Japanese Black Calves Research Articles

鹿児島県産黒毛和種における損徴発生状況に関する調査研究

鹿児島県産黒毛和種における損徴発生状況に関する調査研究

“From today’s medical card” A case of severe wheezing caused by trachea stricture due to a costal bone fracture in Japanese black calf

“From today’s medical card” A case of severe wheezing caused by trachea stricture due to a costal bone fracture in Japanese black calf

Effects of temperature-humidity index on health and growth performance in Japanese black calves.

We evaluated the relationship between the temperature-humidity index (THI) and health and growth performance in Japanese black calves in Japan. Data were collected from medical records of 19,313 Japanese black calves aged up to 3months for correlation analysis with THI from July 2008 to June 2011. Data were also collected on the market weights of 57,144 Japanese black calves, and we calculated the body weight gain (BWG) of each calf based on body weight and age in days at the calf market. Analysis for the relationship between disease incidence and THI demonstrated a negative correlation (r = -0.54, p < 0.01). In addition, the mean disease incidence at THI of ≤50 was significantly higher than that at THI of ≥71. Analysis for the relationship between growth performance in calves and THI revealed that a lower THI during the month of birth was associated with a lower BWG at the calf market and that BWG with THI of ≤70 was significantly lower than that with THI of ≥71 (p < 0.05). In contrast, a higher mean THI during the third month after birth was associated with a lower BWG at the calf market, and BWG with THI of >75 was significantly lower than that with THI of ≤50 or THI ranging from 56 to 60 (p < 0.05). These results indicate that Japanese black calves are susceptible to a cold environment immediately after birth, whereas they are susceptible to a heat environment 3months after birth.

悪性黒色腫と診断された黒毛和種育成牛の2症例

悪性黒色腫と診断された黒毛和種育成牛の2症例

黒毛和種子牛の呼吸器病における血清亜鉛濃度

黒毛和種子牛の呼吸器病における血清亜鉛濃度

黒毛和種子牛への甘草給与が血中GH および IGF-1 濃度に与える影響

黒毛和種子牛への甘草給与が血中GH および IGF-1 濃度に与える影響

Higher Intake of Milk-Replacer Pre-Weaning Enhances Post-Weaning Insulin-Like Growth Factor 1 Levels in Japanese Black Cattle

Alterations in early pre-natal nutrition of Japanese Black calves influence the glucose and lipid metabolism after weaning. However, the effects of early nutritional status on the endocrine system in later life stages in Japanese Black cattle are unknown. This study examined how post-weaning plasma levels of growth hormone (GH), insulin-like growth factor 1 (IGF-1), and blood insulin, which are hormones affecting growth and meat quality, and metabolites were affected by feeding 1800 g versus 500 g of milk replacer to Japanese Black cattle (5 per group) during nursing. Up to weaning (90 days post-birth), all calves received calf starter and hay ad libitum, and post-weaning, they received a concentrate feed and hay ad libitum. Plasma concentrations of GH and IGF-1 were greater at weaning in the high-milk-replacer group (P<0.1 and P<0.01, respectively), and elevated IGF-1 concentrations persisted until the study end (210 d) (P<0.05), suggesting that the levels were sustained independent of the influences of both GH and nutrient intake. Blood insulin and metabolites (plasma glucose, beta-hydroxybutyric acid, and non-esterified fatty acids) were not significantly different between the two groups. The results of this study suggest that feeding calves a high volume of milk replacer during nursing will increase IGF-1 secretion well beyond weaning.

口蹄疫を疑う通報を受けた農場での多様な病変を呈した牛丘疹性口炎の発生と拡大

口蹄疫を疑う通報を受けた農場での多様な病変を呈した牛丘疹性口炎の発生と拡大

Blood biochemical values in Japanese Black calves in Kagoshima Prefecture, Japan.

