Transgenic, high-protein sorghums display promise in poultry diets in an initial comparison

Shemil P Macelline; Ian D Godwin; Guoquan Liu; Jemma Restall; David I Cantor; Bernard V McInerney; Mehdi Toghyani; Peter V Chrystal; Peter H Selle; Sonia Yun Liu

doi:10.1016/j.psj.2024.103698

Transgenic, high-protein sorghums display promise in poultry diets in an initial comparison

Poult Sci. 2024 Mar 30;103(6):103698. doi: 10.1016/j.psj.2024.103698. Online ahead of print.

Authors

Affiliations

¹ School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, New South Wales 2006; Poultry Research Foundation, The University of Sydney, Camden, New South Wales 2570, Australia.
² Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia.
³ Australian Proteome Analysis Facility, Macquarie University, Sydney, New South Wales, Australia.
⁴ Aviagen Inc. Goulburn, New South Wales 2580, Australia.
⁵ Poultry Research Foundation, The University of Sydney, Camden, New South Wales 2570, Australia; Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales 2006, Australia.
⁶ School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, New South Wales 2006. Electronic address: sonia.liu@sydney.edu.au.

Abstract

This study aimed to compare the inclusion of transgenic sorghums against commercially available sorghums on growth performance in broiler chickens. Isonitrogenous and isoenergetic diets were offered to a total 288 male Ross 308 broiler chickens from 14 to 35 d posthatch. Three dietary treatments were diets based on transgenic sorghums with a mean protein content of 154.7 g/kg and 5 treatments were based on commercially available sorghum hybrids with a mean protein content of 90.6 g/kg. Soybean meal inclusions in the commercial sorghum diets averaged 215 g/kg, which was reduced to 171 g/kg in the transgenic sorghum diets because of the higher protein contents. Overall growth performance was highly satisfactory, and commercial sorghums supported 2.55% (2,330 vs. 2,272 g/bird; P = 0.010) more weight gains and 2.74% (2,929 vs. 2,851 g/bird; P = 0.012) higher feed intakes; however, the transgenic sorghums supported a fractionally better FCR (1.255 vs 1.257; P = 0.826). There were no statistical differences in apparent jejunal and ileal starch and protein (N) digestibility coefficients between treatments. The transgenic sorghum diets generated slightly, but significantly, higher AME:GE ratios and AMEn, but the commercial sorghum diets generated 6.33% (235 vs. 221 g/kg; P < 0.001) greater breast meat yields. Apparent ileal digestibility coefficients of 16 amino acids averaged 0.839 and 0.832 for transgenic and commercial sorghum-based diets, respectively, without any significant differences in individual amino acids. This outcome suggests amino acid digestibilities of the transgenic sorghums may be inherently higher than commercial hybrid sorghums as the 25.7% higher average soybean meal inclusions would have advantaged amino acid digestibilities in commercial sorghum diets. The possibility that the digestibilities of amino acids in the kafirin component of transgenic sorghums was enhanced by modifications to the structure of kafirin protein bodies is discussed. In conclusion, transgenic sorghums with higher protein concentrations led to 20.5% reduction of soybean meal inclusions in broiler diets, and this change did not compromise feed conversion efficiency compared to standard commercial hybrid sorghums.

Keywords: broiler chicken; kafirin; sorghum; transgenic.