Climatic Conditions Influence the Nutritive Value of Wheat as a Feedstuff for Broiler Chickens

Abstract

Forty wheat samples of ten wheat cultivars harvested from optimal or late sowings in 2019 and 2020 were evaluated for nutrient composition. This included crude protein, starch, amino acids, minerals, phytate-phosphorus and non-starch polysaccharides (NSP). The objective was to investigate the impact of high temperature on wheat grain quality as a feedstuff for broiler chickens. Growth performance and economic impact of such change were predicted by the Emmans, Fisher and Gous broiler growth model. On average, 2019 was 1 °C hotter than 2020 during the growing season. The 2019 wheat had higher concentrations of crude protein, phytate-P, Calcium and total Phosphorus. In 2019, on average, late sowing increased protein concentration by 14.2 %, decreased starch concentration from 72.58 to 70.80 g/100 g, and increased total NSP (69.3 versus 73.9 g/kg). Unlike the 2019 harvest, the late sowing in 2020 was much cooler and no impact on crude protein concentrations was observed except for Zanzibar (17.05 versus 14.12 g/100g). The 2019 samples also 26 had higher concentrations of all 16 assessed amino acids (P < 0.001). The largest difference (19.2%) 27 was in lysine and the smallest difference (11.1%) in proline. In comparison to 2020, it was predicted 28 35 days post-hatch that broiler diets formulated from 2019 wheat samples could potentially ad-29 vantage feed conversion ratio (FCR) by 4 points or save feed cost by $0.03/kg live weight.