Scielo RSS <![CDATA[South African Journal of Animal Science]]> vol. 49 num. 2 lang. <![CDATA[SciELO Logo]]> <![CDATA[<b>Co-products in maize-soybean growing-pig diets altered <i>in vitro </i>enzymatic insoluble fibre hydrolysis and fermentation in relation to botanical origin</b>]]> The study examined the effects of botanical factors and fermentation-based, high-level dilution of co-product feeds in maize-soybean growing-pig diets on enzymatic insoluble fibre hydrolysis and fermentation. Feed insoluble fibre residues that were recovered after pepsin-pancreatin digestion were subjected to Roxazyme® G2 (Roxazyme) versus Viscozyme L® V2010 (control) hydrolysis, and to 64-hour fermentation using pig faecal inoculum. The control diet was a 13 MJ metabolizable energy, 141 g total dietary fibre/kg dry matter maize-meal/hominy chop-soybean diet, which was diluted with maize cob, soybean hulls, barley brewer's grains, lucerne hay or wheat bran in 12 MJ metabolizable energy, 246 g total dietary fibre/kg dry matter iso-nutrient, single co-product test diets. Fermentable insoluble fibre was employed in a computerized iterative selection of ingredients in two iso-nutrient 11 MJ metabolizable energy 319 total dietary fibre/kg dry matter mixed fibre test diets for maximal contrast (high (HF) versus low (LF)) in fermentability. Insoluble fibre extractive pepsin-pancreatin digestibility differed between feed ingredients, and the single co-product test diets, and between the HF and LF mixed co-product diets. Fibre digestibility depended on both the origin and enzyme, with interaction, whereby carbohydrases expressed similar low (0.04 - 0.05) insoluble fibre digestibility for maize cob, moderate (0.12) digestibility for wheat bran and brewer's grain, with inferior Roxazyme G2 digestibility for maize hominy chop (0.02 vs 0.10) and meal (0.04 vs 0.16), dehulled soybean meal (0.02 vs 0.17), lucerne hay (0.08 vs 0.18), and soybean hulls (0.05 vs 0.33). Co-product-enzyme affinities were expressed in single fibre diets. Low Roxazyme-basal fibre affinity limited its comparative single co-product (0.03 - 0.07 vs 0.16 - 0.22) HF (0.07 vs 0.17) and LF (0.4 vs 0.20) dietary fibre digestibility. Screening for HF/LF did not affect enzymatic digestion, though enzyme combination increased HF, but not LF digestibility. Gas and short chain fatty acid production predicted fermentability proportionately in the declining order of dehulled soybean > maize > soy hulls > maize hominy chop > wheat bran >lucerne hay > brewer's grain = maize cob. Induced HF and LF contrast was significant. Co-product fibre enrichment decreased fermentability for all except the soy hull and HF diets. Cereal fibre yielded proportionately less acetate, with more propionate and butyrate, and a greater butyrate shift for maize fibre. The HF fibre induced more ACE and less butyrate. Biomarkers of deleterious proteolytic fermentation were high for lucerne (iso-butyrate) and soy hulls (iso-valerate). In conclusion, high-level and fermentation based co-product feed dilution into maize-soybean growing pig diets altered enzymatic insoluble fibre hydrolysis and fermentation in relation to botanical origin. Roxazyme expressed weak hydrolytic potency on maize and soybean insoluble fibre. <![CDATA[<b>Effect of probiotics, <i>Saccharomyces </i>spp.Kb-5 and Kb-8, in diets on growth performance and cholesterol levels in ducks</b>]]> The study was conducted to determine the effect of the probiotics, Saccharomyces spp.Kb-5 and Saccharomyces spp.Kb-8, on growth performance, carcass characteristics, serum and meat cholesterol levels in ducks. Two hundred and forty 1-day-old healthy male ducks were randomly allocated to four treatment groups: A) basal diet (control), B) basal diet + 0.20% Saccharomyces spp.Kb-5, C) basal diet + 0.20% Saccharomyces spp.Kb-8, and D) basal diet + 0.10% Saccharomyces spp.Kb-5 + 0.10% Saccharomyces spp.Kb-8. Growth performance, carcass characteristics, and serum and meat cholesterol levels were determined when the ducks were 56 days old. Saccharomyces spp.Kb-5 and Saccharomyces spp.Kb-8, and the incombination, increased bodyweight gains, feed efficiencies and carcass weight significantly, but not affect the amount of feed consumed. The administration of Saccharomyces spp. results in significant lower serum and meat cholesterol concentrations compared to the control. It was concluded that the addition of Saccharomyces spp.Kb-5 and Saccharomyces spp.Kb-8, and the incombination, in the diet increased growth