Excretion of Eimeria Oocysts in Calves During their First Three Weeks After Turn-out to Pasture

The numbers of Eimeria oocysts per gram (opg) and the dry matter content of 449 faecal samples taken from 54 calves in 8 herds in south west Sweden were determined during the last 2 weeks before and the first 3 weeks after the animals were turned out to pasture. While they were housed only between 0 and 580 opg were found and in 2 of the herds the numbers of oocysts remained low after turn-out. In the other 6 herds the numbers of oocysts increased after 8 to 10 days and reached a peak of between 1080 and 80 803 opg 9 to 18 days after turnout. By 21 to 24 days after turn-out the opg-values had declined to their initial levels. Eimeria alabamensis accounted for most of the increase, but small numbers of oocysts of E. auburnensis, E. bovis, E. bukidnonensis, E. cylindrica, E. ellipsoidalis, E. pellita, E. subspherica, E. wyomingensis and E. zuernii were also observed. The interval between turn-out and the start of the increase in excretion of oocysts corresponded closely to the prepatent period of E. alabamensis and overwintered oocysts were therefore the most likely source of the infection. In 6 of the herds the dry matter content of the faeces of the calves decreased after turn-out and 56 % of the calves had clinical diarrhoea. Although it cannot be excluded that change of diet may have contributed to these symptoms, E. alabamensis infection is suggested as a potential cause of diarrhoea and loss of condition in calves in Sweden during their first weeks on pasture.     

Survival of Oocysts of Eimeria alabamensis on Pastures under Different Climatic Conditions in Sweden

The extent to which oocysts of the coccidian parasite Eimeria alabamensis can survive the winter and cause clinical coccidiosis in different parts of Sweden was investigated. Fecal samples were collected between May and July 1993 from calves on 59 farms where calves had grazed the same pasture for at least 5 consecutive years. The farms were situated in 9 regions of Sweden with different climatic conditions in the winter. On each farm, 5 samples of feces were collected from the floor of the calf-house before the calves were turned out in the spring, and again from the pasture on days 4 or 5, 8 or 9 and 10 or 11 after they were turned out. Overwintering of oocysts of E. alabamensis was considered to have occurred if an increase in the excretion rate of oocysts of this species could be demonstrated 8 to 11 days after calves had been turned out to pastures that had not been grazed since the previous autumn. Oocysts were shown to have overwintered on 27 farms, representing all 9 regions. Samples from 20 (34%) of the farms representing all the climatic regions contained more than 850000 oocysts per g of feces. This was comparable with the numbers found in animals with clinical coccidiosis due to E. alabamensis. Delaying turnout until the beginning of July did not affect the infection rate of the calves. However, calves which were turned out to pastures that had been grazed by older cattle or horses, either earlier in the spring or in previous years, excreted significantly fewer oocysts than calves which were turned out to pastures that had been grazed only by calves. A questionnaire answered by 321 dairy farmers revealed that of the 298 farmers who turned their first-season grazing cattle out to traditional pastures, 179 (60%) had used the same pasture for at least 5 years. These 179 farmers had experienced a significantly higher incidence of diarrhoea in their calves during the first 2 weeks at pasture than those farmers who had used different pastures.     

利用DHI对两个奶牛场奶牛生产性能的综合分析

应用DHI(dairy herd improvement奶牛牛群改良)测定体系,对杨凌某奶牛场和西安某奶牛场2007年的5、6、7月份生产情况进行分析,结果表明:这两个牛场的奶牛患有严重的乳房炎或隐性乳房炎;泌乳高峰期到达时间晚;存在着潜在的奶量损失;产犊间隔过长。针对以上问题,提出了相应的改进措施。     

