• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1189-1192
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• 2000

The experiment was conducted on 69 cows to identify the quantitative variations of some economic traits of five genetic groups as $Local{\times}Friesian $ $F_1$, $Local{\times}Sahiwal$ $F_1$, Local (indigenous zebu type), $Local{\times}Sindhi $ $F_1$, and $Local{\times}Hariana$ $F_1$. The traits studied were age at weaning, age at first heat, age at first conception, services per conception, daily milk yield, lactation length, lactation yield and post partum heat period. The records on milking and reproduction performances of cows and heifers were obtained from farm register and by interviewing the farmers. It was observed that the lowest age at weaning, age at first heat and age at first conception were $5.37{\pm}0.24$, $27.17{\pm}1.72$ and $27.83{\pm}1.82$ months respectively in $Local{\times}Hariana$ $F_1$. Services per conception were lowest in $Local{\times}Sahiwal$ $F_1$ $(1.08{\pm}0.18)$ although not significantly (p>0.05) affected by farms, genetic groups and $farm{\times}genetic$ groups interaction. Average daily milk yield was highest in $Local{\times}Friesian$ $F_1$ $(5.81 {\pm}0.40 kg)$. Lactation length and lactation yield were highest in $Local{\times}Sahiwal$ $F_1$ ($299.38{\times}9.74$ days and $1863.00{\pm}141.00kg $ respectively). Average post partum heat period was lowest in $Local{\times}Sindhi$ $F_1$ ($3.19{\pm}0.38$ months). Least squares ANOVA showed that farm had significant (p<0.001) effect on age at weaning, age at first heat, age at first conception and post partum heat period. There was insignificant (p>0.05) effect of farm on services per conception, daily milk yield, lactation length and lactation yield, whereas genetic groups had a significant effect for all the traits under review except services per conception. $Farm{\times}genetic$ groups interaction was insignificant for all of the traits under consideration except age at weaning.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.923-930
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• 2009

This study was conducted to compare three models: two random regression models with and without considering heterogeneity in the residual variances and a lactation model (LM) for evaluating the genetic ability of Holstein cows in Korea. Two datasets were prepared for this study. To apply the test-day random regression model, 94,390 test-day records were prepared from 15,263 cows. The second data set consisted of 14,704 lactation records covering milk production over 305 days. Raw milk yield and composition data were collected from 1998 to 2002 by the National Agricultural Cooperative Federation' dairy cattle improvement center by way of its milk testing program, which is nationally based. The pedigree information for this analysis was collected by the Korean Animal Improvement Association. The random regression models (RRMs) are single-trait animal models that consider each lactation record as an independent trait. Estimates of covariance were assumed to be different ones. In order to consider heterogeneity of residual variance in the analysis, test-days were classified into 29 classes. By considering heterogeneity of residual variance, variation for lactation performance in the early lactation classes was higher than during the middle classes and variance was lower in the late lactation classes than in the other two classes. This may be due to feeding management system and physiological properties of Holstein cows in Korea. Over classes e6 to e26 (covering 61 to 270 DIM), there was little change in residual variance, suggesting that a model with homogeneity of variance be used restricting the data to these days only. Estimates of heritability for milk yield ranged from 0.154 to 0.455, for which the estimates were variable depending on different lactation periods. Most of the heritabilities for milk yield using the RRM were higher than in the lactation model, and the estimate of genetic variance of milk yield was lower in the late lactation period than in the early or middle periods.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.1-6
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• 2010

