The objective of this study was to evaluate the potential of in vivo bioimpedance analysis (BIA) as a method to estimate body composition in lambs. Thirty-one Texel x Ile de France crossbreed ram lambs were slaughtered at pre-determined intervals of average weights of 20, 26, 32, and 38 kg. Before the slaughter of the animals, their body weight (BW) and body length (BL) were measured. The values for resistance (Rs) and reactance (Xc) were collected using a single-frequency BIA equipment (Model RJL Quantum II Bioelectrical Body Composition Analyzer). The BIA main variables such as body bioelectrical volume (V), phase angle (PA), resistive density (RsD), and reactive density (XcD) were then 2 calculated. The soft tissue mass of the right-half cold carcass was analyzed in order to determine its chemical composition. Multiple regression analyses were performed using the lamb body composition as dependent variables and the measurements related to bioimpedance as independent variables. The best regression models were evaluated by cross-validation. The predictive model of moisture mass, which was developed by using XcD and V, accounted for 84% of its variation. Resulting models of percentage moisture (R 2 = 0.79), percentage lean mass (R 2 = 0.79), percentage fat (R 2 = 0.79), and fat mass (R 2 = 0.87) were obtained using RsD and V. Furthermore, the values of RsD regarding V, and PA in the prediction models accounted for 91% and 89% of variation in protein mass and lean mass, respectively. Bioimpedance analysis proved to be an efficient method to estimate the body composition of lambs slaughtered at different body mass stages.

Our objective was to evaluate performance and fatty acid contents of the meat of Holstein veal fed in feedlots and slaughtered at four different pre-determined live weights (140, 180, 220, and 260 kg). Twenty-three non-castrated calves with initial average ages of 58 days and 57 kg live weight were used in this study. Average daily gain, dry matter intake, nutrient intake, cold carcass weight, cold carcass yield, scraps, and fat thickness improved with increasing slaughter weight. However, C18:0, C22:0, C18:2Trans10Cis12, C18:1n9Cis acids, sum of unsaturated fatty acids, and lipid content decreased with the increase in slaughter weight. Raising the slaughter weight of Holstein calves from 144 to 260 kg improves the performance of animals, mainly due to the increase in their intake capacity. However, this increase in slaughter weight does not result in significant changes in the fatty acid composition of the meat.

No abstract

The objective of this study was to evaluate the weight of the empty body and non-integrant components of Holstein calves carcass, kept in confinement system or pasture, slaughtered at different weights. We used 43 Holstein calves, entire, age and initial body weight of approximately 58 days and 57 kg, distributed entirely at random in confinement or cultivated pasture. In feeding systems, it was prestipulated four slaughter weights (SW -140, 180, 220 and 260 kg of live weight). In confinement, were provided corn silage and concentrate based on corn meal and soybean meal, in the ratio 40:60. The other animals in ryegrass pasture, followed by pearl millet, were fed based in supplementation of corn bran and soybean meal to 1% of live weight. The EBW showed linear growth with increasing slaughter weight (SW), as well as income from hot and cold carcass and there was no effect in relation EBW/ SW. The leather, the scraps, the head, the legs, as well as the sum of external components showed growth in its absolute weight as the weight increased at the slaughter of animals. In relative terms, the hot and cold carcass yields were inversely correlated with the relative weights, as well as external components (-0.68 and -0.81), the heart (-0.35 and -0, 38) lungs (-0.53 and -0.53), the sum of the gastrointestinal tract (-0.75 and -0.77), the sum of vital organs (-0.71 to -0.75) respectively in feedlot and pasture. This is due to the different ages that the animals were slaughtered (200; 237; 251 and 263 days of age), due to prestipulate weights. The absolute weights of heart, kidney, lungs, liver, spleen, gall bladder, reproductive tract and gastrointestinal tract accompanied the increase in weight at animal's slaughter. However, when grouped, showed no difference related to the increase in weight at slaughter. The differences presented by the liver, trachea and spleen were sufficient to alter the absolute and relative weights of the set of internal components, where the animals finished on pasture had higher weight. The animals finished on pasture had higher absolute weights (0.48 against 1.18 kg) and relatives (0.31 and 0.79%). ResumoO objetivo do trabalho foi avaliar o peso do corpo vazio (PCVZ) e os componentes não-carcaça de 43 bezerros holandeses, não castrados, com idade de 58 dias e peso médio de 60 kg, distribuídos ao acaso em confinamento ou pastagem cultivada. Em cada sistema, foram pré-estipulados quatro pesos de abate 180, 220 e 260 kg de peso vivo). No confinamento, foram fornecidos silagem de milho e concentrado à base de farelo de milho e farelo de soja, na relação 40:60. Os demais animais em pastagem cultivada de azevém e milheto, com suplementação a 1% do peso vivo. O PCVZ apresentou crescimento linear com o aumento do peso de abate, assim como os rendimentos de carcaça quente e fria e não houve efeito na relação PCVZ/PAB. O crescimento absoluto dos componentes externos foi proporcional ao aumento de peso. Em peso relativo ao PCVZ apenas a cabeça e as patas apresentaram diminuição em resposta ao ...

