Nutritional management of recurrent colic and colonic impactions

Although diagnosis and treatment of horses with colic have improved in the last 30 years, horses with recurrent colic can be a diagnostic and management challenge for both owners and veterinarians, and colic remains a high priority health concern of owners (Mellor et al. 2001 ). Nutritional management of these cases is often based on previous experience combined with recommendations from the evidence‐based literature. This review will briefly summarise the aetiologies of recurrent colic and primarily focus on evidence‐based nutritional management of colonic impactions, sand enteropathy, inflammatory bowel disease, and idiopathic recurrent colic, which is limited. Additional topics to be covered elsewhere in this series that are relevant to this topic include nutritional management of gastric ulceration, liver disease, colitis, geriatric horses, and feeding the horse pre‐ and post surgery.     

反刍动物小肽的生理特征与营养研究进展

小肽是动物降解蛋白质过程中产生的中间产物,蛋白质在动物消化道内降解成游离氨基酸和小肽后被吸收。大量试验结果表明,反刍动物以肽吸收为主要形式,并且其在氨基酸消化、吸收和降解中起着重要作用。作者对小肽生理特征及营养等方面的研究现状进行了综述。     

m6A表观遗传修饰及其调控机制研究进展

N⁶-甲基腺嘌呤（N⁶-methyladenosine,m⁶A）修饰是现阶段发现的真核生物体内最广泛的RNA表观遗传修饰方式,近年来研究显示,m⁶A在真核生物间具有较高的保守性,在基因表达及细胞命运调控中发挥着关键作用,且对mRNA的可变剪接、定位、翻译及稳定性有较大影响。现有的m⁶A修饰检测技术可以较为准确、高效地检测出生物样本中的m⁶A修饰丰度,并能快速、简便地进行m⁶A修饰的高通量测序,以及在单碱基分辨率下检测m⁶A修饰在RNA上的位置。尽管m⁶A修饰相关调控蛋白对畜禽复杂经济性状的影响近年来已有少量报道,但其中的作用机制仍未得到充分阐明。大量人类及模式生物上的研究表明,m⁶A修饰相关蛋白能够影响生长发育、繁殖、热应激、炎症及癌症等生物学过程,为探究畜禽m⁶A修饰参与复杂性状调控机制提供一定的借鉴意义。作者主要从m⁶A甲基化修饰相关蛋白（甲基转移酶、去甲基化酶及读取蛋白）、m⁶A检测技术、m⁶A对哺乳动物复杂性状的调控机制、m⁶A与其他表观修饰的互作机制等方面进行阐述,为m⁶A在畜禽遗传育种中的应用提供新的见解。     

日粮营养水平对奶牛乳蛋白合成的影响及其作用机理的研究进展

乳蛋白作为乳中重要的组成成分,含有人体所需的几乎所有必需氨基酸。然而,奶牛乳蛋白的合成受很多因素影响,如日粮组成、遗传因素、饲养环境等,但具体影响机制尚不明确。因此,研究乳蛋白合成机理,结合营养调控措施提高其在乳中的含量,成为目前研究的热点和重点。作者就目前日粮营养水平对奶牛乳蛋白合成的影响及其作用机理的研究进行了综述。     

mRNA差异显示技术、PCR技术及其在动物营养研究中的运用

21世纪将是生命科学的世纪。当前,世界各国都将分子生物学纳入本国科技发展的重点。分子生物学技术的迅速发展为营养科学探索必需营养缺陷的分子基础提供了强有力的实验工具。本文旨在对mRNA差异显示技术、PCR技术等两种最常用的生物技术手段的原理、特点及其在动物营养研究中的应用作一综述。     

改善奶牛氮磷利用效率的营养策略

氮磷在奶牛生长、发育和生产过程中发挥着重要作用,但在实际生产中,饲粮氮磷含量往往过高,而奶牛对于氮磷的利用效率普遍偏低,这不仅会造成饲料资源的浪费,而且加重了氮磷的排放,导致严重的环境污染.合理减少饲粮氮磷含量、提高奶牛机体对氮磷的利用效率具有重要的现实意义.因此,本文主要从影响氮磷利用效率的因素,以及改善奶牛氮磷利用效率的营养策略2个方面进行了综述,以期为提高奶牛氮磷利用效率,减少氮磷向环境的排放,提高奶牛场经济和生态效益提供理论依据.     

Phenotypes Including Immunocompetence in Scavenging Local Chicken Ecotypes in Tanzania

A study was conducted to determine the variations in physical characters and immunocompetence among scavenging local chicken ecotypes in Tanzania. Eighty-four adult scavenging local chickens from four eco-climatic regions of Tanzania were studied. Measurements of adult body weight, body length, shank length and egg weight and observations of plumage colour and pattern, earlobe colour, skin colour and the shape of the comb were conducted. The antibody response to sheep red blood cells, serum haemolytic complement and the cutaneous response to phytohaemagglutinin-P were assessed. Five ecotypes were identified and named Mbeya, Morogoro-medium, Ching'wekwe, Kuchi and Singamagazi. Singamagazi and Kuchi were significantly heavier, with longer shanks and heavier eggs than the other ecotypes. The average adult body weight for males ranged from 1621 g (Mbeya) to 2915 g (Singamagazi). Average female weights ranged from 1108 g (Morogoro-medium) to 2020 g (Singamagazi). Mean egg weights ranged from 37.65 g (Ching'wekwe) to 45.61 (Singamagazi). The Kuchi had mostly rose and walnut combs, while the other ecotypes were mostly single combed. In each ecotype there were chickens with a high or low antibody response to red blood cells, but there was a significant difference between the ecotypes.     

早期断奶仔猪营养性腹泻的分析及防治

仔猪腹泻是一种严重制约养猪业发展的疾病,其发生由应激、环境、营养等多种因素造成。本文主要从营养方面阐述了早期断奶仔猪发生腹泻的原因,并综合近年研究资料,论述了各种营养因素对仔猪营养性腹泻的改善作用,为研究合理的断奶仔猪日粮提供理论依据。     

奶牛营养平衡与需要量

随着我国奶牛业的快速发展,奶牛对日粮营养平衡的要求越来越高,而正确理解奶牛的营养需要对制定营养平衡的日粮配方非常重要。本文主要从能量、蛋白质、纤维、矿物质和维生素方面探讨奶牛的适宜营养需要量。