Factors affecting weight and age at first calving, first lactation milk yield in Gir cows

Author(s):  
Basdev Singh ◽  
Pushkraj Sawant ◽  
Dhruvaraj Sawant ◽  
Sachin Todkar ◽  
Richa Jain

The present study was undertaken on data of 113 Gir cows maintained at Kasturba Gram Dairy Farm, Indore, Madhya Pradesh, India over a period of 18 years from 1995 to 2012, based on age at first calving. The overall means for weight at first calving (WFC), age at first calving (AFC), and first lactation milk yield (FLMY) were 402.22± 1.28 kg, 1709.04± 51.92 days and 1664.95± 280.72 litres respectively. The heritability estimates for WFC, AFC and FLMY were 0.248± 0.234, 0.307± 0.206 and 0.112± 0.252 respectively. The genetic correlation between WFC and AFC was positive and significant, while it was negative in between WFC and FLMY. The genetic correlation between AFC and FLMY was low and negative. The phenotypic correlations between all traits were positive.

Author(s):  
Pushkraj Sawant ◽  
Basdev Singh ◽  
Dhruvaraj Sawant ◽  
Satya Prakash Yadav ◽  
Basant Kumar Bhinchhar

A total record of 113 Gir individuals spread over a period of 18 years from 1995 to 2012, were analyzed to estimate the effect of genetic and non genetic factors on first lactation period, first lactation milk yield and first dry period. The overall means for first lactation period (FLP), first lactation milk yield (FLMY) and first dry period (FDP), were 343.58± 10.37 days, 1664.95± 280.72 litres and 177.29± 10.59 days respectively. The heritability estimates for FLP, FLMY and FDP were 0.168± 0.238, 0.112± 0.252 and 0.419± 0.234 respectively. The genetic correlation between FLP and FLMY was positive and significant, while it was low and negative between FLP and FDP. The genetic correlation between FLMY and FDP was positive and highly significant. The phenotypic correlations between all traits were high and positive.


Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.


2020 ◽  
Vol 42 ◽  
pp. e50181
Author(s):  
Mahdi Elahi Torshizi ◽  
Homayoun Farhangfar

The objective of this study was to estimate lactation curve parameters with Dijkstra mechanistic model and to evaluate genetic and phenotypic relationships between the parameters and the average somatic cell count in primiparous cows. The finding indicated that heritability estimates for partial milk yield (PMY1, PMY2 and PMY3), total 305-day milk yield (TMY305), decay parameter (λ2), age at first calving (AFC) and peak yield (PY) were moderate while the heritability of persistency (PS%), average somatic cell score (AVGSCS), time to peak yield (TP), initial milk production (λ0), specific rate of cell proliferation at parturition (λ1), and specific rate of cell death (λ3) were quite low. Genetic correlations between both AFC and PS% traits with average somatic cell scores was negative (-0.047 and -0.060) but low positive genetic correlation were between partial milk yields (PMY1 and PMY3) while negative genetic correlation (-0.06) was obtained between TMY305 and AVGSCS. Differences between TMY305 of cows with less than 100000 cells mL-1 and cows with >1,500,000 cells mL-1 was approximately 708 Kg and is equivalent to 8% loss of milk yield/cow during lactation period and also loss of persistency (11.1 %( was shown for the extreme classes of SCC in this study.


1986 ◽  
Vol 66 (1) ◽  
pp. 53-65 ◽  
Author(s):  
T. R. BATRA ◽  
A. J. LEE ◽  
A. J. McALLISTER

The relationships between reproduction traits, body weight and milk yield were investigated using data from 1611 heifers and 733 cows from two lines of the National Cooperative Dairy Cattle Breeding Project. The data were analyzed separately for heifers and cows within lines using a mixed linear model containing fixed effects for station, year of birth, season of birth and random effect of sires. Heritability estimates and genetic correlations were estimated by a paternal half-sib analysis. Heritability estimates for heifer and cow reproduction traits ranged between 0 and 26% while those of body weights at calving and 112 d postpartum and milk yield ranged from 24 to 43%. Heifers with difficult calving had a higher incidence of retained placenta than those with normal calving. Phenotypic correlations between heifer reproduction traits and milk yield during first lactation were small. High milk production in cows was associated with longer calving interval. Phenotypic correlations between heifer's and cow's reproduction traits were small. Difficult calving in heifers impairs reproductive performance after calving resulting in greater number of days from calving to first and last breeding and leading to a longer calving interval. Key words: Reproduction traits, heifers, cows, milk yield, dairy cattle


