scholarly journals Application of an Autoregressive Process to Estimate Genetic Parameters and Breeding Values for Daily Milk Yield in a Tropical Herd of Lucerna Cattle and in United States Holstein Herds

1998 ◽  
Vol 81 (10) ◽  
pp. 2738-2751 ◽  
Author(s):  
J.G.V. Carvalheira ◽  
R.W. Blake ◽  
E.J. Pollak ◽  
R.L. Quaas ◽  
C.V. Duran-Castro
Keyword(s):  
United States ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Autoregressive Process ◽  
Breeding Values ◽  
Daily Milk Yield ◽  
Daily Milk

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 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 Random Regression Model for Genetic Evaluation and Early Selection in the Iranian Holstein Population

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3492
Author(s):  
Yasamin Salimiyekta ◽  
Rasoul Vaez-Torshizi ◽  
Mokhtar Ali Abbasi ◽  
Nasser Emmamjome-Kashan ◽  
Mehdi Amin-Afshar ◽  
...  
Keyword(s):  
Milk Yield ◽  
Cross Validation ◽  
Early Selection ◽  
Random Regression ◽  
Likelihood Method ◽  
Early Lactation ◽  
Breeding Values ◽  
Daily Milk Yield ◽  
Holstein Population ◽  
Daily Milk

The objective of this study was to use a model to predict breeding values for sires and cows at an early stage of the first lactation of cows and progeny groups in the Iranian Holstein population to enable the early selection of sires. An additional objective was to estimate genetic and phenotypic parameters associated with this model. The accuracy of predicted breeding values was investigated using cross-validation based on sequential genetic evaluations emulating yearly evaluation runs. The data consisted of 2,166,925 test-day records from 456,712 cows calving between 1990 and 2015. (Co)-variance components and breeding values were estimated using a random regression test-day model and the average information (AI) restricted maximum likelihood method (REML). Legendre polynomial functions of order three were chosen to fit the additive genetic and permanent environmental effects, and a homogeneous residual variance was assumed throughout lactation. The lowest heritability of daily milk yield was estimated to be just under 0.14 in early lactation, and the highest heritability of daily milk yield was estimated to be 0.18 in mid-lactation. Cross-validation showed a highly positive correlation of predicted breeding values between consecutive yearly evaluations for both cows and sires. Correlation between predicted breeding values based only on records of early lactation (5–90 days) and records including late lactation (181–305 days) were 0.77–0.87 for cows and 0.81–0.94 for sires. These results show that we can select sires according to their daughters’ early lactation information before they finish the first lactation. This can be used to decrease generation interval and to increase genetic gain in the Iranian Holstein population.

Random regression animal models for genetic evaluation of test-day milk yield and milking duration in Saudi dairy goats

2018 ◽  
Author(s):  
A.A. Amin
Keyword(s):  
Milk Yield ◽  
Genetic Correlations ◽  
Random Regression ◽  
Dairy Goats ◽  
Data Set ◽  
Breeding Values ◽  
Sample Test ◽  
Early Production ◽  
Daily Milk Yield ◽  
Daily Milk

Random regression animal model was applied for analyzing the relationships between daily milk yield (MK) and milking duration (DR) in dairy goats comparing with reviewed estimates in dairy cows. The current analyzed data involved 17345 sample test-day records from multiparous Saudi dairy goats. A cubic random regression was applied for representing additive genetic variances in all studied traits across all different days in milk (12 groups). Based on multi-lactation random regression data-set analysis, the role of inheritance was greatest during the later stages of lactation. Heritability estimates of daily milk yield (h2MK) ranged from 0.15 to 0.54. While estimates of heritability for milking duration (h2DR) were very low during the first 60 days of lactation, being not more than 0.04. During the 2nd half of lactation the estimates of h2DR ranged from 0.35 to 0.39. Results of genetic variations for lactation records during early production life showed that highest milk harvest with intermediate milking rate could be achieved. Estimates of expected breeding values for milk yield and milking duration increased in different rates with progressing days in milk groups. These results indicated that individual selection results would be favorably achieved during the late part of lactation. Additive genetic correlations between measures of all traits at different lactation months continuously decreased as the interval between test days increased. Additive genetic correlations between milking duration and milk yield were positive and considerably high. Correlations between expected breeding values of both traits ranged from 0.41 to 0.83 (mean = 0.69) across different lactation months. More details on estimates of breeding values, estimates of permanent environmental and additive genetic correlations for all traits were tabulated.

