The objective of this study was to evaluate 2 types of almond hulls (prime hulls and California-type hulls) as alternative feed ingredients for broilers. A total of 560 one-day-old Cobb male chicks were randomly placed to 7 experimental treatments with 8 replicates of 10 birds each. Seven treatments consisted of a corn-soybean meal control diet and diets containing prime hulls or California-type hulls at 3, 6, and 9%. The nitrogen-corrected true metabolizable energy, crude protein, and crude fiber from prime hulls and California-type hulls were 1,624 and 1,514 kcal/kg, 4.8 and 5.0%, and 13.1 and 26.45%, respectively. During 0–19 d of age, the inclusion of the prime hulls at 3 levels had no significant effects on growth performance, but the California-type hulls at 9% increased feed intake ( P = 0.02) and feed conversion ratio ( P < 0.01), compared with control. The prime hulls at 9% decreased ( P < 0.01) ileal dry matter and ileal nitrogen digestibility, and the California-type hulls at 9% only decreased ileal dry matter digestibility, but both prime hulls and California-type hulls at 6% had no effects on ileal dry matter digestibility and nitrogen-corrected apparent metabolizable energy compared to control. In addition, inclusion of prime hulls at 3% decreased ( P < 0.01) AMEn compared with control group. There were no significant differences in cecal microbiota diversity at a phylum or genus level among treatments, but 9% inclusion rate of the California-type hulls increased ( P < 0.05) the population of certain bacteria in the genus Clostridium and Oscillospira compared with control. In conclusion, as a dietary energy and fiber source, the prime hulls can be used at up to 9% without a negative effect on body weight gain, whereas the California-type hulls can be used up to 6%.

The objective of this study was to evaluate 2 varieties of almond hulls (prime and California type hulls) as an alternative feed ingredient on the performance, egg quality, nutrient digestibility, and body composition using a total of 100 23-week-old Hy-Line W36 hens. Treatments consisted of a control diet based on corn and soybean meal; T2 and T3 were formulated to contain 7.5 and 15% of prime hulls; and T4 and T5 contained 7.5 and 15% of California type hulls. Inclusion of prime hulls and California type hulls had no effects on feed intake, egg laying rate, and feed conversion ratio, but California type hulls at 7.5% decreased ( P < 0.001) body weight gain compared to the control. Prime hulls at 7.5% and California type hulls at both levels improved ( P ≤ 0.022) AMEn and N digestibility. Both prime hulls and California type hulls had no effects on egg size, specific gravity, Haugh unit, and percentages of yolk, albumen and shell, but yolk color appeared greener and less yellow ( P ≤ 0.009) by prime hulls and less yellow ( P = 0.001) by California type hulls. For body composition, prime hulls and California type hulls at both levels lowered ( P ≤ 0.017) body fat, and California type hulls at 7.5% decreased ( P = 0.001) lean weight. In summary, inclusion of prime hulls and California type hulls up to 15% had no negative effect on egg production and egg quality while reduced the body fat percentage and mass.

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