Energy Evaluation of a Yeast Single-Cell Protein Product for Young Pigs

Abstract

A 28-day comparative slaughter trial, using 16 pigs initially weighing 5 kg and 21 days of age, was conducted to determine energy values of a yeast single-cell protein (SCP) product. Pigs were fed a diet containing 42.6% SCP at 3, 4 or 5% of body weight daily. The diet was formulated to supply all known nutrients in adequate amounts if fed at 3% of body weight. Increasing feeding level linearly increased: average daily gain (P<005), nitrogen balance (P<.005), nitrogen retention as a percentage of nitrogen digested (P<.05) and decreased feed:gain (P<.05). Apparent dry matter, energy and nitrogen digestibility coefficients were not greatly affected by feeding level. Average energy values of the yeast SCP product were (kilocalories per gram of dry matter): gross energy (GE), 4.67; digestible energy (DE), 3.91; metabolizable energy (ME), 3.65; and net energy (NE), 1.79. The pigs utilized 49% of ME for NE of maintenance and production. The estimate of NE for maintenance calculated from previous trials was 71 kcal/day/W.75.