Determination of the average duration of food in the digestive tract of sheep

The average time the test feed remains in sheep was determined with ewes during three stages of the reproduction cycle. The feed was labelled with 51Cr2O3. Experiment conditions are described under which the experiments can be carried out within the permissible limits.     

Rate of passage of a non-traditional diet through the digestive tract in sheep

The rate of passage of experimental diets based on non-conventional feeds through the alimentary tract of rams was studied. The composition of diets was as follows: barley straw (D-2, D-1), conditioned beech sawdust (D-2, D-1), waste cellulose fibre (D-2, D-1), lactosylureide (D-2), peanut waste (D-2), urea (D-1), wood molasses (D-2, D-1) and mineral supplement (D-2, W-1). The control feed (K) contained straw, barley, beet molasses and mineral supplement. As a marker was used a single application (50 g) of polyethylene (PE), particle size 0.4 mm and specific weight 0.924, which formed 3.9, 3.5 and 4% of the diet dry matter. After 10 days the recovery of polyethylene amounting to 81.23% (D-2), 84.78% (D-1) and 86.6% (K) was established. The polyethylene losses occurred most probably at its administration in feed (10-12%), elapsing of polyethylene excreted after 10 days following the administration (0.5-1.5%) and by potential retention in rumen and large intestine. Maximal excretion of feces was observed during the second day after administration of the markered feed; after three days the excretion was as follows: group D-2-62%, group D-1-57% and control group 75.6%. A longer retention time in rumen at feeding D-2 and D-1 diets can be contributed to a high content of fibre in these diets. The digestibility of dry matter in diet D-2 amounted to 61.2%, i n diet D-1 to 62.3% and in control diet to 68.7%. Higher digestibility of feed is in accordance with its higher excreting. As shown by the results, the diets based on non-conventional feeds (secondary wood sources) lead to the prolongation of feed retention time in rumen and slow down the rate of passage through the alimentary tract.     

羊消化道寄生虫种类及防治措施

羊消化道的寄生虫病较多,不仅能不同程度地影响羊只的生长发育,降低生产性能,严重的还能造成羊只死亡,对养羊业危害较为严重。笔者概述了羊消化道寄生虫种类及不同地区、季节、年龄羊消化道寄生虫的感染情况,并介绍不同羊消化道寄生虫常用的驱虫药及防治策略。     

Changes in motility and ph in the digestive tract of experimentally overfed sheep.

Motility of the digestive tract of 4 sheep was studied with radiotelemetric equipment. After base line records were made, each sheep was overfed with 70 g of grain per kilogram of body weight. The ruminoreticulum did not become static until the ingesta pH was less than 5. The cecum had the same patterns of motility and pH as did the ruminoreticulum, but these returned to normal more quickly in surviving sheep. The motility patterns of the abomasum and the small intestine were more erratic. Results indicated that considerable quantities of grain (substrate for microbial growth) reached the cecum before ruminoreticular motility was inhibited.     

绵羊消化道中乳酸菌的筛选及鉴定

试验采集了4只瘘管蒙古羯羊的瘤胃液和食糜,分离和筛选乳酸菌,利用传统分类法和16S rRNA部分序列分析法鉴定绵羊消化道中的乳酸菌.结果表明,分离到的绵羊瘤胃液和食糜中乳酸菌属于植物乳杆菌.     

益生菌在消化道中的抑菌作用

益生菌及其代谢产物有多种抑菌作用,抑菌效果受到动物消化道环境的影响。益生菌不但可以抑制病原菌的生长,而且可以提高动物的免疫力。文章综述了益生菌的抑菌作用,以及其受动物消化过程的影响。     

Participation of bile and pancreatic juice in the secretion of endogenous nitrogen into the digestive tract of sheep

