Intake and apparent digestibility of heifers fed diets containing sugar cane treated with calcium oxide [Consumo e digestibilidade aparente em novilhas alimentadas com dietas contendo cana-de-açúcar tratada com óxido de cálcio]
de Carvalho G.G.P.,Federal University of Vicosa |
Garcia R.,Federal University of Vicosa |
Pires A.J.V.,State University of Southwest Bahia |
Silva R.R.,State University of Southwest Bahia |
And 4 more authors.
Revista Brasileira de Zootecnia | Year: 2010
This study was developed to evaluate the intake and apparent digestibility of nutrients in dairy heifers fed diets containing sugar cane treated with calcium oxide (CaO). It was also evaluated the prediction efficiency of dry matter intake and food energy value. Twenty Holstein-zebu crossbred dairy heifers, at 200 kg average initial body weight were used, distributed in a completely randomized design, with four diets and five repetitions. The diets were formulated to be isoprotein and to supply 14% crude protein and they were composed of 71% sugar cane treated with 0; 0.75; 1.5 or 2.25% calcium oxide (in natural matter basis) corrected with 1% of urea and ammonium sulfate (9:1) and 29% of concentrate. Intakes of dry matter (DM), organic matter (OM), ether extract (EE), neutral detergent fiber (NDF), neutral detergent fiber corrected for ash and protein (NDFap), indigestibleneutral detergent fiber (iNDF), total carbohydrates (TC), non-fibrous carbohydrates corrected for ash and protein (NFCap) and total digestible nutrients (TDN) (% BW) were linearly reduced with calcium oxide doses. Digestibilities of OM, NDF, NDFap, total carbohidrates and NFCap and TDN content in the diets were not affected. However, hydrolyses of sugar cane with calcium oxide caused reduction in the digestibility of DM and CP. The equations proposed by National Research Council underestimated intakes of DM and TDN and digestible CP and NFC and overestimated intakes of digestible NDF. Hydrolyses of sugar cane with calcium oxide do not improve intake of nutrients neither digestibility of nutrients in dairy heifers. The equations proposed by National Research Council are not efficient to estimate the DM intake and food energy value in experimental conditions. © 2010 Sociedade Brasileira de Zootecnia.
Sodium monensin and Saccharomyces cerevisiae in cattle diets: ruminal fermentation, nutrient digestibility and microbial synthesis efficiency [Monensina sódica e Saccharomyces cerevisiae em dietas para bovinos: fermentação ruminal, digestibilidade dos nutrientes e eficiência de síntese microbiana]
Fereli F.,Mestranda em Zootecnia UEM |
Branco A.F.,Brazilian National Council for Scientific and Technological Development |
Jobim C.C.,Brazilian National Council for Scientific and Technological Development |
Coneglian S.M.,Doutorando em Zootecnia UEM |
And 2 more authors.
Revista Brasileira de Zootecnia | Year: 2010
The study was conducted to evaluate effects of sodium monensin, Saccharomyces cerevisiae and a mixture of both, in cattle diets, on ruminal pH and ammonia concentration, partial and total nutrient digestibility, and microbial protein synthesis in the rumen. Four Holstein steers weighting 320 kg and cannulated in the rumen were used. A 4 × 4 Latin square experimental design was used and treatments consisted of daily intake of: 200 mg of sodium monensin (100I); 100 mg of sodium monensin + 2.5 g of Saccharomyces cerevisiae (50IP); 200 mg sodium monensin + 5 g Saccharomyces cerevisiae (100IP), and 5 g Saccharomyces cerevisiae (100P) supplied daily through the ruminal canula. The diets containing 100I showed lower intestinal and total DM digestion, higher intestinal digestion of neutral detergent fiber (NDF) and ether extract (EE), higher total digestion of crude protein (CP) and ether extract (EE) and higher apparent ruminal and total CP digestibility. The diets containing 100P showed lower ruminal CP digestion, higher ruminal NDF digestion, higher intestinal digestion of OM, CP, and NFC, higher total digestion of OM and EE, higher apparent ruminal NDF digestibility, higher apparent intestinal digestibility of OM and NFC, and higher apparent total digestibility of OM. Regarding microbial protein synthesis, diets with 100P produced higher omasal flow of bacterial nitrogen and higher apparent and true microbial efficiency. The diets that supplied 5 g/d Saccharomyces cerevisiae increased TDN compared to the other diets. The treatments do not differ for ruminal pH and ammonia concentration. © 2010 Sociedade Brasileira de Zootecnia.