Artificial Insemination with Frozen Semen in Ewes at Different Times of the Breeding Season

Totally 13575 ewes of two different breeds, Dala and Spel, were inseminated with semen, frozen in straws and thawed at 70°C for 8 sec. An insemination dose of 0.2 ml containing approx. 150 × 10⁶ spermatozoa with at least 45 to 50% progressive motility was imerted 5 to 12 mm into the cervix. The insemination was performed once between 12 and 30 h after the onset of heat. The NR rate of the Dala ewes increased significantly during the season. The NR rate of the ewes inseminated before 15. November was 44.3%, from 15. to 20. November 52.2%. from 20. to 25. November 55.3% and from 25. November and later 61.4%. The corresponding values for the ewes of the Spel breed were 57.3, 58.7, 61.5 and 71.0% respectively, and only the difference between the two last values was statistically significant. The difference between the fertility of the two breeds was significant within each of the periods .     

营养补偿初期苏尼特母羊对NDF、ADF消化能力的研究

将45只处于妊娠后期(90～150d)的苏尼特母羊随机分成4组,以不同的营养水平(代谢能:0.20、0.33、0.44、0.86MJ/kgW0.75·d)分组饲养,分娩后进行补偿生长试验,研究妊娠后期不同营养限制程度的母羊在补偿初期(分娩后0～6周)对中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)消化率的影响。结果表明:在补偿初期,各组母羊对ADF、NDF的消化率随着营养限制程度的增强而下降。     

现代集约化肉羊业主要关键技术研究与应用

专门化肉用种羊选定、引进后，通过适应性研究，在较大规模养羊业生产实践中。对现代集约化肉羊业的主要关键技术进行研究、完善和创新，组装集成并应用于生产。技术研究应用结果既为市场提供了大批专门化肉用种羊和优质安全的杂种肉羊，取得了高水平的研究成果及显著的经济效益和社会效益．又为我国目前正在迅速发展的集约化肉羊业提供了可靠的技术支持和理想的生产模式：从适宜的专门化肉羊品种到运用高效母羊快速扩繁技术．建立和完善有效的肉羊杂交利用体系，普遍应用种羊鲜、冻精生产大批肉用杂种羔羊，种植高产优质饲草及其科学加工调制和利用．建立严格兽医防疫制度．实行放牧 补饲或全舍饲的精细管理和集约化育肥，至生产优质、安全、标准肉羊，获得显著的经济效益和社会效益。     

日粮蛋白质水平对云南半细毛羊空怀母羊能量代谢的影响

为研究日粮蛋白质水平对云南半细毛羊空怀母羊能量代谢的影响,试验选择25只云南半细毛羊空怀母羊,平均分为5个组,分别饲喂蛋白质水平为8.4%、10.0%、12.3%、13.6%、15.9%的日粮,用全收粪法进行消化代谢试验,试验期共19 d,预试期14 d,正试期5 d。结果表明：（1）日粮蛋白质水平对总能摄入量无显著影响（P > 0.05）。（2）从组1到组5粪能逐渐下降,且组3、组4、组5较组1分别降低了10.5%、11.4%、13.7%（P < 0.05）,组5较组2降低了9.5%（P < 0.05）。（3）从组1到组5尿能逐渐增加,除组2与组1、组3间差异不显著（P > 0.05）外,其余组间差异极显著（P < 0.01）。（4）组4和组5总能消化率较组1极显著提高13.2%和11.8%（P < 0.01）,其余各组差异不显著（P > 0.05）。组4总能代谢率较组1极显著提高9.8%（P < 0.01）,其余各组差异不显著（P > 0.05）。对于消化能代谢率,组1和组2差异不显著（P > 0.05）,组3、组4和组5依次显著降低（P < 0.05）。（5）蛋白质采食量与总能消化率、消化能代谢率间的回归方程分别为：Y=0.917X+45.872（R2=0.853）|Y=-0.370X+87.735（R2=0.899）。综上,日粮蛋白质水平与粪能呈负相关,与尿能呈正相关。日粮蛋白质水平为13.6%时,总能消化率和总能代谢率均较8.4%蛋白质水平组极显著提高。总能消化率随蛋白质采食量的提高而线性升高,消化能代谢率则随蛋白质采食量的提高而线性降低。 [关键词] 蛋白质|云南半细毛羊|空怀期|能量代谢     