scholarly journals HEAT STRESSED HOLSTEIN HEIFERS - THRESHOLD DETERMINATION IN CENTRAL CROATIA

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
V. Gantner ◽  
P. Mijić ◽  
K. Kuterovac ◽  
Z. Barać ◽  
K. Potočnik
Keyword(s):  
Milk Yield ◽  
Threshold Value ◽  
Least Square ◽  
Dairy Farmers ◽  
Daily Production ◽  
Breeding Values ◽  
Daily Milk Yield ◽  
Financial Losses ◽  
Daily Milk

In the light of increasingly rapid climate change worldwide, and with the purpose of reduction of financial losses of dairy farmers and enabling the sustainable farming, the necessity of implementation of breeding values for heat resistance in breeding strategies, have become more and more pronounced. Estimation of breeding values requires determination of THI threshold value. Therefore, the objective of this research was to determine the THI threshold value for Holstein heifers in environmental conditions in Central Croatia. With that purpose individual test-day records of Holstein heifers with records of ambient temperature and relative humidity in the barns collected in regular milk recording from January 2006 to December 2012 were analysed. The THI threshold values for daily milk yield were determined by least square analyses of variance for each given THI value (from 65 to 76) using the PROC MIXED (SAS). The THI ≥ 65 cause significant change in Holstein heifers’ daily production. Significant decrease of daily milk yield was observed at THI = 65 with estimated drop from 0.087 till 0.254 kg milk/day (THI from 65 – 76). The THI = 65, as the lowest value at which significant decrease in daily milk yield was determined was taken as the threshold value for Holstein heifers in Central Croatia.

Effect of Bypass Protein on Milk Production and Economic of Lactating Crossbred Cows

2020 ◽  
Vol 7 (01) ◽  
Author(s):  
RATNESH K CHOUDHARY ◽  
A Saran ROY ◽  
N K SINGH3 ◽  
SANJAY KUMAR ◽  
RAUSHAN K SINGH
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Crossbred Cows ◽  
Lactating Cows ◽  
Feed Cost ◽  
Total Diet ◽  
T1 And T2 ◽  
Daily Milk Yield ◽  
On Farm ◽  
Daily Milk

An On-Farm Trial was conducted on 24 lactating crossbred cows for assessment of feeding formaldehyde treated mustard cake (bypass protein) on milk production and economic analysis of lactating cow. Cows were divided into three groups having 8 cows each, treatments were farmers’ practice (FP); (Control): The lactating animals under this group were fedas per the feeding schedule of the farmers (5 kg. dry roughage as rice straw + 6 hrs grazing as local grass and 4 kg. commercial concentrates), T1: The lactating animals under this group were fed as per farmers practicewith 12% mustard cake of total diet was provided to the cow by replacing the same amount of commercial concentrates andT2: The lactating animals under this group were fed as per farmers practicewith 12% formaldehyde treated mustard cake of total diet was provided to the cow by replacing same amount of commercial concentrates. The average daily milk yield of lactating cows under FP, T1 and T2 was 8.58, 8.82 and 9.85 kg per cow, respectively. Differences between FP and T2 were significant. The daily increase in milk yield was 1.27 kg and 1.03 kg in cows fed T2diet over the cows fed FP and T1diet, respectively. The B: C ratios for FP, T1 and T2 groups were 2.6, 3.0 and 3.3, respectively. The feed cost reduced in T2 group by Rs. 8.64 and increased milk production by 1.27 kg in respect to FP group.

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