Resumen Diversas semillas de oleaginosas son fuente de ácidos grasos esenciales indispensables para cubrir las funciones básicas en el organismo. El estudio tuvo como objetivo evaluar el efecto de la inclusión de semilla de linaza (Linum usitatissimum) en la dieta de conejos por medio del perfil metabólico. Se utilizaron 20 machos de la raza Nueva Zelandia de 8 meses de edad. Distribuidos en cuatro grupos, recibieron niveles de semilla de linaza (L. usitatissimum) en la dieta total: 0 %, 3 %, 6 % y 9 %, durante un período de 88 días. Los animales se sometieron a colecta de sangre cada 22 días para determinar glucosa, colesterol total, lipoproteínas de alta densidad (HDL), triglicéridos, lipoproteínas de muy baja densidad (VLDL), lipoproteínas de baja densidad (LDL), creatinina y urea. Los datos se evaluaron por análisis de varianza y de regresión con 5 % de significancia. La inclusión de semilla de linaza (L. usitatissimum) en la dieta presentó comportamiento cuadrático positivo para concentración plasmática de glucosa y colesterol total. No hubo diferencia significativa entre los tratamientos para la concentración plasmática de triglicéridos, lipoproteínas de baja densidad (LDL), lipoproteínas de muy baja densidad (VLDL) urea. Hubo comportamiento cúbico para lipoproteínas de alta densidad (HDL) y creatinina. La inclusión de linaza (L. usitatissimum) en la dieta no presentó efecto hipercolesterolémico en estos animales.

Abstract Many oilseeds are a source of essentials fatty acids that are necessary for the coverage of the basic functions in the organism. The study aimed to evaluate the effect of flaxseed (Linum usitatissimum) inclusion in the diet of rabbits through the metabolic profile. Twenty males of the New Zealand breed of 8 months were used. Divided in four groups, they received flaxseed (L. usitatissimum) levels in the total diet: 0 %, 3 %, 6 % y 9 %, for a period of 88 days. The animals were subjected to a blood collection every 22 days to determine glucose, total cholesterol, high density lipoprotein (HDL), triglycerides, very low-density lipoprotein (VLDL), low density lipoprotein (LDL), creatinine and urea. The data were evaluated by analysis of variance and regression with 5 % significance. The inclusion of flaxseed (L. usitatissimum) in the rabbit diet showed a positive quadratic effect for plasmatic concentration of glucose and total cholesterol. There was no significant difference between treatments for plasma concentration of triglycerides, low- density lipoproteins (LDL), very low - density lipoproteins (VLDL) and urea. There was a cubic effect for cholesterol- and creatinine. The inclusion of flaxseed (L. usitatissimum) in the diet had hypercholesterolemic effect in these animals.

Resumen El objetivo de este trabajo fue evaluar el efecto de la semilla de linaza (Linum usitatissimum) en la calidad física y morfológica del semen fresco y refrigerado de conejos. Se emplearon 20 machos Nueva Zelandia distribuidos en grupos según niveles de inclusión de semilla en su dieta durante 100 días: 0%, 3%, 6% y 9%. 15 días después de iniciar el suministro de la dieta se realizaron colectas seminales una vez por semana con vagina artificial y una hembra como maniquí. Para la evaluación física y morfológica se diluyó en medio Tris-yema y refrigerado a 5 °C; se valoró la motilidad espermática progresiva, el vigor espermático y la morfología espermática a las 0, 2, 12, 24, 48 y 72 horas post-refrigeración. La información fue analizada mediante análisis de varianza y de regresión al 5% de significancia. Para la morfología, volumen, color y aspecto seminal del semen fresco (p > 0,05) no hubo diferencia. Para volumen, turbidez, motilidad, vigor y concentración, hubo valores medios de 0,92 ± 0,24 mL; 0,86 ± 0,35; 76,58 ± 7,13%; 3,37 ± 0,28 y 205,75 ± 20,77 × 106 sptz, respectivamente. Hubo diferencia para motilidad y vigor espermático a las 0, 2, 12, 24, 48 y 72 horas post-refrigeración (p < 0,005). Se concluyó que la inclusión de hasta 9% de semilla de linaza en la dieta de conejos no alteró los parámetros físicos y microscópicos evaluados en este estudio en semen fresco y refrigerado de conejo.

Abstract The aim of this study was to evaluate the effect of flaxseed (Linum usitatissimum) on the physical and morphological quality of fresh and refrigerated rabbit semen. Twenty New Zealand males were used, and distributed in four groups according to the level of inclusion of flaxseed in the total diet for 100 days: 0 %, 3 %, 6 %, and 9 %. Fifteen days after starting the supply of the diet, seminal collections were made once a week with an artificial vagina and a female as a dummy. For the physical and morphological evaluations, the semen was diluted in Tris-Egg Yolk medium and cooling at 5 °C; progressive sperm motility, and spermatic vigor and morphology were assessed at 0, 2, 12, 24, 48, and 72 post-cooling hours. This information was analyzed through analyses of variance and regression at 5 % significance. For the morphology, volume, color, and seminal appearance of fresh semen (p > 0.05), there was no difference. For volume, turbidity, motility, vigor, and concentration, average values of 0.92 ± 0.24 mL; 0.86 ± 0.35; 76.58 ± 7.13 %; 3.37 ± 0.28, and 205.75 ± 20.77 x 106 sptz were recorded, respectively. There were differences for motility and vigor at 0, 2, 12, 24, 48, and 72 post-cooling hours (p > 0.005). In conclusion, the inclusion of up to 9 % flaxseed in the rabbit diet did not alter the physical and microscopic parameters evaluated in this study in fresh and refrigerated rabbit semen.

The substitution of equine chorionic gonadotropin (eCG) by follicle-stimulating hormone (FSH) in protocols for synchronization of ovulation in Santa Inês ewes was assessed. Ten females were submitted to the insertion of intravaginal sponges containing 60 mg medroxyprogesterone acetate for 10 days; after this period sponges were withdrawn and the animals were randomly divided into two groups. Group 1 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 300 UI eCG; Group 2 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 20 mg FSH. Interval between sponge withdrawal and estrus beginning was 27.7 h and 35.9 h for eCG and FSH, respectively. Interval between sponge withdrawal and the end of estrus was 55.8 h for eCG treatment and 55.6 h for FSH treatment. Estrus length was 29.3 h and 19.6 h, for eCG and FSH treatments, respectively. The biggest follicle and the second in size measured 0.74 cm and 0.54 cm for eCG treatment, whereas for the FSH treatment they measured 0.73 and 0.50 cm. The interval between the beginning of estrus and ovulation was similar within all groups: 21.0 h for eCG treated ewes and 25.2 h for the ones treated with FSH. Ewes treated with eCG presented an interval of 47.5 h between sponge withdrawal and ovulation, while the ones treated with FSH presented a 61.1 h interval. Ovulation occurred 8.3 h before the end of estrus in the eCG group. On the other hand, ewes treated with FSH ovulated 5.5 h after the end of estrus. Estrus and ovulation were efficiently synchronized in Santa Inês ewes by using long-term progestogen protocol associated to the administration of 20 mg FSH, along with Prostaglandin F2α (PGF2α) at the moment of sponge withdrawal, thus substituting the use of eCG.