Increase in plasma total antioxidant capacity of grazing Japanese Black heifers and cows in forestland in Japan

Blood total antioxidant capacity (TAC) has become a key bio‐marker for animal health. Forest‐grazing cattle are known to forage various native plants that have high TAC. This study evaluated differences of plasma TAC between forest‐grazing (FG) and pasture‐grazing cattle (PG). Experiment 1 monitored the plasma TAC levels of 32 Japanese Black cattle. The level in PG did not change throughout the grazing period. However, that in FG, which increased from summer, was significantly higher than that in PG through fall (P < 0.05). In experiment 2, we used nine Japanese Black heifers and investigated their blood antioxidant parameters and the TAC in plants that the cattle consumed in late June and September. The plasma TAC levels in FG were significantly higher than those in PG in both periods (P < 0.05). Plasma levels of lipid peroxidation in FG tended to be lower than that in PG (P = 0.098). Furthermore, the TAC levels in various species of shrubs and trees consumed by FG were higher than those in pasture grasses. Results of this study show that plasma TAC of grazing Japanese Black cattle in forestland increase from summer through fall.     

Comparison of plasma metabolite concentrations and enzyme activities in beef cattle raised by different feeding systems in Korea, Japan and New Zealand

Concentrations of metabolites and immunoreactive insulin (IRI) and activities of enzymes related to energy metabolism were measured in plasma of Korean and Japanese beef cattle, which were raised by the indoor feeding system programmed to feed larger amount of roughage in their growing periods and larger amount of concentrate diet in their finishing periods (Japanese feeding system), and grazing New Zealand beef cattle. By the Japanese beef grading system, Korean and Japanese beef cattle showed high beef quality score, average grade 3.3 and 3.6, respectively. The plasma free fatty acid and lactate concentrations and lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and aspartate aminotransferase (AST) activities in Korean beef cattle were significantly higher than those in Japanese beef cattle. The plasma lactate concentration in Korean beef cattle was 8.40 mmol/l, which was similar to the values observed in lactic acidosis. The higher activities of plasma LDH, MDH and AST may indicate slight liver damage by slightly acidotic conditions in Korean beef cattle. New Zealand beef cattle fed on pasture which they harvest by grazing showed significantly lower plasma glucose, cholesterol, lactate and IRI concentrations and enzyme activities than those in Korean and Japanese beef cattle fed on larger amount of concentrate diets. Plasma metabolite concentrations and energy metabolism-related enzyme activities may be good indicators for evaluating metabolic conditions of beef cattle raised by different feeding systems.     

Nutritional parameters in the blood of dams during late gestation and immediately after calving,in the umbilical vein at calving,and in the blood of calves immediately following birth in Holstein heifers pregnant with either Holstein or beef breed fetuses

Dairy cattle management lacks consideration of fetal breed, the effect of which on fetal growth and nutrition are unclear. We investigated blood parameters in 12 late-pregnant Holstein heifers with similar (Holstein, n = 5) or different (Japanese Black [n = 4] or F1 cross [n = 3]; Holstein × Japanese Black) fetus breeds and in their umbilical cords and calves. Samples were obtained from dams 1 week before calving (−1 week) and immediately after calving, from the umbilical vein at calving, and from calves immediately after birth. Dams with beef fetuses had higher serum glucose levels (−1 week; p < .05) than those with Holstein fetuses. Plasma total amino acid, total essential amino acid, total nonessential amino acid, and other amino acid concentrations were lower in the umbilical veins of dams with calves of the beef breeds than in those of the Holstein breeds (p < .05). Furthermore, serum glucose and plasma amino acid levels were lower in the beef calves than in the Holstein calves (p < .05). Overall, nutrient supply from dams to beef fetuses was lower than that to Holstein fetuses. Our findings may facilitate feeding management of dairy cattle pregnant with beef breeds for appropriate fetal growth and nutrition.     

