A case-control study to identify farm factors affecting fertility of dairy herds: univariate description of factors

Objective To identify farm factors which were associated with reproductive performance in dairy herds in New South Wales.
Procedure A survey was administered by face to face interview to examine the responses of producers drawn from 757 herds, which used the New South Wales Agriculture Department Dairy Herd Improvement scheme. A case-control approach was used to select a total of 126 herds from the first (top group - cases) and fourth quartiles (low group - controls) for intercalving interval.
Results We found that the estimated interval from calving to first mating was significantly different between groups (P = 0.03) and that the groups significantly differed in both their target for interval to first mating (P = 0.02) and their perceived optimum time for first mating (P = 0.04). Other factors associated with a longer intercalving interval included, use of embryo transfer programs (P = 0.08), younger managers (P = 0.02), fewer breedings per day (P = 0.01), a greater number of people detecting heats (P = 0.07), but less hours spent detecting heats while handling the cows (P = 0.11), and a failure to vaccinate bulls for campylobacteriosis (P = 0.14).
Conclusions Managers of herds with poorer reproductive performance did not intend to mate cattle as soon after calving as managers with better reproductive performance, were not as active in seeking veterinary advice on reproduction, and were attempting to treat reproductive diseases and disorders themselves.     

Effect of suckling intensity on human growth hormone binding, biochemical composition and histological characteristics of ovine mammary glands

Suckling both, or only one contralateral mammary gland during 15 days postpartum was utilized to study lactogenic hormone binding to mammary microsomal membranes and quantitative mammary morphology in ewes. Binding of radiolabeled human growth hormone was specific for lactogenic hormones. Non-radiolabeled human growth hormone, ovine and bovine prolactin and human placental lactogen effectively competed with radiolabeled human growth hormone for binding sites but ovine and bovine growth hormone were completely ineffective. Specific binding of radiolabeled human growth hormone to 600 μg of membrane protein averaged 23 ± 3% in all lactating glands. Neither days postpartum nor treatment of contralateral mammary glands substantially altered hormone binding in lactating glands. Specific human growth hormone binding (6 ± 0.5%) in non-suckled glands (15 days postpartum both udder halves) was significantly lower (P<0.01) than in lactating tissue but only a moderate and variable reduction in specific binding was measured in membranes from glands non-suckled for 15 days but contralateral to a suckled gland (14 ± 4%). Specific binding was approximately doubled in assays with 600 compared with 300 μg of membrane protein and the pattern of binding among variously suckled glands was not changed by treatment of membranes with 4 M MgCl₂ prior to assay. Most secretory cells from all lactating glands had rounded, basally displaced nuclei, apical fat globules, secretory vesicles and abundant densely stained basal cytoplasm (ergastoplasm). Alveolar lumenal area was maximal (50% of tissue area) and stromal tissue area was minimal. After 15 days of non-suckling (both udder halves) mammary cells were engorged with lipid, ergastoplasm was reduced and nuclei were irregularly shaped and randomly displaced compared with lactating tissue. In addition, lumenal area was reduced and stromal tissue more evident. Lack of suckling for 5 days had little apparent effect on mammary cytology. Like lactogenic hormone binding, mammary tissue morphology was only moderately altered by 15 days of non-suckling when the remaining gland was suckled. RNA concentration was lowest (2.1 ± 0.3 mg/g) in mammary tissue from ewes in which neither gland was suckled for 15 days postpartum but non-suckling interval had no significant effect when contralateral glands were suckled. DNA concentration was not significantly influenced by suckling treatments. Relative lactogenic hormone binding closely corresponded to changes in cytological and biochemical indices of secretory cell function.     

