• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.61-66
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• 1993

Sixteen Korean native bulls weighing about 211 kg were randomly allotted to investigate the effect of different dietary calcium levels on performance. Feeding period was divided into growing period and fattening period for 180 days. Four calcium levels (0.44, 0.58, 0.72 and 0.86%) were used to each period. Bulls fed the diet containing 0.72% calcium had greater body weight gain and consumed more feed than bulls fed diets containing 0.44, 0.58 and 0.86% calcium and improved in feed efficiency. Bulls fed the diet containing 0.44% calcium were worst in performance. It can be concluded that Korean native bulls in growing and fattening period required no more than 0.72% calcium in diet that contained 0.55% phosphorus, and appeared that when ratio of calcium to phosphorus intake was 1.45, performance of Korean native bulls was most beneficial.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.416-421
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• 1997

The effect of imported young bulls on the genetic progress was examined in the Holstein dairy cattle population in Japan. The effect of the difference of mean genetic merit between imported and domestic young bulls ("genetic difference") was recognized on the genetic progress of the domestic animals in the early stage of selection. On the other hand, the genetic progress of domestic animals were remarkably influenced by the genetic trend of imported young bulls ("genetic trend") in the later stage. Import of young bulls originated from high genetic level of young bulls originated from high genetic level population improved the genetic progress of domestic population. But, the increase of the immigration ratio of imported young bulls ("immigration ratio") did not influence linearly on the progress of the genetic merit of domestic animals. Even if "immigration ratio" was 100%, the genetic merit of domestic animals could not overcome the one of imported young bulls. In the later stage of selection, the genetic merit of domestic animals ran parallel to those of imported young bulls.

• Animal Bioscience
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• v.36 no.1
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• pp.63-74
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• 2023

Objective: The objective of this study was to investigate the effects of feeding active dry yeast (ADY) and yeast culture (YC) on fecal bacterial community in finishing bulls fed high-concentrate diets in the same experimental environment. Methods: Forty-five healthy finishing cattle (Simmental×Chinese Luxi yellow bulls; 24 months; 505±29 kg) were randomly divided into three groups: i) CON group (control group, only fed basal diet), ii) ADY group (fed basal diet + active dry yeast), and iii) YC group (fed basal diet + yeast culture). At the end of the trial, nine rectum fecal samples were randomly selected from each group for bacterial DNA sequencing. Results: There was no difference among groups about alpha diversity indices (all p>0.05), including ACE, Chao 1, Shannon, and Simpson indices. Principal component analysis and non-metric multidimensional scaling analysis showed a high similarity among three groups. Compared with CON group, ADY and YC groups had greater relative abundance of c_Clostridia, o_Oscillospirales, and f_Oscillospiraceae, but lesser relative abundance of g_Megasphaera, and s_Megasphaera_elsdenii (all p<0.01). And, the relative abundances of p_Firmicutes (p = 0.03), s_Prevotella_sp (p = 0.03), o_Clostridiales (p<0.01), g_Clostridium (p<0.01), f_Caloramatoraceae (p<0.01), and f_Ruminococcaceae (p = 0.04) were increased in the ADY group. The PICRUSt2 prediction results showed that the metabolic pathways had no significant differences among groups (p>0.05). Besides, the relative abundance of c_Clostridia (r = 0.42), and f_Oscillospiraceae (r = 0.40) were positively correlated to average daily gain of finishing bulls (p<0.05). Conclusion: Both of ADY and YC had no effect on diversity of fecal bacteria in finishing bulls, but the supplementation of ADY and YC can improve the large intestinal function in finishing bulls by increasing the abundance of cellulolytic bacteria and altering the abundance of lactic acid-utilizing bacteria.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.1059-1066
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• 2008