The hypocalcemic response to protamine as a measure of bone resorption

The heparin antagonist protamine inhibits bone resorption. In the present study protamine was given i.v. at a dose of 10 mg/kg to goats and sheep in various stages of pregnancy and lactation. It is known that bone resorption increases as pregnancy progresses. In sheep maximum in bone resportion is reached at early lactation. The hypocalcemic response to protamine followed a similar course. The slightest decrease in serum calcium was obtained during early pregnancy and the greatest during late pregnancy and early lactation. Protamine increased serum inorganic phosphorus. The increase was most pronounced during early pregnancy. Protamine did not significantly change serum magnesium.Five lactating ewes were given 25000 i.u./kg of vitamin D3. Serum calcium increased and the hypocalcemic response to protamine was greater after vitamin D₃ administration than before.The results showed that the hypocalcemic response to protamine can be used as an indicator of the role of bone resorption in calcium homeostasis in various physiological situations.     

哈萨克母羊分娩前与胎儿组织器官细菌的多样性

【目的】研究分娩前哈萨克母羊和胎儿组织、肠道内容物及相关器官菌群的多样性。【方法】试验选择5只4岁、胎次相同、健康的妊娠后期母羊,平均体重为(55.64±4.37) kg,安乐死后,分离各组织器官并采集相关样品,用于分析菌群多样性。【结果】(1)母羊唾液、小肠内容物及羊水中有较高的多样性,chao1指数分别为1 042.02、1 058.31、1 011.22,ACE指数分别为1 069.18、1 067.41、1 014.17。(2)在物种分类水平上,母羊小肠、盲肠内容物、脐带及羔羊胎粪中厚壁菌门丰度较高,占比分别为79.08%、65.94%、49.66%和35.69%;在母羊唾液和羔羊瘤胃中拟杆菌门占比较高,分别为26.98和51.80%;羔羊瘤胃和母羊唾液中变形菌门的占比分别为64.92%和41.92%。(3)羔羊瘤胃液、胎粪及脐带中物种相似性较高,母羊唾液和瘤胃液中物种相似性较高,母羊小肠内容物和母羊盲肠内容物中物种相似性较高。【结论】母羊妊娠后期唾液、小肠内容物及羊水中有较高的多样性指数,厚壁菌门、变形菌门及拟杆菌门是此阶段母羊和胎儿各组织器官主要的物种。     

Fluctuations of serum cortisol,insulin and non-esterified fatty acid concentrations in growing ewes over the year

Background

The physiological levels of endocrine and metabolic parameters in Slovene autochthonous breeds of sheep are not yet well known, nor are the mechanisms of their adaptability and responses to climate and environmental factors.Therefore, the aim of this study was to evaluate fluctuations of cortisol, insulin and non-esterified fatty acids (NEFA) in growing ewes over an one-year period. Blood samples were collected monthly from 10 yearling Jezersko-Solchava, 10 Bovec and 10 Istrian ewes. Serum cortisol, insulin and NEFA were measured with commercial kits.

Results

Mean monthly cortisol values fluctuated with low levels in summer and high levels in autumn. Significant peaked cortisol values of 25.69 ± 6.89, 14.67 ± 2.43 and 21.11 ± 7.25 μg/L in Jezersko-Solchava, Bovec and Istrian breed, respectively, were found in September (Bovec breed) and October (Jezersko-Solchava and Istrian breed). Mean monthly insulin values increased during the observation period. The highest levels of 14.60 ± 3.15, 16.03 ± 5.35 and 12.56 ± 2.52 μIU/mL in Jezersko-Solchava, Bovec and Istrian breed, respectively, were observed in the last sample collection in May. NEFA concentrations were found to be low except in some autumn and spring months. The peak values were observed in March for Jezersko-Solchava and Istrian breed (0.60 ± 0.05 and 0.66 ± 0.10 mmol/L), and in April for Bovec breed (0.71 ± 0.11 mmol/L).

