Effects Of Live Yeast Supplementation Research Articles

400 Effects of Live Yeast Supplementation on Growth Performance and Biomarkers of Metabolism and Inflammation in Finishing Pigs during Heat Stress.

400 Effects of Live Yeast Supplementation on Growth Performance and Biomarkers of Metabolism and Inflammation in Finishing Pigs during Heat Stress.

101 Effects of Live Yeast Supplementation on Complete Blood Cell Count and Febrile Responses in Heifers after Viral-Bacterial Respiratory Challenge.

Experiment objectives were to determine if live yeast (LY) supplementation would impact immune and febrile responses to a viral-bacterial (VB) respiratory challenge. Thirty-eight crossbred Angus heifers (230 ± 16.4 kg) were allocated within a 2X2 factorial arrangement: Factor 1= roughage-based diet with or without LY (Saccharomyces cerevisiae boulardii I-1079, 62.5 gr/hd/d), Factor 2= VB, intranasal administration of bovine herpesvirus-1 (BHV-1, 2x108, PFU) and broncho-selective endoscopic inoculation with Mannheimia haemolytica (MH, 5.4x1010, CFU) 3 d post or intranasal saline administration followed by inoculation with phosphate buffer solution (PBS). Treatment arrangements were housed in separate pens (2 pens / treatment) and group-fed in electronic feedbunks. Heifers were randomized by MH and BHV-1 titer status, and fed their respective diets for 27 d prior to VB challenge on d 0. Thermo-boluses (Medria) measured rumen temperature (RUT) at 5-min intervals and rectal temperature (RT) was measured on d 0, 3–8, 10, 13 and 15. Whole blood samples were collected via venipuncture on d -13, -6, 0, 3–8, 10, 13 and 15 for complete blood count analysis. Data were analyzed using repeated measures in the mixed procedure of SAS with fixed effects of day, diet, VB challenge and their interactions. Animals fed LY exhibited a 16% increase (P=0.02) in neutrophils relative to controls. There were no other differences due to dietary treatment or interactions with day or VB challenge. There was a significant 3-way interaction for monocytes, which peaked on d 4 for VB treatment. LY supplementation increased (P<0.05) the level of monocytes relative to the control, suggesting a greater innate immune response. Viral-bacterial challenge produced nasal lesions that increased with d (P<0.01), reaching a nadir on d 6 with 70% of the naris covered with plaques, and increased (P<0.05) neutrophils on d 3–5 relative to PBS. Viral-bacterial challenge increased RUT (P<0.05) on d 2–7, but decreased RUT on d 9–12 relative to PBS. Rectal temperature was greater for VB heifers (P<0.05) on d 0, 3–6 and RT of PBS heifers never exceeded 40 C. The increase in RT on d 0 was most likely due to increased ambient temperature at time of challenge, as VB heifers were processed after the PBS heifers to avoid contamination. The VB challenge was effective at stimulating immune responses, and RUT was more sensitive than RT for measuring febrile responses. These results indicate that prior LY supplementation altered the leukogram in response to VB challenge, suggestive of increased innate immune response.

Effect of live yeast supplementation on gastric ecosystem in horses fed a high-starch diet

