舍饲绵羊产后56 d内乳成分变化规律研究

随着人民生活水平提高和膳食结构调整,绵羊奶必将受到人们的青睐.选取甘肃肉用绵羊新品种群、无角陶赛特和特克塞尔3个品种各8只母羊,对产后1～56 d泌乳理化性质变化进行研究,结果表明：3个品种乳成分及物理性质在第1～3 d变化最为明显,其中乳蛋白含量、非脂固形物含量和酸度3项指标呈现出前期快速下降,中期下降减缓,后期缓慢上升;乳糖指标则呈现出缓慢的前期上升,后期下降的趋势,对选取的3个品种初乳中蛋白、乳脂和可溶性固形物含量等指标对比,依次下降,乳糖含量和密度特克塞尔最高.常乳中除密度外3个品种间差异不显著（P＞0.05）.这为绵羊早期断奶和补饲提供了基础数据.     

湖寒杂交后代母羊产后1～30d泌乳量及乳成分变化规律研究

试验选取21只湖寒杂交(小尾寒羊为母本,湖羊为父本)后代母羊,对其产后1~30 d的泌乳量及乳成分变化规律进行了研究。结果显示:湖寒杂交后代母羊产后1~30 d泌乳性能较高,总泌乳量36.93 kg±2.50 kg,平均日泌乳量1.23 kg±0.08 kg,泌乳曲线方程Y=736x~(0.635)e~(-0.071t);随着泌乳天数的增加,乳的密度、冰点、酸度、可溶固形物、非脂固形物和乳蛋白变化差异均不显著(P0.05);乳糖含量逐渐增加,而酸度、可溶固形物、乳蛋白和乳脂肪的含量基本呈降低趋势(第1天除外)。以上研究结果可为制定舍饲绵羊早期断奶策略及进行科学饲养管理提供基础资料。     

和田多胎红羊泌乳规律初步研究

本研究旨在探明和田多胎红羊泌乳规律,提高双羔成活率。选取6只产双羔和田多胎红羊母羊为试验动物,检测其产后1~28 d泌乳量、乳成分变化规律;测量产后第1天母羊乳房体尺指标,并与泌乳量进行相关性分析。结果显示,和田多胎红羊产后1~28 d总泌乳量为29.87 kg,平均每日泌乳量为1.07 kg,泌乳量在第1~3天上升速度最快,在第21天达到峰值1.23 kg,泌乳曲线方程为：y=537t^0.477e^-0.033t;乳脂、非脂乳固体、密度、乳糖、固形物、蛋白质指标在和田多胎红羊母羊产后1~3 d快速下降,7~28 d趋于稳定,且6项指标第1天与第7、14、21、28天均差异极显著（P<0.01）;和田多胎红羊母羊产后第1天与第14、21、28天的泌乳量之间相关性不显著（P>0.05）,产后第2天与第28天的泌乳量相关性不显著（P>0.05）,其他均显著相关（P<0.05）;母羊产后第1、2、3、7天泌乳量与乳房宽呈显著相关（P<0.05）,母羊产后第14、21、28天泌乳量与乳房体尺指标相关性不显著（P>0.05）。以上研究结果为和田多胎红羊新类群种质特性、选育、饲料配制、羔羊早期断奶等提供理论依据。     

补喂瓜氨酸对妊娠90 d湖羊母羊繁殖性能和泌乳性能的影响

本试验旨在研究补喂瓜氨酸对妊娠90 d湖羊母羊繁殖性能和泌乳性能的影响,为瓜氨酸在湖羊母羊中的应用提供科学依据。试验选取妊娠90 d的湖羊母羊50只,随机分成2组,每组25只。对照组饲喂基础饲粮,试验组在基础饲粮中添加瓜氨酸10 g/d进行补喂。试验一直进行到母羊产后45 d,记录羔羊初生重和45日龄体重。每组选取6只母羊,测定产后16～30 d泌乳量及乳成分变化,采集母羊产后第15、30、45天晨饲前颈静脉血样。结果表明：与对照组相比,试验组羔羊初生重极显著提高了19.6%(P <0.01);试验组羔羊45日龄体重显著提高了6%(P <0.05);试验组母羊产后第16～30天平均日泌乳量和总泌乳量分别极显著提高了19.6%(P <0.01);试验组母羊产后第1天乳蛋白率极显著提高了20%(P <0.01);试验组母羊产后第7～15天以及20～30天乳脂率分别极显著提高了21%和16.7%(P <0.01);试验组母羊产后第15天血浆中催乳素（PRL）含量极显著提高了167%(P <0.01),其血浆中孕酮（P4）含量显著降低207%(P <0...     

