Lisiane Furtado da Silva

Composição corporal e exigências nutricionais de energia e proteína para cordeiros em crescimento

This work was conducted with the objective to determine the body composition for fat, protein and ash, the net requirements of energy and protein for weight gain, and the requirements of metabolizable protein of growing lambs. Twenty-two male lambs, sired by Texel males, from crossbreed Texel x Ideal dams were used. Four lambs were slaughtered at the beginning of the experiment (24 hours after birth) and groups of six lambs were slaughtered at weaning, at 28 and 33 kg of live weight. The prediction equations of the corporal composition of protein, fat, ash and energy were fitted, according to the ARC (1980), by the regression of log of fat, protein, ash and energy, content in the empty body, in relation to the log of empty body weight (EBW). The net requirements of protein and energy for weight gain were obtained based on the prediction equations of body composition, while of metabolizable protein requirements were estimated in agreement with the AFRC (1993). The body contents of protein, fat, energy and ash for lambs from 5 to 30 kg EBW. ranged from 141.69 to 186.24 g/kg EBW; 24.49 to 158.11 g/kg EBW; 1088.75 to 2451.55 Kcal/kg EBW, and 27.55 to 33.70 g/kg EBW, respectively. The estimated net requirements for weight gain were: energy, from 399.93 to 892.21 kcal/250g of gain, and protein from 40.98 to 53.70 g/250g of gain, for lambs from 5 to 30 kg of EBW, respectively. The requirements of metabolizable protein for animals from 5 to 30 kg live weight ranged from 79.09 to 121.13 g/250g of gain.

Crescimento de regiões da carcaça de cordeiros abatidos com diferentes pesos

This work was performed at the Ovine Section of Animal Science Department, at Federal University of Santa Maria, Brazil. The purpose of this experiment was to determine the growth of the carcass cuts and percentages in relation to the empty body weight and cold carcass weight of lambs slaughtered at different weights. Twenty-two intact male lambs, sired by Texel males, from crossbreed Texel-Ideal dams were used. Four lambs were slaughtered at the beginning of the experiment (24 hours after birth) and three groups of six lambs were slaughtered at weaning and when reaching the weight of 28 and 33kg. The lambs were confined in individual stall together, with their respective mothers until weaning (45 days of age). To study the growth of the different cuts of the carcass, regression equation of the log. of the weight of each part, as a function of the log. of the empty body weight or cold carcass weight were fitted. The percentages of hindquarter, shoulder and neck in relation to the empty body weight were similar (P>0.05) in the weights studied, and of rib and backbone were different (P<0.05). In relation to the cold carcass weight the percentage of hindquarter, rib and neck showed difference (P<0.05). Among the cuts, the rib was late matured and the other cuts were early matured.

Crescimento de cordeiros abatidos com diferentes pesos: 2. Constituintes corporais

O experimento foi realizado no Setor de Ovinocultura do Departamento de Zootecnia da Universidade Federal de Santa Maria, com o objetivo de determinar o crescimento de orgaos e outros constituintes do corpo de cordeiros, e suas proporcoes em relacao ao peso vivo (PV) e peso de corpo vazio (PCV). Utilizaram-se 22 cordeiros machos inteiros, filhos de carneiros Texel e ovelhas cruzas (Texel x Ideal). Desses, quatro foram abatidos ao nascimento, e os restantes ao desmame e aos 28 e 33kg. A determinacao do crescimento dos constituintes corporais foi realizada atraves de equacoes alometricas, utilizando-se o logaritmo do peso de cada componente corporal, em funcao do logaritmo do PCV. As proporcoes do trato gastrintestinal (TGI), do conjunto de orgaos internos (COI), da gordura interna (GOI) e da carcaca aumentaram com a elevacao do PV e PCV (P<0,05), enquanto que coracao, figado, rins, baco, (pulmao e traqueia), sangue, patas e pele diminuiram suas proporcoes (P<0,05). Os constituintes do corpo apresentaram diferentes ritmos de crescimento. Um grupo foi de desenvolvimento precoce (coracao, rins, pulmoes + traqueia, patas, sangue e cabeca), e outro tardio (rumen, reticulo, omaso e abomaso), TGI e GOI. Os restantes (figado, baco, intestinos, pele e carcaca) cresceram na mesma velocidade que o PCV.

Growth of lambs slaughtered at different weights: bone, muscle and fat of the carcass and its cuts

This experiment was developed at the Ovine Section of Animal Science Department, at Federal University of Santa Maria, Brazil- The purpose of this experiment was to determine the quantity of bone, muscle and fat of the carcass, and the growth ofbone and muscle of the carcass, and of the carcass cuts. Twenty-two intact mate lambs, sired by Texel males, from crossbreed Texel -Ideal dams were used. Four lambs were siaughtered at the beginning of the experiment (24 hours after birth) and groups of six lambs were siaughtered at weaning and when reaching 28 and 33kg. The lambs were kept in individual stalls together with their respective mothers until weaning (45 days of age). To study the growth of the carcass tissues and carcass cuts (hindquarter, shoulder, rib, backbone, neck), regression equations of the log of weight of each tissue, as a function of the log of empty body weight (EBW) or cold carcass weight (CCW) were fitted. The quantities of bone and muscle -increased (P 0.05) with the higher of the CCW, the proportion of fat increased from birth to weaning (P<0.05) and decreased after weaning (P<0.05). In relation to EBW and CCW, bones were early maturing (b=0.729188 and b=0.673340), followed by muscular tissue (b=1.075728 and b=1.001403). Among carcass cuts rib bone and muscle were later maturing than in other cuts.

Modificações na técnica de digestibilidade in vitro para avaliar forragens de baixa qualidade

Two experiments were undertaken at the Department of Animal Science at UFSM in arder to study in vitro digestibility technique modifications to assess low quality forages. Experiment I consisted of organic matter (OM) in vivo digestibility coefficients estimation, involving 10 tropical grass hay and two grain harvest straws. On Experiment II, one determined the in vitro digestibility coefficients through the TILLEY and TERRY technique (1963), MJ treatment - 48 hours of incubation with ruminal liquor (microbian fermentation) + 48 hours of pepsin incubation (enzymatic fermentation) and one studied the modifications over this technique named as M2 - incubation period delay (from 48h to 96h), with ruminal liquor renewal after 48h of incubation (new ruminal liquor addition over the solidphase of the samples, after centrifugation and liquid phase disregard); M3 - 96h of incubation with ruminal liquor with reinoculation after 48h of incubation (new liquor addition over the samples, without the centrifugation and liquid phase withdrawai); M4 - 96h of incubation with diluted ruminal liquor, with liquor renewal; M5 - 96h of incubation with diluted ruminal liquor with reinoculation; M6 - 96h of incubation with ruminal liquor, liquor renewal and pepsin incubation period delay (from 48 h to 72h) and M7 - 96h of incubation with ruminal liquor, reinoculation, digestion with 72h pepsin. A correlation analysis was undertaken between in vivo digestibility coefficient means and in vitro digestibility from the modifications to overall forages and a regression analysis over the treatment that presented high and significant correlations. From the results that were determined one could find that TILLEY and TERRY (1963) in vitro method does not present good precision to estimate low nutritional value forage digestibility and that among the tested modifications that one with 96h of fermentation with ruminal liquor (LR), with LR reinoculation after 48h of incubation + 48h with pepsin (M3) was the one that demonstrated to have the best efficiency to estimate the digestibility.