Comprehensive Study of Sperm Proteins and Metabolites\nPotentially Associated with Higher Fertility of Zebu Cattle (Bos indicus) in Tropical Areas

Crossbreeding of zebu cattle (Bos indicus) with European breeds (Bos taurus) producing crossbred cattle was performed to overcome the low growth\nrates and milk production of indigenous tropical cattle breeds. However,\nzebu cattle fertility is higher than those of crossbred cattle and\nEuropean breeds under warm conditions. Combination study of proteomics\nand metabolomics toward Malaysian indigenous breed Kedah × Kelantan-KK\n(B. indicus) and crossbreed Mafriwal-M\n(B. taurus × B.\nindicus) to understand physiological reasons for higher\nthermotolerance and fertility in Zebu cattle sperm. 161 regulated\nmetabolites and 96 regulated proteins in KK and M (<i>p</i> < 0.05) showed more efficient carbohydrate and energy metabolism,\nhigher integrity of the DNA and plasma membrane, a lower level of\nreactive oxygen species, and higher levels of phospholipids, which\nconfirmed higher sperm plasma membrane integrity in KK. A stronger\nantioxidant system and lower polyunsaturated fatty acids help KK sperm\ncope with oxidative stress under warm conditions. The higher abundance\nof flagella structural proteins in KK provides a stronger structure\nthat supports sperm motility. Abnormality of flagella, plasma membrane\ndisruption, and DNA fragmentation were higher in M. These findings\nprovide selective molecular markers for developing high-producing\nand more thermotolerant cattle breeds in tropical areas (197 words)