Starch/grain intake has been reported to be at risk for equine gastric lesions of the squamous mucosa (Equine Squamous Gastric Disease – ESGD). Exposition to VFAs and lactic acid, end-products of the fermentation occurring in the gastric ecosystem, can cause ESGD. As in the hindgut, supplementing yeast to high starch/grain diet could increase lactate-utilizing bacteria and thus limit the production of lactic acid and eventually the acidity. The objective of this study was to investigate the effect of two levels of Saccharomyces cerevisiae (Sc47) supplementation on gastric ecosystem in horses fed high-starch diet.Six horses were assigned in a 3*3 Latin square design with three supplement treatments: 10.109 (dose 1) or 10.1010 (dose 10) cfu of zootechnical additive Sc47 per day or a control. Each experimental period lasted 21 days and was separated from the next one by a wash-out period of 21 days. During experimental periods, horses received a 70:30 ratio hay:barley (2.3kg DMI / 100kg BW / day) and 50g per day of the additive. Gastric content samples were collected on day 18 of each experimental period 3h and a half after morning barley meal to measure: pH, bacterial populations (total anaerobic, amylolytic and lactate-utilizing bacteria), and fermentation products (VFAs and lactic acid).The observation of the stomach with the video-endoscope did not reveal any alteration of the squamous gastric mucosa. Total anaerobic bacteria and amylolytic concentrations were lower with Sc47 dose 10 compared to placebo (P = 0.03 and 0.04, respectively). With dose 10 of Sc47, lactate-utilizing bacteria concentrations decreased compare to Sc47 dose 1 (P = 0.03) and placebo (P = 0.004). No treatment effect was observed on total VFAs and lactic acid concentrations. Butyric and valeric acids concentrations showed higher concentration with Sc47 dose 1 compared to other treatments during period 1. Although, the pHs were numerically less acidic with live yeast, they were not significantly modified by the treatment. Globally, there was a dose effect of Sc47 on bacteria concentrations which all decreased or tended to decrease when the level of yeast increased in the diet. Further investigation is required to know whether live yeast supplementation could be part of the strategy to reduce gastric fermentation of starch and thereby help reducing the risk of ESGD.

Changes in gene expression in the rumen and colon epithelia during the dry period through lactation of dairy cows and effects of live yeast supplementation

The objectives of this study were (1) to use endoscopy to collect biopsies from the rumen and colon epithelia to describe changes in gene expression in these 2 tissues as cows move from a dry to a lactation ration and (2) to evaluate the potential influence that supplementation of live yeast could exert on these 2 epithelia. Twenty-one Holstein cows were split into 2 treatments and received either 300 g/d of corn containing 1 × 1010 cfu/d of live yeast (LY; n = 10) or 300 g/d of corn with no supplementation (control; n = 11) starting 21 ± 2.6 d (average ± SD) before until 21 d after calving. At 14 ± 2.6 d before the expected calving date, and exactly at 7 and 21 d after calving, rumen and colon biopsies were obtained from each cow using an endoscope. Total RNA was extracted from rumen and colon tissues, and the expression of IL10, TNFA, TLR4, IL1B, PCNA, MKI67, SGLT1, BAX, CASP3, OCLN, CLDN4, HSPA1A, HSPB1, DEFB1, and MCT1 (the latter only in rumen samples) was quantified by quantitative PCR. Overall, fluctuations in expression of the selected genes in the colon between the 2 stages of production and the 2 treatments were smaller than those found in the rumen. In the rumen epithelium, expression of TLR4 and DEFB1 was greatest before calving, with LY cows having a greater expression of TLR4 than control cows. Similarly, expression of IL10 was greatest in LY cows before calving. Expression of TNFA in the rumen epithelium of control cows was lowest at 21 DIM but in LY cows was kept steady among production stages. The expression of PCNA and MKI67 in the rumen epithelium was greatest at 7 DIM, indicating a high proliferation rate of this epithelium after calving. In the colon mucosa, expression of TLR4 and DEFB1 was greater than in the rumen, and DEFB1 expression was greater in LY cows than in control cows. The use of an endoscope allowed us to study the dynamics of rumen epithelium adaptation to increased supply of concentrate after calving, consisting of increased epithelia remodeling, reduction of the TLR4, and increased IL10 expression. Furthermore, the rumen epithelium of dry cows responded rapidly to live yeast, with changes in the expression of genes involved in the immune response becoming evident after 7 d of exposure to yeast. The expression of genes related to the immune response (mainly TLR4 and DEFB1) in the colon mucosa was greater than in the rumen, and the expression of DEFB1 was further stimulated by live yeast. It is concluded that the use of an endoscope allows the study of gene expression patterns in the rumen and hindgut epithelia. We report marked changes in the rumen wall and more modest changes in the colon when transitioning from a dry to a lactation ration. Furthermore, supplementation of live yeast fostered and increased expression of genes regulating inflammation and epithelial barrier in the rumen, and in the colon it increased the expression of DFEB1 coding for an antimicrobial peptide.

