Effects of tannin on selection by sheep of forages containing alkaloids,tannins and saponins

BACKGROUND: Mixtures of plant species provide biochemical diversity to pastures which may enhance productivity while decreasing reliance on herbicides and insecticides. All plants contain secondary metabolites (PSMs) that interact in plant communities in a variety of ways. For instance, tannins are a group of highly reactive chemical compounds with the potential to interact with other PSM such as alkaloids and saponins, neutralizing their negative effects. Our objective was to determine whether tannins modify the foraging behavior of sheep grazing on varieties of alfalfa, birdsfoot trefoil and tall fescue with high and low concentrations of saponins, tannins and alkaloids, respectively. RESULTS: Lambs that received intraruminal infusions of tannins increased their consumption of the high‐saponin variety of alfalfa and the high‐alkaloid variety of tall fescue relative to lambs not infused with tannins (controls). Lambs infused with tannins and then offered choices among the three high‐PSM varieties of the forages also manifested higher consumption of the high‐alkaloid variety of tall fescue than control lambs. In contrast, lambs infused with tannins reduced their consumption of the high‐tannin variety of birdsfoot trefoil. Thus lambs modified their foraging behavior as a function of the presence/absence of tannins in their rumens. CONCLUSIONS: These results indicate that ruminants are able to discriminate the specific post‐ingestive effects of forage varieties with high concentrations of PSM, and that PSM complementarities are likely to increase the efficiency of use of diverse forages with different biochemistries. Copyright © 2009 Society of Chemical Industry     

不同处理棉秆饲料在羊瘤胃中降解的动态规律

选用3只装有永久性瘤胃瘘管体重为(30±2)kg的成年卡拉库尔羊,研究不同化学处理后的棉花秸秆在瘤胃内的降解规律,在6、12、24、36、48、72 h测定干物质(DM)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的含量,计算相应营养物质的降解率。结果表明:(1)采用“3.5%尿素 2.5%石灰 3.0%食盐”复合处理效果最好,DM、NDF、ADF的有效降解率提高最为显著(P<0.01);(2)棉花秸秆中DM、NDF、ADF的快速可降解部分以及慢速可降解部分的降解率随处理方法不同而呈现差异。     

Characterization of major and trace minerals,fatty acid composition,and cholesterol content of Protected Designation of Origin cheeses

Cheese provides essential nutrients for human nutrition and health, such as minerals and fatty acids (FA). Its composition varies according to milk origin (e.g., species and breed), rearing conditions (e.g., feeding and management), and cheese-making technology (e.g., coagulation process, addition of salt, ripening period). In recent years, cheese production has increased worldwide. Italy is one of the main producers and exporters of cheese. This study aimed to describe mineral, FA, and cholesterol content of 133 samples from 18 commercial cheeses from 4 dairy species (buffalo, cow, goat, and sheep) and from 3 classes of moisture content (hard, <35% moisture; semi-hard, 35–45%; and soft, >45%). Mineral concentrations of cheese samples were determined by inductively coupled plasma optical emission spectrometry, and FA and cholesterol contents were determined by gas chromatography. Moisture and species had a significant effect on almost all traits: the highest levels of Na, Ca, and Fe were found in cheeses made from sheep milk; the greatest level of Cu was found in cow milk cheese, the lowest amount of K was found in buffalo milk cheese, and the lowest amount of Zn was found in goat cheeses. In all samples, Cr and Pb were not detected (below the level of detection). In general, total fat, protein, and minerals significantly increased when the moisture decreased. Buffalo and goat cheeses had the highest saturated FA content, and sheep cheeses showed the highest content of unsaturated and polyunsaturated FA, conjugated linoleic acid, and n-3 FA. Goat and sheep cheeses achieved higher proportions of minor FA than did cow and buffalo cheeses. Buffalo cheese exhibited the lowest cholesterol level. Our results confirm that cheese mineral content is mainly affected by the cheese-making process, whereas FA profile mainly reflects the FA composition of the source milk. This study allowed the characterization of mineral and FA composition and cholesterol content and revealed large variability among different commercial cheeses.     

