Performance, Digestibility And Ruminal Morphophysiology Of Water Buffaloes Finished In Feedlot

Abstract This study evaluated the digestibility and ruminal morphophysiology of water buffaloes finished in feedlot and receiving concentrate diet ad libitum (corn silage, ground corn, cottonseed meal, urea, and premix). Seventy-eight male water buffaloes of different genetic groups (GG; Jafarabadi, Mediterranean, and Murrah; n = 26 animals for each GG; 378.57±42.76 kg of initial body weight - BW) were used. The digestibility evaluation was performed and the feces samples were collected after 84 days, for 13 consecutive days [10 days of data collection for dry matter intake (DMI) calculation, and three days of feces collection]. Samples of the ruminal epithelium were collected for morphological and histological analysis of the ruminal papillae postmortem. There was no effect of the GG for digestibility (P = 0.15). Jafarabadi and Mediterranean showed superior feedlot performance compared to Murrah (P < 0.01) for average daily gain (1.57, 1.60, and 1.29, in kg/day, for Jafarabadi, Mediterranean, and Murrah, respectively; SEM=0.07). In addition, Mediterranean presented higher values for DMI than the other GG (2.14, 2.47, and 2.21, in %BW, for Jafarabadi, Mediterranean, and Murrah, respectively; SEM=0.07). Effect of the GG was verified for the variable epithelium (P < 0.01), for which Murrah obtained higher value than other GG (49.14, 48.99, and 55.46, in µm, for Jafarabadi, Mediterranean, and Murrah, respectively; SEM=4.97). Tendency was detected for papillae width (P = 0.09) for which Mediterranean showed a smaller value compared to Jafarabadi, while Murrah did not differ from both GG (0.338, 0.303, and 0.316, in mm, for Jafarabadi, Mediterranean, and Murrah, respectively; SEM=0.016). The mean number of papillae showed tendency for the GG (PP = 0.09) with the highest value for the Mediterranean (56.48, 66.31, and 58.04, for Jafarabadi, Mediterranean, and Murrah, respectively; SEM=13.88). In conclusion, GG of water buffaloes have some differences in feedlot performance and ruminal traits; however, these characteristics do not affect digestibility. Supported by FAPESP (#2014/05473-7).