Immunohistological studies of the local immune system in the reproductive tract of the mare

The immunoperoxidase technique was adapted for the identification of free immunoglobulin and immunoglobulin producing cells in equine tissues. Staining specific for free IgG, IgA and IgM was detected at all levels of the reproductive tract, and secretory component staining was present in the uterine epithelium but not in the oviduct, cervix or vagina. Immunoglobulin producing cells were present at all levels of the tract, with IgG and IgA cells at equivalent concentrations, but with fewer IgM cells. There was no cyclical trend in free immunoglobulin staining, or plasma cell numbers. IgG and IgM plasma cell numbers declined from uterus to vagina, as did epithelial staining, and the ratio of IgG:IgA cells declined from oviduct to vagina.     

Nematophagous Verticillium spp. in soils infested with Meloidogyne spp. in Cuba: Isolation and screening

Root-knot nematodes cause substantial economic loss of yield in coffee plantations and vegetable crops in Cuba. At present, methods to control the nematodes are ineffective or inappropriate and alternatives are being sought. The nematophagous fungus Verticillium chlamydosporium (Goddard) was isolated from soils collected from coffee plantations and infected root-knot nematode eggs from roots of tomato plants grown in these soils. A total of 83 isolates were collected and identified morphologically as V. chlamydosporium var. chlamydosporium, V. chlamydosporium var. catenulatum, V. psalliotae, V. suchlasporium and an isolate of V. chlamydosporium var. chlamydosporium with unusually large dictyochlamydospores. From these, 24 that represented a range of origins were selected and screened for their ability to parasitize eggs of root-knot nematodes, colonize the rhizosphere of barley roots and produce chlamydospores. None of the isolates grew at temperatures below 15°C and V. suchlasporium grew at a faster rate at lower temperatures than the other isolates. These were also screened in the glasshouse and V. chlamydosporium var. catenulatum caused the greatest reduction in nematode populations. One isolate of each subspecies of V. chlamydosporium was tested with the standard, Rothamsted isolate 10, on a range of host plants. The greatest reduction in numbers of nematodes occurred on tomato plants (cv. Pixie). The Rothamsted isolate 10 reduced numbers of nematodes toa greater extent than the other isolates, and therefore has the greatest potential as a biological control agent of root-knot nematodes.     

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.     

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.