Isolation and characterization of yeasts from fermented apple bagasse as additives for ruminant feeding

Abstract 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.

Respostas reprodutivas e metabólicas de ovelhas alimentadas com bagaço de caju desidratado, durante o pós-parto / Reproductive and metabolic responses of ewes fed dehydrated cashew apple bagasse during the postpartum period

Avaliou-se o efeito da adição de bagaço de caju desidratado (BCD), durante o pós-parto, em 41 ovelhas, alojadas com suas crias em baias, onde recebiam, à vontade, 75 por cento de capim-elefante + 25 por cento de concentrado (DI; n=17), ou 50 por cento de BCD + 25 por cento de capim-elefante + 25 por cento de concentrado (DII; n=24). Cinquenta dias pós-parto, o estro foi sincronizado, e as ovelhas submetidas à monta natural. O grupo DI perdeu mais peso (P<0,05), e o consumo de proteína bruta e de fibra em detergente neutro foi maior nesse grupo (P<0,001). A inclusão de BCD na dieta II induziu ao aumento do consumo de matéria seca, extrato etéreo e fibra em detergente ácido (P<0,001) e redução significativa das concentrações de colesterol, lipídios totais, albumina e proteína total (P<0,001). Não houve diferença entre os grupos (P>0,05) no tempo de retorno do primeiro corpo lúteo funcional, na resposta à sincronização do estro e nas taxas de gestação e prolificidade. A inclusão de 50 por cento de BCD amenizou as perdas de peso, foi bem consumida e não influenciou nas respostas reprodutivas após a sincronização do estro.

The effect of the addition of dehydrated cashew apple bagasse (DCB) to the diet on ewe postpartum response was evaluated on 41 ewes, housed with their kids in pens, where they received two diets containing 75 percent of Elephant Grass plus 25 percent of concentrate (Diet I; n=17), or 50 percent of DCB plus 25 percent of Elephant Grass plus 25 percent of concentrate (Diet II; n=24). On the 50th day postpartum, estrus was synchronized and ewes mated. Diet Igroup exhibited a greater loss of live weight (P<0.05) and higher intakes of crude protein and neutral detergent fiber (P<0.001). By contrast, animals from diet II showed a significantly increase in dry matter, ether extract, and acid detergent fiber intakes (P<0.001), and lower plasmatic concentrations of cholesterol, total lipids, albumin, and total protein (P<0.001). No differences were found between groups (P>0.05) for the presence of first functionally CL, estrus synchronization response, and gestation or prolificity rates. Thus, the addition of DCB to the diet was well accepted, induced a reduction of weight loss, and did not affect the reproductive response of ewes.