西北寒旱地区湖羊及其杂交后代生长发育模型分析

本试验测定了舍饲条件下的215只湖羊和60只湖杜湖[湖羊♂×(杜泊羊♂×湖羊♀)♀]杂交羔羊0~12月龄的体重,采用Gompertz模型和Logistic模型拟合了湖羊和湖杜湖杂交羔羊0~12月龄生长过程,并分析比较了生长参数及模型估计值,进而评价湖杜湖的杂交优势。结果表明,2种模型的拟合度(R²)均在0.96以上,拟合效果好,其中Gompertz模型拟合两个种群效果好于Logistic模型;湖羊公、母羔拐点月龄分别为2.55和1.73个月,拐点体重分别为17.00和13.14 kg;湖杜湖公、母羔拐点月龄均早于湖羊,公、母羔拐点体重分别相差0.74和2.66 kg,公、母羔累积生长均极显著高于湖羊(P<0.01)。结果说明湖杜湖早期生长强于湖羊,湖杜湖杂交效果显著。     

Pyogranulomatous lesion causing neurological signs localised to the sacral region in a horse

This case report describes neurological signs associated with a pyogranulomatous lesion within the sacral vertebral canal of a horse. The clinical findings included urinary overflow incontinence and reduced anal, perianal and tail tone. The horse failed to respond to medical management and a guarded prognosis for return to athletic performance initiated the decision for euthanasia.     

人工模拟飞播牧草对治理“黑土滩”型退化草地的效果调查

采用路线定点抽样方法 ,对人工模拟飞播治理“黑土滩”进行了调查 ,结果表明 ,飞播后平均每公顷鲜草产量 991 2 .6kg,比播前提高了 1 1 .5 5倍 ;植被盖度达 70 %～ 80 % ;草群结构改变 ,一些已消失了的优良牧草相继出现 ,不食毒杂草大幅度下降 ,治理效果良好。     

Subtropical goats ovulate in response to the male effect after a prolonged treatment of artificial long days to stimulate their milk yield

The objectives of this study were to determine (i) if in subtropical goats that gave birth during mid‐December, the exposition to an artificial long‐day photoperiod consisting in only 14 hr of light per day can increase the milk yield and (ii) to test whether these females can respond to the male effect at the end of the prolonged photoperiodic treatment. In experiment 1, 17 lactating goats were maintained under natural short days (control group), while another 22 goats were maintained under artificial long days (treated group) consisting in 14 hr light and 10 hr darkness starting at day 10 of lactation. The continuous exposition to an artificial long‐day photoperiod produced an increase in the milk yield level during the first 110 days of lactation (time × treatment interaction; p = .01), while none of the milk components were modified due to the photoperiodic treatment (p > .05). In experiment 2, all control and treated anovulatory goats were submitted to the male effect using photostimulated males. All females showed oestrous behaviour within the first 10 days that were in contact with males (100% in both groups; p > .05). Thus, the latency to onset of oestrus did not differ between females from control (58.2 ± 3.0 hr) and treated (62 ± 4.6 hr) groups. Male exposition provoked ovulation independently if females were previously under long days or natural photoperiod (96 vs 100%, respectively; p = .79). It was concluded that exposure to 14 hr of light per day in subtropical goats that gave birth in late autumn stimulates milk yield without preventing the ovulation in response to the male effect at the end of the prolonged photoperiodic treatment.     

西北寒旱地区舍饲湖羊生长发育特征研究

湖羊是世界上稀有的绵羊地方品种,以多胎、早熟、早期生长发育快、宜舍饲等优良性能而著名。为系统了解湖羊生长发育的基本规律,更好地开发利用湖羊这一优良地方品种资源,本研究以3,6,12和24月龄湖羊公羊为对象,每个时间点随机选择6只,共24只,测定其体重、组织器官及消化道各个部分重量、肠道长度及肉品质相关参数。结果表明,3~6月龄湖羊生长速率最快,6月龄之后逐渐降低;3~6月龄之间心、肝、脾、肺、肾、头蹄和皮的增长强度随着日龄的增大而增长,除头、蹄、皮外,其他内脏器官的生长强度逐渐降低,12月龄之后趋于稳定;头、蹄、皮的生长在6月龄之后趋于稳定,仍然保持较高的生长强度;瘤胃的生长强度始终大于体重生长强度,小肠的生长始终小于体重,而除直肠外,大肠的生长强度与体重相近。6月龄湖羊公羔与12月龄相比屠宰率、眼肌面积无显著差异,而6月龄湖羊公羔背膘厚极显著增高,随着年龄的增长肉色逐渐变暗。综合以上各项指标认为,本试验条件下,6月龄为肥羔生产最佳屠宰日龄。     

增产菌对高寒地区燕麦产草量的增产效应

采用增产菌拌种,喷施２种方法的二因素随机区组设计,对燕麦草的增产效应进行了研究,研究结果,增产菌对燕麦的增产效果显著（Ｐ〈０．０１）,最佳拌种量３００ｇ／ｈｍ＾２,最佳喷施量为３００ｋｇ／ｈｍ＾２拌种和喷施增产菌对燕麦的增产效果是相互独立的,拌种与喷施的交互作用不显著（Ｐ〉０．０５）,两者的增产效应是可加效应,最佳处理组合为３００ｇ／ｈｍ＾２拌种量＋３００ｇ／ｈｍ＾２喷施量。