2016 ◽  
Vol 84 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Maria Selvaggi ◽  
Angela Gabriella D'Alessandro ◽  
Cataldo Dario

The aims of the study described in the Research Communication were to determine the level of influence of some environmental factors on milk yield and quality traits, including lactose, and lactation length in ewes belonging to three different Italian breeds and to estimate the heritability for the same traits. A total of 2138 lactation records obtained from 535 ewes belonging to three different Italian breeds (Comisana, Leccese, and Sarda) were used. Breed significantly affected all of the considered traits. Moreover, year of lambing affected milk yield and lactation length without influence on milk quality traits. Parity affected significantly only the milk yield, whereas type of birth showed its effect on milk yield, fat, protein, and lactose yield. On the whole, the presently reported heritability estimates are within the range of those already obtained in other dairy breeds by other authors, with values for lactation length being very low in all the investigated populations. Considering the heritability estimates for lactose content and yield, to the best of our knowledge, there is a lack of information on these parameters in ovine species and this is the first report on heritability of lactose content and yield in dairy sheep breeds. Our results suggest that genetic variability for milk traits other than lactation length is adequate for selection indicating a good response to selection in these breeds.


10.5219/1336 ◽  
2020 ◽  
Vol 14 ◽  
pp. 744-749
Author(s):  
Vladimí­r Tančin ◽  
Šimon Mikláš ◽  
Maroš Čobirka ◽  
Michal Uhrinčať ◽  
Lucia Mačuhová

Under the practical conditions, it is important to evaluate the factors affecting milk performance. Data from test day yield and milk components should be useful for such evaluation. The aim of the experiment was to study the effect of season, udder health (by somatic cell counts SCC), parity, stage of lactation on milk production, milk components, and SCC under the practical conditions. Also, the frequency of incidence of high SCC during the season was observed. The experiment was realized on one dairy farm in dairy practice. The experiment lasted from December 2015 to October 2017. We examined 481 Holstein dairy cows (6910 milk samples). Milk samples were collected once per month – performed by recording test day. Only cows with 9 – 11 test days were evaluated. The effect of season, parity, stage of lactation, and SCC influenced most of the studied traits. The milk yield was highest at 2nd lactation. In the following lactations, the milk yields were decreasing. The SCC significantly increased with advanced parity. The elevated SCC was found in the beginning and in the final part of lactation. SCC as a factor significantly reduced milk yield, lactose content but increased fat and protein content. In conclusion, under practical conditions, the management should use the data from test days and analyze them for a better understanding of the performance efficiency at the farm level and for implementing more sophisticated decision making in farming.


2017 ◽  
Vol 15 (2) ◽  
pp. e0402 ◽  
Author(s):  
Hugo H. Montaldo ◽  
Alejandra Pelcastre-Cruz ◽  
Héctor Castillo-Juárez ◽  
Felipe J. Ruiz-López ◽  
Filippo Miglior

The objective of this study was to evaluate genotype × environment  interaction (G×E) between Canada, the United States and Mexico for fertility and milk yield traits using genetic correlations between countries estimated from genetic evaluations of sires. Genetic correlation between Mexican and Canadian Holsteins for age at first calving was ≤ 0.48 and lower than the simulated value obtained accounting for data structure and selection effects. For calving interval, genetic correlation between Mexico and Canada ranged from 0.48 to 0.69. Genetic correlation between calving interval in Mexico (multiplied by -1) and daughter pregnancy rate in the United States ranged from 0.64 to 0.73, and was lower than simulated and actual Canada-United States values. Genetic correlations between Mexico and Canada and the United States for milk yield traits were ≥ 0.83, similar to simulated genetic correlations, but lower than Canada-United States values (≥ 0.93). Heritability estimates for age at first calving, calving interval, milk yield, fat yield, protein yield, fat content, and protein content for the Mexican Holstein population were 0.06, 0.03, 0.18, 0.20, 0.19, 0.46, and 0.49, respectively. G×E interaction effects between Canada and Mexico for age at first calving were high, whereas G×E interaction effects between Canada and Mexico for calving interval and between daughter pregnancy rate in the United States and calving interval in Mexico were moderate. G×E interaction effects for milk yield traits between Canada or the United States with Mexico in registered Holsteins were low.


