Efecto de la adición de propilenglicol en la dieta de vaconas Holstein mestizas, sobre la actividad ovárica folicular y la calidad de ovocitos recolectados mediante Ovum Pick Up

Abstract

The energy status modifies the response of the hypothalamic-pituitary-gonadal axis, a nutritional deficit in the female influences oocyte development, increasing energy in the diet through flushing allows optimizing its performance. The present study evaluated the effect of the administration of propylene glycol as an energy source on the number of follicles and quality of oocytes in crossbred Holstein heifers raised in the high tropics. A total of 12 animals are included, aged between 24 and 32 months, with body condition of 2.5 (rated on a scale of 1 to 5 points); divided into 2 random groups, control (CON=6) and treatment (PPG=6). They were fed under a free-range system; additionally, the PPG group received 309 g of propylene glycol per day orally for 25 days; A heat synchronization protocol was applied: on day 0, an intravaginal device (IVD) for releasing progesterone was placed for 11 days, and on day 2 and 10, a luteolytic dose of PGF2α was administered., IM. To collect the COC (oocyte cumulus complex) and evaluate its quality, 4 OPU sessions were carried out every 4 days; In addition, the following metabolites were measured: glucose, triglycerides, blood urea nitrogen, total cholesterol, HDL and LDL cholesterol. The PPG group presented a greater number of total follicles (p<0.05) compared to the CON; However, there were no significant differences in either the size of the follicles or the quality of the COCs (p>0.05). Serum glucose levels increased in the PPG group (p<0.05) in contrast to the CON group; The rest of the metabolites were not different between treatments (p>0.05). In conclusion, oral administration of propylene glycol to heifers increased the number of total follicles at the ovarian level regardless of their size