Sahiwal cattle in Pakistan: genetic and environmental causes of variation in body weight and reproduction and their relationship to milk production

1999 ◽  
Vol 68 (1) ◽  
pp. 97-108 ◽  
Author(s):  
U. N. Khan ◽  
A. Dahlin ◽  
A. H. Zafar ◽  
M. Saleem ◽  
M. A. Chaudhry ◽  
...  

AbstractThe influence of genetic and environmental factors on body weight and reproduction and their relationship to milk production traits, were studied in data of about 4700 Sahiwal cows from Pakistan. (Co)variance components were estimated using restricted maximum likelihood (REML) procedure based on the expectation maximization algorithm applying an animal model. Mean weights of females were: at birth, 21·6 kg; at 1 year, 130 kg; and at 2 years, 222 kg. Records of age at calving, cow weight post partum and calving interval were studied in the first three parities, with parities considered as different traits. For primiparous cows the average values of these traits were: 44·1 months, 319 kg and 465 days, respectively. Mean stillbirth rate was 5·3%. Heritabilities ranged for body weight traits from 0·08 to 0·21, for age at calving from 0·10 to 0·13 and for calving interval from 0·03 to 0·07. Genetic correlations of age at first calving with calving interval and 305-day milk yield were low. The genetic correlation between 305-day milk yield and calving interval was positive (unfavourable) in first parity (0·68) but negative in the third (-0·47). Cows with a high genetic value for 305-day milk yield were heavier at first calving than were low-yielding cows (rg 0·57). The genetic change in reproductive traits over the period studied was close to zero, whereas a marked deterioration was found in phenotypic performance. It is concluded that improved feeding and management, along with some selection against poor reproduction in cows, are important for improvement of reproductive performance.

1978 ◽  
Vol 91 (1) ◽  
pp. 181-183
Author(s):  
S. S. Bhalaru ◽  
J. S. Dhillon

SummaryThe least-squares means for first lactation milk yield, yield per 100 kg of body weight at first calving, yield per day of first lactation length, yield per day of first calving interval and yield per day of age at second calving were 1692 ± 28·2, 339·8 ± 7·30, 5·51 ± 0·97, 3·37 ± 0·81 and 1·07 ± 0·03 kg and the heritabilities of those traits were 0·192 ± 0·086, 0·078 ± 0·078, 0·287 ± 0·096, 0·192 ± 0·086 and 0·305 ± 0·097 respectively. The genetic correlations of first lactation milk yield with various measures of efficiency of milk production (except with yield per 100 kg of body weight) were positive and high (> 0·80). These results indicate that milk yield per day of age at second calving may be used for the selection of buffaloes.


2005 ◽  
Vol 48 (3) ◽  
pp. 233-246 ◽  
Author(s):  
S. König ◽  
N. Chongkasikit ◽  
H.-J. Langholz

Abstract. Milk production in Thailand has been growing into an important agricultural sector, but it still faces numerous difficulties in environmental constraints. The main intention of this study was to identify significant environmental effects on production and fertility traits to give advices for farm management. Additionally, adjusting records for environmental impact is essential to define appropriate models for estimation of variance components and improving selection procedures. The data consists of production and reproduction records and body measurements from 2764 Holstein upgrade cows in 252 farms. With a body weight of 415 kg and a production level of 3668 kg milk Thai Holsteins only reach approximately 60 % of performances of Holsteins in temperate zones. Percentages of Holstein genes of cows and quality of roughage sources showed a certain effect on calving interval and services per conception but not on milk performances. Despite seasonal effects were not very pronounced on milk yield, there was a strong interaction between years and calving seasons. Estimates of variance components applying REML and animal models were in the range as expected, i.e. heritabilities for production traits between 0.34 and 0.37, for fertility lower than 0.03 and for body weight 0.46. Genetic correlations between fertility and production traits were near zero. Economic weights for milk yield and calving interval were derived as first derivation of profit functions and used for selection index calculations. Suc


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


1998 ◽  
Vol 66 (2) ◽  
pp. 307-318 ◽  
Author(s):  
A. Dahlin ◽  
U. N. Khan ◽  
A. H. Zafar ◽  
M. Saleem ◽  
M. A. Chaudhry ◽  
...  

