Fernanda Barros Moreira

Fatty acid profile, and chemical composition of Longissimus muscle of bovine steers and bulls finished in pasture system

The objective of this work was to evaluate the conjugated linoleic acid content (CLA), the fatty acid profile, and the chemical composition of the Longissimus muscle (LM) of steers and bulls finished in pasture systems. Fourteen 1/2 Nelore×1/2 Aberdeen Angus cattle were studied. The animals were slaughtered at approximately 20 months of age, with an approximate final liveweight of 480kg. Moisture, ash, fat, crude protein, cholesterol, and fatty acid contents of Longissimus muscle were determined. Steer muscle had a higher lipid content (3.38%) than that of bulls (1.71%). Total n-3 fatty acids were higher in bulls. The amounts of CLA in steer and bull fat were similar, but the CLA content in steer muscle was higher (47.99mg100g(-1) in LM) than that in bull muscle (23.24mg100g(-1) in LM).

Sistemas para crescimento e terminação de bovinos de corte a pasto: avaliação do desempenho animal e características da forragem

The aim of this work was to evaluate the weight gain of growing and finishing steers, the life weight gain per hectare, and the forage quality in different grass production systems in the winter and summer. In the winter, the black oat pasture (BOP) and star grass (SGA) production systems were evaluated. In the summer, the millet (MIL), Mombaca (MOM), and star grass (SGA) production systems were evaluated and the effect of the production systems used in the winter on the animal performance in the summer was evaluated too. In the winter, the BOP system resulted in higher final body weigh (FW 381 kg) higher average daily gain (ADG 0,64 kg/day) and higher life weight gain/ha (LWG/ha 233 kg) when compared with SGA system (FW 332 kg, ADG -0,01 kg/day and LWG/ha -1,38 kg). The animals kept on BOP system in the winter had lower performance in the summer. For the growing animals, the BOP in the winter and MIL in the summer resulted in higher final body weigh (447 kg) when compared with BOP in the winter and MOM in the summer (414 kg) and SGA in the winter and MOM in the summer (397 kg). For the finishing steers, there was no difference between the systems evaluated. In the winter, the BOP and SGA presented means levels of 15 and 5% of crude protein (CP), 51 and 81% of neutral detergent fiber (NDF), 31 and 51% of acid detergent fiber (ADF), and 81 and 45% of in vitro dry matter digestibility (IVDMD). In the summer, the SGA, MOM and MIL presented means levels of 9, 9, and 18% of CP, 65, 64, and 54% of NDF, 40, 39, and 32% of ADF, and 55, 60, and 80% of IVDMD.

Comportamento ingestivo de ovinos recebendo dietas com diferentes níveis de bagaço de laranja em substituição à silagem de sorgo na ração

The objective of this study was to evaluate the effects of diets with different levels of fresh orange pulp in substitution to sorghum silage on eating behavior (feeding, rumination and idle)in sheep. Sixteen wethers, crossbred breeds averaging 28.27 kg BW (±2.41) were allotted to a randomized blocks design, with four treatments (0, 25, 50, and 75%), two blocks and two replicates per block. Animals were evaluated by observation during two consecutive days. In the first day, the average number of chewing per ruminal bolus and the average time spending in the chewing per ruminal bolus were evaluated during three periods (8 to 10 hours, 14 to 16 hours and 18 to 20 hours). In the second day, the behaviour was visually determined during 24 hours with five minutes intervals to determine the times spent in idle, feeding, rumination. There was not difference for the time spent with feeding in minutes day and in minutes/kg of DM and NDF. The time spent in rumination and idle in minutes day showed a quadratic effect in function of increased levels of fresh citrus pulp in the diets. The time spent in rumination, in minutes for kg MS, presented decreased linear effect and the time with rumination in minutes/kg NDF there was not difference. No differences on daily feeding number, total chewing time, number of rumination bolus, number of rumination chews per bolus and rumination chews time per bolus were observed. The number of rumination periods and number of rumination chews showed decreasing linear effect.

Degradabilidade in situ da matéria seca, proteína bruta e fibra em detergente neutro de algumas gramíneas sob pastejo contínuo

Foram avaliadas a cinetica de degradacao e a degradabilidade efetiva (DE) da materia seca (MS), fibra em detergente neutro (FDN) e proteina bruta (PB) com ou sem correcao para contaminacao por proteina de origem microbiana da aveia preta, capim-Mombaca, grama estrela roxa e milheto, provenientes de pastagens sob pastejo continuo. A forragem foi colhida em diferentes pontos do piquete a cada 14 dias para aveia preta e, a cada 28 dias, para as outras forrageiras. Os alimentos foram incubados no rumen em sacos de nailon nos tempos 0, 6, 12, 24, 48, 72 e 96 h. Foram utilizados tres bovinos machos, inteiros, com 350 kg PV. Para correcao da contaminacao por proteina microbiana nos residuos de incubacao, foi determinado o teor de proteina insoluvel em detergente neutro. Para MS, a aveia preta e o milheto apresentaram maior fracao soluvel (a = 32 e 24%) e maior DE a 5%/h (53 e 48%). A grama estrela roxa de inverno apresentou menor fracao soluvel (14%) e menor DE da MS a 5%/h (23%). Para PB corrigida, a aveia preta e o milheto apresentaram maior DE a 5%/h (80 e 75%) em relacao as outras gramineas (DE media de 67%). A taxa de degradacao e a DE da PB foram subestimadas quando nao foi feita a correcao para contaminacao microbiana. A porcentagem de contaminacao foi semelhante entre as forrageiras e para os diferentes tempos de incubacao, com valores medios de 52%. Para FDN, a aveia preta apresentou maior DE a 5%/h (40%), seguida pelo milheto (35%), estrela roxa no verao (23%), estrela roxa no inverno (19%) e Mombaca (16%). A aveia preta e o milheto apresentaram maior fracao soluvel, maior taxa de degradacao e maior DE da MS, PB e FDN em relacao a grama estrela e ao capim-Mombaca.