EVALUATING ENERGY UTILIZATION IN SOME SELECTED NON-CONVENTIONAL FEED INGREDIENTS FOR BROILER CHICKENS AND PIGS
The objective of this thesis was to evaluate energy utilization in some selected non-conventional feed ingredient for broiler chickens and pigs. Three studies were carried out to evaluate this objective. All studies employed the randomized complete block design with 8 replicates.
Study 1 evaluated the ileal digestible energy (IDE), metabolizable energy (ME) and nitrogen-corrected ME (MEn) of 2 feed ingredients which included dry fat (DF) and stabilized rice bran (SRB) with broiler chickens using the regression method in 2 experiments. Chickens were fed a common broiler chicken starter diet from d 0 to 17 and experimental diets from d 17 to 22 post hatching. Three diets were prepared: a corn-soybean meal reference diet (RD) and two test diets containing either DF at 50 or 100 g/kg replacement in experiment (Exp.) 1 or SRB at 100 or 200 g/kg replacement (Exp. 2) of the energy-contributing ingredients in the RD. In each Exp., 192 chickens were randomly allocated to one of three dietary treatments. In Exp.1, the IDE, ME, and MEn linearly increased (P<0.001) as DF concentrations increased, while in Experiment 2, the IDE, ME, and MEn of the diets were not affected by dietary supplemental SRB. The regression-derived IDE concentration for DF and SRB were 6,047 and 3,556 kcal/kg DM, respectively. The respective ME and MEn estimates (kcal/kg DM) were 6,051 and 5,922 for DF; 3,437 and 3,193 for SRB. The results from this study showed that broiler chickens utilized between 77 to 79% and 68 to 76% of the gross energy (GE) in DF and SRB, respectively, and this suggested a strong potential for these ingredients as dietary energy sources for broiler chickens.
In Study 2, three experiments were conducted to evaluate the IDE, ME, and MEn of hydrolyzed feather meal (HFM) and flash-dried poultry protein (FDPP) with broiler chickens and to determine the digestible energy (DE) and ME of HFM and FDPP for pigs. The HFM or FDPP were incorporated into a reference diet either at 3 levels (0, 75, or 150 g/kg) in Exp. 1 and 2, or 2 levels (0 or 150 g/kg) in Exp. 3 by replacing the energy-yielding ingredients. In Exp. 1, the inclusion of HFM, linearly decreased (P < 0.05) the nitrogen corrected metabolizability although, the ME concentration in the diets were linearly increased (P < 0.05). In Exp. 2, a linear decrease was observed on the ileal digestibility of DM and energy (P < 0.05). It was also observed that the total tract retention (TTR) of DM and energy linearly increased (P < 0.05). Similarly, the ME and MEn concentration linearly increased with a P-value of < 0.001 and < 0.01, respectively. In Exp. 3, the dietary treatments significantly increased (P < 0.05) the fecal energy loss. Diet substituted with HFM had significantly higher (P < 0.001) urinary GE loss than the RD. The TTR of GE in the RD was significantly higher than those in the test diet containing 150 g/kg of HFM. The respective IDE, ME, and MEn evaluated for HFM in the current study were 4,509, 4,250, and 3745 kcal/kg DM with corresponding values of 3,221, 4,710, and 4,081 kcal/kg DM for FDPP when fed to broiler chickens. In pigs, the respective DE and ME evaluated for HFM were 4,783 and 4,405 kcal/kg DM while estimates for FDPP were 4,553 and 4,320 kcal/kg DM, respectively.
In Study 3, energy value of partially defatted black soldier fly larvae meal (BSFLM) was determined in 2 experiments with broiler chickens and growing pigs. The Exp. 1 was conducted to evaluate IDE, ME, and MEn of BSFLM with broiler chickens while Exp. 2 was conducted to evaluate the digestible energy (DE) and ME of BSFLM in growing pigs. Total collection (TC) and two index methods using either titanium dioxide (Ti) or chromium oxide (Cr) were compared. In Exp 1 and 2, three diets were prepared: a corn-soybean meal reference diet (RD) and two test diets containing BSFLM at either 100 or 200 g/kg replacement of the energy-contributing ingredients in the RD. In Exp. 1, a linear increase (P < 0.05) was observed in the IDE concentration of the diet. With increasing BSFLM, a quadratic and linear increase (P < 0.05) was also observed on the ME and MEn concentration in the diet, respectively. The regression-derived IDE, ME, and MEn concentration in BSFLM were 4,517, 4,725, and 4,238 kcal/kg DM when fed to broiler chickens. In Exp. 2, the inclusion of BSFLM resulted in linear decrease in DM digestibility and linear increase in dietary DE concentration (P < 0.05). The metabolizability of GE linearly decreased (P < 0.05) while the ME concentration quadratically increased with the increasing inclusion of BSFLM in the diet. In pigs, the regression-derived DE estimates with TC, Ti index marker, and Cr index marker were 5,010, 4,907, and 4,927 kcal/kg, respectively. The ME derived using the TC method was 4,711 kcal/kg. The result from this study is interpreted to suggest BSFLM as a potential energy feed ingredient for inclusion in diets for broiler chickens and pigs.
In summary, we could conclude that DF can be added to the list of fat source while SRB is a potential fiber source in broiler chicken diets. Also, HFM, FDPP, and partially defatted BSFLM are all potential energy sources which should be added to the list of protein sources for broiler chickens and pigs. Generally, there is a need for an overhauling of feed ingredients termed as conventional, those alternative feed ingredients that are also readily and constantly available for livestock feeding should be driven and sensitized to farmers for consideration as conventional feed ingredient.