影响西农萨能奶山羊产奶性状的非遗传因素分析

本试验旨在探究母羊出生年度、季节、胎次、泌乳阶段4个固定效应对西农萨能奶山羊产奶性状的影响。以西北农林科技大学萨能羊原种场2006-2018年的645只泌乳母羊为研究对象,每月采集乳样1次,采样日早、晚各采集1次,将两次乳样等比例混合后,采用乳成分分析仪测定乳脂率、乳蛋白率、乳糖率、总脂固形物、非脂固形物、密度、冰点和酸度共8个指标,结合羊场产奶量记录,采用固定效应模型,通过SAS 9.4软件进行表型的描述性统计分析,再采用GLM模型进行固定效应对产奶性状的影响分析。结果表明,西农萨能奶山羊平均300 d产奶量为507.67 kg,乳脂率为3.58%,乳蛋白率为3.20%,乳糖率为4.19%;总固形物含量为12.21%,非脂固形物含量为8.46%;出生年度、胎次对产奶量影响极显著（P<0.01）,出生季节对产奶量影响不显著（P>0.05）;泌乳阶段、出生年度对乳脂率等8个乳成分性状均有极显著影响（P<0.01）,胎次对除乳蛋白率和总固形物的其他6个乳成分指标均存在极显著影响（P<0.01）。综合以上试验结果,胎次及泌乳阶段是影响西农萨能奶山羊产奶性状的两种主要非遗传因素,第3、4胎母羊产奶性能最佳,泌乳早期的乳品质更优,揭示了对种群进行良种选育工作和羊饲养管理的重要性,也为后期进行奶山羊经济性状遗传评估和群体遗传改良提供理论基础。     

甘肃高山细毛羊泌乳规律及哺乳期羔羊体重生长规律研究

为探讨舍饲半舍饲条件下甘肃高山细毛羊泌乳规律及哺乳羔羊生长规律,试验以25只二胎次甘肃高山细毛羊泌乳母羊和29只哺乳期羔羊为研究对象,测定母羊2~75d的泌乳量以及哺乳期羔羊1~75d体重变化。结果表明:甘肃高山细毛羊产后2~75d泌乳曲线符合Wood模型;羔羊性别对母羊泌乳量和泌乳曲线方程参数无显著影响(P0.05);羔羊累积生长曲线呈近似直线变化,且羔羊体重增长量与母羊的泌乳量呈极强正相关(r=0.988)。研究结果表明,甘肃高山细毛羊母羊泌乳曲线具有泌乳初期上升速度快,泌乳高峰期出现较早且峰值较高,泌乳后期下降速度较快的特点。羔羊生长规律表现出生后1~10日龄日增重快速增加,11~50日龄日增重平稳上升,50~75日龄日增重波动下降。     

不同月份产羔奶山羊初乳免疫球蛋白和常乳乳成分检测

从产羔母羊初乳免疫球蛋白和泌乳期常乳乳成分角度,对全年不同季节产羔母羊鲜奶质量进行评价。对1月、3月、5月、7月产羔的奶山羊,每批随机选择10只母羊,分别收集母羊产后0d、2d、5d、7d初乳和产后9d及1~6个月的常乳(每月收集一次)。采用酶联免疫吸附法(ELISA)检测初乳液中免疫球蛋白A(IgA)和免疫球蛋白G(IgG)水平,采用全自动乳样分析仪分析常乳样品中乳蛋白、乳脂、乳糖、非脂固形物和总脂固形物的含量。结果表明,1月、3月、5月、7月产羔母羊产后相同泌乳阶段初乳中IgA和IgG含量无显著差异(P0.05),变化趋势一致。不同月份产羔母羊常乳中乳糖含量在相同泌乳期无显著性差异(P0.05),脂肪、蛋白质、非脂固形物和总脂固型物在部分泌乳阶段存在明显差异;在整个泌乳期间,1月、3月、5月、7月产羔母羊常乳中的乳蛋白、乳脂、乳糖、非脂固形物和总脂固形物(干物质)含量%变化趋势一致,其变化范围为3.31%~3.45%,4.91%~5.77%,4.03%~4.20%,8.48%~8.88%,13.72%~15.07%;乳脂和总脂固形物含量偏高,但没有降低羊奶的质量。通过对乳成分含量的检测,为后期调整奶山羊日粮组成以保证不同月份产羔母羊的乳品质提供数据基础。     

