Solid-state fermentation can be used to produce feeds for ruminants, which can provide an enriched population of yeasts to improve ruminal fermentation. Fermentation of apple bagasse was performed to obtain a yeast-rich product, with the objective of isolating, identifying, and characterizing yeast strains and testing their capability to enhance in vitro ruminal fermentation of fibrous feeds. Yeasts were isolated from apple bagasse fermented under in vitro conditions, using rumen liquor obtained from cannulated cows and alfalfa as a fibrous substrate. A total of 16 new yeast strains were isolated and identified by biochemical and molecular methods. The strains were designated Levazot, followed by the isolate number. Their fermentative capacity was assessed using an in vitro gas production method. Strain Levazot 15 (Candida norvegensis) showed the greatest increase in gas production (p < 0.05) compared with the yeast-free control and positively affected in vitro ruminal fermentation parameters of alfalfa and oat straw. Based on these results, it was concluded that the Levazot 15 yeast strain could be potentially used as an additive for ruminants consuming high-fiber diets. However, further studies of effects of these additives on rumen digestion, metabolism, and productive performance of ruminants are required.

Two experiments were conducted to compare a supplemental blend of essential oils alone (EO) or combined with enzymes (EO + ENZ) versus virginiamycin (VM), on characteristics of growth performance (Exp. 1) and digestion (Exp. 2) in finishing lambs. Lambs were fed a high-energy finishing diet supplemented with: (1) no supplement (control); (2) 150 mg supplemental EO; (3) 150 mg supplemental EO plus 560 mg alpha-amylase (EO + ENZ); and 4) 25 mg VM. Compared with the control, growth performance response to EO and VM were similar, enhancing (5.7%, p < 0.05) feed efficiency and observed dietary net energy. Compared with control, supplementation with EO + ENZ tended (p = 0.09) to increase dry matter intake (6.8%), improving (p < 0.05) weight gain and feed efficiency (10.4 and 4.4%, respectively). Dietary energy utilization was greater (2.7%, p < 0.05) for EO and VM than EO + ENZ. Treatment effects on the carcass and visceral mass were small, but additive supplementation decreased (p ≤ 0.03) the relative weight of the intestines. There were no treatment effects on measures of digestion nor digestible energy of the diet. Supplemental EO may be an effective alternative to VM in high-energy finishing diets for feedlot lambs. Combination EO + ENZ may further enhance dry matter intake, promoting increased weight gain.

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The aim of this trial was to test the effects of the use of eubiotics (pro- and prebiotics) alone or in combination in the diet of lambs finished under subtropical climate conditions. For this purpose, 40 Pelibuey × Katahdin lambs (29.5 ± 4.8 kg initial live weight) were used in a 93 day growth-performance experiment. Dietary treatments consisted of a cracked corn-based finishing diet supplemented with (1) no eubiotics (control), (2) 3 g of probiotics (live Saccharomyces cerevisiae, SC), (3) 3 g of prebiotics (mannan oligosaccharide plus b-glucans, MOS), and (4) a combination of 1.5 g of SC and 1.5 g of MOS (SC+MOS). Throughout the study, the average temperature humidity index (THI) was 78.60. Compared to controls, supplementation with SC or MOS, alone did not affect average daily gain (ADG), but enhanced feed efficiency by 5.6% and 6.9% (gain-to-feed ratio, G:F) and dietary net energy by 4.6% and 5.9%, respectively. Compared to controls, SC+MOS enhanced ADG (10%), G:F (9.5%), and dietary net energy (7.2%). Lambs fed SC+MOS had also greater ADG, G:F, and dietary net energy compared to lambs fed SC alone. When compared to MOS, the combination enhanced ADG (10.4%, p = 0.04). This effect could be attributed to the increased dry matter intake (7.6%, p = 0.06), as neither G:F nor dietary energy was significantly affected. Compared with controls and SC, supplementation with MOS alone and SC+MOS increased kidney–pelvic–heart fat, while SC supplementation tended (p = 0.08) to reduce 4.1% the relative intestinal mass (as a proportion of empty body weight) when compared to controls. Treatment effects on the other carcass measures were not significant. In the present study, supplemental probiotics and/or prebiotics improved dietary energetic efficiency in lambs finished under subtropical climatic conditions. The combination of probiotics with prebiotics reinforced this positive effect.

This study assessed the effect of inclusion of a yeast probiotic on the counts of lactobacilli, total aerobes (TA), total coliforms (TC), E. coli and Salmonella in the composting of laying hen manure. The yeast probiotic concentration (0, 7.5 and 15% wet basis) in the composting effect was defined as factor A and the fermentation time (FT) (0, 7 and 23 days) was defined as factor B. A completely randomised design with a factorial arrangement of 3 Â 3 and four replicates was used. An interaction was found in Salmonella and pH (p < .0001). The lowest (p < .05) Salmonella counts were obtained at day 7 in the treatments with 7.5% and 15%, respect to the control. The lowest values (p < .05) for pH were obtained at day 23 in the treatments containing 0 and 15%. Lactobacilli, E. coli, TC, whereas TA counts were affected only by fermentation time (p < .05). In all treatments, lactobacilli increased (p < .05) by day 7. E. coli and TC counts decreased (p < .05) across the fermentation time and TA remained constant for the first seven days. (p < .05). Anaerobic fermentation of poultry litter over 23 days is sufficient to lower the pH and eliminate pathogenic microorganisms. ARTICLE HISTORY

To examine the growth of Candida norvegensis (strain Levazoot 15), four experiments were conducted with different sources of energy, nitrogen, vitamins, and microminerals. Optical density was used as an indirect measure of strain growth in a fully randomized factorial design, in which principal factor A was the source of energy, nitrogen, vitamins, or microminerals and principal factor B was the measurement time point (0, 20, or 40 h). The results showed that the yeast strain used glucose (primarily sucrose and lactose) as the energy source and tryptone as the nitrogen source. The addition of B-complex vitamins or microminerals was not necessary for strain growth. It is concluded that the strain Levazoot 15 preferentially utilizes glucose as a source of energy, tryptone as a source of nitrogen and manganese as a mineral source, and that no vitamin source was necessary for growth.

