• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.613-619
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• 2005

Indigenous Yakutian cattle' adaptation to the hardest subarctic conditions makes them a valuable genetic resource for cattle breeding in the Siberian area. Since early last century, crossbreeding between native Yakutian cattle and imported Simmental and Kholmogory breeds has been widely adopted. In this study, variations at 22 polymorphic microsatellite loci in 5 populations of Yakutian, Kholmogory, Simmental, Yakutian-Kholmogory and Yakutian-Simmental cattle were analysed to estimate the genetic contribution of Yakutian cattle to the two hybrid populations. Three statistical approaches were used: the weighted least-squares (WLS) method which considers all allele frequencies; a recently developed implementation of a Markov chain Monte Carlo (MCMC) method called likelihood-based estimation of admixture (LEA); and a model-based Bayesian admixture analysis method (STRUCTURE). At population-level admixture analyses, the estimate based on the LEA was consistent with that obtained by the WLS method. Both methods showed that the genetic contribution of the indigenous Yakutian cattle in Yakutian-Kholmogory was small (9.6% by the LEA and 14.2% by the WLS method). In the Yakutian-Simmental population, the genetic contribution of the indigenous Yakutian cattle was considerably higher (62.8% by the LEA and 56.9% by the WLS method). Individual-level admixture analyses using STRUCTURE proved to be more informative than the multidimensional scaling analysis (MDSA) based on individual-based genetic distances. Of the 9 Yakutian-Simmental animals studied, 8 showed admixed origin, whereas of the 14 studied Yakutian-Kholmogory animals only 2 showed Yakutian ancestry (>5%). The mean posterior distributions of individual admixture coefficient (q) varied greatly among the samples in both hybrid populations. This study revealed a minor existing contribution of the Yakutian cattle in the Yakutian-Kholmogory hybrid population, but in the Yakutian-Simmental hybrid population, a major genetic contribution of the Yakutian cattle was seen. The results reflect the different crossbreeding patterns used in the development of the two hybrid populations. Additionally, molecular evidence for differences among individual admixture proportions was seen in both hybrid populations, resulting from the stochastic process in crossing over generations.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1708-1716
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• 2013

The objective of the trial was to study the relationship between the methane ($CH_4$) production and the Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrate fractions of feeds for cattle and the suitability of CNCPS carbohydrate fractions as the dietary variables in modeling the $CH_4$ production in rumen fermentation. Forty-five rations for cattle with the concentrate/roughage ratios of 10:90, 20:80, 30:70, 40:60, and 50:50 were formulated as feed samples. The Menke and Steingass's gas test was used for the measurement of $CH_4$ production. The feed samples were incubated for 48 h and the $CH_4$ production was analyzed using gas chromatography. Statistical analysis indicated that the $CH_4$ production (mL) was closely correlated with the CNCPS carbohydrate fractions (g), i.e. CA (sugars); $CB_1$ (starch and pectin); $CB_2$ (available cell wall) in a multiple linear pattern: $CH_4=(89.16{\pm}14.93)$ $CA+(124.10{\pm}13.90)$ $CB_1+(30.58{\pm}11.72)$ $CB_2+(3.28{\pm}7.19)$, $R^2=0.81$, p<0.0001, n = 45. Validation of the model using 10 rations indicated that the $CH_4$ production of the rations for cattle could accurately be predicted based on the CNCPS carbohydrate fractions. The trial indicated that the CNCPS carbohydrate fractions CA, $CB_1$ and $CB_2$ were suitable dietary variables for predicting the $CH_4$ production in rumen fermentation in vitro.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.5
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• pp.757-766
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• 2014

Postnatal muscle hypertrophy of beef cattle is the result of enhanced myofibrillar protein synthesis and reduced protein turnover. Skeletal muscle hypertrophy has been studied in cattle fed ${\beta}$-adrenergic agonists (${\beta}$-AA), which are receptor-mediated enhancers of protein synthesis and inhibitors of protein degradation. Feeding ${\beta}$-AA to beef cattle increases longissimus muscle cross-sectional area 6% to 40% compared to non-treated cattle. The ${\beta}$-AA have been reported to improve live animal performance, including average daily gain, feed efficiency, hot carcass weight, and dressing percentage. Treatment with ${\beta}$-AA increased mRNA concentration of the ${\beta}_2$ or ${\beta}_1$-adrenergic receptor and myosin heavy chain IIX in bovine skeletal muscle tissue. This review will examine the effects of skeletal muscle and adipose development with ${\beta}$-AA, and will interpret how the use of ${\beta}$-AA affects performance, body composition, and growth in beef cattle.

