Alexandre Nunes Motta de Souza

Manipulação da altura de corte da planta de milho (Zea mays, L.) para ensilagem visando a produção do novilho superprecoce

The experiment was conducted with the objective to evaluate the performance of feedlot finished calves, fed with silages of AG-5011 corn hybrid harvested with different cutting height: low cut (20 cm) and high cut (42 cm). Twelve Braford calves with an average age of seven months and average live weight of 209 kg, were used. The feedlot period was 126 days, divided in two periods of the 63 days. The roughage:concentrate ratio was 60:40 and 50:50 for the first and second periods, respectively. The high cut silage showed higher IVOMD (66.67 vs 58.60%) and lower NDF (41.47 vs 47.80%). Significant interaction was observed between cutting height and evaluation period for dry matter intake (DMI) expressed per 100 kg of live weight and per unit of metabolic weight, digestible energy intake (DEI), weight gain (ADG), feed conversion (FC) and energy efficiency (EE). Animals fed with the high cut silage during the first period presented higher ADG (1.352 vs 1.198 kg) and better FC (4.82 vs 5.39 kg of DM/kg LW) than animals fed with the low cut silage. However, with the reduction of the roughage:concentrate ratio to 50:50 during the second period, the ADG (1.228 vs 1.336 kg) and FC (6.43 vs 6.34 kg of DM/kg LW) were similar. Slaughter and cold carcass weight, dressing percentage and subcutaneous fat thickness were similar, being, respectively, 371.8 kg; 195.3 kg; 52.46%; and 5.7 mm for the higher cut and 368.2 kg; 195.7 kg; 53.08%; and 3.7 mm for the lower cut.

Efeito do Grupo Genético e da Heterose na Composição Física e nas Características Qualitativas da Carcaça e da Carne de Vacas de Descarte Terminadas em Confinamento

Carcass physical composition and meat qualitative characteristics of cull cows from two breeding systems, straightbreds (Charolais and Nellore) and crossbreds F1 1/2 Charolais-Nellore and 1/2 Nellore-Charolais, were evaluated. The cows were feedlot finished during 80 days and fed with 65% roughage (sorghum silage) and 35% concentrate, in dry matter basis. Charolais cows showed carcass with higher muscle (65.2 vs 58.8%) and bone (15.36 vs 13.7%) percentages, higher muscle (166.5 vs 139.61 kg) and bone (38.84 vs 32.34 kg) production than Nellore cows. Meat from Charolais cows also exhibited better color (3.75 vs 3.14), tenderness (6.22 vs 5.34) and juiciness (6.16 vs 5.56). Nellore cows showed higher fat percentage (27.95 vs 19.85%), total fat production (66.7 vs 51.2 kg) and higher meat thawing losses (6.15 vs 4.18%). Crossbreds F1 females were superior to the straightbreds for fat percentage (26.74 vs 23.9%), total fat production (72.79 vs 58.95 kg), however, showed lower muscle percentage in the carcass (59.59 vs 62.02%), being the heterosis values 11.88, 23.48 and ¾3.92%, respectively. Meat qualitative characteristics were not affected by the breeding system.

Características agronômicas produtivas, qualidade e custo de produção de forragem em pastagem de azevém (Lolium multiflorum Lam) fertilizada com dois tipos de adubo

One experiment was conducted, with the purpose to evaluate the production, quality and the production cost of forage of ryegrass, in continuous grazing, fertilized with two types of fertilizer: Organic-mineral (FOM) and chemical (FC) applied as top dressing. The pasture was implanted in 04/24/1999, with top-seeding, and the level of fertilizer was300kg ha-1 of FOM formula 06-08-08 or FC formula 10-18-20. No significant interaction between fertilizer and evaluation period was observed for the variables studied. The fertilizer sources did not affect the percentage of dry matter (DM) in the residue (22.6 vs 22.2%), the accumulation rate of dry matter (72.3 vs 63.2kg ha-1 of DM), the total forage production (7518 vs 6801 kg ha-1 of DM), the percentage of crude protein (12.8 vs 12.7%), the neutral detergent fiber (57.4 vs 57.4%) and acid detergent fiber (31.0 vs 32.3%), for FOM and FC, respectively. The total cost of the pasture was of 225.90 and 253.50 R

Productivity and reproductive performance of grazing beef heifers bred at 18 months of age

ha-1, where the fertilizer represented 37.6 and 44.4%, respectively, for FOM and FC. The production cost of the pasture DM was 0.030 and 0.037 R

Avaliação da Silagem de Diferentes Híbridos de Sorgo (Sorghum bicolor, L. Moench) por meio do Desempenho de Novilhos de Corte Confinados

kg-1, for FOM and FC, respectively.