Growth-related changes in the pulmonary function of goats

Growth-related changes in pulmonary function values were investigated in 20 healthy French Alpine goats, aged between 20 and 550 days, weighing 7–55 kg. Pulmonary ventilation, mechanics of breathing and arterial oxyten tension were measured using standardized techniques and methods adapted for goats of different body sizes. The Ppl values and the tI/tTOT ratio showed no significant changes with age and body size. The ventilation values (Vt, Ve, mVI and mVE) increased linearly with growth. There was a significant correlation of age and body weight with dynamic lung compliance (Cdyn), total pulmonary resistance (RL), viscous work of breathing (Wvis tot) and minute viscous work (Wvis min) throughout the age range studied. Cdyn, Wvis tot and Wvis min increased and RL decreased with age and body weight. Arterial blood gases (PaO₂ and PaCO₂) did not show significant changes over the age range studied. Regression equations for each pulmonary function parameter are given with body weight as the independent variable. Data for the mechanics of breathing were compared with those elsewhere for cattle, horses, man and dogs.     

氯化钠对饲喂棉饼诱发山羊泌尿系结石的预防试验

16只3~5月龄阉割波尔公山羊随机分为4组,即对照Ⅰ组(n=3)、对照Ⅱ组(限水对照组n=3)、试验Ⅰ组(n=5)、试验Ⅱ组(限水试验组,n=5)。对照组饲喂羊精料和花生秧,试验组饲喂棉饼和稻草,同时在试验组棉饼中加入4%棉饼量的氯化钠,对照Ⅰ组和试验Ⅰ组在试验期间不限制饮水,而对照Ⅱ组和试验Ⅱ组每天限制饮水,经预试期后试验期为4个月。结果表明:(1)添加氯化钠各试验组均未发现临床型尿石症,未添加氯化钠对照Ⅰ组有1头发病,未添加氯化钠限水对照Ⅱ组有3头发病。(2)添加氯化钠不限制水组,山羊的饮水量、排尿量较未添加氯化钠组(对照组)明显增加,尿液pH值明显降低,且差异显著;而添加氯化钠限水组,山羊的排尿量、尿液pH值与限水对照组差异不显著。(3)两个试验组血清醛固酮含量较对照组明显降低,并且尿沉渣生成量明显减少。由此推测氯化钠预防棉饼诱发山羊泌尿系结石的机理是通过降低血清中的醛固酮含量,减轻醛固酮对肾脏的损害,减少了结石核心的形成和尿液中盐类结晶沉着点,在非限饮水的情况下羊还可通过增加饮水量和排尿量,使沉渣生成量减少,从而有效地防止尿石症的发生。     

努比亚山羊LMCD1基因生物信息学分析、真核表达载体的构建及表达

【目的】 扩增努比亚山羊LIM结构域基因1（LIM domain gene 1,LMCD1）并进行生物信息学分析,构建真核表达载体并检测LMCD1基因的表达情况,为研究努比亚山羊LMCD1基因功能及探究LMCD1基因在山羊骨骼肌肉发育中的作用提供依据。【方法】 从努比亚山羊背最长肌组织中提取总RNA,应用RT-PCR方法扩增LMCD1基因CDS区序列,并进行生物信息学分析;将LMCD1基因以同源重组的方式连接pEGFP-N1载体,经酶切、测序鉴定后重组阳性质粒命名为pEGFP-N1-LMCD1;将pEGFP-N1-LMCD1重组质粒转染至山羊骨骼肌卫星细胞,通过实时荧光定量PCR检测努比亚山羊LMCD1基因的表达情况。【结果】 努比亚山羊LMCD1基因CDS区序列全长1 092 bp,编码363个氨基酸。LMCD1蛋白分子式为C₁₇₇₅H₂₈₁₈N₅₀₈O₅₃₃S₂₉,分子质量为40.73 ku。努比亚山羊LMCD1基因CDS区序列与山羊相似性最高（99.8%）,与斑马鱼相似性最低（55.4%）,与其他物种的相似性在87.0%~98.8%之间。LMCD1蛋白无信号肽,不存在跨膜结构域,为亲水性蛋白。通过构建努比亚山羊pEGFP-N1-LMCD1真核表达载体并转染至骨骼肌卫星细胞,过表达LMCD1基因,产生绿色荧光信号。【结论】 试验成功扩增LMCD1基因CDS区序列,构建了pEGFP-N1-LMCD1真核表达载体,并分析了生物学功能,为后续开展LMCD1基因在山羊骨骼肌肉发育中的机制研究提供了理论基础。     