The objectives of this study were to i) investigate genetic performance for linear type traits of individual Holstein dairy cows, especially focusing on comparative traits, and to estimate genetic variances for these traits using actual data, and ii) compare genetic performance and improvement of progeny by birth country of the cows. Linear type traits defined with five comparative traits on this study were general stature composite (GSC), dairy capacity composite (DCC), body size composite (BSC), foot and leg composite (FLC), and udder composite (UDC). These traits were scored from 1 to 6 with 1 = poor, 2 = fair, 3 = good, 4 = good plus, 5 = very good and 6 = excellent. Final scores (FS) were also included in this study. Data used was collected from the years 2000 to 2004 by the Korea Animal Improvement Association (KAIA). Only data of more than five tested cows by herd appraisal date and by sires having more than ten daughters were included to increase the reliability of the data analyses. A total of 30,204 records of the selected traits, which was collected from 26,701 individuals having pedigree information were used. Herd appraisal date, year of age, lactation stage (grouped by month), and time lagged for milking (in hours) were assumed as fixed effects on the model. Animal additive genetic effects considering pedigree relationship and residual errors were assumed with random effects. Year of age at appraisal date was classified from one to nine years of age, assigning the value of nine years of age for animals that were greater than or equal to nine years of age. From our results, the estimate for heritability was 0.463, 0.346, 0.473, 0.290, and 0.430 on GSC, DCC, BSC, FLC and UDC, respectively. The estimate for FS heritability was 0.539. The greatest breeding values for GSC were estimated for Canada, with the breeding values for American lines increasing for 10 years starting in 1989 but tending to decrease after that until 2004. For DCC, the breeding values for American and Canadian lines showed similar patterns until 1999, after which the breeding values for the American lines declined sharply. For BSC, data from Korea, Canada and the USA followed similar trends overall except when the breeding values of the American lines decreased starting in 1999. Overall, the methods used to evaluate genetic performance in this study were acceptable and allowed for the discovery of differences by country of genetic origin, likely due in part to the American use of selection indexes based primarily on milk yield traits until methods for evaluating other traits began to emerge.

• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.15-20
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• 2006

The data used in the study were taken from the national dairy genetic evaluation of bulls from 1986 up to 2001. It was conducted to compare the phenotypic performance and genetic merits in terms of production traits, linear traits and selection indexes of four types of dairy semen (TypeⅠ:semen from Korean proven bull, Type Ⅱ:semen from proven bull imported by National Agricultural Cooperative Federation(NACF), Type Ⅲ:semen imported from USA, Type Ⅳ:semen imported from Canada) used in Korea. The result of national dairy genetic evaluation was used to compare genetic merits. Type Ⅲ was superior in the phenotypic performance of milk yield, milk fat and milk protein and was significantly different from Type Ⅰ. Types of semen were not significantly different in fat when semen from bull born after 1991 were compared. Likewise, types of semen were not significantly different in the genetic merit for milk yield, milk fat, milk protein and milk protein %. Moreso, for profit index (MFP) and Korean type production index (KTPI) it was not statistically different. However type Ⅰ was superior in milk fat % and was significantly different from other types. Type Ⅳ was superior in Final Score of conformation test (FS) and Udder Composite Index (UDC) and significantly different from Type Ⅰ. When semen from bull born after 1991 were compared, types of semen were not significantly different in milk yield and milk protein, although type I was superior in milk fat, milk fat %, milk protein % and MFP and was significantly different from others. Moreover type Ⅲ and type Ⅳ was superior in UDC and were significantly different from others.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.5
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• pp.666-671
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• 2017

Objective: Aim of the current comparative study was to evaluate production outputs, reproduction efficiency and functional traits in dual-purpose Fleckvieh and Braunvieh cows, reared under temperate European conditions. Methods: A data-set from 414 Fleckvieh and 42 Braunvieh cows and 799 lactations was analysed. ID tag number, milk yield per milking session, number of steps/interval and milk conductivity were recorded and collected daily using AfiMilk 3.076 A-DU software (Afimilk Ltd., Kibbutz, Israel). Production and milk quality data were taken from the results of the official performance recordings and the reproductive outputs of cows were recorded by the research stations veterinarians. Comparisons between the two genotypes were carried out using the one way analysis of variance protocol, with categorical factor being considered the breed of cows. All the statistical inferences were carried out using Statistica software (StatSoft Inc., Tulsa, OK, USA). Results: Fleckvieh cows significantly outperformed ($p{\leq}0.05$) the Braunvieh herd, with average milk yields of $5,252.1{\pm}35.79kg$ and $4,897.6{\pm}128.94kg$, respectively. Age at first calving was significantly ($p{\leq}0.01$) influenced by the breed, with Fleckvieh heifers being more precocious ($32.8{\pm}0.29mo$) compared to those of Braunvieh breed ($35.7{\pm}0.84mo$). Reproduction efficiency as defined by the number of inseminations per gestation, calving interval, dystocia, days dry and days open, was not influenced by genotype (p>0.05). Incidences of sub-clinical mastitis, clinical mastitis, lameness and abortions were not influenced by the breed factor (p>0.05). Stay-ability of cows was significantly ($p{\leq}0.001$) influenced by genotype, with Braunvieh cows having an average age at culling of $117.88{\pm}11.78$ months compared to $90.88{\pm}2.89$ months in Fleckvieh. Conclusion: Overall, results have shown that genotype significantly influenced milk yield, age at first calving and longevity.

