The interbreeding of sheep and goats.

To determine the outcome of interbreeding sheep and goats, ewes and does were bred to rams and bucks, and their embryos recovered. Pregnancy was monitored in 2 does bred to a ram. Fertilization rates in ram X does, buck X does, ram X ewes, and buck X ewes were 72%, 96%, 90%, and 0%, respectively. Ram X doe fetuses died at 5 to 10 weeks.     

Ruminal lactic acidosis in sheep and goats.

The clinical findings in 37 sheep and goats with acute ruminal lactic acidosis included a disturbed general condition characterised by anorexia, apathy, teeth grinding and muscle twitching, ruminal stasis, and the excretion of soupy or watery faeces. The ruminal fluid of affected animals was milky, had a sour odour and a low pH. There was a predominance of Gram-positive bacteria in smears of ruminal fluid. In comparison with 10 control animals, the rumen fluid of 23 sheep with ruminal lactic acidosis had higher lactic acid and lower volatile fatty acid concentrations. In addition, the affected animals often had haemoconcentration and metabolic acidosis. Treatment included single or repeated transfer of ruminal fluid from healthy cows and, depending on the severity, the administration of antacids, yeast and chlortetracycline, and the intravenous infusion of isotonic sodium chloride and 5 per cent sodium bicarbonate solutions. Of the 37 treated sheep and goats, four died within 24 hours, and three others were euthanased after one, two and three days because their condition rapidly deteriorated. Thirty animals were discharged one to nine days after treatment. Twenty-nine of them (78.4 per cent) recovered completely but one was euthanased later.     

Necropsy of sheep and goats

In this article, diseases will be discussed by system. Common differential diagnoses that may be associated with gross lesions are pointed out, and practical laboratory tests are presented that may help establish a specific diagnosis.     

Clinical nutrition of sheep and goats

Management systems and client goals are integral components of clinical nutrition and vary among and within sheep and goat producers. Evaluation includes client interview and history taking, record examination, forage analyses, animal examination, and occasionally blood or tissue assays. The types of nutritional disorders that are likely to be observed in sheep and goats vary according to the type of management and can be grouped according to feedlot, intensive production, farm flocks, dairy, and browse systems. Examples described include nutritional problems that may be overlooked (water deprivation), widespread (energy imbalance), currently difficult to prevent and treat (selenium deficiency), and reflective of soil-plant-animal complexities (copper-molybdenum balance).     

Genetic diseases of sheep and goats

Congenital malformations and inherited disorders constitute a substantial proportion of the afflictions seen in sheep and goats. Of these, malformations tend to be similar in both species, whereas the genetic diseases encountered to date, with the exception of a few, are different. Of the 28 genetic diseases of sheep and goats described in this review, 60% and 62.5%, respectively, are monogenic disorders. For a majority of the monogenic recessive disorders encountered in these species, the carrier state is not detectable at present, whereas in others, in which a biochemical lesion is known (dermatosparaxis, erythrocyte glutathione deficiency, globoid cell leukodystrophy and glycogen storage disease), the carrier state is detectable with the aid of enzyme and surface protein markers. The latter group and the dominant disorders (anury, cataract, glomerulonephritis, and lethal grey in sheep; gynecomastia and anotia-microtia complex in goats) are easy to eliminate through selective breeding. The polygenic disorders (entropion, epidermolysis bullosa, hereditary chondrodysplasia, and muscular dystrophy of sheep, and udder problems in goats) are more difficult to eradicate, because the mutant genes responsible for these traits generally do not declare themselves until inbreeding brings together a critical concentration to create a health crisis in some, whereas others, which are only short of a few of these mutant genes, might go totally unaffected and therefore undetected. Chromosome defects of the structural nature (translocations) seen in sheep and goats generally create meiotic disturbances, which in a majority of cases lead to subfertility, whereas sex chromosome aneuploids are generally sterile.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anesthesia techniques in sheep and goats

A variety of techniques can be used to anesthetize and restrain sheep and goats safely and humanely both in the clinic and in the field. The use of inhalational, injectable, and local anesthetic agents is discussed. Nontraditional agents (opioids and alpha-2 adrenergic agonists) for epidural analgesia also are reviewed because of their promising clinical application.     

Sawfly poisoning in sheep and goats

In September 1984 some sheep in a flock of 250 suffered depression, anorexia, incoordination and difficulty in rising; 50 ewes and weaners died. Post mortem examination revealed petechial bleeding, massive acute liver necrosis and in some animals degeneration of the kidney tubules. The rumen and gut contained many larvae of the blue-black birch sawfly (Arge pullata). Laboratory and field observations indicated that these were the cause of the illness.     

羊球虫病的研究进展

羊球虫病是由艾美耳属球虫引起的一种呈世界性分布的肠道原虫病,能引起羊腹泻、渐进性消瘦、贫血、发育不良,甚至发生死亡,羔羊发病率和死亡率较高,给山羊生产业和绵羊生产业造成巨大的经济损失。本文就羊球虫病的病原种类、流行病学特点、临床症状和病理变化、诊断、防治等方面的研究进展进行了综述。