No abstract

Tannins can cause beneficial or harmful nutritional effects, but their great diversity has until now prevented a rational distinction between tannin structures and their nutritional responses. An attempt has been made to study this problem by examining the octanol-water solubilities of tannins. A relatively simple HPLC method has been developed for screening mixtures of plant tannins for their octanol-water partition coefficients (Kow coefficients). Tannins were isolated from the fruits and leaves of different Acacia, Calliandra, Dichrostachys, and Piliostigma species, which are known to produce beneficial or harmful effects. The Kow coefficients of these tannins ranged from 0.061 to 13.9, average coefficients of variation were 9.2% and recoveries were 107%. Acacia nilotica fruits and leaves had the highest Kow coefficients, that is, 2.0 and 13.9, respectively. These A. nilotica products also have high concentrations of tannins. The combined effects of high octanol solubilities and high tannin concentrations may explain their negative effects on animal nutrition and health. It is known that compounds with high octanol solubilities are more easily absorbed into tissues, and it is, therefore, proposed that such compounds are more likely to cause toxicity problems especially if consumed in large quantities. According to the literature, tannins in human foods tend to have low Kow coefficients, and this was confirmed for the tannins in Piliostigma thonningii fruits. Therefore, unconventional feeds or browse products should be screened not only for their tannin concentrations but also for low octanol-water partition coefficients in order to identify nutritionally safe feeds and to avoid potentially toxic feeds.

The present study investigated the effect of partial replacement of soybean meal (Glycine max) with canola meal (CM) (Brassica napus) on the growth performance, haematology, serum biochemistry and meat quality characteristics of female Japanese quails in a 35-day feeding trial. One hundred and forty 6-week-old quails 158.28 ± 11.919 g were randomly allocated to 5 isonitrogenous and isoenergetic experimental diets: control diet (CM0; with no CM inclusion); CM0 with 2.5% (CM25), 5.0% (CM50), 12.5% (CM125) and 17.5% (CM175) soybean meal replaced with CM. Average weekly gain (AWG) and feed conversion efficiency (FCE) were determined. Haematology, serum biochemistry, carcass traits and meat quality parameters were determined at slaughter. Quails fed CM175 had the lowest (P < 0.05) feed intake whereas no differences were observed among the other 4 diets. No dietary effects on AWG, FCE and haematological parameters were observed. Serum biochemical parameters were not influenced by diets with the exception of alkaline phosphatase (ALP), where quails fed CM25 had higher ALP (161.0 U/L) than those fed CM0 (37.25 U/L). Quails fed CM25 had the highest chroma (7.39) while those fed CM125 had the lowest (3.58) at 24 h post-slaughter. Diets had no influence (P > 0.05) on cooking losses and peak positive force of quail meat. It was concluded that CM can replace soybean in quail diets up to 12.5% without compromising growth performance, health and quality of meat. Inclusion levels beyond 12.5% promoted poor voluntary feed intake and thus may require feed additives to enhance utilization.

No abstract

The use of insect meals in place of soybean meal in diets is critical for sustainable intensification of poultry production, but the utility of this alternative dietary protein source is unknown for the Jumbo quail. Therefore, this study investigated the effect of partial substitution of soybean with black soldier fly larvae (BSFL) meal on feed intake, physiological, and meat quality parameters of Jumbo quails. Three hundred and fifteen mixed-gender quails (53.8 ± 5.19 g live-weight) were reared on five isonitrogenous and isoenergetic experimental diets formulated by replacing soybean products with BSFL meal at 0 (BSFL0), 25 (BSFL25), 50 (BSFL50), 75 (BSFL75), and 100 (BSFL100) g/kg. Feed intake, body weight gain, gain-to-feed ratio (G:F), blood parameters, and carcass and meat quality traits were determined. Quadratic trends were observed for overall feed intake (y = 605 (±17.56) + 2.1 (±0.82)x − 0.02 (±0.008)x2; R2 = 0.20; p = 0.023) and overall body weight gain (y = 155 (±4.70) + 0.57 (±0.22)x − 0.005 (±0.002)x2; R2 = 0.22; p = 0.026) in response to BSFL levels. However, there were neither linear nor quadratic trends for meat quality and blood parameters, except for albumin-to-globulin ratio. Only gizzard size linearly increased (y = 0.05 (±0.004)x + 2.3 (±0.09); R2 = 0.18; p = 0.04) with BSFL levels. We concluded that BSFL meal could replace soybean products in Jumbo quail diets at 54 g/kg without compromising weight gain and meat quality.