Alterations of selected intestinal enzymes in hamsters with hamster enteritis syndrome.

Portions of duodenum, jejunum, and ileum from 21 hamsters clinically affected with enteritis were examined for enzymes. Utilizing a variety of techniques, the activities of alkaline phosphatase, nonspecific esterases, leucine aminopeptidase, beta-glucuronidase, and methyl green pyroninophilia were determined. The activities of enzymes normally associated with tissue proliferation and active protein synthesis were decreased, whereas those enzymes associated by cytolysis were increased.     

Anticoccidial Vaccination of Broiler Chickens in Various Management Programmes: Relationship between Oocyst Accumulation in Litter and the Development of Protective Immunity

Paracox anticoccidial vaccine was administered to a 7-day-old flock of commercial broiler breeder stock subsequently reared to point-of-lay in the same house. For comparison, three subgroups of another flock of broiler breeders were also vaccinated with Paracox at 7 days of age, reared to 42 days and then transferred to new litter on another farm until point-of-lay. The first subgroup received no further treatment, but the second and third each received a second vaccination with Paracox, either immediately after transfer to the new litter or 42 days after transfer. Using an Eimeria necatrix model, protective immunity was demonstrated by virulent challenge of samples of birds from all groups by the age of 37–40 days (30–33 days after the first vaccination), and was maintained to at least 122–125 days of age, whether the birds remained on the same litter or were transferred to another farm, and whether they received one or two anticoccidial vaccinations. Therefore, there is no disadvantage in transferring birds onto new litter 35 days after a single Paracox vaccination, nor is there any advantage in giving a second vaccination after such a transfer. Vaccinated birds seeded the new litter with oocysts, despite being clinically immune to coccidiosis. A supplementary laboratory experiment showed that birds vaccinated at 8 days of age passed almost no oocysts after a second vaccination at 43 days of age. This indicated that they were not only protected against clinical coccidiosis, but were almost solidly immune to a homologous infection 5 weeks after a single vaccination. Nevertheless, oocysts appeared in the litter of all four groups of commercial breeders throughout the trial, showing that wild-type heterologous infections occurred whether the birds were transferred to new litter or not, but these did not overwhelm the acquired protective immunity and cause clinical coccidiosis.     

Comparative growth performance of pigs immunised with a gonadotrophin releasing factor vaccine with surgically castrated pigs and entire boars raised under conventionally managed conditions

The objective of this study was to determine the effect of using a gonadotrophin releasing factor (GnRF) vaccine on growth performance of male pigs. Vaccinated pigs were compared with surgically castrated pigs and entire males under conventionally managed farm conditions. Male pigs were randomly assigned to three treatment groups: pigs surgically castrated during the first week of life (group "C", n=274), pigs immunised twice during the fattening period with a GnRF vaccine, the first when 13-14 weeks of age and the second when 20-21 weeks of age (group "V" n=280) and entire males (group "E", n=56). Average daily weight gain (ADG) was measured during the study. Additionally, feed conversion ratio (FCR) as defined by feed intake/weight gain and feed consumption was assessed during the fattening period. No difference in the ADG during the fattening period could be determined between "C" and "V". From the start of the study until slaughter at study day 160/173 the ADG in group "E" was lower (625 g/day; P) than in group "C" (681 g/day; P < 0.001) and group "V" (675 g/day; P < 0.01). The FCR during the fattening period until study day 160, three days before the first batch of pigs were slaughtered at 24-25 weeks of age, was higher in group"C" (2.72 kg feed intake/kg weight gain) compared with group "V" (2.44 kg feed intake/kg weight gain; P < 0.001) and group "E" (2.44 kg feed intake/kg weight gain; P <0.01). Pigs in group "V" performed similarly to those in group "E" until the second vaccination (day 135) after which time they showed a substantial increase in feed intake and ADG, while retaining an FCR advantage over group C.     

Leptospirosis in selected wild mammals of the Florida panhandle and southwestern Georgia.

A group of 144 wild mammals, including white-tailed deer, cottontail rabbits, fox squirrels, gray squirrels, raccoons, opossums, a bobcat, and various small rodents was examined for cultural or serologic evidence of leptospiral infection. Leptospires were isolated from 1 of 25 rabbits, 1 of 27 fox squirrels, 1 of 26 gray squirrels, 4 of 18 mice and rats, 8 of 21 raccoons, 7 of 17 opossums, and a bobcat. Isolations were not made from 6 deer examined. Serotypes isolated were Leptospira interrogans, serotype grippotyphosa and L interrogans, serotype ballum. New host-serotype relationships were noticed in the following instances: bobcat: grippotyphosa, and gray squirrel: ballum. These studies further confirm the occurrence of grippotyphosa in the fox squirrel. Serologic response in these animals did not necessarily correlate with isolations, although some relationship was noticed in raccoons and opossums.     

An outbreak of ringworm in a group of young cattle.

In an outbreak of ringworm, 30 out of 32 bull calves being reared intensively for beef showed infection. Weekly observations were made from their arrival at the farm at about one week old until slaughter at approximately 10 1/2 to 12 months of age. The outbreak lasted for 33 weeks and appeared to originate from two animals brought into the unit. Lesions occurred first, and most commonly, in the head region. The disease in individual animals lasted eight weeks and each lesion had a mean duration of 3.6 weeks. New lesions occurred after those elsewhere on the same animal had healed. The mean incubation period was estimated at 4.6 weeks. Spread of ringworm was probably mainly due to the licking and grooming activities of the calves' tongues.     

The effect of phenothiazine on cobalt-deficient and cobalt-dosed lambs

The mean serum folate concentrations of Large White sows were compared between one group of 13 animals, 43–80 days pregnant and another group of 9 animals at weaning when the litters were 28–30 days old. The mean concentration was higher in sows at weaning (p<0.05) and the lowest levels were found in sows no more than 51 days pregnant (p<0.05).