ABSTRACT The objective of this study was to evaluate the effect of the seasons (Summer and Autumn), on live weight, body condition, mass motility, percentage of live spermatozoa, and sperm-cell concentration of Creole roosters (Gallus domesticus) from Mexico. Semen from 35-week-old Creole roosters was collected weekly during 10 weeks in Summer and Autumn, through the dorso-abdominal massage technique. Roosters were individually kept under a constant photoperiod (16 hours light:8 hours dark). The average live weight was 4.5% higher (p<0.05) in Autumn (2.78 kg) than in Summer (2.66 kg), therefore this variable increased with age (r = 0.85, p<0.05). Category 2 of body condition occurred (p<0.05) with higher probability than the others (0, 1 and 3), being practically the same (p>0.05) in Autumn (99.96%) and in Summer (99.81%). On average (and in weeks 1 and 3-10), the percentage of live spermatozoa was higher in Summer than in Autumn. Accordingly, the percentage of live spermatozoa decreased with age (r = -0.82, p<0.05). However, on average, sperm-cell concentration did not change between seasons (p>0.05). In conclusion, Mexican Creole roosters showed higher percentage of live spermatozoa in Summer than in Autumn. Therefore, it is advisable to select these animals of about 2.7 kg and reproduce them in Summer.

RESUMO O objetivo deste estudo foi avaliar a capacidade antioxidante, a concentração de glicose e insulina e o comportamento reprodutivo de ovelhas suplementadas com resíduo de laranja antes da inseminação. Cinquenta e cinco ovelhas multíparas foram divididas em dois currais e 15 ovelhas sem raça foram mantidas individualmente para se medir o consumo de ração. Duas dietas integrais foram administradas; T0: tratamento controle e T1: dieta com 20% de resíduo de laranja seco. Dias após o início da suplementação, as ovelhas foram sincronizadas. A suplementação foi finalizada antes da inseminação artificial e, em seguida, foi coletada uma amostra de sangue para medir a capacidade antioxidante e a concentração de glicose e insulina. Uma análise de variância foi feita para avaliar o efeito do tratamento sobre a capacidade antioxidante, a glicose e a insulina, e um teste do ji quadrado foi realizado para analisar a resposta ao estro, a porcentagem de gestação e de prolificidade. Dos nove compostos antioxidantes encontrados no resíduo laranja, a hesperidina (7,44%), o ácido clorogênico (0,50%) e o ácido protocatecuico foram os de maior concentração. O consumo alimentar, a resposta ao estro, a porcentagem de gestação, a capacidade antioxidante, a concentração de glicose e a insulina não foram afetados pelo tratamento. Conclui-se que é possível a inclusão de 20% de resíduos de laranja na dieta antes da inseminação em ovelhas.

ABSTRACT The objective was to evaluate the antioxidant capacity, glucose and insulin concentration and reproductive performance of ewes supplemented with orange residue prior to insemination. Fifty-five multiparous ewes were divided into two corrals, and 15 unbred ewes were kept individually to measure feed consumption. Two integral diets were administered; T0: control treatment and T1: with 20% of dry matter of orange residue. Ten days after the start of supplementation, the ewes were synchronized. Supplementation was finalized prior to artificial insemination, then, a blood sample was taken to measure the antioxidant capacity and glucose and insulin concentration. An analysis of variance was made to evaluate the effect of treatment on the antioxidant capacity, glucose and insulin; and to analyze the response to estrus, percentage of gestation and prolificity a ji squared test was performed. Of 9 antioxidant compounds found in the orange residue, hesperidin (7.44%), chlorogenic acid (0.50%) and protocatechuic acid had the highest concentration. Feed intake, estrus response, percentage of gestation, antioxidant capacity, and glucose and insulin concentration were not affected by the treatment. It is concluded that inclusion of 20% of orange residue in the diet prior to insemination in ewes is possible.

