Effect of Yeast Culture Supplementation on Digestibility of Varying Forage Quality in Mature Horses

Supplementation of yeast culture to equine diets has improved digestion of nutrients in some studies but not others. Improving the digestibility of lower-quality forages could be advantageous both for the producer and for the horse's health. The objective of this study was to evaluate the effect of yeast culture on digestibility of high- and low-quality forage in mature horses. Sixteen geldings (483.6 ± 25.5 kg and 6.8 ± 3.2 years), of Quarter Horse (n = 14) and Thoroughbred (n = 2) breeding, were used in a 4 × 4 Latin square design with 28-day treatment periods. Russell Bermuda grass hay of either high (13.1% crude protein (CP), 73.1% neutral detergent fiber (NDF), 35.3% acid detergent fiber (ADF), and 6.0% ash) or low (8.1% CP, 75.3% NDF, 37.6% ADF, and 4.3% ash) quality was offered at 1.35% of body weight (BW, dry matter [DM] basis). Diets consisted of high-quality forage with the addition of yeast culture (HY), high-quality forage without yeast culture (HC), low-quality forage with the addition of yeast culture (LY), and low-quality forage without yeast culture (LC). All horses were fed a commercial grain mix (12.6% CP, 25.4% NDF, 12.1% ADF, and 4.0% ash) offered at 0.45% of BW (DM basis) daily. Yeast culture was added to the grain mix during the morning feeding at a rate of 56 g per horse. Body weight was measured weekly and feed intake was adjusted accordingly. Fecal samples were obtained every 6 hours on the last 3 days of each treatment period. Horses receiving low-quality hay (LY and LC) had greater (P < .01) intake expressed as a percentage of BW compared with horses receiving high-quality hay (HY and HC). No influence of yeast culture supplementation was seen on intake of grain or forage (P < .23 and P < .62, respectively). Digestibility of DM, organic matter (OM), CP, and NDF were greater (P < .01, P < .01, P < .01, and P < .01, respectively) for the diets with high-quality forage compared with the diets with low-quality forage. Dry matter, CP, and NDF digestibilities were greater (P < .09, P < .03, and P < .05, respectively) for horses receiving LY compared with LC. Supplementation of yeast culture to mature horses improved digestibility of lower-quality Bermuda grass hay.     

猪生长阶段与饲粮类型对酸不溶灰分法测定养分消化率的影响

本试验旨在探讨猪饲粮中添加硅藻土来源的盐酸不溶灰分(AIA)后,以饲粮和粪中AIA含量测定养分消化率的可行性。试验采用2×2两因素完全随机设计,其中饲粮设2个处理,即玉米-豆粕型饲粮和玉米-玉米干酒糟及其可溶物(cDDGS)-米糠粕型饲粮;猪生长阶段设2个处理,即生长期(60~100日龄)和育肥期(100~140日龄)。每个生长阶段分为2个试验期,每期试验包括5 d预试期、5 d全收粪期和3 d部分粪样定点采集期,测定饲粮及粪样的干物质、AIA、总能和粗蛋白质含量,从而计算饲粮的养分消化率及AIA的回收率。结果表明:1)玉米-豆粕型饲粮和玉米-cDDGS-米糠粕型饲粮中AIA的平均回收率分别为97.29%和97.54%,差异不显著(P0.05);2)全收粪法和AIA法测定的养分消化率差异不显著(P0.05),猪生长阶段和饲粮类型对其测定的养分消化率的绝对差影响不显著(P0.05);3)部分粪样定点采集AIA法测定的干物质消化率与全收粪AIA法差异不显著(P0.05),猪生长阶段和饲粮类型对其测定的干物质消化率的绝对差影响不显著(P0.05)。综合以上研究结果,在2种猪饲粮中添加0.8%的硅藻土后,以AIA法测定饲粮养分消化率不受猪生长阶段及饲粮类型的影响,且AIA法与全收粪法的测值是可比的。     

Effect of Live Yeast Culture Supplementation on Fibrolytic and Saccharolytic Bacterial Populations in the Feces of Horses Fed a High-Fiber or High-Starch Diet

