Comparison of non-encapsulated and encapsulated active dried yeast on ruminal pH and fermentation, and site and extent of feed digestion in beef heifers fed high-grain diets

Regulation of glycose and lipid metabolism and application based on the colloidal nutrition science properties of konjac glucomannan: A comprehensive review

The physicochemical properties of dietary fiber in the gastrointestinal tract, such as hydration properties, adsorption properties, rheological properties, have an important influence on the physiological process of host digestion and absorption, leading to the differences in satiety and glucose and lipid metabolisms. Based on the diversified physicochemical properties of konjac glucomannan (KGM), it is meaningful to review the relationship of structural characteristics, physicochemical properties and glycose and lipid metabolism. Firstly, this paper bypassed the category of intestinal microbes, and explained the potential of dietary fiber in regulating glucose and lipid metabolism during nutrient digestion and absorption from the perspective of colloidal nutrition. Secondly, the modification methods of KGM to regulate its physicochemical properties were discussed and the relationship between KGM's molecular structure types and glycose and lipid metabolism were summarized. Finally, based on the characteristics of KGM, the application of KGM in the main material and ingredients of fat reduction food was reviewed. We hope this work could provide theoretical basis for the study of dietary fiber colloid nutrition science.

Active dry yeast supplementation benefits ruminal fermentation, bacterial community, blood immunoglobulins, and growth performance in young dairy goats, but not for intermittent supplementation

This study evaluated the effects of active dry yeast (ADY) supplementation and supplementation strategies on ruminal fermentation, bacterial community, blood metabolites, and growth performance in young dairy goats. Sixty young female Guanzhong dairy goats of similar age (4.00 ± 0.50 months) and BW (19.65 ± 0.41 kg) were randomly divided into 3 groups (n = 20): (1) basal diet group (CON); (2) basal diet continuously supplemented with 3.0 g/goat per day commercial ADY (a proprietary strain of Saccharomyces cerevisiae with 5.0 × 10⁹ cfu/g) group (CSY); (3) basal diet with intermittently supplemented ADY group (ISY; 5 d supplementation with ADY at 4.5 g/goat per day following 5 d of no supplementation). The experiment lasted 67 d with the first 7 d as an adaptive period. Rumen fluid and blood samples were collected bi-weekly. Data were analyzed using the MIXED procedure combined with the SLICE option in SAS. Specific orthogonal contrasts of ADY vs. CON and CSY vs. ISY were also analyzed. During the experimental period, ADY supplementation resulted in greater DMI (P = 0.03), ruminal acetate proportion (P < 0.01) and acetylesterase activity (P = 0.01), and blood contents of glucose (P = 0.01) and IgM (P = 0.02) and tended to have greater ADG (P = 0.05) and paunch girth (P = 0.06) than the CON, despite the propionate proportion (P = 0.03) and contents of total protein (P = 0.04) and IgA (P = 0.03) being lower. The lower ruminal NH₃-N (P < 0.01) and blood urea nitrogen (P = 0.07) contents indicated greater nitrogen utilization with ADY supplementation. ADY supplementation showed persistent effects after it was stopped because the BW at 12 months of age (P = 0.03) and birth weight of lambs (P = 0.02) were greater than the CON. However, the ISY did not show those benefits and had significantly lower relative abundances of fiber-degrading related bacteria than the CSY. In conclusion, ADY supplementation, especially continuously supplemented, may enhance ADG and ADG:DMI ratio by improving DMI, ruminal cellulolytic bacteria abundance and enzyme activity, nitrogen utilization, and immune status. These findings provide a theoretical basis for the rational application of ADY and have important practical implications for the design of nutritional strategies in growing dairy goats.

Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 6: Macrolides: tilmicosin, tylosin and tylvalosin

The specific concentrations of tilmicosin, tylosin and tylvalosin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield, were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tilmicosin and tylosin, whilst for tylvalosin no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these three antimicrobials.

