宁夏地区荷斯坦牛乳房性状的遗传参数估计和主成分分析

旨在评估宁夏地区荷斯坦牛乳房性状的遗传水平。本研究使用DMU（v6.0）软件的AI-REML模块结合EM算法并配合多性状动物模型对宁夏地区12 415头荷斯坦牛，包括111 735个观察值的9个乳房性状进行遗传参数估计，运用主成分分析法（PCA）探讨构象性状之间的关系。结果表明，宁夏地区荷斯坦牛乳房性状遗传力处于中等偏低水平，乳房深度遗传力值为0.242，乳房质地为0.080，悬韧带为0.183，前乳房附着为0.230，前乳头位置为0.231，前乳头长度为0.173，后乳房高为0.272，后乳房宽为0.378，后乳头位置为0.169。各性状遗传相关范围为-0.277~0.706，表型相关范围为-0.084~0.316。研究共筛选出特征值≥1的4个主成分，占总方差的64.19%，且9个乳房性状在前3个主成分中已全部体现，荷载系数均在0.4以上。本研究通过对宁夏地区奶牛DHI数据的深入挖掘和遗传参数估计，准确地把握了宁夏奶牛群体的结构特征，对于奶牛的选种选配和育种规划具有重要意义。     

荷斯坦奶牛隐性乳房炎与乳用特征的相关性分析

随机抽取荷斯坦奶牛 472头 (1～ 11胎 )进行奶牛隐性乳房炎的检测 ,乳用特征性状 (楞角性、尻宽、尻角度、后肢侧视、蹄角度 )的线性评定 ,以及隐性乳房炎与乳用特征的相关性分析。结果表明 :奶牛隐性乳房炎的乳区阳性率与楞角性、尻宽、尻角度、后肢侧视、蹄角度的相关系数分别为 0 1171、0 10 3 0、0 0 681、0 0 180、-0 12 65 ,其中与楞角性、尻宽分别达到显著水平 (P <0 0 5 )的正相关 ,与蹄角度达极显著 (P <0 0 1)的负相关。奶牛阳性率与楞角性、尻宽、尻角度、后肢侧视、蹄角度的相关系数分别为 0 0 967、0 0 5 61、0 0 2 82、0 0 12 7和 -0 0 670 ,其中除与楞角性为显著水平 (P <0 0 5 )的正相关 (0 0 967)外 ,其余均不显著 (P >0 0 5 )。     

中国荷斯坦牛干奶期长度的群体特征及其与生产性能的关系

本研究旨在探究北京地区中国荷斯坦牛干奶期长度（DPL）的变化规律及其变异对奶牛各项生产性能的影响，包括产奶性能、繁殖性能、初乳品质和乳房健康。收集了北京地区34个牧场出生于2009—2018年136 231头中国荷斯坦牛的干奶日期、生产性能记录、繁殖性能记录等。通过整理试验牛群的干奶记录，揭示了北京地区中国荷斯坦牛1胎和2胎DPL的群体规律，利用固定模型分析了胎次、产犊季节、场-产犊年和初产月龄对DPL的影响；此外，利用固定模型分析了DPL的变异对日产奶量、乳脂率、乳蛋白率、首末次配种间隔（interval from first to last insemination，IFL）、产犊至首次配种间隔（interval from calving to first insemination，ICF）和初乳品质的影响，利用Logistic回归过程分析了DPL的变异对首次配种受胎率（conception rate of first insemination，CR）、首次配种56 d不返情率（56-days non-return rate of first insemination，NRR56）、难产率和乳房健康的影响。研究结果显示，北京地区中国荷斯坦牛DPL平均为58.81 d，胎次、产犊季节、场-产犊年和初产月龄均对DPL有显著影响（P<0.05）。DPL的变异对日产奶量、乳蛋白率、ICF、CR、NRR56、难产率和乳房健康有显著影响（P<0.05）。干奶期短的奶牛测定日平均乳蛋白率、CR和NRR56更高；DPL适中的奶牛测定日平均产奶量更高、乳房健康水平更好、ICF更短、难产率更低。本研究在国内利用大规模牛群数据揭示了中国荷斯坦牛DPL的群体规律，可为中国规模化奶牛场提升管理水平提供参考。     

