In ovo feeding (IOF), injecting dietary components into the amnion about 1 d prior to internal pipping, may enhance growth by altering glycogen status. This hypothesis was evaluated with 5 IOF solutions containing protein, beta-hydroxy-beta-methylbutyrate (HMB), and carbohydrate. Four IOF treatments were arranged as a factorial of 2 levels of egg white protein (EWP; 0 and 18%) and 2 levels of HMB (0 and 0.1%). An IOF solution of carbohydrates (S; 20% dextrin and 3% maltose) was evaluated for contrast purposes. At 23 d of incubation, 1.5 mL of IOF solution was injected into the amnion of 100 eggs per treatment. At hatch, feed and water were provided ad libitum. At hatch and 3 and 7 d of age, BW were determined, and 10 poults per treatment were sampled to determine liver (LG) and pectoralis muscle (PC) glycogen content. Poults on IOF treatments A (18% EWP), B (18% EWP + HMB), and D (HMB) weighed 6.0, 2.7, and 3.3% more than the controls at hatch, respectively (P < 0.05) with an EWP x HMB interaction (P < 0.05) sustained to 3 and 7 d only in treatment D (P < 0.005). At hatch, A and D poults had greater percentages of PC (P < 0.05) than controls, and the percentage of PC in treatment D was sustained until 7 d. Total LG was enhanced by A and B at 7 d (P < 0.05) over the controls, whereas total PC glycogen was enhanced at 7 d by IOF treatment D (P < 0.05). The IOF A and S poults had greater BW than the controls at hatch only (P < 0.05). The IOF treatment A had greater LG at hatch (P < 0.05), but by 7 d, A and S had greater LG than controls (P < 0.05). Poults fed S in ovo had enhanced total PC glycogen over controls, whereas poults on treatment A had less total PC glycogen than controls (P < 0.05). The results of this experiment demonstrate that IOF of A or S poults may enhance hatch BW and glycogen status of poults during the neonatal period by inclusion of HMB.

In ovo feeding, injecting nutrients into the amnion of the avian embryo, may enhance jejunal nutrient uptake, activity of the intestinal enzymes, and posthatch growth. This hypothesis was tested in the following in ovo feeding (IOF) experiments. In experiment 1, 400 eggs were evenly distributed among 4 nutritional treatments at 23 d of embryonic development (23E) and administered 1 of 4 treatments as a 2 x 2 factorial arrangement of arginine (ARG 0, 0.7%) and beta-hydroxy-beta-methyl-butyrate (HMB 0, 0.1%). Tissues were assayed for maltase, sucrase, and leucine aminopeptidase (LAP) at 25E, hatch, and 3, 7, and 14 d. In experiment 2, all IOF procedures were repeated and treatments were administered at 21E: injected or noninjected control, 21% egg white protein (EWP), 21% EWP + 0.1% HMB. In experiment 3, two hundred eggs were evenly distributed among the following treatments at 23E: noninjected control or 0.7% ARG + 0.1% HMB + 21% EWP. Jejunal samples were assayed for glucose or alanine uptake at 23E, 25E, and hatch (experiment 2), and hatch and 7 d (experiment 3), respectively. All poults were fed a turkey starter diet ad libitum immediately upon hatching. There was a highly significant HMB x ARG interaction on jejunal sucrase, maltase, and LAP activities at 25E and 14 d. Poults in ovo (IO) fed HMB + ARG had approximately a 2- to 3-fold increase in jejunal sucrase, maltase, and LAP activities at 25E, and a 3-fold increase at 14 d, over other treatments. Poults IO fed EWP + HMB (experiment 2) had enhanced glucose uptake at 25E, whereas poults IO fed ARG + HMB + EWP (experiment 3) had enhanced alanine uptake at hatch and 7 d. These studies demonstrate that IOF ARG, HMB, and EWP may enhance jejunal nutrient uptake and digestion in turkeys.

No abstract

No abstract

No abstract