Showing papers by "Tim A. McAllister published in 1995"

Effects of giardiasis on production in a domestic ruminant (lamb) model

Abstract: OBJECTIVE To examine the effects of giardiasis on production and carcass quality, using growing lambs as a domestic ruminant model. DESIGN Randomized block. ANIMALS Giardia-free lambs: 23 in infected group, 24 in control group. PROCEDURE Six-week-old, specific-pathogen-free lambs were infected with Giardia trophozoites; control lambs received saline solution. Clinical signs of infection, body weight, and feed intake were determined for 10 weeks. Carcass weight and quality were determined at slaughter weight of 45 kg. RESULTS Giardia infection persisted from weeks 7 to 16. For 5 weeks after challenge exposure, abnormal feces were more frequently observed in infected lambs. Giardia infection was associated with a decrease in rate of weight gain and impairment in feed efficiency. Time to reach slaughter weight was extended in infected lambs, and the carcass weight of Giardia-infected lambs was lower than that of control lambs. CONCLUSION Giardiasis has a negative effect on domestic ruminant production. CLINICAL RELEVANCE Giardiasis in domestic ruminants is an economically important disease, thus necessitating control or elimination of the infection.

Intake, digestibility and aerobic stability of barley silage inoculated with mixtures of Lactobacillus plantarum and Enterococcus faecium

Abstract: The effect of ensiling barley treated with two bacterial inoculants containing mixtures of Lactobacillus plantarum and Enterococcus faecium (1.0 × 105 cfu g−1 as fed silage) on the nutritional value and aerobic stability of barley silage was examined. Inoculants differed in the strains they contained and were originally selected by Pioneer Hi-Bred International for use with corn or alfalfa silage, SILA-BAC® (1174), or with grass silage (X2637). Concentrations of water-soluble carbohydrates were higher (P < 0.05) in inoculated than in control silages. Although inoculants appeared to increase the numbers of lactic acid producing bacteria (LAB) at ensiling, post-ensiling numbers (cfu g−1) of yeasts and molds were lower (P < 0.05) in inoculated than in control silages. Lactic acid concentrations and pH were similar among the silages and variations m the growth of yeast and mold populations could not be explained by differences in the production of volatile fatty acids (VFA) among silages. Inoculation of barle...

Comparison of lignosulfonate-treated canola meal and soybean meal as rumen undegradable protein supplements for lambs

Abstract: An experiment was undertaken to determine the effect of lignosulfonate (LSO3) treatment on the rumen-undegradable protein (RUDP) value of canola meal (CM) and soybean meal (SM). Canola meal and SM were treated with 7% LSO3 and heated (95 °C) for 1 h. Treated and untreated meals were compared in vitro, in situ and in digestibility and growth experiments using Romanov × Suffolk and Romanov × Dorset lambs. Lambs were fed four barley-based diets [13.5% crude protein (CP)] with one of CM, SM, LSO3-treated CM (LSO3-CM) or LSO3-treated SM (LSO3-SM) as protein supplements. Lignosulfonate treatment increased acid detergent insoluble nitrogen (ADIN) five-fold in SM and threefold in CM. After 6 h incubation with ruminal fluid, ammonia production from LSO3-treated meals was one-half that from untreated meals. Lignosulfonate treatment reduced (P < 0.01) in situ rates of dry matter (DM) and protein disappearance and the soluble DM and protein fractions for both SM and CM, but not the potentially digestible fractions. N...

Lignosulfonate-treated canola meal for nursing beef calves

Abstract: A study was conducted to determine the effects of lignosulfonate and heat treatment of canola meal on protein degradability, and to evaluate whether feeding treated canola meal to nursing beef calves enhances preweaning growth. Four supplements were formulated to contain 31% crude protein (CP) using either: (1) untreated canola meal (UTC), (2) heat-treated canola meal (HTC; 100 °C for 1 h), (3) lignosulfonate-treated canola meal (LTC; 5% calcium lignosulfonate and 100 °C for 1 h), or (4) corn distillers' dried grains (DDG). Degradability of canola meal CP was reduced significantly from 55.1% (measured in sacco) to 43.2% by heat, and to 26.7% by lignosulfonate treatment. One hundred and three nursing crossbred calves were given access to either no supplement (control) or one of the four supplements. Weight gain (kg d−1) increased (P < 0.05) from 0.90 for the control to 1.05 for calves fed DDG, and further increased (P < 0.05) to 1.16, 1.16 and 1.18 for calves fed UTC, HTC, and LTC, respectively. Consequent...