亚临床酮病对泌乳早期奶牛繁殖性能和血液生化指标的影响

试验旨在探究围产期亚临床酮病与泌乳早期奶牛繁殖性能、卵泡发育之间的关系,并检测试验牛血液生化指标的变化。试验在黑龙江某大型集约化牛场开展,根据产后血酮水平确定亚临床酮病组（SCK）和健康组（C）奶牛共60头,根据试验牛产后50 d内发情状况,将SCK组再分为发情组（SCKE,16头）和乏情组（SCKA,14头）,C组也同样分为发情组（CE,25头）和乏情组（CA,5头）。所有试验牛在产后50 d通过直肠检查和B超检查了解子宫复旧及卵泡发育状况,记录繁殖性能数据,并进行血液生化指标分析。结果表明：与健康组发情奶牛相比,亚临床酮病发情奶牛产后首次发情日期推迟约10 d（P<0.05）;产后50 d卵泡直径差异极显著（差值约4 mm）（P<0.01）。亚临床酮病乏情奶牛子宫复旧延迟发生率显著高于健康组发情奶牛（P<0.05）;亚临床酮病奶牛血浆中胰岛素样生长因子-1（IGF-1）含量显著低于健康奶牛（P<0.05）,而泌乳量极显著提高（P<0.01）。与发情奶牛相比,乏情奶牛血浆中甘油三酯（TG）含量显著升高（P<0.05）;葡萄糖（Glu）、胰岛素（Ins）、雌二醇（E₂）、孕酮（P₄）含量显著或极显著降低（P<0.05;P<0.01）。综合以上试验结果,奶牛患亚临床酮病而导致能量代谢指标异常是引起奶牛乏情、产后卵泡发育受阻和繁殖障碍的主要因素,进而导致奶牛繁殖力下降。     

亚临床酮病对荷斯坦奶牛产后疾病、繁殖性能及产奶量的影响

本试验旨在研究亚临床酮病对奶牛产后疾病、繁殖性能及产奶性能的影响.选择产后1～2周的荷斯坦泌乳奶牛807头,其中酮病组336头(1胎样本数量134头,2胎样本数量104头,3胎样本数量98头),正常组471头(1胎样本数量262头,2胎样本数量78头,3胎样本数量131头).统计每组牛只产后真胃移位、淘汰、配次、受胎率...     

乌兰察布市泌乳奶牛亚临床酮病的调查研究

试验选取内蒙古乌兰察布市489头泌乳奶牛,通过对尿中和乳中酮体采用酮粉法检测进行奶牛亚临床酮病的监测与分析。结果表明,乌兰察布市泌乳奶牛亚临床酮病发病率为10.63%;第1和第2个泌乳月亚临床酮病发病率明显高于第3个及以上泌乳月;各胎次亚临床酮病发病率以3～5胎最高;日产奶量在30kg以上亚临床酮病发病率显著高于日产奶量在30kg以下奶牛;养殖小区以及规模户饲养奶牛的亚临床酮病发生率较高。     

奶牛亚临床酮病检测

本研究采用试纸条法、紫外分光光度法和酮粉法检测奶牛亚临床酮病,结果表明：以紫外分光光度法定量检测结果为诊断标准,试纸条法具有较高的敏感性和特异性,分别为69％和94％,酮粉法的检测敏感性和特异性较低,分别为56％和90％.     

亚临床型酮病对奶牛健康和生产性能的影响

酮病对奶牛的机体健康和生产性能具较大损伤,若不及时治疗会导致提前淘汰。根据临床特征不同,主要分临床型酮病和亚临床型酮病。亚临床型酮病临床症状不明显,隐秘性强,多发于高产奶牛,若不及时治疗会造成较大影响,带来经济损失。该病原因较多,部分养殖人员认知较差,不利于防控。本文对亚临床型酮病发病原因、特点、临床诊断手段和对奶牛健康危害综合概述,有利于养殖人员更好了解该病,降低损失,促进奶牛养殖业健康发展。     

