Effect of dietary supplementation of spray-dried plasma on performance and semen quality in aging broiler breeders

A total of 216 Cobb 500 broiler breeder hens were randomly distributed across two treatments consisting of diets supplemented with 0 or 1% spray-dried plasma (SDP), resulting in 27 replications per treatment and four birds per pen. In addition, 36 roosters, housed in individual pens, were allocated to the same treatments, with each bird considered a replicate, in order to assess the influence of SDP on semen and hatching characteristics. The experimental diets were fed from 26 weeks until the conclusion of the study, at 65 weeks of age. Semen quality, embryonic mortality and quality of newly hatched chicks were evaluated at 29, 45, and 63 weeks. Hens were inseminated with fresh semen, and eggs were incubated following standard procedures. Semen from 63-week-old roosters had higher sperm concentration than other age groups, while 29-week-old rooster semen exhibited higher progressive motility than semen from older roosters (P < 0.001). The 45-week-old roosters had the lowest values for the analyzed semen quality parameters (average path velocity, straight-line velocity and curvilinear velocity). Additionally, sperm from 45-week-old roosters, regardless of SDP supplementation, had fewer total morphological defects than 63-week-old roosters. However, 1% SDP in the diet reduced total sperm cell defects at 63 weeks of age, as well as total sperm head and tail defects (P < 0.05) compared to unsupplemented birds. Dietary SDP reduced late embryonic death in 63-week-old breeders (P < 0.05). The results demonstrate that 1% SDP in breeder diets reduced late embryonic mortality and sperm cell defects, mainly in aged birds, enhancing the reproductive performance of broiler breeders.

Keywords:
breeder age; chick quality; embryonic mortality; sperm cell kinetics; sperm morphology