Clinical, clinicopathologic, pathologic, and toxicologic alterations associated with gossypol toxicosis in feeder lambs

The toxicity of gossypol was studied in 20, 8-week-old feeder lambs that weighed approximately 16 kg. The lambs were allotted to 4 groups (A, B, C, D) and given (orally for 30 days) a daily dosage of gossypol (0, 45, 136, or 409 mg, respectively). Lambs were observed twice daily until they died or were euthanatized on the day the last dose was given. Clinical, electrocardiographic, clinicopathologic, pathologic, and toxicologic findings were recorded. All lambs given 409 mg of gossypol (group D) died before the end of the 30-day study. In this group, clinical signs included sudden death and/or chronic dyspnea syndromes. One group-B lamb had chronic dyspnea, but did not die. Electrocardiographic abnormalities observed in gossypol-treated lambs included increased amplitude of the T wave and decreased duration of the ST segment. Clinicopathologic alterations in group-D lambs included high serum total lactate dehydrogenase and lactate dehydrogenase liver-specific isoenzyme activities. Serum total creatine kinase activity decreased markedly in lambs of all groups treated with gossypol. Hemoglobinuria was detected in 2 group-D lambs. The average daily weight gain was remarkably consistent in lambs of all groups, except in 1 lamb each of groups D and B. Lambs were necropsied when they died or on day 30 of the study. The heart of gossypol-treated lambs weighted more than did that of untreated (control group A) lambs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evidence for an immunocompromising effect of bovine pestivirus on bovid herpesvirus 1 vaccination

Five calves were given live intranasal vaccine against bovid herpesvirus 1 (BHV1) two days after intranasal inoculation of bovine pestivirus (BVDV). Another 5 were vaccinated in the absence of BVDV. Control unvaccinated groups were also maintained. All calves were challenged with virulent BHV1. The unvaccinated calves developed signs of infectious bovine rhinotracheitis (IBR) and both vaccinated groups showed a similar degree of clinical protection from IBR. Those given BVDV before vaccination shed up to 140 times more BHV1 (P less than 0.01) in the nasal mucus following challenge than those which had received BHV1 vaccine alone. The epidemiological significance of this is discussed.     

Proliferative haemorrhagic enteropathy in pigs.

An outbreak of proliferative haemorrhagic enteropathy (PHE) occurred in two epidodes and affected 372 adult pigs in the breeding units of a minimal disease piggery; 186 pigs died. In the initial episode breeding sows and boars of all ages were affected, suggesting infection of a fully susceptible population. Animals involved in the first episode of the disease did not show clinical symptoms at a later date and further clinical cases occurred only in animals introduced into the breeding population. Antibiotic feed medication was an effective method of prophylaxis. Bacteria resembling Campylobacter sputorum subspecies mucosalis were isolated from the intestinal mucosa of affected animals.     

The welfare of finishing pigs in two contrasting housing systems: Fully-slatted versus straw-bedded accommodation

Four consecutive studies were carried out over a 3-year period to assess the health and welfare implications of housing finishing pigs in either fully-slatted or straw-bedded accommodation. In each study, 1024 (Large White × Landrace) × Large White pigs, housed in pen groups of 32, were fed ad libitum from 34 kg to slaughter at 104 kg live weight. Eight batches of pigs were received in each study and allocated alternately to fill one room of four pens in each house. Data were collected on a range of welfare parameters. Lameness (P < 0.001) and bitten tails (P < 0.001) were more prevalent health problems in the fully-slatted system, whilst in the straw-bedded system pigs showed more respiratory (P < 0.01) and PMWS-type symptoms (P < 0.01). Acute phase protein titres at slaughter were higher in pigs from the fully-slatted system (P < 0.001). Skin lesion score did not differ between systems; however, bursitis was more severe in pigs in the fully-slatted system (P < 0.001). Pigs in the straw-bedded system had poorer hygiene scores (P < 0.001), but the magnitude of this difference varied between studies depending on season. Pigs with straw were more active (P < 0.001), spending a large proportion of time manipulating straw. In the absence of straw, pigs spent more time in behaviour directed at other pigs (P < 0.001) and the pen components (P < 0.001). Post-slaughter assessment showed no system differences in lung lesions and cardiac scores, or osteochondrosis. Pigs with straw had more severe toe erosions on the foot (P < 0.001), whilst pigs without straw had more severe sole (P < 0.001) and heel erosions (P < 0.001). Gastric lesion scores were lower in the fully-slatted system (P < 0.001). The results show both advantages and disadvantages to each of the housing systems for pig welfare.