Estimation of genetic parameters for daily milk yield of primiparous Ayrshire cows by random regression test-day models

2000 ◽  
Vol 66 (3) ◽  
pp. 251-261 ◽  
Author(s):  
Anne Kettunen ◽  
Esa A. Mäntysaari ◽  
Jukka Pösö
Keyword(s):  
Milk Yield ◽  
Genetic Parameters ◽  
Random Regression ◽  
Regression Test ◽  
Daily Milk Yield ◽  
Estimation Of Genetic Parameters ◽  
Daily Milk

scholarly journals Genetic parameters for milk yield in imported Jersey and Jersey-Friesian cows using daily milk records in Sri Lanka

2020 ◽  
Vol 33 (11) ◽  
pp. 1741-1754
Author(s):  
Amali Malshani Samaraweera ◽  
Vinzent Boerner ◽  
Hewa Waduge Cyril ◽  
Julius van der Werf ◽  
Susanne Hermesch
Keyword(s):  
Sri Lanka ◽  
Animal Models ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Random Regression ◽  
Breeding Values ◽  
Daily Milk Yield ◽  
Jersey Cows ◽  
Daily Milk ◽  
Friesian Cows

Objective: This study was conducted to estimate genetic parameters for milk yield traits using daily milk yield records from parlour data generated in an intensively managed commercial dairy farm with Jersey and Jersey-Friesian cows in Sri Lanka.Methods: Genetic parameters were estimated for first and second lactation predicted and realized 305-day milk yield using univariate animal models. Genetic parameters were also estimated for total milk yield for each 30-day intervals of the first lactation using univariate animal models and for daily milk yield using random regression models fitting second-order Legendre polynomials and assuming heterogeneous residual variances. Breeding values for predicted 305-day milk yield were estimated using an animal model.Results: For the first lactation, the heritability of predicted 305-day milk yield in Jersey cows (0.08±0.03) was higher than that of Jersey-Friesian cows (0.02±0.01). The second lactation heritability estimates were similar to that of first lactation. The repeatability of the daily milk records was 0.28±0.01 and the heritability ranged from 0.002±0.05 to 0.19±0.02 depending on day of milk. Pearson product-moment correlations between the bull estimated breeding values (EBVs) in Australia and bull EBVs in Sri Lanka for 305-day milk yield were 0.39 in Jersey cows and –0.35 in Jersey-Friesian cows.Conclusion: The heritabilities estimated for milk yield in Jersey and Jersey-Friesian cows in Sri Lanka were low, and were associated with low additive genetic variances for the traits. Sire differences in Australia were not expressed in the tropical low-country of Sri Lanka. Therefore, genetic progress achieved by importing genetic material from Australia can be expected to be slow. This emphasizes the need for a within-country evaluation of bulls to produce locally adapted dairy cows.

Phenotypic and genetic parameters for milk yield in traditional Nublang cattle (Bos indicus) of Bhutan

2015 ◽  
Vol 57 ◽  
pp. 25-30
Author(s):  
Jigme Dorji ◽  
Dhendup ◽  
Iona M. MacLeod
Keyword(s):  
Milk Yield ◽  
Genetic Improvement ◽  
Genetic Parameters ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Sustainable Utilization ◽  
Dual Purpose ◽  
Lactation Length ◽  
Daily Milk Yield ◽  
Daily Milk

