The duration of lot-feeding of sheep before sea transport

Adult wethers (n = 750) were lot-fed for 13 days, 8 days or 3 days before a simulated voyage lasting 18 days to examine whether the period of lot-feeding affected the proportion of sheep that ate pelleted feed and their body weight change during simulated shipping. There was no significant difference in the proportion of non-feeders between treatment groups on days 7 and 14 of the voyage. Body weights were not significantly different between the treatment groups on days 14 and 18 of the voyage. Overall body weight loss, from the farm to the end of simulated shipping, was 4.08 kg (+/- 0.28, s.e.m.), 4.58 kg (+/- 0.28) and 4.51 kg (+/- 0.28) in sheep lot-fed for 13 days, 8 days and 3 days, respectively, and was not significantly different between treatments. It was concluded that lot-feeding for 13 days conferred no advantage in body weight or numbers of non-feeders compared with shorter periods in this study.     

Effects of Confluent, Roscovitine Treatment and Serum Starvation on the Cell-cycle Synchronization of Bovine Foetal Fibroblasts

The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors.     

Isolation of Bartonella henselae from a serologically negative cat in Bloemfontein, South Africa

Sera collected from apparently healthy 6-12-month-old cats (n = 31) presented to the Society for the Prevention of Cruelty to Animals Veterinary Clinic in Bloemfontein for neutering were tested for antibodies reactive to Bartonella henselae (Houston-1 strain) by indirect fluorescent antibody testing. Whole blood collected from the cats was used in isolation experiments and subsequent identification of Bartonella species was based on comparison of the nucleotide base sequence of polymerase chain reaction-amplified citrate synthase gene fragments. While none of the cats had antibodies reactive with B. henselae at titres > or =1/64, an organism with a partial citrate synthase gene sequence identical to that of B. henselae (Houston-1) was isolated from 1 cat.     

The breed prevalence of dog erythrocyte antigen 1.1 in the Onderstepoort area of South Africa and its significance in selection of canine blood donors

The blood group antigen Dog Erythrocyte Antigen (DEA) 1.1 is clinically the most important canine blood group as DEA 1.1 antibodies are capable of causing acute haemolytic, potentially life-threatening transfusion reactions. Dogs do not have naturally occurring antibodies to DEA 1.1 but are rapidly sensitised by the first incompatible transfusion. The prevalence of DEA 1.1 in the general dog population is estimated at 42-46%. Canine blood donors registered with the Onderstepoort Animal Blood Bank (n = 93) as well as potential donors (n = 140) were typed for DEA 1.1 using a monoclonal antibody card kit. All dogs came from the Onderstepoort area, near Pretoria, Gauteng province, South Africa. Overall prevalence of DEA 1.1 was 47%. Prevalence was 47% in purebred dogs and 48% in mongrels. Distinct breed differences were noted with less than 20% of German shepherd dogs and Boxers and greater than 75% of Rottweilers, Great Danes, St Bernards and Dalmations testing DEA 1.1 positive. Knowledge of local breed differences will increase effectiveness of blood donor recruitment.     

Management of inappetant sheep during export by sea

In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS)     

Monensin controlled-release intraruminal capsule for control of bloat in pastured dairy cows

Monensin, a polyether ionophore antibiotic, is potentially an important agent for bloat relief in dairy cows grazing temperate legume-based pasture. A series of studies was undertaken to determine the effect of monensin, when delivered continuously in the rumen of lactating dairy cows by means of controlled-release capsules (monensin CRC). Such devices release approximately 300 mg/head/day for 100 d. A short-term pilot study made at Ruakura, New Zealand, tested monensin CRC in cows selected for high susceptibility to bloat and grazing lucerne (Medicago sativa) or red clover (Trifolium pratense). Treatment significantly reduced the incidence of bloat, while milk yield and protein yield were increased. There was no effect on fat yield. Following the pilot study, 6 large-scale field experiments involving a total of 368 lactating dairy cows, were made in Australia and New Zealand to confirm the effectiveness of monensin CRC for bloat control and to measure the effect of such treatment on milk production and composition. A severe bloat problem occurred in 2 experiments, mild bloat occurred in 2 others, while no visual signs of bloat were observed in the remaining 2 experiments. Bloat was significantly (P less than 0.05) reduced by monensin CRC treatment when data was pooled over the 4 experiments in which bloat occurred. Daily milk yield was increased in all experiments from a mean of 17.7 in untreated groups to 18.8 kg/head/day (P less than 0.05) in monensin CRC-treated cows. Protein percentage was not affected by treatment, while there was a decrease from 4.29 to 4.10% fat, although total fat yield was not affected.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chromosome locations of leaf rust resistance genes in selected tetraploid wheats through substitution lines

Langdon durum D-genome disomic substitution lines were used to study the chromosome locations of adult-plant leaf rust resistance genes identified from tetraploid wheat accessions. The accessions are 104 (Triticum turgidum subsp. dicoccum var. arras) and 127 (T. turgidum subsp. durum var. aestivum). The complete sets of the substitution lines were crossed as female parents with the accessions and F₁ double monosomic individuals selected at metaphase I. Segregating F₂ individuals were inoculated during the flag leaf stage with pathotype UVPrt2 of Puccinia triticina. The substitution analysis involving accession 104 showed that the gene for leaf rust resistance is located on chromosome 6B. The analysis with accession 127 indicated that chromosome 4A carries a gene for leaf rust resistance. The two novel genes are temporarily designated as Lrac104 and Lrac127, respectively from accessions 104 and 127.     

An application of the mixed linear model and the dirichlet process prior in veterinary medicine research

This article applies Bayesian nonparametric techniques of analysis to the mixed linear model. The distribution of the random effects is specific as a nonparametric prior. A Dirichlet process prior is specified on the space of prior distributions. A modified Dirichlet process is described and applied using a Gibbs sampler. The approach is demonstrated in an investigation of the changes over time of packed cell volume in two breeds of cattle.