新疆北疆地区犊牛球虫感染调查及虫种鉴定

为了解新疆北疆地区奶牛养殖场犊牛球虫的感染情况,对昌吉、石河子、奎屯地区6个大型奶牛养殖场一岁以内荷斯坦奶牛犊牛球虫感染情况进行了调查。结果发现,犊牛球虫总感染率达到35．55％,其中0～6月龄犊牛平均感染率达42．25％,7～12月龄犊牛平均感染率达21．74％。经虫种鉴定,共鉴定出5种艾美耳属球虫,分别是邱氏艾美耳球虫（Eimeria zurnii）、牛艾美耳球虫〔Eimeria bovi〕、椭圆艾美耳球虫（ Eimeria ellipsoidall）、柱状艾美耳球虫（ Eimeria cylindrica ）、亚球形艾美耳球虫（ Eimeria subspherica）,其中邱氏艾美耳球虫、椭圆艾美尔球虫和牛艾美耳球虫为优势种。调查为新疆北疆地区犊牛球虫的科学防控提供了流行病学资料。     

鸡巨型艾美耳球虫单卵囊分离及雏鸡扩增试验

采用饱和食盐水漂浮法收集就诊病死球虫阳性鸡小肠中段内容物中的球虫卵囊,恒温培养至孢子化后,用2%琼脂薄板进行球虫单卵囊分离,分别感染7只5日龄雏鸡,对据形态学鉴定为巨型艾美耳球虫的分离株进行2代单卵囊分离和雏鸡感染,取其后代以每只1.0×10⁴个卵囊感染10只10日龄雏鸡进行卵囊扩增,获得大量纯种巨型艾美耳球虫卵囊。结果表明,刀片切割琼脂薄板单卵囊分离法操作简便,单卵囊感染成功率较高,准确率达100%,适用于纯种卵囊的分离与扩增。     

Factors Affecting the First Service Conception Rate of Cows in Smallholder Dairy Farms in Bangladesh

The successful outcome of an insemination is a combination of both male and female fertility‐linked factors. We investigated the first service conception rate of cows at artificial insemination (AI) in the smallholder dairy farms in Bangladesh. Frozen straws were prepared from ejaculates of Bos indicus (n = 7) and Bos indicus × Bos taurus (n = 7) AI bulls. Fertility was determined from 6101 first services in cows that were performed by 18 technicians in four regions between April 2004 and March 2005. Pregnancy was diagnosed by rectal palpation between 60 and 90 days post‐insemination. The Asian version of Artificial Insemination Database Application (AIDA ASIA) was used for bulls‐, cows‐ and AI‐related data recording, and later retrieved for analysis. The mean ± SD number of inseminations performed from individual bulls and their conception rates were 436.0 ± 21.6 and 50.7 ± 1.9%, respectively. Logistic regression demonstrated body condition scores (BCS), heat detection signs, months of AI and their interactions had greatest effects (odds ratios: 1.24–16.65, p < 0.04–0.001) on first service conception rate in cows. Fertility differed (p < 0.02–0.001) between the regions, previous calving months, months of AI, BCS, parity and heat detection signs of cows. Inseminations based on mounting activity (n = 2352), genital discharge (n = 3263) and restlessness and/or other signs (n = 486) yielded a conception rate of 53.6%, 48.8% and 50.1%, respectively (p < 0.05). Conception rate between technicians ranged between 43.4% and 58.6% (p < 0.05). The days interval from calving to first service (overall mean ± SD = 153.4 ± 80.6) had relationship (p < 0.001) with BCS, months of previous calving and parity of the cows. Fertility at AI in smallholder farms can be improved by training farmers on nutrition and reproductive management of the cows.     

Survival Analysis of Calves and Reproductive Performance of Cows in Commercial Dairy Farms in and Around Addis Ababa,Ethiopia

A study was conducted at five locations to determine the survival rate of calves and to estimate the performance level of improved dairy cows under commercialized farming systems in Ethiopia. Seven hundred and one calves born from 1997 to 1999, and 797 cows were included in the study. Cumulative calf/heifer survival at 360, 540 and 720 days was 80%, 76% and 70%, respectively. Number of services per conception averaged 2 while mean age at first service and days open were 850+/-18 and 192+/-11 days, respectively. Calf survival, days open and age at first service were significantly affected by breed and management factors (p <0.05), whereas parity significantly affected the number of services per conception and days open. There was a tendency towards improved performance over the years. This was especially so for calf survival and days open. Clearly, all the traits measured varied among study farms, indicating that substantial improvement can be achieved through better management. This paper describes these individual traits of improved dairy breeds under commercialized farming systems in Ethiopia.     