Effect of yeast supplementation on performance, rumination time, and rumen pH of dairy cows in commercial farm environments

The aims of the present study were to evaluate the effects of live yeast supplementation (Vistacell MUCL 39855, AB Vista, Marlborough, UK) on performance, rumination time, and rumen pH on dairy cows in commercial farm environments. Three trials were carried out, the trials lasted 12 (trial 1), 15 (trial 2), and 19 wk (trial 3). In each trial, 14 multiparous Holstein dairy cows were allocated to 2 groups that received (trial 1) a standard diet plus yeast, (trial 2) an acidogenic diet plus yeast, and (trial 3) grazing pasture plus yeast. Milk production, milk chemical characteristics, body weight and body condition score, rumination time, and rumen pH were monitored for each group throughout the 3 trials. No statistically significant differences were observed in any of the 3 trials for any of the recorded variables. In contrast, an effect of time (period or days in milk) on rumen pH was observed in all 3 of the trials, as time spent under the acidotic thresholds increased across the experimental periods; however the differences were not associated with live yeast supplementation. No effect of live yeast supplementation was observed in any of the 3 trials reported. Further research should include studies on animals at different stages of lactation (with emphasis on transition period and early lactation), consuming more challenging diets (higher level of inclusion of concentrates or starch), or under different environments such as grazing of succulent forages. Such studies might be required to elucidate any possible effect of live yeast supplementation of dairy cows when the rumen environment is under challenge.

The Effect of Live Yeast Supplementation on Beef Cattle Performance: A Systematic Review and Meta-Analysis

This meta-analysis evaluates the effects of yeast supplementation (Saccharomyces cerevisiae) on dry matter intake (DMI) and average daily gain (ADG) in beef cattle. The inclusion criteria were complete and randomized trials and supplementation with yeast S. cerevisiae versus no supplementation to measure DMI or ADG. Data were extracted from relevant papers via pre-defined protocols. A meta-analysis of random effects was conducted for each indicator separately including the mean of the control and treated groups. The results were presented with the pooled mean difference (MD), 95% of confidence interval, and I² (percentage of total variation between studies that is due to heterogeneity rather than chance). A total of 12 publications reporting 22 trials conducted in 1,161 cattle were analysed. The heterogeneity between studies was high and ranged from 92 to 99%. No effects were observed in ADG with the inclusion of yeast in the diet (MD = -2.849 g/day, p = 0.492). However, there was a reduction in the DMI (MD = -0.885 kg/day; p = 0.023) despite the high heterogeneity among studies (I2 = 92.4%; p &lt; 0.001). The ADG increased when the forage level in the diet was between 30 and 50% (MD = 641.08 g/day; p = 0.001) and decreased when the level range from 51 to 75% (MD = -2.90 g/day; p &lt; 0.001). In over 60% of the Neutral Detergent Fibre, the use of yeast in the diet decreased the ADG by 406.94 g/day (p = 0.034). Feedlot animals showed a reduction in the DMI (MD = -0.97 kg/day; p = 0.019) if supplemented with yeast. Supplementation with S. cerevisiae in the diet of beef cattle had no effect on ADG; however, it does improve the feed conversion due to the reduction in DMI.