Borregos de pelo. Zeolita. Eficiencia energética. Dieta de finalización. resUMenEl objetivo de este estudio fue evaluar el efecto de la adición de diferentes niveles (0, 1,5, 3 y 4,5%) de zeolita en dietas integrales de finalización sobre la respuesta productiva y la eficiencia en la utilización de la energía neta de la dieta de ovinos de pelo. Para lo anterior, 40 ovinos machos ¾Katahdin × ¼Pelibuey (peso inicial = 32,28±2,34 kg) se asignaron a 20 corraletas (2 ovinos/corraleta, 5 corrales/tratamiento) alimentándose durante 75 días con alguno de los 4 tratamientos. Las dietas ofrecidas fueron tipo integral. La dieta testigo (sin zeolita) contenía 16,51% de proteína cruda (PC) y 1,39 McalENg/kg y la cantidad total de zeolita incluida en cada tratamiento sustituyó al maíz y a la pasta de soja en partes iguales. Por cada nivel de sustitución del maíz-pasta de soja se disminuyó la concentración de PC en 0,11 puntos porcentuales y la energía neta en 0,03 Mcal/kg. El sustituir maíz y pasta de soja por zeolita hasta un nivel de 1,5% en la dieta no afectó el consumo de materia seca (MS), la ganancia diaria, la eficiencia alimenticia, la utilización de la energía neta de la dieta (EN observada sobre la EN esperada) o la retención aparente de energía por unidad de MS consumida. El aumentar a el nivel de suplementación de zeolita por encima de 1,5% incrementó la eficiencia alimenticia, la utilización de la energía neta de la dieta y la retención aparente de energía por unidad de MS consumida siendo la respuesta máxima para el nivel de inclusión de 3% (componente cuadrático, p<0,01). Con respecto al grupo testigo, la inclusión de 3% de zeolita a la dieta mejoró (p<0,01) en 6,8% la eficiencia alimenticia, en 8.4% la utilización de la energía neta de la dieta y en 8,9% la retención aparente de energía por unidad de MS consumida. La inclusión de zeolita por encima de 1,5% a dieta de finalización mejora la utilización de la energía neta de la dieta. En base al rendimiento productivo y la eficiencia en la utilización de la energía neta de la dieta, la respuesta óptima observada para los corderos en el presente estudio fue con el 3% de inclusión de zeolita. The aim of this study was to evaluate the effect of different supplemental levels (0, 1.5, 3 and 4.5%) of zeolite in total mixed finishing diets on the productive response and efficiency of using dietary net energy in hairy lambs. For this aim, 40 ¾Katahdin × ¼Pelibuey lambs (initial weight = 32.28 ± 2.34 kg) were assigned to 20 pens (2 lambs/pen, 5 pens/treatment) and were fed for 75 days on one of the four treatments. Control diet (no supplemental zeolite) contained 16.51% CP and 1.39 McalNEg/kg, and the total quantity of zeolite included replaced corn and soybean meal in equal parts. For each level of which corn and soybean meal were substituted, CP concentration decreased 0.11 percentage points and net energy decreased 0.03 McalNEg/kg. The partial replacement of corn and soybean meal by zeolite at a level of 1.5% in the diet did not affect DM intake, daily gain, feed eff...

Twenty-four Pelibuey × Katahdin lambs (36.4 ± 2.9 kg initial weight) were used in a 77 d feeding trial in a randomized complete block design to evaluate the influence of a standardized synbiotic-glyconutrient combination (GLY) on growth performance, dietary energetic, and carcass characteristics of lambs finished during a period of high ambient temperature. Dietary treatments consisted of a high-energy basal diet supplemented (% of diet dry matter basis) with 0% versus 0.4% GLY. Throughout the study, the average temperature humidity index (THI) was 76.23, corresponding to the “alert” range, but daily maximum THI exceeded 80 for 2 to 6 h of each day of the 77 d study. Daily GLY intake averaged 0.10 g GLY·kg−1 live weight. Supplemental GLY increased (P = 0.04) daily water intake, but dry matter intake was not affected. Supplemental GLY increased (P < 0.03) initial 56-d, and overall (77-d) average daily gain, gain efficiency and estimated dietary net energy. Lambs fed GLY had greater (P ≤ 0.05) hot carcass weight and fat thickness, and decreased (P = 0.02) kidney-pelvic-heart fat. Supplemental GLY did not affect (P ≥ 0.16) shoulder tissue composition or relative weight of visceral mass. Synbiotic-glyconutrient combination improved growth performance, dietary energy, and carcass weight in lambs finished in high ambient temperatures. Enhancements in growth performance and dietary energetics were most appreciable during the first 56 d of the 77 d finishing period.