氧化应激对围产期奶牛及犊牛的影响研究进展

围产期奶牛要承受由妊娠、产犊及泌乳3个阶段交替带来的生理性变化,此时奶牛既要维持后期胎儿的正常生长发育,还要保证随后泌乳正常,此阶段发生的生理变化以及能量负平衡很容易诱发奶牛的氧化应激反应.机体组织和细胞持续的氧化应激不仅损害围产期奶牛的生产性能,还会给胎儿带来生理和行为上的危害,影响后代终身生理进程及繁殖机能.本文对...     

牧场犊牛发病次数与生长发育的关系

通过对全国157 个规模化牧场在2020年1—12 月出生的220 日龄内母犊牛各阶段发病次数、体重和日增重进行分析,旨在研究犊牛不同阶段发病次数对其后期体重、日增重的影响。结果表明:(1)断奶前后,60 日龄内发病次数≥2 次的犊牛,61~129 日龄体重、日增重极显著低于未发病犊牛和发病次数为1 次的犊牛(P<0.01);(2)转育成时,60 日龄内发病次数≥2 次的犊牛,转育成171~219 日龄体重极显著低于未发病犊牛和发病次数为1 次的犊牛(P<0.01);60~179 日龄发病次数≥1 次,转育成171~219 日龄体重和转育成日增重极显著低于未发病组(P<0.01)。因此,犊牛发病次数越多,后期生长发育越缓慢,建议牧场重视并加强犊牛断奶前后和转育成的饲养管理,做好疾病防治,以减少发病次数。     

感染鸡日龄对球虫单卵囊分离的影响

选用5、8、11日龄的雏鸡进行鸡球虫单卵囊分离试验,研究不同感染日龄对鸡球虫单卵囊分离的影响。结果表明:在其他条件一致的情况下,从感染成功率、潜伏期、高峰期的出现时间及持续时间和从每只感染雏鸡收集到的球虫卵囊数量等指标进行综合判定,发现感染11日龄的雏鸡单卵囊分离成功率最高。     

肉桂醛对奶牛尿中嘌呤衍生物排出量、产奶性能和氮排泄的影响

本试验旨在研究肉桂醛(CA)对奶牛尿中嘌呤衍生物排出量、产奶性能和氮排泄的影响。选用年龄、体重、胎次、产奶量、乳成分及泌乳期[(90±15)d]相近的荷斯坦奶牛40头,随机分成4个组,每组10头。对照组和试验1、2、3组分别在饲粮中添加0、12、18和24 g/(d·头)肉桂醛。预试期15 d,正试期60 d。结果表明:1)各试验组尿中嘌呤衍生物排出量均极显著高于对照组(P0.01),试验1、2、3组分别比对照组提高了14.22%、17.62%、10.49%。2)各试验组产奶量均显著或极显著高于对照组(P0.05或P0.01),试验1、2、3组分别比对照组提高了10.80%、12.15%、6.48%;试验1、2组的乳脂率均极显著高于对照组(P0.01),各试验组乳蛋白率均极显著高于对照组(P0.01),各试验组乳体细胞数均极显著低于对照组(P0.01)。3)各试验组氮总排泄量均极显著低于对照组(P0.01),试验1、2、3组分别比对照组降低了9.76%、14.13%、7.39%。由此可知,在本试验条件下,综合考虑尿中嘌呤衍生物排出量、产奶量、乳成分含量以及氮总排泄量等指标,奶牛饲粮中肉桂醛的适宜添加量为18 g/(d·头)。     

中国规模化牧场后备奶牛饲养管理现状

后备奶牛饲养管理是牧场牛群管理工作的重要组成部分.调研结果显示,在我国规模化牧场中,饲喂常乳的牧场占比最高,为70.6％,饲喂代乳粉的牧场占比达57.7％,并有38.5％的牧场饲喂废弃乳.在牛奶饲喂量方面,有6％的牧场哺乳期喂奶量在300kg/头以下,大部分牧场(48.8％)喂奶量在400～600kg/头之间,也有部分...     