Effects of low and high levels of maternal nutrition consumed for the entirety of gestation on the development of muscle,adipose tissue,bone, and the organs of Wagyu cattle fetuses

This study aimed to investigate the effects of high and low levels of energy intake during the entire gestation period on the skeletal muscle development, organ development, and adipose tissue accumulation in fetuses of Wagyu (Japanese Black) cows, a breed with highly marbled beef. Cows were allocated to a high-nutrition (n = 6) group (fed 120% of the nutritional requirement) or low-nutrition (n = 6) group (fed 60% of the nutritional requirement). The cows were artificially inseminated with semen from the same sire, and the fetuses were removed by cesarean section at 260 ± 8.3 days of fetal age and slaughtered. The whole-body, total muscle, adipose, and bone masses of the fetal half-carcasses were significantly higher in the high-nutrition group than the low-nutrition group (p = 0.0018, 0.009, 0.0004, and 0.0362, respectively). Fifteen of 20 individual muscles, five of six fat depots, nine of 17 organs, and seven of 12 bones that were investigated had significantly higher masses in the high-nutrition group than the low-nutrition group. The crude components and amino acid composition of the longissimus muscle significantly differed between the low- and high-nutrition groups. These data indicate that maternal nutrition during gestation has a marked effect on the muscle, bone, and adipose tissue development of Wagyu cattle fetuses.     

Thermal balance of cattle grazing winter range: model application

Beef cattle grazing semiarid foothill rangeland of the Northern Rockies during winter may be exposed to cold temperatures and high winds while grazing pastures with low nutritional value. Cattle can physiologically and behaviorally respond to the changing environment to lower their metabolic requirements and reduce the effects of cold exposure. Requirements of grazing cattle may be overpredicted with models developed in controlled settings that do not account for energy-conserving behaviors. We refined a simple thermal balance equation to model heat exchange of free-ranging cattle. We accounted for the complex interactions between animal behavior and the changing natural environment by applying the insulation characteristics of the cattle's tissue and coat to a simple geometric shape of an asymmetric ellipsoid at different orientations to the sun and wind. We compared the model predictions with heat production measured in 3 studies, and in all cases the model predictions were similar to those reported. Model simulations indicate behaviors, such as lying and orientation to the sun, mitigated the effects of extreme weather. For many combinations of winter weather variables, metabolic requirements increased only slightly due to cold exposure of mature beef cattle in a near-maintenance state. The results indicate that solar radiation contributes strongly to the thermal balance of a cow. Thus, previous models that do not account for the irradiative environment may overestimate metabolic requirements of cattle acclimated to grazing winter range.     

Genomic imprinting variances of beef carcass traits and physiochemical characteristics in Japanese Black cattle

The objective of this study was to estimate variance components related to imprinting for carcass traits and physiochemical characteristics in Japanese Black cattle. The carcass records obtained from 4,220 Japanese Black feedlot cattle included carcass weight (CW), rib eye area (REA), rib thickness, subcutaneous fat thickness, and beef marbling score (BMS), and the physiochemical characteristics were fat, moisture, glycogen per proportion of moisture content, oleic acid, and monounsaturated fatty acids (MUFA). To detect gametic effects, an imprinting model was fitted. High additive heritabilities were estimated for all traits (from 0.516 for glycogen to 0.853 for fat) and were reduced in Mendelian heritability. The range of the differences was from 0.002 (CW) to 0.331 (fat and moisture), and the reductions were due to their imprinting variances. The ratio of the imprinting variance to the total additive genetic variance for REA (0.374), BMS (0.291), fat (0.387), moisture (0.388), and MUFA (0.337) were large (p < 0.05). These imprinting variances were due to the maternal contribution and suggested the existence of maternally expressed genomic imprinting effects on the traits in Japanese Black cattle. Therefore, maternal gametic effects should be considered in breeding programs for Japanese Black cattle.     

