| Popis: |
ABSTRACT: A total of 216 Cobb 500 broiler breeder hens were randomly distributed across 2 dietary treatments with 0 or 1% spray-dried plasma (SDP) resulting in 27 replications/treatment and 4 birds/replication. In addition, 36 roosters were divided between the same treatments and housed, in individual pens, being each bird considered a replicate. Experimental diets were fed from 26 wk until 65 wk of age. At 29, 45, and 63 wk of age, broiler breeder hens were inseminated, and eggs were incubated. Three progeny studies were performed and hatched birds were allocated in a randomized 2 × 2 factorial design (maternal diet: with or without inclusion of 1% SDP × progeny diet: with or without the inclusion of 2% SDP from 1 to 7 d of age). After 7 d of age, all birds received the same diet until 42 d. In all trials, birds were challenged with coccidiosis vaccine at 7 d of age. Furthermore, in the second experiment, heat stress was also included for 6 h a day during the whole trial. At 42-days posthatch in the first experiment, greater FI, BW, and BWG in chicks hatched from breeders fed 1% dietary SDP was observed. This effect did not extend to the other hatches. In the second trial, a decreased FCR in broilers fed the control diet from breeder hens fed 1 % of SDP was observed, as well as an interaction between the SDP groups, since broilers supplemented with SDP and originated from breeders fed SDP showed higher BW and BWG in comparison to other groups at 42 d. In the third trial, contrary to what was observed in the first study, SDP supplementation did not affect any of the performance indexes. In the 3 studies, no differences were found in carcass characteristics. SDP did not affect hen BW, egg production, fertility, or hatch of fertile. These results suggest that providing dietary SDP to broilers has some beneficial effects on broiler chickens. |
