Abstract #T259

# T259
Body condition score, subcutaneous fat and reproductive performance relationship in Bos indicus cows in a tropical region of Mexico.
Ivette Rubio1, Victoria Blas1, Manuel D. Corro*1, Clara Murcia1, Carlos S. Galina1, 1Faculty of Veterinary Medicine and Zootechnics National Autonomous University of Mexico, Mexico, DF, Mexico.

With the aim of evaluate the relationship between body condition, subcutaneous fat and reproductive performance in Bos indicus cattle in the Mexican tropics. Sixty multiparous cows were selected, with an average of 186.5 ± 90.8 d postpartum, synchronized with intravaginal device with natural progesterone. Body condition (BCS) scale 1–9, subcutaneous body fat (BF) by ultrasonography and live weight (LW) were measurement at 3 different times during a 90 d breeding period in all cows. The BF was defined as the subcutaneous layer of fat between the skin and fascia of the longisimus dorsi muscle and measured between the 2nd and 3rd spinous of the lumbar vertebrae. We assessed the level of progesterone blood at the beginning of the breeding season. The cows were grouped, according to the BCS, group1 (n = 25) cows with less than 4.5 and group 2 (n = 35) more than 4.5. An ANOVA was used to determine the differences between BCS, BF and LW. A linear correlation was performed to assess the association between BCS, BF and LW. At the beginning of the breeding season a larger (P < 0.05) proportion of cows in group 2 were cycling, and responded to synchronization than those in group 1. BF was higher (P < 0.05) in group 2 than group 1, 0.995 ± 0.091mm and 0.847 ± 0.114 mm, respectively. Although, there was a moderate positive relationship between BCS and BF, BCS can be a predictor of fat thickness as an indicator of body energy stored to maintain reproductive function. Because of this, Bos indicus cows with higher BF, at beginning of breeding season, would have a greater chance to become pregnant by the end of breeding season.

Key Words: body condition, subcutaneous fat, reproduction