RESUMO Dois ensaios foram realizados para estudar a planta de Tithonia diversifolia (Td): (1) análise química e digestibilidade in vitro da matéria seca (DIVMS) de partes de plantas e (2) desempenho produtivo de cordeiros alimentados com dieta tradicional ou dieta Td (30% de Td mais 70% da dieta tradicional). As partes vegetais estudadas foram folhas (L), folhas e pecíolos (LP); folhas, pecíolos e caules (LPS). O consumo de ração, o ganho de peso e a conversão alimentar foram registrados semanalmente, durante cinco semanas de experimentação. O L apresentou maior (P<0,05) conteúdo de proteína bruta (26,7%) que o LP e o LPS (25,5 e 19,7%, respectivamente). Fibra bruta (11,2%), fibra em detergente neutro (45,4%), celulose (16,9%) e hemicelulose (33,5%) foram menores em L do que em LP (12,5, 46,7, 18,0 e 35,7%, respectivamente) e LPS (22,6, 59,2, 27,0 e 43,5%, respectivamente). O L e o LP apresentaram o maior DIVMS (89,2 e 88,2%, respectivamente vs. 77,2% do LPS). A dieta Td resultou em maior consumo de ração e maior ganho de peso e menor conversão alimentar que a dieta tradicional. Portanto, Tithonia diversifolia é uma planta forrageira de boa qualidade para cordeiros que não afeta o desempenho produtivo.

ABSTRACT Two assays were conducted to study the Tithonia diversifolia (Td) plant: (1) chemical analysis and in vitro dry matter digestibility (IVDMD) of plant parts and (2) productive performance of lambs fed a traditional diet or a Td diet (30% of Td plus 70% of the traditional diet). The plant parts studied were leaves (L), leaves and petioles (LP); and leaves, petioles and stems (LPS). Feed intake, weight gain and feed conversion were registered weekly during five weeks of experimentation. The L showed higher (P<0.05) crude protein content (26.7%) than LP and LPS (25.5 and 19.7%, respectively). Crude fiber (11.2%), neutral detergent fiber (45.4%), cellulose (16.9%) and hemicellulose (33.5%) were lower in L than in LP (12.5, 46.7, 18.0 and 35.7%, respectively) and LPS (22.6, 59.2, 27.0 and 43.5%, respectively). The L and LP showed the highest IVDMD (89.2 and 88.2%, respectively vs. 77.2% of LPS). The Td diet resulted in greater feed intake and weight gain and lower feed conversion than the traditional diet. Therefore, Tithonia diversifolia is a forage plant of good quality for lambs which does not affect the productive performance.

In this study it was investigated whether the effect of administration of Recombinant Bovine Somatotropin (bST) (two days before the end of progestin treatment) on synchronizing estrus, estrus, fertility, prolificacy and mode of delivery in Pelibuey sheep. It was an inserted a intravaginal device impregnated with progesterone (P4 CIDR 0.3 g) for nine days on180 sheep with 4 ± 0.32 years of age, the sheep were randomly assigned to one of three treatments: T1= CIDR (n= 60), T2= +250 mg of bST CIDR (n= 60) and T3= CIDR+300 48 IU eCG hours before the end of progestin (n= 60). Results showed no difference (p>0.05) between treatments in estrus synchronization response, fertility and prolificacy. The time to onset of estrus was lower (p<0.05) when applying bST (31.95 ± 2.85 h), with respect to the application of progesterone (43.67 ± 3.55 h). The number of ewes with triplets was higher (p<0.05) when applying bST (32.73 %) and less where it was applied eCG (13.47 %). The administration of 250 mg of bST in Pelibuey sheep, two days before the end of progestin, reduces the time to onset of estrus and increases the proportion of triplets.

Con la finalidad de estudiar si la administración de la Somatotropina Bovina Recombinante (bST) dos días antes del retiro del progestágeno, tiene efecto en la sincronización de estros, inicio del estro, fertilidad, prolificidad y tipo de parto en ovejas Pelibuey, a 180 ovejas de 4,0 ± 0,32 años de edad, se les inserto un dispositivo intravaginal impregnado con progesterona (CIDR P4 0,3 g), por nueve días. Dos días antes del retiro del dispositivo, las ovejas se asignaron aleatoriamente a uno de tres tratamientos: T1 = CIDR(n=60); T2= CIDR+ 250 mg de bST (n= 60) y T3= CIDR+300 UI eCG 48 horas antes del retiro del progestágeno (n= 60). La respuesta en la sincronización de estros, fertilidad y prolificidad no fue diferente (p>0,05) entre tratamientos. el tiempo a inicio del estro fue menor (p<0,05) al aplicar bST (31,95 ± 2,85 h) con respecto a la administración de progesterona (43,67 ± 3,55 h). La cantidad de ovejas con partos triple fue mayor (p<0,05) al aplicar bST (32,73 %) y menor al administrar eCG (13,47 %). La administración de 250 mg de bST en ovejas Pelibuey, dos días antes retirar el progestágeno, reduce el tiempo a la presentación del estro y aumenta la proporción de partos triples.