Diagnosis and treatment of mastitis in mares

Infection and inflammation of the udder (mastitis) is a common condition affecting all domestic mammals, but it appears to be less prevalent in mares than in dairy cows and dairy goats. The seemingly reduced incidence of mastitis in mares can be partially explained by the smaller size and relatively concealed location of the mare’s udder, coupled with a smaller storage capacity than cows and goats. Mastitis can affect lactating, peripartum, dry mares, mares at dry-off or prepubertal foals. Common clinical signs include swollen mammary tissue, abnormal mammary gland secretion, fever and anorexia; less common signs are hindlimb lameness and a swollen mammary vein. On rare occasions, mastitis pathogens can severely affect the nursing foal and mares may develop fibrotic tissue and consequent agalactia in the side(s) or quarter(s) affected. Based on the clinical presentation, mastitis can be classified as acute or chronic, and clinical or subclinical. Diagnosis is based on the clinical signs aided with aerobic culture and cytological evaluation of the gland secretion. In addition, these ancillary tests can also be used to assess prognosis and duration of treatment. Mares suffering from mastitis may present neutrophilia and hyperfibrinogenaemia. Treatment for mastitis includes antimicrobial therapy (systemic and/or locally), nonsteroidal anti-inflammatory drugs, frequent milking and cold hosing with/without hot-packing applied on the gland. While the frequent monitoring of mares after weaning and reducing food intake should be part of common practices at weaning, cleaning of the udder, control of insect populations and frequent milking of mares with a foal unable to nurse can also aid in preventing mastitis.     

The contribution of mammary infections by coagulase-negative staphylococci to the herd bulk milk somatic cell count

Quarter foremilk samples were taken at 2–3 weekly intervals for several years in a experimental herd comprising about 45 cows. The samples were submitted to bacteriological analysis and somatic cell counting. The most prevalent quarter infections from 1982 to 1988 were by coagulase-negative staphylococci (15–20% of all the quarters sampled). Most of these (75.6%) persisted until drying-off Dry cow therapy eliminated 86.5% of these infections. Comparison of udder quarters within cows, involving 775 samples from pairs of non-infected quarters and quarters infected by coagulase-negative staphylococci, yielded geometric means of somatic cell counts of 210 000 and 420 000 cells/ml, respectively. The correlation (r=0.87) between the herd bulk milk somatic cell count (SCC) and its estimation from the quarter milk somatic cell count performed on the same day allowed us to evaluate the contribution of the different categories of quarters, according to their infection status, to the herd bulk milk SCC. Quarters infected by a major pathogen (8.5% of samples) gave rise to 46.6% of the total number of cells, while quarters infected by coagulase-negative staphylococci (17.8% of samples) gave rise to 18.1%. Although coagulase-negative staphylococci represented only a secondary source of somatic cells as compared to major pathogens, they were not a negligible source considering the threshold of 300 000 somatic cells advocated for herd milk of good quality.     

The detection of subclinical mastitis in the bactrian camel (Camelus bactrianus) by somatic cell count and California mastitis test

Milk samples (n=160) from 7 clinically healthy bactrian camels were cultured to detect subclinical udder infection. The samples were assessed by the Californian mastitis test (CMT) and somatic cell count (SCC). Bacteria were recovered from 36 (22.5%) of the milk samples. Staphylococcus aureus and coagulase-negative staphylococci (CNS) were the main organisms found.Infected quarters had significantly higher mean values for the SCC (p<0.01) and CMT (p<0.001) than non-infected quarters. All 7 camels were infected with CNS but only 4 with S. aureus. CMT values for S. aureus-infected camels were significantly higher than for those only infected with CNS. The values for SCC and CMT were significantly influenced by the stage of lactation (p<0.05). No significant difference was found from the effect of the quarters. Both SCC and CMT were of value in predicting the infection status of the udder.Abbreviations CMT California mastitis test - SCC somatic cell count - CNS coagulase-negative staphylococci     

A Field Study on Group Housing of Lactating Sows with Special Reference to Sow Health at Weaning

Four farms that group-housed sows from 2 weeks of lactation until weaning (G-farms) and 3 farms that kept the sows individually penned throughout the 5 to 6-week-long lactation period (C-farms), were compared in terms of sow health. All sows were crossbred Swedish Yorkshire × Swedish Landrace. The daily food ration was similar on all farms except during the group-housing period, when G-farm sows were fed ad libitum. Sows were grouped in the breeding section and kept grouped on deep litter in the dry sow section on all farms. Individual health examinations were performed at the time of weaning (±4 days) on 179 G-farm sows and on 167 C-farm sows. Teat- and udder skin wounds occurred less frequently (p<0.001) in G-farm sows than in C-farm sows. In addition, preweaning atrophy of all mammary glands occurred in 6.6% of the G-farm-sows but not in a single C-farm sow (p<0.001). This indicates that sow-piglet interactions decrease when sows are group housed. However, these differences did not occur in primiparous sows, suggesting that the relation between the primiparous sow and her litter is not affected. Mastitis frequency was the same in the 2 systems. Moreover, the frequency of locomotor disorders was the same in the 2 groups, and hoof overgrowth was common in both systems. These similarities could be due to the fact that all farms group housed dry sows on deep litter. A strong relation (p<0.001) between hoof overgrowth and locomotor disorders was evident. Low access to food due to low rank among primiparous group-housed sows was indicated by a lower (p<0.05) backfat thickness compared with multiparous sows, and a higher (p<0.001) frequency of skin wounds compared with individually housed primiparous sows.     

