Different Energy and Protein Levels in Diet on Growth Performance, Blood Profiles, Pork Quality and Feed Cost in Growing-finishing Pig

Abstract

This study was conducted to evaluate the optimal energy and protein level in feed of growing-finishing pigs for growth, blood profiles, pork quality and feed cost. This experiment was done by a factorial design and factor 1 was two level of energy (3,150 or 3,300 kcal of ME/kg), and factor 2 was also two level of dietary protein in feed (90% of NRC CP requirements in 2012 or NRC CP requirements in 2012). Growth performance of growing-finishing pigs was improved when pigs were fed high dietary energy and high protein treatment diet (HH) both in late growing phase and the late finishing phase, respectively (P=0.03; P=0.05). Average daily gain (ADG) was increased when higher protein diets (LH and HH) were provided to growing-finishing pigs (P=0.03) and dietary protein was much more potent nutrient than dietary energy for growth of pigs during the whole experimental period. Average daily feed intake (ADFI) was also increased when pigs were fed higher protein diet particularly during growing phase (P=0.01) and this trend was maintained during finishing phase (P=0.03). Gain to feed ratio (G:F), however, was mainly affected by dietary energy (P=0.06) rather than dietary protein level (P=0.67). Blood urea nitrogen (BUN), total protein, creatinine and blood glucose were lowered when low energy and low protein diet (LL) was provided (P=0.01), resulted in an interaction (P=0.01). Although pH of pork was lowered when pigs were fed low protein treatment diet (P=0.03), but other measurements of pork quality, such as color, chemical analysis and TBARS, were not affected by dietary levels of energy and protein. Feed cost per weight gain was lowered when pigs were fed high energy and low protein treatment diet however, feed cost per pig was increased when dietary protein level was increased (P=0.01). Although total feed cost to 110kg of body weight was the lowest in low energy and low protein treatment (LL), days to market weight from 27.22 to 110kg was the shortest in high energy and high protein treatment (HH) among dietary treatments. Even though feed cost could be saved in LL treatment, days to market weight was delayed about 19 d compared to HH treatment subsequently LL treatment would not be efficient feed formulation for growing-finishing pigs. Consequently, this experiment demonstrated that high protein diet resulted in improved growth performance in growing pigs but high energy (3,300 kcal of ME/kg) and low protein (90% of NRC(2012)) diet would be desirable feed formulation based upon feed cost, days to market weight and pork quality.