Do live or inactive yeasts improve cattle ruminal environment?

Abstract

Ruminants Full-length research article Do live or inactive yeasts improve cattle ruminal environment? ABSTRACT-This research was conducted to investigate the effect of live and inactive sugarcane yeast on beef cattle voluntary intake, apparent digestibility of nutrients, ruminal pH, volatile fatty acids (VFA) concentrations, and ruminal ammonia. Five rumen-cannulated Nellore heifers were distributed in a 5×5 Latin square design, with five experimental periods of 15 days, with seven days for adaptation to the additives and the remaining days for data records and sampling. Total mixed ration (TMR) was composed by corn silage (20%) and concentrate (80%) based on corn and soybean meal. Five treatments were evaluated: without additive use (negative control; NC); chemical buffer addition-0.71% in concentrate DM of sodium bicarbonate and 0.18% of magnesium oxide (positive control, PC); 10 g/day live yeast (LY); 15 g/day of inactive yeast (IY15); and 30 g/day of inactive yeast (IY30). Sugarcane yeasts were directly infused in rumen immediately after morning and afternoon feed supply. Feed additives did not affect voluntary intake, nutrient digestibility, and sorting behavior of animals. However, heifers from all treatments presented preferential intake of fibrous fraction of diet, especially those from NC and IY15. Nitrogen balance, VFA concentrations, and blood parameters were not influenced as well. Sodium bicarbonate and magnesium oxide led to greater ruminal pH than yeast, and IY15 presented greater pH than IY30. Ruminal ammonia was increased by the use of additives. Active and inactive yeasts are not recommended as feed additives for bovines fed diets with 80% of concentrate since it allows animals to select fibrous particles from TMR, and no representative gain in ruminal parameters and digestibilities are guaranteed.

Effects of substituting agro-industrial by-products for soybean meal on beef cattle feed utilization and rumen fermentation

“…A increase in the concentration of NH 3 -N in the rumen is brought on by the high urea content of the CWYW and the quick hydrolysis of NH 3 -N by microbial enzymes 29 , 30 . In addition, changes in the proteolytic ruminal microorganism population and microbial disintegration of yeast cells into amino acids and NH 3 -N likely contributed to increased ruminal NH 3 -N in CWYW-fed animals 31 , 32 . Similarly, Suriyapha et al 2 found that the in vitro ruminal NH 3 -N concentration was increased when higher levels of CWYW replaced SBM.…”

Utilization of Yeast Waste Fermented Citric Waste as a Protein Source to Replace Soybean Meal and Various Roughage to Concentrate Ratios on In Vitro Rumen Fermentation, Gas Kinetic, and Feed Digestion

“…Thus, substantial increases in NH 3 -N concentrations occur in response to the microbial degradation of yeast cells [48,49]. Additionally, it could be due to the ability to provide stimulatory factors and even protein [50,51] to ruminal bacteria, or by changing in the abundance of microbes with proteolytic activity [52].…”

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

“…The greater ruminal NH 3 -N concentration at 4 h after feeding and the greater mean value for CWYW top-dressing compared to SBM top-dressing could be due to the greater CP content and CP digestibility of CWYW compared to SBM. Greater CP digestibility may have occurred as a result of the microbial disintegration of yeast cells [ 35 ] because of changes in the number of ruminal microorganisms with proteolytic activity [ 36 ] or to the ability to supply substances as stimulants, including protein, to bacteria in the rumen [ 37 , 38 ]. Another effect is the high level of NPN-urea in the CWYW, which causes increased levels of urea-N in the diet and the fast hydrolysis of NPN-urea into ruminal NH 3 -N by microbial enzymes, causing an elevation in ruminal NH 3 -N concentration [ 28 , 39 ].…”

“…number of ruminal microorganisms with proteolytic activity [36] or to the ability to supply substances as stimulants, including protein, to bacteria in the rumen [37,38]. Another effect is the high level of NPN-urea in the CWYW, which causes increased levels of urea-N in the diet and the fast hydrolysis of NPN-urea into ruminal NH 3 -N by microbial enzymes, causing an elevation in ruminal NH 3 -N concentration [28,39].…”