Effect of season and supplementation on percentage live sperm and sperm abnormalities in Horro (Zebu) bulls in sub-humid environment in Ethiopia.

A total of 32 Horro (Bos indicus) bulls, with an average initial body weight and age of approximately 211 kg and 6 years were evaluated. The bulls were divided into two treatment groups. One group was given a supplementary concentrate at a rate of 1.5 kg/day and the second group served as the control and received no supplementation. The observation period lasted for 50 weeks. Semen was collected every two weeks by mean of electrical stimulation with the aid of an electro-ejaculator. The percentage of abnormal sperm (total abnormalities, head, midpiece and tail) remained lower in the supplemented group than in the non-supplemented group. The percentage of live sperm tended to be higher in the supplemented group throughout the 50-week trial period. Until week 17 of the trial there were no significant differences; however, starting at week 18 there were significant differences between the two treatment groups except for week 26. Thereafter, significant differences were recorded until week 38; from week 40 no significant differences were observed between the two groups in respect of percentage of live sperm (except for week 48). Season (week) during which the semen samples were collected had no significant effect on the percentage of abnormal sperm in both treatment groups (supplemented and non-supplemented). At the start of the trial the nutritionally supplemented group had a higher occurrence of sperm abnormalities (11.4% +/- 1.1%) compared to 8.3% +/- 1.3% in the control group. Thereafter, sperm abnormalities declined rapidly in the supplemented group (except for week 50). The sperm abnormalities for the non-supplemented group showed a tendency to increase during the entire observation period.

The effect of supplementation on productive performance of Boer goat bucks fed winter veld hay.

Fifteen Boer goat bucks, (6-8 months old), were allocated into two groups and fed ad libitum for a period of 29 days. The WH group (winter hay; n = 8) received a chopped diet consisting of grass hay, predominantly Themeda trianda grass (cut during the winter) from a natural pasture (veld). The WH+S group (winter hay plus supplement; n = 7) received a chopped diet consisting of Themeda trianda veld hay, supplemented with maize meal, molasses meal and urea. Body weights and feed consumption were recorded. Animals were slaughtered and carcass characteristics (weight and percentages of selected carcass cuts) and the carcass chemical composition were determined. The WH+S animals showed a higher live weight and cumulated feed intake. Carcass cuts from WH animals represented a higher percentage of the total carcass, especially cuts where muscle depots are higher (legs, best end chops and prime cuts). There is an attempt by non-supplemented animals to preserve the body's nitrogen reserves under prolonged nutritional stress conditions, and there is consequently a necessity to supplement feeding of small ruminants fed winter veld hay, especially if the animals are to be used in subsequent breeding seasons.

A study to evaluate the field efficacy of ivermectin, fenbendazole and pyrantel pamoate, with preliminary observations on the efficacy of doramectin, as anthelmintics in horses.

The efficacy of ivermectin, fenbendazole, pyrantel pamoate and doramectin was evaluated under field conditions at 2 sites in the Free State Province of South Africa. The study involved 25 horses at each site, divided into 5 groups of equal size. Ivermectin, fenbendazole and pyrantel pamoate were administered orally at doses of 0.2, 10 and 19 mg/kg respectively. Doramectin was administered by intramuscular injection at a dose of 0.2 mg/kg. Treatment efficacy was based on the mean faecal egg count reduction 14 days post treatment. At site A a faecal egg count reduction of 100% was found after treatment with ivermectin, fenbendazole and doramectin. A 96.1% reduction was found after treatment with pyrantel pamoate. At site B ivermectin and doramectin produced a 100% reduction in faecal egg counts, fenbendazole produced an 80.8% reduction and pyrantel pamoate a 94.1% reduction. Doramectin produced a 100% reduction in faecal egg counts at both sites, despite not being registered for use in horses. In addition, the results indicated reduced efficacy of fenbendazole at site B, which suggested benzimidazole resistance. Larval cultures showed that cyathostomes accounted for between 86 and 96% of pre-treatment parasite burdens at both sites. Other helminths identified in the faecal samples were Strongylus spp. and Trichostrongylus axei.