“青大1号”紫花苜蓿叶蛋白提取条件优化

为了开发新的食用蛋白质资源,本试验以“青大1号”紫花苜蓿新品系青干草为原料,采用酸化加热法配合加盐法提取叶蛋白.单因素试验设计,分别考察料水比、加盐量、絮凝时间、pH、预浸时间、絮凝温度6个因素对粗蛋白质提取率的影响,并以单因素试验结果为依据,采用四因素（料水比、加盐量、絮凝时间、pH）三水平L9（34）正交试验设计进行提取工艺优化.试验结果表明：影响粗蛋白质提取率的因素,从大到小依次为料液比、絮凝时间、pH、加盐量.当絮凝温度为70℃、料液比为1∶10、加盐量1％、絮凝时间5min、pH为4时是叶蛋白提取的最优提取条件.     

植物生长调节剂、基质对三个品种费约果扦插生根的影响

选取五年生健壮费约果树为母株,采用L9(33)正交设计法研究植物生长调节剂、基质对三个品种费约果半木质化枝条扦插生根的影响。本试验结果表明：不同品种、植物生长调节剂和基质处理的生根的影响呈显著性水平。影响费约果扦插枝条生根率因素的主次顺序为品种>植物生长调节剂>基质;影响根长因素的主次顺序为基质>植物生长调节剂>品种;影响插穗根数的因素主次顺序品种>基质>植物生长调节剂。Gemini品种经1000 mg/L ABT浸泡两分钟,以腐叶土+珍珠岩为基质,生根效果最好,生根率为70.00%,平均根长为8.85 cm,平均根数为10.22条/穗;Unique品种经1000 mg/L ABT浸泡两分钟,以腐叶土+蛭石为基质,生根效果较好,生根率为56.67%,平均根长为9.32 cm,平均根数为12.33条/穗;Coolidge品种生根率低,均≤20 %。     

三种草坪草净光合速率和蒸腾速率的日变化特点研究

研究了在晴天的条件下，假俭草、细叶结缕草和地毯草净光合速率和蒸腾整编的日变化特点。结果表明：（1）假俭草和细叶绍缕草的净光合速率的日变化曲线均为双峰型，而地毯草为三峰型，3种草出现峰值的时间不同，均有明显的“午睡”现象，日平均净光全速率的大小顺序为俭草＞地毯草＞细叶结缕草；（2）假俭草和细叶结缕草的蒸腾速率的日变化曲线均为双峰型,而地毯草为单峰型，3种草出现峰值的时间有所判差别，“午睡”现象均不明显，日平均蒸腾速率的大小顺序为细叶绍缕草＞地毯草＞假俭草；（3）不同生态因子与3种草坪草净光合速率、蒸腾速率的相关程度均不相等。同种态因子与不同草坪草的净光合速率、蒸腾速率的相关程度也不一样。     

控制性隔沟交替灌溉条件下土壤蒸发的预测研究

棵间土壤蒸发是控制性交替灌溉条件下农田土壤耗水的重要组成部分,为了了解沈阳地区潮棕壤土条件下大豆田不同控制性交替灌溉制度下的土壤蒸发变化规律,对土壤蒸发进行预报,采用Micro-lysimeters(MLS)对不同灌溉处理下的土壤蒸发量进行了测定,并建立了以气象因子、土壤含水率和叶面积指数为自变量的土壤蒸发的预报模型.结果表明,在本试验的条件下,各处理的相对土壤蒸发率(E/ET0)与表层土壤含水率(θ)的关系均呈指数函数形式,决定系数在0.71以上.各处理的E/ET0与LAI之间亦呈很好的指数函数关系,决定系数均在0.78以上.     

Selection for ovulation rate in rabbits

An experiment of selection for ovulation rate was carried out. Animals were derived from a synthetic line first selected 12 generations for litter size, then 10 generations for uterine capacity. Selection was relaxed for 6 generations. Selection was based on the phenotypic value of ovulation rate with a selection pressure on does of 30%. Males were selected from litters of does with the highest ovulation rate. Males were selected within sire families in order to reduce inbreeding. Ovulation rate was measured in the second gestation by a laparoscopy, 12 days after mating. Each generation had about 80 females and 20 males. Results of three generations of selection were analyzed using Bayesian methods. Marginal posterior distributions of all unknowns were estimated by Gibbs sampling. Heritabilities of ovulation rate (OR), number of implanted embryos (IE), litter size (LS), embryo survival (ES), fetal survival (FS), and prenatal survival (PS) were 0.44, 0.32, 0.11, 0.26, 0.35, and 0.14, respectively. Genetic correlation between OR and LS was 0.56, indicating that selection for ovulation rate can augment litter size. Response to selection for OR was 1.80 ova. Correlated responses in IE and LS were 1.44 and 0.49, respectively. Selection for ovulation rate may be an alternative to improve litter size.     

