Effects of exogenous tannase enzyme on growth performance, antioxidant status, immune response, gut morphology and intestinal microflora of chicks fed grape pomace

An experiment was conducted to study the effects of dietary addition of tannase to feed of chicks including grape pomace (GP) on growth performance, antioxidant status, immune response, blood parameters, gut morphology, intestinal microflora, liver function, and histopathological responses. The experimental diets were i) control (corn and soybean diet) (C); ii) C+10%GP; iii) C+10%GP+T1 (500 mg/kg tannase enzyme); and iv) C+10% GP+T2 (1000 mg/kg tannase enzyme). At 10 days old, the bodyweight (BW) and average daily gain (ADG) of the birds fed the diet supplemented with GP was lower compared with the control group. In contrast with the control, supplementation of diets with 10%GP+1000 mg/kg tannase elevated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and depressed the malondialdehyde (MDA) level in serum. The addition of GP to the chicken diets had a significant impact on the total anti- sheep red blood cells (SRBC) titers and IgG, and IgM antibodies at 21 and 42 days old. The muscularis thickness of the chicken duodenum decreased in the Trial 3 compared with control groups. The inclusion of GP in the chicken diets reduced the concentration of Escherichia coli and increased that of Lactobacillus compared with the control. The results of the present study suggest that the inclusion of up to 10 percent GP in diets did not adversely affect broiler growth performance, and supplementation of tannase improved the antioxidant status and immune responses,and increased the caecal populations of beneficial bacteria in the cecum of broiler chickens.Keywords: Broiler chickens, histopathological responses, glutathione peroxidase, polyphenol, sheep red blood cell

Effects of grape pomace and vitamin E on performance, antioxidant status, immune response, gut morphology and histopathological responses in broiler chickens

We investigated the effects of grape pomace (GP) and vitamin E on the performance, antioxidant status, immune response, gut morphology and histopathological responses in broiler chickens. Two hundred and fifty male broiler chickens (Ross 308) were allocated to five dietary treatments (50 birds/treatment) in a completely randomized design. The experimental diets were as follows: i) Control corn-soybean meal diet (C); ii) C + Vitamin E (200 mg/kg of α-tocopherol acetate); iii) The diet containing 5%GP; iv) The diet containing 7.5% GP; v) The diet containing 10% GP. No differences were found in performance of the experimental birds. Birds fed 7.5% GP showed a significant increase in superoxide dismutase (SOD), glutathione peroxidise (GSH-Px) activity and reduced malondialdehyde (MDA) concentration. Antibody titer against Newcastle disease virus (NDV) at 42 days (d) of age in the control and 7.5% GP fed groups were lower than others. The primary IgM concentration of birds fed 10% GP was higher than the birds fed the control diet, the vitamin E supplemented diet or the diet containing 5% GP. The secondary titer against sheep red blood cells (SRBC) was increased significantly in the birds fed 10% GP and the secondary IgG concentration of birds fed 10% GP was higher than the birds fed the control diet and the diets containing 5% or 7.5% GP. In duodenum part of small intestine, villus height/crypt depth ratio and muscularis thickness were decreased. The results of the present study suggest that the inclusion of up to 10% GP in diets did not adversely affect broiler chickens’ performance and improved the antioxidant and immune responses of broiler chickens.Keywords: Glutathione peroxidise, polyphenol, poultry, red blood cells α-tocopherol acetate, sheep, superoxide dismutas

Effect of zinc sources on milk yield, milk composition and plasma concentration of metabolites in dairy cows

This study was conducted to evaluate the effects of different sources of zinc (Zn) on feed intake, milk yield, milk composition, and blood metabolites. Twenty-four dairy cows were randomly allocated to one of four treatments in a randomized complete block design. The treatments consisted of i) control diet (no zinc supplementation), ii) zinc oxide (ZnO), iii) zinc glycine (ZnGly), and iv) zinc nano (ZnN). The Zn sources were added to provide 60 mg of supplemental Zn per kg diet. There were no differences in dry matter intake, milk yield, bodyweight, and body condition score of the cows between treatments. Zinc supplementation in the form of ZnN and ZnGly decreased somatic cell count compared with the other treatments. The superoxide dismutase and plasma Zn concentrations in the cows provided ZnGly and ZnN were greater than those in the ZnO and control groups. No difference was detected between groups in biochemical and haematological parameters, except that blood urea nitrogen concentrations of cows supplemented with ZnGly and ZnN were less than for the ZnO supplemented and control cows. The results showed that nano and organic Zn sources in the diet of dairy cows were more suitable than inorganic Zn as supplements for dairy cows.Keywords: milk composition, milk production, metabolism, somatic cell coun

Environmental efficiency of Saccharomyces cerevisiae on methane production in dairy and beef cattle via a meta-analysis

8 páginas, 2 tablas, 4 figuras.The objective of the present study is to examine the effect of yeast (Saccharomyces cerevisiae) on reduction of methane (CH) production in dairy and beef cattle using meta-analytic methods. After compilation of relevant scientific publications available from the literature between 1990 and 2016, and applying exclusion and inclusion criteria, meta-analyses of data from dairy and beef cattle were applied for the pooled dataset or for each animal category (dairy or beef). The results of meta-analysis of all three datasets (all cattle, dairy cattle, or beef cattle) suggested that effect size of yeast either on daily CH production or on CH production per dry matter intake (CH/DMI) was not significant. The results of Q test and I statistic suggest that there is no heterogeneity between different studies on CH production and CH/DMI. The results of meta-analysis suggest that use of yeast (Saccharomyces cerevisiae) as feed additive does not offer significant results in terms of reduction of CH production in dairy and beef cattle. Further research on the effects of different doses of yeast, use of yeast products, different strains, and experimental designs is warranted to elucidate the effects of yeasts on methane production in the rumen