Date of Graduation
Doctor of Philosophy in Poultry Science (PhD)
Nicholas B. Anthony
Michael T. Kidd
Second Committee Member
Sara K. Orlowski
agriculture, broilers, genetics, nutrition, sustainability, water
Water scarcity is a global reality and with the anticipated population growth, freshwater resources will be further strained to meet both human needs and agriculture applications. To ensure a water sustainable and food secure future, all aspects of agriculture must become more efficient. Two strategies were explored. The potential of improving water efficiency in broilers was examined. The first strategy was to develop a more efficient and accurate method for measuring water consumption/inputs in agriculture. To date, water measuring technology has lacked the necessary sophistication to assure accuracy and repeatability of low flow water usage.
After establishing a low flow water monitoring system, it was used to divergently select for water efficiency in broilers. This was done too not only to help determine heritability of water efficiency but to assess the direct response to selection and impact on correlated traits. From a modern random bred population, lines were selected based on water conversion ratio (WCR = water consumed/body weight gain) to create the low WCR (LWCR) and high WCR (HWCR) lines. After generation 2, the LWCR line had an overall WCR of 3.28 while the HWCR had a WCR of 3.46. Body weights appeared to remain similar between the lines with a slight improvement in feed conversion ratio observed in the LWCR line. Continued selection for WCR will provide further understanding of the heritability of WCR and the correlated response to selection on growth and efficiency related traits.
A subsequent study utilized the low flow water monitoring system to evaluate the WCR of four contemporary broiler strains. In addition to live performance measurements, carcass traits at two market ages (day 43 and 56) were evaluated. Differences in WI and WCR were observed. WCR ranged from 2.813 to 2.887 at 42 days and 3.230 to 3.379 at a market age of 56 days, respectively. Per bird WI ranged from 8.563 to 9.892 at day 42 and 13.903 to 15.668 at day 56. The final section of this dissertation addresses steps that can be taken to assist in broiler breeder egg management to improve hatchability of eggs in tropical climates. Over the past 60 years, poultry has proven to be the most efficient and popular protein available, emerging as a food staple in less developed areas of the world. As a result, integrated poultry operations continue to push production in suboptimal environments lacking modern infrastructure and technology. Although the genetics/efficiencies of the modern-day broiler mask many of these shortcomings, the harsh environmental/climatic influences are less forgiving. The extreme temperatures of these climates pose new challenges within the poultry biological supply chain, that of which are overlooked by producers. Results show that implementation of data loggers can successfully track and identify temperature abuses of eggs from the nest through incubation and out in the field after chick placement. This technology can aid in the troubleshooting of temperature related challenges contributing to embryo and early chick loss.
Hiltz, J. (2021). Divergent Selection for Water Conversion Ratio in Broiler Populations. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/4318