Conception rate of Holstein and Japanese Black cattle following embryo transfer in southwestern Japan

This study aimed to quantify and compare conception rates to embryo transfer (ET) of Holstein and Japanese Black cattle in southwestern Japan. A 10‐year retrospective epidemiological survey was conducted. The recipient numbers for Holstein and Japanese Black cattle was 621 and 527, respectively. Conception rates of Holstein and Japanese Black cattle during the study period were 45.4% and 42.3%, respectively. There was no significant difference between both breeds. However, a different trend of conception rate to ET in Holstein and Japanese Black cattle was observed. In Holstein cattle, conception rate in August to October was lower than in the other months and was significantly lower (p < .05) than in April. Particularly, conception rate in October of Holstein cattle was the lowest (31.0%). In Japanese Black cattle, conception rates in December (24.2%) and January (31.3%) were lower than in the other months. Conception rate of Japanese Black cattle declined as the temperature–humidity index (THI) decreased, exhibiting significantly lower levels in the ≤45 THI class than in any other THI class (p < .05). By contrast, in Holstein cattle, no relationship was observed between conception rate and THI on the day of ET. These observations suggest the importance of appropriate management that considers seasonal reactivity in each breed.     

Microarray analysis of Longissimus thoracis muscle gene expressions in vitamin A‐restricted Japanese Black steers in middle fattening stage

Vitamin A (VA) restriction in beef cattle improves meat marbling; however, the underlying molecular mechanisms remain incompletely understood. We performed microarray analysis to clarify the effect of VA restriction on Longissimus thoracis gene expressions in Japanese Black steers. Six Japanese Black steers 13–14 months of age were divided into two groups: S group (n = 3), which received VA supplementation, and R group (n = 3), in which dietary VA intake was restricted. Steers were fattened for 7 months, following which tissue samples were obtained. Extracted RNA samples were analyzed by Affymetrix Genechip Bovine Genome Array. Lists of genes highly expressed in the R and S groups were obtained. The lists were functionally interpreted using functional annotation software, DAVID. In the R and S groups, 48 and 40 genes were significantly highly expressed, respectively. The gene list of the R group included CD36, LPL, GPAM, DGAT2, and SCD and additional genes annotated ‘PPAR signaling pathway,’ ‘lipid biosynthesis’ and ‘mitochondrion,’ whereas that of the S group included COL1A2, FN1 and DCN and additional genes annotated ‘extracellular matrix.’ Changes in the expression of these genes are possibly involved in marbling improvement in beef cattle by VA restriction.     

UTS2R gene polymorphisms are associated with fatty acid composition in Japanese beef cattle

Fatty acid composition of beef adipose tissue is one of its important traits because a high proportion of monounsaturated fatty acid is related to favorable beef flavor and tenderness. In this study, we searched polymorphisms in full length coding DNA sequence of urotensin 2 recepter and investigated the effects on fatty acid composition (C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, monounsaturated fatty acid, saturated fatty acid). Eight single nucleotide polymorphisms (SNP) were identified by sequence comparison among eight animals, including five Japanese Black and three Holstein cattle. One of these SNP (c.866C>T) was predicted to cause amino acid substitutions (P289L) and the other seven synonymous SNP, including c.267C>T, were presumed to be in linkage disequilibrium. Therefore we selected two SNP (c.267C>T and c.866C>T) for further analysis. We investigated associations between these genotypes and fatty acid composition in three Japanese Black populations (n = 560, 245 and 287) and a Holstein population (n = 202). Tukey‐Kramer's honestly significant difference test revealed that CC genotype in c.267C>T indicated lower C14:0 and higher C18:1 than the other genotypes in Japanese Black cattle and CC genotype in c.866C>T showed lower C16:1 than CT genotype in Holstein cattle (P < 0.05). These results suggested that these genotypes would contribute to production of high‐grade meat as selection markers in beef cattle.     

慢性冷热应激对放牧西门塔尔牛抗氧化功能及HPA轴、SAM轴激素分泌的影响

为研究慢性冷热应激对放牧条件下西门塔尔牛生理指标、抗氧化功能及下丘脑-垂体-肾上腺皮质轴(HPA)、交感-肾上腺-髓质轴(SAM)激素分泌的影响,选取内蒙古锡林郭勒盟苏尼特左旗某家庭牧场体质量相近、体况健康的西门塔尔牛20头,试验期间测定试验牛生理指标,于试验期最后一天清晨进行颈静脉采血并制备血清,采用ELISA方法检...     