关中奶山羊睾丸不同发育阶段代谢物的差异分析

【目的】 试验旨在从代谢组学角度探究关中奶山羊睾丸发育代谢机制。【方法】 选择1月龄断奶雄性关中奶山羊和24月龄体成熟的雄性关中奶山羊各6只,采集睾丸组织,使用液相色谱-质谱（LC-MS）技术对睾丸组织进行化学检测,通过多维和单维分析相结合的方式对两组不同代谢物进行化学检测、对比与鉴别,通过富集差异代谢物分析筛选关中奶山羊发育代谢中的潜在关键通路。【结果】 在1和24月龄关中奶山羊睾丸组织中共筛选出334个差异代谢物,其中显著上调137个,显著下调197个。对前36个差异代谢物进行比较鉴定发现,分别为脂质和类脂质分子、有机酸及其衍生物、未分类化合物和苯丙烷和聚酮化合物四大类。经相关性分析发现,在1和24月龄关中奶山羊睾丸发育过程中,脂质和类脂质分子与甘油磷脂呈最大正相关,羧基及其衍生物与甘油磷脂呈最大负相关。对不同的代谢物进行富集分析,筛选出7条潜在的重要代谢通路,分别为肿瘤中的胆碱代谢、精氨酸和脯氨酸代谢、肿瘤中的中心碳代谢、铁死亡、谷胱甘肽代谢、氨酰-tRNA生物组成以及牛磺酸和亚牛磺酸代谢。【结论】 本试验从代谢组学角度揭示了1和24月龄关中奶山羊睾丸的差异代谢物及代谢机制,为今后哺乳动物睾丸的发育研究奠定了基础。     

The effect of feeding maize husk and leucaena mixed or separately on the voluntary intake of the husk

The effect of feeding maize (Zea mays L.) husk and leucaena (Leucaena leucocephala) as a mixture or separately on the voluntary intake of maize husk was studied over a 40-day period. Ten male goats with an average weight of 15 kg were used. The maize husk intake and total dry matter intake for the two feeding methods was about the same. Thus, total dry matter intake was not affected (P<0.05) by the feeding method. There was also no significant difference (P<0.05) between the two feeding methods in the digestibility values. The data were considered to indicate that there were no significant differences in the intake of maize husk when fed in a mixture with leucaena or when offered separately but at the same time.     

The effects of farm management practices on liver fluke prevalence and the current internal parasite control measures employed on Irish dairy farms

Fasciolosis caused by Fasciola hepatica is responsible for major production losses in cattle farms. The objectives of this study were to assess the effect of farm management practices on liver fluke prevalence on Irish dairy farms and to document the current control measures against parasitic diseases. In total, 369 dairy farms throughout Ireland were sampled from October to December 2013, each providing a single bulk tank milk (BTM) sample for liver fluke antibody-detection ELISA testing and completing a questionnaire on their farm management. The analysis of samples showed that cows on 78% (n = 288) of dairy farms had been exposed to liver fluke. There was a difference (P < 0.05) between farms where cows were positive or negative for liver fluke antibodies in (a) the total number of adult dairy cows in herds, (b) the number of adult dairy cows contributing to BTM samples, and (c) the size of the total area of grassland, with positive farms having larger numbers in each case. There was no difference (P > 0.05) between positive and negative farms in (a) the grazing of dry cows together with replacement cows, (b) whether or not grazed grassland was mowed for conservation, (c) the type of drinking water provision system, (d) spreading of cattle manure on grassland or (e) for grazing season length (GSL; mean = 262.5 days). Also, there were differences (P < 0.001) between drainage statuses for GSL with farms on good drainage having longer GSL than moderately drained farms. The GSL for dairy cows on farms with good drainage was 11 days longer than for those with moderate drainage (P < 0.001). The percentage of farmers that used an active ingredient during the non-lactating period against liver fluke, gastrointestinal nematodes, lungworm, and rumen fluke was 96%, 85%, 77% and 90%, respectively. Albendazole was the most frequently used active ingredient for treatment against gastrointestinal nematodes (57%), liver fluke (40%) and lungworm (47%), respectively. There was a difference (P < 0.05) in the use of triclabendazole and albendazole between positive and negative farms, with triclabendazole use being more common in positive farms. This study highlighted differences in dairy management practices between Irish farms with dairy herds exposed or not exposed to liver fluke and stressed the need of fine-scale mapping of the disease patterns even at farm level to increase the accuracy of risk models. Also, comprehensive advice and professional support services to farmers on appropriate farm management practices are very important for an effective anthelmintic control strategy.     