AbstractData from about 4000 Sahiwal cows from eight large herds in Pakistan were used to study the influence of genetic and environmental factors on some milk production traits. First-lactation mean values were 1363 kg, 1395 kg and 252 days for milk yield up to 305 days after calving, total lactation yield and lactation length, respectively. Second and third lactation yields were proportionately 0·12 and 0·18 higher, respectively, at 305 days. The effect of herd-year at calving was by far the most important source of variation for all traits. Heritabilities estimated in uni- and trivariate analyses, using restricted maximum likelihood (REML) with an expectation maximization algorithm for an animal model, ranged from 0·14 to 0·17 for first-lactation traits. The estimates were generally lower for second lactation and higher for third lactation traits. Genetic correlation between lactations for the same trait were close to unity, whilst the phenotypic were considerably lower. Repeatabilities for milk yield traits were 0·42 and for lactation length 0·31. Genetic and phenotypic correlations between first-lactation 305-day milk yield and lactation length were 0·83 and 0·71, respectively. Genetic trends for all traits were close to zero but a substantial deterioration in performance, caused by negative environmental factors, was observed. Although the heritabilities were low, the prospects for genetic improvement are good, as indicated by a rather large additive genetic variation. A multivariate animal model, including the first three lactations of 305-day milk yield, was recommended for the most accurate prediction of breeding values for milk production.


Author(s):  
P. Panduranga Reddy ◽  
Siddalingswamy Hiremath ◽  
Krovvidi Sudhakar ◽  
Muralidhar Metta ◽  
R. Vinoo ◽  
...  

Background: The knowledge and estimation of genetic and non-genetic factors on the production and reproduction traits of Ongole cattle are important to enable the breeders to design efficient conservation strategies and adopt better selection methods, management practices and culling operations. Methods: Data available on 220 Ongole cows mated to 22 sires- at the Livestock Research Station, Mahanadi, Kurnool (District), Andhra Pradesh over a period of eight years was used for the present analysis. Result: Results in the present study revealed that performance of animals was improved in lactation milk yield (LMY, 1063.33±31.13), 305 lactation milk yield (LMY, 1019.83±29.22), lactation length (LL, 266.26±5.6), less calving interval (CI, 497.95±8.58), service period (SP, 188.19±5.17) and dry period (DP, 214.79±19.6) compared to earlier reports. Parity and period have shown significant effect on all production traits and calving interval. Effect of season was non-significant on all productive and reproductive traits. Most of the heritability estimates for milk production traits were medium in range but low for reproductive traits. The correlations between productive traits and calving interval were negative.


2020 ◽  
Vol 87 (3) ◽  
pp. 330-333
Author(s):  
Subrata Koloi ◽  
Ajoy Mandal

AbstractThe study reported in this Research Communication was conducted to estimate genetic parameters for different lactation persistency indices and their association with reproductive traits in Jersey crossbred cattle. Data on lactation traits (part lactation yields and 305-days milk yield) comprising all lactations as well as reproductive traits viz. calving interval, conception rate and gestation length of 378 Jersey crossbred cattle, maintained at National Dairy Research Institute, Kalyani, West Bengal, India, were collected over a period of 35 years (1982–2016). Five lactation persistency indices of animals (P21, P31, P32, P4 and P5) were calculated using ratio method. A total of six different animal models, ignoring or including maternal genetic or permanent environmental effects, were fitted for all persistency traits. The best model was chosen after testing the improvement of the log-likelihood values. The estimates of direct heritability were low in magnitude and ranged from 0.02 to 0.14 for the studied traits under the best fitted animal model. The permanent maternal environmental (c2) effects of different lactation persistency indices accounted for 2–9% of the total phenotypic variance in this study. Estimated genetic correlations of lactation persistency indices with all studied reproductive traits were low to moderate and negative (−0.11 to −0.68), except for calving interval. Phenotypic correlations of lactation persistency measures with studied reproductive traits were low (0.01 to 0.15). The low heritability estimates of all the persistency indices indicate some limited scope of genetic improvement of lactation persistency of animals through selection under the prevailing management conditions.


2013 ◽  
Vol 58 (No. 12) ◽  
pp. 554-565 ◽  
Author(s):  
L. Zavadilová ◽  
V. Zink

The objectives of this study were to estimate heritabilities of and genetic correlations among longevity, milk production, and female fertility traits of Holstein cows. Fertility traits were days open, interval from parturition to first service, and days between the first and last insemination in the first and second lactation, respectively. Production traits were first lactation milk, fat, and protein yield. Functional longevity was defined as the number of days between the first calving and culling, i.e. the length of the productive life. The linear animal model included fixed effects of month-year of first calving, regression on age at first calving, regression on milk yield (only for longevity), and random effects of herd-year, animal, and residual. Heritability estimates for fertility traits ranged from 0.02 ± 0.009 to 0.06 ± 0.004. Heritability of longevity was 0.09. Heritability estimates for production traits ranged from 0.29 ± 0.009 (fat and protein yield) to 0.34 ± 0.009 (milk yield). Genetic correlations of longevity with fertility were moderate and favourable, ranging from –0.37 ± 0.068 to –0.44 ± 0.055, except the days between the first and last insemination in the second lactation. Genetic correlations of fertility with production traits were moderate to high and unfavourable, ranging from 0.48 ± 0.042 to 0.65 ± 0.034. Substantial herd-year correlations were found between fertility traits. Residual correlations were small except for those between production traits (> 0.85) and between days open and days between the first and last insemination (0.87). Month-year of first calving effects for longevity declined between 1994 and 2002, while those for production traits and for fertility increased slightly or remained stable during this period. Between 1991 and 2003, genetic trend for longevity declined and increased for production. Estimated genetic changes for fertility were unfavourable.


