299 J. Anim. Sci Vol. 98, Suppl. S4 PSVII-16 Prediction equations of the carcass physical composition of water buffaloes. Felipe de Barros 1 , André M. Castilhos 1 , Caroline L. Francisco 1 , Aline S. Aranha 1 , Amanna G. Jacaúna 1 , Patricia A. C. Luz 1 , Vanessa R. M. Jacob 1 , Camila S. Oliveira 1 , Tania V. Paula 1 , Andre M. Jorge 1 , 1 São Paulo State University - Unesp, School of Veterinary Medicine and Animal Science - FMVZ, Department of Animal Production and Preventive Veterinary Medicine - DPAMVP This study determined equations to estimate the phys- ical components of the buffalo carcass using bio- metric measurements performed in vivo, carcass traits performed postmortem, and the set of both meas- urements. Seventy-fve non-castrated males (25 of each genetic group: Jafarabadi, Mediterranean and Murrah), with means of initial body weight and age of 314 ±117 kg and 390 ±58 days, respectively, were used. The animals were allocated in collective pens and received feeding ad libitum for 240 days. Ultrasound assessments [(backfat thickness (BFT); Ribeye area (REA)], weight, hip height (HH) measurements, and body condition score were performed every 28 days, and tested as independent variables. The postmortem measurements tested as independent variables were carcass length (CL, cm), carcass depth (CD, cm), cold carcass weight (CCW), hot carcass weight (HCW), and carcass compactness index (CCI, kg/cm). The empty body weight (EBW) was also obtained and subse- quently used in the equations. The percentage of tis- sues which comprise the carcass was determined by the physical separation. The equations to estimate the physical composition of the carcass were developed using the stepwise regression method and Mallows’ Cp criterion, and processed by the REG procedure in SAS. The best prediction equations were those which used both independent variables obtained in vivo and postmortem, namely: Muscle, kg = 16.17 - 0,042×EBW + 0.211×CCW + 49.309×CD + 0.210×HCW - 35.570×HH (R² =0.91; RMSE =3.448; Cp =4.864); Fat, kg = 29.471 + 0.07×EBW - 33.716×CL + 0.285×BFT – 11.080×CD (R² =0.77; RMSE =2.151; Cp =2.568); Bone, kg = -34.261 + 20.380×CL + 18.356×HH + 0.011×EBW (R² =0.87; RMSE =1.181; Cp =2.218). In conclusion, the equations obtained from models with both in vivo and postmortem measurements present high prediction and can be used effciently in the esti- mate of the physical components of the water buffalo carcass. Supported by FAPESP (#2014/05473-7). Keywords: Buffalo, carcass, physical composition PSVII-11 Fecal parameters as indicators of starch digestibility and feedlot performance of water buffaloes. Tania V. Paula 1 , Caroline L. Francisco 1 , André M. Castilhos 1 , Paulo R. L. Meirelles 2 , Amanna G. Jacaúna 1 , Hugo L. Correa 1 , Camila S. Oliveira 1 , Felipe de Barros 1 , Vanessa R. M. Jacob 1 , Andre M. Jorge 1 , 1 São Paulo State University - Unesp, School of Veterinary Medicine and Animal Science - FMVZ, Department of Animal Production and Preventive Veterinary Medicine - DPAMVP, 2 São Paulo State University - Unesp, School of Veterinary Medicine and Animal Science - FMVZ, Department of Breeding and Animal Nutrition - DMNA This study evaluated fecal parameters indicative of starch digestibility of water buffaloes (Bubalus bubalis) of three genetic groups (GG: Jafarabadi, Mediterranean, and Murrah). Seventy-eight non- castrated males [n = 26 of each GG; 200 kg of ini- tial body weight (BW); 210 days of age] were used. Animals were fnished in feedlot, receiving a diet rich in starch [38.76% in dry matter (DM) basis]. Samples of feces, diet offered, and orts were collected for di- gestibility test during 3 consecutive days. Diet sam- ples were incubated in situ in the rumen of cannulated buffaloes. The remaining material was submitted to analysis to quantify the indigestible neutral deter- gent fber levels. Fecal starch (FS) determination was performed by near infrared refectance spectroscopy. Final BW (BW, kg), metabolic BW (BW0.75, kg0.75), average daily gain (ADG, kg/day), DM intake (DMI, in kg/day, and %BW) were recorded. Data were ana- lyzed using MIXED and CORR procedure in SAS, with signifcance considered if P ≤ 0.05. Starch digest- ibility and FS concentration are not infuenced by GG (P ≥ 0.23), unlike fecal DM and fecal pH (P ≤ 0.04; Table 1). Although weak, negative correlations were detected between FS and BW (r = -0.247; P = 0.05) and BW0.75 (r = -0.261; P =0.03), as well as between fecal DM and BW (r = -0.245; P = 0.05), ADG (r = -0.341; P < 0.01), DMI, kg/day (r = -0.374; P < 0.01), and DMI, %BW (r = -0.335; P < 0.01) variables. The results dem- onstrate that there are differences among GG of water buffaloes regarding fecal parameters. Furthermore, the high FS content and the low fecal pH may indicate the low capacity of water buffaloes to digest starch. Thus, the research results provide evidence that water buf- faloes are not able to use high-grain diets, and fecal