among themselves except PY with CI and DAPY with AC1, which is negative. Age at calving (AC2) had moderate positive genetic correlation with second lactational performance traits like SP, MY, LL, PY, MY/LL and MY/CI and had negative correlations with DAPY and DP. Moreover, third lactational traits like milk yield, LL, PY, DAPY, MY/LL and MY/CI had high positive genetic correlations among themselves. However, age at calving during fourth lactation had positive genetic correlations with all the traits except CI, DAPY and DP which had negative genetic correlations with it. It is inferred that information on sip performance and other relatives coupled with better husbandry practices would be required to bring desirable improvement in these lactational performance traits.


Author(s):  
Ekta Rana ◽  
Ashok Kumar Gupta ◽  
Avtar Singh ◽  
Atish Kumar Chakravarty ◽  
Saleem Yousuf ◽  
...  

Background: The estimates of genetic parameters are useful in determining the appropriate method of selection that could further be implemented in the breed improvement programmes. The present study was, therefore, conducted to estimate the genetic parameters (heritability, genetic and phenotypic correlations) for monthly test day (TD) milk yields, peak yield (PY) and first lactation 305 days milk yield (FL305DMY) in Murrah buffaloes.Methods: Paternal half-sib correlation method was carried out by least-squares maximum likelihood programme to estimate genetic parameters of first lactation 4,209 and 408 records of monthly test day milk yield and peak yield, respectively, of 408 Murrah buffaloes (sired by 62 bulls) calved in between 1993 and 2017 at ICAR-National Dairy Research Institute, Karnal.Result: Heritability of FL305DMY and peak yield was estimated as 0.35±0.17 and 0.33±0.16, respectively. Heritability estimates for mid-lactation monthly test day milk yields were found to be moderate. Genetic correlation of monthly test day milk yields with FL305DMY was positive and highly significant for TD-4 to TD-9 and TD-11. Peak yield showed high genetic and phenotypic association with FL305DMY. High genetic and phenotypic correlation among monthly test day milk yields, peak yield and FL305DMY suggested that TD-4 to TD-9 and TD-11 test day milk yields and peak yield could be used for the selection of elite animals.


2017 ◽  
Vol 52 (12) ◽  
pp. 1261-1267
Author(s):  
Andréa Carolina Santos de Souza ◽  
Marcos Paulo Gonçalves de Rezende ◽  
Paulo Luiz Souza Carneiro ◽  
Bárbara Machado Campos ◽  
Carlos Henrique Mendes Malhado

Abstract: The objective of this work was to assess the effect of editing and modeling of milk production data for genetic evaluation of Murrah buffaloes. Six strategies for evaluating milk production were analyzed: observed milk production (OMP); adjustment of milk production data to 305 (MP305) and 270 (MP270) days of lactation; removal of the 5 (MP5%) and 10% (MP10%) shortest lactation periods; and milk production along the lactation period as linear covariate (MPCO). Genetic parameters were estimated using the Bayesian inference, with heritability estimates of 0.19 to 0.23 and repeatability estimates of 0.35 to 0.36. Sires classified by OMP were high correlated to those classified by the other models, however, correlations to MP270, MP305 and MPCO decreased when considering only the best 20% sires. OMP showed greater differences in absolute mean deviations when compared with MPCO, MP270 and MP305. The strategies of analysis had similar heritabilities and stabilities. However, changes in the ranking of sires with better classifications, due to overestimation of genetic values, as occurred in the models MP305, MP270 and MPCO, may lead to a decrease in the genetic progress of the herd.


2012 ◽  
Vol 55 (5) ◽  
pp. 420-426
Author(s):  
N. G. Hossein-Zadeh

Abstract. Calving records from the Animal Breeding Centre of Iran collected from January 1995 to December 2007 and comprising 217973 calving events of Holsteins from 704 dairy herds were analysed using univariate and bivariate linear animal models to estimate heritabilities and genetic correlations for energy-corrected 305-d milk yield (ECM) in the first three lactations of Holstein cows. Genetic trends were obtained by regressing yearly mean estimates of breeding values on calving year. Average ECM increased from parity 1 through parity 3. Estimates of heritabilities were from 0.14 to 0.21 for ECM and decreased over the parities. The greatest genetic correlations were between ECM2 and ECM3 (0.96), and the greatest phenotypic correlations were between ECM1 and ECM2 (0.57) and ECM2 and ECM3 (0.57). The high and positive genetic correlations between ECM traits at different lactations are evidence for common genetic and physiological mechanism controlling these traits. There were positive and increasing phenotypic and genetic trends for ECM over the years (P<0.001). Higher heritability of the ECM in the first parity along with the high genetic correlations between first-lactation ECM with these traits in other lactations shows that higher potential exists for selecting animals for ECM based on their first parity records.


1996 ◽  
Vol 79 (10) ◽  
pp. 1895-1898 ◽  
Author(s):  
M. Analla ◽  
I. Jiménez-Gamero ◽  
A. Muñoz-Serrano ◽  
J.M. Serradilla ◽  
A. Falagán

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