动物生长模型研究进展(综述)

本文综述了动物生长方程的研究历史和现状,并对动物生长模拟模型的形成和发展以及近十年来的研究概况进行了总结,同时对生长模拟模型的各个组成部分进行了详细的分析和讨论。     

正反交对猪睾丸及附睾发育影响的研究

巴克夏、雅南、巴克夏×雅南、雅南×巴克夏、杜洛克×雅南等品种组合仔公猪197头,从初生至90日龄,分七个阶段,采取睾丸及附睾制切片,分别测曲精细管直径及附睾各部位宽度;观察长核精子出现日龄,经统计分析比较结果;曲精细管直径及附睾管宽度为较高遗传力性状,不表现明显的杂种优势;睾丸及附睾的生长发育有一定的母体效应存在。雅南仔公猪睾丸发现长核精细胞在55日龄,巴雅、杜雅约80日龄,而巴克夏、雅巴则直至90日龄尚未见出现。     

“非典”过后看特种养殖业

介绍了“非典”与动物的关系及对特种经济动物饲养业的影响 ,并对首批解禁的 5 4种动物的市场进行了预测     

The economic implications of bush encroachment on livestock farming in rangelands of Uganda

The objective of this study was to assess the economic implications of shrub encroachment on pastoral rangeland productivity in Mbarara district, in south western Uganda. Sixty pastoral households were surveyed, thirty of which were grazing on cleared farms (with less than 25% of grazing covered by bush) and thirty were grazing on bushy farms (with more than 75% of grazing land covered by bush). The study was a survey and did not involve rigorous experimental work. Results indicated that cleared farms had higher herbage dry matter yield ranging from 1 850 kg ha^?1 to 2 230 kg ha^?1, compared to a range of 622 kg ha^?1 to 1 190 kg ha^?1 on bushy farms. Heifers on cleared farms reached puberty earlier and calved relatively earlier (12-30 months) as opposed to 24-36 months on bushy farms. The mean calving rate on cleared farms was higher (33.6%) than 22.6% on bushy farms. Mean milk yield on cleared farms was 3.8 L cow^?1 d^?1 compared to 2.4 L cow^?1 d^?1 on bushy farms. Results of body condition score indicated that cattle on cleared range had a higher mean score of 5.8 compared to 4.2 on bushy farms. Mean annual gross income was US$49.393 per cow per annum on cleared farms compared to US$23.351 on bushy farms. Financial efficiency measured by TR/TVC ratio was 1.2 on cleared farms compared to 1.1 on bushy farms. From the findings of the study, it was concluded that shrub encroachment led to reduced herbage DM yield and low levels of crude protein of the pasture, while clearing more than doubled herbage DM production. As a result, animal productivity in terms of milk yield, body condition and reproductive performance were also reduced. Cleared farms were more profitable than bushy ones in terms of gross margins due to higher animal performance and hence higher incomes. The financial efficiency of cleared farms was low due to high costs of shrub control. Shrub encroachment is a serious problem facing pastoral production in Mbarara district and requires adequate attention.     

复方泰乐菌素注射液的药代动力学研究

以反相高效液相色谱法为定量手段,研究复方泰乐菌素（商品名为泰乐松）给鸡单剂量用药后的药动学规律。血药由甲醇－氯仿混合液提取,采用ＯＤＳ柱,以甲醇－乙腈－醋酸钠溶液为流动相,可变波长检测,复方泰乐菌素三组分主要的药动学参数为：氯霉素：Ｔ１／２Ｋ＝２０．７９±１．００４ｈＴｍａｘ＝１．３１６±０．２４１ｈＣｍａｘ＝１２．４９±０．７３５μｇ／ｍＬＡＵＣ＝３９１．３５２±５．０３６μｇ／（ｍＬ·ｈ）泰乐菌素：Ｔ１／２Ｋ＝９．９５３±４．３０６ｈＴｍａｘ＝１．８９５±０．９５１ｈＣｍａｘ＝１．６１４±０．２０２μｇ／ｍＬＡＵＣ＝２６．２８２±６．０３３μｇ／（ｍＬ·ｈ）泼尼松：Ｔ１／２Ｋ＝１．６２７±０．２０２ｈＴｍａｘ＝１．６７５±０．０９６ｈＣｍａｘ＝０．２６１±０．０８５μｇ／ｍＬＡＵＣ＝１．２５３±０．３３μｇ／（ｍＬ·ｈ）     