The amount of bile and pancreas juice excreted and the amount of urea-N and total-N discharged by the bile and pancreas juice into the duodenum was established in eight experiments with two full-grown sheep of the merino species and with a live weight of 50 kg. For this purpose they had permanent cannulae for the measuring of the passage of bile and pancreas juice which was carried out at 1-hour intervals in the course of 24 hours beginning at 7 o'clock in the morning. During 24 hours 245.3 +/- 6.3 mg urea and 4,418.1 +/- 85.8 mg total-N were discharged with bile and pancreas juice, of which 186.9 +/- 9.6 mg urea and 2,095.3 +/- 119.7 mg total-N were discharged in the bile and 58.5 mg urea-N and 2322.8 +/- 52.9 mg total-N were discharged in the pancreas juice. The amount of pancreas juice secreted and its nitrogen is constant in the course of the day (between 7 a.m. and 7 p.m.) and of the night (between 7 p.m. and 7 a.m.) In the daytime the secretion of bile and its nitrogen is significantly higher than at night. (p less 0.05). The concentration of urea-N and of total-N remained constant throughout the whole day. The amount of bile and pancreas juice secreted correlated greatly significantly with the amount of nitrogen (urea-N and total-N) discharged in bile and pancreas juice. The results indicate that, within the enterohepatalous circulation of endogenous urea, its secretion in bile and pancreas juice is quantitatively less important. The amount of total-N which gets from the endogenous pool into the duodenum is high and corresponds to approximately one third of the metabolic nitrogen which the animals consume daily with their feed.     

Absorption of magnesium and other macrominerals in sheep infused with potassium in different parts of the digestive tract

Two metabolism trials were conducted with 12 crossbred wether lambs, each surgically equipped with a ruminal catheter and abomasal and ileal cannulae, to study the effect of K infusion in different sites of the digestive tract on site of absorption and flow of minerals. The treatments consisted of the infusion of 33.6, 12.0 or 12.0 g K/d as bicarbonate into either the rumen, abomasum or ileum, respectively. Each trial consisted of a minimum 5-d preliminary period, five 3-d collection periods to determine mineral balance and a 6-d sampling period to determine mineral flow and site of absorption. Chromic oxide was incorporated into the diet for use as a marker. Magnesium was absorbed primarily from the preintestinal region. Ruminal infusion of K tended to decrease preintestinal Mg absorption. Absorption of Mg in the entire tract was decreased (P less than .05) 43% when K was infused into the rumen. There was a slight absorption of Mg in the small intestine, followed by a net secretion into the large intestine. Serum Mg levels tended to be depressed in lambs infused with K intraruminally. Calcium flow from the preintestinal region was decreased (P less than .05) by infusion of K into the rumen. Only lambs infused with K in the rumen had a net secretion of Na into the small intestine. The large intestine was the primary site of net Na absorption for ruminal-infused lambs. Phosphorus flow from the preintestinal region was decreased (P less than .05) by infusion of K into the rumen. Potassium flow from both the preintestine and small intestine was increased (P less than .05) by ruminal K infusion. The infusion of K into the rumen, abomasum or ileum increased (P less than .05) the total absorption of K, with the small intestine being the major absorptive site. The infusion of potassium bicarbonate into the rumen of sheep raised (P less than .05) the pH of the ruminal contents 15%. Ruminal infusion of K depresses Mg absorption, while the infusion of K into the abomasum or ileum does not affect Mg absorption. Therefore, the role of K in grass tetany may be via this depression of Mg absorption.     

Actinomycosis of the digestive tract in cattle

Extract

The following is the history of actinomycosis in a beef herd of approximately 400 Hereford Cross BlackPoll steers of average age about 3 ½ to 4 years, over a period of 14 months, during which time some 16 cases of actinomycosis-like infections have occurred.     

