ObjectiveIsoquinoline Alkaloids, derived from one plant (Macleaya cordata) can be an alternative when it is desired to increase performance in feedlot cattle. However, results on these nutritional additives in high energy diets in ruminants are still incipient in literature. In this context, the objective of this study was to evaluate performance and carcass traits of feedlot bulls supplemented with sanguinarine, the main alkaloid presents in Macleaya cordata in high energy density diets.MethodsThirty-two crossbred Angus-Nelore bulls with mean initial body weight of 365±10 kg and mean initial age of 11±3 months were used. The experiment lasted 119 days, with 14 days of adaptation and 105 experimental days. Experimental diet consisted of 85% whole corn grains and 15% protein-vitamin-mineral nucleus and supplied ad libitum. Treatments consisted of a control diet (CON) and a diet with sanguinarine supplementation (SAN) at a dosage of 4 g of product sufficient to provide 6 mg of sanguinarine/d. Experimental design was completely randomized.ResultsDry matter intake, average daily gain and feed conversion were similar (p>0.05) between treatments. However, SAN group animals had higher carcass yield (p = 0.045) and were more efficient in the transformation of dry matter consumed in carcass gain (p = 0.046) than CON. In addition, haptoglobin, increased throughout feedlot duration meaning high challenge for the animals due to the diet, but this behavior was similar (p>0.05) between treatments.ConclusionSanguinarine produced positive results in relation to carcass yield and could be used as an additive for bulls fed diets receiving high energy density diet.

O trabalho foi realizado com objetivo de avaliar a produtividade, a composição morfológica e bromatológica, bem como a taxa de desaparecimento ruminal da matéria seca (MS) da silagem de milho (Zea mays) cultivado sob níveis crescentes de adubação nitrogenada em cobertura. Na semeadura do milho foi aplicado diretamente no sulco de plantio 500 kg ha-1 de adubo com a formulação 12-31-17 (NPK) para todos os tratamentos, e em estágio fenológico V5 foi realizada a adubação em cobertura diferenciada, utilizando as seguintes dosagens: T1, 135,0 kg de N ha-1 (NPK: 27-00-00); T2, 175,5 kg de N ha-1 (NPK: 27-00-00); e T3, 225,5 kg de N ha-1 (NPK: 27-00-00). O aumento da dose de adubação nitrogenada em cobertura proporcionou um menor número de folhas secas no momento da colheita. Além disso, a maior dose de nitrogênio lançada em cobertura (225,5 kg ha-1) proporcionou uma fração fibrosa de maior digestibilidade em relação aos demais tratamentos (73,29%). A dose de 175,5 kg de N ha-1 proporcionou plantas com melhor taxa de degradabilidade ruminal (0,99% hora-1) e quilos de matéria seca digestíveis por área (15081 kg MS ha-1), enquanto a menor dose utilizada (135,0 kg ha-1) gerou os melhores níveis de FDN (55,76%), FDA (25,75%) e CNF+EE (34,66%) sem afetar a produtividade e a composição morfológica da planta. Os resultados do presente trabalho implicam dizer que a cultura do milho responde de maneira diferente conforme o aumento dos níveis de nitrogênio utilizado em cobertura, onde, cada nível traz benefícios distintos em relação a qualidade bromatológica.

This study aimed to evaluate the performance, apparent digestibility of diet, ingestive behavior which occurred in two moments, carcass traits, being evaluated constituent and non-carcass components, and also the effect the yeast culture could promote in the peripheral temperature of rumen, hull and body temperature. The diets consisted of a constant ratio of 50% forage (maize silage) and 50% concentrate. Thirty-six steers, ½ Angus Nelore, with average age of 11 months and average initial body weight of 339.5±10kg were used in the experiment. The inclusion of yeast culture promoted a higher daily dry matter intake (8.83 vs 9.35kg day-1) and, consequently, a better daily weight gain (1,143 vs. 1,325kg day-1) in the initial feedlot phase, with no difference in other periods. The apparent digestibility of the diet containing yeast culture was higher than the control diet (69.69 versus 68.32%, respectively), and its use did not interfere with the feeding behavior of the animals. Based on our findings, supplementation with yeast culture may bring positive results in the initial feedlot phase.