To obtain blood biochemical basic data of Japanese Black calves in Kagoshima Prefecture, Japan, blood samples were obtained from 582 clinically healthy calves on 27 farms. Calves were divided into three stages: the suckling stage (between 14 and 90 days of age, n=191), the early growing stage (between 91 and 180 days of age, n=200) and the late growing stage (between 181 and 270 days of age, n=191). The mean concentration of total cholesterol, triglyceride, nonesterified fatty acids, calcium and zinc, and the mean activities of γ-glutamyltransferase and alkaine phospatase in the suckling stage were significantly higher than those in the early and late growing stages (P<0.01). The mean concentration of total protein, albumin and globulin increased gradually with growing. The mean concentration of beta-hydroxybutyrate in the suckling stage was below 150 µmol/l, however, it elevated above 400 µmol/l in the early and late growing stages. The mean concentration of copper concentration was above 70 µg/dl in all stages. The mean concentration of zinc was between 90 and 110 µg/dl in all stages. These results suggest that the blood biochemical values of Japanese Black calves vary with growing stages, and the blood parameters obtained in this study are considered useful as indices for health management of Japanese Black calves.

Effect of Suckling Systems on Serum Oxytocin and Cortisol Concentrations and Behavior to a Novel Object in Beef Calves.

We investigated differences between effects of natural- and bucket-suckling methods on basal serum oxytocin (OT) and cortisol concentrations, and the effect of OT concentration on affiliative and investigative behavior of calves to a novel object. Ten Japanese Black calves, balanced with birth order, were allocated evenly to natural-suckling (NS) and bucket suckling (BS) groups. Blood samples were collected at the ages of 1 and 2 months (1 week after weaning) calves, and serum OT and cortisol concentrations were measured using enzyme-linked immunosorbent assay and enzymeimmunoassay tests, respectively. Each calf at the age of 2 months (2 weeks after weaning) was released into an open-field with a calf decoy, and its investigative and affiliative behaviors were recorded for 20 minutes. In 1-month-old calves, the basal serum OT concentration (25.5±4.9 [mean±standard deviation, pg/mL]) of NS was significantly higher than that of BS (16.9±6.7) (p<0.05), whereas the basal cortisol concentration (5.8±2.5 [mean±standard deviation, ng/mL]) of NS was significantly lower than that in BS (10.0±2.8) (p<0.05). Additionally, a negative correlation was noted between serum OT and cortisol concentrations in 1-month-old calves (p = 0.06). Further, the higher serum OT concentration the calves had at 1 month old, the more investigative the calves were at 2 months old but not affiliative in the open-field with a calf decoy. Thus, we concluded that the natural suckling method from a dam elevates the basal serum OT concentration in calves, and high serum OT concentrations induce investigative behavior and attenuate cortisol concentrations.

Effects of supplementation with cellooligosaccharides on growth performance of weaned calves on pasture.

We conducted two feeding experiments to evaluate the effects of cellooligosaccharide (CE) supplementation on growth performance in grazing beef calves. Calf sex and age and duration of the experimental period differed between the experiments. Experiment 1 (10 weeks) used 5.6-month-old castrated males; Experiment 2 (13 weeks) used 3.9-month-old females. Eight Japanese Black calves were assigned to either a control group (CON) or an experimental group (CE) fed CE at a rate of 10 g/day mixed with concentrate. Calves were stocked in fields in which Kentucky bluegrass was dominant. In both experiments, average daily gain tended to be greater in CE than in CON, especially in late stages of experiments, but no significant differences in body weight changes were observed. In Experiment 2, final heart girth was larger in CE than in CON calves. We monitored rumen microbial community composition in Experiment 2 and found increases in fibrolytic bacteria and methanogenic archaea in CE calves, but the overall microbial composition did not differ between the groups. Our results suggest that supplementation with CE may positively affect growth performance in weaned calves on pasture, but longer-term CE supplementation may be required to exhibit the effect.

Effect of supplemental vitamin E on the peripheral blood leukocyte population in Japanese Black calves.