奶牛泌乳期间的饲养管理

乳牛在一个泌乳期内其产乳量呈规律性变化。一般在分娩后乳牛的产乳量逐渐上升,低产牛在产后20～30d达到泌乳高峰期,高产牛则在产后40～50d达到泌乳高峰期,泌乳高峰期一般可维持20～60d,由此可见,乳牛在分娩后两三个月其产乳量最高。此后产乳量则逐渐下降,高产牛平均每月下降4%～5%;低产牛每月平均下降9%～10%,尤其在妊娠5个月之后下降幅度更为明显,有些低产牛在泌乳后期甚至会停止泌乳,但高产牛即使在停乳前,日产乳量也不低于10kg。因此,根据泌乳期乳量变化规律,将泌乳牛分为泌乳盛期、泌乳中期和泌乳后期几个泌阶段进行饲养管理。1泌乳盛…     

奶水牛乳中体细胞数与乳成分的相关分析

乳汁体细胞数(somatic cell count,SCC)是检查奶牛乳房炎和牛奶质量的指标,为了解南宁某规模化奶牛场奶水牛SCC情况及SCC与其他乳成分的关系,试验随机选取该场152份泌乳早期乳样,测定其SCC、乳汁比重、蛋白质、脂肪、总固形物、非脂固形物及乳糖的含量,并对其进行相关性分析。结果表明,SCC小于50万/mL的乳样占被检奶样总数的88.16%,大于100万/mL的占1.97%;乳汁比重、乳蛋白、乳糖和非脂固形物含量均随着SCC的升高而下降,而乳脂含量随着SCC的升高而呈上升趋势;SCC与乳糖及非脂固形物含量呈极显著负相关(P<0.01)。因此,奶水牛乳中SCC不仅与乳糖和非脂固形物含量密切相关,也提示其与奶水牛产后营养代谢状况有关。     

“诱乳素”诱导非繁殖季节的空怀萨能奶山羊泌乳的研究

试验选择空怀萨能奶山羊采用"诱乳素"进行诱导泌乳.结果表明;经过短期处理,母羊达到产奶的高峰,但母羊之间有差异(P<0.05).综合比较,经诱导泌乳产奶后,乳汁品质正常,与正常产羔的奶山羊奶汁没有区别.采用相同处理程序对德国内用美利奴绵羊进行处理.结果睥明;虽然母羊开始出现泌乳的时间不同,但达到正常产奶量的时间和达到本品种母羊最高泌乳量的产量无明显差异(P>0.05).采用"诱乳素"处理,萨能奶山羊于处理后13d,德国肉用美利奴母羊于15d出现发情症状,经第二个发情期统一人工授精,已妊娠.实验观察了诱导泌乳生产的山羊奶与普通牛奶对初生的羔羊哺乳补奶的效果.结果表明:给初生羔羊哺乳牛奶,羔羊表现拉稀、生长发育缓慢,羔羊成活率低(P<0.01);使用奶山羊奶哺乳和自然哺乳绵羊奶的羔羊,未出现拉稀,羔羊的成活率达到100%(P<0.01).利用奶山羊诱导泌乳.而后为绵羊羔羊充当保姆,可以大幅度提高羔羊的成活率.实验结果证实,此模式可以应用于生产实践.     

Factors affecting milk yield and composition of Tunisian camels (Camelus dromedarius) over complete lactation

This study aimed to investigate the milk production potential and the impact of nongenetic factors on milk yield and composition of Tunisian dromedary camels. Milk recording and sampling were carried out at monthly intervals over complete lactation for 3 years from 95 camels reared in intensive and semi-intensive systems. The overall means of daily milk yield and fat, protein, total solids, and ash contents were 4.21 ± 1.98 l/day, 2.45 ± 0.9%, 2.67 ± 0.74%, 10.75 ± 1.41%, and 0.85 ± 0.08%, respectively. The total milk yield was 1388.41 ± 575.46 l/lactation for 11 months of lactation. The daily milk yield increased regularly throughout lactation until it reached its peak in the 4th month postpartum and then decreased until the 17th month postpartum. The chemical components, except ash, followed an opposite trend to the milk yield. Their minimum contents were recorded during the 7th and 8th months postpartum, while the maximum levels were observed during the 17th month postpartum. Regarding seasonal variation, the highest daily milk yield was recorded during summer (June), whereas the lowest was found in winter (December). In contrast, the maximum and minimum contents of fat and protein were observed during winter (December) and summer (July), respectively. Similarly, total solids content was maximum in January and minimum in August. Parity had no effect on daily milk yield, while all chemical components were higher in milk from primiparous than multiparous camels. Calf sex and management system did not affect the milk yield and composition. These results are useful in order to develop feeding strategies and breeding programs for improving milk production.

