Leveduras vivas em dietas de alta forragem para novilhas
Year: 2015
Type: dissertation
Abstract: Low quality forage result in lower fermentation rates and negatively \naffect ruminant productivity. This justifies the use of feeding strategies capable \nof improving the exploitation of this type of forage by the animals. Live yeast \ncan improve the efficiency of resources applied to animal feed. We evaluated the \neffect of yeast over performance and digestibility of dairy heifers fed with low \nquality and high diet inclusion, tropical or temperate forage. The heifers were \nindividually fed in tie stall. We fed 36 hybrid heifers (initial weight of 144 ± 70 \nkg) a standardizing diet for 12 days and, subsequently, were treated for 126 days \nwith co-variable adjustment in randomized blocks design. The treatments were \narranged in 2x2 factorial scheme with two types of hay (Tifton or oat) and yeast \n(Saccharomyces cerevisiae) or control. A mixture of soy, mineral premix and 10 \ng of yeast (2x1010 c.f.u. of live cells) was offered daily and before the hay to \nguarantee total intake. Diet proportion (%DM) was of 91.5% of forage and 7.4% \nof soybean meal. The supplementation with yeast increased dry matter intake of \nthe diet with Tifton hay (5.0 vs. 4.6 kg, P=0.05). The oat hay treatment provided \nhigher gain than the treatment with Tifton hay (0.44 vs 0.29 kg) and higher \nefficiency (0.10 vs 0.07, P<0.01). The yeast induced height gain in the treatment \nwith Tifton hay (117 vs 121, P<0.02). The digestibility of DM, OM and NDF \n(P<0.01). The supplementation with yeast tended to reduce the time of the first \nmeal (P=0.11). Intake rate (kg/min) was higher in the treatment with Tifton hay \n(91 vs 80). Yeast stimulated the synthesis of microbial protein for Tifton hay \n(1.23 vs 1.00, P<0.01). The pH ruminal ammonia presented higher values with \nTifton hay (average of 6.1 and 6.5, respectively). Yeast changed the digestive \npattern when using oat hay, presenting higher intake in the afternoon (P<0.01) \nand lower in the morning (P<0.05). The treatments with Tifton induced higher \nrejection of fine particles (P=0.01). The diets with high forage and low quality, \nthe supplementation with yeast did not improve digestibility of neutral detergent \nfiber. However, yeast presented a negative effect over intake, weight gain and \nfeed efficiency of heifers fed oat hay and positive effects over intake of dry \nmatter and the synthesis of microbial protein of heifers fed Tifton hay.
Author: Amanda Vasconcelos Guimarães
Language: Portuguese
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W1831531808