The objective of this study was to assess the effect of live yeast (Saccharomyces cerevisiae) supplementation on the populations of specific cellulolytic (Fibrobacter succinogenes and Ruminococcus flavefaciens) and saccharolytic (Streptococcus equinus and Streptococcus bovis) bacteria in the feces of horses fed high-starch and high-fiber diets. Four horses were each fed diets consisting of high fiber with no yeast (HF), high fiber with yeast (HFY), high starch with no yeast (HS), and high starch with yeast (HSY) in a 4 × 4 Latin-square design study. Fresh fecal samples were collected on the last 3 days of each 31-day experimental period and were then assessed, using semiquantitative real-time PCR, for total bacterial load and levels of target bacterial species, relative to the total bacterial load. The most abundant of the target species was F. succinogenes, and the HSY diet resulted in a significant (P = .045) reduction in relative levels of this bacterium. No significant effect (P = .224) of diet was observed in relation to abundance of R. flavefaciens. Results show that diet did not have a significant (P = .068) effect on relative quantities of S. equinus, although there appeared to be a trend for increased levels of this bacterium during feeding of high-starch diets. Numbers of S. bovis were higher (P < .001) when horses were fed HS and HSY diets than when fed the HF and HFY diets. Significant variation in levels of S. equinus (P = .024) and S. bovis (P = .049) was observed between individual horses.     

Influence of Feeding Horses a High Fiber Diet With or Without Live Yeast Cultures Supplementation on Feed Intake,Nutrient Digestion,Blood Chemistry,Fecal Coliform Count,and In Vitro Fecal Fermentation

Sixteen Quarter Horse mares (body weight: 450–500 kg) were used in a complete randomized design to determine the effects of feeding horses a high fiber diet with or without yeast cultures addition on nutrient intake and digestion, blood chemistry, fecal coliform count, and in vitro fecal fermentation. The treatments were (1) a basal diet without yeast cultures addition (control treatment), (2) control diet plus Procreatin 7 at 15 g/mare/d (P7 treatment), (3) control diet plus Biocell F53 at 11 g/mare/d (F53 treatment), or (4) control diet plus Biosaf SC47 at 15 g/mare/d (SC47 treatment). The basal concentrate diet consisted of a mixture of 50% commercial concentrates and 50% wheat bran fed at 4 kg/mare and offered twice daily at 04:00 and 16:00 hours, while oat straw was offered ad libitum at 05:00 and 17:00 hours. The mares fed the F53 had higher (P < .05) oat straw and total nutrient intakes compared to the control diet. Addition of Biocell F53 and Biosaf SC47 yeast cultures increased (P < .05) all nutrients' digestibilities. Feeding the yeast cultures resulted in higher crude protein (P = .029), neutral detergent fiber (P = .042), and acid detergent fiber (P = .035) digestibilities compared to the control diet. The SC47 treatment had lower blood total protein (P = .014) than the control treatment. Higher (P < .05) asymptotic in vitro fecal gas production was obtained with F53 treatment compared to SC47 treatment without differences between F53, P7, and control treatments. Increased methane production was obtained (P < .05) with F53 and SC47 treatments compared to the control treatment. It can be concluded that daily addition of Biocell F53 yeast culture at 11 g/mare/d resulted in higher feed intake and nutrients digestibility without affecting the mare's health.     

十二指肠灌注蛋氨酸对肉牛小肠氨基酸消化率的研究

根据基础日粮+待测氨基酸法,由十二指肠瘘管连续灌注DL Met,通过小肠氨基酸消化率确定基础日粮条件下十二指肠蛋氨酸最佳灌注量。试验采用4×4拉丁方设计,试牛饲喂相同的基础日粮,DL 蛋氨酸的浓度为0(Ⅰ组)、9(Ⅱ组)、13(Ⅲ组)和17(Ⅳ组)g/d,预试期12d,正试期7d,采用Cr2O3标记物法测定食糜流通量。结果表明:十二指肠灌注13g蛋氨酸(Ⅲ组)显著增加十二指肠Met、Cys、Pro、Lys以及TAA和EAA流通量(P<0 05),降低回肠Asp、Thr、Glu、Gly、Val、Ile、Phe、Lys和His的流通量,但差异不显著(P>0 05),显著提高Asp、Thr、Ser、Glu、Phe、His、Arg在小肠的表观消化率(P<0 05),证明本试验条件下十二指肠蛋氨酸最佳灌注量为13g/d。     

