Edson Luis de Azambuja Ribeiro

Características de carcaça e qualidade da carne de bovinos de corte de quatro grupos genéticos terminados em confinamento

The objective of this study was to evaluate carcass traits and meat quality of Tabapua and Bonsmara purebred steers, and crossbred ½ Bonsmara + ½ Nellore and ½ Bonsmara + ¼ Red Angus + ¼ Nellore steers. Five animals were used in each genetic group. The average age and weight at the beginning of the experiment were 22 months and 394±21 kg. All animals received the same diet, which was composed of sugar cane silage and a commercial ration, in a ratio of 55 and 45% (dry matter basis), respectively, with 14.99 crude protein and 59.84% total digestible nutrients. There were no differences between the genetic groups for cold carcass weight or percentages of commercial cuts (forequarter, hindquarter and sidequarter) at slaughter. Bonsmara steers presented the greatest ribeye area and percentage of muscle, and the lowest percentage of fat in the carcass. Crossbred ½ Bonsmara + ½ Nellore animals presented greater back fat thickness (BFT) than Bonsmara and Tabapua animals; however, all genetic groups presented BFT greater than the minimum (3 mm) required by the meat industry. There was no difference in the meat centesimal composition between genetic groups. Meat from Bonsmara, ½ Bonsmara + ½ Nellore and ½ Bonsmara + ¼ Red Angus + ¼ Nellore presented greater tenderness than that from Tabapua steers. The longissimus fat acid profile did not differ between the genetic groups studied. Meat from Bonsmara and crossbred ½ Bonsmara + ½ Nellore and ½ Bonsmara + ¼ Red Angus + ¼ Nellore animals presented greater quality than that from Tabapua steers.

Cinética ruminal da degradação de nutrientes da silagem de milho em ambiente ruminal inoculado com diferentes aditivos

Four bulls fitted with ruminal cannula were used in a 4 x 4 Latin square design to evaluate the effects of different ruminally inoculated additives on the degradation kinetics of DM, CP, and NDF of corn silage (CS). The treatments were: control CS incubated in rumen with no additive; LB - CS incubated in rumen inoculated with five grams of dehydrated and lyophilized ruminal and intestinal bacteria (Ruminobacter amylophilum: 3.0 x 1011 ufc/kg; Fibrobacter succinogenes: 3.0 x 1011 ufc/kg; Succinovibrio dextrinsolvens: 4.4 x 1011 ufc/kg; Bacillus cereus: 3.5 x 1011 ufc/kg; Lactobacillus acidophilus: 3.5 x 1011 ufc/kg and Streptococcus faecium: 3.5 x 1011 ufc/kg); CE - CS incubated in rumen inoculated with 15 grams of cellulolytic enzymes (xylanase; 10%); and SM - CS incubated in rumen inoculated with three milligrams of sodium monensin. The LB and CE treatments did not affect the potentially degradable b fraction of CS nutrients. However, the SM treatment reduced the DM b fraction (51.01%) and the potential degradability of CS (72.33%). Use of SM resulted in the greatest NDF indigestible fraction reducing NDF disappearance after 48 hours of ruminal incubation. It can be concluded that the different additives did not improve the effective degradability of CS DM, CP, and NDF.