雅安市泌乳奶牛亚临床酮病的调查

随着我国奶牛业的发展,尤其是奶产量的提高,奶牛酮病(尤其是亚临床酮病)的发病率有上升的趋势,已引起国内兽医学者的普遍关注。临床上,亚临床酮病虽无明显的症状,但由于会引起母牛泌乳量下降,乳质量降低,体重减轻,生殖系统疾病和其他疾病发病率增高,而造成严重的经济损失。本研究采用酮粉法检测雅安市养殖场和散养农户泌乳奶牛尿、乳酮体,了解雅安市奶牛在不同自然饲养管理条件下亚临床酮病的发生情况,为寻求预防和控制雅安市亚临床酮病的适宜时机和方法提供科学的理论依据。1材料与方法1.1实验奶牛雅安市各奶牛场及农户散养的泌乳奶牛536头…     

围产期奶牛亚临床酮病的生化诊断

本研究分析比较了产后初期亚临床酮病奶牛和健康奶牛血清葡萄糖、非酯化脂肪酸、-羟丁酸、铜和锌的代谢水平,以期进一步完善奶牛亚临床酮病的生化诊断。结果表明,与健康奶牛相比较,亚临床酮病奶牛的血清非酯化脂肪酸和-羟丁酸含量显著升高,而葡萄糖和锌含量显著降低,铜含量无显著差异。揭示血清葡萄糖、非酯化脂肪酸和锌含量可作为奶牛亚临床酮病生化诊断的参考指标。     

亚临床酮病对围产期奶牛生产性能和血液糖脂代谢指标的影响

为研究奶牛亚临床酮病与生产性能的关系,研究选择2～4胎次中国荷斯坦奶牛,根据产后血液中β-羟丁酸(BHBA)水平将奶牛分为亚临床酮病组(SCK组,16头)和健康对照组(C组,20头),记录围产期奶牛体况(BCS)和产后1～8周的泌乳量,分析产后第60 d乳成分变化;并于产前21、14、7 d和产后1、3、5、7、14、21 d分别进行血液样本检测,分析围产期奶牛血液中游离脂肪酸(NE-FA)、血糖(GLU)、三酰甘油(TG)、总胆固醇(CHO)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、胰高血糖素(GC)、胰岛素(INS)水平的变化。结果表明:与健康对照组奶牛相比,SCK组奶牛血液中BHBA浓度在产后3～21 d显著高于C组(P<0.05),1～8周泌乳量低于C组,但差异不显著(P>0.05),乳样中乳脂率和脂蛋比显著高于C组(P<0.05)。血液样本分析表明SCK组奶牛血液NEFA在产后7、14 d显著高于C组(P<0.05),GLU水平在产后3、5、7、21 d显著低于C组(P<0.05);SCK组奶牛血液中TG、CHO、HDL-C有所下...     

不同方法检测奶牛亚临床酮病的比较

本文以试剂盒测血清β-羟丁酸含量大于1.2mmol/L作为亚临床酮病奶牛的诊断标准,采用酮粉法、试剂法、ROSS法和试纸法分别对血酮、乳酮和尿酮含量进行检测,并将定性检测的结果与定量检测的结果相比较。结果表明,酮粉法测血酮的符合率最高、为88.54%;试纸法测尿酮次之、为87.50%;ROSS法测尿酮的符合率和阳性率最低,分别为79.17%和13.54%。酮粉法测血酮敏感性最高,为70.37%;ROSS法测尿酮的敏感性最低,为37.04%;试剂法测乳酮、ROSS法测尿酮和试纸法测尿酮三者的特异性均为95.65%,高于酮粉法测血酮的特异性(94.20%),酮粉法测尿酮特异性最低、仅为88.41%。从操作难易度和成本上考虑,酮粉法测定乳酮含量比较适合牧场亚临床酮病的检测。     

围产后期亚临床酮病对奶牛氧化应激、免疫功能和生产性能的影响

试验旨在研究围产后期SCK奶牛机体是否产生了氧化损伤和炎症反应。试验选取胎次、体重、上一胎次产奶量接近的产前(5±2) d的50头临床检查健康的荷斯坦奶牛为试验动物,根据产后10 d奶牛血液中BHBA含量是否在1.2～3.0 mM范围内,选取其中10头奶牛作为对照组(健康奶牛,n=10),10头奶牛作为SCK组(n=10)。分别于产后第10 d、20 d早晨饲喂前采集尾静脉血液用于测定SCK参数(BHBA、NEFA)、氧化参数、抗氧化参数、炎性因子、生产性能。结果表明,SCK组奶牛血液中SCK参数(BHBA、NEFA)、肝功能指标(AST、ALT、ALB、CHOL和TG)、氧化参数(ROS、MDA和H_2O_2)、炎性因子(TNF-α、IL-1β、IL-2、IL-8和IFN-γ)和SCC在产后10 d和20 d均显著高于对照组(P<0.05),且随着泌乳时间的延长,SCK组奶牛产后20 d时以上所述参数仍显著高于对照组产后10 d的奶牛(P<0.05);而GLU含量、IgG含量、抗氧化参数(TAC、SOD和GPX)、DMI和产奶量在产后10 d和20 d则显著低于对照组(P<0.05),且随着泌乳时间的延长,SCK组奶牛产后20 d时以上参数仍显著低于对照组产后10 d的奶牛(P<0.05)。综上所述,奶牛在产后20 d内机体产生了亚临床酮病,SCK奶牛肝脏均产生了不同程度的氧化损伤和炎性损伤,显著降低了奶牛的生产性能和健康状况。     