酵母培养物对犊牛消化率和体尺指标影响的研究

本试验研究了犊牛日粮中添加酵母培养物对日粮营养成分消化率和体尺指标的影响,并对犊牛新型饲喂模式进行了有意义的探索。本试验结果表明,在日粮中添加酵母培养物和饲喂颗粒精料日粮,可以提高试验犊牛的消化率,促进其生长发育,缩短青年牛的培育周期,降低饲养成本,获得显著的经济效益。     

瘤胃投饲不同形式蛋氨酸对肉牛小肠氨基酸流量和消化率的影响

选择安装瘤胃、十二指肠前端和回肠末端瘘管的健康肉牛4头,采用4×4拉丁方设计,研究瘤胃投饲不同形式蛋氨酸对肉牛小肠氨基酸消化率的影响。投饲蛋氨酸添加剂分别为0(Ⅰ组)、DL-Met(Ⅱ组)、动物油包被Met(Ⅲ组)和吸附MHA(Ⅳ组)。结果表明:试牛总氨基酸在小肠的表观消化率平均为69.88%±0.83%,其中必需氨基酸(EAA)为74.61%±1.23%,非必需氨基酸(NEAA)为64.25%±0.51%。Lys和His在小肠的表观消化率最高,分别为80.14%±1.11%和80.15%±1.23%,Gly和Pro在小肠的表观消化率最低,分别为53.52%±0.30%和55.53%±2.03%。Ⅲ组ThrI、le、Tyr、Phe、Pro、Cys在小肠的表观消化率显著高于Ⅰ组(P<0.05),而Ala则相反。Ⅳ组ThrI、le、Phe、Cys在小肠的表观消化率显著高于Ⅰ组(P<0.05)。与Ⅰ组相比,Ⅱ组只显著增加了Phe在小肠的表观消化率(P<0.05)。     

Effects of Live Yeast (Saccharomyces cerevisiae Strain 1026) Supplementation on the Closure of Articular Growth Plates in Quarter Horse Foals

To avoid osteoarticular injury and to minimize farm losses in animal use and sales, breaking in young horses is ideally done as soon as growth plates have closed. An experiment was performed to determine whether dietary live yeast could shorten the time for growth plate closure. Twenty-four female Quarter Horse foals, 8 months of age, were allotted to two treatment groups (12 animals each) in a completely randomized experimental design. Horses were fed 0 or 20 g live yeast daily from 8 to 24 months of age. Diets were regular for a stud farm in the area of the study in Argentina. Foals at 8 months of age had a low baseline calcium urinary fractional excretion compatible with a primary calcium-deficient diet for this age in Argentina. Growth plate closure was evaluated by dorsum–palmar radiographs at baseline. A second evaluation was performed when foals were 12 months of age and a third evaluation when foals were 24 months of age. Blood and urine were sampled simultaneously at the same intervals to evaluate bone and mineral metabolism parameters (serum phosphorus, calcium, magnesium; alkaline phosphatase; and hydroxyproline). Calcium, magnesium, and phosphorus urinary fractional excretions were also calculated. Closure scales of distal radius growth plate data were compared using Wilcoxon test and bone markers were compared using Student t-test. Baseline radiological evaluation of growth plates showed that in 84% of foals, the distal metacarpi were either half closed or fully closed at 8 months; therefore, subsequent evaluations were limited to the distal radius. After 4 months of supplementation with live yeast at 12 months of age, a positive but nonsignificant elevation in calcium urinary fractional excretion was observed. At 24 months of age, radiographs showed a nonsignificant but positive effect in the live yeast group, with more than 50% of foals having closed distal radius growth plates. Although bone markers at 24 months of age did not differ (P > .05) between groups, some individual horses showed a positive effect with yeast supplementation.