     

Effect of supplemental yeast culture and physiological factors on colostrum and milk composition of Pelibuey ewes

The effects of supplemental yeast culture, litter size, stage and number of lactation on milk composition were studied in Pelibuey ewes. Twenty ewes were randomly assigned to one of two dietary treatments. Ten control ewes grazed on guinea grass (Panicum maximum) and were supplemented with concentrate. A further ten ewes received the same diet with 14 g/head/day of yeast culture (Saccharomyces cerevisiae). Colostrum was collected within 24 h after parturition, and subsequently, milk samples were collected at fortnightly intervals (7, 21, 35, and 49 days). Total solids content averaged 32% in colostrum and 12.5% in milk. Colostrum of primiparous ewes had higher total solids content than that of ewes with more than five lactations. However, ewes with more than five lactations produced milk with higher net energy, total solids, protein, and casein than ewes with fewer lactations. Milk at 7 days had a significantly higher content of energy, total solids, and fat than milk at 21, 35, and 49 days. Total solids content was lower for ewes rearing one lamb than larger litter sizes. Supplementation with yeast culture did not affect the composition of colostrum and milk, which was mainly affected by the stage and number of lactation.     

贵州黑山羊泌乳量的研究

选择分娩贵州黑山羊母羊10只,每5 d记录羔羊吮吸母乳后的体重变化,计为母羊的泌乳量。通过试验研究发现：贵州黑山羊产后60 d日均泌乳量为（464±22）g;泌乳高峰期出现在产后30 d,产后0～30 d泌乳量缓慢上升,随后泌乳量开始逐渐缓慢下降,在泌乳45 d后,日泌乳量下降速度较快。     

Factors affecting the milk yield and composition over lactation of prolific D’man ewes in Tunisian oases

This work aimed to investigate milk potentiality and the influence of some non-genetic factors both on milk yield production and composition in prolific D’man sheep. Observations were performed in eighty lactating D’man ewes maintained under an intensive oases system in Southern Tunisia. Daily milk yield was determined at 7-day intervals using oxytocin?+?hand milking method. Chemical milk composition was determined by Lactoscan. Total productions over lactation (milk, fat, and protein) were estimated using the Fleischmann method. Daily milk yield averaged 1.64?±?0.02 l. It increased to a plateau from the third to the fourth week of lactation, and decreased gradually to the tenth week. D’man ewes produced 128.91?±?3.14 l of milk, 9.23?±?0.26 kg of fat, and 5.26?±?0.12 kg of total proteins. Overall, milk contained 16.17% of total solids, 7.08% of fat, 4.04% of proteins, 4.32% of lactose, 9.09% of solids-not-fat, and 0.73% of ash. Lambing season affected the daily milk yield and milk composition, where fat and total proteins were highest in autumn. Total solids, lactose, solids-not-fat, and ash were higher in winter than in autumn and summer. Ewes reared multiple lambs produced more milk than those reared singles. Dams nursing triplets or more had the highest milk total proteins, and the lowest total solids and fat levels. Adult ewes produced more milk compared to younger and older ewes, and their milk contained higher total solids, fat, and ash levels than milk from young ewes. Ewes with asymmetric udder produced less and more concentrated milk than ewes with symmetrical udder. Daily milk yield was negatively correlated to total solids, fat, and total proteins amounts. In contrast, litter survival at weaning was positively correlated to the amounts of total milk, fat, and total proteins.

     

围产期小尾寒羊血清T-SOD活性和MDA含量变化的研究

[目的]研究围产期小尾寒羊血清T-SOD活性和MDA含量的变化。[方法]选择20只年龄在2~5岁之间的小尾寒羊,其中10只为待产母羊,10只为空怀母羊,分别于产前20d、产前10d、产前1d、产后1d、产后10d、产后20d颈静脉采血,测定血清T-SOD活性和MDA含量。[结果]围产期小尾寒羊在整个围产期内血清中T-SOD活性呈先下降后逐渐升高的动态变化,其中,在产前1d出现最低值且围产期小尾寒羊T-SOD活性均低于空怀小尾寒羊;围产期小尾寒羊在整个围产期内血清中MDA含量呈先上升后逐渐下降的动态变化,其中,在产后1d出现最低值且围产期小尾寒羊MDA含量均高于空怀小尾寒羊。[结论]怀孕和分娩对小尾寒羊T-SOD活性和MDA含量有一定的影响。     

