A total of 180 broiler chickens were fed 1 of 3 diets from day-old to slaughter at 35 d: a control diet with 35% soybean meal (SOY) or diets in which either 6% basic bacterial protein meal (BBP) or 6% autolysed bacterial protein meal (AUT) partially replaced soybean meal protein. Ileal and total tract apparent amino acid digestibility were examined in 5 chickens per diet using TiO(2) as an inert marker. Chickens fed the diets with bacterial protein had higher weight gain and feed consumption than control chicks during the first 3 wk, but there were no differences in growth or feed intake during the last 2 wk or during the total experimental period. The birds fed the BBP diet showed more efficient feed conversion compared with chickens fed the SOY and AUT diets. Litter quality at 5 wk was poorer in pens where the chickens were fed the AUT diet compared with the other 2 treatments. There were no differences among diets in the dressing percentage. Ileal amino acid digestibility at 5 wk of age revealed only minor differences between diets. There was a tendency toward lower ileal digestibility (0.12 > P > 0.07) of Arg, Lys, Met, and Phe in the AUT diet compared with the SOY diet, whereas there were no differences between the SOY and BBP diets. Total tract amino acid digestibilities at 5 wk were similar or slightly lower than the ileal digestibilities within diets. Total tract amino acid digestibility at 2 wk was similar to the total tract amino acid digestibility at 5 wk. The diets containing bacterial protein showed lower total tract digestibility of most amino acids compared with the SOY diet. It was concluded that 6% of either basic or autolysed bacterial protein can replace soybean meal in diets for broiler chickens without impairing growth performance, and the basic bacterial protein seemed to be a slightly better substitute than the autolysed bacterial protein.

Skrede, A., Faaland Schøyen, H., Svihus, B. and Storebakken, T. 2003. The effect of bacterial protein grown on natural gas on growth performance and sensory quality of broiler chickens. Can. J. Anim. Sci. 83: 229-237. Bacterial protein meal (BPM) produced from natural gas by Methylococcus capsulatus (Bath), Alcaligenes acidovorans, Bacillus brevis and Bacillus firmus was studied as a protein source for broiler chickens. Three experiments from day-old to slaughter at 35 d were carried out. In exp. 1, BPM was fed at 0, 20, 40, 60, 80 and 100 g kg -1 diet (as fed) replacing soybean meal protein. Levels of BPM up to 60 g kg -1 had no effect on 0-5 wk gain, while the 80 and 100 g kg -1 levels significantly reduced gain, especially in the 0-2 wk period. In exp. 2, chickens were fed diets containing 0, 30, 60 and 90 g kg -1 BPM and two protein levels, 23 and 21 g kg -1 . The highest level of BPM significantly reduced growth, independent of protein level, whereas growth responses to lower levels of BPM were similar to the control diet. In exp. 3, 90 g kg -1 BPM in diets containing 23 g kg -1 protein had no negative effect on growth, but significantly reduced the abdominal fat pad. Overall, substitution of soybean meal protein with increasing levels of BPM significantly lowered feed-to-gain ratio during the last part of the feeding period. Sensory analysis of thigh meat after 2 mo of frozen storage (exp. 1) showed that meat from 35-d-old chickens fed 60 and 100 g kg -1 BPM had less odor intensity and less rancid flavor than meat from control animals fed no BPM. Other sensory attributes were not affected by treatment. Pour cela, ils ont engraissé des oiseaux du premier jour à l'abattage, 35 jours plus tard, dans le cadre de trois expériences. Dans la première, ils ont remplacé le tourteau de soja par 0, 20, 40, 60, 80 ou 100 g de FPU par kilo d'aliment servi. Jusqu'à la concentration de 60 g, la FPU n'a aucune incidence sur le gain de poids pendant les 5 premières semaines, mais à celles de 80 et de 100 g, la FPU diminue sensiblement le gain de poids, surtout lors des deux premières semaines d'engraissement. Dans la deuxième expéri-ence, les oiseaux ont été nourris avec un aliment contenant 0, 30, 60 ou 90 g de FPU et 23 ou 21 g de protéines par kilo d'aliment. La concentration de FPU la plus élevée ralentit sensiblement le gain de poids, quelle que soit la teneur en protéines, mais les plus petites concentrations débouchent sur une réaction similaire à celle de la ration témoin. Dans la troisième expérience, la présence de 90 g de FPU par kilo dans un aliment contenant 23 g de protéines par kilo n'a pas eu d'effet négatif sur la croissance, mais a sensiblement réduit la couche de gras abdominal. Dans l'ensemble, la substitution du tourteau de soja par une quantité croissante de FPU atténue sensiblement le ratio entre la prise alimentaire et le gain de poids durant la dernière partie de la période d'engraissement. L'évaluation organoleptique de la viande du haut de cuisse après deux mois de congélation (expérience 1) indi...

No abstract

Bacterial meal (BPM) produced from bacteria grown on natural gas is a feed source containing approximately 70% CP and 10% lipids with predominantly C16:0 and C16:1 fatty acids. The effect of increasing dietary levels (0, 40, 80, or 120 g/kg) of BPM on fatty acid composition, the profile of volatiles by dynamic headspace gas chromatography-mass spectrometry, and sensory quality of frozen-stored broiler chicken thigh meat was examined. Increasing levels of BPM increased (linear, P < 0.0001) the content of saturated fatty acids, tended (linear, P = 0.05) to increase the content of monounsaturated fatty acids, and tended (linear, P = 0.08) to decrease the content of polyunsaturated fatty acids in the meat. Feeding BPM reduced (linear, P ≤ 0.03) levels of the volatile lipid oxidation products butanal, hexanal, heptanal, and nonanal in the meat during frozen storage but had no significant effects on the sensory quality parameters related to odor and flavor. The presence of antioxidants in BPM may have reduced lipid oxidation in the meat. To conclude, adding BPM to diets reduced the formation of volatile lipid oxidation products during frozen storage of the broiler thigh meat. Dynamic headspace gas chromatography-mass spectrometry was a more sensitive method in detecting early lipid oxidation compared with TBA reactive substances and sensory quality analyses in broiler thigh meat.

The effects of replacing soybean meal or fish meal with 2, 4 or 6% bacterial protein meal (BPM) on growth performance, ileal digestibility of amino acids and sensory quality of meat, were examined using 630 broiler chickens. Weight gain from 7-32 days of age did not differ significantly among the treatments. Efficiency of feed conversion was increased when BPM replaced soybean meal, and abdominal fat deposition tended to decline. Feed conversion was not affected when BPM replaced fish meal. Amino acid digestibility was unaffected or improved when BPM replaced soybean meal, whereas replacement of fishmeal with BPM resulted in similar digestibility. Sensory quality of fresh thigh meat was similar among treatments, but for freeze-stored chest meat replacement of fish meal with BPM reduced off-odour and off-flavour and increased juiciness. It was concluded that 6% BPM can replace soybean meal or fish meal protein in broiler chicken diets.