Sutisa Khempaka

Effects of cassava pulp fermented with Aspergillus oryzae as a feed ingredient substitution in laying hen diets

SUMMARY This study was conducted to investigate the effects of using cassava pulp fermented with Aspergillus oryzae as feed ingredient substitution to improve nutritive values in laying hen diets. In experiment I, a total of 48 laying hens (Isa Brown) was placed in individual cages to measure nutrient digestibility for 10 days. Six dietary treatments were control and fermented cassava pulp (FCP)‐substituted diets at 8, 16, 24, 32, or 40%, respectively. The results showed that FCP can be used in laying hen diets up to 32% without showing negative effects on nutrient digestibility or retention. In experiment II, a total of 192 laying hens was randomly distributed to 4 dietary treatments: control and FCP substitution diets at 16, 24, or 32% through 8 weeks. All FCP substitution levels had no effect on feed intake or egg weight. Egg production was significantly decreased when FCP was used at levels of 32%. Feed conversion ratio, egg mass, and protein efficiency ratio decreased linearly (P ≤ 0.05) as FCP was increased in the diets. However, FCP had no detrimental effect on egg quality, except for the egg yolk color being linearly decreased with increasing the pulp in diets (P ≤ 0.05). The biochemistry profiles revealed FCP had no effect on the enzyme activities of aspartate aminotransferase or alanine aminotransferase, cholesterol, or total immunoglobulin in laying hens. In conclusion, FCP can be used in laying hen diets up to 24% without showing negative effects on nutrient digestibility, egg production, egg quality, or blood biochemistry.

Linseed oil or tuna oil supplementation in slow-growing chicken diets: Can their meat reach the threshold of a “high in n-3 polyunsaturated fatty acids” product?

SUMMARY A strategy for enriching the meat of slow‐growing chickens with n‐3 fatty acids from tuna oil (TO) or linseed oil (LO) is proposed. The effects of TO or LO supplementation on the growth performance of the chickens and the quality, cholesterol content, and fatty acid composition of the meat were examined. A total of 560 21‐day‐old mixed‐sex Thai indigenous crossbred chickens was assigned to a completely randomized design with 7 treatment diets and 4 replicates. The control group consumed a basal diet of corn‐soybean meal supplemented with rice bran oil (RBO; 6%). In the experimental diets, RBO was replaced with 2, 4, or 6% TO (TO2, TO4, and TO6) or with 2, 4, or 6% LO (LO2, LO4, and LO6). All groups received 6% added oil. The TO6 diet lowered the final BW and FCR. The boiling loss of breast meat was highest in LO6 and differed from the losses in the control and TO2 groups. Meat from TO4 and LO6 yielded the lowest n‐6/n‐3 ratio. The alpha‐linolenic acid (ALA) content linearly increased across the LO group. The n‐3 fatty acid accumulation in the slow‐growing chickens was nutritionally valuable for human consumption. Breast meat from TO2 and TO4 provided >250 mg docosahexaenoic acid (DHA) per 100 g fresh meat. Thigh meat from at least 2% TO or 6% LO contained >80 mg (eicosapentaenoic acid + DHA)/100 g meat and 600 mg ALA/100 g meat, respectively, reaching the “high in n‐3 polyunsaturated fatty acids” threshold in dietary recommendations.