Does sugar cane ensiled with calcium oxide affect intake, digestibility, performance, and microbial efficiency in beef cattle?

• Autor(a) principal: Chizzotti, F. H. M.
• Data de Publicação: 2015
• Outros Autores: Pereira, O. G., Valadares Filho, S. C., Chizzotti, M. L., Rodrigues, R. T. S., Tedeschi, L. O., Silva, T. C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1016/j.anifeedsci.2014.12.014; http://www.locus.ufv.br/handle/123456789/23263
• topic: Additive; Feedlot; Fiber; Lime; Sugar cane silage

Two trials were conducted to evaluate how calcium oxide (CaO) as an additive in sugar cane silage affects animal performance and diet digestibility. Experiment 1 included 35 crossbred steers (Holstein × Nellore) with an average body weight (BW) of 350 ± 18.3 kg, which were distributed across a randomized block design with five treatments and seven replicates. The five treatments consisted of sugar cane ensiled with four different levels of CaO (0, 5, 10, and 15 g/kg; fresh basis) and a standard diet of corn silage. The forage concentrate ratio was 50:50 and was formulated to be isonitrogenous (120 g/kg DM). The dry matter intake (DMI) was measured daily and individually. Indigestible acid detergent fiber (iADF) was used as an internal marker to estimate apparent nutrient digestibility. There was a quadratic positive effect (P=0.013) of the CaO levels on DMI (g DM/kg BW), organic matter (OM; P=0.032), and non-fiber carbohydrates (NFC; P=0.014) intake. The average daily gain (ADG) of steers that were fed corn silage diets was similar (P=0.11) to that of those fed sugar cane silage with 5 g/kg of CaO. There was a positive linear effect of the percentage of CaO on the apparent total digestibility of DM (P=0.012), OM (P=0.001), crude protein (CP; P=0.022) and neutral detergent fiber (aNDF; P=0.015) of the diets. In Experiment 2, four ruminally and abomasally cannulated Nellore steers (184 ± 10.2 kg BW) were used with a 4 × 4 Latin square design to evaluate the effect of CaO levels on apparent total and ruminal digestibility of nutrients, ruminal characteristics, and microbial efficiency. The four treatments were composed of the same sugar cane silage diets used in Experiment 1. The aNDF intake decreased linearly (P=0.032) as the percentage of CaO increased. There was a linear positive effect of the percentage of CaO on the apparent total digestibility of DM (P=0.036), OM (P=0.007), CP (P=0.042), and aNDF (P=0.025). There were no effects of CaO levels on the ruminal pH values (P=0.52), ammonia concentration (P=0.22), or microbial efficiency (P=0.283). Adding CaO to sugar cane silage reduces the silage fiber. However, the addition of more than 5 g/kg CaO to sugar cane at ensiling does not improve silage intake and animal performance. Additionally, the use of 15 g/kg of CaO in sugar cane at ensiling decreases diet intake and growth of beef cattle.