ABSTRACT The objective of this study was to evaluate the effect of replacing ground corn (402 g kg−1 of dry matter) with rehydrated corn grain silage (RCGS; 425 g kg−1 of dry matter) in a flushing diet on follicular development in tropical Santa Inês ewes. Fifteen ewes were randomly assigned to one of two treatment groups: a diet with ground corn (control, n = 7) or a diet with RCGS (n = 8). The first day of the diets was designated d0, and the diets were fed for 30 days, up to two days after the end of the estrus synchronization protocol. The estrus synchronization protocol (intravaginal progestogen sponge for 11 days plus 300 IU eCG and 37.5 µg d-cloprostenol IM two days before sponge removal) started on d17 of the diets. The number and diameters of ovarian follicles ≥3 mm were assessed by ultrasound on the day before the diets were provided (d−1), on d14, and then daily from two days before sponge removal until ovulation or up to the eighth day after sponge removal. Blood samples were collected on days −1, 0, 6, 12, 18, 24, and 30 for glucose and urea analyses. There was no effect of the treatments on dry matter intake, plasma glucose, and urea nitrogen concentrations, or on the percentage of ewes that ovulated and on the number of ovulations. The number of follicles ≥3 mm did not differ between treatment groups; the number increased between d−1 and d14 and did not differ between d14 and d28. The diameter of ovulatory follicles at sponge removal, the interval from sponge removal to estrus, and the growth rate of the ovulatory follicles were greater in the RCGS group than in the control group, resulting in larger follicles at ovulation. Replacement of ground corn by RCGS in the flushing diet does not increase the number of ovulations but results in delayed onset of estrus and ovulation of larger follicles.

ABSTRACT The objective of this study was to evaluate residual feed intake (RFI), residual intake and body weight gain (RIG) and their relationship with other traits of efficiency, performance, and economic analysis of sheep. Lambs (n = 102) were evaluated during 56 days and a herd consisting of 500 ewes was simulated with the mean of dry matter intake (DMI) and final body weight of the lambs, the same as that of the experimental lambs. The lambs were fed hay-based diet of Tifton 85 (Cynodon spp.), corn, and soybean in the voluminous:concentrate ratio of 35:65. Residual feed intake and RIG were correlated with DMI, feed conversion ratio, and feed efficiency. Residual intake and body weight gain were positively correlated with average daily gain, relative growth rate, and Kleiber's rate. The most efficient production systems (lower RFI and higher RIG) had lower costs and higher profit margins. The net present value (NPV) and internal rate of return (IRR) were higher in systems with more efficient lambs. In systems with less efficient lambs, NPV and IRR were negative and lower, respectively. Efficient animals for RFI and RIG showed satisfactory performance and better economic results.

ABSTRACT The objective of this study was to examine the effects of suckling schemes (continued, controlled, and total separation) and the type of pregnancy on performance and serum cortisol concentration in lambs. A total of 29 Santa Inês ewes and 40 lambs were used, and the randomized block design was applied in a split-plot scheme with a 3 × 2 factorial arrangement in the plot and time in the subplot. For controlled suckling, the diet was supplied twice daily during one hour, starting on their 10th day of life. Total and average daily intakes of concentrate dry matter of lambs that underwent total separation was higher than those of lambs under continued suckling. Lambs subjected to total separation demonstrated higher concentrate dry matter intake/weight gain ratio, lower total weight gain, lower average daily weight gain, and lower weaning weight than those subjected to continued and controlled suckling. Lambs from single pregnancy demonstrated higher weight gain and obtained higher weight at weaning. Lambs subjected to total separation have a developmental delay. However, the lower performance of lambs subject to total separation cannot be attributed to stress because there is a decrease in the serum cortisol concentration over time.

Machos e fêmeas, Santa Inês puros (SI) e cruzados de matrizes Santa Inês com reprodutores das raças Texel (TxSI), Ile de France (IFxSI) e Bergamácia (BxSI), terminados em confinamento e abatidos aos 15, 25, 35 e 45kg de peso vivo. Após o abate, foram tomados os pesos das vísceras e analisado o crescimento alométrico. O pulmão dos machos BxSI cresceu em taxas mais elevadas que SI e TxSI. A tráqueia/esôfago dos machos SI e TxSI cresceu mais lentamente que dos IFxSI e BxSI. Os rins dos machos BxSI cresceram mais rápido comparado aos dos TxSI e IFxSI. O fígado das fêmeas TxSI cresceu em taxas mais elevadas quando comparadas às fêmeas dos outros grupos genéticos. Os machos e fêmeas do grupo TxSI apresentaram taxas de crescimento maiores para rúmen/retículo, respectivamente, comparado aos grupos SI e BxSI.

