Yeast hydrolysate product enhances ruminal fermentation in vitro

Effect of Dietary Supplementation of Hydrolyzed Yeast on Growth Performance, Digestibility, Rumen Fermentation, and Hematology in Growing Beef Cattle

This experiment was conducted to assess the effect of hydrolyzed yeast (HY) on growth performance, nutrient digestibility, rumen fermentation, and hematology in growing crossbred Bos indicus cattle. Twenty crossbred beef cattle with an initial body weight (BW) of 142 ± 12 kg were randomly assigned to one of four treatments for 90 d in a randomized complete block design (RCBD) having five blocks based on a homogenous subpopulation of sex and BW. Cattle were fed with a total mixed ration (TMR) and supplemented with HY at 0, 1, 2, and 3 g/kg dry matter (DM), respectively. Supplementation with the HY did not change average daily gain (ADG), dry matter intake (DMI), and gain to feed ratio (G:F) (p ≥ 0.06). The addition of HY did not adversely affect nutrient intake (p ≥ 0.48), while the digestibility of crude protein (CP) increased quadratically (p= 0.03) in the cattle receiving HY. The addition of HY did not affect rumen pH, but NH3-N concentration increased linearly (p = 0.02) in the cattle. The total volatile fatty acid (total VFA) increased quadratically (p= 0.03) when cattle were fed with HY supplementation. The proportion of acetate decreased cubically (p= 0.03) while propionate increased cubically (p= 0.01), resulting in a decrease in the acetate to propionate ratio (p= 0.01) when cattle were fed with HY supplementation. In addition, acetate was the lowest, but total VFA and propionate were the highest in cattle fed the HY at 2 g/kg DM. Butyrate increased cubically (p = 0.02) with the addition of HY. The protozoal and fungal populations were similar among treatments (p ≥ 0.11), but the bacterial population increased linearly (p < 0.01) with the addition of HY. Supplementation of HY did not influence blood urea nitrogen (BUN), red blood cells (RBC), hemoglobin, hematocrit, white blood cells (WBC), lymphocytes, or eosinophils (p≥ 0.10). However, monocytes and neutrophils increased linearly (p = 0.04 and p = 0.01, respectively) by HY supplementation. In conclusion, supplementation of HY at 2 g/kg DM promotes CP digestibility, rumen fermentation efficiency, and hematology but does not affect the growth performance of growing beef cattle.

Bioconversion of agro-industrial residues as a protein source supplementation for multiparous Holstein Thai crossbreed cows

The purpose of this field study was to compare the effects of top-dressing tropical lactating cows with soybean meal (SBM) or citric waste fermented yeast waste (CWYW) on intake, digestibility, ruminal fermentation, blood metabolites, purine derivatives, milk production, and economic return. Sixteen mid-lactation Thai crossbreeds, Holstein Friesian (16.7 ± 0.30 kg/day milk yield and 490 ± 40.0 kg of initial body weight) were randomly allocated to two treatments in a completed randomized design: SBM as control (n = 8) or CWYW (n = 8). The feeding trial lasted for 60 days plus 21 days for treatment adaptation. The results showed that total dry matter intake, nutrient intake, and digestibility did not (p>0.05) differ between SBM and CWYW top-dressing. Ruminal pH and the protozoal population did not (p>0.05) differ between SBM and CWYW top-dressing. After 4 hours of feeding, CWYW top-dressing showed greater ammonia nitrogen, plasma urea nitrogen, and bacterial population compared with the top-dressing of SBM. Volatile fatty acids and purine derivatives were not different (p>0.05) between SBM and CWYW top-dressing. For milk urea nitrogen, there was a greater (p<0.05) and somatic cell count was lower (p<0.05) for cows fed the CWYW top-dress compared to cows fed the SBM top-dress. The cost of the top-dress and total feed cost were less (p<0.05) for CWYW compared to SBM top-dressing, at 0.59 vs 1.16 US dollars/cow/day and 4.14 vs 4.75 US dollars/cow/day, respectively. In conclusion, CWYW could be used as an alternative protein source to SBM without having a negative impact on tropical lactating cows.

