亚麻籽对羊肉营养成分及食用品质的影响

16只体重相近(34.06±1.68)kg的杂交公羔羊按单因素随机分组设计原理被分成4组,每组4只,饲喂添加了0%、5%、10%、15%亚麻籽的日粮进行为期60d的饲养和屠宰试验,研究了不同添加水平亚麻籽对绵羊肉营养成分及肉食用品质的影响,试验结果表明:亚麻籽对羊肉中的水分、粗蛋白、粗灰分、钙和磷的影响差异不显著(P>0.05),但却提高了羊肉中的粗脂肪含量(P<0.05);提高了羊肉的熟肉率、嫩度、大理石花纹(P<0.05),改善了羊肉的食用品质。     

黑头杜泊羊与和丰本地绵羊杂交后代羔羊生产性能及肉品质研究

为了客观评价黑头杜泊羊与和丰本地绵羊杂交后代羔羊的生产性能和肉品质,挑选杂交后代羔羊和本地绵羊羔羊各60只作为研究对象,测定其生产性能和肉品质的各项指标。结果表明:初生、1月龄杂交后代羔羊的体重显著高于本地绵羊羔羊(P<0.05),2月龄、3月龄、4月龄杂交后代羔羊的体重均极显著高于本地绵羊羔羊(P<0.01)。4月龄杂交后代羔羊的体高和胸围均显著高于本地绵羊羔羊(P<0.05),而体长和管围均极显著高于本地绵羊羔羊(P<0.01);6月龄杂交后代羔羊的体高显著高于本地绵羊羔羊(P<0.05),而体长、胸围、管围均极显著高于本地绵羊羔羊(P<0.01)。6月龄杂交后代羔羊的宰前活重、胴体重、净肉重、屠宰率、净肉重、净肉率、胴体产肉率、眼肌面积均极显著高于本地绵羊羔羊(P<0.01),脂尾重极显著低于本地绵羊羔羊(P<0.01);6月龄杂交后代羔羊的熟肉率显著高于本地绵羊羔羊(P<0.05),失水率显著低于本地绵羊(P<0.05);6月龄杂交后代羔羊肌肉水分、粗蛋白、粗灰分分别比本地绵羊羔羊提高2.12%(公)、3.13%(母)、7.28%(公)、3.48%(母)、23.65%(公)、16.90%(母)。说明杂交后代羔羊胴体品质得到明显改善,羊肉品质更加符合现代人民追求高蛋白、低脂肪的消费需求。     

宁夏黑绵羊肉质品质的研究

通过营养成分、肌纤维直径、贮存损失率、熟肉率等主要性状对宁夏黑绵羊肉质品质进行分析 ,并与滩羊进行比较。结果表明 ,黑绵羊肉营养价值与滩养相当 ,各种养分含量二者差异不显著 (P >0 .0 5 ) ,但黑绵羊肉中氨基酸含量较丰富 ,尤其是影响肉味的氨基酸含量较滩羊肉中高 (P <0 .0 5 )。黑绵羊肉肌纤维直径、贮存损失率较低 ,而熟肉率较高。该结果为今后充分利用黑绵羊种质资源和进一步选育提高提供了科学依据     

贵州威宁绵羊生产及屠宰性能测定与分析

为了探讨贵州威宁绵羊的生产及屠宰性能间的相关性,试验测定了89只纯种贵州威宁绵羊(45只成年羊、44只周岁羊)的屠宰性能、体尺性状、肉质性状、脏器系数和羊毛品质,并进行了显著性和相关性分析。结果表明:各年龄段威宁绵羊宰前体重、胴体重、净肉重均互呈极显著正相关(P0.01);体尺性状方面,各年龄段公母羊体高和管围差异均极显著(P0.01),周岁公母羊胸深差异显著(P0.05),而成年羊宰前体重、胴体重、净肉重、胸深、胸围之间互呈极显著(P0.01)正相关;肉质性状方面,周岁公母羊间水分含量差异显著(P0.05),且水分与滴水损失、剪切力呈显著(P0.05)正相关;脏器系数方面,各年龄段威宁绵羊宰前体重与肝脏、蹄重呈极显著正相关(P0.01);羊毛品质方面,威宁绵羊各年龄阶段的公羊与母羊毛丛长差异均显著(P0.05)。说明贵州威宁绵羊肉质性状处于中上水平,体重、体尺和屠宰性能低下,羊毛品质处于中等水平。     

