添加复合缓冲剂对高精料饲喂泌乳奶山羊乳品质的改善及机制

目的:探讨复合缓冲剂对高精料饲喂泌乳期奶山羊乳品质及机体健康状态的影响。方法:选取8只体质量接近的泌乳中期萨能奶山羊,随机分为高精料组(high concentrate diet group,HG)(精粗质量比60∶40)和缓冲剂组(buffering concentrate group,BG)(高精料中添加复合缓冲剂)。实验共20周,每周统计奶山羊产乳量,每周检测乳成分含量;至第19周,采集瘤胃液和血液样品,测定瘤胃液p H值及脂多糖(lipopolysaccharides,LPS)含量及血液中相关生化指标。结果:与HG相比,BG的奶山羊平均日产乳量、乳中乳蛋白率、乳脂率及乳糖含量都高于HG,其中乳脂率显著高于HG(P0.05)。HG奶山羊瘤胃p H值一直低于BG,且出现了亚急性瘤胃酸中毒症状,其中瘤胃液中LPS含量极显著高于BG(P0.01);生化指标检测结果显示:HG奶山羊血液中碱性磷酸酶、谷丙转氨酶、谷草转氨酶的活性都高于BG,且差异显著(P0.05)。结论:给泌乳奶山羊高精料饲料中添加复合缓冲剂可以改善泌乳期奶山羊乳品质和产乳量,其机理可能与复合缓冲剂缓解高精料所致的瘤胃p H值下降、减少代谢异常产物的产生,从而改善机体的健康状态有关。     

Intramuscular fatty acid profile of longissimus dorsi and semitendinosus muscle from Pateri goats fed under traditional feeding system of Sindh, Pakistan

The present study was undertaken to assess the intramuscular fatty acid composition of different muscles taken from male Pateri (n=15) goats, reared on naturally grown grasses, leaves and pods of Acacia nilotica and crushed cereal, under traditional way of feeding. Goats were slaughtered with an average weight of 68±7kg and age 12±1 month. The samples were taken from longissimus dorsi region (between the 12th and 13th rib) and distal region of semitendinosus muscle. Results of total fat content and fatty acids composition does not show significant (P>0.05) variation among muscles investigated. The fatty acid composition of muscles studied were primarily composed of oleic (31.50-33.38%), followed by palmitic acid (19.84-22.05%) and stearic acid (22.25-24.91%) respectively. Muscle tissue in general contained an average 51.13% of saturated fatty acids and 48.87% of unsaturated fatty acids. The mean conjugated linoleic acid was found 0.41%, 0.43% and 0.47% in ribeye and loin portion of longissimus dorsi muscle and distal region of semitendinosus muscle, respectively.     

Assessing dairy goat welfare in intensive or semi-intensive farming conditions in Mexico

We aimed to verify whether a low number of relevant animal-based indicators was able to discriminate 33 semi-intensive (grazing during the day and confinement during the night with access to an outdoor paddock; S-INT) and 8 intensive farms (permanent confinement with access to an outdoor paddock; INT) located in the Mexican semi-desert. In addition, we implemented the resource-based assessment scheme Animal Needs Index (ANI) with the identified animal-based indicators to compare the overall level of welfare in INT and S-INT. In particular, we used a protocol made up of 2 parts. The first comprised 4 evaluation sheets (locomotion, flooring, environment, management) and resource-based indicators derived from ANI, and the second one comprised a set of validated animal-based measures focusing on physical conditions and clinical signs of disease derived from the Animal Welfare Indicators scheme and reported in 2 additional sheets. The scoring system was also derived from ANI, with partial scores for each sheet to be summed to obtain the total score. A total of 1,116 dairy goats were assessed. All the observations and recordings were performed by an expert veterinarian evaluator assisted by an auxiliary, and longevity was retrieved from the farm records. The prevalence of animals displaying dirtiness, ocular discharge, abscesses, and claw overgrowth were higher in INT than in S-INT. Disbudding was routinely performed in INT only. Therefore, scurs, indicating improper disbudding, were recorded only in INT. In addition, the longevity of goats raised in S-INT was higher than in INT. Conversely, the prevalence of goats affected by anemia (i.e., FAMACHA scores >2) or lean (i.e., body condition score <2) tended to be higher in S-INT than in INT. No significant differences between the 2 groups of farms were detected for wounds, nasal discharge, integument alterations, fecal soiling, uterine prolapse, and subclinical mastitis. The results obtained using only animal-based measures were confirmed when resource-based variables were also included in the assessment, as 3 out of 6 sheets of the evaluation scheme (i.e., flooring, environment, and health—physical conditions) were scored higher in the S-INT than in the INT. As a consequence, the total score was also higher for S-INT than for INT. We conclude that the selected set of validated animal-based measures was able to discriminate between farms from different production systems. In particular, higher welfare levels were observed in S-INT farms, where the animals were allowed to spend most of the day on natural pasture, compared with INT farms, where the animals were constantly confined. Nevertheless, a certain degree of improvement should also be promoted in terms of anemia and body condition in S-INT farms.     