RESUMO - O objetivo foi avaliar a produção de biomassa e a composição física e química da planta de três híbridosde milho simples (P2530H, P30R50H e P30B39H) associadas a três densidades de plantio (60, 70 e 80 mil plantas ha-1) e três locais de cultivo (Local A, B e C). De forma isolada, as maiores produções de biomassa seca e de grãos, respectivamente, foram observadas na densidade de 80 mil plantas ha-1 (30.067 e 14.020 kg ha-1) e no local C (30.157 e 13.895 kg ha-1). Com relação aos híbridos estudados, houve influência do local de cultivo em que o híbrido P2530H foi superior para produção de biomassa seca e de grãos nos locais A e C (28.600 e 31.485 kg ha-1) e o híbrido P30B39H no local B (30.356 e 14.760 kg ha-1). Quanto à avaliação bromatológica, o local B gerou os maiores teores de proteína bruta (7,00%), matéria mineral (2,74%), fibra em detergente neutro (65,33%) e fibra em detergente ácido (36,10%), enquanto obteve os menores teores de nutrientes digestíveis totais (62,57%), comparado aos locais A e C (65,85 e 65,47%, respectivamente). De maneira geral, a densidade de cultivo não alterou os valores nutricionais das silagens dos diferentes híbridos de milho e locais de cultivo. Palavras-chave: altitude de cultivo, produção de biomassa seca, fibra em detergente neutro, NDT. HYBRID PERFORMANCE FOR MAIZE SILAGE CULTIVATED IN DIFFERENT PLACES WITH THREE POPULATION DENSITIESABSTRACT - The aim of this work was to evaluate the performance of three maize hybrids (P2530H, P30R50H e P30B39H) with three population densities (60, 70, and 80 000 plants ha-1) in three grown locations (A, B e C). In isolation, the greater dry biomass and grain yield, respectively, were observed in the density of 80,000 plants ha-1 (30,067 and 14,020 kg ha-1) and place C (30,157 and 13,895 kg ha-1). Regarding the hybrid, there was a direct influence of the local cultivation, and hybrid P2530H had the higher dry biomass and grain production in the location A and C (28,600 and 31,485 kg ha-1), and the hybrid P30B39H on location B (30,356 and 14,760 kg ha-1). In the bromatological assessment, the location B obtained the highest CP (7.00%), MM (2.74%), NDF (65.33%) and ADF content (36.10%), while it had the lower levels of TDN (62.57%) compared to locations A and C (65.85 and 65.47%, respectively). In general, the plant density did not change the silage nutritional values in maize hybrids associated with different places. Keywords: sowing altitude, dry biomass, neutral detergent fiber, TDN.

he objective of this study was to evaluate the production and physical composition of three maize hybrids (Zea mays, L.) for silage production at six maturity stages. The hybrids evaluated were Maximus VIP3, Defender VIP and Feroz VIP. The experiment was conducted in a completely randomized block design with four replicates. The mean plant heights observed at harvest time (2.33 m, 2.45 m and 2.40 m) demonstrated that all materials were medium-sized hybrids. A positive correlation was observed between plant height and height of the ear insertion, varying from 0.86 for the Feroz VIP hybrid to 0.88 for the Maximus VIP3 hybrid, but these two variants had no correlation with the productivity data. There was a significant difference for the production of fresh biomass at the R1, R2 and R5 stages, with Maximus VIP3 obtaining the highest yields. The proportion of grains in the physical composition of plant varied between hybrids, where Maximus VIP3 and Defender VIP (482.2 and 461.7 g kg-1, respectively) were superior to Feroz VIP (429.7 g kg-1). With the advancement of maturity, there was a decreasing linear behavior for stem and leaf participation, with reductions of 3.8 g kg-1 and 4.5 g kg-1, respectively, per day (R2 = 0.79 and 0.80, respectively), quadratic behavior for bracts and corncob and a linear increase in grain participation in the plant structure, with an increase of 7.7 g kg-1 per day (R2 = 0.88). In general, the three hybrids present good characteristics for silage production and permit harvesting in the hard grain stage, allowing the addition of starch in relation to the farinaceous grain stage.