Effects of live yeast supplementation on lipopolysaccharide-induced inflammatory responses in broilers

The effects of supplemental live yeast (LY) on inflammatory responses in broilers challenged with lipopolysaccharide (LPS) were investigated. One-day-old broilers were randomly divided into two treatment groups with two subgroups of each (8 replicate pens; 10 birds/pen) and were fed a basal diet without or with 0.5g/kg of LY (Saccharomyces cerevisiae NCYC 47Hr+, 1.0 × 1010 CFU/g). Birds from each subgroup of the two treatment groups were intra-abdominally injected with LPS (1.5mg/kg of BW) or saline at 21, 23, 25, and 27 d of age. Samples were obtained after 8h of the first injection (d 21) and the last injection (d 27), respectively. Results showed that no treatment differences (P >0.05) were detected in the relative spleen and bursa weights, as well as serum lysozyme activity and ceruloplasmin content regardless of the immunological status. LY addition tended to alleviate (P = 0.097) LPS-induced increase in serum α-acid glycoprotein content on d 27. LPS induced increased (P <0.05) serum nitric oxide content and myeloperoxidase activity on d 21 and 27, however, there was a tendency towards reduced (P <0.10) serum nitric oxide content and myeloperoxidase activity on d 21 in response to LY inclusion. Besides, LY-fed birds had lower (P <0.05) serum nitric oxide content on d 27 relative to the control counterparts. LPS resulted in increased (P <0.05) relative mRNA expression of splenic interleukin-1β on d 21 and 27, but which was lower (P <0.05) in LY-treated birds compared with that in control. In conclusion, dietary supplementation of LY had potential to alleviate LPS-induced inflammation in broilers.

Effect of diet supplementation with live yeast (Saccharomyces cerevisiae) on performance of rabbit does and their progenies

&lt;p&gt;A study was conducted to determine the effect of live yeast supplementation in the diet of rabbit does on their mortality and reproductive performance and the performance of their progeny. A total of 52 cross-bred rabbit does (New Zealand×Californian) were divided into 2 groups differing in diet offered during 2 reproductive cycles and containing (group S; n=26) or not (group C; n=26) 1 g of yeast (Actisaf Sc 47, S.I. LESAFFRE, France)/kg of feed. Natural mating was performed 11 d after kindling and kits were weaned at 28 d of age. Body weight of litters was measured at birth, 21 d and at 28 d of age (weaning). Mortality of kits and rabbit does was monitored daily, and fertility of rabbit does and viability rate of kits at birth were also determined. Weight and litter size at birth and at weaning, litter weight gain during lactation and length of gestation were similar between the 2 groups during the 2 cycles. The mortality of does during the experiment was higher in group C than in group S (27 vs. 4%; P&amp;lt;0.05). Fertility rate of rabbits does and viability rate of kits at birth were higher (P&amp;lt;0.05) in rabbits fed with the supplemented diet than those with the control diet during the second lactation. In the first cycle, kit mortality was lower in S group (15.5%) than the C group (24.7%) during the first 21 d (P&amp;lt;0.05). However, no difference was observed during the second lactation. In conclusion, our results suggest that the inclusion of yeast in the diet of rabbit does could trigger positive effects on the fertility and mortality of rabbit does, as well as on the viability rate of kits at birth.&lt;/p&gt;

Effects of Cultured Yeast Supplementation on Growing Kids Fed With Napier Grass-Concentrate Ration

An In vivo experiment was conducted to assess the effects of live yeast supplementation on the performance of six-month-old young goats. Specifically, it investigated the effects of cultured yeast (Saccharomyces cerevisiae) supplementation of the dry matter intake, growth performance, fluctuation in ruminal fluid pH and rumen bacterial count, as well as on the digestibility of dry matter, organic matter, and crude protein of the napier grass-concentrate ration. The addition of cultured yeast at two grams/ 10 mL distilled water generally increased dry matter intake and weight gain of the young goats, but did not significantly affected bacterial count and ruminal fluid pH. The digestibility of dry matter, organic matter, and crude protein of the napier grass-concentrate ration increased with the addition of cultured yeast. Yeast supplementation of one gram/ 10 mL distilled water enhaced nutrient intake and utilization of the napier grass-concentrate ration.

