ABSTRACT This study aimed to evaluate the effects of sunflower meal (SFM) inclusion on the performance, nutrient digestibility, and respirometric parameters in sheep. Twenty-four Dorper × Santa Inês uncastrated males, with an average age of 5 mo and initial body weight (BW) of 27.91±6.0 kg, were distributed in a randomized block design with four treatment diets containing 0, 100, 200, and 300 g of SFM/kg of total dry matter, replacing soybean meal. Intake, weight gain, ingestive behavior, and in vitro digestibility were evaluated according to the SFM inclusion. The respirometric parameters were evaluated in an open-circuit respirometric chamber. There was a quadratic response in dry matter intake expressed according to the SFM inclusion, with minimum points of 90.56 g/kg 0.75 BW for inclusion levels of 96 g of SFM/kg. A linear decrease in the in vivo digestibility of dry matter, neutral detergent fiber, and non-fibrous carbohydrate and in vitro fermentation of dry matter and fibrous carbohydrates was observed in response to SFM inclusion. These results reflect the higher fiber content of the byproduct, which reduced the non-fibrous carbohydrates in the diets. Despite the change in nutrient availability, average daily gain (299 g/day), O 2 consumption (26.24 L/kg 0.75 BW), and CH 4 production (2.25 L/kg 0.75 BW) were not influenced by the SFM inclusion, indicating that changes in the nutritional value of the diet did not affect the animals’ energetic metabolism. Sunflower meal inclusion decreased the digestibility but did not affect the animal gain and the respirometric parameters. The SFM can replace soybean meal in the diet of growing lambs; however, it has a maximum inclusion point of 88 g SFM/kg for feed conversion, which is a necessary factor for evaluating the replacement cost.

Resumo: O objetivo deste trabalho foi avaliar a eficiência da roscovitina na inibição reversível de oócitos de ovelhas pré-púberes, no estádio de vesícula germinativa (VG), e investigar a cinética da progressão da meiose após a remoção do inibidor. Complexos cumulus-oócito, recuperados de cordeiras da raça Sarda com 30-40 dias, foram cultivados por 6 horas em meio de maturação (controle) contendo 75 μmol L-1 de roscovitina (Rosco) a 38,5°C e 5% de CO2. Em seguida, os complexos foram submetidos à maturação in vitro (MIV) por 18 ou 23 horas, em meio isento de inibidor, suplementado com gonadotrofinas. A avaliação da configuração nuclear em coloração Hoescht, sob microscópio invertido de fluorescência, revelou que 88,7% dos oócitos tratados permaneceram no estágio VG, conforme observado para os imaturos (97,3%) corados após a coleta. Essa inibição foi reversível; contudo, a proporção de oócitos (83,3%) em metáfase-II, após 23 horas de MIV, foi significativamente maior do que a observada após 18 horas (29,5%), em que a meiose ainda estava em progressão com 34,2% de oócitos em metáfase-I, 11,6% de oócitos em anáfase-I e 18,5% de oócitos em telófase-I. A roscovitina é eficiente no bloqueio da maturação nuclear em oócitos de ovelhas pré-púberes; no entanto, apesar da reversibilidade, a progressão da meiose é retardada e requer mais tempo para ser concluída.

Abstract: The objective of this work was to evaluate the efficiency of roscovitine on reversibly inhibiting oocytes from prepubertal sheep at the germinal vesicle (GV) stage, and to investigate the kinetics of meiosis progression after inhibitor removal. Cumulus-oocyte complexes, recovered from Sarda breed lambs aged 30-40 days, were cultured for 6 hours in a maturation medium (control) containing 75 μmol L-1 roscovitine (Rosco) at 38.5°C and 5% CO2. Then, the complexes were subjected to in vitro maturation (IVM) for 18 or 23 hours, in an inhibitor-free medium supplemented with gonadotropins. The evaluation of nuclear configuration by Hoescht staining, under a fluorescence-inverted microscope, showed that 88.7% of the lamb oocytes treated with roscovitine remained at the GV stage, as observed for the immature ones (97.3%) stained after collection. The inhibitory action was reversible; however, the proportion of oocytes (83.3%) at the metaphase-II stage, after 23 hours of IVM, was significantly higher than that observed after 18 hours (29.5%), in which meiosis was still in progression with 34.2% oocytes at metaphase-I, 11.6% oocytes at anaphase-I, and 18.5% oocytes at telophase-I. Roscovitine is efficient to arrest the nuclear maturation in oocytes from prepubertal sheep; however, despite the reversibility, meiosis progression is delayed, requiring more time to be completed.

ABSTRACT. The objective of this work was to evaluate the performance, body morphometric measurements and testicular development in lambs fed with different rates of sunflower meal inclusion. The animals (24) were randomly distributed in treatments with 0, 10, 20 and 30% of sunflower meal in the dry matter of the diet, in six replicates, during 56 days of confinement. The addition of the coproduct at increasing dietary rates increased linearly the dry matter intake in the percentage of live weight and neutral detergent fiber. Despite this, there was a linear reduction in ether extract intake and chest width. On the other hand, there was no difference in daily, total and final weight gains. The body condition score; height of withers, croup and thorax; length of body and croup; width of fore croup, hind croup and chest; thoracic and neck diameters also did not change with the addition of the coproduct. The testicular measures 26.76; 6.11; 6.08; 5.22; 5.21; 4.80, and 4.81cm varied quadratically with the inclusion. Therefore, the inclusion of 30% of the coproduct changes nutrient intake and testicular biometry, but does not interfere in the body weight and development, being an economical alternative.