感染反刍动物的几种常见梭状芽孢杆菌

梭状芽孢杆菌属的成员在自然界中是一种非常独特的种类，当其进入到反刍动物体内时，常会引起肌肉和软组织感染、肠道疾病和神经中毒性疾病。梭状芽孢杆菌引起反刍动物发病的机理通常是间接地通过其产生的一种或多种毒素(毒蛋白质)来致病。本文从肌肉和软组织感染、肠道疾病以及神经中毒性感染三个方面探讨了引起感染的梭状芽孢杆菌。     

以豆粕为原料制备反刍动物饲用肽的研究

本文通过正交试验,选用碱性微生物蛋白酶,研究得出酶解法制备大豆肽的最佳工艺参数:豆粕预处理条件为90℃水浴加热10min,酶解条件为底物浓度5%(W/V)、加酶量5万单位/g蛋白质、温度50℃、pH值10、酶解时间5.5h。蛋白质水解率达到25%,平均肽链长度为4.0。制得大豆肽粗蛋白质含量66.83%(DM)。并对制得大豆肽和原料豆粕的氨基酸含量进行分析。     

施肥和刈割日期对杂交狼尾草钙、磷、镁含量的影响及其与家畜需要的关系

研究了不同施肥处理和刈割日期对杂交狼尾草Ca、P和Mg含量的影响及其与家畜营养的关系,结果表明,有机肥的施用显著降低了植株Ca含量,对植株P和Mg含量无显著影响;随无机氮施用水平的提高,杂交狼尾草植株Ca和Mg含量显著提高,P含量显著降低;植株Ca、Mg含量均随刈割日期的推迟而显著提高,植株磷含量随刈割日期的推迟呈先降后升的规律;根据NRC推荐的饲养标准(奶牛、肉牛和绵羊),所有处理杂交狼尾草植株Mg含量均能满足家畜的需要,Ca:P为(0.95～2.67):1;利用杂交狼尾草饲喂高产奶牛时,应注意日粮中Ca、P的添加.     

Chemical and nutritional characteristics of Cannabis sativa L. co-products

Cannabis sativa L. is an annual herbaceous plant. It was used for centuries to obtain different products. In the last century, hemp cultivation was forbidden due to the psychoactive effects of tetrahydrocannabinol acid (THCA). In the last years, new strains, characterized by high cannabidiolic acid (CBDA) and low THCA level, were developed renewing the interest in hemp cultivation to obtain food or to extract essential oils from flowers. All these processes produce many residues with different chemical–physical characteristics. In order to evaluate their potential use also in animal nutrition, some hemp co-products were evaluated. Two different co-products of seed processes (flour and oil) and two co-products obtained trimming the flowers, differing in granulometry were used. The samples were analysed for chemical composition and evaluated in vitro using the gas production technique with buffaloes' ruminal inoculum. All hemp co-products showed interesting nutritional characteristics, such as crude protein content always higher than 20% on a dry matter basis, and high neutral detergent fibre concentration partially lignified. The in vitro gas production parameters at 120 h of incubation showed quite low fermentability testified by the low organic matter degradability and cumulative gas volume (OMD from 28.09 to 45.64% and OMCV from 110 to 164 ml/g, respectively). Also, the methane produced after 24 h of incubation was particularly low (from 1.78 to 11.73 ml/g dOM). These results could be due to the high lipid and ash amounts or to the CBDA content that probably affected the CH₄ formation processes. According to preliminary results obtained by this study, it is possible to hypothesize that these co-products could be useful to mitigate the methane production into the rumen. Further studies are necessary in order to evaluate the correct inclusion into the diet for ruminants.     

Mineral requirements of hair sheep in tropical climates

In this study, we evaluated the requirements of calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) for sheep hair growth. Experimental diets contained different levels of metabolizable energy [ME; 0.96, 1.28, 1.72, 2.18 and 2.62 Mcal/kg of dry matter, (DM), corresponding to 4.23, 5.64, 7.58, 9.61 and 11.55 MJ/kg DM]. The lambs' hair (n = 48) at 2 months of age presented an average body weight (BW) of 12.05 ± 1.81 kg. At the beginning of the experiment, eight animals were slaughtered as a reference group to estimate the initial empty body weight and body composition. Net mineral requirements (g/day) ranged from 0.73 to 0.71 g of Ca, 0.51 to 0.49 g of P, 0.026 to 0.026 g of Mg, 0.16 to 0.19 g of Na and 0.15 to 0.13 g of K for animals with a BW ranging from 15 to 30 kg and a daily gain of 100 g. The results of this study indicate that the net macromineral requirements for weight gain in Morada Nova lambs are different from the values commonly recommended by the Agricultural and Food Research Council.     

