Abstract #M30

# M30
Body measurements comparison between slick and wild type-haired Puerto Rican Holstein cows.
Gabriela A. Soriano-Varela*1, Melvin Mercado-Ayala1, Eduardo Matos-Padilla1, Gladycia Muñiz-Colón1, Katherine Domenech-Pérez1, Héctor L. Sánchez-Rodríguez1, 1University of Puerto Rico, Mayagüez Campus, Mayagüez, Puerto Rico.

Differences between the growth curves of slick (SLICK) and wild type-haired (WT) Puerto Rican Holstein heifers were reported in a preliminary study, suggesting that the first group reaches maturity at a smaller body size. Thus, the present study aimed to evaluate possible differences in body size-related measurements between SLICK and WT cows. For this, 24 SLICK and 54 WT lactating Puerto Rican Holstein cows (at the Agricultural Experimental Station dairy farm, Lajas, P.R.) were compared in terms of milk yield (MY), parity, and days in milk (DIM) (all 3 to verify data balance), as well as body weight (BW), withers height (WH), hip height (HH), thoracic perimeter (TP), barrel (BA), and shoulder to pin bone distance (SP). Also, the ratios of BW over the body size variables (BW/WH, BW/HH, BW/TP, BW/BA and BW/SP) were evaluated. Data were analyzed using the GLIMMIX procedure of SAS. There were no differences in MY (P = 0.9189), parity (P = 0.3660), and DIM (P = 0.6197) between SLICK and WT cows. Neither were differences in BW (P = 0.4247), WH (P = 0.4718), HH (P = 0.8833), TP (P = 0.5125), BW/WH (P = 0.3181), BW/HH (P = 0.4958), BW/TP (P = 0.5339), nor BW/BA (P = 0.9258) between SLICK and WT cows. However, SLICK cows had a larger BA (236.54 ± 2.68 vs. 231.06 ± 2.29 cm; P = 0.0363) and BW/SP (3.51 ± 0.09 vs. 3.32 ± 0.08 kg/cm; P = 0.0218), as well as a smaller SP (180.07 ± 1.82 vs. 185.20 ± 1.56 cm; P = 0.0059) than their WT counterparts. This indicates that SLICK-haired cows have a shorter body with a deeper barrel than the WT ones. Future studies should determine if such differences are related to metabolic efficiency, heat tolerance capacity, or both.

Key Words: Slick-haired Puerto Rican Holstein cow, wild type-haired Puerto Rican Holstein cow, body measurement comparison