Effect of non-encapsulated and encapsulated active dried yeast on blood cell count, blood metabolites, and immune response of finishing beef heifers

A study was conducted to evaluate whether encapsulated active dried yeast (EDY), compared with non-protected active dried yeast (ADY) or antibiotics (ANT), improved immune response and blood metabolites of finishing beef heifers. Blood urea nitrogen was lower (P < 0.05) with supplemented ADY and mixture of ADY and EDY (MDY) compared with control. Supplementation of MDY also resulted in lower (P < 0.05) red blood cell distribution width than control. Lipopolysaccharide-binding protein was less (P < 0.05) for EDY than control, ANT, and ADY as well as cytokine concentration of interleukin-6 was less (P < 0.05) for MDY versus control.

Effects of dry yeast supplementation on growth performance, rumen fermentation characteristics, slaughter performance and microbial communities in beef cattle

This study aimed to investigate the effects of active dry yeast (ADY) on growth performance, rumen microbial composition and carcass performance of beef cattle. Thirty-two finishing beef cattle (yak ♂ × cattle-yaks ♀), with an average body weight of 110 ± 12.85 kg, were randomly assigned to one of four treatments: the low plane of nutrition group (control), low plane of nutrition group + ADY 2 g/head daily (ADY2), low plane of nutrition group + ADY 4 g/head daily (ADY4) and the high plane of nutrition group (HPN). Supplementation of ADY increased average daily gain compared to the control group. The neutral detergent fiber and acid detergent fiber apparent digestibility in HPN group was greater than that in control group. The propionic acid concentration in the rumen in ADY2, ADY4, and HPN groups was greater than that in control group. The Simpson and Shannon indexes in control and HPN groups were higher than that in ADY4 group. At the phylum level, the relative abundance of Firmicutes in the HPN group was higher than that in ADY4 group. The relative abundance of Ruminococcaceae UCG-002 in ADY4 group was higher than that in control and HPN groups. In conclusion, supplementation ADY 4 g/head daily shift the rumen microbial composition of beef cattle fed low plane of nutrition to a more similar composition with cattle fed with HPN diet and produce the similar carcass weight with HPN diet.HighlightsThe ADY can improve the utilization of nitrogen and decrease the negative impact on the environment in beef cattle.Cattle fed low plane of nutrition diet supplemented with ADY 4 g/head daily increased growth performance.Supplementation ADY 4 g/head daily in low plane of nutrition diet might be produced comparable carcass weight to HPN diet.

Fecal bacterial community of finishing beef steers fed ruminally protected and non-protected active dried yeast

Our previous study suggested that supplementation of high-grain diets with ruminally protected and non-protected active dried yeast (ADY) may potentially reduce manure pathogen excretion by feedlot cattle. We hypothesized that feeding ruminally protected ADY might change the fecal bacterial community of finishing cattle. The objective of this study was to investigate the effects of feeding ruminally protected and non-protected ADY to finishing beef steers on their fecal bacterial community. Fresh fecal samples were collected on day 56 from 50 steers fed one of five treatments: 1) control (no monensin, tylosin, or ADY), 2) antibiotics (ANT, 330 mg monensin + 110 mg tylosin·steer-1d-1), 3) ADY (1.5 g·steer-1d-1), 4) encapsulated ADY (EDY; 3 g·steer-1d-1), and 5) a mixture of ADY and EDY (MDY; 1.5 g ADY + 3 g EDY·steer-1d-1). Bacterial DNA was extracted from fecal samples and sequenced using a MiSeq high-throughput sequencing platform. A total number of 2,128,772 high-quality V4 16S rRNA sequences from 50 fecal samples were analyzed, and 1,424 operational taxonomic units (OTU) were detected based on 97% nucleotide sequence identity among reads, with 769 OTU shared across the five treatments. Alpha diversity indices, including species observed, Chao estimate, abundance-based coverage estimator, Shannon, Simpson, and coverage, did not differ among treatments, and principal coordinate analysis revealed a high similarity among treatments without independent distribution. Bacteroidetes and Firmicutes were dominant phyla in the fecal bacterial community for all treatments, with a tendency (P < 0.10) for greater relative abundance of Bacteroidetes but lesser Firmicutes with ANT, EDY, and MDY compared with control steers. Prevotella was the dominant genus in all treatments and steers supplemented with ANT, EDY, and MDY had greater (P < 0.05) relative abundance of Prevotella than control steers, but lesser (P < 0.03) relative abundance of Oscillospira. No differences between ADY and control were observed for the aforementioned variables. Fecal starch contents were not different among treatments, but the relative abundance of Bacteroidetes, as well as Prevotella at genera level, tended (P < 0.06) to be positively correlated to fecal starch content. We conclude that supplementing ruminally protected or non-protected ADY or ANT had no effect on diversity and richness of fecal bacteria of finishing beef cattle, whereas feeding protected ADY or ANT to finishing beef steers altered the dominant fecal bacteria at phylum and genus levels. Therefore, supplementation of ruminally protected ADY may potentially improve intestinal health by stimulating the relative abundance of Prevotella.