Effects of live yeast supplementation on mid-lactation dairy cows performances, milk composition, rumen digestion and plasma metabolites during hot season

Fifty-six Holstein cows (36 multiparous and 20 primiparous), that averaged 145±23 days postpartum, were used to investigate the supplementing of live yeast (LY) on productivity during hot summer conditions, from July until August 2010. Cows were fed a control diet with or without 4 g of LY (15×109 CFU/g) per cow daily during a five-week period. Cows were milked three times a day and milk yield was recorded daily. Milk samples were also taken weekly for milk composition analysis. Blood samples and rumen liquor samples were taken in two subsequent days during the last week of the experiment. Milk production, 3.5% fat-corrected milk, and DM intake were similar for cows fed on both diets. A greater milk fat percentage was observed for cows fed LY compared to the control (P<0.05). However, milk urea nitrogen concentration in cows fed LY was lower compared to the control (P<0.01). Cows fed LY had greater blood glucose compared to the control (P<0.01). Blood urea nitrogen was lower for cows fed LY compared to the control (P<0.05). Non-esterified fatty acids, β-hydroxybutyrate (BHB), triglyceride, total protein, and total cholesterol were similar for both diets. The apparent digestibility of NDF was greater for cows fed LY compared to the control (P<0.05). Rumen parameters such as pH, N-NH3, and VFAs were also similar for both treatments. The present results suggested that feeding LY to mid-lactation Holstein cows during heat stress can increase diet cell wall digestibility and improve milk fat percentage.

Effects of live yeast supplementation to gestation and lactation diets on reproductive performance, immunological parameters and milk composition in sows

A study was conducted to determine the effect of live yeast supplementation of sow diets on reproductive performance, immune function, milk composition of sows and performance of their progeny. A total of 47 F1 sows (Yorkshire×Landrace) were allotted to five dietary treatments and two different levels (106 or 107CFU/g of diet) of live yeast (Saccharomyces cerevisiae Sc47) were supplemented during gestation, lactation or both. Treatments were (1) no yeast supplementation during gestation and lactation, (2) gestation—basal diet, lactation—106CFU of yeast/g of diet, (3) gestation—basal diet, lactation—107CFU of yeast/g of diet, (4) gestation—106CFU of yeast/g of diet, lactation—106CFU of yeast/g of diet, (5) gestation—107CFU of yeast/g of diet, lactation—107CFU of yeast/g of diet. Inclusion of live yeast in sow diets did not result in any significant difference in body weight or backfat thickness of sows at 110d of gestation and 21d postpartum. Additionally, reproductive performance of sows, i.e. litter size, total born alive, birth weight and weight gain of progeny, was not influenced by live yeast supplementation (P>0.13). Dietary treatment did not affect average daily feed intake of sows during lactation. Compared with the control, weaning to estrus interval (WEI) was shortened (P<0.01) and percentage of sows in estrus by day 7 after weaning was increased (P<0.01) when sows were fed live yeast contained diet during lactation, regardless of yeast supplementation during gestation. There was no significant difference in milk composition during overall lactation except that IgG concentration in colostrum tended to be higher in the groups receiving live yeast supplementation (P=0.10) compared with the control group, resulting in higher IgG concentration in plasma of piglets at 24h postpartum (P<0.05). These results suggested that the reproductive performance of sows might be improved as shown by reduction of WEI when sows were fed diets supplemented with live yeast. Moreover, the supplementation of live yeast in sow diets could elevate IgG concentration in colostrum and subsequently plasma IgG of piglets.

