ABSTRACT The objective of this study was to investigate the multivariate relationship among body protein, fat, and macrominerals in Saanen goats of different sexes (castrated males, females, and intact males) using canonical correlation analysis. Individual records of 274 Saanen goats combined from 10 studies was used. Two sets of body constituents were established: the first one contained variables related to body protein or fat (canonical variate U) and the second contained variables related to body calcium, phosphorus, magnesium, sodium, or potassium (canonical variate V). Two canonical pairs were identified for each sex. However, irrespective of sex, first canonical pairs accounted for more than 87% of variance of the dependent variables, these only being used for the analysis. For canonical variate U1, canonical weights for protein were greater than that for fat (in castrated males, protein = 0.62 and fat = 0.41; in females, protein = 0.96 and fat = 0.039; and in intact males, protein = 0.81 and fat = 0.20). For canonical variate V1, in males, the highest canonical weights were for potassium and phosphorus, whereas the lowest were for calcium (in castrated males, potassium = 0.485 > phosphorus = 0.259 > magnesium = 0.206 > sodium = 0.129 > calcium = 0.081, and in intact males, potassium = 0.499 > phosphorus = 0.459 > sodium = 0.105 > magnesium = 0.024 > calcium = 0.001). On the other hand, in females, the highest canonical weights were for potassium and calcium, whereas the lowest was for magnesium (potassium = 0.539 > calcium = 0.201 > phosphorus = 0.178 > sodium = 0.088 > magnesium = 0.081). The current results may help to understand the role of sex on strength and nature of the association among body protein, fat, and macrominerals in growing Saanen goats.

ABSTRACT If the world population continues to increase exponentially, wealth and education inequalities might become more pronounced in the developing world. Thus, offering affordable, high-quality protein food to people will become more important and daunting than ever. Past and future challenges will increasingly demand quicker and more innovative and efficient solutions. Animal scientists around the globe currently face many challenging issues: from ensuring food security to prevent excess of nutrient intake by humans, from animal welfare to working with genetic-engineered animals, from carbon footprint to water footprint, and from improved animal nutrition to altering the rumen microbiome. Many of these issues are most likely to continue (or to exacerbate further) in the coming years, but animal scientists have many options to surmount the obstacles posed to the livestock industry through tools that are presently available. The frequency, interval, and intensity of livestock impacts, however, differ across regions, production systems, and among livestock species. These differences are such that the generalization of these issues is impossible and dangerous. For instance, when we discuss domesticated ruminant nutrition in the human food context, we look for the most efficient ruminant feeds that complement, rather than compete with, grains grown for direct human nutrition. Greater scrutiny and standardization are needed when developing and validating methodologies to assess short- and long-term impacts of livestock production. Failure in correctly quantifying these impacts may lead to disregard and disbelief by the livestock industry, increased public confusion, and the development of illusionary solutions that may amplify the impacts, thereby invalidating its original intent.

The objective of this study was to determine the protein requirements for the growth of intact male, female, and castrated male Saanen goats weighing 30 to 45 kg of body weight (BW) and to compare estimates of the protein requirements for maintenance (NPm) by the comparative slaughter and nitrogen balance techniques. To determine the maintenance requirements, 55 goats were assigned in a split-plot design using a 3 × 3 factorial arrangement (three sexes and three dry matter intake (DMI) levels). A linear regression of retained N (as measured by the slaughter technique and estimated from the nitrogen balance) on N intake on a daily basis was used to calculate the net protein for maintenance. The net protein requirement for weight gain (NPg) was obtained using 65 goats fed ad libitum in a completely randomized design. The first derivative of the allometric equation of protein content in the empty BW with respect to the empty BW yielded estimates of the NPg. According to the comparative slaughter technique, the estimated NPm was 1.46 g/kg of metabolic weight, which is 50% lower than the estimate from the nitrogen balance technique. When evaluating the variance of the error, the nitrogen balance also showed greater values, indicating less precision compared with that of the comparative slaughter technique. The daily NPg ranged from 155.7±10.9 to 153.4±13.5 g/kg of EBW gain for growing Saanen goats. The protein requirements (NPm and NPg) of intact male, female, and castrated male Saanen goats are similar, from 30 to 45 kg BW, in accordance with current feeding systems. Moreover, the results of the present study indicate that the estimate of NPm using the comparative slaughter technique is more precise and lower than that using the N balance technique.

The objective of this investigation was to evaluate the weight and percentage of the non-carcass components and the mineral content (macro minerals and trace minerals), crude protein, ether extract, moisture and vitamin E of the heart, liver, tongue, lungs, reticulum, kidneys and meat from the longissimus dorsi of lambs in feedlot finishing. Thirty-two non-castrated Ile de France male lambs, fed diets containing sunflower seeds and vitamin E from 15 to 32 kg of body weight were allotted in a completely randomized design in a 2 × 2 factorial arrangement. The weight of the gastrointestinal tract was higher in the lambs fed diets containing vitamin E (10%). No difference was observed in the liver as to the mineral matter, crude protein, ether extract, moisture (2.01; 20.03; 2.39 and 74.78 g/100 g, respectively), the macro minerals and trace minerals, except iron. In the tongue, lungs, reticulum, kidneys and meat there was no in fluence of diets in the studied variables. The liver and the meat presented different values of crude protein (20.01 and 18.34 g/100 g, respectively), and the heart (1.03 mg/100 g) showed a higher content of vitamin E. High contents of manganese, zinc and copper were observed in the liver. The evaluated non-carcass components were nutritionally equal to the sheep meat, once, in addition to their high yield in relation to the body weight at slaughter, the non-carcass components are sources of nutrients.