Screening of live yeast and yeast derivatives for their impact of strain and dose on in vitro ruminal fermentation and microbial profiles with varying media pH levels in high-forage beef cattle diet

BACKGROUND

Yeast products showed beneficial effects with respect to stabilizing ruminal pH, stimulating ruminal fermentation and improving production efficiency. Batch cultures were conducted to evaluate the effects of yeast products on gas production (GP), dry matter disappearance (DMD) and fermentation characteristics of high-forage substrate. The study was a two media pH (5.8 and 6.5) × five yeasts (three live yeasts, LY: LY1, LY2, LY3; two yeast derivatives, YD: YD4, YD5) × four dosages factorial arrangement, with monensin (Mon) assigned as a positive control.

RESULTS

Greater (P < 0.01) GP, DMD, volatile fatty acid (VFA) concentration, ratio of acetate to propionate (A:P) and copy numbers of Fibrobacter succinogenes and Ruminococcus flavefaciens were observed at pH 6.5 than at pH 5.8. The GP kinetics, DMD, VFA concentration, A:P and NH₃ -N concentration differed (P < 0.05) among yeasts but varied with media pH or yeast dosages. Increasing doses of LY3 linearly increased DMD (P < 0.04) and VFA concentration (P < 0.001) at media pH 5.8. The DMD linearly (P < 0.02) increased with increased addition of YD4 (pH 6.5) and YD5 (pH 5.8) and the ratio of A:P linearly decreased (P < 0.01) with the addition of YD4 or YD5 at pH 5.8. Overall greater (P < 0.05) GP, A:P (pH 5.8) and DMD (pH 6.5) were observed with yeast products than with Mon.

CONCLUSION

LY3 appeared to be an interesting candidate for improving rumen digestibility and fermentation efficiency, particularly at low media pH. YD4 or YD5 improved fermentation efficiency and can be potentially fed as an alternative to Mon. © 2019 Her Majesty the Queen in Right of Canada Journal of the Science of Food and Agriculture © 2019 Society of Chemical Industry.

Using ruminally protected and nonprotected active dried yeast as alternatives to antibiotics in finishing beef steers: growth performance, carcass traits, blood metabolites, and fecal Escherichia coli