Evaluating the effects of high-oil rapeseed cake or natural additives on methane emissions and performance of dairy cows

We evaluated the potential of feeding high-oil rapeseed cake or natural additives as rumen modifiers on enteric methane (CH₄) emissions, nutrient utilization, performance, and milk fatty acid (FA) profile of dairy cows. Eight Nordic Red dairy cows averaging (mean ± SD) 81 ± 21 d in milk and 41.0 ± 1.9 kg of milk yield at the beginning of the study were randomly assigned to a replicated 4 × 4 Latin square design with 21-d periods. Treatments comprised grass silage-based diets (45:55 forage to concentrate ratio on dry matter basis) including (1) control containing 19.3% rapeseed meal (CON), (2) CON with full replacement of rapeseed meal with rapeseed cake (RSC), (3) supplementation of CON with 50 g/d of yeast hydrolysate product plus coniferous resin acid-based compound (YHR), and (4) supplementation of CON with 20 g/d of combination of garlic-citrus extract and essential oils in a pellet (GCE). Apparent total-tract digestibility was measured using total collection of feces, and CH₄ emissions were measured in respiratory chambers on 4 consecutive days. Data collected during d 17 and 21 in each period were used for ANOVA analysis using a mixed model. Treatments did not affect dry matter intake (DMI), whereas feeding RSC increased crude protein and ether extract digestibility compared with the other diets. Emissions of CH₄ per day, per kilogram of DMI, and per kilogram of energy-corrected milk, and gross energy intake were lower for RSC compared with other diets. We found no effect of YHR on daily CH₄ emissions, whereas CH₄ yield (g of CH₄/kg of DMI or as percentage of gross energy intake) decreased with GCE compared with CON. Treatments did not influence energy balance. Further, RSC reduced the proportion of N intake excreted in feces, and YHR improved N balance compared with CON diet. Feeding RSC resulted in greatest yields of milk and energy-corrected milk, and feed efficiency. Relative to the CON diet, RSC decreased saturated FA by 10% in milk fat by increasing cis-monounsaturated FA but also increased the proportion of trans FA. Proportion of odd- and branched-chain FA increased with GCE and YHR compared with CON. We conclude that replacing rapeseed meal by rapeseed cake decreased CH₄ emissions, whereas YHR or GCE had no effect on CH₄ emissions in this study.

Effect of Hydrolyzed Yeast Administration on Faecal Microbiota, Haematology, Serum Biochemistry and Cellular Immunity in Healthy Dogs

Fungal microorganisms are regularly found in the gastrointestinal tract of healthy and diseased dogs especially from the phyla Ascomycota and Basidiomycota; however, it is necessary to better understand their role in host health. One of the most commonly studied yeast species in humans or animals is Saccharomyces cerevisiae especially in its live cell form. Scarce knowledge on its hydrolysate product effects in dogs forced us to test diet supplemented with hydrolyzed brewery S. cerevisiae (at a dose 0.3% of the diet) for 14 days to healthy adult dogs. Twenty German Shepherds were randomly divided into 2 groups: control and experimental, ten dogs in each. The experiment lasted 42 days (blood and faeces sample collection at days 0, 14, 28 and 42). The results of this straighforward experiment showed significant increase in the abundance of bifidobacteria (day 14), lactic acid bacteria (day 42) and clostridia (day 42). The faecal pH was significantly increased at day 28. In blood serum, the concentration of triglyceride and cholesterol decreased (day 42) while activities of alanine aminotransferase (at day 14) and aspartate aminotransferase significantly increased (at days 28 and 42). Activities of these enzymes were above reference range top in 7 dogs (ALT) and 4 dogs (AST). Haematological paramaters and activity of phagocytes as well as on percentage of lymphocyte subsets CD4⁺, CD8⁺, CD4⁺CD8⁺ and CD21⁺ were not changed during the experiment. The important point of these results is their onset mostly in the post-supplementation period. The observation of some unexpected effects emphasizes the need for reassessment to use yeasts products for dogs but further studies using different doses are necessary.

Maximising the benefits of pelleting diets for modern broilers

The importance of feeding pelleted feed to broilers is no longer questionable. However, the extent of performance benefits associated with feeding pelleted diets to broilers depends on available nutrient intake, which, in turn, is influenced by grain type, processing variables such as conditioning temperature, feed texture and birds’ digestive-tract development. The current practice of a high degree of feed processing, especially fine grinding, and ad libitum feeding do not support the normal development and functionality of the foregut. Incorporation of structural components in contemporary broiler diets can impart benefits to the birds’ digestive system. Benefits from pelleting could be improved by using diets with lesser nutrient densities and a pellet-appropriate approach is suggested for broiler-feed formulation. In this strategy, dietary nutrient density must be considered to maximise the benefits from the steam-pelleting process. Identification of the optimum density to be used will warrant further research that also involves the economics. On the basis of available evidence, it is reasonable to assume that nutrient requirements of modern broilers may depend on the feed form and there is a need to determine the nutrient requirements of broilers using pelleted diets.