草地藏系绵羊羊肉品质特性研究

对草地藏系绵羊羊肉的常规营养成分、总能、总糖、胆固醇、游离氨基酸、矿物质及羊肉嫩度进行了测定,并用分析了羊肉的可溶性蛋白含量及组分.研究结果表明草地藏系绵羊羊肉蛋白质含量高,脂肪含量适中,胆固醇含量低;游离氨基酸、矿物质含量丰富,肌肉细嫩;肌肉可溶性蛋白组分主要集中在分子量16.8 ku和96.8 ku之间.草地藏系绵羊肉质较好,具有较高的开发价值.     

西藏不同品种藏系绵羊育肥屠宰后肉品质的分析

为了分析不同品种藏系绵羊育肥后的羊肉品质,以阿旺绵羊、岗巴绵羊、彭波半细毛羊、安多绵羊4种3岁龄的藏系绵羊种公羊为研究对象,在同一饲养管理条件下,采用半舍饲+青草+秸秆+配方精饲料的方式育肥3个月后屠宰,取每只种公羊的背最长肌1 kg,进行羊肉品质分析。结果表明:①岗巴绵羊肉感官评分最高,总体可接受性也最好,其肉质特性为亮度值最大(L*值为43.09),光泽度最好;其肉剪切力为2 960 g、硬度为1 140 g、内聚力为0.419 kPa、弹力为0.25 N,质构品质最佳;其肉持水力为34.3%,蒸煮损失率为30.3%,肉质鲜嫩柔软。②岗巴绵羊肉的总脂肪酸含量、饱和脂肪酸含量、不饱和脂肪酸含量最高,分别为5.96、2.89、3.08 g/100 g。③除阿旺绵羊以外,以上3个品种藏系绵羊肉的必需氨基酸与总氨基酸的比值、必需氨基酸与非必需氨基酸的比值均超过或接近联合国粮农组织与世界卫生组织提出的标准,其中,安多绵羊肉的氨基酸总量以及必需氨基酸总量均为最高,分别为22.8、9.89 g/100 g干物质。由该试验结果可以得出,岗巴绵羊肉感官评分最高、食用品质最佳、加工品质最好;安多绵羊肉的营养价值最高。     

草地藏系绵羊羊肉品质特性研究

近年来,国内外对许多不同品种绵羊肉的品质特性从不同角度进行了较多的研究报道,但对草地藏系绵羊的产肉性能及羊肉品质特性研究极少,尚未见报道。现对草地藏系绵羊羊肉的品质特性进行研究报道如下。1材料与方法1.1羊只的选择2005年10月末,在四川省若尔盖县选择健康羊40只,按成年羯羊、成年母羊、周岁羯羊、周岁母羊各10只进行屠宰测定并取样。1.2分析样品的采集按绵羊胴体剖分法进行胴体剖分,即后腿肉、腰肉、肋肉、肩胛肉和胸下肉。对每只羊每个部位,按重量百分比对角线取肉样,混合后做成混合肉样用于常规营养成分、总能、总糖、胆固醇含…     

