Biochemical and protein nutritional potential of mulberry (Morus alba L.) leaf: partial substitution improves the nutrition of conventional protein

Abstract BACKGROUND With the requirements of environmental, cost and economic sustainability, new sources of alternative proteins in the livestock industry are receiving increasing attention. Mulberry ( Morus alba L.) leaves are a unique feed resource because of their high protein content and large availability. Therefore, mining sustainable protein suitable for the animal husbandry industry in sericulture resources could achieve a win–win situation. RESULTS The protein content in mulberry leaves is 232.10–386.16 g kg −1 , and the mean value of crude fat content is 43.76 ± 8.48 g kg −1 , which has the advantages of protein content and energy. In addition, the average content of phytic acid in mulberry leaves is only 1.88 ± 0.56 g kg −1 , which means that it is not inhibited in terms of nutrient absorption. Meanwhile, the digestibility of protein was Bean pulp > Sample 8 ≈ Alfalfa ≈ Sample 13 ≈ Cottonseed meal > Fish meal, and the β ‐turn and particle size of mulberry leaf protein are more conducive to digestion in vitro . Furthermore, the protein of Sample 13 had the richest essential amino acids (252.00 g kg −1 ) and the highest essential amino acid index (EAAI), which was superior to conventional feed protein. In addition, the partial substitution of mulberry leaf protein (15%) significantly increased the EAAI value of conventional feed protein. However, to balance nutrition, it is necessary to combine mulberry leaf protein with other proteins to further broaden its application field. CONCLUSION Mulberry leaves are a new source of feed protein, which helps to alleviate the two major problems of mulberry resource surplus and feed protein resource shortage. © 2023 Society of Chemical Industry.