金华猪繁殖性状的统计学分析

采用金华猪场1979～1999年金华猪的繁殖性能生产记录,测定了2355头金华母猪(纯繁)和金华猪(K)与约克夏(Y)、长白(L)、杜洛克(D)、汉普夏(H)杂交后代的繁殖性状。综合考虑各性状的各种固定效应,并建立各性状的固定效应模型,对其进行方差分析,计算各性状的最小二乘均数(LSM),对影响较大的固定效应在各观察水平上的LSM进行分析与比较。固定效应分析结果表明:品种、胎次、季节、年份对产活仔数、60日龄头数的影响极显著(P<0.01)。而产仔数受胎次、季节、年份的影响极显著(P<0.01)。金华猪纯繁组以及LK×D、K×L杂交组的产仔数、产活仔数较高,K×L、K×Y杂交组合的60日龄头数较高。而其他外来品种之间杂交组合的繁殖性状显著低(P<0.01)。说明金华猪具有高产的优良特性。金华猪产仔数、产活仔数随胎次逐渐递增,6～7胎达到高峰。金华猪夏季产仔数最高为15.72±1.66,显著高于秋、春、冬(P<0.01)。产活仔数春、夏、秋季无差异(P>0.05),但高于冬季(P<0.05)。1982～1987年间金华猪无论是产仔数还是产活仔数整体都维持较高的水平。     

Epidemiology and diagnosis of subclinical iodine deficiency in crossbred cattle of Punjab.

OBJECTIVE: To determine the prevalence of iodine deficiency in crossbred cows (taurus x indicus) of Punjab and to assess the diagnostic value of the plasma concentrations of thyroid hormones, total cholesterol and free fatty acids in iodine deficiency. The efficacy of ethiodised oil, as a long-term supplement of iodine, was also evaluated. PROCEDURES: Base-line survey of iodine status was conducted by measuring plasma inorganic iodine (PII) concentration in 48 crossbred cows from 31 dairy units. Concentrations of plasma triiodothyronine (T3), thyroxine (T4), total cholesterol and free fatty acids were compared between iodine deficient and normal cows. Circulating T4 and T3 concentrations were also determined before and after injection of ethiodised oil in cows with low PII levels. RESULTS: The mean prevalence of iodine deficiency was 35.9% and showed considerable geographical variation from 0 to 86% within Punjab. Cardinal clinical signs of iodine deficiency were absent and basal plasma T3 and T4 concentrations and their ratio did not differ between deficient and control cows. Activity of circulating T4 and T4:T3 ratio increased in response to ethiodised oil injection and persisted beyond 70 days after injection. CONCLUSION: Asymptomatic iodine deficiency is prevalent in crossbred cows of Punjab and response to iodine supplementation is the most reliable index of thyroid dysfunction associated with iodine deprivation. The results of this study also support the view that injection of 1 mL of 78% ethiodised oil can prevent iodine deficiency for more than 70 days.     

蛋鸡杂种胚胎生活力及其杂交遗传力的研究

在利用京白快羽母鸡对１７０只罗曼Ｄ系公鸡的快慢羽基因位点进行测交试验的过程中，收集了杂种后代孵化期胚胎生活力的数据用于本研究，结果表明：（１）孵化后期（１３－２１天）平均每天的胚胎死亡率约为前中期的两倍，孵化前期（１－６天）的死亡率略高于中期，孵化中期（７－１２天）的死亡率最低；（２）罗曼Ｄ系纯合慢羽公鸡杂交后代的生活力与杂合公鸡后代相比没有显著的差异，据此可以假设：快慢羽基因与胚胎生活力性状间无相关关系；（３）用ＨｅｎｄｅｒｓｏｎⅢ估计的胚胎生活力性状的杂种遗传力在０．００６到０．０５４之间，ＲＥＭＬ方法的估计值在０．００１到０．０４７之间。用ＨｅｎｄｅｎｏｎⅢ估计的遗传力一般均高于ＲＥＭＬ方法的估计值。     

In-House Composting of Layer Manure in a High-Rise,Tunnel-Ventilated Commercial Layer House During an Egg Production Cycle

