Fibrolytic enzymes improving in vitro rumen degradability of tropical forages.

During specific times of the year, especially dry seasons, tropical forages typically have poor nutritional value due to high contents of neutral and acid detergent fibres, and low crude protein in their composition, which may reduce productivity of ruminant livestock production and lead to increased enteric methane (CH4 ) emissions per unit of generated product in forage-bases systems. In order to increase fibre degradability and the efficiency of energy utilisation from low-quality forages, exogenous fibrolytic enzymes have been studied. In this assay, we evaluated the effects of increasing dose levels of fibrolytic enzymes extract (FEE) produced by Trichoderma reesei on in vitro rumen organic matter degradability, fermentation parameters, total gas and CH4 production of tropical forages. Forage samples were analysed for their bromatological composition, and enzyme activity from FEE was performed for xylanase and endoglucanase. The in vitro gas production technique was used in a 5 × 3 factorial arrangement with five FEE dose levels (0, 5, 50, 500 and 5,000 µl) and three substrates (Cynodon spp., Panicum maximum and Cenchrus ciliaris L.). The highest dose level of FEE increased degradability, total gas and CH4 production in all substrates (p < .05). Butyrate concentration also increased while acetate:propionate ratio and pH decreased with the addition of FEE (p < .05). These results indicated that the use of fibrolytic enzymes can be a reliable strategy to improve degradability of low-quality forages, contributing to the sustainability and intensification of livestock production in tropical countries.

Trichostrongylus colubriformis infection: Impact on digesta passage rate and lamb performance.

In this study we aimed to evaluate the effect of Trichostrongylus colubriformis infection on digesta passage rate, rumen fermentation and lamb performance. Eighteen three-month-old Santa Ines castrated male lambs (16.9 ±â€¯1.43 kg of body weight) were randomly distributed in two experimental treatments: Infected with T. colubriformis (I, n = 9) and Uninfected (U, n = 9). The I lambs received a total of 45,000 L3 larvae of T. colubriformis (5,000 infective larvae, three times per week for three weeks). Daily feed intake was assessed using the I lambs as a reference for their respective pairs on the U group (pair-fed). Weight, body condition score and faeces (stool) samples were obtained every 15 days for 75 days. In both treatments, faecal egg count (FEC), digesta passage rate, rumen fermentation parameters, protozoa count and short chain fatty acids (SCFA) were evaluated. The lambs presented moderate infection (FEC = 620). The retention time of the digesta in the rumen-reticulum segment was lower (P < 0.05) in I lambs. The I lambs presented no inappetence, however, lower concentrations of total SCFA and butyrate, while higher acetate concentration were observed in these lambs (P < 0.05). The present findings highlight that T. colubriformis infection decreased the retention time (solid and liquid content) of the digesta in the rumen-reticulum, as well as negatively affected lamb growth.

Probiotic mitigates the toxic effects of potassium dichromate in a preclinical study: a randomized controlled trial.

BACKGROUND: The present study aimed to evaluate the nutritional, physiological and biochemical effects of dietary supplementation of an association of probiotic bacteria in rats intoxicated with chromium (VI). Ninety-six male rats, recently weaned, were randomly divided into eight groups (n = 12): Control, DK12, DK24 and DK36 (0, 0.12, 0.24 and 0.36 g kg-1 of K2 Cr2 O7 incorporated in the basal feed, respectively) and groups Prob, DK12 + Prob, DK24 + Prob and DK36 + Prob received a progressive dose of 0, 0.12, 0.24 and 0.36 g kg-1 of K2 Cr2 O7 incorporated in the basal feed and supplemented with 0.02 g kg-1 of an association of probiotic bacteria (Lactobacillus acidophilus, Enterococcus faecium, Bifidobacterium thermophilum and Bifidobacterium longum). RESULTS: After 90 days, we observed significant (P < 0.05) and dose-dependent alterations from incorporation of increasing doses of chromium (VI) related to nutritional, physiological and biochemical parameters. These changes were attenuated (P < 0.05) with probiotic supplementation. CONCLUSION: Supplementation with probiotics in the diet beneficially modified the nutritional and physiological parameters, as well as hepatic, renal, glycemic and lipid profiles, of animals intoxicated with increasing doses of K2 Cr2 O7 . © 2018 Society of Chemical Industry.