中草药添加剂对种公羊精液品质和耐冻性的影响

为探索中草药添加剂对种公羊精液品质的影响,用当归(Radix angelicae sinensis)、党参(Radix codonop sis)、黄芪(Radix astrag ali)、淫羊藿(Herba epimedii)、菟丝子(Semen cuscutae)等19味中草药复方配伍作饲料添加剂,按每头种公羊饲料量1%的比例饲喂3周,对种公羊的性反应和精液品质进行分析研究。结果表明:饲喂中草药添加剂后公羊性反应时间显著缩短;射精量、精子密度较对照显著和极显著提高;每次射精有效精子数达到61.64×109,比对照组增加2.36倍,差异极显著(P<0.01);精子头部畸形率较对照组降低8%(P<0.05);饲喂1周对精液质量有明显改善,饲喂3周至停药1周后可延缓精子质量下降的速度;且饲喂后种公羊的冻后精子活率和精子复苏率较对照和饲喂前显著提高(P<0.05),分别增加38.7%和28.9%。该复方中草药添加剂适用于高频度采精种公羊,可改善公羊的精液品质,提高人工授精过程中精液保存质量,有利于进一步发挥优良公羊的种用价值。     

Influence of methionine and dithioerythritol on sperm motility, lipid peroxidation and antioxidant capacities during liquid storage of ram semen

The aim of this study was to investigate the effects of methionine and dithioerythritol, added to the Tris extender, on ram sperm motility and LPO (lipid peroxidation) and antioxidant capacities during liquid storage up to 72 h at 5 °C. Ejaculates collected from five Merino rams, were evaluated and pooled at 37 °C. This study included two experiments. In experiment 1, each pooled ejaculate was divided into four equal aliquots and diluted (37 °C) with the base extender, containing 0 (control), 1, 2 and 4 mM methionine, at a final concentration of approximately 4 × 10⁸ sperms/ml (single step dilution), in a 15-ml plastic centrifuge tube. In experiment 2, dithioerythritol, at concentrations of 0 (control), 0.5, 1 and 2 mM, was used as an additive in the extender, and the procedure explained above was applied for the division of aliquots and the dilution of semen. Diluted semen samples were kept in glass tubes and cooled from 37 to 5 °C in a cold cabinet, and maintained at 5 °C. Sperm motility and LPO and total glutathione (GSH) and glutathione peroxidase (GPx) capacities were determined at 5 °C for periods of 0, 24, 48 and 72 h of liquid storage.The extender supplemented with 1 mM methionine led to higher motility percentages (77.0 ± 1.2%), in comparison to the control group (66.0 ± 4.9%), during 72 h of liquid storage (P < 0.05). As regards dithioerythritol, it did not statistically improve the motility rates for any of the storage times at 5 °C. In biochemical assays, differences in LPO levels between the groups with antioxidants and the control groups were not statistically significant. Compared to the control group, no significant difference was observed in GSH and GPx activities following the addition of methionine, during 72 h of storage. Total GSH and GPx activities did not increase significantly upon supplementation with 0.5 and 1 mM of dithioerythritol, compared to the control group, at any of the time points (P > 0.05). Dithioerythritol at 2 mM led (P < 0.01) to elevating GSH activity, compared to the control group, during 72 h of liquid storage. GPx activity was approximately 10 times higher for 2 mM of dithioerythritol (P < 0.001), compared to that of the control group at all time points.The question regarding the sustainability of sperm survival, LPO and antioxidant capacities following liquid storage of semen remains unanswered. Further studies are required for a better understanding of the biochemical changes and to obtain more information on the determination of lipid peroxidation and antioxidant capacities during cooled storage of ram semen.     

Scrapie resistance and production traits in Rambouillet rams: ram performance test 2002-2006

Sheep possessing alleles for the prion protein with glutamine (Q) or histidine, both reported as Q, at codon 171 are highly susceptible to scrapie. Incidence of scrapie infection is rare when animals possess at least one allele for arginine (R) at codon 171. The current USDA APHIS scrapie eradication program utilizes genotyping for alleles that confer resistance to scrapie. Although it has not been a criterion of registration, genotyping has been utilized in the University of Wyoming Ram Performance test since 2002. Performance test records from 2002 to 2006 (n=518) were analyzed to determine if any production loss or benefit was associated with scrapie resistance in rams. Performance of rams with scrapie resistant genotypes was equal to or better than scrapie susceptible rams. Based on test performance as an acceptable indicator of sire superiority, selection for rams with scrapie resistant genotypes should not negatively impact flock performance.     