动物原虫病药物防治要略

原虫病给我国养殖业带来了巨大的经济损失,人畜共患原虫病也对我国公共卫生造成了很大的威胁,正确的用药对防治原虫病具有很重要的作用。结合长期的临床实践和有关文献,对目前动物常见原虫病的治疗和预防药物进行了综述,以期为临床治疗用药提供参考。     

不同添加物对生长肥育猪的效果研究

本文研究了不同添加物对40—90kg长白×成华杂交猪生产成绩的影响。结果表明,在饲粮DE13.8MJ/kg,CP13—14％条件下,同时添加0.34％赖氨酸、125ppmCu和250ppm复合抗生素时的生长成绩比单独添加好,全期平均日增重(ADG)为817克,饲料转化率(F/G)为3.23;而经济效益则以只添加125ppmCu时为最高;高氯酸盐(ClO_4~-)与抗生素或赖氨酸合用可进一步改进生产成绩;对生长肥育猪生产成绩的改善,Cu的效果比抗生素好。     

Effect of long-term exclusion of fire and herbivory on the soils and vegetation of sour grassland

The effect of long-term exclusion of fire and herbivory, as mediated by aspect, on soils and the structure, composition, and diversity of vegetation was investigated in Döhne Sourveld (34 years), Piet-Retief Sourveld (45 years) and Southern Tall Grassveld (49 years). Exclusion had no effect on the soil chemistry of the surface 15 cm of soil in Dohne and Piet Retief Sourveld. Exclusion promoted the ingress of woody elements, including heath-like species, but the extent of ingress was related to water availability (rainfall, aspect), proximity of propagules, duration of protection, and accidental fires. Alien invasive woody species, in particular Acacia mearnsii established at all sites. Woody species were mostly bird- or wind dispersed, some had no known nearby population, although some Acacia species were herbivore-dispersed. The wettest grassland, Piet Retief Sourveld on a southern aspect, was transformed to a shrubland matrix (mainly Helichrysum splendidum) with tree clumps of forest precursor species (Rhus dentata, Halleria lucida, Myrsine africana, Buddleja salviifolia, Leucosidea sericea) and A. mearnsii. A species-rich grassland on the northern aspect had become dominated by tall Hyparrhenia rufa, with scattered shrubs of L. sericea and Helichrysum rogulosum. The southern aspect exclosure in Döhne Sourveld had developed an A. mearnsii - B. salviifolia savanna, with Cymbopogon excavatus, Themeda triandra and Tristachya leucothrix as common grasses. The northern aspect exclosure on Döhne Sourveld maintained a grassland character, although heath-like elements (Stoebe vulgaris, Erica aspalanthifolia) established. Protection of the Southern Tall Grassveld promoted an open savanna of exotic and indigenous Acacia and broadleaf species, an increase in life forms including the succulent Aloe maculata, and the transformation of a T. triandra - T. leucothrix sward to an Aristida junciformis sward. Ferns benefitted from exclusion of fire and herbivory. Fire and herbivory rather than soil properties would seem the primary determinants of the structure of sour grasslands.     

生长肥育猪饲粮中酒糟适宜用量的研究

用五种分别含酒糟0、5、10、15和20％的等能(DE 13.0—13.3MJ/kg)等氨(CP14％)饲粮研究酒糟使用比例对46—96kg长白×成华生长肥育猪生产性能的影响。五种饲粮使用同一酒糟专用添加剂预混料。结果表明,60kg前及60kg后二阶段猪的生产性能均以5％酒糟组为最高。在使用酒糟专用添加剂预混料后,生长肥育猪饲粮酒糟用量,前期以5—10％为宜,后期可用到15—20％。     

布鲁拉美利奴主效基因在绵羊育种中的应用

布鲁拉美利奴主效基因是在绵羊中发现的多羔基因，对绵羊的育种具有重要的意义。本文对该主效基因的发现过程、效应及作用机理、应用现状和前景作一综述，以供国内同类研究借鉴