• Korean Journal of Organic Agriculture
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• v.28 no.2
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• pp.171-188
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• 2020

The Coronavirus disease (COVID-19), first identified in China in December 2019, has widely spread worldwide and is an ongoing pandemic. It is expected that the ripple effect of COVID-19 on the global economy including the agricultural sector will increase substantially if not properly controlled shortly. This study examines the potential impact of COVID-19 on the Korean beef cattle sector and farm labor demand for Korean beef cattle using a dynamic partial equilibrium model. The agricultural production value and farm labor demand for Korean beef cattle in the scenario assuming pessimistic GDP growth rate (-1.2% in 2020) with no direct supply shocks fell by up to 4.00% and 0.67%, respectively, compared to the baseline which represents the future without COVID-19 outbreak. On the other hand, the agricultural production value and farm labor demand for Korean beef cattle in the scenario assuming both pessimistic GDP growth rate and supply shocks (-12.7% beef imports and + 2.4% feed cost in 2020) increased by up to 12.08% and 1.99%, respectively, compared to the baseline.

• Animal Bioscience
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• v.34 no.5
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• pp.914-921
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• 2021

Objective: The objective of this study was to compare growth performance, carcass traits and meat quality in young bulls, steers and heifers produced by crossing Limousin bulls with Holstein-Friesian cows, fattened semi-intensively and slaughtered at 18 months of age. Methods: Thirty-one young calves were reared in a conventional production system, and were fed milk replacer, hay and concentrate. At 6 months of age, the animals were divided into groups based on gender, and were fed a total mixed ration composed of grass silage, concentrates I and II in a semi-intensive production system. At the end of the fattening period (18 months), the animals were slaughtered, carcass quality was evaluated, and samples of musculus longissimus thoracis were collected to determine the proximate composition and quality of meat. Results: Bulls were characterized by the highest percentage share of the most valuable cuts in the carcass, and three-rib sections from bull carcasses had the highest lean meat content with low intramuscular fat content (0.93%). No significant differences in carcass conformation, dressing percentage or the percentage share of round in the right half-carcass were found between bulls vs. steers and heifers. Heifers and steers had higher carcass fat content than bulls, which had a positive influence on the sensory properties of beef. In comparison with the meat of bulls, the meat of steers and heifers was characterized by more desirable physical properties and sensory attributes (water-holding capacity, shear force, color lightness, aroma, juiciness, tenderness, flavor). Conclusion: Under the semi-intensive production system, heifers and steers had higher carcass fat content than bulls, which had a positive effect on the sensory properties of beef. Bulls are better suited for intensive systems, which contribute to improving the quality of their meat. The results of this study may encourage producers to breed steers and heifers for beef.

• Journal of Animal Science and Technology
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• v.60 no.12
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• pp.31.1-31.10
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• 2018

Background: Research on loci influencing milk production traits of dairy cattle is one of the main topics of investigation in livestock. Many genomic regions and polymorphisms associated with dairy production have been reported worldwide. In this context, the purpose of this study was to identify candidate loci associated with milk yield in Argentinean dairy cattle. A database of candidate genes and single nucleotide polymorphisms (SNPs) for milk production and composition was developed. Thirty-nine SNPs belonging to 22 candidate genes were genotyped on 1643 animals (Holstein and Holstein x Jersey). The genotypes obtained were subjected to association studies considering the whole population and discriminating the population by Holstein breed percentage. Phenotypic data consisted of milk production values recorded during the first lactation of 1156 Holstein and 462 Holstein ${\times}$ Jersey cows from 18 dairy farms located in the central dairy area of Argentina. From these records, 305-day cumulative milk production values were predicted. Results: Eight SNPs (rs43375517, rs29004488, rs132812135, rs137651874, rs109191047, rs135164815, rs43706485, and rs41255693), located on six Bos taurus autosomes (BTA4, BTA6, BTA19, BTA20, BTA22, and BTA26), showed suggestive associations with 305-day cumulative milk production (under Benjamini-Hochberg procedure with a false discovery rate of 0.1). Two of those SNPs (rs43375517 and rs135164815) were significantly associated with milk production (Bonferroni adjusted p-values < 0.05) when considering the Holstein population. Conclusions: The results obtained are consistent with previously reported associations in other Holstein populations. Furthermore, the SNPs found to influence bovine milk production in this study may be used as possible candidate SNPs for marker-assisted selection programs in Argentinean dairy cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.4
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• pp.263-267
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• 1990

