Variation in Nutritional Value of Sorghum Hybrids with Contrasting Seed Weight Characteristics and Comparisons with Maize in Broiler Chicks

Abstract

Sorghum [Sorghum bicolor (L.) Moench] hybrids with high seed weight often have higher protein and fat contents. Experiments were conducted to compare the feeding value of grain sorghum hybrids contrasting in seed weight and composition with conventional hybrid maize (Zea mays L.). Feeding assays were conducted using broiler chicks to determine the metabolizable energy (ME) content of the various cereal grains. Eight sorghum hybrids were produced from crosses of two seed parents with two normal‐seeded and two large‐seeded male parent lines. The seed parent lines were ASA3042 and AWheatland. The normal‐seeded male parents were RTx2737 and RTx435, and the large‐seeded parents were KS115 and Eastin‐1. The eight sorghum hybrids and a hybrid maize check were produced under dryland conditions at Manhattan and Ottawa, KS, in 2000 and at Manhattan and Belleville, KS, in 2001. Feeding trials were conducted in the spring of 2001 and 2002. Each trial consisted of a reference diet and the hybrid maize and sorghum entries with six pens per treatment. A combined analysis across environments indicated that hybrid maize had an ME value of 3.51 Mcal kg−1 and the large‐seeded male parent, KS115, produced hybrids with ME values that averaged 3.48 Mcal kg−1 Normal‐seeded hybrids averaged 3.36 Mcal kg−1 These studies indicate that use of KS115 as a means of increasing seed weight and fat content of grain sorghum may also contribute to increased nutritional value of the grain.