We investigated the effect of supplemental vitamin E on the peripheral blood leukocyte population in Japanese Black calves. Twenty-six calves kept at the same farm were studied. They were divided into two groups; thirteen calves received 300 IU/day of vitamin E orally from 1 to 3 months of age (VE group), and the other thirteen calves did not receive the vitamin E supplement (control group). The VE group showed a higher serum vitamin E concentration at 2 and 3 months of age compared with the control group (P<0.01). The numbers of CD3+ cells and CD4+ cells were higher in the VE group than in the control group, and the difference was statistically significant at 3 months of age (P<0.05). The numbers of CD21+ cells were higher in the VE group than in the control group, and the difference was statistically significant at 2 months of age (P<0.05). The numbers of CD335+ cells tended to be higher in the VE group than in the control group. The numbers of CD8+ cells and CD14+ cells tended to be higher in the VE group than in the control group at 3 and 4 months of age. This study demonstrated that the supplementation of suckling Japanese Black calves with vitamin E might affect the numbers of some immune cell types in the peripheral blood.

Molecular characterization of Cryptosporidium andersoni isolated from Japanese black calves in Tokachi district, Hokkaido Prefecture, Japan

Molecular characterization of <i>Cryptosporidium andersoni</i> isolated from Japanese black calves in Tokachi district, Hokkaido Prefecture, Japan

大分県における黒毛和種育成子牛の牛毛包虫症の発生状況とその対策

近年大分県では，子牛市場への出荷前の育成子牛において，育成子牛価格に悪影響を及ぼす皮膚病が散見されることから，その発生状況と対策について調査した．2011年８月から2014年６月にかけて大分県のS地区とY地区において，240 ～ 269日齢（254.32±8.52，平均±標準偏差）の黒毛和種肥育素牛2,106頭を対象に，家畜市場出荷前のワクチン接種時に視診及び触診検査を行うとともに，牛毛包虫（Demodex bovis）感染が疑われた131頭について寄生虫学的検査を実施した．また，予防および治療についても検討を行った．その結果，虫体の大きさ（体長×体幅）は，毛包内の雌成ダニ（n=28）では平均で232.7×66.71μm，雄成ダニ（n=24）では264.51×67.68μmであり，痂疲内の雌成ダニ（n=30）では218.8×63.47μm，雄成ダニ（n=19）では219.0×57.51μmであった．また，皮膚表面の雌成ダニ（n=2）では135.8×53.89μmであった．結節は頚部が67%（67/100）で最も多くみられた．また，雌雄間で発症に差はなく，発生は４カ月齢よりみられ，７カ月を過ぎると急速に増加した．母子接触により次の産次の子牛にも結節症状がみられた母牛の割合は，49%（30/61）であった．各農場における対策内容を調査した結果，予防にはイベルメクチンポアオン製剤の投与が，治療にはフルメトリンポアオン製剤の１週間ごと２回投与が有効であることが分かった．毛包虫症は年々増加傾向にあり，気温の高い時期に発生が増加する傾向にあるが，吸血昆虫による刺傷痕が多くみられる６月から８月は本症の結節との鑑別が必要である．また，毛包虫症の皮膚病変は多岐にわたり，二次感染などにより複雑化した難治性皮膚病では積極的な検査が必要と考えられた．

遺伝子型をデザインした黒毛和種の効率的作出の試み

本研究では，枝肉重量および脂肪交雑において高い育種価を持つ長期不受胎の雌牛の卵子を用いて，求める遺伝子型を持つ子牛を効率的に生産することおよび高い育種価を持つ雌牛の卵子の有効利用を 目的とした．成長ホルモン（Growth hormone : GH）遺伝子，脂肪酸不飽和化酵素（Stearoyl-CoA desaturase : SCD）遺伝子の遺伝子型について，栃木県畜産酪農研究センターの高い経済形質を持つ雌牛4頭および黒毛和種雄牛8頭（凍結精液）を解析した．これらの結果をもとに，増体が良く，融点が低い脂肪で構成される肉を持つウシとなるよう卵子と精子の遺伝子型の組み合わせを考慮した．雌牛4頭が屠場に出された際に得られた卵巣から卵子を採取し，体外で成熟-受精-培養させて遺伝子型をデザインした胚盤胞を作出した．作出された8個の胚盤胞を4頭の雌牛に移植したところ2頭受胎し，雄1頭が誕生した．この子牛を育成および肥育したところ，増体において全国平均より高い成績を示した．