Performance, carcass, non-carcass and commercial cuts and components of Texel × Santa Inês crossbred lambs, managed in confinement and fed diets based on soybean oil, soybeans and a conventional diet, with or without the use of monensin (78 ppm dry matter basis) were evaluated. Thirty-six Texel × Santa Inês lambs (18 males and 18 females) were managed in intensive systems. Animals were slaughtered after 87 days of confinement, and performance, carcass characteristics, weight and percentages of carcass and non-carcass components were evaluated. The animals fed the control diet had heavier carcass and parts than animals fed soybean, while the oil diet did not differ from the controls in most parameters. The animals fed soybean showed lower intake kg dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and metabolizable energy (ME) compared with animals fed the control diet, increased ether extract (EE) intake in kg, % body weight (BW) and metabolic weight (MW) and did not differ from the soybean oil diet. Animals receiving monensin had lower DM intake, OM, CP, EE, NDF, gross energy (GE) regardless of the expression, % kg BW, or % PM, than the animals that did not receive the additive. Males produced better and had heavier cuts than the females; the latter deposited subcutaneous fat earlier. Animals that received oil or soybean showed greater body weight and small intestine percentage. Soybean oil intake did not improve performance, carcass weights or parts of Santa Ines × Texel lambs in confinement. Soybeans at 15% dry matter reduced energy intake and lamb performance. The use of monensin at 78 ppm on a dry matter basis is not recommended for lambs in confinement, especially if associated with oil or soybeans that may harm animal performance.

Objetivou-se determinar a influência da proporção volumoso e da fonte de gordura da dieta sobre as características de carcaça e os cortes comerciais de cordeiros. Utilizaram-se 24 cordeiros Santa Inês machos não-castrados, recebendo, à vontade, dieta com duas proporções de volumoso (30 e 70%) e de gordura (sem gordura, gordura protegida e grão de soja) e abatidos com peso corporal médio de 35,4 kg (± 1,5 kg). Os animais alimentados com dietas com 30% de volumoso apresentaram os maiores pesos e rendimentos de carcaça. As porcentagens de braço posterior e pernil foram maiores nos animais que receberam a dieta com 30% de volumoso sem adição de fonte de gordura. O comprimento total de perna e o comprimento interno foram maiores nos animais que receberam a dieta com 70% de volumoso, enquanto a largura de perna foi maior naqueles alimentados com a dieta com 30% de volumoso. A adição de fonte de gordura em dietas com alta porcentagem de concentrado pode aumentar os rendimentos de carcaça. Esse efeito é maior quando utilizada gordura protegida em relação ao grão de soja integral. Apesar de as dietas não terem efeito na maioria dos cortes, o efeito sobre o pernil confirma a influência da dieta sobre esse corte nobre.

This work aimed at determining the influence of roughage proportions and fat source of the diet on characteristics of carcass and comercial cuts of lambs. It was used 24 non-castrated Santa Inês male lambs, ad libitum fed diet with two proportions of roughage (30 and 70%) and fat (no fat, protected fat, and soybean) slaughtered at an avarage body weight of 35.4 kg (± 1.5 kg). Animals fed 30% roughage diet showed the highest weights and carcass yields. The percentages of posterior arm and ham were higher in animals fed 30% roughage with no addition of fat source. Total leg length and internal length were higher in animals fed 70% roughage diet while leg width was higher for those fed 30% roughage diet. Addition of fat source in diets with high percentage of concentrate can increase carcass yields. This effect is higher when protected fat is used regarded to whole soybean. Although diets do not have effect on most of these cuts, the effect on the ham confirms the influence of the diet on this noble cuts.

Avaliaram-se o desempenho e as características de carcaça de 36 cordeiros machos não-castrados, Santa Inês puros e mestiços Dorper × Santa Inês e Texel × Santa Inês, manejados em três sistemas (intensivo semi-intensivo e extensivo) e abatidos com peso médio de 38,41 ± 1,24 kg. Os melhores ganhos de peso foram observados nos cordeiros criados em sistema intensivo, que apresentaram também os maiores pesos e rendimentos de carcaça. Poucas influências foram constatadas sobre as medidas de carcaça e dos cortes comerciais, sobretudo para maiores pesos nos cortes provenientes do manejo intensivo, proporcionado pelo maior peso da carcaça. O percentual relativo dos cortes em relação à carcaça fria praticamente não variou entre os sistemas. O sistema intensivo proporcionou melhor desempenho, independentemente do grupo genético. A utilização das raças Texel e Dorper em cruzamento com Santa Inês eleva o rendimento das carcaças.

It was evaluated the performance and the carcass characteristics of 36 non-castrated male lambs, Santa Inês purebreed and crossbreeds from Dorper × Santa Inês and Texel × Santa Inês, managed in three different systems (intensive, semi-intensive and extensive), slaughtered at 38.41 ± 1.24 kg. It was observed the highest weight gain for lambs reared in intensive system, which also showed the greatest carcass yield. The management systems did not influence carcass measures of animals in intensive system much because of the greater weight of the carcass. The intensive system provided the best performance, regardless the genetic group. The use of Texel and Dorper breeds in crossings with Santa Inês increases carcass yield.