SummaryThe Nublang is a unique dual-purpose breed ofBos indicuscattle found in Bhutan. They have been crossed with Mithun (Bos frontalis) andBos taurusbreeds in an effort to improve milk production leading to a decline in the population of purebred Nublang. An alternative to crossbreeding would be the genetic improvement of milk yield within purebred Nublang, thus allowing conservation and sustainable utilization of the pure breed. It is important to measure the genetic variability (heritability) of milk yield to assess the potential for genetic improvement within Nublang. Therefore this study estimated phenotypic and genetic parameters of milk yield using 2 052 test day milk yields from 66 cows recorded from 1997 to 2013 in the National Nublang Farm, Tashiyangphu. The average daily milk yield (DMY) was 2.12 ± 0.7 litres (N 2 052, range: 0.3–5.0 L, CV: 34 percent). Parity, month in milk and year all had a significant effect on DMY (P< 0.05). The average lactation milk yield (LMY) was 519.2 ± 151 L (N: 261, range: 115–881.7, CV: 29.1 percent) and average lactation length was 239 days. LMY was significantly influenced by parity (P< 0.05) and season of calving. The heritability of DMY and LMY was 0.22 ± 0.16 and 0.13 ± 0.20, respectively. The repeatability estimates were 0.45 ± 0.05 and 0.49 ± 0.08 for DMY and LMY, respectively. Overall the heritability and repeatability estimates of milk yields indicate potential for genetic improvement of milk yield in Nublang cattle through selection. However, it is recommended that a larger dataset is generated to enable more precise estimates of genetic parameters.

scholarly journals Estimation of genetic parameters and prediction of breeding values for some economic traits of Black Bengal Goat under farming condition

2020 ◽  
Vol 20 (1-2) ◽  
pp. 8-17
Author(s):  
MA Jalil ◽  
S Akther ◽  
MP Choudhury ◽  
MA Habib
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Breeding Values ◽  
Lactation Length ◽  
Total Milk ◽  
Daily Milk Yield ◽  
Black Bengal Goat ◽  
Daily Milk

The study was undertaken to evaluate the genetic progress of Black Bengal Goat (BBG) by estimating genetic parameters viz. heritability and breeding values for economically important productive and reproductive traits (birth weight, weight at 3, 6, 9 & 12 months, daily milk yield, lactation length, total milk yield and litter size of BBG goat population). Variance and co-variance components were analyzed applying Residual Maximum Likelihood (REML) approach by VCE 4.2.5 computer package. The heritability (h2) of birth weight was estimated as 0.2, which was low. The heritability estimates for 3-month weight (0.40), 6-month weight (0.50), 9-month weight (0.37) and 12-month weight (0.36) were found medium. Estimated h2 of daily milk yield, total milk yield and lactation length in this study were from 0.55 to 0.82.  h2 of litter size was 0.09. The maximum estimated breeding value (EBV) was found for 6 month body weight (12.94 kg), however, for daily milk yield, the value was 1.513 kg. The results found in this study revealed that genetic improvement of BBG for most of the traits is possible by selection and breeding. Bangladesh J. of Livestock Res. 20(1-2): 8-17, Jan-Dec 2013

scholarly journals Estimation the Genetic Parameters for Milk Yield in Romanian Spotted, Simmental Type Cattle Breed

2021 ◽  
Vol 24 (2) ◽  
pp. 105-121
Author(s):  
Rodica Stefania Pelmuș ◽  
Mircea Cătălin Rotar ◽  
Cristina Lazăr ◽  
Răzvan Alexandru Uță
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Cattle Breed ◽  
Random Regression ◽  
Breeding Value ◽  
Regression Test ◽  
Fat Yield ◽  
Heritability Estimates

Abstract The aim of this study was to estimate the genetic parameters for test-day traits milk yield and the breeding value in Romanian Spotted, Simmental type cattle. Random regression test-day animal model was used to estimate the genetic parameters. The number of records were 2062 test-day from 302 cows. The data were obtained from Romanian Breeding Association Romanian Spotted, Simmental type. The heritability estimates values for milk yield ranged between 0.377 and 0.417. The heritability for fat test-day yield in our study was low the values ranged between 0.117 and 0.236 and for protein test-day yield was medium, the values ranged between 0.308 and 0.372. The breeding value for the best ten cows for milk yield ranged from 1946.57 to 3250.38 kg, for fat yield were between 64.92 and 98.86 kg and for protein ranged from 67.26 to 102.21 kg. The correlations between test-day milk yields ranging from 0.28 to 1. Genetic correlations between test day fat and protein yields were high.

Sign in / Sign up

Export Citation Format

Share Document