Efficacy of avermectin B1 given orally against equine intestinal strongyles and Onchocera microfilaria

Three groups of horses and ponies (N = 13, 13 and 12) were treated with ivermectin paste (0.2 mg/kg p.o.), avermectin B1 solution (0.2 mg/kg p.o.), or fenbendazole suspension (10 mg/kg via nasogastric tube). The avermectin B1 was a 1% solution in a propylene glycolglycerol formal base. Faecal strongyle egg counts were performed before, and 14, 28, 42, 56 and 70 d, after treatment. Full-thickness skin biopsies from the neck, pectoral and umbilical regions were examined for Onchocera microfilaria before treatment, and again 14 and 70 d later. Ivermectin therapy produced a significant (P less than 0.01) decrease in mean strongyle egg counts 14, 28, 42 and 56 d after treatment. Avermectin B1 therapy resulted in significant (P less than 0.01) decreases in mean strongyle egg counts 14, 28 and 42 d after treatment. All horses given ivermectin or avermectin B1 had zero strongyle egg counts 14 and 28 d after treatment. Fenbendazole failed to significantly decrease strongyle egg counts. Both ivermectin and avermectin B1 resulted in zero microfilaria counts in all horses 14 d after treatment. On day 70 the percentage decrease in microfilaria counts were 100% and 99.6% respectively. Fenbendazole failed to significantly decrease microfilaria counts. The oral administration of this formulation of avermectin B1 appeared to be highly efficacious against intestinal strongyles and Onchocera microfilaria. The duration of anti-strongyle activity was, however, significantly (P less than 0.01) shorter than that of ivermectin paste.     

Surgical resection of a dysgerminoma in a mare

A mare was referred for further evaluation of a mass found in the left caudal abdomen during a routine postpartum reproductive palpation. The mare was clinically normal with no history of health problems. Ultrasonographic examination of the mass confirmed its presence, but the origin of the mass could not be accurately determined. Routine haematology and serum biochemistry results were within normal limits. The mare was initially treated conservatively with antibiotics, but the mass continued to increase in size, so it was surgically excised. The mass involved the left ovary. The mare showed transient abdominal pain after surgery, but developed no other complications and was in foal 7 months later. On histology, the mass was diagnosed as a dysgerminoma, a rare ovarian tumour of germ cell origin.     

Ileal and total tract digestibility in local (Mong Cai) and exotic (Landrace × Yorkshire) piglets fed low and high-fibre diets, with or without enzyme supplementation

Ileal and total tract digestibility of low and high-fibre diets (100 and 200 g/kg neutral detergent fibre), with or without enzyme supplementation (mixture of cellulase, β-glucanase, α-amylase and protease) was determined in piglets of two breeds weaned at 30 days of age. The breeds were local (pure-breed Mong Cai, MC) and exotic (Landrace × Yorkshire, LY). The experimental diets were based on maize meal, soybean meal, fish meal, cassava residue meal, and rice bran. Cassava residue meal and rice bran were the main fibrous feeds in the high-fibre diet. The experiment was arranged according to a 2 × 2 × 2 factorial, completely randomized design with 4 replications, and lasted for 30 days. The coefficient of ileal apparent digestibility (CIAD) was measured by analyzing ileal digesta collected from piglets killed at 60 days of age. The coefficient of total tract apparent digestibility (CTTAD) was measured by analyzing faecal samples collected for 5 consecutive days immediately before the experiment finished. The CIAD and CTTAD of organic matter, crude protein, crude fibre, neutral detergent fibre, acid detergent fibre and amino acids in the high-fibre diet were lower than in the low-fibre diet (P < 0.01). The CIAD of nutrients and amino acids was similar (P > 0.05) between MC and LY, while the CTTAD of nutrients was higher for the MC than for LY (P < 0.05). Enzyme supplementation of the high-fibre diet improved daily gain and the digestibility of all dietary components at the ileum and in the total tract (P < 0.05), but there was no effect of enzyme supplementation of the low-fibre diet (P > 0.05).     

The phenotypic characteristics and relational database for Vietnamese native pig populations

Although there are a number of Vietnamese native pig (VnP) populations, some are on the verge of extinction, and therefore adequate management and conservation are necessary. In this study, we conducted a field survey of VnP populations and analyzed interrelationships among their characteristics. We also established a relational database for management of field data on these populations. For data collection, we conducted interviews with farmers and visual inspection of 32 VnP populations in 22 provinces of Vietnam, as well as taking photographs of individual animals. Data on the characteristics of VnP populations were subjected to multiple correspondence analysis (MCA). For establishment of the database, normalization and table partitioning were performed to eliminate redundancy and ensure consistency of the collected data items. Passport data, characteristics data, and image data were collected from a total of 1,918 VnPs and entered as a normalized table. Upon MCA, most of the populations were not separated from each other, but the Mong Cai, O Lam, and Chu Prong populations were separated from the other populations. Thus, we have constructed a relational database from comprehensive information on the characteristics of VnP populations.     

Reproductive performance in South Australian dairy herds

SUMMARY Herd breeding records (161) were examined from a random 10% sample of dairy farms (96) in South Australia with more than 40 cows and suitable breeding records for 1988 and/or 1989. Of these farms, 53 (55.2%) had a year-round calving pattern, 42 (43.8%) claimed to be seasonal and one was changing from a year-round to a seasonal pattern. Only 14.6% of farmers observed oestrous behaviour outside milking times and 18.8% used tailpaint. Overall, the average proportion of unobserved heats was estimated to be 32%. Artificial insemination (AI) was carried out on 85.4% of farms (16.7% used AI alone and 68.7% also used bulls) of which 32.9% used commercial technicians and 67.1% were do-it-yourself operators. Overall, the average 30-day submission rate was 59.9% and the average 49-day non-return to service rate was 58.9%. Investigation into the probable causes of suboptimal reproductive performance gave a tentative diagnosis of inefficient oestrous detection, deferral of service, inadequate nutrition, poor AI technique, insufficient bulls, and venereal/other diseases in 69.1, 32.1, 27.2, 28.4, 13.6 and 7.4% of records, respectively.