• Animal Bioscience
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• v.34 no.8
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• pp.1283-1289
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• 2021

Objective: The progestogen-associated endometrial protein (PAEP) gene encodes the main whey protein in milk, β-lactoglobulin. The aim of the study was to investigate polymorphism in the PAEP gene and its association with milk yield, composition, and quality. Methods: Test-day records for 782 dairy cows were analysed. A total of 10 single nucleotide polymorphisms (SNP) within the PAEP gene were investigated. The following parameters were recorded: milk yield (MY, kg/d), percent milk fat (%), protein (PP, %), dry matter (DMP, %) and lactose (LP, %), urea content (UC, mg/L) as well as natural logarithm for somatic cell count (LnSCC, ln). Effect on genomic estimated breeding values accuracy was evaluated with pedigree and single step model. Results: Results show that only three SNPs were polymorphic, creating 5 composite genotypes: P1 to P5. Differences in MY between composite genotypes were noted in the two tested herds. Cows with P5 composite genotypes were characterised by the highest PP and LnSCC and the lowest LP and UC (p<0.05). P4 was linked to an increased DMP and UC, while P3 to an increase in LP and decrease in PP and LnSCC. Both factors are important markers in herd management and have high influences on the herds economics. For 5 out of 7 traits the accuracy of prediction was improved by including the haplotype as a fixed effect. Conclusion: Presented results may suggest a new way to optimise breeding programmes and demonstrate the impact of using genomic data during that process.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.470-474
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• 1998

Data on the first lactation performance traits of $F_1$, $F_2$ and $F_3$ crosses covering the period from 1972 to 1995 of a total of 803 dairy cows of three genetic grades maintained at Livestock Production Research Farm, Indian Veterinary Research Institute, Izatnagar were analysed. Three genetic grades were 1/2 Friesian + 1/2 Hariana (FH), 1/2 Friesian + 1/4 Brown Swiss and 1/4 Hariana (FBH) and 1/2 Friesian+ 1/4 Jersey + 1/4 Hariana (FJH). Age at first calving increased by 7% and 8% in $F_2$ and $F_3$, respectively, over the $F_1$ in FH. The reduction in age at first calving at $F_2$ and $F_3$ levels by 2-7% over the $F_1$ was observed in FBH and FJH. The lactation milk yield of $F_1$, $F_2$ and $F_3$ crosses was $1,943{\pm}100.3$, $2202{\pm}120.5$ and $1,925{\pm}123.2kg$ in FH; $2,014{\pm}76.7$, $2,264{\pm}91.5$ and $2,096{\pm}123.9kg$ in FBH and $2,005{\pm}87.0$, $2,414{\pm}94.4$ and $2,093{\pm}121.1kg$ in FJH, respectively. The lactation milk yield improved by 12-20% in $F_2$ crosses in various genetic grades. The performance of $F_1$ was, however, maintained in FH $F_3$ crosses, it improved by 4% in FBH and FJH $F_3$ crosses. The lactation lengths and calving intervals were nearly the same for $F_1$, $F_2$ and $F_3$ crosses in FH while lactation lengths and calving intervals were reduced by 3-11% in $F_2$ and $F_3$ crosses in FBH and FJH genetic grades. The milk yield/day of lactation length and milk yield/day of calving interval increased by 16-35% in $F_2$ and 2-14% in $F_3$ over the $F_1$ in various genetic grades. It is recommended that a sufficiently large effective population size of these three genetic grades be maintained by inter se matings and rigorous selection of sires so for developing a genetic base population for new breed development.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.435-438
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• 1992

