Marko Tukša

A 28-day study involving 448 male Ross 308 broilers aimed to determine the effect of dietary rice bran (RB) and xylanase (XYL) in maize- and wheat-based diets on chicken growth, N-corrected apparent metabolizable energy (AMEn), and nutrient availability. Two isonitrogenic and isocaloric maize- or wheat-based basal diets (BDs) were formulated matching breeding recommendations. Each diet was then split in four parts: two parts BD was substituted with 75 g/kg RB and then one of the RB substituted and one of the original parts was supplemented with 16,000 XYL units/kg, resulting in a total of eight experimental dietary treatments. Each diet was fed to seven pens of eight birds per pen following randomization. The data were analyzed by ANOVA using a 2 × 2 × 2 factorial design (cereal type × RB × XYL). Enzyme supplemented RB-free wheat-based diet had greater AMEn (p = 0.002) and fiber digestibility (p = 0.007) compared to the rest. Feeding RB reduced daily feed intake (p = 0.015) and weight gain (p < 0.001) of chicks. Birds fed wheat-based diets had greater feed efficiency, coupled with an increase in starch digestibility (SD) and energy conversion ratio (ECR). The observed differences in feed efficiency were explained only by SD and ECR.

The study aimed to compare different methods assessing the nutritive value of wheat grain for broiler chickens, measured as growth performance, including wheat chemical composition, metabolizable energy (ME), starch digestibility (SD) and rate of starch digestion (RSD). Samples from wheat cultivars Bennington and Siskin were chosen for the study due to their different fibre but similar starch contents. Two cold pelleted diets including 630 g/kg of each of the wheat cultivar samples were fed ad libitum to broiler chickens 7 to 28 days of age to male Ross 308 broiler chickens. Each diet was fed to 16 raised floor pens following complete randomisation. Birds fed a diet based on Bennington were heavier, ate more and grew faster than those fed a Siskin-based diet (P0.05). Compared to Siskin, Bennington-based diet had greater SD in proximal (P=0.017) and distal (P=0.050) ileal segments, but no differences were detected in RSD (P>0.05). Bennington-fed birds had greater daily consumption of ME, dry matter, fat, starch (P<0.001) and nitrogen (P=0.007). The results suggest that in this study not RSD but ME and intake of digestible nutrients described better the feeding value of wheat for broilers.

An experiment was conducted to determine the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) of defatted black soldier fly larvae meal (BSM), full-fat dry larvae meal (BSL), and larvae fat (LF) for broiler chickens. The BSM, BSL, and LF contained on a g/kg basis, respectively, crude protein, 459, 399, 0; crude fat, 171, 240, 923; dry matter, 963, 940, 997; neutral detergent fiber, 210, 333, 0; acid detergent fibers, 95, 93, 0; and gross energy (MJ/kg), 22.04, 22.78, 38.16. An AME bioassay was performed wherein broilers were fed four experimental diets (a maize–wheat–soy basal diet and three test diets containing 100 g/kg BSM, BSL, or LF, respectively). The AME of BSM, BSL, and LF was calculated based on the differences between the AME values of basal and test diets (substitution method). The AME and AMEn for BSM, BSL, and LF were determined to be 18.20 and 17.40; 17.60 and 16.50; and 36.50 and 35.60 MJ/kg DM, respectively. There were no significant differences (p > 0.05) between nutrient retention coefficients of dry matter, N, and fat. The results showed that the examined products from black soldier fly larvae are a good source of available energy and crude protein (BSL and BSM) and can be incorporated in broiler diets as alternative protein and energy sources.