Study on Reproductive Traits of Barred Plymouth Rock and White Plymouth Rock Parent Stock (Female Breeders) in the Humid Zone of Nigeria

The study was carried out to assess the reproductive abilities of White Plymouth Rock (WPR) and Barred Plymouth Rock (BPR) parent stock (layer breeders) reared under similar housing (deep litter), management and agro-climatic conditions. A total of 1,763,322 and 1,732,966 fertilized eggs were produced by WPR and BPR, respectively, during the observed period which lasted four years (2002-2005). Normal chicks produced were WPR: 1,205,031 (68%) and BPR: 1,310,177 (76%). The analyzed data showed that breed has no significant effect on fertility. WPR and BPR genotypes recorded 3.84±0.036eggs and 3.80±0.037eggs/hen/week, respectively and were similar. However, batch has significant (P<0.01) effect on the number of fertile eggs produced regardless of the breeds’ performance. Batch 1 recorded the highest mean values (4.03±0.045eggs), intermediate in batch 2 (3.8±0.045eggs) and batch 3 (3.62±0.044eggs/batch/week), being the lowest. As regards hatchability, there was significant (P<0.01) effect of breed on this reproductive trait in layer breeders. BPR genotype recorded the highest mean values (2.83±0.043chicks) and was superior to WPR breed which had 2.54±0.042chicks/hen/week. Similarly, batch has significant (P<0.01) effect on hatchability. Batch 1 recorded the highest mean values (2.88±0.053chicks), intermediate in batch 2 (2.67±0.053chicks) and batch 3 (2.50±0.052 chicks/batch/week), being the lowest. It was revealed in this study that BPR genotype was superior in terms of hatchability rate to WPR. This implies that the former produced and supplied more day-old chicks to the market than the latter and therefore, appeared productive and could be recommended to hatchery operators as the breed of choice in this zone. There was no significant breed x batch interaction effect on fertility and hatchability. It was indicated in this study that both genetic and non-genetic factors affected the reproductive traits of parent stock in Nigeria. It is hereby suggested that to meet the increasing demand for commercial chicks in this country, favourable environment, adequate nutrition and a more productive breed of parent stock should be provided.