The objective of this study was to evaluate the effects of supplementing the diet of finishing beef steers with active dried yeast (ADY) in ruminally protected and nonprotected forms on growth performance, carcass traits, and immune response. Seventy-five individually-fed Angus steers (initial body weight (BW) ± SD, 448 ± 8.4 kg) were assigned to a randomized complete design with 5 treatments: 1) control (no monensin, tylosin, or ADY), 2) antibiotics (ANT, 330 mg monensin + 110 mg tylosin·steer-1d-1), 3) ADY (1.5 g·steer-1d-1), 4) encapsulated ADY (EDY; 3 g·steer-1d-1), and 5) a mixture of ADY and EDY (MDY; 1.5 g ADY + 3 g EDY·steer-1d-1). Active dried yeast with 1.7 × 1010 cfu/g was encapsulated in equal amounts of ADY and capsule materials (stearic acid and palm oil). Steers were fed a total mixed ration containing 10% barley silage and 90% barley-based concentrate mix (dry matter [DM] basis). The ANT, ADY, and EDY were top-dressed daily to the diet at feeding. Intake of DM, final BW, averaged daily gain (ADG), and gain-to-feed ratio (G:F) were unaffected by ADY or EDY. Carcass traits including hot carcass weight (HCW), dressing percentage, marbling score and quality grade did not differ among treatments, although fewer severely abscessed livers were observed (P < 0.05) with ADY and MDY compared with the other treatments. Plasma urea N tended (P < 0.10) to be greater in steers fed ANT, ADY, or EDY on day 56 and 112, while glucose remained stable in all treatments except greater (P < 0.02) plasma glucose occurred in steers fed MDY on day 112. Serum nonestrified fatty acid (NEFA) was unaffected by ADY or EDY, but it was greater (P < 0.03) in steers fed ANT compared with control. Plasma haptoglobin (Hp) and serum amyloid A (SAA) were affected by yeast supplementation on day 112, with greater (P < 0. 01) Hp in steers fed ADY, EDY, or MDY and lesser (P < 0.01) SAA in steers fed EDY and MDY than control. Lipopolysaccharide binding protein concentrations were greater (P < 0.01) in steers fed EDY and MDY on day 56. Supplementing with ADY (protected or nonprotected) or ANT had no effect on fecal IgA contents on day 56 and 112. Steers fed yeast (EDY or MDY) tended (P < 0.10) to have fewer fecal Escherichia coli counts than the control and ANT on day 56 and 112. These results indicate that feeding ADY to feedlot cattle may exhibit antipathogenic activity that conferred health and food safety beneficial effects including reduced liver abscess and potentially pathogen excretion, thus yeast may be an alternative to in-feed antibiotics in natural beef cattle production systems.

Influence of yeast culture and feed antibiotics on ruminal fermentation and site and extent of digestion in beef heifers fed high grain rations1

The study objective was to investigate the effects of site of delivering Saccharomyces cerevisiae fermentation product (SCFP) on ruminal pH and fermentation characteristics, and the site and extent of feed digestion in the digestive tract of beef heifers fed high-grain diets. Examining the ruminal and postruminal effects of SCFP is important for understanding the potential use of SCFP as an alternative for current industry-standard antibiotics used in beef cattle rations. Five beef heifers (initial BW = 561 ± 11.7 kg) equipped with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design with 28-d periods, including 21 d for adaption and 7 d for data collection. Five treatments were as follows: 1) control diet that contained 10% barley silage and 90% barley concentrate mix (DM basis); 2) control diet supplemented with antibiotics (ANT; 330-mg monensin/d and 110-mg tylosin/d per head); 3) ruminal (top dress) delivery of SCFP (rSCFP; NaturSafe, Diamond V, 18-g SCFP/d); 4) duodenal delivery of SCFP (dSCFP; 18-g SCFP/d, via duodenal cannula); and 5) a combination of rSCFP and dSCFP (rdSCFP; 18-g rSCFP and 18-g dSCFP). Intake of DM tended (P < 0.10) to be greater by heifers fed rdSCFP than those fed control, ANT and rSCFP diets. Minimum ruminal pH was greater (P < 0.05) with rSCFP than control and rdSCFP treatments. The duration of ruminal pH < 5.6 tended (P < 0.10) to be less with rSCFP than control and ANT. Heifers fed the rSCFP diet had greater (P < 0.03) protozoa counts and proportion of acetate than the other treatments. Nutrient flows to the duodenum did not differ (P > 0.19), whereas the amount of truly fermented OM was greater (P < 0.03) with rdSCFP than the other treatments. Ruminal OM digestibility was highest with rSCFP and rdSCFP, intermediate with dSCFP and ANT, and lowest with control (P < 0.03). Intestinal digestibility was similar among treatments. As a result, total tract digestibility of OM (P < 0.07) and NDF (P < 0.01) was greater with rSCFP and rdSCFP than control and ANT. Fecal IgA concentration was highest with ANT, intermediate with dSCFP and rdSCFP, and lowest with control and rSCFP (P < 0.03). These results demonstrate that feeding SCFP improved stability of ruminal pH and digestibility of OM and NDF. Delivery of SCFP to the duodenum appeared to have little effect on nutrient digestibility but improved intestinal immune response. Feeding SCFP performed better or at least equal to antibiotics currently used in beef cattle rations and could be a natural alternative for beef cattle production.