简析内蒙古烤羊腿制作工艺

烤羊腿制作工序复杂 ,须经选料、初加工、腌渍入味、保护及优化、烤制成熟等工序 ,各道工序操作严格 ,成品味感美 ,色红亮 ,地方风味足 ,符合卫生标准     

Ruminal metabolism of leafy spurge in sheep and goats: A potential explanation for differential foraging on spurge by sheep,goats, and cattle

Leafy spurge (Euphorbia esula) is an introduced forb that is invading western rangelands. Goats (Capra hircus) readily graze the plant, but cattle (Bos tarus) generally and sheep (Ovis aries) locally appear to develop conditioned flavor aversions to leafy spurge. They either avoid the plant entirely or graze it reluctantly. We hypothesized that: (1) a diterpene diester that can occur in leafy spurge was an aversive agent, and (2) diet selection differences among ruminant species may be partly a function of differential ruminai metabolism of aversive phytochemicals, and further that cattle and sheep may be reluctant to graze leafy spurge because their ruminai microbes do not metabolize certain leafy spurge chemicals as do ruminai microbes in goats. Sheep did not develop an aversion to a novel food when its consumption was followed by an intravenous injection of ingenol 3,20-dibenzoate (P=0.34). Sheep did develop an aversion to a novel food when its intake was followed by a dose of leafy spurge fermented with sheep ruminai digesta, but not when followed by a dose of leafy spurge fermented with goat ruminai digesta (P= 0.03). This suggests that goat ruminai microbes may modify leafy spurge such that it does not elicit an aversion in sheep.This research was supported in part by a grant from the Cooperative States Research Service (91-38300-6158). All experimental procedures with ruminants followed a protocol approved by the U.S. Sheep Experiment Station's Animal Care and Use Committee. Mention of trade names or companies does not constitute an implied warranty by USDA or the authors.     

Nitrogenous constituents in the urine of cattle,sheep and goats

Ten samples of urine from dairy cows, five from sheep and four from goats were analysed to assess the distribution of urinary nitrogen (N) among various chemical constituents in order to gain a better understanding of the reactions undergone by urinary N in soil. Total N in the cow urine ranged from 6.8 to 21.6 g N litre^?1, of which an average of 69% was present as urea, 7.3% as allantoin, 5.8% as hippuric acid, 3.7% as creatinine, 2.5% as creatine, 1.3% as uric acid, 0.5% as xanthine plus hypoxanthine, 1.3% as free amino acid N and 2.8% as ammonia. In the sheep urine, total N ranged from 3.0 to 13.7 g litre^?1 of which an average of 83 % was present as urea; creatine accounted for 5.3% of the N; hippuric acid and allantoin both accounted for 4.3%, while each of the other constituents amounted to less than 1% of the total N. The goat urine was similar to the sheep urine but with a lower ratio of creatine to creatinine and a somewhat higher proportion (2.0 %) of the total N as amino acid.     

北方质次土种绵羊皮制作光面毛革生产工艺的研究

采取酶助浸水、分步脱脂、酸性酶软化、铬—铝结合鞣制、KS—1树脂复鞣剂和改性戊二醛复深填充、分次加脂的工艺路线，以蒙古路土种绵羊皮为原料生产光面毛革，对浸水酶、软化酶、复鞣材料用量及软化、浸酸时间等重要工艺参数进行了优化，得出了利用质次土种绵羊皮加工光面毛革的工艺，所得坯革感观和机械性能良好。     

磺胺二甲嘧啶的东北细毛关体内的代谢动力学研究

选用紫外分光光度计法,研究了静脉推注磺胺二甲嘧啶(SM2)后,在成年东北细毛羊体内的药物代谢动力学过程.主要药物代谢动力学参数初始血药浓度(A)为(17.6359±2.57)mg@L-1,分布半衰期(t1/2α)为(0.3006±0.04)h,消除半衰期(t1/2β)为(4.6635±1.53)h,消除速率常数(β)为(0.1486±0.051)h-1,总清除率(CLB)为(0.6677±2.86)100mL@kg-1@h-1,中央室消除速率常数(Ke1)为(0.2763±0.035)h-1,总表观分布容积(Vd)为(4.4933±0.37)100mL@kg-1,有效抑菌浓度维持时间(Tcp)为8.56h,药一时曲线下面积(AUC)为(149.7732±19.45)mg@L-1.h-1.为此,确认磺胺二甲嘧啶(SM2)对东北细毛羊为短效药物.