performances, feed efficiency and carcass weight, and decreased serum and meat cholesterol concentrations in male ducklings. <![CDATA[<b>Hydrogen peroxide concentration and DNA fragmentation of buffalo oocytes matured in sericin-supplemented maturation medium</b>]]> This study was conducted to investigate the effects of sericin on meiotic maturation, hydrogen peroxide (H2O2) concentration and deoxyribonucleic acid (DNA) fragmentation in buffalo oocytes. Oocytes were matured in vitro in tissue culture medium (TCM-199) with in vitro maturation (IVM) groups under several conditions, namely without bovine serum albumin (-BSA), (+BSA), and 0.025%, 0.05%, 0.1% and 0.25% (w/v) sericin. The results showed that supplementation of the maturation medium with 0.05% sericin significantly increased the rate of oocytes that reach metaphase II compared with other groups, except for the 0.025% sericin-treated group. Intracellular H2O2 concentrations in oocytes of all groups were measured using 2',7'-dichlorodihydrofluorescein diacetate (DCHFDA). The concentration of H2O2 in matured oocytes treated with 0.05% sericin was lower than in other groups. DNA fragmentation and the nuclear status of oocytes were examined using the terminal deoxyribonucleotidyl transferase-mediated dUTP digoxigenin nick end-labelling (TUNEL) method. The total proportion of TUNEL-positive oocytes at the MII stage was lower in the 0.05% sericin group. The results indicate that addition of 0.05% sericin to the maturation medium may improve nuclear maturation and may inhibit DNA fragmentation in oocytes by decreasing H2O2 concentrations. <![CDATA[<b>Prebiotic effects of oligosaccharides extracted from palm kernel expeller on different levels of <i>Salmonella typhimurium </i>infection in chicks</b>]]> Prebiotic effects of oligosaccharides extract from palm kernel expeller (OligoPKE) on Salmonella typhimurium were investigated in chicks in two experiments. Results of the first experiment showed that OligoPKE reduced the colonization of Salmonella typhimurium in the cecum and increased the immunoglobulin A (IgA) production in the blood and jejunum. The second experiment further investigated the prebiotic efficacy of dietary supplementation of OligoPKE on three levels of Salmonella typhimurium infection (1.0 x 104 Colony-forming unit (CFU)/mL; 1.0 x 106 CFU/mL and 1.0 x 108 CFU/mL) in chicks. OligoPKE reduced the colonization of Salmonella in the medium and high levels of infection. IgA level in serum and jejunum content increased significantly in all the three levels of infection when chicks received OligoPKE in their diet. Interleukin 8, and 10; interferon-α; and tumour necrosis factor genes were up-regulated in the jejunum of the infected chicks, and OligoPKE down-regulated these gene expressions. Results of the current study indicated that OligoPKE, an oligosaccharides extract from palm kernel expeller, is capable of reducing colonization of Salmonella typhimurium in young chicks, and boosted their immunity. <![CDATA[<b>Effect of feeding regime on the performance and blood parameters of male and female broiler chickens</b>]]> The aim of the present study was to evaluate the effect of feeding regime on changes in growth, mortality, carcass composition, and blood parameters of male and female broiler chickens during feed restriction and the realimentation period. In the experiment, males and females were split into three groups: i) ADL, a group fed ad libitum during the entire experiment; ii) R80, a group that received 80% ad libitum; and iii) R65, a group that received 65% ad libitum. Restriction was applied in both groups from 7 to 14 days old. Daily weight gain (DWG) was reduced significantly in males to 35% in R80 and 39% in R65, and in females to 40% in R80 and 45% in R65. Insignificant compensatory growth occurred in the last week of the growing period. Feed restriction reduced mortality, with a higher mortality reduction in the R65 groups. There was no effect of feed restriction on dressing percentage or thigh yield. However, breast yield was lower and abdominal fat yield was higher in restricted birds. There was a minor effect of feeding regime on blood biochemical and haematological measurements. Males showed significantly higher compensatory growth, feed intake, mortality and thigh yield than females, but dressing percentage and abdominal fat levels were significantly higher in females. Blood total protein and urea concentration were affected by the interaction between sex, group and age.