Equine mammary gland disease with a focus on botryomycosis: A review and case study

Mammary gland problems occur incidentally in horses and one of the rarer conditions is botryomycosis (bacterial pseudomycosis, bacterial granuloma, staphylococcal pseudomycetoma). This article includes a short review of equine mammary gland problems inappropriate lactation, mastitis and neoplasia and botryomycosis, and additionally 2 clinical cases of botryomycosis of the udder resulting from Staphyloccocus aureus infection will be discussed. Both cases involved nonpregnant, nonlactating mares referred for chronic mammary inflammation with draining abcessation. In both mares, botryomycosis caused by S. aureus was confirmed by histopathology and a bacterial culture. Both mares recovered fully after surgical hemimastectomy under general anaesthesia.     

地中海奶水牛乳房形态结构与泌乳性能的关联分析

本研究通过分析不同胎次乳房性状之间的相关性以及乳房性状与泌乳性能之间的相关性,建立地中海奶水牛乳房线性性状的入选主成分评估模型,为培育具有优良乳房性状的高产奶水牛提供参考。收集意大利牧场123头地中海水牛共1 107条生产记录信息,利用SAS 9.2 CORR过程进行相关性分析,运用PRINCOMP过程建立入选主成分评估模型。结果表明,1~4胎时,270 d泌乳量随着胎次的增加而增加;在1~2胎时,前乳头长与后乳头长呈极显著正相关（P<0.01）;3胎及3胎以上时,前乳头长与后乳头长呈显著正相关（P<0.05）;1~4胎时,乳区面积与前乳头距、前后乳头距、后乳头距呈极显著正相关（P<0.01）,且前乳头距与后乳头距呈极显著正相关（P<0.01）;在≥ 4胎时,前后乳头距与泌乳量、乳蛋白量呈显著正相关（P<0.05）,并与乳脂量呈极显著正相关（P<0.01）,同时乳区面积与泌乳性能呈显著正相关（P<0.05）;在第1~2、4胎及以上时,泌乳量、乳蛋白量和乳脂量之间呈极显著正相关（P<0.01）,且在第3胎时泌乳性能之间呈显著正相关（P<0.05）。入选主成分评估模型为：Y=0.2631x1+0.1186x2+0.0862x3+0.0796x4+0.1039x5+0.0042x6-6.9689,式中,x1,前乳头长;x2,后乳头长;x3,前乳头距;x4,前后乳头距;x5,后乳头距;x6,乳区面积。本研究进一步阐明了地中海奶水牛不同胎次乳房性状之间存在相关性,而乳房性状与泌乳性能之间的相关性受胎次的影响。     

Prenatal Diagnosis of Megacystitis and Hydronephrosis in an Equine Fetus: How Transabdominal Ultrasonography Can Help to Diagnose Fetal Abnormalities

Premature udder development constitutes an alarm signal in pregnant mares. The objective of this clinical case report is to highlight the importance of transabdominal ultrasound examination of the fetus in these cases and to report a unique case of prenatal diagnosis of obstructive uropathy based on the observation of severe fetal hydronephrosis and megacystitis in utero. A 4-year-old French chaser primiparous mare was referred for evaluation of premature udder development during the ninth month of pregnancy. The mare had clinical signs within normal limits, a developed and sensitive udder with secretions, and no vulvar discharge. Transrectal examination revealed the presence of an immobile fetus. Combined uteroplacental thickness was within normal limits. Transabdominal ultrasound revealed a single live fetus in posterior presentation with several abdominal abnormalities. Unilateral hydronephrosis and megacystitis lead to a hypothetical diagnosis of fetal multiple urinary tract malformation with outflow obstruction. Treatment was discontinued and the mare was monitored. Abortion occurred spontaneously a week later. Postmortem examination revealed a ruptured bladder of abnormally large dimensions and a severely distended left kidney without parenchyma (filled with free urine) and lack of permeability in the left ureter and urethra. Postmortem diagnosis was consistent with our prenatal ultrasonographic diagnosis. Even though described during human pregnancy with various etiologies and severity, prenatal diagnosis of fetal hydronephrosis and megacystitis has not been reported in equine veterinary medicine before. These malformations need to be characterized more precisely in the future. This case highlights the importance of transabdominal ultrasonography to detect equine fetal abnormalities.