Development of discrimination markers between Japanese domestic and imported beef

In the meat industry, correct labeling of beef origins or breed is required to assure quality and safety. This paper describes the development of discrimination markers between Japanese domestic and imported beef from the United States (US) and Australia (AUS) based on a bovine 50K single nucleotide polymorphism (SNP) array using a total of 110 samples: Japanese Black (n = 50), Japanese Holstein (n = 50) and US cattle (n = 10). Genotyping information revealed 1081 SNPs as candidate markers that were polymorphic only in US cattle. The genotyping results by PCR – restriction length polymorphism in Japanese Black (n = 300) and Holstein cattle (n = 146) revealed that 11 SNPs had alleles specific to US cattle. Their allelic frequencies in US cattle (n = 108) ranged from 0.097 to 0.250 with an average of 0.178 and the combined identification probability of US cattle was 0.987. In addition, we also verified the applicability of these US‐specific markers to AUS cattle. Their allelic frequencies in AUS cattle (n = 280) ranged from 0.063 to 0.224 with an average of 0.137 and the combined identification probability of AUS cattle was 0.963. In conclusion, a set of these markers could be useful for discriminating between Japanese domestic and imported beef and would contribute to identify origins and prevent falsified labeling of beef.     

Provision of beta‐glucan prebiotics (cellooligosaccharides and kraft pulp) to calves from pre‐ to post‐weaning period on pasture

We conducted two feeding experiments to evaluate the effects of supplementation with either cellooligosaccharide or kraft pulp on growth performance in grazing beef calves (Japanese Black) from 4 weeks pre‐weaning to 12 to 16 weeks post‐weaning. In Experiment 1 (20‐week duration), nine calves (2.9‐month‐old females) were assigned to either a control group (CON) or an experimental group (CEL) fed cellooligosaccharide at a rate of 10 g/day mixed with concentrate. Average daily weight gain tended to be greater in CEL than in CON, especially after 1 month of weaning. In Experiment 2 (16‐week duration), 10 calves (2.0‐month‐old females) were assigned to either a control group or an experimental group (KRA) fed kraft pulp at a rate of 10% replacement of total digestible nutrients with concentrate. The proportion of fibrolytic bacteria increased and that of methanogenic Archaea decreased in the rumen microbial community composition of KRA calves in Experiment 2, whereas the decrease in Fibrobacter and Archaea was observed in CEL calves at first 4 weeks in Experiment 1. We conclude that beta‐glucan prebiotic supplementation to grazing calves at pre‐weaning would affect rumen microbial composition and modified rumen fermentation characteristics, leading to a better rumen environment via different means.     

Beef heifer production as affected by indoor feed intensity and slaughter age when grazing semi-natural grasslands in summer

Only limited knowledge exists on how to produce high-quality beef carcasses when the cattle also are grazing semi-natural grasslands for nature conservation purposes. The objectives of the two factorially-designed trials were to determine the effects of indoor feed intensity (low vs. high) and slaughter age (18 vs. 22 months) on performance and carcass quality of beef heifers, raised from weaning until slaughter and grazing semi-natural grasslands during growing seasons. In the first trial, 56 Charolais heifers were used of which 28 were fed only grass-clover silage ad libitum (low; CL), and another 28 heifers were fed 2.0 kg of grain daily in addition to the silage (high; CH). In the second trial, 28 Angus heifers were fed grass-clover silage at 80% ad libitum (low; AL), whereas another 28 heifers were fed silage ad libitum (high; AH). According to a national nature conservation score, the grazing pressure on the semi-natural grassland was classified as having been satisfactory to maintain the floristic diversity as no litter had been accumulated onto the sward. From weaning until slaughter, no difference in average daily gains (ADG) was found between the CH and the CL, whereas the AH had higher ADG than the AL (693 vs. 573 g, P < 0.001). Heifers in both trials had higher carcass weights and more fat, Charolais heifers also had better conformation and Angus heifers had higher dressing percentage at 22 months than at 18 months of slaughter age (P < 0.05). In conclusion, carcass traits in both trials were more affected by slaughter age than by feed intensity and desirable grazing effects were achieved on the pasture.     

