The effect of parenteral supplementation of vitamin E with selenium on the health and productivity of dairy cattle in the UK

Recent work has suggested that the recommended intakes of vitamin E for dairy cattle need to be increased, particularly in dry cows. However, these suggestions are based on data from cattle in the USA, which may have significantly different oxidative stresses than European cattle. This study, which involved 594 cattle on three dairy farms, was designed to determine the effect of increased vitamin E supplementation on the health and fertility of UK dairy cows. Cattle were randomly allocated to receive either two intramuscular injections of 2100 mg of vitamin E (and 7 g of sodium selenite) 2 weeks before calving and on the day of calving, or no additional vitamin E supplementation. Although supplementation had no effect on milk yield, reproductive efficiency, or incidence of uterine infections, supplemented cattle had a lower risk of culling and a lower rate of mastitis. These figures were economically significant but not statistically significant at the 10% level. Supplementation reduced the incidence of retained fetal membranes from 6.5% to 3%, an effect which was almost significant at the 5% level. If these data are representative they suggest that vitamin E recommendations for UK cattle should be reassessed.     

The chimpanzee as an animal model for investigating alcoholism

Young chimpanzees (Pan troglodytes) will accept ethanol in quantities sufficient to produce symptoms of withdrawal when ethanol is subsequently discontinued. Mild to severe symptoms of physical dependence, including grand mal seizures, are observed when ethanol is abruptly withdrawn after 6 to 10 weeks of chronic oral intake. In addition, the rate of disappearance of ethanol in blood increased during periods of chronic ingestion, an indication of developing metabolic tolerance. These results suggest that the young chimpanzee may be a suitable model for experimental studies of alcoholism.     

The application of bioelectrical impedance analysis in live tropical hair sheep as a predictor of body composition upon slaughter

Animal management for breeding and marketing can be improved by precise measurement of desirable traits. Live animal body composition analysis facilitates the selection of animals that are best suited for the intended purpose. This study was designed to assess the accuracy of bioelectrical impedance analysis (BIA) predicted live body tissue composition, as a proxy for the estimation of carcass quality in Barbados Black Belly lambs. Thirty-four Barbados Black Belly lambs were placed on an 8-week feeding regime and then slaughtered. A randomized experimental design was used to allocate diets to animals, which had been stratified into eight groups by initial live weight. The lambs were fed a basal diet of Brachiaria arrecta fresh forage ad libitum and subjected to one of four diets; NS—non-supplemented diet, TG—Trichantera gigantea-supplemented, C100—concentrate supplemented for maintenance, and C400—concentrate supplemented for growth. Diets NS, TG, C100, and C400 had 7, 9, 11, and 7 animals, respectively. The average age and weight at the time of slaughter were 206 days and 23.7 kg, respectively. A 4-terminal impedance analyzer (RJL Systems®) was used to generate BIA data from live animals immediately before slaughter. The chilled carcasses were then subject to chemical analysis for crude fat, crude protein, and dry matter. Live animal and carcass traits predicted by BIA included fat and fat-free mass, crude fat, crude protein, protein to fat ratio, and tissue distribution. Regression equations were developed from BIA data obtained from the live animal to predict all carcass composition traits measured. Bioelectrical impedance analysis generated favorable results as a practical application to carcass composition evaluation in live tropical hair sheep.     

The major genetic determinants of HIV-1 control affect HLA class I peptide presentation

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.     

Comparison of faecal collection methods and diet acclimation times for the measurement of digestibility coefficients in barramundi (Lates calcarifer)

This study aimed to investigate the effects of two faecal collection methods (stripping and settlement) on the apparent digestibility coefficients (ADC) of dry matter, protein and energy of three different diets fed to barramundi. In a second experiment, the effect of acclimation time (i.e. number of days fed the diet) on the calculation of ADCs was also investigated. Each tank of fish was fed one of three diets for 12 days. Faeces were collected by both stripping and settlement, although only settlement was used prior to day seven of the acclimation period. Faeces were collected using the settlement method at regular intervals from day 1 to day 12. Comparisons between faecal collection methods were only made based on faecal material collected over a similar acclimation period. The collection of faeces by stripping produced more conservative ADCs, which were also more consistent than those obtained using the settlement technique. The calculated ADCs typically fluctuated for the first 3 days of collection before the variability diminished. Barramundi should be acclimated to diets for a minimum of 4 days before collection of faecal material, and collection by stripping is recommended to obtain the most reliable digestibility data.     