Author(s):  
Kiros Abebe ◽  
Tilaye Demissie

Background: Productive and reproductive performances are the most important parameters in the Ehiopian dairy sector. The objective of the current study was to assess milk yield, reproductive performances of crossbred dairy cattle and occurrence of reproductive health problems and veterinary services provider/s. Methods: A cross-sectional study using semi-structured questionnaire was used to collect information from 160 randomly selected dairy farm owners found in urban and peri-urban areas of Assela, Bishoftu, Holetta and Sululta of the central highlands of Ethiopia. Result: The higher average daily milk yields were 11.7 and 11.2 litres in urban and peri-urban Bishoftu. The average age at first service of crossbred dairy heifers was 18.8 months in urban and 19.1 months in peri-urban Bishoftu, respectively. The average age at first calving of crossbred dairy heifers was 27.8 months in urban Bishoftu and 28.1 months in peri-urban Bishoftu areas. The longest average age at first service (29.3 months) and age at first calving (38.3 months) were in peri-urban Assela. The number of services per conception was 1.4 in urban Assela and 1.3 in peri-urban Assela and these were shorter than the 1.65 from urban Bishoftu and the 1.85 of peri-urban Bishoftu areas. The average 168.0 days calving to conception interval from peri-urban Assela was the longest calving to conception interval in this study. The average calving intervals 14.9 and 13.9 months of peri-urban Assela and Sululta were relatively longer than the respective urban areas.


2016 ◽  
Vol 50 (3) ◽  
Author(s):  
Basdev Singh ◽  
Pushkraj Sawant ◽  
Dhruvaraj Sawant ◽  
Gautam Dutt ◽  
Sachin Todkar

The present study was undertaken on data of 150 Frieswal cows (a new strain of Sahiwal x Holstein Friesian) maintained at Military Dairy Farm, Agra, over a period of 15 years from 1996-2010, based on age at first calving. The overall means for age at first calving (AFC), weight at first calving (WFC), first lactation milk yield (FLMY), first lactation period (FLP), first dry period (FDP) and first calving interval (FCI) were 928.07±0.08 days, 369.87±0.92 kg, 4054.35±22.14 litres, 301.84±0.26 days, 99.40±0.15 days and 401.33±0.33 days respectively. The period of calving has significant influence on AFC and WFC, whereas non-significant influence on FLMY, FLP and FDP. The season showed significant influence on all the traits under study except FLMY. Both period and season has highly significant influence on FCI.


2018 ◽  
Vol 58 (9) ◽  
pp. 1575 ◽  
Author(s):  
Hinayah Rojas de Oliveira ◽  
Henrique Torres Ventura ◽  
Edson Vinícius Costa ◽  
Mariana Alencar Pereira ◽  
Renata Veroneze ◽  
...  

Meta-analysis based on a random-effects model is used to summarise and overcome the variability between divergent parameter estimates. We proposed a meta-analysis of published heritability and genetic-correlation estimates for reproduction, growth and carcass traits in purebred Nellore cattle. In total, 197 heritability and 107 genetic-correlation estimates from 62 scientific publications were used here. Most of traits (gestation length; weights at birth, 120, 210, 365 and 550 days of age; mature weight and all carcass traits) presented direct heritability estimates ranging from 0.20 to 0.40. Age at first calving presented the lowest value among direct heritabilities (0.1498); whereas the higher values (>0.40) were found for scrotal circumference at different ages and for weight at 450 days of age. Low maternal heritability estimates (ranging from 0.06 to 0.11) were observed for all growth traits. With the exception of correlation estimates involving the age at first calving, all other correlations were positive. High correlations (>0.85) were found mainly for the same trait at different ages. The results reported here will give support to genetic evaluations when reliable estimates for different traits in purebred Nellore cattle are not available.


Sign in / Sign up

Export Citation Format

Share Document