1. A study was conducted to evaluate the individual and combined effects of aflatoxin B1 (AF), ochratoxin A (OA) and T-2 toxin (T-2) on performance, organ morphology serum biochemistry and haematology of broiler chickens and the efficacy of esterified-glucomannan (E-GM), a cell wall derivative of Saccharomyces cerevisiae1026 in their counteraction. 2. Two dietary inclusion rates of AF (0 and 0.3 mg/kg), OA (0 and 2 mg/kg), T-2 (0 and 3 mg/kg) and E-GM (0 and 1 g/kg) were tested in a 2 x 2 x 2 x 2 factorial manner on a total of 960 broiler chickens from 1 to 35 d of age in an open sided deep litter pen house. 3. Body weight and food intake were depressed by all the mycotoxins, OA being the most toxic during early life. 4. Weights of kidney and adrenals were increased by AF and OA. Liver weight was increased by AF (17.8%), while OA increased gizzard weight (14.6%) and reduced bone ash content (8.1%). T-2 toxin showed no effect on these variables. 5. Serum cholesterol content was decreased and activity of serum gamma glutamyl transferase (GGT) was increased by AF and OA while serum protein content was decreased by AF. These effects were more pronounced at 21 d than at 35 d of age. Inconsistent responses were seen in the other variables: blood urea nitrogen (BUN) content, activities of serum alanine amino transferase and aspertate amino transferase. Blood haemoglobin content was depressed by AF and T-2, whereas blood coagulation time was prolonged by OA. 6. Significant interactions were observed between any 2 toxins for their additive effects on body weight, food intake, bone ash content and serum GGT activity at 21 d. Conversely, antagonistic interactions were observed among any 2 of the toxins for their effects on variables such as serum protein and serum cholesterol content. Simultaneous feeding of all 3 mycotoxins did not show increased toxicity above that seen with any 2. 7. Esterified-glucomannan increased body weight (2.26%) and food intake (1.6%), decreased weights of liver (32.5%) and adrenals (18.9%) and activity of serum GGT (8.7%), and increased serum protein (14.7%), cholesterol (21.9%), BUN (20.8%) and blood haemoglobin (3.1%) content, indicating its possible beneficial effect on mycotoxicosis in broiler chickens.

An experiment was conducted to study the effect of graded levels of butyric acid (butyrate) on performance, gastrointestinal tract health and carcass characteristics in young broiler chickens. Control starter (0-3 wk) and finisher (4-5 wk) diets were formulated to contain 2,900 kcal ME/kg and 22% CP, and 3,000 kcal ME/kg and 20% CP, respectively. Subsequently, four other experimental diets were formulated to contain 0.05% antibiotic (furazolidone) or 0.2, 0.4 and 0.6% butyric acid. Each diet was fed at random to 8 replicates of 6 chicks each throughout the experimental period (0-5 wk). The results showed that 0.4% butyrate in the diet was similar to antibiotic in maintaining body weight gain and reducing E. coli numbers but superior for feed conversion ratio. No added advantage on these parameters was obtained by enhancing the concentration of butyrate from 0.4 to 0.6% in the diet. Feed intake and mortality were not influenced by the dietary treatments. A reduction in pH of the upper GI tract (crop, proventiculus and gizzard) was observed by inclusion of butyrate in the diets of broilers compared to either control or antibiotic-fed group. Butyrate at 0.4% was more effective in reducing the pH than 0.2% butyrate. Within the lower GI tract, 0.4 and 0.6% butyrate was effective in lowering pH in the duodenum, but no effect was found in either the jejunum or ileum. The villus length and crypt depth in the duodenum increased significantly in all the butyrate treated diets irrespective of the level tested. Carcass yield was higher and abdominal fat content was lower significantly in all the butyrate treatment groups compared to the control or antibiotic group. From these findings, it is concluded that 0.4% butyric acid supplementation maintained performance, intestinal tract health, and villi development and carcass quality in broiler chickens.

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An experiment was conducted to study the e#ect of dietary supplementation of probiotic Lactobacillus sporogenes (L. sporogenes) on performance and serum biochemico-lipid profile of broiler chickens. One hundred and twenty, day-old commercial broiler chicks were distributed equally into -groups of .* chicks each, which was further replicated to 2 groups of / each. The chicks were placed on one of three dietary treatments : basal, basal with probiotic (0ῌ+* 2 spore of Lactobacillus sporogenes per g) at +** or ,** mg per kg feed. Body weight gain increased and feed conversion ratio improved significantly due to dietary supplementation of +** mg probiotic per kg diet. However, no further benefits on the above parameters could be observed by increasing the level of supplementation from +** to ,** mg per kg. Leg abnormality score is not influenced by probiotic supplementation in the diet. However, the bone breaking strength and bone ash content increased significantly by probiotic supplementation at +** mg per kg diet. The concentration of protein and calcium increased significantly due to dietary supplementation of L. sporogenes. Neither concentration of inorganic phosphorus nor activities of enzymes such as serum glutamate-oxaloacetate transminae (SGOT), serum glutamate-pyruvate transaminase (SGPT) and alkaline phosphatase (ALP) in serum were influenced due to L. sporogenes supplementation. Serum total cholesterol, low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (VLDL) cholesterol and triglycerides were reduced significantly by dietary supplementation of L. sporogenes at +** mg per kg diet. However, high-density lipoprotein (HDL) cholesterol of birds was not influenced by L. sporogenes supplementation. It is concluded that dietary supplementation of Lactobacillus sporogenes (0ῌ+* 2 spore per g) at +** mg per kg diet significantly enhanced body weight gain, improved feed conversion ratio, bone ash and bone breaking strength and lowered total cholesterol, VLDL cholesterol and triglycerides concentrations in the serum of broiler chickens.

The effect of probiotic (Lactobacillus sporogenes) feeding on egg production and quality, yolk cholesterol and humoral immune response of White Leghorn (WL) layer breeders was studied. WL layer breeders (24 weeks) were randomly distributed into three groups of 28 each and were housed in individual California type cages. Considering one bird (individual feeding) as a replicate, 28 such replicates were randomly allotted to one of the three dietary treatments: basal (control) or basal with probiotic supplementation at a rate of 100 or 150 mg kg −1 feed. The probiotic used in the study was a commercial preparation containing L. sporogenes with 6000 million spores g −1 of the product. Dietary supplementation of L. sporogenes at 100 mg (6 × 10 8 spore) kg −1 diet significantly increased egg production and feed efficiency. However, body weight gain, feed intake, egg weight, specific gravity and Haugh unit was not influenced by probiotic feeding. The eggshell breaking strength, shell weight and shell thickness increased significantly by feeding 100 mg probiotic kg −1 diet. The serum concentration of calcium and protein increased, and that of cholesterol decreased by L. sporogenes supplementation. The yolk cholesterol followed the same trend of serum cholesterol. Feeding of L. sporogenes significantly enhanced antibody production. No difference in antibody production could, however, noticed between the levels (100 or 150 mg) of probiotic. It is concluded that feeding of L. sporogenes at 100 mg (6 × 10 8 spore) kg −1 diet significantly enhanced the egg production, shell quality and humoral immune response of WL layer breeders during 25-40 weeks of age.