1982 ◽  
Vol 98 (2) ◽  
pp. 461-465
Author(s):  
V. K. Taneja ◽  
S. B. Basu ◽  
D. S. Bhatnagar

SUMMARYThe genetic parameters of lifetime production traits and their relationship with milk yield in first, second and third lactations were estimated from information on 753 Tharparkar cows. The heritability estimates for milk yield in first, second and third lactations were 0·22 ± 0·10, 0·33 ± 0·14 and 0·49 ± 0·17 and for number of lactations completed, lifetime milk production, number of days in milk and herd life 0·58 ± 0·23, 0·51 ± 0·22, 0·54 ± 0·22 and 0·34 ± 0·20 respectively. The genetic and phenotypic correlations among the four lifetime production traits were in the range of 0·83–1·0 and 0·84–0·85 respectively. The phenotypic correlations of milk yield in first, second and third lactations with lifetime production traits were significant and ranged between 0·15 and 0·56. The corresponding genetic correlations ranged between 0·26 and 0·83. For the first three lactations, the genetic correlations of lifetime traits with the third lactation were high and that between lifetime milk yield and yield in third lactation the highest (0·83 ± 0·17). The direct and correlated responses from single trait selection were also estimated.


2017 ◽  
Vol 84 (4) ◽  
pp. 430-433 ◽  
Author(s):  
Jun Li ◽  
Aixin Liang ◽  
Zipeng Li ◽  
Chao Du ◽  
Guohua Hua ◽  
...  

This Research Communication describes the association between genetic variation within the prolactin (PRL) gene and the milk production traits of Italian Mediterranean river buffalo (Bufala mediterranea Italiana). High resolution melting (HRM) techniques were developed for genotyping 465 buffaloes. The association of genetic polymorphism with milk production traits was performed and subsequently the effects of parity and calving season were evaluated. Single nucleotide polymorphisms (SNPs) were identified at exons 2 and 5 and at introns 1 and 2. All the SNPs were in Hardy–Weinberg equilibrium, and statistical analysis showed that the polymorphism of intron1 was significantly (P < 0·05) associated with milk yield, milk protein content and peak milk yield. The average contribution of the intron1 genotype (r2intron1) to total phenotypic variance in milk production traits was 0·09, and the TT genotype showed lower values than CC and CT genotypes. A nonsynonymous SNP was identified in exon 2, which resulted in an amino acid change from arginine to cysteine. Moreover, the polymorphism of exon 2 was associated significantly with milk fat content (P < 0·05), and the buffaloes with TT genotype showed higher total fat content than the buffaloes with CT genotype. These findings provide evidence that polymorphisms of the buffalo PRL gene are associated with milk production traits and PRL can be used as a candidate gene for marker-assisted selection in Italian Mediterranean river buffalo breeding.


Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1809-1816 ◽  
Author(s):  
Jianbo Yao ◽  
Samuel E Aggrey ◽  
David Zadworny ◽  
J Flan Hayes ◽  
Urs Kühnlein

Sequence variations in the bovine growth hormone (GH) gene were investigated by single strand conformation polymorphism (SSCP) analysis of seven amplified fragments covering almost the entire gene (2.7 kb). SSCPs were detected in four of these fragments and a total of six polymorphisms were found in a sample of 128 Holstein bulls. Two polymorphisms, a T→C transition in the third intron (designated GH4.1) and an A→C transversion in the fifth exon (designated GH6.2), were shown to be associated with milk production traits. GH4.1c/GH4.1c bulls had higher milk yield than GH4.1c/GH4.1t (P ≤ 0.005) and GH4.1t/GH4.1t (P ≤ 0.0022) bulls. GH4.1c/GH4.1c bulls had higher kg fat (P ≤ 0.0076) and protein (P ≤ 0.0018) than GH4.1c/GH4.1t bulls. Similar effects on milk production traits with the GH6.2 polymorphism were observed with the GH6.2a allele being the favorable allele. The average effects of the gene substitution for GH4.1 and GH6.2 are similar, with ±300 kg for milk yield, ±8 kg for fat content and ±7 kg for protein content per lactation. The positive association of GH4.1c and GH6.2a with milk production traits may be useful for improving milk performance in dairy cattle.


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