Nutrient utilisation, growth performance and blood metabolites in Murrah buffalo calves (Bubalus bubalis) divergently selected for residual feed intake

Abstract

The aim of this study was to evaluate differences in efficiency of feed utilisation between buffalo calves with low and high residual feed intake (RFI) by comparing feed intake, nutrient digestibility, growth traits and blood metabolites. Eighteen male Murrah buffalo calves (aged 4-6 months; 70 ± 1.0 kg body weight) were fed ad libitum with a total mixed ration for 120 d. Based on linear regression models involving dry matter intake (DMI), average daily gain (ADG) and mid-test metabolic body size, calves were assigned into low and high RFI groups. The RFI varied from -0.33 to +0.28 kg DM/d with an average RFI of -0.14 and 0.14 kg DM/d in low and high RFI calves, respectively. Calves had a mean DMI of 1.9 and 2.4 kg/d and an ADG of 0.5 and 0.6 kg/d in low and high RFI groups, respectively. Low RFI calves ate 19.0% less DM each day and required significantly less metabolisable energy for maintenance compared with high RFI calves (12.5 vs. 16.7 MJ/d). Nutrient digestibility and nitrogen balance did not differ among low and high RFI calves. In more efficient animals (low RFI calves) higher (p < 0.05) plasma level of growth hormone, insulin-like growth factor-1 (IGF-1), triiodothyronine (T3) and lower concentration of thyroxin hormone were detected. No significant differences in levels of insulin, hydroxyproline, plasma and urine creatinine, total protein and albumin between high and low RFI groups were found. Blood metabolites showed significant (p < 0.05) differences at initial and final stages of study in both groups. At final stage of study, RFI showed negative correlations with growth hormone, IGF-1, T3, urine creatinine and albumin. Low RFI buffalo calves are more efficient in feed utilisation and the differences in blood metabolites are probably due to differences in feed intake and body metabolism.

Buffalo heifers selected for lower residual feed intake have lower feed intake, better dietary nitrogen utilisation and reduced enteric methane production

“…() and Sharma et al. () recorded a similar trend in intake, excretion and nitrogen balance in buffalo calves divergently selected for low and high RFI. Nkrumah et al.…”

“…() and Sharma et al. () also did not find any difference in digestibility in buffalo calves, possibly due to a smaller difference in RFI among experimental animals. Richardson, Herd, Archer, and Arthur () and Cruz, Rodríguez‐Sánchez, Oltjen, and Sainz () also observed no difference in DM digestibility between low and high RFI groups of Angus steers.…”

“…In the present study, low RFI heifers consumed less feed compared to the high RFI group, yet the growth rate of the two groups was comparable. Recently, a feeding trial was conducted in male calves and it was concluded that over the course of a 99-day trial period, low RFI calves consumed less feed (1.9 kg DM/day) compared to high RFI calves (2.4 kg DM/day), yet performed in a comparable manner in terms of growth rate (Sharma et al, 2016). Bose et al (2014) also observed a lower DMI in low RFI Murrah buffalo calves than that of calves of a high RFI group (2.30 vs. 2.52 kg/day).…”

“…Furthermore, traditional feed efficiency measurement methods are moderately heritable and have a limited value when used as a genetic selection tool to improve feed efficiency (Schenkel, Miller, & Wilton, 2004). To overcome the limitations of traditional methods, residual feed intake (RFI) has become used as a preferred measure of feed efficiency across the different livestock production systems (Archer, Richardson, Herd, & Arthur, 1999;Bose, Kundu, Tho, Sharma, & Sontakke, 2014;Koch, Swiger, Chambers, & Gregory, 1963;Sharma, Kundu, Prusty, Datt, & Kumar, 2016). RFI is defined as the difference between the actual and expected feed intake of an animal based on its body weight and growth rate over a specific period (Basarab et al, 2003).…”

Feed utilization, blood metabolites and ingestive behavior in Sahiwal calves divergently selected for low and high residual feed intake

“…ME requirements were calculated as per the NRC (2001) feeding standard. Observed and required MEm and MEg were calculated by the following equations (SHARMA et al, 2016 (AOAC, 2005). Neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) were determined according to the method of VAN SOEST et al (1991).…”