Carcass characteristics of Awassi ram lambs slaughtered at different weights

Thirty Awassi ram lambs were used to study the effects of slaughter weight on carcass characteristics. Lambs were slaughtered at three different live weights (20, 30, and 40 kg). Empty body weight, hot and cold carcass weights and non-carcass components increased (P < 0.001) at a steady rate between all slaughter weights. Body length, leg length, maximum shoulder width, width behind shoulders and gigot width increased (P < 0.001) as slaughter weight increased from 20 to 40 kg. Linear dimensions measured on the surface of the M. Longissimus also increased (P < 0.001) with increasing slaughter weight. The ratio between width and depth of the longissimus muscle decreased (P < 0.01) at a steady rate between 20 and 40 kg indicating that the muscle increased more in depth than width. Dressing-out percentage was higher (P < 0.001) for lambs slaughtered at 30 kg live weight compared to other weights. Total lean and total bone decreased (P < 0.05) as a percent of cold carcass weight while total fat, subcutaneous and intermuscular fat percentages increased (P < 0.05) with increasing weight. Subcutaneous fat percentage was not affected by increasing body weight between 20 and 30 kg. Intermuscular fat percent was higher in all cuts except the leg where subcutaneous fat % was higher. Muscle to bone ratio increased (P < 0.001) while muscle to fat ratio decreased (P < 0.001) with increasing body weight in the four major cuts and the whole carcass. In conclusion, slaughtering Awassi ram lambs at weights up to 30 kg resulted in higher dressing-out percentage and better carcass characteristics than ram lambs slaughtered at heavier weights.     

切花菊"神马"花期调控的研究

研究了切花菊"神马"花期调控的基本方法和每个环节的关键技术措施.通过人为创造最佳环境,可以打破一年只开一次花的自然属性,按需开放,实现周年生产,为实现可观的经济收入和其他花卉生产提供参考.     

切花菊“神马”日光温室栽培技术研究

根据在大连地区的研究结果，提出切花菊“神马”目光温室栽培技术，主要包括定植准备、定植、摘心定干、张网、剥除侧蕾副芽、肥水管理、花期调控、B9处理、病虫害防治和采收上市等，供生产者参考。     

对塔什库尔干羊种公羊体重、体尺常规参数的研究

本文对塔什库尔干羊周岁和成年种公羊的体重、体尺指标的平均数（x）、标准差（s）、最小值、最大值进行了统计分析。结果表明,塔什库尔干羊周岁种公羊的平均体重（x）=（41．54±5．4：91）kg（n=1143）,最小值=35kg、最大值=75kg;塔什库尔干羊成年种公羊的平均体重（x）=（52．92±8．537）kg（n=393）、最小值=35kg、最大值=93kg。体重与体高、体长、胸围及管围呈正相关关系,差异极显著（P〈0．01）;其中体高与体长之间的正相关关系最大（r=0．661）,存在极显著差异（P〈0．01）。     

Reproductive response in suckling Corriedale ewes to the ram effect during the non-breeding season: Effect of postpartum condition and the use of medroxyprogesterone priming

The response to the ram effect and the use of progestagen priming was studied in postpartum suckling Corriedale ewes. Two experiments were carried out during the non-breeding season. In experiment 1, the effectiveness of the ram effect to induce fertile oestrus in postpartum ewes was determined. While no significant differences in the frequency of ewes in oestrus were found, the overall conception rate was significantly higher in ewes that were weaned at least 6 months before the study started (63.3%) than in 60–90 days postpartum ewes (45.3%, p < 0.01). In experiment 2, the influence of medroxyprogesterone acetate priming on the response to the ram effect in suckling Corriedale ewes was determined. The frequency of ewes in oestrus and conception rate between ewes that remained unprimed and 6-days-primed ewes were similar. We conclude that it is possible to induce oestrus in postpartum suckling Corriedale ewes using the ram effect during the non-breeding season and that the use of progestagen priming seems to be ineffective in improving the response of postpartum ewes to the ram effect.