Babassu Cake in Goat Diet Improves Growth Performance and Quality and Fatty Acid Profile of Meat

Babassu cake (BC) is a byproduct from oil extraction from babassu palm kernels. The aim of this study is to evaluate the effect of including BC levels (0%, 6%, 12%, and 18% on a dry matter basis) in the diet of 28 kids (n = 7 per treatment) on productive performance, and quality and profile of fatty acids (FA) of meat (loin). The inclusion of BC in the diet increases dry matter intake (P = 0.0005), average daily gain (P = 0.0222), slaughter body weight (P = 0.0424) of goats, and increased fat (P = 0.0424), unsaturated fatty acids (P = 0.0041), monounsaturated fatty acids (P = 0.0163), and isomers of conjugated linoleic acid (rumenic acid; P = 0.0002) content and polyunsaturated fatty acids:saturated fatty acids ratio (P = 0.0430) of meat. However, there are reductions in the levels of stearic acid (P < 0.0001) and saturated fatty acids (P = 0.0041) and in the thrombogenicity index (P = 0.0219) of meat. The inclusion of BC in the goat diet improves its growth performance and the quality and fatty acid profile of meat.     

Evaluation of bulk tank milk PCR and bulk tank milk modified ELISA tests for the detection of paratuberculosis at the herd level in goat and sheep dairies in Ontario,Canada

Early identification of dairy goat herds and dairy sheep flocks infected with Mycobacterium avium ssp. paratuberculosis is important for controlling this infection and minimizing economic losses. The objective of this study was to evaluate 2 bulk tank milk (BTM) paratuberculosis tests (PCR and modified ELISA) as potential herd-level tests. These tests were compared with the results obtained from testing 20 randomly selected lactating animals per farm (>2 yr) with an individual animal test (fecal culture, fecal PCR, serum ELISA, and milk ELISA). The study was conducted using 29 dairy goat herds and 21 dairy sheep flocks in Ontario, Canada, visited between October 2010 and August 2011. The sensitivity of the BTM PCR was poor in both the dairy goat herds (0.0%) and dairy sheep flocks (25.0%), but exhibited 100% specificity in both species. In comparison, the BTM modified ELISA demonstrated higher sensitivity. In goats, sensitivity ranged from 33.3 to 34.8% when fecal culture and PCR were the reference tests, respectively (specificities were both 100%), and 71.4 to 87.5% when the milk and serum ELISA, respectively, were the reference tests (specificities were 86.4 and 95.2%). The BTM modified ELISA in dairy sheep demonstrated comparable sensitivities, but lower specificities. When fecal culture and PCR were the reference test, sensitivities were 50.0 and 46.7%, respectively (specificities were 77.8 and 83.3%). The sensitivities when the milk and serum ELISA were the reference tests were 87.5 and 72.7%, respectively (specificities were 92.3 and 100%). Fecal PCR was the only individual animal test to identify significantly more farms as positive than the BTM PCR and modified ELISA test in both species. Therefore, whereas the BTM modified ELISA may provide an organization or control program with a high level of confidence that a BTM-positive farm is actually positive (high positive predictive value), if a producer wishes to increase the odds that a positive farm will test positive, so as not to miss an infection, then sampling and testing 20 animals with fecal PCR will better meet that objective.     

苏尼特羊、巴美肉羊和乌拉特山羊的肉品质和挥发性风味物质比较

为了探究品种对羊肉品质和风味的影响,选取12月龄苏尼特羊、巴美肉羊和二狼山白绒山羊(乌拉特山羊)各12只,测定其屠宰性能,再分别取股二头肌测定肉品质和挥发性风味物质并进行比较。结果表明:巴美肉羊的胴体质量、背膘厚、a^*值均显著高于苏尼特羊和乌拉特山羊(P<0.05),说明其屠宰性能较好,肉色较红;苏尼特羊的pH显著高于乌拉特山羊(P<0.05),而巴美肉羊与二者之间无明显差别(P>0.05)。品种对挥发性成分的相对含量和构成影响很大,电子鼻测定结果表明苏尼特羊、巴美肉羊和乌拉特山羊的气味存在差异,进一步对比挥发性风味物质发现,苏尼特羊肉中醛、醇及酮类化合物的总相对含量较高。气相色谱-质谱联用检测出乌拉特山羊肉中风味物质较其他两种丰富,通过相对气味活度值(ROAV)筛选出庚醛、辛醛、壬醛、反-2-壬烯醛、1-辛烯-3-醇、反-2-癸烯醛和十二醛可作为三种羊肉共有的关键风味物质,其中壬醛对苏尼特羊肉风味贡献最大,而巴美肉羊和乌拉特山羊肉中贡献最大的风味物质为1-辛烯-3-醇。总体上,巴美肉羊的屠宰性能较优良且肉色略红,在风味方面,不同品种的羊肉其关键风味物质存在差异。     