Conclusions

Monthly fluctuations of cortisol, insulin and NEFA were measured in all observed sheep breeds, but between-breed differences in monthly values of examined parameters were insignificant. Significantly increased serum cortisol levels were found in autumn for all breeds and were probably associated with the onset of puberty and low environmental temperature. A gradual increase of insulin level in the examined ewes was in parallel with their growth. Significantly higher NEFA values in spring suggest qualitatively insufficient feed supply during that period.     

Effect of short‐term supplementation with rumen‐protected fat during the late luteal phase on reproduction and metabolism of ewes

This study was designed to study the effect of short‐term supplementation with rumen‐protected fat during the late luteal phase on reproduction and metabolism of sheep during breeding season. Seventy‐six ewes (Rahmani, Barki and Awassi × Barki) were allocated to two groups considering genotype: the control ewes (C‐group) received a maintenance diet, and the fat‐supplemented ewes (F‐group) received the maintenance diet plus 50 g/head/day of rumen‐ protected fat (Megalac) for 9 days during which oestrus was synchronized. The latter had been accomplished using double intramuscular injection of prostaglandin F_2α (PGF_2α) 11 days apart. Ovarian activity, serum concentration of cholesterol, glucose, insulin and reproductive performance variables were recorded. Data were analysed considering treatment (group) and genotype. Supplementation had positive effects on the overall mean serum concentrations of cholesterol (p < 0.05), glucose (p < 0.05) on day 6 of nutritional treatment and insulin (p = 0.07) on day 8. Fat supplementation did not affect the total number of follicles, follicle populations and ovulation rate. However, fat‐supplemented Rahmani ewes tended to have higher ovulation rate compared with other breeds (treatment × breed interaction, p = 0.06). Treatment also did not affect the mean concentration of serum estradiol or progesterone. Supplemented ewes had higher conception (p = 0.06) and lambing rates (p < 0.05) compared with control. In conclusion, short‐term supplementation with rumen‐protected fat as a source of energy around breeding time improved metabolism, conception and lambing rates of ewes without effects on steroidogenic capacity and ovarian activity being apparent.     

苏尼特羊肉食用品质的研究

本研究以不同月龄苏尼特羊为对象,取4个部位肌肉,测定其品质指标,并以小尾寒羊肉对照,结果表明:品种因素对肌肉的剪切值、熟肉率、失水率、蛋白质含量、肌纤维直径、密度的影响显著,其差异显著(p<0.001)但对色泽、胆固醇含量、无显著影响.年龄因素对苏尼特羊肌肉的剪切值、色泽A值(红度)、熟肉率、失水率、蛋白质含量、胆固醇含量、肌纤维直径、密度有显著的影响(p<0.001).部位因素对剪切值;色泽L值和a值、失水率、熟肉率、蛋白质含量、肌纤维直径、密度的影响显著(p<0.001).试验证明苏尼特羊肉的色泽、保水性能、蛋白质含量、熟肉率、组织学特性均优于小尾寒羊.     

苏尼特绵羊肉理化品质的分析研究

苏尼特绵羊是内蒙古优良地方肉羊品种之一,以肉质嫩、口感好而名扬全国。以苏尼特绵羊和小尾寒羊背最长肌为原料肉,进行比较研究。结果表明,相对于小尾寒羊,苏尼特绵羊肉不仅具有高蛋白、低脂肪和低胆固醇等很高的营养品质,而且具有保水性好、嫩度高、熟肉率高等优良食用品质。对羊肉颜色的研究结果表明,与小尾寒羊相比,苏尼特绵羊肉的肉色更鲜红饱满。这些结果充分说明了苏尼特绵羊肉具有理想的化学成分和物理性状,也为苏尼特绵羊肉品质优良的主观印象提供了客观实验依据。