An analysis of the effects of different dietary macronutrient energy sources on the growth and energy partitioning by juvenile barramundi,Lates calcarifer,reveal a preference for protein‐derived energy

It is generally considered that fish respond to dietary energy densities on a consistent basis irrespective of what macronutrient source the dietary energy originates from. To test this assumption, two experiments were undertaken to establish the different roles of protein, lipid and starch as energy sources in underpinning nutritional bioenergetics in juvenile barramundi, Lates calcarifer. To do this, a range of ingredients were evaluated for their digestible protein (DP) and digestible energy (DE) value. Following this, a series of diets were formulated to an equivalent DE basis, and observed a minimum DP:DE ratio required for fish of 80 g. However, in each of the diets the proportion of DE available from protein, lipid or starch was varied to bias the contribution of each macronutrient on the origin that DE when fed to the fish. Growth of fish fed the protein diet was better than those fed the lipid diet, which was better than those fed the starch diet. Feed intake was lower in the protein diet than the lipid diet, and both were lower than the starch diet. Feed conversion was most efficient in the protein diet fed fish, which was better than the lipid diet fed fish, which was better than the starch diet fed fish. Whole fish composition varied among treatments, with differences observed in the dry matter composition, whole body lipid and gastrointestinal tract lipid content. Typically, lipid and dry matter composition were in synchrony and were usually higher in the starch fed fish and lower in the lipid fed fish. When flux of protein, lipid and energy was assessed in terms of deposition efficiencies, some significant differences were observed. Protein deposition efficiency was relatively conservative, but ranged from 33% in the starch diet fed fish to 41% in the lipid diet fed fish. Lipid deposition efficiency was more dramatic; ranging from 40% in the lipid diet to 182% in the starch diet. Energy deposition efficiency was relatively conservative among treatments, ranging from 50% to 56% efficient. Overall, the results from this study show that there is a clear hierarchy in preference for energy substrates by juvenile barramundi, such that protein > lipid > starch.     

A study of cells in the mammary secretions of sows

The morphology and some of the in vitro functional properties of the cells in the mammary secretions of sows have been examined. A mean cell yield of 1 × 10⁷ cells/ml was obtained from sow colostrum but during the first week post-partum the yield decreased approximately 10 fold. The polymorphonuclear leucocyte was the predominant cell type in colostrum and milk and was associated with varying proportions of lymphocytes, macrophages and epithelial cells. The phagocytes of sow milk ingested heat-killed yeast, although the phagocytic index for milk macrophages was low compared with autologous neutrophils and alveolar macrophages. Milk whey provided an effective opsonising medium for yeast ingestion. Intra-mammary immunisation of sows with ovalbumin induced antigen-reactive lymphocytes in both peripheral blood and milk.     

Cyclosporine decreases skin lesions and pruritus in dogs with atopic dermatitis: a blinded randomized prednisolone-controlled trial

During the last decade, oral cyclosporin (CsA) has proven to be effective, in randomized controlled trials, for the treatment of atopic dermatitis (AD) in human patients. The purpose of this blinded randomized controlled trial was to test the hypothesis that CsA was successful in reducing the gravity of clinical signs of AD in dogs. Thirty dogs with nonseasonal AD were randomly allocated to receive an oral solution of either NEORAL CsA (5 mg kg-1) or prednisolone (0.5 mg kg-1) once daily for 6 weeks. Before, and 3 and 6 weeks after therapy, skin lesions were graded by clinicians using the Canine AD Extent and Severity Index (CADESI). Pruritus was assessed by the owners using a visual analog scale (PVAS). In both groups, CADESI and PVAS values were significantly lower at 6 weeks post treatment than before the initiation of therapy (Friedman test, P < 0.0004). The percentage reductions in CADESI and PVAS values from baseline were not statistically different between groups (Mann-Whitney test, P > 0.3). In this experiment, the tolerability and safety of oral CsA and prednisolone appeared similar. One-fifth of dogs given oral CsA occasionally developed diarrhoea or soft stools. One dog that was given CsA developed a generalized papillomatous skin eruption during the second half of the trial. Our study provides randomized controlled trial evidence that CsA reduces the severity of clinical signs in dogs with nonseasonal AD. Moreover, the anti-allergic efficacy of CsA appears comparable with that of prednisolone. We propose that oral CsA should be considered as a valuable alternative to glucocorticoid therapy in dogs with AD.