Males and females, including purebred Santa Inês lamb (SI) and crosses between Santa Inês dams and Texel (TxSI), Ile de France (IFxSI) and Bergamasca (BxSI) sires were feedlot finished and slaughtered at 15, 25, 35 and 45kg live weight. After slaughter, the following non- carcass components were weighed and calculated the allometric growth. Lungs of BxSI males grew faster than those of SI and TxSI. Trachea/esophagus in SI and TxSI males grew slower than IFxSI and BxSI. Kidneys BxSI males grew faster than TxSI and IFxSI. Livers of female TxSI lamb grew more rapidly than those of females in the other genetic groups. In both males and females, the rumen/reticulum grew faster in the TxSI group than SI and BxSI groups.

Data from 2439 goats of the Saanen, Alpine, Anglo Nubian and Toggenburg breeds recorded from 1976 to 2009 by the Association of Goats and Sheep Breeders of Minas Gerais were used in principal component analysis. After consistency of data, six morphological variables (thorax perimeter, body length, withers height, height, width and length of the rump) and 12 variables related to breed standard score and fitness (breed characteristic, head, palette and topline, feet and legs, dairy type, body capacity, udder, rear and front ligament, udder texture, teat and final score) were analyzed. Based on the magnitude of the eigenvalue (lower than 0.7), eleven variables considered redundant were discarded, resulting in reduced costs of technician labor to evaluate the animals. Maintenance of records on height, length, rump width, breed characteristic, dairy type, front ligament and udder texture is recommended.

The effects of overfeeding with protein of different degradability on body condition, plasma urea nitrogen and progesterone concentrations, ovulation number and follicular dynamics were assessed in Santa Ines ewes. Twelve ewes were assigned to a randomized block design according to body weight and received overfeeding with soybean meal or with corn gluten meal or maintenance diet for 28 days before ovulation and during the next estrous cycle. Blood samples were taken on days 7, 14, 21, and 28 after the beginning of treatments for analysis of plasma urea nitrogen and on days 3, 6, 9, 12, and 15 into the estrous cycle for analysis of plasma urea nitrogen and progesterone. Follicular dynamics was monitored daily by ultrasound during one estrous cycle. Dry matter and crude protein intake, weight gain, plasma urea nitrogen concentration before ovulation, number of ovulations, diameter of the largest follicle of the 1st and of the 2nd waves and the growth rate of the largest follicle of the 1st wave were higher in the ewes that received overfeeding. The growth rate of the largest follicle of the 3rd wave was higher in the ewes fed maintenance diet. The back fat thickness, plasma urea nitrogen before ovulation and progesterone concentrations, diameter of the largest follicle of the 2nd wave and growth rate of the largest follicle of the 3rd wave were higher in ewes that received overfeeding with soybean meal. The growth rate of the largest follicle of the 1st wave was higher in ewes that received overfeeding with corn gluten meal. Overfeeding with protein-rich feeds may increase the ovulation number and with soybean meal, it may be effective in increasing plasma progesterone concentration in ewes.

This experiment evaluated the effect of adding macaúba (Acrocomia aculeata) cake replacing corn on body measurements and carcass characteristics of Santa Inês lambs. Twenty four 5-month-old uncastrated male lambs were tested using a randomized blocks design. Lambs were distributed into four experimental groups, receiving diets with 0, 100, 200 and 300 g/kg of macaúba cake. After 60 days in feedlot, measurements of body length, thoracic perimeter, height at the anterior and rump height were taken. The lambs were slaughtered, skinned and eviscerated. Carcass were weighed hot and chilled at 2 ºC during 24 h. Cooling losses, hot carcass weight, cold carcass weight, hot carcass yield, cold carcass yield, half carcass weight, fat thickness, final weight, slaughter weight, empty body weight, thorax depth, croup width, perimeter of the croup, carcass length, internal carcass length, hindlimb length, hindlimb width and hindlimb conformation score were evaluated. Only hindlimb width was inversely correlated to adding macaúba cake in the diet. Macaúba cake can be included in diets for lamb in feedlot up to 300 g/kg without affecting body measurements in vivo or carcass characteristics.

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.

