34 research outputs found
The effect of rumen inert fat supplementation and protein degradability in starter and finishing diets on veal calf performance
Thirty six Holstein bull calves were divided into six groups to determine the effect of protein degradability and rumen inert fat supplementation in starter and finishing diets on nutrient digestibility and veal production. Calves received low (LD) or high (HD) degradable protein diets, with or without rumen inert fat supplementation. Two commercial fat sources were used, Morlac (mlc) and Golden Flake (gf), included in the experimental diets at 2.5% of dry matter (DM). A commercial milk replacer was fed to all calves at 4 L/day for 42 days, followed by 2 L/day until weaning at 49 days of age. Starter diets were offered ad lib. from day 14 to 10 weeks of age and finishing diets ad lib. from 11 to 20 weeks of age. All calves were slaughtered at 20 weeks to determine carcass weight and dressing percentage. There were no significant differences in body weight gain or dry matter intake over the entire 20 week period. Feed conversion ratio (FCR) was improved when fat was supplemented to LD, but not to HD diets. The FCR (DM intake/kg gain) of LD, HD, LDmlc, HDmlc, LDgf and HDgf diets was 3.45, 3.44, 3.07, 3.81, 3.02 and 3.43, respectively. All 36 calves were used in a digestibility trial during week 18 of the study, using chromium oxide as a marker. Apparent digestibility values (%) for LD, HD, LDmlc, HDmlc, LDgf and HDgf, respectively, were 61.7, 65.9, 75.4, 69.0, 75.5 and 67.2 for DM, 61.4, 61.6, 71.3, 68.2, 75.4 and 66.1 for crude protein and 58.6, 66.5, 76.0, 70.9, 78.4 and 70.8 for fat. Dry matter and fat digestibilities were significantly higher when fat was added to LD diets, but not to HD diets. The CP digestibility was significantly higher when fat was added to either the LD or the HD diets. It was concluded that rumen inert fat supplementation to calf diets appears to improve feed conversion ratio and DM and fat digestibilities, but only when added to low degradable protein diets and only after 10 weeks of age. Crude protein digestibility appears to improve with fat supplementation to either high or low degradable protein diets.
Keywords: Calves, Nutrition, Fat supplementation, Protein degradability, Nutrient digestibility, Veal production
South African Journal of Animal Science Vol.33(4) 2003: 257-26
Variation in the chemical composition, physical characteristics and energy values of cereal grains produced in the Western Cape area of South Africa
Grain samples were produced at 10 different locations in the Western Cape region of South Africa, on 2.1 m x 6 m experimental plots, over a period of three years. Twenty different cereal grain cultivars were used in the study. A randomised square experimental design with four replicates per sample was used. An area of 1.35 m x 5 m from each plot was harvested during 1994, 1995 and 1996 and the yield was determined. Thousand seed mass (TSM) and hectolitre mass (HLM) were also determined. Samples were analysed for dry matter (DM), ash, crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF) and in vitro organic matter digestibility (IVOMD). Digestible energy values (DE) for pigs were determined with a mobile nylon bag technique, while non-structural carbohydrate values (NSC) were calculated. In the first analysis, cultivars were compared by a one-way analysis of variance, followed by pooling of grain type data. Naked oats had the highest DE value, and the respective values (DM basis) for naked oats, wheat, triticale, 2-row brewer's barley, 6-row feed barley and oats were 18.0, 16.0, 15.8, 14.9, 14.4, and 12.6 MJ/kg DM. The high EE value of naked oats (97 g/kg) might be partly responsible for the high DE value. The 6-row and 2-row naked barley cultivars had the highest IVOMD (946 g/kg and 944 g/kg), followed by wheat (910 g/kg), triticale (905 g/kg), naked oats (899 g/kg), 2-row brewer's barley (882 g/kg), 6-row feed barley (844 g/kg) and oats (671 g/kg). Considerable variation was found between samples within a cultivar for DE and IVOMD. Two-row naked barley had the highest mean CP value (159 g/kg) followed by naked oats (159 g/kg), 6-row naked barley (154 g/kg), wheat (148 g/kg), triticale (146 g/kg), oats (143 g/kg), 2-row brewer's barley (136 g/kg) and 6-row feed barley (135 g/kg) on DM basis. Triticale had the highest yield, with naked oats and barley cultivars having the lowest yield.
Keywords: Cereal grains, Chemical composition, Energy value
South African Journal of Animal Science Vol.33(2) 2003: 117-12
Melamine Impairs Renal and Vascular Function in Rats.
Melamine incident, linked to nephrotoxicity and kidney stone in infants previously exposed to melamine-contaminated milk products, was unprecedentedly grave in China in 2008 as little was known about the mechanistic process leading to renal dysfunction in affected children. This study investigates whether neonatal ingestion of melamine leads to renal and vascular dysfunction in adulthood; and whether ingestion of melamine in pregnant rats leads to renal dysfunction in their offspring. A combination of approaches employed includes functional studies in rat renal arteries, renal blood flow measurement by functional magnetic resonance imaging, assay for pro-inflammatory and fibrotic biomarkers, immunohistochemistry, and detection of plasma and renal melamine. We provide mechanistic evidence showing for the first time that melamine reduces renal blood flow and impairs renal and vascular function associated with overexpression of inflammatory markers, transforming growth factor-β1, bone morphogenic protein 4 and cyclooxygenase-2 in kidney and renal vasculature. Melamine also induces renal inflammation and fibrosis. More importantly, melamine causes nephropathies in offsprings from pregnant rat exposed to melamine during pregnancy, as well as in neonatal rat exposed to melamine afterbirth, thus supporting the clinical observations of kidney stone and acute renal failure in infants consuming melamine-contaminated milk products.This study was supported by the Food and Health Bureau Grant, Hong Kong SAR (MI-BS-12), CUHK Vice Chancellor’s Discretionary Fund and CUHK Investment Scheme B
Optimizing soybean flour-, whey powder- and colostrum ratios for rearing dairy calves
No Abstract
Optimizing soybean flour-, why powder- and colostrum ratios for rearing dairy calves
No Abstract
The effect of supplemental biotin in dairy cow diets on fibre fermentation patterns as measured by <I>in vitro</I> gas production.
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The effect of dietary rumen degradable protein content on veal calf performance.
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Effect of an exogenous fribolytic enzyme on growth rate, feed intake and feed conversion ratio in growing lambs.
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The effect of age on <I>in sacco</I> estimates of rumen dry matter and crude protein degradability in veal calves.
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Veal calf performance in response to concentrate diets of different of rumen degradable protein.
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