This study was carried out to investigate the effects of dietary sulfur (S) and vitamin E (Vit E) supplementation on the quality of beef from longissimus muscle of Hanwoo bulls. Eleven, 29 months-aged Hanwoo bulls were randomly divided into three feed supplementation groups (S (n = 4), Vit E (n = 4) and S+Vit E (n = 3)). S was given as much as 12 g/head/d and Vit E was given as much as 1,200 IU/head/d; both supplements were given for 3 months prior to slaughter. At 24 h post-slaughter, the carcasses were weighed and evaluated by official grader for carcass traits. At 48 h post-slaughter, the M. longissimus from each carcass was collected and stored at $4{\pm}0.2^{\circ}C$ for 10 days. There were no significant differences in yield and quality grades of carcass and proximate composition, physical properties and aroma pattern of meat among all groups. At 5 days of storage, the TBARS value of meat from cattle with S+Vit E supplementation was significantly lower (p<0.05) than other groups; and at 10 days of storage, the TBARS value of meat from cattle with Vit E and S+Vit E supplementations was significantly lower (p<0.05) than from cattle with S supplementation. At 5 days of storage, MetMb concentration of meat from cattle with S+Vit E supplementation was significantly lower (p<0.05) than from cattle with Vit E supplementation; and at 10 days of storage, MetMb concentration of meat from cattle with S+Vit E supplementation was significantly lower (p<0.05) than from other groups. At 10 days of storage, the redness value of meat from cattle with S supplementation was significantly higher (p<0.05) than from cattle with Vit E supplementation and the hue-angle value of meat from cattle with S and S+Vit E supplementations was significantly lower (p<0.05) than from cattle with Vit E supplementation. Dietary Vit E supplementation had a better effect on lipid stability whereas dietary S supplementation had a better effect on OxyMb stability. The dietary combination of S and Vit E created the highest protection for beef from myoglobin oxidation and thus improved the color stability of meat.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.550-556
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• 2009

Two experiments were carried out to investigate the relationship of slaughter age and carcass traits of Hanwoo cattle. A total number of 11,284 heads of cattle (4,624 bulls, 6,120 steers, and 540 females) were used in the experiment (Exp.) 1. In the Exp. 2, 3,887 heads of steers slaughtered at age of 24-36 mon were used. After 24 h post-slaughter chilling, the carcasses were weighed and evaluated by an official grader of carcass traits according to the Korean carcass grading standard. Backfat thickness was the main variable in yield index and grade whereas marbling score was the main variable in carcass quality grade. Meat color was an important factor affecting carcass quality grade of bulls; fat color was an important factor affecting those of steers and females; and maturity was an important factor affecting that of females. After 24-mon-old, extension of slaughter age did not automatically increase the quantity and quality of meat. However, 29 mon of age can be regarded as the optimum time to slaughter steers to attain the highest take home money for farmers.

• Parasites, Hosts and Diseases
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• v.41 no.3
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• pp.141-145
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• 2003

This study was performed to investigate the prevalence of theileriosis and to compare the prevalence of this disease in Korean native cattle reared under different environmental conditions, namely, in a grazing area and a non-grazing area by polymerase chain reaction. Three hundred and one Korean native cattle (276 cows and 25 bulls) that had not received prior treatment or been vaccinated to prevent theileriosis were examined by PCR for Theileria sergenti infection from 2001 to 2002. In our study, the parasitemia range in T. sergenti-positive cattle by microscopy were from 0.1 to 3％ (mean 0.8％). In terms of mean prevalence, 204 of the 301 Korean native cattle (67.8％) were positive reaction by PCR. Our results also revealed that the infection rate among cows (70.3％) was significantly higher than that among bulls (40.0％) (p < 0.01). T. sergenti infection among the over 3 year-old-group (75％) had a significant higher prevalence than that among the less than 3 year-old-group (61.8％) (p < 0.05). Our data also showed that grazing areas (76.1％) had the significant higher prevalence than non-grazing areas (51％) (p < 0.001). In conclusion, this study demonstrates that the prevalence of T. sergenti infection is high and that its prevalence in grazing cattle is higher than that in non-grazing cattle, Therefore, life-long treatment and the development of an optimal vaccine are needed to reduce the numbers of bovine theileriosis in both grazing and non-grazing areas.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.4
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• pp.548-555
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• 2019