This experiment aimed to determine the influence of diets with inclusion of protected fat and vitamin E on performance, yield and carcass characteristics of feedlot lambs with different weights. Thirty-two non-castrated Santa Ines lambs were fed diets with a ratio of 40% forage and 60% concentrate ad libitum, with presence or absence of protected fat and/or vitamin E, in a total of four diets. Two weights of early containment were also considered: between 20 and 25 kg and between 30 and 35 kg. All animals were slaughtered at 84 days of confinement. Animals fed diets without addition of protected fat, regardless of the use of vitamin E, had the highest intakes of dry matter, crude protein, neutral detergent fiber and ash, and decreased intake of ether extract. The variables investigated did not affect daily weight gain and total gain. Feed conversion was better for the lighter confined animals not fed protected fat. The heavier feedlot lambs fed diets with vitamin E showed higher cold carcass. The warm carcass for the lighter animals confined fed with vitamin E, and the heavier ones, fed with protected fat and vitamin E, showed the best yields of cold carcass. Objective measures of the carcass cold had the highest mean for heavier feedlot lambs. The addition of fat in the diet reduces the intake of dry matter and increases the ether extract. Although the inclusion of vitamin has no effect on intake of nutrients, it protects the carcasses from losses during cooling, and weight differences at containment directly reflect the measures of the carcasses.

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.

Utilizaram-se 103 cordeiros, machos e fêmeas, Santa Inês puros (SS) e mestiços com Texel (TS), Ile de France (FS) e Bergamácia (BS) confinados individualmente e abatidos aos 15, 25, 35 ou 45 kg de peso vivo. Após abate e resfriamento da carcaça, foram separados os cortes comerciais pescoço, costela/fralda, costeleta, lombo, paleta e perna, os quais foram dissecados em músculo, osso e gordura. O crescimento alométrico de cada tecido da meia-carcaça foi avaliado em relação ao peso da carcaça fria e os tecidos da perna, do lombo e da paleta em relação ao peso do corte. O desenvolvimento do músculo na meia-carcaça nos machos Santa Inês, Santa Inês × Texel e Santa Inês × Ile de France e nas fêmeas Santa Inês e Santa Inês × Texel foi semelhante ao do peso vivo vazio (coeficiente alométrico (b) = 1), enquanto, nos machos Bergamácia e nas fêmeas Ile de France e Bergamácia, foi precoce (b<1). O desenvolvimento do músculo foi precoce (b<1) na paleta dos machos TS e BS e das fêmeas FS e BS; no lombo de machos TS e fêmeas SS, TS e BS; e na perna dos machos BS e fêmeas TS e BS. O desenvolvimento do osso nos cortes e na meia-carcaça foi precoce (b<1) em todos os grupos, com exceção dos ossos da paleta dos machos SS, TS e BS e das fêmeas TS; e dos ossos da perna dos machos BS, com desenvolvimento semelhante (b=1) ao desenvolvimento do corte. O desenvolvimento da gordura nos cortes e na meia-carcaça foi tardio (b>1) em todos os grupos, com exceção da gordura da paleta nos machos BS, cujo desenvolvimento foi semelhante ao do corte (b=1).

This study was conducted using 103 male and female lambs from the following genetic groups: Santa Inês (SS) purebred and Santa Inês × Texel (TS), Santa Inês × Ile de France (FS), and Santa Inês × Bergamacia (BS) crossbred. The animals were slaughtered at the following body weights: 15, 25, 35 or 45 kg. After slaughter and cooling of the carcasses, the following cuts were made: neck, rib/flank, short ribs, loin, blade, and hind limb. The composition in muscle, bone and fat of cuts and ½ carcass were evaluated. The alometric growth of each tissue of the loin, shoulder and leg in relation to the cut weight, and of each tissue of the ½ carcass in relation to the cold carcass weight, was measured. The allometric growth of muscles in the ½ carcass, for BS males and FS and BS females, was early (b<1). The alometric growth of the bone in the cuts and ½ carcass was early (b<1), except for shoulder bone in SS, TS and BS males, and TS females; and leg bone in BS males, with isogonic allometric growth (b=1). The development of fat in the cuts, and ½ carcass was late (b>1), except shoulder fat in BS males, with isogonic growth (b=1). The growth rate of shoulder muscles in SS and FS males, SS and TS females was isogonic (b=1); for TS and BS males, FS and BS females, it was early (b<1). The muscle development in the loin from SS, FS and BS males, and females FS, was isogonic (b=1); for TS males and SS, TS and BS females, it was negative heterogonic (b<1). The allometric growth of the muscle in the loin from SS, TS and FS, and SS and TS females, was isogonic (b=1); and for BS males and TS and BS females, it was negative heterogonic (b<1).