中国规模化牧场后备奶牛疾病与淘汰现状

后备奶牛健康生长对其未来生产性能具有重要影响.调研结果表明,呼吸系统疾病和营养代谢疾病是导致后备奶牛发病的主要原因,占比分别为46.0％和38.4％.而后备奶牛中发病最多的为哺乳犊牛,占比达51.4％.目前,哺乳犊牛发病率正在逐年降低,从2015年的43.3％降至2019年的25.4％.此外调研发现,造成后备奶牛被动淘...     

规模化奶牛场奶牛亚临床型乳房炎流行规律调查

目的 本研究旨在摸清兰考县规模化奶牛场奶牛亚临床乳房炎流行规律,为该病的防控提供参考。方法 采用加州奶牛亚临床乳房炎试验（CMT）方法对3 家规模化奶牛场的547 头泌乳奶牛进行亚临床乳房炎检测,调查该病与奶牛胎次、泌乳期和乳区的关系。结果 奶牛阳性率为20.11%,乳区阳性率为10.88%;1~2、3~4和≥5胎次的奶牛发病率分别为13.37%、20.53%和29.46%;泌乳前期、泌乳中期和泌乳后期发病率分别为15.11%、22.12%和30.89%;乳区阳性率介于8.59%~13.16%。结论 兰考县规模化奶牛场奶牛亚临床型乳房炎的发病率相对较低,与胎次、泌乳期存在正相关,与乳区无明显关系。     

浙江省大型牧场泌乳奶牛饲料阴阳离子平衡调查研究

对浙江省杭州、金华、宁波三地区6个有代表性的大型牧场泌乳奶牛饲料主要原料的Na、K、C1状况进行了调研,并计算了阴阳离子平衡(DCAB)值。结果表明:泌乳奶牛常用饲料主要原料DCAB值均呈阳性;各牧场间精料混合料Na、K、C1和DCAB分别为1.269%、0.910%、1.147%和431meq/kgDM;玉米、豆粕、麸皮Na、K、C1和DCAB分别为0.019%、0.439%、0.086%和96meq/kgDM,0.044%、2.092%、0.104%和521meq/kgDM,0.008%、0.247%、0.110%和36meq/kgDM;苜蓿干草、羊草干草、青贮玉米Na、K、C1和DCAB分别为0.194%、3.175%、0.945%和612meq/kgDM,0.360%、0.735%、0.545%和177meq/kgDM,0.087%、0.1005%、0.688%和120meq/kgDM。同种原料间氯含量差异较大。     

柔嫩艾美耳球虫大配子发育和卵囊的超微结构

利用透射电镜对柔嫩艾美耳球虫大配子发育和卵囊的超微结构进行了观察。结果表明，大配子体和小配子体寄生于相邻的宿主细胞内，相伴产生。大配子体的发育、大配子的形成、受精及卵囊形成均于带虫空泡内完成。大配子体系由末代裂殖子侵入肠上皮细胞后，缩短、长大、变圆而形成，大配子体和大配子外被单位膜，细胞核位于大配子体中央，早期大配子体的细胞核有1个明显的核仁，细胞质内逐渐形成大量成囊体1、成囊体2、大量支链淀粉和脂肪体，成囊体1比成囊体2形成的早。卵囊壁有5'层，内有大量支链淀粉和指肪体。含有大配子体、大配子和合子的带虫空泡内有丰富的泡内小管，它们是大配子体、大配子和合子获得营养物质和排出代谢废物的途径。     