Given the increasing availability of new cultivars with high yield potential, the use of annual tropical forages to improve cattle production systems is increasing and therefore warrants more research. The objective of this study was to quantify the influence of feed supplementation and nitrogen fertilization on the diurnal ingestive behaviour of crossbred steers (zebu x taurine), maintained on a pasture of Alexander grass (Urochloa plantaginea). The treatments included the application of nitrogen fertilizer at 100 kg/ha; at 100 kg/ha + supplemented feed of wheat bran (0.5% of bodyweight); and at 200 kg/ha. The study used a completely randomized design with three replications. The paddock size was 0.7 ha. Data were analysed by fitting mixed models. The times spent resting, ruminating and consuming water were not different among treatments. However, time spent grazing significantly differed. On average, steers given supplemented feed spent less time grazing (297 min/day) than steers without the supplemented feed (345 min/day). Steers in the pasture with supplementation showed a significantly greater number of daytime bites (2029 bites) than steers in the 200 kg nitrogen treatment (1715 bites). Supplementation reduced grazing time without altering other behaviour variables. The number of daily bites was lower on the pasture with the higher nitrogen level.

The use of animals from dairy farms is an alternative to meat production since it provides an increment of total income for farmers. This study aims to evaluate the performance of Holstein calves finished in two feeding systems (feedlot or pasture). Forty-three animals with 58 days old and 57 kg were divided in two treatments: 23 animals finished in feedlot with corn silage plus concentrate based on corn and soybean meal (40:60); 20 animals kept in cultivated pastures according to the period of the year: Italian ryegrass (Lolium multiflorum) and pearl millet (Pennisetum americanum) with supplementation with the same feedlot-concentrate at 1% body weight. Animals were slaughtered with 200 kg. Dry matter and nutrient intake were determined, with the use of chromium oxide for estimating pasture intake. Feedlot animals had greater total intake and total digestible nutrients, resulting in higher average daily gain (0.949 vs 0.694 kg day -1 ). Crude protein intake, neutral detergent fiber and feed conversion did not show significant differences. Holstein calves have improved performance when finished in feedlot.

The aim of this study was to assess the influence of different finishing systems on the in vivo measurements, quantitative and qualitative carcass characteristics, commercial cut ratio, and shoulder tissue composition of lambs. Thirty-two male lambs were distributed in four finishing systems with eight replications each, as follows: suckling lambs on pasture; suckling lambs in confinement, with access to creep-feeding containing corn bran and soybean meal; weaned lambs fed roughage, characterized by ad libitum supply of alfalfa hay; and weaned lambs fed concentrate, composed of oat grain and soybean meal. The lambs were slaughtered as they reached the pre-set live weight at slaughtering of 30 kg. Most of the in vivo biometry variables were not significant (P > 0.05) when comparing the finishing systems, except for hindlimb height and thoracic perimeter. Regarding the quantitative carcass characteristics, all variables differed (P < 0.05) between systems, except for carcass length, leg width, and subcutaneous fat thickness. For the qualitative carcass characteristics, only the fatness and carcass conformation presented significant differences (P < 0.05). Most in vivo measurements and the proportion of carcass cuts were not influenced by finishing systems. Weaned lambs fed an exclusive concentrate diet presented leaner carcasses with an inferior conformation when compared to the other finishing systems. Suckling lambs in confinement presented shoulders with a higher fat deposition when compared to those weaned. Suckling lambs both on pasture and in confinement presented a superiority in the quantitative carcass characteristics when compared to weaned lambs.

No abstract