植物甾醇对泌乳前期奶牛生产性能及血浆生化指标的影响

本试验旨在研究添加不同剂量植物甾醇对泌乳前期荷斯坦奶牛生产性能及血浆生化指标的影响。选用泌乳期相近的健康荷斯坦奶牛24头,随机分成4组,每组6头,Ⅰ组为空白对照组,饲喂基础日粮,Ⅱ、Ⅲ、Ⅳ组分别在基础日粮中添加200、400和800 mg/d植物甾醇,研究不同添加量的植物甾醇对奶牛生产性能及血液生化指标的影响。结果表明：①各试验组血浆生化指标Ⅱ组变化最为明显。较Ⅰ组而言,Ⅱ组血浆雌激素、孕酮、催乳素、卵泡刺激素、黄体生成素、干扰素、白细胞介素2、高密度脂蛋白胆固醇均显著提高（P＜0.05）,丙二醛含量显著下降（P＜0.05）。②较Ⅰ组而言,Ⅲ组血浆白细胞介素2、高密度脂蛋白胆固醇均显著提高（P＜0.05）。③与Ⅰ组相比,Ⅳ组血浆甘油三酯含量明显下降（P＜0.05）,总超氧化物歧化酶显著提高（P＜0.05）。添加植物甾醇可提高奶牛的泌乳量,改善奶牛内源激素不平衡的状况,并促进奶牛发情,改善奶牛脂类代谢情况,改善奶牛体质,其中200 mg/d植物甾醇添加量为最适添加量。     

An economic analysis of hyperketonemia testing and propylene glycol treatment strategies in early lactation dairy cattle

The purpose was to develop stochastic economic models which address variation in disease risks and costs in order to evaluate different simulated on-farm testing and propylene glycol (PG) treatment strategies based on herd hyperketonemia (HYK) incidence during the first 30 DIM. Data used in model development concerning the difference in health and production consequences between HYK and non-ketotic cows were based on results from 10 studies representing over 13,000 cows from 833 dairy farms in North America, Canada, and Europe. Inputs for PG associated variables were based on a large field trial using cows from 4 free-stall dairy herds (2 in New York and 2 in Wisconsin). Four simulated on-farm testing and treatment strategies were analyzed at herd HYK incidences ranging from 5% to 80% and included: 1) treating all cows with 5 d of PG starting at 5 DIM, 2) testing all cows for HYK 1 day per week (e.g. Mondays) from 3 to 16 DIM and treating all positive cows with 5 d of oral PG, 3) testing all cows for HYK 2 days per week (e.g. Mondays and Thursdays) from 3 to 9 DIM and treating all positive cows with 5 d of oral PG, and 4) testing all cows for HYK 3 days per week (e.g. Mondays, Wednesdays, and Fridays) from 3 to 16 DIM and treating all positive cows with 5 d of oral PG. Cost-benefit analysis included the costs associated with labor to test cows, β-hydroxybutyrate test strips, labor to treat cows, PG, and the associated gain in milk production, decrease in DA and early removal risks of PG treated HYK positive cows compared to non-treated HYK positive cows. Stochastic models were developed to account for variability in the distribution of input variables. Per 100 fresh cows in a herd with an HYK incidence of 40%, the mean economic benefits of the 4 different strategies were $1088, $744, $1166, and $760, respectively. Testing cows 2 days per week from 3 to 9 DIM was the most cost-effective strategy for herds with HYK incidences between 15% and 50%; above 50%, treating all fresh cows with 5 d of PG was the most cost-effective strategy. These results show that for herds similar to those used in model, when herd HYK incidences rise above 25%, almost any HYK testing and treatment protocol will be economically beneficial for the farm.     

