Fabiana Villa Alves

Performance of Nellore heifers, forage mass, and structural and nutritional characteristics of Brachiaria brizantha grass in integrated production systems

Our objective was to evaluate production, nutritive value and carrying capacity of piatã grass (Brachiaria brizantha cv. BRS Piatã), and performance of Nellore heifers in agrosilvopastoral systems (ASPS) with three eucalyptus (Eucalyptus urograndis) tree densities, during winter, spring, summer, and fall. Three integrated systems were evaluated: ASPS-1 (357 trees ha−1), ASPS-2 (227 trees ha−1), and CON (5 trees ha−1). In each system, two sward heights were evaluated: short and tall. A total of 80 11-month-old Nellore heifers were randomly allocated in a randomized split-plot block, 3 × 2 factorial. Greater dry matter availability was observed on CON pastures during the fall season. Greater percentage of leaf lamina was detected on ASPS-1 with short sward height and greater during summer, compared with other seasons. A greater forage production was observed between tree rows and for tall sward height. Spring was the season with less forage nutritive value. Average daily gain was greater during summer and fall. Gain per hectare and stocking rate were greater on CON system and on ASPS-2. Pastures with short sward height had greater gain per hectare and stocking rate. Agrosilvopastoral systems with intermediate tree density seem to be a good choice for producers willing to diversify their revenue sources without decreasing animal production.

Growth curve of Nellore calves reared on natural pasture in the Pantanal

Weight-age and hip height-age relations of Nellore calves, from birth to 10 months old were fitted using a logistic model including sex and year of birth as fixed effects. Calves and their dams were reared on natural pasture using continuous grazing system. The crude protein content and total digestible nutrients were analyzed for pasture selected by the animals. The weights of the calves were adjusted to 205 days and 365 days. There were no significant effects of sex and birth year on the growth curve parameters, but there were significant effects of sex on hip height. The average weight (a parameter) at 10 months of age was 170 kg and the inflection point was observed at 93.5 days old. When weight-age and hip height-age curves were combined in the same graph, the intersection occurred at 142 days. The number of days to gain 160 kg from birth to 205 days of age (adjusted) and number of days to gain 240 kg from 205 days to slaughter was different between the birth years, which were probably due to the quality of the natural pastures. It is necessary to implement nutritional management strategies such as high quality pasture and/or feeding supplementation for calves once they reach three months of age.

Perfil lipídico da carne e gordura de suínos alimentados com milheto

The aim of this study was to evaluate the replacement of corn by millet in the diets of pigs on the lipid composition and cholesterol from subcutaneous fat and meat. It was used 48 castrated males, distributed on randomized experimental blocks design, with four levels of millet in the diet (0; 25; 50 and 75%), six replicate of two animals each. It was analyzed the lipid profiles of fat and meat by gas chromatography and the amount of cholesterol in the meat samples was determined following the extraction methodology. The increased level of millet in the diet of pigs reduced (P<0.05) the concentration of myristic, palmitic, palmitoleic and heptadecanoic acids and increased the concentration of linoleic acid in subcutaneous fat. The inclusion level of 50.82% of millet in the diet allowed maximum deposition of linolenic acid in fat. Levels of millet did not change the fatty acid profile and cholesterol content in pork. The level of 42.09% inclusion of millet in the diet results in the highest rate thrombogenic meat.

Desempenho, características qualitativas da carcaça e da carne de novilhas Brangus suplementadas em pastagem recebendo diferentes aditivos nutricionais

Aimed with this study to evaluate the efficiency of diets with different additives on the performance, carcass and meat traits of 150 Brangus heifers supplemented on pasture daily with 0,32% of live weight. The treatments were: supplement (no additives); seaweed flour (Lithothamnium calcareum) added to the supplement; vitamin E and organic selenium added to the supplement; protected fat added to the supplement; an application subcutaneously of vitamin D seven days before slaughter + supplement; and the association of vitamin E, organic selenium and protected fat added to the supplement + one dose of vitamin D seven days before slaughter. The animals were supplemented by 109,80 ± 11,71 days, when they were slaughtered when reached 337,95 ± 20,56kg. The experimental design was completely randomized with six treatments and 25 repetitions. The performance, the carcass and meat characteristics were not affected by the additives used. The average ribeye area of 52,00cm2 and the average fat thickness of 3,58 mm in the animals receiving the combination of additives did not differ from the values of the control treatment. The addition of vitamin D3 had no effect on shear force of Longissimus dorsi samples. The use of additives according to the protocols used did not improve the performance, the carcass and meat characteristics of cattle supplemented on pasture.

Características físico-químicas e composição centesimal de cortes cárneos de borregas confinadas e alimentadas com diferentes proporções volumoso: concentrado

Objetivou-se avaliar as caracteristicas fisico-quimicas e a composicao centesimal da carne de borregas confinadas recebendo diferentes relacoes volumoso (V):concentrado (C) (80:20; 60:40; 40:60 e 20:80) e os cortes carneos destes animais (paleta, lombo e do pernil). Foram utilizadas 24 borregas (mesticas) recem-desmamadas com peso vivo inicial medio de 23,1 ± 2,1kg, confinadas por 120 dias. Apos o abate, foram removidos os musculos Triceps brachii (paleta), Longissimus dorsi (lombo) e Semimembranosus (pernil) para representar os respectivos cortes. O aumento nos niveis de C nao influenciou a composicao centesimal dos cortes carneos e diminuiu a luminosidade (L*) e aumentou a tonalidade vermelha (a*). O lombo apresentou o menor teor de umidade (U) (699,7g/kg) e maior teor de extrato etereo (64,5g/kg), enquanto a paleta apresentou maior teor de U (738,7g/kg) e menor teor de PB (214,0g/kg), e o pernil apresentou o maior valor para PB (232,8g/kg) e valores intermediarios para U (716,3g/kg) e EE (40,1g/kg). O pernil forneceu a carne menos macia (FC=2,98kgf). Para as caracteristicas fisico-quimicas, o lombo e a paleta apresentaram carnes com maior valor de b* e o pernil e a paleta obtiveram maiores valores para a*. As diferentes proporcoes V:C nao alteram a composicao centesimal e proporcionam valores diferentes para L* e a*. Os cortes carneos apresentam diferencas na composicao quimica e nas caracteristicas fisicas.