Gross anatomy,computed tomography,magnetic resonance imaging and bone mineral densitometry of the ovine metacarpo/metatarsophalangeal joint

This study was aimed to provide anatomical atlas of the ovine metacarpo/metatarsophalangeal joints using computed tomography (CT) scan and magnetic resonance imaging (MRI), as well as to investigate bone mineral density (BMD) and morphometric features of this joint. The limbs of twenty adult Sanjabi sheep were examined. Imaging was performed using a 16-slice multi-detector CT scanner and a 1.5 Tesla MRI scanner. The obtained images were correlated with corresponding anatomical sections. BMD was measured by Dual Energy X-ray Absorptiometry (DEXA) method. Also morphometric features included distance between metacarpal and metatarsal heads, width of metacarpal and metatarsal head, length, width and the height of the proximal sesamoid bones were measured. In MRI images, compact bones, ligaments and tendons showed less signal intensity (hypointense). The fatty tissue and bone marrow had more signal intensity (hyperintense), but articular cartilage and synovial fluid showed moderate signal intensity. BMD in the left hind limb was significantly higher than other three limbs (p ≤ 0.05). The length of proximal sesamoid bones in left forelimb was higher than right forelimb (p ≤ 0.05). The thickness of proximal sesamoid bones in left limbs was higher than those in their counterparts (p ≤ 0.05). The width of the medial head in the forelimbs was significantly greater than the hind limbs (p ≤ 0.05). The present results might be useful in managing the clinical techniques on this joint. Larger volume of the proximal sesamoid bones and wider medial head in the forelimbs compared to the hindlimbs impel this speculation that the centre of gravity is closer to the forelimbs.     

反刍动物营养学发展现代化进程的回顾及其展望

文章在回顾反刍动物营养学发展的现代化进程的基础上,分析了当前反刍动物营养学的发展趋势,并对其面临的历史任务和优先研究领域进行了论述和展望。     

Evaluation of the Feeding Value of Palm Press Fibre Using In Vitro Digestibility Techniques

Palm press fibre (PPF) was obtained from two sources, a small-scale oil palm processing unit and a large-scale factory processing unit, and its chemical composition was determined. In vitro digestibility techniques were used to assess the feeding value of untreated, defatted and sodium hydroxide-treated PPF. For the NaOH treatment, 0.5 g oven-dried PPF was treated for 24 h with 5% NaOH in three ways: treated and not washed (NaNW); treated and washed (NaW); and treated after milling (NAD).The results indicate that, on a dry matter basis, PPF is low in nitrogen (12–13 g/kg), moisture (37–90 g/kg) and ash (53–62 g/kg), but high in ether extract (269–355 g/kg), neutral detergent fibre (532–768 g/kg), acid detergent fibre (375–548 g/kg) and lignin (219 g/kg). The in vitro dry matter digestibility values were low for the samples from both sources, but the large-scale factory-processed PPF had higher in vitro dry matter digestibility (0.215 vs 0.166) and in vitro organic matter digestibility (0.196 vs 0.145). Defatting the PPF and treating it with 5% NaOH solution significantly (p<0.01) improved both the dry matter and organic matter digestibility. Washing the NaOH-treated PPF resulted in a higher digestibility of dry matter as against NaNW or NAD. These results suggest that defatting and treatment with 5% NaOH would improve the feeding value of PPF.     

亚麻籽在反刍动物中的应用

亚麻籽是反刍动物营养物质的一个重要来源,含有丰富的蛋白质、能量及必需脂肪酸。饲喂亚麻籽日粮可以提高肌肉中#-3必需脂肪酸的水平,从而改善肉质,优化人们饮食结构。文章介绍了亚麻籽的营养价值,以及通过在日粮中添加亚麻籽,对反刍动物消化吸收和肌肉性能的影响。     

反刍动物采食量测定方法的研究进展

在单位时间内反刍动物实际采食的饲草(料)数量称为反刍动物的采食量。据研究发现,反刍动物的采食过程是一个动态的过程,是由生物和非生物因素共同、相互的影响过程。准确地计算和测定反刍动物的采食量,是制定反刍动物的良好的营养方案的基础;是确定其补饲的重要依据。研究反刍动物的采食量对整个畜牧产业有重要的作用。本文对反刍动物在自由进食状态下的采食量的影响因素进行了阐述,并对其采食量的测定方法进行了深入的探讨和研究。