Optimizing colour quality of modified atmosphere packed sliced meat products by control of critical packaging parameters

Distribution of fat, muscle and bone tissues was studied in bucks, wethers and doe Jebel Akhdar (JA) Omani goats raised under intensive management and slaughtered at 11, 18 or 28 kg body weight (BW). Weight of individual tissues was expressed as percentage of total respective tissue weight in the half carcass. Weight of total body fat in the empty body weight (EBW) ranged between 7.6% in bucks at 11 kg BW and 23.5% in does at 28 kg BW. At 18 kg BW, JA goats had higher TBF, carcass and non-carcass fat than those slaughtered at 12 kg BW (P<0.001). Does and wethers had a faster rate of deposition of carcass and non-carcass fat relative to EBW. Therefore, they had higher fat content (P<0.001) than bucks at 28 kg BW. The highest proportion of fat in the body was deposited intermusculary whereas the omentum constituted the highest non-carcass fat proportion. About 55% of the musculature in JA goat carcasses was found in muscle groups of the proximal hind leg, around the vertebral column and in the proximal forelimb (expensive muscle groups). Bucks had higher proportions of musculature in the forequarter (P<0.001) and intrinsic muscles of the neck but lower proportions of muscles at the proximal hind limb (P<0.001) than does and wethers. About 51% of the total skeleton was found in the axial skeleton, 22–23% in the forelimb and 22–23% in the hind limb of JA goats. There were few sex or slaughter weight effects on proportions of bone weight in the skeleton. In general, slaughter weight and sex effects on tissue distribution were more pronounced in the fat tissue. The magnitude of these effects on muscle and bone tissues was small and is unlikely to have economic impact on meat production from goats.     

Learning to learn during visual discrimination in group housed dwarf goats (Capra hircus).

Using an automated learning device, we investigated "learning to learn" by dwarf goats (Capra hircus) in what was for them a familiar environment and normal social settings. Nine problems, each consisting of four discriminable black symbols, each with one S+ and three different S-, were presented on a computer screen. Mean daily learning success improved over the course of the first four problems, and the improvement was maintained throughout the remaining five problems. The number of trials to reach the learning criterion decreased significantly beginning with problem four. Such results may be interpreted as evidence that the goats were developing a learning set. In the present case, the learning set appeared to have two components. One involved gaining familiarity and apparent understanding of the learning device and the basic requirements of the discrimination task. The second component involved learning potential error factors to be ignored, as well as learning commonalities that carried over from one problem to the next. Among the error factors, evidence of apparent preferences for specific symbols was seen, which had a predictable effect on performances. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responses of intake,digestibility and nitrogen utilisation in goats fed low‐quality roughages supplemented with tree foliages

BACKGROUND: A meta‐analysis of data containing 127 different dietary treatments with 593 goats from 30 published studies was performed to explain the effects of foliage supplementation to low‐quality roughages on intake, digestibility and N utilisation in goats. RESULTS: Basal dry matter (DM) intake decreased linearly with increasing foliage level (FL) in diets and foliage crude protein (CP) intake, whereas total DM intake increased linearly with increasing FL and CP intake from foliages and quadratically with increasing concentration of neutral detergent fibre (NDF) in foliages. The digestibility of DM and CP increased linearly with increasing FL and CP concentration in basal roughages and foliage CP intake. The greater concentration of NDF in foliages and roughages decreased CP digestibility linearly. Intakes of digestible DM and CP increased quadratically with increasing FL, with plateau levels of 36.4 and 5.52 g kg^?1 (body weight)^0.75 in response to 490 and 740 g kg^?1 FL respectively. Faecal N, urinary N and N retention increased linearly with increasing FL and foliage CP intake. CONCLUSION: Responses of goats fed basal roughages supplemented with foliages are influenced by the quality and quantity of foliages and quality of roughages. Up to 490 g kg^?1 FL can be incorporated in diets for better feed utilisation and animal performance, beyond which nutrient utilisation may be adversely affected. Copyright © 2009 Society of Chemical Industry