Repeated acidosis challenges and live yeast supplementation shape rumen microbiota and fermentations and modulate inflammatory status in sheep

This study aimed to investigate the impact of repeated acidosis challenges (ACs) and the effect of live yeast supplementation (Saccharomyces cerevisiae I-1077, SC) on rumen fermentation, microbial ecosystem and inflammatory response. The experimental design involved two groups (SC, n=6; Control, n=6) of rumen fistulated wethers that were successively exposed to three ACs of 5 days each, preceded and followed by resting periods (RPs) of 23 days. AC diets consisted of 60% wheat-based concentrate and 40% hay, whereas RPs diets consisted of 20% concentrate and 80% hay. ACs induced changes in rumen fermentative parameters (pH, lactate and volatile fatty-acid concentrations and proportions) as well as in microbiota composition and diversity. The first challenge drove the fermentation pattern towards propionate. During successive challenges, rumen pH measures worsened in the control group and the fermentation profile was characterised by a higher butyrate proportion and changes in the microbiota. The first AC induced a strong release of rumen histamine and lipopolysaccharide that triggered the increase of acute-phase proteins in the plasma. This inflammatory status was maintained during all AC repetitions. Our study suggests that the response of sheep to an acidosis diet is greatly influenced by the feeding history of individuals. In live yeast-supplemented animals, the first AC was as drastic as in control sheep. However, during subsequent challenges, yeast supplementation contributed to stabilise fermentative parameters, promoted protozoal numbers and decreased lactate producing bacteria. At the systemic level, yeast helped normalising the inflammatory status of the animals.

Canlı Maya İlavesinin Orta veya Yüksek Düzeyde Konsantre Yemle Beslenen Süt İneklerinde Ruminal Parametreler ve Laktasyon Performansı Üzerine Etkisi

Canlı Maya İlavesinin Orta veya Yüksek Düzeyde Konsantre Yemle Beslenen Süt İneklerinde Ruminal Parametreler ve Laktasyon Performansı Üzerine Etkisi

Evaluation of the Effects of Live Yeast Supplementation on Apparent Digestibility of High-Fiber Diet in Mature Horses Using the Acid Insoluble Ash Marker Modified Method

The objective of this study was to evaluate the effects of live yeast (LY) in a high-fiber diet on nutrients digestibility in mature horses. Six Italian Standardbred mares (weight: 544 ± 14 kg; age: 15.30 ± 3.9 years) in a two-period crossover design were fed a basal diet (2.5% body weight [BW]) in a 70:30 forage:concentrate ratio with (LY) or without (CTR) the administration of 4.6 × 1010 colony forming unit (CFU)/d of Saccharomyces cerevisiae (MUCL 39885). An adaptation to the diet of 14 days, and an 18-day administration phase, with fecal collection in the last 3 days were performed for each period. Yeast was top-dressed twice a day during the concentrate meal (12:30 am and 09:00 pm). Change in BW was measured at the beginning of each experimental phase and the diet adjusted accordingly, and individual feed intake was recorded daily. Concentrate samples were collected at the beginning of each confinement period and individual hay samples were obtained for each confinement day 38 hours before fecal collection. No influence of LY was observed on BW change (P = .64), feed intake (P = .48), hay intake (P = .48), or concentrate intake (P = .47). S cerevisiae supplementation improved apparent digestibility of dry matter (64.5% vs. 60.1%, P = .03), organic matter (66.1% vs. 61.6%, P = .04), neutral detergent fiber (42.5% vs. 35.9%, P = .04), and acid detergent fiber (36.5% vs. 28.0%, P = .03) with a positive trend on crude protein (P = .08). In the present study, the administration of LY to horses significantly improved the digestion of the fiber fractions of the diet.

Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants

The effects of yeast supplementation on intake, production, and rumen fermentation characteristics have been widely studied, but results are inconsistent between different studies. A quantitative meta-analysis was applied to 110 papers, 157 experiments, and 376 treatments dealing with yeast supplementation in ruminants. The objective was first to highlight the major quantitative effects of live yeast supplementation on intake, rumen fermentation, and milk production, and second, to identify major differences in experimental conditions between studies that can affect the response to treatment. Some of these experimental conditions are referred to as interfering factors. Yeast supplementation increased rumen pH (+0.03 on average) and rumen volatile fatty acid concentration (+2.17mM on average), tended to decrease rumen lactic acid concentration (−0.9mM on average), and had no influence on acetate-to-propionate ratio. Total-tract organic matter digestibility was also increased by yeast supplementation (+0.8% on average). Yeast supplementation increased dry matter intake (DMI;+0.44g/kg of body weight; BW), milk yield (+1.2g/kg of BW), and tended to increase milk fat content (+0.05%), but had no influence on milk protein content. Dose effects of yeast supplementation, expressed as log10 [1+(cfu per 100kg of BW)], globally confirmed the qualitative effects observed in the first analysis. The positive effect of yeast supplementation on rumen pH increased with the percentage of concentrate in the diet and with the DMI level. It was negatively correlated with the level of dietary neutral detergent fiber (NDF). The positive effect of yeast supplementation on rumen volatile fatty acid concentration increased with DMI and crude protein levels. The positive effect of yeast supplementation on organic matter digestibility increased with the percentage of concentrate and NDF in the diet. The negative effect of yeast supplementation on lactic acid concentration tended to decrease when the DMI level and the percentage of concentrate in the diet increased. The effects of interfering factors were globally similar when either dose effect or qualitative effect of yeast was taken into account. Although rumen fermentation efficiency per se was not measured, these results suggest an improvement in rumen fermentation by yeast supplementation. This effect could, however, be modulated by several different factors such as DMI, percentage of concentrate or NDF in the diet, or species.

The effects of live yeast supplementation to dairy cows during the hot season on production, feed efficiency, and digestibility

The current study examined the effects of live yeast (LY) supplementation to dairy cows during the summer season on milk production, feed efficiency and ration digestibility. Forty-two dairy cows (14 primiparous and 28 multiparous) were fed either a control lactating diet or supplemented with 1g of LY (Saccharomyces cerevisiae, Biosaf, Lesaffre) per 4kg of dry matter consumed. The LY amounts were adjusted twice a week. Four rumen samples were taken from 30 cows in 2-h periods and ammonia concentrations were determined. Fecal grab samples from 30 cows were collected during 3 consecutive days, to determine the apparent digestibility of diets. The daily dry matter intake in the LY group was 2.5% greater compared with the control group (24.7 and 24.1kg, respectively). The daily average milk yield of the LY group was greater by 1.5kg (4.1%) compared with the control group (37.8 vs. 36.3kg, respectively). There were no significant differences in the milk fat and protein percentages, but fat yield was greater in the LY group than in the control. The fat-corrected milk 4% was 2.0kg (6.1%) greater in the LY group than in the control group (34.8 vs. 32.8kg, respectively). The efficiency of using dry matter to produce 4% fat-corrected milk was 3.7% greater in the LY group compared with the control group. The ruminal ammonia concentrations after feeding were greater in the control group than in the LY group (151.9 vs. 126.1 mg/l, respectively). No differences were observed among groups in the total tract apparent digestibility of dry matter and other diet components. The pH values in the rumen that were determined in a companion trial using 4 fistulated cows tended to be higher in cows that were supplemented with LY than in the control (6.67 vs. 6.54, respectively). It may be concluded that LY supplementation to dairy cows during the hot season improved the rumen environment in a way that increased the dry matter intake and in consequence enhanced the productivity and efficiency.