奶牛酮病发病原因及其对生产性能影响调查分析

探索奶牛酮病发病原因、发病规律及其对生产性能的影响,对986头围产期奶牛进行跟踪调查分析。结果表明,奶牛酮病发病率为31.74%,死亡率为4.15%;秋季发病率最高,可达37.4%,其次是冬季和夏季,春季发病率最低;随着胎次、年龄和产乳量的增加,奶牛酮病的发病率明显增高;在第1个泌乳月奶牛酮病的发病率最高,可达50.43%;日粮种类和微量元素越少,奶牛酮病就越容易发生;奶牛发病后受胎率明显降低;发病后产乳量、乳脂率、乳蛋白率、乳糖率和乳干物质比发病前均明显降低,差异显著（P〈0.05）。奶牛酮病发病具有一定的规律性,且可降低奶牛的繁殖性能、产奶量和乳品质。     

Managerial practices and factors influencing reproductive performance of dairy cows in urban/peri-urban areas of Kampala and Gulu,Uganda

Background

Urban/peri-urban dairy production and sales has evolved as an adjustment to cope with food security and economic needs for urban dwellers in low-income countries and created an opportunity to transform from subsistence rural lifestyles of dairy farming to commercial engagement in towns. However, urban/peri-urban dairy farms differ in challenges from rural dairy farms and reproduction is important and critical for assuring sustainable economic output in both environments. Here we recorded for the first time differences between two geographically and economically different cities corresponding to different settings within the same country in managerial factors influencing reproductive performance in urban/peri-urban dairy cowherds.

Results

The urban/peri-urban dairy farmers in the capital Kampala were more often male (P = 0.002) and commercialized (P = 0.0025), more experienced (P = 0.0001) and practiced zero-grazing more often (P = 0.05) than in the regional municipality Gulu. Also, the milk production per herd and cow (P = 0.0005) and calving rate were (P = 0.0001) higher in Kampala and artificial insemination was more commonly (P = 0.002) used than in Gulu. There was no difference in abortion nor neonatal mortality rate between the two locations. Overall, calving rates were higher (P = 0.0003) in smaller (≤3 dairy cows) and open grazing (P = 0.003) herds. Abortion rates were higher among dairy herds practicing late (≥5 months) (P = 0.003) calf weaning and in herds with commercial purposes (P = 0.0001). Neonatal calf mortality was lower (P = 0.01) in small herds.

Conclusion

The study showed significant differences between Kampala and Gulu in reproductive performance and related husbandry factors for cows in the urban/peri-urban dairy farming systems. For several reproductive performance traits we found associations with husbandry and production traits, which should be taken into account when providing advice to the urban and peri-urban dairy farmers in the tropics.     

Influence of low phosphorus intake during early lactation on apparent digestibility of phosphorus and bone metabolism in dairy cows

In this study, the effects of reducing the dietary phosphorus (P) supply during the first 4 months of lactation on P balance and bone metabolism were investigated in dairy cows during a full lactation, including the dry period. Twenty-two multiparous cows of the Swedish Red and White Breed were included in the experiment. Eleven cows received a dietary P concentration of 0.43% of DM during the whole lactation (NP), and 11 cows received a dietary P concentration of 0.32% of DM during the first 4 months of lactation, followed by 0.43% of DM during the rest of lactation (LP). Total collection of faeces was carried out during five different stages of lactation, for 5 consecutive days at each occasion. The dynamics of bone metabolism was investigated by monitoring one bone-formation marker, identifying osteocalcin (OC), and one bone-resorption marker identifying C-telopeptide fragments of collagen type I (CTx) in blood plasma. At the two first collection periods, 3–7 and 11–15 weeks after parturition, the apparent digestibility of P was higher in the LP cows (52%) than in the NP cows (42%). During the following collection periods, no difference in the apparent digestibility could be noted between the two groups of cows. Phosphorus retention did not differ between treatments at any collection period. The highest retention was observed during late lactation and during the dry period. The profiles of the bone metabolism markers indicated a net resorption of bone during early lactation, but there were no differences in marker concentrations between the groups during early lactation, indicating that the LP diet did not induce a further elevated net bone resorption.     