In-house composting has the potential to improve the viability of the high-rise house for commercial egg production by producing a value-added product from the manure without requiring a separate composting facility. The feasibility of in-house composting depends in part on having the ability to handle the manure mass that accumulates over an extended period. This field study showed that in-house composting is possible for the length of an egg production cycle. Beginning with windrows of a carbon source, fresh pine sawdust or shredded yard waste, upon which manure fell from the cage rows above, compost volume grew rapidly in the first few weeks, but slowed after composting activity peaked, as indicated by compost temperatures. In cold weather, when ventilation rates were low, compost remixing temporarily produced high ammonia levels in the house, but ammonia levels at other times were comparable to or lower than those in an undisturbed house. The final compost was friable and nutrient-rich, although the handling quality of the yard waste compost was reduced by persistence of elongated woody pieces of the original carbon source. The ability to access the manure storage area of a high-rise house over a cycle of production gives potential to deliver manure amendments to improve nitrogen retention in the compost, which would have the effect of improving its fertilizer value and reducing ammonia emission from the house.     

饲料原料与瘤胃培养残渣(8、12、16小时)氨基酸组成差异的研究

选用3头装有瘤胃瘘管的改良阉牛 ,利用尼龙袋技术对不同饲料降解后残渣的氨基酸(AA)组成与原料AA组成的差异进行了研究。结果表明 ,与精料氨基酸浓度相比在降解后有上升趋势(P<0.05)的氨基酸有Ala、Phe、Val、Ile和Leu(其中后3种氨基酸为支链氨基酸) ;在降解后有下降趋势(P<0.05)的氨基酸有Gly、Arg、Tys、Lys、Met和Cys。各氨基酸降解前后的浓度存在强相关回归关系。     

贵州省天然林保护工程区人工商品林采伐试点成效及问题探讨

人工商品林的合理采伐是实现森林的社会、经济、生态三大效益,缓解木材供需矛盾的有效手段,也是合理经营森林的重要途径。本文阐述了贵州省2003—2004年天保工程区人工商品林采伐试点的必要性和实施情况,总结了采伐试点取得的成效,对采伐实施中存在的问题进行了分析探讨并提出了建议。     

Incentives for Participation by Local Communities in the Establishment of Commercial Plantations in Sichuan Province, China

The 1998 floods in China triggered the implementation of the Natural Forest Conservation Program (NFCP) which includes: (i) a logging ban over state-owned natural forests in order to protect the deteriorating natural environment, and (ii) strategies for the establishment of commercial plantations and relocation of laid-off forest workers, with the aim of mitigating the negative socioeconomic impacts of the logging ban. In this paper, Sichuan province is used as a case study to analyze the disincentives faced by local communities in developing commercial plantations and the institutional failure to address the disincentive issue. Insight on the necessity of 'real participation' of local communities has been provided, and ways to create incentives as well as institutional rearrangement has been explored and recommended.     

德西黄三元杂交幼牛产肉性能研究

本文对甘肃省武威市凉州区新华乡的6头德西黄三元杂交牛11-12月龄育肥牛的产肉性能进行测定。其结果：育肥期末体重、日增重、屠宰率、净肉率、胴体产肉率、肉骨比、眼肌面积分别是322.67kg、1101.85g、55.33%、45.09％、81.47％、5.09、75.9cm^2。表明该三元杂交组合的肉用性能良好，比二元杂交的西黄有明显提高。     

商品林分类指标体系的研究

在综合分析影响商品林经营的社会、经济、自然、生态、法律等因子基础上 ,提出商品林分类标准和指标体系 ,并以山西管涔林业局杜家村林场为例 ,验证商品林分类指标 ,为商品林建设提供依据     

早期断奶对母猪繁殖性能影响的研究

按母猪泌乳期(28天、35天和45天)设3组,选二花脸经产母猪20头,大约克经产母猪35头,断奶至发情、配种和下次繁殖的繁殖周期:二花脸母猪Ⅰ组分别为5.75天、8天和149.25天,Ⅱ组分别为5.1天、7.3天和156.5天,Ⅲ组分别为4.9天,7.0天和166天;大约克母猪Ⅰ组分别为5.2天、7.2天和149.2天,Ⅱ组分别为4.7天、6.7天和156.2天,Ⅲ组分别为4.2天、6.2和165.5天。各品种各组合的情期受胎率均为100％;同品种内各断奶日龄组间的产仔数、产活仔数和初生窝重均无明显差异(P>0.05)。