Efficiency of a pedometer device for detecting estrus in standing heat and silent heat in Japanese Black cattle

The usefulness of a radiotelemetric pedometer for estrus detection in standing (ST) heat, or in silent heat without ST events, but in which ovulation is observed, in Japanese Black cattle was investigated. The duration of an increase in steps in ST heat was 11.8 ± 1.3 hr, and it was similar to that of ST events (duration: 10.1 ± 0.8 hr). Even in silent heat, the change pattern and the duration (11.6 ± 0.2 hr) of the period with an increase in steps during estrus were not different compared with ST heat. When artificial insemination (AI) was performed at 15.5 ± 0.6 hr from the onset of estrus detected by the pedometer in ST heat cases, the conception rate was 57.1% (8/14). Furthermore, fertility in cattle that underwent silent heat was evaluated. When AI was performed at 14.4 ± 2.0 hr from the onset of estrus detected by the pedometer, the conception rate was 60% (3/5) in silent heat cases. The overall results suggest that the radiotelemetric pedometer is a valid device for detecting estrus and it can even detect silent heat in Japanese Black cattle. Moreover, even silent heat cattle are fertile when AI is performed at the appropriate time.     

Comprehensive evaluation of growth performance and meat characteristics of a fattening system combining grazing with feeding rice whole‐crop silage in Japanese Black steers

We investigated the effect of a system for fattening steers combining grazing with feeding rice whole‐crop silage (rWCS) on growth performance, meat characteristics, and the expression of genes involved in skeletal muscle growth. Steers were randomly assigned to grazing or concentrate‐fed groups (CT). The grazing group (GZ) was fed rWCS after grazing until 16 months of age. The final body weight was the same in the two groups, but the dressed weight was lower in the GZ than in the CT. The beef color standard was higher in the GZ than in the CT. Although beef marbling did not differ between the two groups, there was less intramuscular fat and subcutaneous fat in the GZ than in the CT. The α‐tocopherol and β‐carotene contents in the muscle were higher in the GZ than in the CT. The GZ showed a lower daily gain (DG) during the grazing period, which may have resulted from decelerating skeletal muscle growth caused by the increased expression of genes encoding myostatin and atrogin‐1. However, the DG and feed efficiency of the GZ increased after grazing. The two groups exhibited a similar level of beef productivity.     

Effect of feeding wood kraft pulp on the growth performance,feed digestibility,blood components,and rumen fermentation in Japanese Black fattening steers

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate‐to‐propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP.     

8个牛品种的大理石花纹评分相关基因变异的微卫星DNA池分析

本研究以8个牛品种为研究对象,利用与大理石花纹评分基因相关的7个微卫星位点结合DNA池分析技术,探讨微卫星DNA多态性与8个牛品种大理石花纹评分间的关系,并根据性状同质性原理预测品种组合,以加快生产出高端"雪花"牛肉。结果表明:日本和牛与荷斯坦牛、安格斯牛、渤海黑牛的相似性系数均超过0.8,而日本和牛与其他牛品种的的相似性系数均小于0.8。利用MEGA4软件采用邻接法进行聚类,利木赞牛与西门塔尔牛先聚合在一起,再与草原红牛聚合;渤海黑牛与鲁西黄牛2个地方良种聚合在一起,以上5个品种聚为第1大类。荷斯坦牛与日本和牛聚合,再与安格斯牛聚在一起,它们聚为第2大类。根据本研究结果和国外肉牛杂交生产实践,从牛肉大理石花纹性状的同质性出发,建议利用日本和牛、荷斯坦牛为亲本,杂交生产高档"雪花"牛肉,以解决我国的肉牛牛源短缺问题。     