Effect of feeding on reproductive performance in Finnish dairy cows

The effect of 2 types of feeding on the involution of the genital tract and on the fertility was studied in 79 Finnish dairy cows on a research farm. The cows were fed twice a day with home-produced feed in accordance with the Finnish feeding standard. The cows were divided according to the type of feed into a hay-urea group and a silage group. The cows were examined clinically by rectal palpation 3 times a week during 8 weeks postpartum. The time required for the complete involution of uterus and cervix was recorded. The cows in the silage group had a significantly longer time in uterine involution, a lower fertility rate at first insemination and a longer interval from calving to conception than those in the hay-urea group. The pregnancy rate in the first insemination was in the hay-urea group 91% and in the silage group 57%. The interval between calving and the first insemination was shorter in the hay-urea group than in the silage group: 71.4 +/- 10.6 and 74.0 +/- 10.3 days, respectively. The interval between calving and conception was in the hay-urea group significantly (p less than 0.01) shorter than in the silage group; 74.8 +/- 15.1 and 89.5 +/- 24.4 days, respectively.     

大剂量HCG静注法治疗奶牛卵泡囊肿的试验

我们对黑龙江省八五一农场和八五六农场46头患有卵泡囊肿的奶牛进行了4种治疗方法的对比试验,试验结果表明:大剂量HCG静脉注射组(12/15)效果优于HCG肌肉注射2000单位组(4/9)、肌注LHR2000微克组(8/12)和LH肌注200单位组(6/10)。     

引发奶牛乏情的疾病研究进展

奶牛乏情是指产后60～90 d没有发情表现的经产奶牛及14～18个月龄不发情的育成牛,机体不表现出任何明显的发情状态,导致卵泡发育不良,从而影响机体排卵,引起发情周期紊乱、妊娠推迟,这对奶牛业的发展产生重大的影响。本文主要综述奶牛出现乏情状态的繁殖性疾病的研究状况,为进一步研究奶牛产后乏情提供理论依据。     

Study of reproductive performance and related factors in four dairy herds in Fars province (southern Iran) by Cox proportional-hazard model

Our objective was to characterize the current reproductive performance and factors which may be related to it in the Fars province dairy herds in southern Iran. We collected retrospective data from four commercial herds in the region. All 256 cows with history of calving between 21 March 2004 and 20 March 2005 were followed until subsequent pregnancy, culling or death. Effects of risk factors on days open were investigated in a Cox proportional-hazards model. The overall median calving interval, dry period and days open were 388, 68, and 120 days, respectively. First-service conception risk and overall-service conception risk were 45 and 42%, respectively. Average numbers of insemination per pregnant and all cows were 2 and 2.1, respectively. Cows without incidence of any disorder during the lactation (but before conception, and including metabolic disorders) had 2.1-times greater hazard of conception than cows with incidence of disease. No significant association between calving interval, dry period, parity of dam, and sex and weight of calves with days open was observed.     

Effect of prepartum compensatory nutrition regimen on metabolism and performance of dairy cows

The impact of closely controlled energy management during the dry period upon general peripartum metabolism and the subsequent lactation was evaluated in multiparous dairy cows. Eight lactating, pregnant Holstein cows were paired according to current milk production and body condition score and assigned to either the control or the stair-step compensatory nutrition (SSCN) regimen 16 weeks prior to expected calving date. Control cows were fed according to National Research Council [National Research Council., 2001. Nutrient Requirements of Dairy Cattle. 7th rev. ed. Natl. Acad. Sci., Washington, DC.] recommendations and for ad libitum intake during late lactation and the far-off dry period. The SSCN cows were subjected to dietary energy restriction [80% of net energy for lactation requirements (NE_L)] during late lactation in order to maintain body weight, followed by realimentation (130% of NE_L) during the far-off dry period to induce a compensatory response. A common diet was fed thereafter. The SSCN cows gained less body condition during late lactation and tended to gain more body condition during the far-off dry and transition periods than control cows. There was no difference in dry matter intake during the prepartum transition period and early lactation. Milk yield was not affected by treatment. Serum nonesterified fatty acids (NEFA) were not altered by dietary treatment during late lactation and the dry period; however NEFA were lower in SSCN cows at week 4 of the subsequent lactation. Serum insulin was higher in SSCN cows 8 weeks prior to parturition (end of restriction), tended to be higher at 4 weeks (end of realimentation) before calving, and was also higher at week 12 of early lactation. An SSCN regimen stimulated body condition gain of mature dairy cows during the dry period, did not affect periparturient nutrient metabolism, and led to modest improvements in metabolic parameters later in the subsequent lactation.