The fat thicknesses of twenty-eight Japanese Black beef steers were measured with an ultrasonic device at eleven points on the cattle prior to slaughter and side dissection. The relation between live fat thickness and both weight and percentage of fat and lean in the carcass was examined. Fat thickness obtained from nine points of the chest, flank and rump regions was found to relate significantly (P<0.01) to both weight and percentage of fat. However, shoulder fat thickness measurements were not significantly related to the weight or percentage of fat or lean in the carcass. Addition of live fat thickness to animal age or live weight as an independent variable markedly improved the precision of multiple regression equations for predicting weight of fat and lean, and percentage of fat. In predicting the percentage of lean, both animal age and body weight were not employed in the multiple regression equation. The residual standard deviation for predicting percentage of fat and lean were 1.93 and 1.87, respectively. The ultrasonic measurement of fat thickness if supposed to be useful to the prediction of carcass composition of beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.57-71
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• 2009

Crop-livestock mixed farming systems depend on the efficiency with which nutrients are conserved and recycled. Home-grown forage is used as animal feed and animal excretions are applied to cultivated crop lands as manure. The objective of this study was to develop a mixed farming system model for dairy cattle in Japan. The model consisted of four sub-models: the nutrient requirement model, based on the Japanese Feeding Standards to determine requirements for energy, crude protein, dry matter intake, calcium, phosphorus and vitamin A; the optimum diet formulation model for determining the optimum diets that satisfy nutrient requirements at lowest cost, using linear programming; the herd dynamic model to calculate the numbers of cows in each reproductive cycle; and the whole farm optimization model to evaluate whole farm management from economic and environmental viewpoints and to optimize strategies for the target farm or system. To examine the model' validity, its predictions were compared against best practices for dairy farm management. Sensitivity analyses indicated that higher yielding cows lead to better economic results but higher emvironmental load in dairy cattle systems integrated with forage crop production.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1247-1253
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• 2003

Selection for increased milk production in dairy cows has often resulted in a higher incidence of disease and thus incurred a greater health costs. Considerable interests have been shown in breeding dairy cattle for disease resistance in recent years. This paper discusses the limitations of breeding dairy cattle for genetic resistance in six parts: 1) complexity of disease resistance, 2) difficulty in estimating genetic parameters for planning breeding programs against disease, 3) undesirable relationship between production traits and disease, 4) disease as affected by recessive genes, 5) new mutation of the pathogens, and 6) variable environmental factors. The hidden problems of estimating genetic and phenotypic parameters involving disease incidence were examined in terms of categorical nature, non-independence, heterogeneity of error variance, non-randomness, and automatic relationship between disease and production traits. In light of these limitations, the prospect for increasing genetic resistance by conventional breeding methods would not be so bright as we like. Since the phenomenon of disease is the result of a joint interaction among host genotype, pathogen genotype and environment, it becomes essential to adopt an integrated approach of increasing genetic resistance of the host animals, manipulating the pathogen genotypes, developing effective vaccines and drugs, and improving the environmental conditions. The advances in DNA-based technology show considerable promise in directly manipulating host and pathogen genomes for genetic resistance and producing vaccines and drugs for prevention and medication to promote the wellbeing of the animals.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.465-474
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• 2010

The effects of four types of tropical protein-rich trees on nutrient digestibility, nitrogen (N) balance, urinary purine derivative (PD) excretion and blood metabolites in four Thai Brahman cattle (290${\pm}$2.5 kg) were studied. The animals were fed twice daily, with each feeding consisting of 1 kg (fresh weight) rice straw and one of the four dietary supplements: i) 1.98 kg oven-dried rain tree pods (RTP) and 20 g premix (RTPP), ii) 980 g RTP and 1 kg sun-dried leucaena leaves and 20 g premix (LLRT), iii) 980 g RTP and 1 kg sun-dried cassia leaves and 20 g premix (CLRT) and iv) 980 g RTP and 1 kg sun-dried mulberry leaves and 20 g premix (MLRT). The apparent dry matter (DM) and organic matter (OM) digestibilities were higher (p<0.05) in cattle fed the CLRT supplement than in those fed the other supplements, whilst the apparent digestibility of neutral detergent fibre (NDF) was higher (p<0.05) in cattle fed the CLRT and MLRT supplements than in those fed the other supplements. The N-balance of cattle fed LLRT and CLRT supplements was higher (p<0.05) than in cattle fed RTPP and MLRT supplements, whilst the apparent digestibility of N was highest (p<0.05) in cattle fed RTPP supplement, compared to the other supplements. Allantoin and PD excretion in the urine, and the ratios of allantoin/DOMI and PD/DOMI were higher (p<0.05) in cattle fed RTPP and MLRT than for those fed LLRT and CLRT supplements. Plasma ${\beta}$-hydroxy butyrate (${\beta}$-HBA) and insulin concentrations were higher (p<0.05) in cattle fed RTPP supplement than in those fed the other supplements. The study demonstrated the value of using local multipurpose trees (MPTs) to improve Brahman cattle feeding systems in the tropics.