Effects of dietary restriction followed by high dietary energy or protein on compensatory growth of Ashanti Black × Large White crossbred weaner pigs
The study determined the effect of re-alimenting dietary protein or energy on compensatory growth. Eighteen Ashanti Black × Large White crossbred weaner pigs (7.5 ± 0.30 kg) were randomly assigned to one of three dietary treatments in a completely randomized design resulting in three replicate pens per treatment (n = 3) and two pigs per pen. In the first treatment, pigs were fed ad libitum a diet containing 12.0 MJ/kg of metabolizable energy (ME) and 14.4% crude protein (CP) (maintenance diet) for 56 days. In the second and third dietary treatments, pigs were fed the maintenance diet for the initial 28 days and then switched to a high protein (17.4% dry matter (DM) CP; protein) or high (14.0 MJ/kg DM; energy) diet for the rest of the 28-day period. Dry matter intake and growth performance were similar (P ≥ 0.52) among treatments during the first 28 days of restrictive feeding, but pigs re-alimented with the protein diet achieved superior (P = 0.004) DM intake, average daily gain (ADG), and feed efficiency than those fed the maintenance diet or re-alimented with the energy diet in the re-alimentation period. At the end of the entire 56-day period, pigs re-alimented with the protein diet had higher (P ≥ 0.01) live weight gains and ADG compared with those fed the maintenance diet or re-alimented with the energy diet, but DM intake was similar (P = 0.66) among treatments. It was concluded that re-alimentation with protein rather than energy can improve compensatory growth of Ashanti Black × Large White crossbred weaner pigs.