The effect of varying levels of purified condensed tannins on performance, blood profile, meat quality and methane emission in male Bapedi sheep fed grass hay and pellet-based diet.

This study determined the effect of purified condensed tannin inclusion levels in a diet on production, haematological indices, blood biochemical components, meat quality and methane emission by yearling indigenous male Bapedi sheep on a grass hay and sheep pellet-based diet in a 28-day trial. The diets contained similar (P > 0.05) nutrients but with different (P < 0.05) purified condensed tannin supplementation levels. A complete randomized design was used. Twenty-four yearling male Bapedi sheep were assigned to four dietary treatments having different purified condensed tannin levels of 0 (GH80P20PCT0), 30 (GH80P20PCT30), 40 (GH80P20PCT40) and 50 (GH80P20PCT50) g/kg DM. A quadratic type of equation was also used to determine condensed tannin supplementation levels for optimal performance and methane emission reduction by sheep. Supplementing diets with purified condensed tannins did not affect (P > 0.05) diet intake, digestibility and live weight gain of male Bapedi sheep. Supplementing diets with purified condensed tannins did not affect (P > 0.05) blood components of male Bapedi sheep. Inclusion of condensed tannins in the diets did not affect (P > 0.05) Bapedi sheep meat pH and sensory attributes. However, supplementing diets with purified condensed tannins decreased (P < 0.05) methane emission by 51 to 60%. A 49.08 g supplementation level with purified condensed tannins per kg DM diet was calculated, with the use of quadratic equations, to result in the lowest methane emission by male Bapedi sheep. The meat of male Bapedi rams on diets containing 30, 40 or 50 g of purified condensed tannins per kg DM contained higher (P < 0.05) antioxidant activities than those from rams fed a diet without purified condensed tannins. These results indicate that purified condensed tannin supplementation levels of 0, 30, 40 or 50 g/kg DM diet had no adverse effects on growth performance, blood profiles and meat sensory attributes of male Bapedi sheep. However, supplementation levels of 30, 40 or 50 g of purified condensed tannins per kg DM diet reduced methane emission by 51 to 60%, and increased sheep meat antioxidant activity values. Supplementing diets with purified condensed tannins has the potential to reduce methane production and emission by sheep. However, long-term studies are recommended to ascertain the present findings.

Effect of pre-weaning selection on estimates of genetic parameters and breeding values for post-weaning growth rate of beef bulls on test.

Data on South African Angus cattle consisting of 45 259 records on weaning weight (WWT), 4 360 records on average daily gain from on-farm test (ADG-D) and 1 118 from centralized test (ADG-C) were analyzed to evaluate the effect of pre-weaning selection on estimates of genetic parameters and subsequent estimated breeding values (EBV) for post-weaning average daily gain. (Co)variance components and genetic parameters for weaning weight (WWT), ADG-C and ADG-D were estimated by REML procedures fitting three different animal models. Model 1 was a univariate model of WWT, ADG-C or ADG-D and did not account for the effect of pre-weaning selection on post-weaning ADG. Model 2 was a two-trait model of WWT and either ADG-C or ADG-D. Model 3 was a multi-trait animal model including WWT, ADG-C and ADG-D. Estimates of heritability for ADG-C were 0.39 +/- 0.080, 0.42 +/- 0.060 and 0.44 +/- 0.010 from Model 1, 2 and 3 respectively. Corresponding estimates for ADG-D were 0.18 +/- 0.020, 0.19 +/- 0.020 and 0.21 +/- 0.020 respectively. Rank correlations based on EBVs for ADG-C for all bulls were 0.92, 0.83 and 0.94 for Model 1 vs. Model 2, Model 1 vs. Model 3, and Model 2 vs. Model 3, respectively and they indicated a possible re-ranking of bulls when including or excluding a correlated pre-weaning trait. Rank correlations for ADG-D also followed a similar trend. Inclusion of pre-weaning information in genetic analysis for post-weaning average daily gain is necessary to account for selection at weaning.

Effect of Aqueous Moringa Oleifera (Lam) Leaf Extracts on Growth Performance and Carcass Characteristics of Hubbard Broiler Chicken

Two hundred and forty day old broiler chicks were used to investigate the effect of aqueous Moringa oleifera leaf extracts (AMOLE) on growth performance and carcass characteristics of broiler chicken. The birds were randomly allocated into six treatments with four replicates, and each replicate containing 10 broiler chicks; the CRD was used. The treatments contained AMOLE0+ (positive control with antibiotic treatment), AMOLE0- (negative control with ordinary water), AMOLE60 (60 ml/l), AMOLE90 (90 ml/l), AMOLE120 (120 ml/l) and AMOLE150 (150 ml/l) inclusion levels of AMOLE, respectively. Birds on positive control had the highest final body weight and growth rate (2392.00 g and 53.61 g respectively) and the ones on 150 ml/l of AMOLE had the least (2042.00 g and 45.37 g respectively). Results of feed intake showed that birds on positive control had the highest (84.70 g) and the ones on 90 ml/litre of AMOLE had the lowest (73.19 g); while the results of feed conversion ratio indicated that birds on AMOLE90 and AMOLE120 performed better than the positive control treatment. Birds on the AMOLE had similar dressing percentages though that of positive control was highest (94.93 %); while those on AMOLE60 and AMOLE150 had the highest large intestine and lung weights respectively. Aqueous Moringa oleifera leaf extract can be included up to 90 ml/litre in the drinking water of broiler chicken for reduced feed intake (12.83 %) and improved feed conversion efficiency (9.11) thus, AMOLE can be used to replace synthetic antibiotics as growth promoter.(AU)