Effects of live yeast on the performance, nutrient digestibility, gastrointestinal microbiota and concentration of volatile fatty acids in weanling pigs

Two experiments were conducted to evaluate the effects of live yeast supplementation on performance, nutrient digestibility, enteric microbial populations and volatile fatty acid (VFA) concentration of weanling pigs, receiving diets supplemented with aureomycin and elevated doses of CuSO4. In experiment 1, 90 crossbred pigs (7.20 ± 0.44 kg, 28 d of age) were randomly allotted to one of five dietary treatments containing either 0, 4.0 · 106, 9.0 · 106, 2.6 · 107, or 5.1 · 107 cfu Saccharomyces cerevisiae per gram with six replicate pens per treatment and three pigs per pen. BWG and feed intake increased quadratically during days 1 – 14 and days 1 – 28 as live yeast levels increased (p < 0.01). Pigs fed the diet containing 2.6 · 107 cfu yeast per gram had the highest BWG and feed intake among the treatments. In experiment 2, 48 crossbred pigs (7.64 ± 0.72 kg, 28 d of age) were fed diets containing live yeast at 0 or 3.2 · 107 cfu of S. cerevisiae per g with six replicate pens per treatment and four pigs per pen. The yeast supplementation improved BWG and feed intake during days 1 – 14 (p < 0.01) and days 1 – 28 (p < 0.05). Treatment differences were not observed in any of the bacterial populations, yeast numbers or VFA concentrations, at any of the sites of the gastrointestinal tract tested. Total tract nutrient digestibility was also not different between treatments. Overall, dietary supplementation of live yeast had a positive effect on BWG and feed intake of weanling pigs, receiving diets supplemented with aureomycin and elevated doses of CuSO4. The improvement in BWG appears to be partly related to an increase in feed intake. The mechanism of yeast improving feed intake of piglets needs to be explored.

Growth performance, nutrient digestibility, and fecal microflora in weanling pigs fed live yeast1

Two experiments were conducted to evaluate the effects of live yeast supplementation on nursery pig performance, nutrient digestibility, and fecal microflora and to determine whether live yeast could replace antibiotics and growth-promoting concentrations of Zn and Cu in nursery pigs. In Exp. 1, 156 pigs were weaned at 17 d of age (BW = 5.9 kg) and allotted to a 2 x 2 factorial randomized complete block design (six or seven pigs per pen with six pens per treatment). Factors consisted of 1) dietary supplementation with oat products (oat flour and steam-rolled oats; 0 or 27.7%) and 2) yeast supplementation at 0 or 1.6 x 10(7) cfu of Saccharomyces cerevisiae SC47/g of feed. In Exp. 2, 96 pigs were weaned at 17 d of age and allotted to a 2 x 2 factorial randomized complete block design (four pigs per pen with six pens per treatment) with factors of 1) diet type (positive control containing growth-promoting concentrations of Zn, Cu, and antibiotics or negative control) and 2) live yeast supplementation (0 or 2.4 x 10(7) cfu of Saccharomyces cerevisiae SC47/g of feed). The inclusion of oat products in Exp. 1 decreased (P < 0.10) overall ADG and final BW. Yeast supplementation did not affect growth performance of pigs in Exp. 1 (P = 0.65); however, ADG in Exp. 2 was 10.6% greater (P < 0.01) and ADFI was increased by 9.4% (P < 0.10) in pigs supplemented with yeast in the positive control diet. Addition of Zn, Cu, and antibiotics to the diet improved gain:feed ratio during the prestarter period (P < 0.02) and overall (P = 0.10). In Exp. 1, inclusion of oat products increased (P < 0.01) total bacteria in feces when measured on d 10. Fecal lactobacilli measured on d 28 were reduced (P < 0.05) in pigs fed diets with oat products and yeast (interaction, P < 0.05). In Exp. 2, yeast supplementation decreased (P < 0.05) total bacteria and lactobacilli. Dietary yeast resulted in a greater (P < 0.05) yeast count in feces of pigs during the starter phase of Exp. 1. Yeast decreased (P < 0.10) the digestibility of DM, fat, and GE in the prestarter phase and DM, fat, P, and GE in the starter phase, whereas oat products increased the digestibility of DM, CP, fat, and GE (P < 0.05) in the prestarter phase. Results indicate that live yeast supplementation had a positive effect on nursery pig performance when diets contained growth-promoting antimicrobials. Nonetheless, the response was variable, and the conditions under which a response might be expected need to be further defined.