Cento e três cordeiros, machos e fêmeas, Santa Inês puros (SS) e cruzas com Texel (TS), Ile de France (FS) e Bergamácia (BS) foram utilizados no estudo do crescimento alométrico dos cortes. Os animais foram confinados em gaiolas individuais e abatidos aos 15, 25, 35 e 45 kg de PV. Após abate e resfriamento da carcaça, foram feitos os cortes: pescoço, costela/fralda, costeleta, lombo, paleta e perna, sendo esses dois últimos sem os braços, para avaliação do crescimento alométrico individual em relação ao corpo vazio (PCVZ). O crescimento alométrico do pescoço foi isogônico em todos os grupos, à exceção do grupo Santa Inês x Bergamácia (crescimento heterogônico positivo), comprovando que esse corte cresce de forma semelhante ao PCVZ. Os machos TS e FS apresentaram ritmo de crescimento do pescoço menor que o dos machos BS. A costela/fralda, em todos os grupos, teve crescimento lento entre os pesos avaliados, observando-se que, nos grupos TS e FS o ritmo de crescimento foi maior que no grupo SS. Nos machos, o desenvolvimento da paleta foi semelhante ao PCVZ, enquanto, nas fêmeas, foi lento em relação ao PCVZ. O desenvolvimento da costeleta e do lombo foi lento em todos os grupos, à exceção das fêmeas FS, nas quais acompanhou o PCVZ; os coeficientes alométricos de costeleta nesses animais foram menores que nos demais outros grupos. O desenvolvimento da perna foi similar ao PCVZ nos machos SS, TS e FS e nas fêmeas FS, porém, foi menos intenso nos machos BS e nas fêmeas SS, TS e BS.

This study was conducted using 103 male and female lambs from the following genetic groups: purebred Santa Inês (SS) and crossbreds of Santa Inês x Texel (TS), Santa Inês x Ile de France (FS), and Santa Inês x Bergamacia (BS). Animals were slaughtered at one of the following body weights: 15, 25, 35 or 45 kg. After slaughter and cooling of the carcasses, the following cuts were made: neck, rib/flank, short ribs, loin, blade, and hindlimb. The alometric growth of each cut in relation to the empty body weight (EBW) was measured. The alometric growth of the neck was isogonic (b=1) for most genetic groups and accompanied EBW growth. However, for BS lambs the growth was heterogonic (b>1) or slow growth. TS and FS male lambs showed slower neck growth rate compared to the BS lambs. The rib/flank had slow growth for all groups but TS and FS lambs showed greater growth rate than the SS animals. For males, the blade development followed the EBW while females had a slower growth rate. The development of short ribs and loin was slow for all groups, except on FS female lambs, in which both short ribs and loin growth followed that of EBW; the alometric coefficients obtained for short ribs were lower on FS female lambs compared to those of the remaining genetic groups. The development of hindlimb accompanied the EBW for SS, TS and FS males and also for FS female lambs.

O trabalho foi desenvolvido com o objetivo de estudar o efeito do sexo dos animais, do grupo genético e do peso de abate no desempenho de animais confinados. Foram utilizados 103 cordeiros, machos e fêmeas, Santa Inês puros (SS) e cruzas Santa Inês com Texel (TS), Ile de France (FS) e Bergamácia (BS), confinados em gaiolas individuais. Mediram-se a dieta fornecida e as sobras diárias, para cálculo do consumo de matéria seca (MS), energia metabolizável (EM), proteína digestível (PD) e fibra em detergente neutro (FDN). Os cordeiros foram abatidos em quatro pesos: 15, 25, 35 e 45 kg de peso vivo. Avaliaram-se o ganho de peso diário (GPD), o número de dias no confinamento (ND), a conversão alimentar (CA) e o consumo de MS, PD, EM e FDN, nas três fases de crescimento: 15 a 25 kg (1), 25 a 35 kg (2) e 35 a 45 kg (3). Também foram avaliados as idades de abate (IA), o peso do corpo vazio (PCVZ) e rendimento de carcaça (RC). Aos 35 e 45 kg, os cordeiros TS e FS apresentaram IA inferiores e as cordeiras SS, IA superiores. O ND dos cordeiros BS de 35 a 45 kg foi maior que dos TS. Aos 35 e 45 kg, o PCVZ dos cordeiros TS e FS foram menores. Os melhores GPD foram dos cordeiros TS, seguidos do FS e SS. Os consumos de MS, PD, EM e FDN foram semelhantes entre os grupos genéticos, nas fases 1 e 2 de crescimento. Verificou-se que os cordeiros TS tenderam a aumentar o consumo, com o incremento de peso, enquanto os outros grupos tenderam a diminuir. A CA elevou-se com o aumento de peso, com exceção dos machos FS. Os machos não apresentaram diferenças na CA entre os grupos genéticos, entretanto, as fêmeas TS e FS apresentaram valores melhores. Aos 35 e 45 kg, as fêmeas apresentaram maiores RC que os machos. Aos 35 kg, os melhores RC foram dos machos TS.