Effects of pistachio by‐products on digestibility,milk production,milk fatty acid profile and blood metabolites in Saanen dairy goats

The objective of this study was to investigate the effects of pistachio by‐products (PBP) on nutrient digestibility, blood metabolites and milk fatty acid (FA) profile in Saanen dairy goats. Nine multiparous lactating Saanen goats (on day 90 post‐partum, 45 ± 2/kg BW) were randomly assigned to a 3 × 3 Latin square design with three treatment diets: 1) control diet (alfalfa hay based), 2) 32% PBP and 3) 32% PBP + polyethylene glycol (PEG‐4000; 1 g/kg dry matter). Each period lasted 21 days, including 14 day for treatment adaptation and 7 day for data collection. Pistachio by‐products significantly decreased (p < 0.01) crude protein (CP) digestibility compared with the control diet (64.4% vs. 58.7%), but PEG addition did not differ for CP digestibility of goats fed 32% PBP + PEG and those fed the two other diets. The digestibility of NDF tended (p = 0.06) to decrease for goats fed PBP compared with those fed the control diet. Yields of milk and 4% fat‐corrected milk were not affected by dietary treatments. Compared with the control diet, PBP supplementation appreciably changed the proportions of almost all the milk FA measured; the main effects were decreases (p < 0.01) in FA from 8:0 to 16:0 and increases (p < 0.01) proportions of cis‐9, trans‐11 18:2 and trans‐11 18:1, monounsaturated FA, polyunsaturated FA and long‐chain FA. The saturated FA, short‐chain FA and medium‐chain FA proportions were lower (p < 0.01) in goats fed the two PBP supplemented diet than in those fed the control diet and PEG addition led to intermediate proportions of saturated FA, unsaturated and monounsaturated FA. Inclusion of PBP in the diet decreased (p < 0.01) plasma concentrations of glucose and urea nitrogen compared with the control diet. It was concluded that PBP can be used as forage in the diet of dairy goats without interfering with milk yield. Inclusion of 32% PBP in the diet of dairy goats had beneficial effects on milk FA profile but PEG addition to PBP did not contribute to enhance further milk FA profile.     

四川省部分地区山羊沙门氏菌健康带菌率及耐药性调查

为了解四川省山羊沙门氏菌带菌情况,本试验采集了四川省部分地区5个规模化山羊养殖场表观健康山羊粪便196份,经BPW预增菌、TTB选择性增菌后,采用靶向invA基因的PCR方法检测沙门氏菌的带菌率;对阳性样本进行细菌分离鉴定,随机选择25株沙门氏菌分离株测定其对15种抗菌药物的敏感性。结果显示,山羊沙门氏菌的平均带菌率为54.59%。药敏试验结果显示,分离株均对丁胺卡那敏感,而对其余14种抗菌药物呈不同程度的耐药,多重耐药菌株占88%,其中耐2~7种药物的占52%,耐9~13种药物的占36%。结果表明,四川省部分地区山羊的沙门氏菌健康带菌率较高,且多重耐药性普遍,其公共卫生意义值得进一步研究。