Membranoproliferative Glomerulonephritis in a Calf with Nephrotic Syndrome

A 2-month-old Japanese black calf was presented with a history of weight loss, exophthalmos and subcutaneous oedema of the brisket. Urinalysis and serum biochemistry showed proteinuria and hypoproteinaemia suggestive of nephrotic syndrome. Microscopically, lesions in the kidney were characterized by proliferation of mesangial cells and diffuse thickening of the glomerular basement membranes with the appearance of double contours. Immune complex deposits were confirmed by electron microscopy and immunofluorescence using reagents specific for bovine immunoglobulin G, complement factor C3 and bovine viral diarrhoea virus (BVDV). Consequently, the glomerular lesion in this case was diagnosed as membranoproliferative glomerulonephritis. BVDV type 1 was detected in serum by nested reverse transcriptase polymerase chain reaction. Viral antigen was also identified in the glomeruli by immunofluorescence. These results suggest that BVDV may have been the cause of immune complex glomerulonephritis in this calf.

Comparison of cytokine mRNA expression in peripheral CD4+, CD8+ and γδ T cells between healthy Holstein and Japanese Black calves

Japanese Black (JB) calves are more susceptible to infectious diseases compared to Holstein (Hol) calves. To clarify the immunological differences between JB and Hol calves, expression of cytokine messenger RNA (mRNA) was examined using peripheral CD4(+) , CD8(+) and γδ T cells. Healthy calves, 24 from each species, were examined. Blood samples were obtained from calves at 1 week, 1 month and 3 months old, eight calves for each age of each species. Peripheral blood mononuclear cells were stimulated with phytohemagglutin (PHA), and T cell subsets were isolated by positive selection using magnetic cell sorting (MACS). Levels of interlekin (IL)-2, IL-4, IL-10 and interferon (IFN)-γ mRNA in three T cell subsets were analyzed. WC1-N1(+) γδ T cell percentages were significantly lower in JB calves at 1 week and 1 month of age compared to Hol calves. In addition JB calves had significantly lower IL-2, IL-10 and IFN-γ mRNA in WC1-N1(+) γδ T cells at 1 and 3 months of age, whereas there were no significant differences in cytokine mRNA of CD4(+) and CD8(+) cells between the two groups. Decreased cytokine mRNA and cell number of peripheral γδ T cells may affect negatively on the immune system of JB calves.

IARS異常症における臨床症状および血液性状の特徴

IARS異常症における臨床症状および血液性状の特徴

Diurnal Variation of Plasma Bone Markers in Japanese Black Calves

ABSTRACTTo evaluate diurnal variation of plasma bone markers, blood samples were collected from five calves at 2-hr intervals throughout a 24-hr period. Tartrate-resistant acid phosphatase isoform 5b (TRAP5b), carboxy-terminal collagen crosslinks of type-I collagen (CTX), hydroxyproline, bone specific alkaline phosphatase (BALP) and osteocalcin were measured. Cosinor analysis showed a significant rhythm in all bone markers. The acrophase of each bone marker appeared from the early to late morning. The percentage ratio of the amplitude to mesor and the within-subject variability for CTx and osteocalcin were significantly larger than those for TRAP5b and BALP. This marked diurnal variation in five bone markers suggested that the time of blood sampling should be fixed when studying bone marker concentrations in bovine plasma.

WCSを起こす原因遺伝子の探求－ IARS異常症の発見と今後の展望

WCSを起こす原因遺伝子の探求－ IARS異常症の発見と今後の展望