RESUMO
We investigated whether the feed intake efficiency, digestibility, microbial efficiency, and nitrogen balance would be affected by inclusion of rehydrated corn grain silage with crude glycerin or water to substitute the dry corn in diets for feedlot lambs. Ten crossbred (Santa Ines × Dorper) uncastrated male lambs (25.6 ± 4.0 kg body weight) were assigned in a replicated 5 × 5 Latin square design and subjected to five experimental diets, one containing dry corn and four diets containing corn grain silage rehydrated with crude glycerin in levels of 0, 75, 150, and 225 in g/kg of natural matter. The moisture of 32.5% was maintained in all silages. The inclusion of crude glycerin represented 0, 40, 80, and 120 g/kg of total diet. The inclusion of rehydrated corn silage did not affect the DM, CP, EE, and ED intake. The diets with rehydrated corn silage improved the digestibility of DM, without affecting the fiber digestibility. The nitrogen losses were insignificant, resulting in the efficient use of dietary nutrients. In conclusion, corn silage rehydrated with 150 g/kg NM of crude glycerin is recommended as a feed to substitute dry corn diet, as it did not influence the nutrients intake, increased the dry matter digestibility with efficient use of the dietary nutrients, improving the animal performance in the feedlot.
Assuntos
Glicerol , Silagem , Zea mays , Animais , Dieta/veterinária , Fibras na Dieta , Digestão , Lactação , Masculino , Leite , Rúmen , Ovinos , Silagem/análiseRESUMO
Our objective was to determine the effects of maturity and storage length on the fermentation pattern, ruminal disappearance of nutrients, and recovery of digestible nutrients in flint corn (Zea mays L.) silage harvested with a pull-type machine without a kernel processor. Corn plants were harvested at 300 g kg−1 DM (low dry matter, LDM) or 400 g kg−1 DM (high dry matter, HDM) and stored for 0, 7, 14, 30, 60, 90, 120, and 180 d in laboratory silos. Corn harvested at HDM had a higher proportion of long particles (>19 mm), more intact kernels, and lower kernel processing score. There was an interaction between maturity and storage length for several fermentation end-products, DM recovery, ruminal disappearance of nutrients, and recovery of digestible DM. Overall, the concentrations of fermentation endproducts were higher in LDM than in HDM silage. The DM recovery decreased over time, mainly for LDM silage. Ruminal disappearance of nutrients (starch, CP, and DM) increased with storage length, with greater values for LDM silage at shorter storage, but closer values among LDM and HDM at longer storage periods. The recovery of digestible DM (DM recovery × ruminal disappearance) slightly increased in LDM silage up to 26 d of fermentation, but it markedly increased in HDM silage, mainly up to 60 d of storage. Storing for longer periods is a strategy to partially offset the negative impact of maturity on the digestibility of flint corn silage harvested with pull-type machines without kernel processor.(AU)
Assuntos
Zea mays/química , Fermentação/fisiologia , Proteólise , SilagemRESUMO
The objective of this study was to evaluate the effects of dietary supplementation with live yeast (Saccharomyces cerevisiae), mannan-oligosaccharides and the combination of these additives on the inflammatory response, ruminal parameters and rumen morphology of sheep fed a high grain-based diet. Thirty-Two Dorper x Santa Ines crossbred lambs with an average weight of 24±2 kg were distributed in a completely randomized design. The animals were housed in individual stalls and fed ad libitum. Diet treatments were: Control (without additive); LY (2 g/kg DM of live yeast, Saccharomyces cerevisiae), MOS (2 g/kg DM of mannan-oligosaccharides) and LY+MOS (2 g/kg DM of LY + 2 g/kg DM of MOS). The experiment lasted 42 days. The supplementation with MOS alone and the additives combination resulted in increased ruminal pH (P<0.01), while the total concentrations of short chain fatty acids (SCFA) in the rumen were higher (P<0.05) only in the diets with LY and MOS. Ammonia (NH3) concentration in the rumen decreased (P<0.04) with the additives usage. Diets with LY, MOS and with additives combination reduced (P<0.01) the levels of lipopolysaccharides (LPS) in the plasma with values of 0.46; 0.44 and 0.04 EU/mL, respectively when compared to the control (0.93 EU/mL). MOS and LY+MOS treatments had reduced stratum corneum thickness (P<0.01) in comparison to the control treatment. The total thickness of ruminal epithelium was lower with the addition of MOS in the diet (P<0.03) than with LY additive. The incidence and severity of hepatic abscesses in animals whose diet was supplemented with LY and LY+MOS was lower (P<0.05) than in animals fed the control diet. The use of LY, MOS and LY+MOS in the high-concentrate diets for sheep reduced NH3 concentrations and LPS translocation into the bloodstream. Diets containing MOS and LY+MOS enhanced the health of the ruminal epithelium by reducing the thickness of the stratum corneum, and diets containing LY and LY+MOS decreased the incidence and severity of hepatic abscesses.