Work was undertaken to investigate the potential use of housefly (Musca domestica) larvae reared on broiler manure as a source of nutrition for poultry production in the United Kingdom. Nutritional analysis showed that larvae have a high (>45% dry wt.) protein content and a favorable amino acid profile that is rich in key amino acids, such as lysine and methionine. A broiler digestibility trial was carried out to determine the apparent ileal digestibility coefficients (AIDC) and true ileal digestibility coefficients (TIDC) of amino acids (AA) from insect larval meal (ILM) from M. domestica and fishmeal (FM) in broiler chickens. This was calculated using multiple linear regression technique based upon 3 inclusions of each protein source in a semisynthetic diet. One-hundred-forty-four day-old male (Ross 308) broilers were fed from hatch on a commercial starter diet for 20 days. Experimental diets were fed from d 21 to 28, and feed intakes were measured daily. On d 28, the trial was terminated, ileal digesta were collected for the determination of AIDC and TIDC of AA, and inflammatory responses (gizzard erosion and eye discharge) were measured. No significant differences were observed in digestibilities between protein sources for any AA. Furthermore, ILM feeding did not induce gizzard erosion or eye discharge at any inclusion. These results provide strong evidence to suggest that ILM of the common housefly can provide a successful alternative protein source to FM in broiler diets.

The G-protein coupled receptors (GPCRs) superfamily comprise similar proteins arranged into families or classes thus making it one of the largest in the mammalian genome.

There has been discussion regarding microbial phytase replacing inorganic phosphorus (P) supplementation in broiler diets. Therefore, an experiment was conducted to examine the effect of phytase supplementation on diets low in inorganic P. Ross 308 broilers (n = 288) were fed one of 6 experimental diets in 4 phases. The control diet had 16.20, 10.90, 9.40, and 6.10 g/kg inorganic P in the Starter, Grower 1, Grower 2 and Finisher phase respectively. The remaining diets had 10.50 g/kg inorganic P in the Starter phase. Two of the diets had graded reductions in inorganic P of 5.10, 3.60, and 0.60 g/kg or 2.00, 0.50, and 0.60 g/kg for the Grower 1, Grower 2 and Finisher phase respectively, plus 500 FTU phytase. Three of the diets had inorganic P levels of 0.40, 0.50, and 0.60 g/kg for the Grower 1, Grower 2 and Finisher diets respectively and either 500, 750, or 1,000 FTU phytase. Broiler performance was analyzed at d 10, 20, 26, and 35. On d 35, ileal calcium (Ca) and P digestibility and tibia bone strength, mineralization, and mineral content were analyzed. There were no significant differences between the control diet and diet containing 1,000 FTU phytase and low inorganic P in the grower or finisher diets based on bird performance, tibia strength, and Ca and P digestibility. Birds fed the control diet had significantly higher BWG (P = 0.001), bone strength (P < 0.001) and ash content (P < 0.001) compared to birds fed the diets with 500 FTU or 750 FTU phytase and low inorganic P in the grower and finisher stages. This may be due to incomplete dephosphorylation of the inositol ring of phytate with these doses of phytase, but with 1,000 FTU phytase there was almost complete phosphate hydrolysis of each phytate. This study showed that relying on phytase alone to ensure full supply of P in broiler diets is viable in finisher diets but is not recommended in grower diets unless phytase is supplied at doses of 1,000 FTU or greater.

In this study, we assessed uptake and potential efficacy of a novel, pH neutral form of silicon supplement in vitro and using broiler chickens as a model species. In vitro bioavailability of this supplement was significantly higher than other commercial supplements tested, all of which claim available silica content. To confirm bioavailability of the new supplement in vivo, a broiler chick feeding trial reported blood uptake that was significantly higher than a Bamboo-derived silicon supplement. We assessed dose response of the novel supplement in a further study with increased dose related levels of silicon being detected in the blood and tibia. We found tibia and foot ash residue as a percentage of dry mass was higher with inclusion of the novel supplement in the diet, particularly in young birds and that this was followed by significant increase in tibia breaking strength. This novel supplement may therefore have applications in the improvement of bone integrity, with implications for the reduction of lameness in broilers. These results indicate the novel silica supplement is readily absorbed in chicks, and transported in the blood supply to sites such as the skeleton due to it being present in a non-condensed, monomeric form. There is potential for wider application of this silica supplement in other species where bone breakages are a problem, including high performance sport.

27 Young broilers have an underdeveloped ability for lipid digestion. The potential of lecithin and 28 lysolecithin to improve lipid digestion and growth performance was investigated in 3 29 experiments: an in vitro model that mimics the intestinal conditions of the chick, a digestibility 30 trial with chicks (5 to 7 days of age), and a performance trial until 21 days of age. In Experiment 31 1, palm oil (PO), palm oil with lecithin (PO+L), and palm oil with lysolecithin (PO+LY) were 32 subjected to in vitro hydrolysis and applied to Caco-2 monolayers to assess lipid absorption. 33 The in vitro hydrolysis rate of triglycerides was higher in PO+LY (k= 11.76 × 10-3 min-1) than 34 in either PO (k= 9.73 × 10 3 min 1) or PO+L (k= 8.41 × 10 3 min 1), and the absorption of 35 monoglycerides and free fatty acids was highest (P<0.01) for PO+LY. In Experiment 2, 90 36 broilers were assigned to three dietary treatments: a basal diet with 4% palm oil, and the basal 37 diet supplemented with either 250 ppm lecithin or lysolecithin. ATTD of crude fat was higher 38 in broilers supplemented with lysolecithin, but was lower in broilers supplemented with 39 lecithin. DM digestibility and AMEn in birds supplemented with lysolecithin were significantly 40 higher (3.03% and 0.47 MJ/kg, respectively). In Experiment 3, 480 broilers were randomly 41 allocated to four dietary treatments: basal diet with soybean oil (2%), basal diet with lecithin 42 (2%), soybean oil diet with 250 ppm lysolecithin, or lecithin oil diet with 250 ppm lysolecithin. 43 Lecithin diets significantly reduced weight at day 10 and 21 compared with soybean oil. 44 However, the addition of lysolecithin to lecithin-containing diets significantly improved bird 45 performance. The results of these studies show that, in contrast to lecithin, lysolecithin is able 46 to significantly improve the digestibility and energy values of feed in young broilers.