The Effect of Different Management Factors on the Incidence of Pendulous Crop in Commercial Turkeys

Open Access
- Author:
- Steimling, Corissa A
- Area of Honors:
- Animal Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Ralph Michael Hulet, Thesis Supervisor
William Staniar, Thesis Honors Advisor - Keywords:
- Pendulous Crop
drop crop
avian disease
turkeys
poults
poultry
brooder
turkey management - Abstract:
- The incidence of Pendulous Crop Syndrome (PC) is a long standing issue in commercial turkey production1,6. Very little has been done in recent years to monitor the occurrence of this disease, while the modern turkey (Meleagris gallopavo) has changed dramatically since the majority of pendulous crop research was completed. Two studies were conducted to evaluate the incidence of PC under different management practices. The factors in the first trial that were evaluated for their ability to induce PC lesions were ambient temperature, water space per bird, and dietary energy. The factors in the second trial that were studied in inducing PC were incubation temperature, light exposure, and feed form. In both studies there were six replicates of each combination of the three factors. Each bird showing symptoms of PC was tagged, and examined for severity of the lesion at the end of the experiment. The first trial used 2592 female Converter poults (Hybrid Turkeys), and was carried out over a period of 6 weeks (Appendix A). The poults were randomized into 4 separate rooms each with 12 equal pens (5 m2) containing 54 birds. Water intake (at all days measured) and incidence of pendulous crop (% of hen housed and % of remaining birds) were significantly greater (P < 0.01) for the birds reared on the higher temperature profile when compared to those on the control temperature profile. From these results, it was concluded that ambient temperature during brooding and/or increased water consumption increases the incidence of pendulous crops in female poults (1.56 % vs 0.31 %, P < 0.001). The second trial used 2400 straight-run Converter poults (Hybrid Turkeys), and was carried out over a period of 10 weeks (Appendix A). Turkey eggs (3600) were incubated for 28 days, wherein 2400 of the poults were collected and equally distributed into 4 separate rooms each with 12 equal pens (5 m2) containing 50 birds. Incubation and lighting (for all days measured before 28 days of age) and diet and lighting (for all days measured after 28 days of age) appeared to have the most significant effects on the incidence of PC. From these results, it was concluded that there is a significant interaction between feed form during brooding, and the particular lighting program which can influence the incidence of pendulous crops in poults (P ≤ 0.0114). The data collected from both of these studies can be used in current flock management practices to recognize and reduce factors that may induce pendulous crop. This will lead to an improved quality of life for a greater percentage of turkeys in the commercial industry, and will lead to reduced losses during production and at processing facilities.