Data were collected on productive and reproductive performance of different $F_1$ crossbred cows (Deshi cows joined by A.I. to Sindhi, Sahiwal, Jersey or Holstein-Friesian Bull semen) reared by farmers in and around the Bangladesh Agricultural University campus at Mymensingh. The traits considered were birth weight, age at first heat, age at first calving, gestation length, post-partum heat period, milk yield, lactation length, dry period and calving interval. Data were analyzed statistically using a completely randomized design and Duncan's Multiple Range Test to compare and determine the significance of between individual group means. It was observed that the Holstein $\times$ Deshi had the highest birth weight (21.4 kg) followed by Sahiwal (17.6 kg), Jersey (16.7 kg) and Sindhi (16.1 kg). Shortest age at first heat (854 and 920 days) and age at first calving (1002 and 1201 days) were found for the Jersey $\times$ Deshi and Holstein $\times$ Deshi crosses respectively. The post-partum heat period were significantly different between breeds with Jersey and Holstein sired calves having the shortest intervals. There was no difference in the gestation length of the four crosses. Holstein $\times$ Deshi and Jersey $\times$ Deshi cows gave the highest milk yields due to longer lactation periods and higher daily milk production. Similarly, Holstein $\times$ Deshi and Jersey $\times$ Deshi crosses had significantly shorter dry periods and Jersey $\times$ Deshi had a shorter calving interval. From this study it may be concluded that exotic genotypes such as Holstein-Friesian and Jersey can perform very well under rural conditions in Bangladesh.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1379-1387
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• 2013

In a majority of mammals, male infants have heavier body mass and grow faster than female infants. Accordingly, male offspring nursing requires a much greater maternal energy contribution to lactation. It is possible that the maternal-fetal immunoendocrine dialog plays an important role in female preparation for lactation during pregnancy. Immune system genes are an integral part of gene regulatory networks in lactation and tumor necrosis factor alpha ($TNF{\alpha}$) is a proinflammatory cytokine that also plays an important role in normal mammary gland development. The aim of this study was to evaluate the influence of the sex of calf and/or the -824A/G polymorphism in the promoter region of $TNF{\alpha}$ gene on milk performance traits in Black Pied cattle over the course of lactation. We also studied the allele frequency differences of -824A/G variants across several cattle breeds, which were bred in different climatic conditions. The G allele frequency decreased gradually over the course of lactation events in the Black Pied dairy cattle because of a higher culling rate of cows with the G/G genotype (p<0.001). In contrast to the genotypes A/A and A/G, cows with G/G genotype showed significant variability of milk and milk fat yield subject to sex of delivered calf. Milk yield and milk fat yield were significantly higher in the case of birth of a bull calf than with a heifer calf (p<0.03). The G allele frequency varies from 48% to 58% in Grey Ukrainian and Black Pied cattle to 77% in aboriginal Yakut cattle. Our results suggest that the $TNF{\alpha}$-824A/G gene polymorphism may have an influence on the reproductive efforts of cows over the course of lactation events depending on the sex of progeny. Allocation of resources according to sex of the calf allows optimizing the energy cost of lactation. This may be a probable reason for high G allele frequency in Yakut cattle breeding in extreme environmental conditions. Similarly, the dramatic fall in milk production after birth of a heifer calf increases the probability of culling for the cows with the G/G genotype in animal husbandry.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.581-586
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• 1997

The present study analysed the various productive and reproductive characteristics of 1/2 Pabna Milking Cows (PMC)-1/2 Sahiwal (S) and 1/4 PMC-3/4 S collected from the Pabna milkshed area at Baghabarighat, Sirajgonj, Bangladesh. The studied traits were birth weight (BWT), age at puberty (AP), number of services per conception (NSC), post partum heat period (PPHP), gestation period (GP), daily milk yield (DMY), lactational production (LP), lactation length (LL), fat percentage and solids-not-fat percentage (SNFP). Five individual Sahiwal sires were used for the upgrading of Pabna Milking Cows. The used data covered from 1987 to 1994. Least-squares analysis of variance showed that genetic group had a significant effect on BWT (P < 0.05), AP (p < 0.01), DMY (p < 0.01), LP (p < 0.001), LL (p < 0.05), FP (p < 0.05) and SNFP (p < 0.01). Genetic group had non-significant effect on NSC, GP and PPHP. The effect of sire was significant on BWT (p < 0.01), NSC (p < 0.01), LP (p < 0.05) and LL (p < 0.05). The AP, NSC, DMY, LP, LL and SNFP were higher in 1/2 PMC-1/2S cows; BWT and PPHP were higher in 1/4 PMC-3/4S but GP and FP were almost same in both genetic groups. From this study it may be concluded that production and use of 1/2 PMC-1/2S would seem more profitable for commercial milk production in the Bangladesh Milk Producers' Cooperative Union Limited (BMPCUL) area and at the same time emphasis should be given on rigorous sire selection.