Características físicas, químicas e degradação ruminal de grãos de milho

• Autor(a) principal: Lino, Fabiola Alves
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/4008
• topic: Amido; Textura dos grãos; Zea mays L.; Zeína; Grain texture; Starch; Zea mays L.; Zein; PRODUCAO ANIMAL::MANEJO DE ANIMAIS

The objective was to evaluate the physical chemical characteristics of the corn grains and if these affect the ruminal degradability of grain harvested at half milk line. Six corn hybrids were used: AG 1051, BJ 9450 PRO, AG 4051 PRO, IMPACTO VIP, BM 3061 e SG 3060YG. The randomized block design with five replications was used. The experimental plot consisted of four rows of 5.0 m and spaces between rows of 0.6 m. Cobs of the central rows of each plot were harvested when the grains were at half milk line. Posteriorly were dried in a forced air at 55 °C until the grains achieve content of humidity ideal for storing around 13%. The grains were threshed and submitted to analysis of dry matter (DM), crude protein (CP), starch, prolamin (zein) and de nsity. The in situ degradability was conducted in four Nelore cattle fitted with rumen cannula. polyester bags were incubated in size 5.0 x 10.0 cm with a porosity of 50 ± 10 μm (Ankom Technology) containing 2.0 g samples of grain broken into four parts. We evaluated the following incubation times: 6, 12, 24 and 72 hours. Analysis of variance and the Scott-Knott test at 5% significance was conducted (R CORE TEAM, 2012).Hybrids farinaceous texture AG 1051, AG 4051 PRO and BM 3061 showed lower DM content (P<0.05) compared to hard (IMPACT VIP) and semi-hard hybrids (BJ 9450 PRO) except SG 6030 YG. The hard and semi-hard hybrids showed higher density than the hybrid farinaceous (P <0.05). Thus, defining two classes of hardness, hard or high density group (IMPACTO VIP, BJ 9450 PRO and SG 6030YG) and farinaceous or low density group (AG 1051, AG 4051 PRO and BM 3061). The low density group showed the highest CP (P <0.05). The starch content ranged from 68.0% in the hybrid IMPACTO VIP until 75.6% in the hybrid AG 1051. The hybrids of the low density showed the highest levels of zein in g/100g DM and also in relation to starch g/100g of starch. There were no differences in the in situ ruminal degradation of corn hybrids in the time of incubation evaluated.