Comportamento ingestivo de novilhas de corte em pastagem de gramíneas anuais de estação quente

The experiment was carried out to evaluate the performance and body development of beef heifers reared from 15 to 18 months of age on Pearl millet (Pennisetum americanum), Alexandergrass pasture (Urochloa plantaginea) or native pasture invaded by Annoni-2 grass (Eragrostis plana Nees). The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two replications. The grazing method was continuous with variable stocking rate in order to maintain the sward height at 40 cm. Masses of leaf, stem and dead material, crude protein and neutral detergent fiber were similar between Pearl millet and Alexandergrass. Average daily gain, stocking rate, live weight gain per hectare, body weight, body condition score, weight-to-height ratio and reproductive tract score of the heifers kept on annual summer pastures (Pearl millet or Alexandergrass) were superior, compared with the heifers on Annoni-2 grass pasture.

Efeitos do livre acesso de bezerros ao creep-feeding sobre os esempenhos produtivo e reprodutivo de vacas primíparas

The experiment was conducted to evaluate the parameters of dry matter intake, weight gain, feed conversion and energy efficiency of feedlot steers, fed with four diets that included silage of hybrids of sorghum with different agricultural behavior: AGX-213 and AG-2002 (forage), AGX-217 and AG-2005E (double purpose). Forty-eight steers with an average age of 19 months and average live weight of 316 kg, were used. The roughage:concentrate ratio was 63:37, for all the diets tested. No significant interaction was observed between roughage source and feedlot evaluation period. The sorghum silage of hybrid AG-2005E caused higher dry matter intake, digestible energy intake, daily weight gain and better feed conversion and energy efficiency than the other genotypes. The contrast analysis showed that the silage of the forage hybrids (AGX-213 and AG-2002) caused a significant reduction of the daily voluntary dry matter intake (8.84%) and digestible energy intake (12.11%) in comparison to the silage of the double purpose hybrids (AGX-217 and AG-2005E). Steers fed with silage of the double purpose hybrids showed higher daily weight gain (1.163 vs .943 kg) and were more efficient (P<.05) in converting dry matter intake and digestible energy intake into weight gain (7.65 vs 8.73 kg of DM/kg LW and 19.76 vs 21.84 Mcal/kg LW).

Desempenho de bezerros desmamados precocemente, mantidos em pastagem de capim elefante (Pennisetum purpureum, Schum), com diferentes níveis de suplementação