Breed and Sex Differences in the Gross Anatomy, Digesta pH and Histomorphology of the Gastrointestinal Tract of Gallus Gallus Domesticus

A study was conducted to investigate the influence of breed and sex in the gross anatomy, digesta and histology of Ross 308 broiler and Venda chickens. Chickens were slaughtered at 90 days of age and the pH of the digestive organs was measured immediately after slaughter. The digestive organ weights and lengths of Ross 308 broiler and Venda chickens were measured. Tissue samples of the duodenum, ileum and jejunal from each treatment group were collected and histologically examined. Higher (p 0.05) gizzard pH values were observed in male and female of Ross 308 broiler and Venda chickens. The jejunal and ileal pH values were lower (p 0.05) for Venda chickens than in Ross 308 broiler chickens. The absolute weights of the gastrointestinal tract, crop, proventriculus and gizzard were lighter (p 0.05) in Venda chickens than in Ross 308 broiler chickens. The relative organ weights of the GIT, proventriculus, gizzard and caeca were higher (p 0.05) in Venda chickens than in Ross 308 broiler chickens aged 90 days. Male chickens had higher (p 0.05) relative organ weights than female chickens. Interactions between breed and sex influenced (p 0.05) the absolute weights of the crop, proventriculus, caeca and large intestine. Ileum villus heights of female Venda chickens were higher (p 0.05) than those of female and male Ross 308 broiler and Venda chickens. The male and female Ross 308 broiler chickens had higher (p 0.05) ileum and duodenum crypt depths than male and female Venda chickens. The duodenum and ileum villus height/crypt depth ratios were higher (p 0.05) in male and female Venda chickens than Ross 308 broiler chickens. In overall, male broiler chicken performed better.(AU)

Breed and Sex Differences in the Gross Anatomy, Digesta pH and Histomorphology of the Gastrointestinal Tract of Gallus Gallus Domesticus

A study was conducted to investigate the influence of breed and sex in the gross anatomy, digesta and histology of Ross 308 broiler and Venda chickens. Chickens were slaughtered at 90 days of age and the pH of the digestive organs was measured immediately after slaughter. The digestive organ weights and lengths of Ross 308 broiler and Venda chickens were measured. Tissue samples of the duodenum, ileum and jejunal from each treatment group were collected and histologically examined. Higher (p 0.05) gizzard pH values were observed in male and female of Ross 308 broiler and Venda chickens. The jejunal and ileal pH values were lower (p 0.05) for Venda chickens than in Ross 308 broiler chickens. The absolute weights of the gastrointestinal tract, crop, proventriculus and gizzard were lighter (p 0.05) in Venda chickens than in Ross 308 broiler chickens. The relative organ weights of the GIT, proventriculus, gizzard and caeca were higher (p 0.05) in Venda chickens than in Ross 308 broiler chickens aged 90 days. Male chickens had higher (p 0.05) relative organ weights than female chickens. Interactions between breed and sex influenced (p 0.05) the absolute weights of the crop, proventriculus, caeca and large intestine. Ileum villus heights of female Venda chickens were higher (p 0.05) than those of female and male Ross 308 broiler and Venda chickens. The male and female Ross 308 broiler chickens had higher (p 0.05) ileum and duodenum crypt depths than male and female Venda chickens. The duodenum and ileum villus height/crypt depth ratios were higher (p 0.05) in male and female Venda chickens than Ross 308 broiler chickens. In overall, male broiler chicken performed better.

Genetic parameter estimates for body weight in local Venda chickens.

Genetic parameters were estimated for Venda chicken body weights at hatching, and at 4 weeks, 10 weeks and 21 weeks of age. A single-trait animal model with restricted maximum-likelihood procedures was used. Random effects were additive direct and maternal genetic, common environmental and error. The heritability estimates for direct effects were 0.36, 0.25, 0.41 and 0.22 for hatch, 4 weeks, 10 weeks and 21 weeks, respectively. The maternal effects were estimated at hatch and 4 weeks of age and were not present at later ages. Common environmental effects disappeared with increasing age. There was an antagonistic relationship between direct and maternal effects. The results show potential for genetic improvement of indigenous Venda chickens through selection. Maternal effects should be considered if selection is carried out at early ages.