Reproductive and productivity traits of goats grazing Acacia cyanophylla Lindl. with and without daily PEG supplementation

A grazing experiment, conducted for 90 days compared the effect of polyethylene glycol (PEG) supplementation on postpartum reproductive traits and productivity of suckling goats grazing Acacia cyanophylla Lindl. A total of 54 native adult goats (34.4 ± 5.49 kg) were randomly allocated, 24 h after kidding, to 2 treatment groups balanced for age and the number of reared kids. Goats in both treatment groups designed C and PEG grazed in acacia for approximately 5 h every day and received each on daily basis 0.3 and 0.4 kg of hay and concentrate respectively. In addition, goats in treatment PEG were initially supplemented with 10 g/day of PEG and this supplement was then increased to 20 g /goat/day over the last 60 days of the trial. Goats receiving PEG tended (P > 0.05) to spend more time browsing acacia than those in treatment C. There were no treatment effects on live weight change of the goats, growth of their kids until 90 days of age or composition of their milk in terms of fat, protein and urea contents. Similar proportions of 74.1 and 77.8% of goats resumed postpartum ovulation with a mean ovulation rate of 1.50 ± 0.61 and 1.67 ± 0.47 (P > 0.05) in respectively the PEG and C treatments. PEG supplementation was associated with an increase (P < 0.05) in ovulation rate at the second postpartum ovulation occurring approximately 27 days after the application of the nutritional treatments (1.76 ± 0.60 versus 1.25 ± 0.45); 9 of the 13 goats ovulating in the PEG treatment were bearing more than one corpus lutuem in comparison to only 3 out of 12 females in the C group (P < 0.05). The likely increased availability of proteins in the PEG receiving goats could explain their higher ovulation rate.     

"雅士勇"口服液对猪的射精量和精子畸形率的影响

以大白猪和长白猪为研究材料,对照组不饲喂"雅士勇"口服液,两试验组分别饲喂25 mL和30 mL"雅士勇"口服液,研究"雅士勇"口服液对猪的射精量和精子畸形率的影响。结果表明,"雅士勇"口服液对射精量无明显影响(P>0.05),但对种公猪的精子畸形率有显著影响,对照组的精子畸形率均极显著地高于两个试验组(P<0.01),而两试验组之间精子畸形率差异不显著(P>0.05)。     

高原地区肉鸡能量、氮和氨基酸代谢率测定及其方法的研究

采用经典全收粪代谢试验方法和Sibald强饲快速法，在青海省西宁地区测定了爱拔益加肉仔鸡的能量、氮和氨基酸代谢率，并对肉用公鸡和蛋用公鸡的代谢率进行了比较。结果表明，高原地区肉用公鸡生长期（29-60日龄）的能量、氮和氨基酸代谢率随日龄的增加而降低；日粮能量、蛋白水平对其能量代谢率无影响，对氮和氨基酸代谢率有影响。35-38日龄和57-60日龄期间，肉用公鸡的能量代放率和总氨基酸代谢率显著低于蛋用公鸡；4-5月龄肉用公鸡的表观能量代谢率显著低于蛋用公鸡。未去盲肠公鸡对豆粕、肉骨粉、脱毒菜籽饼的氨基酸表观和真代谢率高于去盲肠鸡；公鸡去盲肠后对低纤维素日粮中的消化率影响较大；内源物矫正对鸡代谢试验测定结果具有可靠性和精确性。用体外胃蛋白酶法测定的三种蛋白质饲料的氨基酸代谢率与体内法具有较好的回归关系。     

Examining the evidence for ecologically sustainable ostrich breeding practices on natural veld in the Little Karoo,South Africa

Land degradation in the Little Karoo is extensive. Overstocking of breeding ostriches on natural veld has been among the main causes of this. The National Department of Agriculture has set a general stocking rate of 60 ha LSU^?1 as a guideline for livestock on natural veld in the Little Karoo, which equates to 22.8 ha ostrich^?1. The aim of this review is to examine the scientific principles, data and assumptions the current recommended stocking rate for breeding ostriches on natural veld in the Little Karoo is based on and to investigate if there is a stocking rate (or range of stocking rates) that has been demonstrated to be ecologically and/or economically sustainable. We found no evidence that the recommended stocking rate of 22.8 ha ostrich^?1 is economically or ecologically sustainable in the Little Karoo. Most studies only addressed a single dimension of sustainability, and stocking rates deemed to be economically sustainable were several times higher than ecologically based recommendations. Given that economic and ecological objectives appear irreconcilable on open veld, an industry switch from extensive to intensive breeding practices may be a solution. Further research is required that integrates the socio-economic and ecological aspects of ostrich farming in the Little Karoo.