The effect of partial replacement of soyabean meal with sunflower meal on ileal adaptation, nutrient utilisation and growth performance of young turkeys.

1. A 4 x 2 factorial arrangement of treatments was used to investigate the effect of graded levels of sunflower meal (SFM; 0, 70, 140 and 210 g/kg) and enzyme supplementation on gut morphology, nutrient utilisation and growth performance of young turkeys from 0 to 8 weeks of age. The enzyme supplement used in the study contained non-starch polysaccharide (NSP)-degrading activities and supplied 500 U pectinase, 40 U cellulase, 1600 U xylanase, 800 U glucanase, 200 U mannanase, 20 U galactanase per kg diet. 2. The use of SFM resulted in an increase in the height and width of intestinal villi, and a linear decrease in crypt depth. Dry matter digestibility and energy metabolisability decreased in groups fed diets with a moderate (140 g/kg) and high (210 g/kg) SFM content. 3. A decrease in dry matter digestibility and energy metabolisability was most likely the reason for a reduction in body weights of 8-week-old turkeys fed on diets containing 140 g/kg (from 4 x 17 to 4 x 01 kg) and 210 g/kg (from 4 x 17 to 3 x 93?kg) of SFM. 4. The addition of enzyme resulted in a slight increase in villus height, a significant increase in the number of goblet cells and an increase in digestibility coefficients for crude fat. 5. The results of this study demonstrate that turkey diets can be effectively supplemented with high-quality sunflower meal at a concentration of approximately 70 g/kg. It should be noted, however, that at 8 weeks of age the body weight of turkeys fed on diets containing 140 and 210 g/kg of SFM could be lower by 4 and 6%, respectively, than in those receiving the soyabean meal-based diets.

Application of soybean meal, soy protein concentrate and isolate differing in α-galactosides content to low- and high-fibre diets in growing turkeys.

The aim of this experiment was to investigate the physiological and growth response of young turkeys (up to 8 weeks of age) to dietary replacement of soybean meal (SBM) by soy protein concentrate (PC) or protein isolate (PI). This replacement resulted in a differentiated dietary concentration of α-galactosides of over 2.5% in the SBM diet, approximately 2% with a mixture SBM and PC, 1% with a PC diet and 0.1% with a PI diet. Each treatment was applied in two ways: with lower (3.5%) or higher (5.3%) dietary crude fibre content, made by supplementation with soybean hulls. The highest and lowest body weight of turkeys was recorded both after the first and second 4-week half of the study in the PC and PI-type diets respectively. A gradual withdrawal of α-galactosides from a diet was accompanied by a decline in ileal tissue mass, ileal viscosity and activity of endogenous maltase (the latter was found to be significant at 4 weeks of age). At the same time, two-way anova revealed that an elevated level of crude fibre (HF treatment) caused an increase in ileal tissue mass (p < 0.05 after 4 weeks of feeding) as well as a decrease in activity level of intestinal sucrase and maltase. The presence of raffinose family oligosaccharides in a diet, in contrast to dietary crude fibre level, significantly affected the caecal metabolism. The rate of bacterial production of short-chain fatty acids in the caeca was distinctly diminished by dietary withdrawal of α-galactosides. In conclusion, the soy protein concentrate, in contrast to the protein isolate preparation, exerted positive effects on the turkeys' growth and gastrointestinal tract physiology and should be considered as an effective SBM substitute.

The effect of diets containing soybean meal, soybean protein concentrate, and soybean protein isolate of different oligosaccharide content on growth performance and gut function of young turkeys.

An experiment was conducted to investigate the effects of diets containing soybean meal (SBM), soybean protein concentrate (SPC), and soybean protein isolate (SPI) on growth performance and gut function of the young turkey. A total of 812 one-day-old male turkey poults were randomly assigned to 4 dietary treatments, with 7 pens per treatment and 29 birds per pen. The 4 experimental diets contained SBM, SBM-SPC, SPC, and SPI and were fed throughout the two 4-wk experimental periods. In each period, the diets were isonitrogenous and isocaloric and contained similar amounts of total and water-soluble nonstarch polysaccharides. The content of oligosaccharides differed among the diets and averaged 2.4, 1.9, 0.9, and 0.1% for SBM, SBM-SPC, SPC, and SPI, respectively. When compared with SBM, birds consuming the SBM-SPC and SPC diets had higher (P<0.05) final BW (4.32 vs. 4.45 and 4.46 kg, respectively). Incorporation of SPI as a substitute for SBM resulted in improved (P<0.05) feed utilization (from 1.76 to 1.67) but did not affect the final BW. Significant changes in cecal concentrations of short-chain fatty acids were observed and averaged 130, 103, and 89 micromol/g of digesta for the SBM, SBM-SPC, and SPC diets, respectively. This coincided with the proportional decrease in dietary oligosaccharide content (from 2.4 to 0.9%) and was further substantiated by a significant decrease in ileum weights. Feeding the SPI diet resulted in the lowest ileal and cecal tissue weights as well as the lowest cecal short-chain fatty acids concentration. There was no effect of diet on digesta pH, viscosity, and mucosal sucrase and maltase activities. Bacterial beta-glucuronidase activity was decreased (P=0.08) in the cecum (from 0.98 to 0.60 U/g) with decreased dietary oligosaccharide content. In conclusion, partial or almost complete substitution of SBM with SPC suppressed the fermentation processes in the ceca but enhanced the growth rate. Substitution of SBM with SPI significantly improved feed utilization but decreased BW of 4-wk-old turkeys with no effect on growth rate of older 8-wk-old birds.

Effect of diets with different contents of soybean alpha-galactosides and crude fibre on modification of duodenal microstructure and selected parameters of nutrient utilization in young turkeys.

The aim of the present study was to assess the physiological response of growing turkeys' duodenal surface to dietary replacement of a common dietary component--soybean meal (SBM) with a soy protein isolate (SPI), as this treatment was associated with almost complete removal of alpha-galactosides from the diet (from 2.44 to 0.15%). Additionally, the utilization of selected dietary ingredients upon dietary treatments was recorded. Effects of raffinose-family oligosaccharides were assessed as well in low- and high-fibre dietary environment (3.5 and 5.3% of crude fibre, respectively). This study revealed that the duodenal morphological parameters were differently affected by dietary treatments at different production stages, i.e. at 4 and 8 weeks of life. Although villus height/crypt depth ratio (VCR) was insignificantly decreased by high-alpha-galactoside treatment in younger 4-week birds, the presence of these oligosaccharides in the diet positively influenced the VCR index in 8-week turkeys. A similar tendency was observed when calcium retention was considered. Different contents of dietary crude fibre affected the physiological action of alpha-galactosides, including duodenal crypts depth and phosphorus retention in the 4-week birds, as well as duodenal goblet cells number and nitrogen utilization in the older turkeys. A high content of alpha-galactosides in the diet resulted in increased hydration of intestinal contents, but without a significant decline in the dry matter digestibility and utilization of nitrogen, calcium and phosphorus. Having in mind the development and physiology of the GIT, it may preliminary be concluded that in later production stages, total withdrawal of soybean alpha-galactosides from turkeys' diets does not seem to be nutritionally advisable.