蒸汽压片玉米对奶牛生产性能和氮磷排放影响的研究

本试验旨在研究蒸汽压片玉米对泌乳早期中国荷斯坦奶牛生产性能和氮磷排放的影响.试验采用4×4重复拉丁方设计.将8头泌乳早期中国荷斯坦奶牛随机分为4组,每组2头.4种日粮处理中蒸汽压片玉米含量分别为精料的0、10%、20%和30%.试验分4期,每期28 d.结果表明:日粮中添加蒸汽压片玉米对奶牛干物质采食量无显著影响(P＞0.05),但显著提高了饲料转化率(奶料比)(P＜0.05);显著提高了奶牛产奶量,其中20%与30%组的4%标准奶产量(FCM)产量分别比对照组提高2.78和2.87 kg·d~(-1)(P＜0.01).对乳成分无显著影响(P＞0.05);乳蛋白、乳糖、乳非脂固形物含量呈增加趋势;对营养物质的表观消化率无显著影响(P＞0.05);日粮中添加蒸汽压片玉米显著降低了乳尿素氮水平(P＜0.05).试验组奶牛氮排放量分别比对照组降低了4.23%(P＞0.05)、9.37%(P＜0.05)和10.29%(P＜0.05),磷排放量分别比对照组降低了1.93%(P＞0.05)、2.59%(P＞0.05)和5.19%(P＞0.05).因此,饲喂蒸汽压片玉米能够有效提高奶牛的生产性能,降低氮磷的排放.     

定时输精对奶牛第一情期受胎率的效果分析

[目的]探讨不同月份和精液类型对利用定时输精程序处理奶牛后第一情期受胎率的影响.[方法]选择93头产后60 d以上不发情和产后配1～3次仍未受胎的奶牛,不检查卵巢直接利用激素生源2+1进行同期发情处理.1～3月份处理41头奶牛,6～8月份处理52头;其中,利用性控精液配种58头,常规精液配种35头.[结果]表明:经定时...     

荷斯坦青年牛初次配种妊娠月龄对头胎和二胎产奶量和繁殖性能的影响

旨在研究母牛初次配种妊娠月龄（age at first pregnancy,AFP）对其泌乳性能和主要繁殖性能的影响。本研究以我国北方地区2个规模化奶牛场13 927头荷斯坦母牛（A牧场8 091头,B牧场5 836头）的生产数据为基础,统计了母牛AFP、头胎和二胎的产奶量、产后首次发情时间、首次配种时间和首次受孕时间,然后将母牛根据AFP的早晚（12~19月龄）分为8组,对各试验组母牛的头胎和二胎产奶量和主要繁殖性能的数据进行比较分析。结果表明：1）2个规模化奶牛场荷斯坦青年牛AFP以13和14月龄为主（总占比70.1%）;2）AFP可显著影响荷斯坦青年牛头胎和二胎的305 d产奶量（P<0.05）,其中AFP为14月龄时A牧场头胎和二胎305 d产奶量均最高,分别为15 102和15 534 kg;3）AFP可显著影响荷斯坦青年牛头胎和二胎产后首次发情时间和受孕时间（P<0.05）,AFP为14月龄时头胎产后首次发情和受孕情况最优;4）对于产后首配时间,除A牧场头胎AFP为16月龄时产后首次配种时间显著高于AFP为17月龄时（P<0.05）外,其余各组间均无显著性差异（P ≥ 0.05）,并且各组间配种时间相差≤ 5 d;5）通过对A牧场在场牛（2 703头）与淘汰牛（660头）的AFP记录数据分析发现,在场牛的AFP为14.52月龄,显著高于淘汰牛的AFP（P<0.05）。因此,在北方地区现有的生产管理水平下,14月龄可能是荷斯坦青年牛最适宜的初次配种妊娠月龄,这对我国规模化奶牛场选择荷斯坦青年牛适宜的初次配种月龄具有一定参考价值。