Transmammary transfer of nitrates and nitrites in ruminants and methemoglobin blood levels in the young and their mothers

Transmammary transfer of nitrates was studied in ewes as model animals and in a dairy cow during the colostrum period and shortly after it. Ewes were administered per os 35 mg NaNO3.kg-1 of live weight twice daily during five days post partum and the dairy cow 50 g KNO3 during ten days post partum. Methaemoglobinaemia in ewes and their lambs had consistent dynamics during the whole period of study with slightly higher values in lambs than in ewes. Differences in the averages of methaemoglobin (MtHb) concentrations in blood were statistically higher from the fourth till the 72nd hour after administration. NaNO3 concentration in milk highly and significantly increased after the first administration, with a subsequent decline to an insignificant level during further clays, as compared with the initial data. NO2 ions were not observed to be present in any milk sample. Dynamics of methaemoglobinaemia in the dairy cow and her calf was the same as in the ewes, with a tendency of regular increasing four hours after administration. The increase in methaemoglobinaemia the last day of the trial was at the limit of significance. NaNO3 content in milk significantly increased on the 3rd, 9th and 10th day after administration. Nitrates in urine showed similar trend as in milk with a significant increase only on the 2nd and 10th day post partum. The finding of 14.5 mg.l-1 NaNO3 in the amniotic fluid provides evidence of a simultaneous transplacental transfer of nitrates.     

Behavioral, adrenal, immune, and productive responses of lactating ewes to regrouping and relocation.

The experiment involved 40 mid-lactating Comisana ewes. The animals were housed in straw-bedded pens and assigned to a control group (n = 10) and two test groups of 15 subjects each. Control ewes were never moved from their pen and peers throughout the experiment period, whereas test animals were subjected to either regrouping (RG) or regrouping and relocation (RGRL) three times at weekly intervals (d 7, 14, and 21 of the trial). Three behavioral recordings were conducted after each social and pen exchange over a 6-h period (1000 to 1600). Animals from groups RG and RGRL were bled immediately before each regrouping and relocation and 15 and 60 min afterward. The phytohemagglutinin skin test was performed at d 9, 16, and 23. Milk yield was recorded when the ewes were mixed and moved, and before and after each mixing and moving procedure. Individual milk samples were analyzed for composition, renneting parameters, and bacteriological characteristics; samples with more than 10(6) somatic cells/mL were cultured for mastitis-related pathogens. Control ewes spent more time lying than groups RG (P < 0.001) and RGRL (P < 0.01) and less time in ambulatory activities than RGRL sheep (P < 0.05). Moved and remaining ewes showed a higher number of aggressive interactions than control subjects (P < 0.001 and P < 0.01, respectively). Control sheep showed the highest cell-mediated immune response compared with both moved and mixed ewes (P < 0.001 and P < 0.01, respectively). The RGRL ewes gave lower yields of milk than did the control ewes on the days after the first (P < 0.05) and the second (P < 0.01) change of pen and peers. The RGRL ewes also had a lower fat content (P < 0.05) than control ewes in the milk yielded on the day of the first regrouping and relocation and a lower milk protein content (P < 0.05) on the following day. The RG treatment resulted in the ewes yielding milk with a lower fat content (P < 0.01) on the day of each mixing procedure as compared with controls and in a decreased milk protein content on the days after the first (P < 0.05) and the second regrouping (P < 0.01). One case of subclinical mastitis was recorded in both the RG and RGRL groups, whereas no cases were detected in control group. These findings suggest that regrouping and relocation may cause increased aggression, altered immune responses, and short-term effects on the production performance of lactating ewes. These practices should be performed by attempting to minimize their impact on animal welfare.     

共轭亚油酸诱导的奶牛低脂乳症中脂肪球膜甘油磷脂的组成差异分析

旨在分析共轭亚油酸(CLA)诱导奶牛低脂乳症对牛乳脂肪球膜甘油磷脂含量的影响.选取体况相近、泌乳中期的10头荷斯坦奶牛进行自身前后对照设计,试验期12 d,第1天至第6天每头牛饲喂基础日粮+CLA 400 g·d-1,第7天至第12天恢复为饲喂基础日粮,每天记录产奶量及采食量,分析乳成分及乳脂肪球(MFG)粒径参数,对...