The experiment was carried out with the objective of evaluating attributes of pearl millet (Pennisetum americanum) and Alexander grass (Urochloa plantaginea) pastures and to relate them with ingestive behavior of beef heifers. The experimental design was complete randomized, with repeated measures over time, with two treatments and two area replications. Grazing method was continuos stocking and variable number of animals to keep canopy height at 40 cm. Mass of leaf blade, stem and dead material, forage accumulation rate, leaf/stem ratio, offer of forage and leaf blade, content of neutral detergent fiber were all similar in pearl millet and Alexander grass. Alexander grass presented higher stem bulk density in the 0-15 cm stratum. The density of dead material in the 0-15 cm stratum and the densities of leaf blade, stem and dead material in 15-30 cm, 30-45 cm and more than 45 cm in height strata were similar in millet and Alexander grass. The ingestive behavior of heifers, measured by grazing, rumination and idle times, bite rate, bite weight, bite per feeding station, feeding stations per minute and rate of displacement was similar when animals were kept in pearl millet or alexandergrass pastures. Multiple regression equations, considering atributes of pasture, grazing and climate showed determination coefficients greater than 0.70 for grazing time, bite mass, bite by feeding station, feeding station per minute, rate of displacement and they can be used as predictors of the ingestive behavior of beef heifers in pearl millet or alexandergrass pastures.The experiment was carried out with the objective of evaluating attributes of pearl millet (Pennisetum americanum) and Alexander grass (Urochloa plantaginea) pastures and to relate them with ingestive behavior of beef heifers. The experimental design was complete randomized, with repeated measures over time, with two treatments and two area replications. Grazing method was continuos stocking and variable number of animals to keep canopy height at 40 cm. Mass of leaf blade, stem and dead material, forage accumulation rate, leaf/stem ratio, offer of forage and leaf blade, content of neutral detergent fiber were all similar in pearl millet and Alexander grass. Alexander grass presented higher stem bulk density in the 0-15 cm stratum. The density of dead material in the 0-15 cm stratum and the densities of leaf blade, stem and dead material in 15-30 cm, 30-45 cm and more than 45 cm in height strata were similar in millet and Alexander grass. The ingestive behavior of heifers, measured by grazing, rumination and idle times, bite rate, bite weight, bite per feeding station, feeding stations per minute and rate of displacement was similar when animals were kept in pearl millet or alexandergrass pastures. Multiple regression equations, considering atributes of pasture, grazing and climate showed determination coefficients greater than 0.70 for grazing time, bite mass, bite by feeding station, feeding station per minute, rate of displacement and they can be used as predictors of the ingestive behavior of beef heifers in pearl millet or alexandergrass pastures.

COMPORTAMENTO PRODUTIVO E CUSTO DE PRODUÇÃO DE HÍBRIDOS DE SORGO (Sorghum bicolor, L. MOENCH) PARA SILAGEM

The research evaluated the effects of the creep-feeding on the productive and reproductive performance of the primiparous cows, maintained on improved natural pasture with ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens Lam.) and cornichao (Lotus corniculatus Lam. cv. Sao Gabriel). A completely randomized experimental design composed by four treatments according to 2 x 2 factorial arrangement (two sex: cows suckling male or female calves; two systems of feeding: cows suckling male or female with or without access creep-feeding, totalizing 16 experimental units. The primiparous cows of the creep-feeding system showed body weight and corporal condition, in the end of the experiment, higher in relation to the ones without creep-feeding system (412 kg and 3.94 versus 399 kg and 3.77, respectively). Cows in the creep-feeding system showed average daily weight gain higher than the cows with calves without access to creep-feeding (0.549 vs. 0.449 kg/day). Creep-feeding and the sex of calves did not influence the pregnancy rate of primiparous cows.

DESEMPENHO VEGETATIVO E QUALITATIVO DO SORGO FORRAGEIRO (Sorghum bicolor X Sorghum sudanense) EM MANEJO DE CORTES

The experiment was conducted in Regiao Central do Rio Grande do Sul, in order to evaluate the performance of the steers in elefantegrass (Pennisetum purpureum Schum.), under continuous grazing associed with different sources supplementation: 0.3; 0.7; 1.1 and 1.5% of live weight day-1 (LW). Thirty two Charolais (C), Nellore (N), 5/8 CN e 5/8 NC steers calves with na average age of one hundred twenty day, with average live weight of 98.5kg. The supplementation period was 84 days, divided in four periods of the 21 days. The forage mass of the pasture of elefantegrass presented average values of dry matter 20.44% (DM), crude protein 10.67% (CP) e 7.006.0kg de DM ha-1 during experimental period. The proportion of green leaf matter was of 22.62% representation an green leaf dry total of 1.650.8kg de DM ha-1. No significant interaction was observed between sources supplementation and evaluation period for average weight gain (ADG). Observed what the ADG was of 0.365 kg, no obtained significant difference between the sources, with ADG of 0.279, 0.380, 0.338 e 0.466kg day-1 for 0.3, 0.7, 1.1 e 1.5% do LW, respectively. In the analysis of the periods of supplementation, the GMD was bigger (P<.05) in the third period (0.545kg day-1) and minor (P<.05) in the fourth period (0.145kg day-1) comparatively to the first (0.342kg day-1) and to the second (0.431kg day-1) periods.