Bacterial protein meal in diets for growing pigs: effects on protein and energy metabolism

Abstract

This experiment investigated the effects of increasing the dietary content of bacterial protein meal (BPM) on the protein and energy metabolism of pigs from weaning to a live weight of 80 kg. Four litters with four castrated male pigs in each litter were used. The litters were divided into two blocks according to age. One pig from each litter was fed one of the four experimental diets. Soya-bean meal was replaced with BPM on the basis of digestible protein, and the BPM contents in the four diets were 0% (BP0), 5% (BP5), 10% (BP10) and 15% (BP15), corresponding to 0%, 17%, 35% and 52% of the digestible nitrogen (N), respectively. Four balance periods were performed, at the start of which the pigs weighed 9.5 kg, 20.7 kg, 45.3 kg and 77.2 kg, respectively. Once during each balance period, 22-h respiration experiments were performed using indirect calorimetry. Daily weight gain, feed intake and feed conversion rate were the same for all diets. The apparent digestibility of N was lower on diet BP10 than on BP0 (P ¼ 0.002), whereas the apparent digestibility of energy was similar on all diets. The retention of nitrogen did not differ between diets and was 1.50, 1.53, 1.33 and 1.46 g N per kg 0.75 per day on BP0, BP5, BP10 and BP15, respectively. Neither metabolisable energy intake nor heat production were affected by inclusion level of BPM. Retention of energy was 620 (BP0), 696 (BP5), 613 (BP10) and 664 kJ/kg 0.75 per day (BP15), the differences among diets being non-significant. The N-free respiratory quotient was similar on all diets. It was concluded that the overall protein and energy metabolism in growing pigs were not affected when up to 50% of dietary N was derived from BPM.

Bacterial protein meal in diets for pigs and minks: Comparative studies on protein turnover rate and urinary excretion of purine base derivatives

“…The collected urine was analysed for purine base derivatives. These experiments are described in detail and the results of the nitrogen balance studies are reported in Hellwing et al (2005Hellwing et al ( , 2007. The present paper presents data regarding protein turnover rate, purine base derivative excretion patterns, and betweenspecies comparative aspects.…”

“…During the balance periods, the animals were housed in metabolic cages in the laboratory at an ambient temperature of 20 -228C and a 12 h light: 12 h dark light cycle. Between the balance periods, the pigs were kept in individual pens in the stable (see Hellwing et al 2007). …”

“…This appeared both when analysing data from each species separately (Hellwing et al 2005(Hellwing et al , 2007 and in the comparative analysis. The minks excreted more urinary N than the pigs did, and therefore the utilization of digested N for retained N was considerably higher in the pigs than in the minks.…”

“…Diet formulation and chemical composition are given in Table II. For further details see Hellwing et al (2007).…”

“…In experiments with minks, chickens, and pigs it has been shown that up to 40% (minks), 20% (chickens), and 50% (pigs) of dietary N can be supplied by BPM without affecting nitrogen retention, heat production, and energy retention (Hellwing et al 2005(Hellwing et al , 2006(Hellwing et al , 2007. Similarly, production experiments with chickens (Skrede et al 2003) and pigs (Øverland et al 2001, 2004) have shown that up to one third (chickens) and 50% (pigs) of the N can be derived from BPM without negative effects on animal performance and production traits.…”