Effect of Body Condition Score and Feed Level on Ovarian Activity, Uterine Involution and Igf-I Expression in Crossbred Cows during Postpartum
Ruiz, A.Z.; Dominguez, C.; Martinez, N.; Pinto-Santini, L.; Drescher, K.; Perez M, R.; Rojas U, J.A.; Araneda, R.
Interciencia 35(10): 752-758
ISSN/ISBN: 0378-1844 Accession: 066237223
Body condition score (BCS) at calving and feed level (FL) effects on reproductive activity werer evaluated from 15-45 days post-partum (DPP) in 18 crossbred (Bos taurus x Bos indicus) cows randomly assigned into four treatments (T) T1 (LFL): low BCS (LBCS, <2 5) and low FL; T2 (HFL): LBCS and high FL; T3 high BCS (HBCS; >= 2.5) and LFL, T4. HBCS and HFL. Reproductive activity and uterine involution were evaluated by transrectal palpation, ultrasound and plasma progesterone (P-4) levels On 45 DPP, ovaries from eight animals were collected after slaughter; and was used to classify oocyte quality as A. 13, and C. Ovarian IGF-I receptor (o-RIGF-I) expression was evaluated by Western blot. The IGF-I and its receptor expression was evaluated in liver. Non-parametric correlation and Kruskal-Wallis tests were applied, showed T effect on cervical diameter (CD, p<0.05), luteal body (p<0.05) and follicle Class 3 (>= 10mm; p<0.01), and BCS effect on C oocytes (P<0.05). T4 affected P-4 concentrations. Hepatic IGF-I receptor showed higher expression in animals under T3 and T4, however; o-RIGF-I expression was higher under T2 and T4. Remits suggest that BCS is involved in the resumption of reproductive activity, and that IGF-I acts as gonadotrophin function modulator at the ovary level in cow