Objective: The main objective of this study was to evaluate the effect of different feeding levels of a total mixed ration silage-based diet on feed intake, total tract digestion, enteric methane emissions, and energy partitioning in two beef cattle genotypes. Methods: Six mature bulls (three Thai natives, and three Thai natives - Charolais crossbreeds) were assigned in a replicated $3{\times}3$ Latin square design, with cattle breed genotype in separate squares, three periods of 21 days, and three energy feeding above maintenance levels (1.1, 1.5, and 2.0 MEm, where MEm is metabolizable energy requirement for maintenance). Bulls were placed in a metabolic cage equipped with a ventilated head box respiration system to evaluate digestibility, record respiration gases, and determine energy balance. Results: Increasing the feeding level had no significant effect on digestibility but drastically reduced the enteric methane emission rate (p<0.05). Increasing the feeding level also significantly increased the energy retention and utilization efficiency (p<0.01). The Thai native cattle had greater enteric methane emission rate, digestibility, and energy utilization efficiency than the Charolais crossbred cattle (p<0.05). The daily metabolizable energy requirement for maintenance in Thai native cattle ($388kJ/kg\;BW^{0.75}$, where $BW^{0.75}$ is metabolic body weight) was 15% less than that in Charolais crossbred cattle ($444kJ/kg\;BW^{0.75}$). Conclusion: Our results suggested that the greater feeding level in zebu beef cattle fed above maintenance levels resulted in improved energy retention and utilization efficiency because of the reduction in enteric methane energy loss. The results also indicated higher efficiency of metabolisable energy utilization for growth and a lower energy requirement for maintenance in Bos indicus than in Bos taurus.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.128-132
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• 1998

The relative disappearance and rate of degradation of dry matter (DM) and neutral detergent fiber (NDF) of nine different feedstuffs were determined by simultaneously suspending groups of substrates, using the nylon bags, in the rumen of males of Sahiwal cattle and Nili-Ravi buffalo. The digestion kinetics of leguminous forages (Lucerne, berseem and cowpeas) and feed byproducts (cotton seed cake, wheat bran and wheat straw) did not differ between the two species. However, the DM and NDF digestibilities and rates of digestion of grasses and wheat straw were greater in buffalo than in cow bulls, indicating that buffaloes are better converters of poor quality roughages than are Sahiwal. The lag time for DM of grasses did not differ between these two species but the NDF lag time was lower in buffalo than in cows, indicating that both the rate and lag time of digestion may be reliable indicators for assessing the NDF quality.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.6
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• pp.759-767
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• 2016

The aim of this study was to compare two random regression models (RRM) fitted by fourth ($RRM_4$) and fifth-order Legendre polynomials ($RRM_5$) with a lactation model (LM) for evaluating Holstein cattle in Brazil. Two datasets with the same animals were prepared for this study. To apply test-day RRM and LMs, 262,426 test day records and 30,228 lactation records covering 305 days were prepared, respectively. The lowest values of Akaike's information criterion, Bayesian information criterion, and estimates of the maximum of the likelihood function (-2LogL) were for $RRM_4$. Heritability for 305-day milk yield (305MY) was 0.23 ($RRM_4$), 0.24 ($RRM_5$), and 0.21 (LM). Heritability, additive genetic and permanent environmental variances of test days on days in milk was from 0.16 to 0.27, from 3.76 to 6.88 and from 11.12 to 20.21, respectively. Additive genetic correlations between test days ranged from 0.20 to 0.99. Permanent environmental correlations between test days were between 0.07 and 0.99. Standard deviations of average estimated breeding values (EBVs) for 305MY from $RRM_4$ and $RRM_5$ were from 11% to 30% higher for bulls and around 28% higher for cows than that in LM. Rank correlations between RRM EBVs and LM EBVs were between 0.86 to 0.96 for bulls and 0.80 to 0.87 for cows. Average percentage of gain in reliability of EBVs for 305-day yield increased from 4% to 17% for bulls and from 23% to 24% for cows when reliability of EBVs from RRM models was compared to those from LM model. Random regression model fitted by fourth order Legendre polynomials is recommended for genetic evaluations of Brazilian Holstein cattle because of the higher reliability in the estimation of breeding values.

• Journal of Animal Science and Technology
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• v.51 no.2
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• pp.105-110
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• 2009

The Objective of this study was to compare performances of proven and young holstein bulls bred in Korea. Proven bulls are categorized into the imported and the korean ones. Data from 148,329 heads of daughters of 1,128 bulls from 1990 to 2004 were used in this study. Proven bulls showed higher milk yield than young bulls in same year. Young bulls, however, always yielded more milk than korean bulls when proven bulls were categorized into the imported and the korean ones. Hence, it was proven that dairy bull selection program had properly been functioned in Korea. Selected bulls, which were korean proven bulls and young bulls, yielded higher milk fat than imported bulls as the selection was weighted on the yield of the milk fat. This comparison was based on the performances of daughters without the consideration of the semen price. Semen price of the imported proven bulls were higher than the korean proven bulls and the semen of young bulls was free. Hence, the performances of korean bulls with the consideration of the preferential effect would be much higher than others, and further studies are necessary.