沙葱提取物对绵羊消化道乳酸菌产共轭亚油酸(CLA)含量的影响

本文选择了4只瘘管蒙古羯羊,通过在绵羊日粮中添加沙葱提取物,采集瘤胃液和食糜,分离和筛选乳酸菌,添加亚油酸培养来研究沙葱提取物对绵羊消化道乳酸菌产共轭亚油酸(CLA)含量的影响。结果表明,沙葱提取物显著提高绵羊瘤胃和十二指肠中乳酸菌的数量和CLA的含量,且十二指肠中的大于瘤胃中的。这为进一步调控绵羊瘤胃内环境,提高羊肉中CLA含量打下基础。     

绵羊消化道永久性三位点瘘管手术的体会

反刍家畜消化道的“三位点”瘘管装置,包括瘤胃瘘管、十二指肠近端瘘管、回肠末端瘘管,是研究反刍动物营养代谢最直接有效的手段。因科研需要.笔者于2005年5月对天津市农业科学院反刍动物营养研究室5只12月龄、体重35~40 kg的绵羊,实施了消化道的“三位点”永久性人造瘘管手术。手术后瘘管伤口愈合良好,瘘管都能正常使用并保持到10个月以上。1术前准备1.1术羊准备手术羊术前禁食24 h,麻醉采用速眠新2号(解放军军事医学科学院兽医研究所研制),肌肉注射,剂量为0.01 mL/kg体重,注射后5~7 min即可进入手术3级麻醉状态。1.2药械准备1.2.1手术器…     

Effect of feeding pelleted feed on the level of volatile fatty acids in the digestive tract of sheep]

In an experiment with wethers we investigated the effect of complete pelleted feed ration on the concentration of volatile fatty acids in the rumen and intestinal tract. The animals consumed daily 1,300 g of dry matter of a diet which contained 41.81% of meadow hay, 25.28% of barley, 15.37% of sawdust, 14.98% of molasses, 1.32% of urea and 1.24% of a vitamin-mineral supplement for a period of six months. The pelleted diet increased the total amount of volatile fatty acids, the content of propionic acid and especially the content of butyric acid. There appeared a decrease in the ratio of acetate: propionate. On the basis of the greater energy efficiency of the volatile fatty acid production the animals fed pelleted feed showed a better energy balance. A higher VFA concentration was determined also in the large intestine and the cecum, which proves the importance of fermentation porcesses in these organs.     

Efficacy of an Arthrobotrys oligospora N mutant in nematode-trapping larvae after passage through the digestive tract of sheep

For oral applications, biocontrol of animal parasitic nematodes in ruminants, ion beam implanted nematode-trapping fungi must have the capacity to survive the passage through the digestive tract and be efficient in reducing infective larvae of nematodes in the faeces.Ion beams induced mutation in the spores of nematode-trapping Arthrobotrys oligospora. Mutants with genetic stability were bred. The fungi were cultured in bottles with corn kernels as growth media, and spores of different doses were, respectively, administered orally to each group of sheep naturally infected with gastrointestinal nematodes. The control group did not receive fungi. The faeces of these experimental animals were collected and faecal cultivations carried out. The fungal germination, growth, reproduction and predation of livestock parasitic nematode larvae were tested in laboratory. The efficacy of an A. oligospora N mutant in nematode-trapping larvae after passage through the digestive tract of sheep was tested. The results indicated that the ion beam implantation induced mutation of the nematode-trapping fungi is a positive mutation. The mutant spores through the digestive tract of sheep can kill livestock parasite nematode larvae in vitro. These results indicate the potential of the A. oligospora N mutant as a biological control agent for sheep nematodes.This study showed that such biotechnology could be explored for improving the effectiveness of the use of fungal infections to control livestock parasitic nematodes. This work represents the first application of nematode-trapping fungi in eukaryotic microorganisms.     

Estimation of uptake of digestive tract strongyle larvae from pasture, using oesophagus fistulated sheep

Three Merino of Arles ewes fistulated at the oesophagus were used in autumn and spring in order to assess their larval uptake on infected irrigated pasture. The rate of transmission (ingested/available larvae of digestive tract strongyle) was low when the pasture was heavily infected; it was not otherwise modified by environmental factors.