西藏阿里地区改则县野血牦牛屠宰性能及其肉品质特性研究

【目的】本试验旨在比较西藏阿里地区改则县不同性别野血牦牛的屠宰性能和牛肉营养成分和组成。【方法】随机选取了阿里改则县区域5～6岁、自然放牧、体况相近且良好的野血牦牛10头,公母各半,体重分别为(299.00±30.50)和(247.00±10.20)kg。通过开展屠宰试验研究阿里改则县区域野血牦牛屠宰性能、胴体性状及其肌肉营养品质特性。【结果】阿里野血公牦牛宰前活重、胴体重、净肉重、骨重和管围均显著或极显著高于母牦牛(P<0.05;P<0.01),其他体尺指标及屠宰指标均无显著差异(P>0.05)。公牦牛胴体长、胴体宽、胴体深、胴体胸深、后腿围、大腿肉厚和眼肌面积均显著或极显著高于母牦牛(P<0.05;P<0.01),而母牦牛背膘厚度极显著高于公牦牛(P<0.01)。公牦牛肌肉水分含量显著高于母牦牛(P<0.05),母牦牛肌内脂肪含量极显著高于公牦牛(P<0.01),蛋白质、胆固醇、矿物质、维生素含量及氨基酸组成在性别之间均无显著差异(P>0.05),氨基酸比例均为理性型优质蛋白质来源。脂肪酸组成上,阿里野血母牦牛肉中十五烷酸、棕榈...     

湖羊与三元杂交绵羊夏杜湖、夏澳湖肉质特性比较研究

旨在探究湖羊与三元杂交绵羊夏杜湖、夏澳湖肉质特性。本研究选择健康且出生体重相近的公羔((3.61±0.65) kg)随母哺乳至45天后集中断奶。断奶后分成3个处理组(湖羊组、夏澳湖组和夏杜湖组),每个处理15只公羔,3个处理的45只羔羊混合饲养至6月龄屠宰,并分析背最长肌组织形态及背最长肌的肉品质及营养成分。试验期饲喂全混合基础日粮。结果表明：1)相对于湖羊,三元杂交绵羊背最长肌亮度(L*)显著降低,熟肉率显著提高(P<0.05),但其对背最长肌pH、剪切力、失水率、红度(a*)和黄度(b*)无显著影响(P>0.05)。2)相对于湖羊,三元杂交绵羊背最长肌纤维直径和平均面积显著提高,但肌纤维数量和密度显著降低(P<0.05)。3)相对于湖羊,三元杂交绵羊背最长肌中粗蛋白、必需和非必需氨基酸的含量显著提高(P<0.05),但对总饱和脂肪酸、不饱和脂肪酸及微量元素(铜、铁、锌和锰)无显著影响(P>0.05)。4)夏杜湖和夏澳湖在背最长肌pH、剪切力、失水率、熟肉率、肉色、肌纤维数量、肌纤维面积、肌纤维密度、常规营养成分(水分、粗蛋白、粗脂肪、粗灰分)、微量元素...     

甘南藏羔羊肉品质检测分析

藏羊肉品质上乘,味道鲜美,在西北地区享有盛誉,是蒙、藏人民不可缺少的肉食品,藏羔羊肉更是长期受到广大消费者青睐。试验以藏羔羊肉为研究对象,从肉用品质、营养成分含量和质构特性方面评价其品质特性,并与同一饲养环境下的成年藏羊进行对比分析,旨在分析研究藏羔羊肉的营养品质,从而为藏羊最佳屠宰年龄提供参考依据。结果表明:藏羔羊肉表面亮度(L*值)显著高于成年藏羊肉(P<0.05),红色度(a*值)显著低于成年藏羊肉(P<0.05),而黄色度(b*值)、pH值两者间无显著差异(P>0.05),熟肉率藏羔羊肉比成年藏羊肉高4.77%(P<0.05),失水率比成年藏羊肉低8.55%(P<0.05),剪切力较成年藏羊肉低1.18%(P>0.05);水分、粗灰分含量两者间无显著差异(P>0.05),藏羔羊肉蛋白质含量20.69%,比成年藏羊肉高12.26%(P<0.05),脂肪含量显著低于成年藏羊肉(P<0.05);藏羔羊肉硬度4 219.85 g、胶黏性2 448.65 g、咀嚼性1 387.39 g,分别比成年藏羊肉低17.12%(P<0.05)、27.36%(P<0.05)、2.20%(P<0.05)。说明藏羔羊肉具有高蛋白、低脂肪的特点,其嫩度高、口感好,符合人口感适宜范围。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。