Responsiveness of beef cattle (Bos taurus) to human approach,novelty, social isolation,restraint and trade‐offs between feeding and social companionship

This study investigated responsiveness of beef cattle to various environmental stimuli by subjecting 15–16 Japanese Black cows to five tests repeated twice. Within individual behavioral measures, cows were moderately (repeatability = 0.54–0.70) or highly (repeatability = 0.74–0.89) consistent in flight distance during grazing and resting in the human approach tests, maximum distance from the group pen and the number of total and different feed tub visits in the feeding–sociability trade‐off test, and unwillingness to enter the restraint, movement under restraint and flight speed after release from restraint in the social isolation and restraint test. By contrast, cows were not consistent in the latency to make the first contact and the number of contacts with novel object(s) in the novelty test (repeatability = 0.24–0.39). Across behavioral measures in different tests, cows showed no consistency (P ≥ 0.05) in any combinations of measures from the two human approach tests, the trade‐off test and the social isolation and restraint test. In conclusion, human approach (particularly during resting), feeding–sociability trade‐off and social isolation and restraint situations can be used for evaluating personality in Japanese Black cows, while the value of the novelty test needs to be reexamined.     

Effect of summer heat environment on body temperature,estrous cycles and blood antioxidant levels in Japanese Black cow

This study investigated the effect of summer heat environment on estrous cycles and blood antioxidant levels in Japanese Black cows. A total of 13 non‐lactating Japanese Black cows (summer: 9, winter: 4) were examined. Body temperature was measured rectally and intravaginally using a thermometer and data logger, respectively. Estrous behavior was monitored using a radiotelemetric pedometer that recorded walking activity. Rectal temperatures were higher during summer than winter (P < 0.001). There was an acute increase in vaginal temperature at the onset of estrus during winter but such an increase was not observed during summer. Walking activity during estrus decreased dramatically in the summer compared to the winter. Duration of estrous cycle was longer in summer (23.4 days, P < 0.05) than winter (21.5 days), and the subsequent rise in progesterone concentrations following estrus tended to be delayed in summer. The level of thiobarbituric acid reactive substances (TBARS) in peripheral blood cells was higher during summer (P < 0.05), while the levels of superoixde dismutase (SOD), glutathione peroxidase (GPx) and glutathione were lower (P < 0.05). These results indicate that high ambient temperature during summer increases both body temperature and oxidative stress, and also reduces signs of estrus in Japanese Black cows.     

Nutritional value of sugarcane silage enriched with corn grain,urea, and minerals as feed supplement on growth performance of beef steers grazing stargrass

The objectives were to evaluate the silage quality of sugarcane silage enriched (as fed) with corn grain ground (10%), urea (1.5%), and mineral premix (0.5%) and its effects as a feed supplement on growth performance of beef steers grazing stargrass. Firstly, in micro-silages, whole sugarcane enriched with corn grain, urea, and minerals (WSCE) were ensilaged by 0, 20, 40, and 60 days. Crude protein (CP) and lactic acid (LA) increased linearly (P < 0.05) and true protein decreased linearly (P < 0.05) as fermentation time increased. The pH values in silages were affected quadratically by fermentation time. Thus, after a 20-day fermentation, the pH values were below 4.5. Secondly, in micro-silos WSCE and stem sugarcane enriched with corn grain, urea, and minerals (SSCE) with and without calcium propionate were ensilaged by 30 days, but it did not affect any chemical composition trait in the silage. The SCCE silages had higher CP and LA and lower pH than WSCE silages. Finally, for 120 days, 20 beef steers (378 ± 33 kg initial BW) grazing stargrass were supplemented (daily by 1-h free access) with WSCE silage. Supplemental silage increased total dry matter intake, total gain, and the average daily gain, without any affectation on feed conversion and total tract digestion of dry matter. It is concluded that whole sugarcane silage is an alternative feed supplement to improve growth performance in beef steers grazing stargrass.