The work was carried out to evaluate the effect of animal sex, genetic group and slaugher weight on fedlot lambs performance. One hundred and three male and female lambs, purebred Santa Inês (SS) and crosses between Santa Inês and Texel (TS), Ile de France (FS) and Bergamacia (BS) were fedlot in individual cages. Diet and orts were daily collected to calculate the intakes of dry matter (MS), metabolizable energy (EM), digestible protein (PD) and neutral fiber detergent (FDN). The lambs were slaughtered at four weights: 15, 25, 35 and 45 kg of live weight. Weight gain (GPD), number of days in confinement (ND), feed:gain ratio (CA) and intakes of MS, PD, EM and FD were analyzed during three growing phases: 15 to 25 kg (1), 25 to 35 kg (2) and 35 to 45 kg (3), for each genetic group and each sex. The slaughter age (IA) and the empty body weight (PCVZ) were also analyzed. At high weights, TS and FS male lambs showed inferior IA, and the female lambs, superior IA. ND of BS lambs from 35 to 45 kg was superior than TS lambs. From 35 to 45 kg, PCVZ of TS and FS lambs was inferior. The best GPD was observed for TS lambs, followed by FS and SS. The intakes of MS, PD, EM and FDN were similar among the genetic groups, during the phases 1 and 2. TS lambs intake tended to increase as body weight increased, whereas the other groups showed tended to decrease. CA increased as slaughter weight increased. The males did not show differences in CA among the genetic groups, but TS and FS females showed better results. At 35 and 45 kg, the females showed superior RC than the males. At 35 kg, the TS males showed better RC than the other groups.

Objetivou-se avaliar a composição centesimal da carne de cordeiros da raça Santa Inês (SI x SI) e de seus mestiços com Texel (T x SI), abatidos com diferentes pesos vivos. O músculo biceps femoris foi utilizado para as análises de umidade, de proteína bruta (PB), de extrato etéreo (EE) e de cinzas. O delineamento foi inteiramente casualizado, com 16 tratamentos, em esquema fatorial 2x2x4, com dois grupos genéticos, dois sexos (14 machos e 13 fêmeas em cada grupo) e quatro pesos de abate (15, 25, 35 e 45 kg PV), sendo os dados analisados com auxílio Proc GLM do programa estatístico SAS. A umidade diminuiu com o peso de abate, variando de 76,09 a 74,31%, e os machos apresentaram valores maiores em relação às fêmeas. A PB teve comportamento quadrático, variando de 20,27 a 21,36%. Com o aumento do peso de abate, o teor de EE elevou, variando de 0,95 a 3,78%, sendo que SI x SI tiveram maior teor de EE. Os machos, de ambos os grupamentos genéticos, tiveram menor teor de extrato etéreo. Houve declínio do teor de cinzas com o avanço do peso, e as fêmeas apresentaram os maiores valores. Conclui-se que o peso de abate alterou a composição centesimal da carne de cordeiros, de modo que os animais mais pesados apresentaram menor teor de umidade e de cinzas e maior teor de EE. O sexo e o grupo genético influenciaram o teor de EE, indicando a possibilidade de abate em pesos diferentes, conforme o sexo e a raça.

The objective of this study was to evaluate the meat centesimal composition of Santa Ines pure breed and Santa Ines vs Texel crossbreed lambs, slaughtered at different body weights. Thirteen males and fourteen females from both breeds were selected. The muscle biceps femoris was used to determine water, crude protein, crude extract and minerals contents. The experiment was arranged randomly, with 16 traits in a 2x2x4 factorial scheme with two genetic groups, two genders (14 males and 13 females in each group) and four slaughter weights (15, 25, 35 e 45 kg of body weight). Data was analyzed by Proc GLM of SAS program. It was observed that the water content decreased as the slaughter weight increased, ranging from 76.09 to 74.31%. The males had higher water content values when compared to the females. The crude protein showed a quadratic behaviour, ranging from 20.27 to 21.36%. As the slaughter weight increased, the value of crude extract content also increased, ranging from 0.95 to 3.78%. The SIxSI animals presented higher ether extract content. In both genetic groups, the males presented lower ether extract content. The minerals content decreased as the slaughter weight increased and the females presented higher values when compared to the males. It was concluded that, as slaughter weight increased, the ether extract content also increased, while water and minerals content decreased and the crude protein content showed a linear decrease. The meat of female lambs presented higher contents of ether extract and less water content when compared to the meat of male lambs. The SIxSI lambs presented higher ether extract content when compared to TxSI lambs.