부산대학교 도서관

Simple Summary: Lipid supplementation is a common practice in dairy cow nutrition to control heat stress, provide more energy, and alter the fatty acid profile of milk fat. Full-fat corn germ (FFCG)—a by-product from corn processing—has been indicated as an alternative lipid ingredient because of its positive effects on milk production and milk fatty acid profile. Yet, FFCG may cause ruminal disturbances that lead to milk fat depression (MFD) in cows fed fresh sugarcane and cactus cladodes, which are important forage resources for the supplementation of dairy herds in the semi-arid region. Our most recent results show that replacing fresh sugarcane with sugarcane bagasse in the diet prevents the MFD observed in cows fed FFCG. The association of FFCG, cactus cladodes, and sugarcane bagasse improves milk production and milk fat content and alters the composition of milk fat towards a healthier fatty acid profile. Hence, FFCG supplementation may be advantageous to milk producers through improved cow performance while promoting greater fat yield and fat quality for the manufacturing of dairy products with potential health benefits. We evaluated the performance, milk composition, and milk fatty acid profile of cows fed diets composed of cactus cladodes (Opuntia stricta [Haw.] Haw), sugarcane bagasse and increasing levels of full-fat corn germ (FFCG). We hypothesized that ground corn can be effectively replaced by FFCG when cactus cladodes and sugarcane bagasse are used as forage sources. The cows were randomly distributed into two 5 × 5 Latin Squares and fed five diets in which ground corn was progressively replaced with full-fat corn germ (FFCG; 0%, 25%, 50%, 75%, or 100% of substitution). Adding FFCG to the diet increased milk production and milk fat content and reduced milk protein content. Overall, FFCG reduced the proportion of saturated FAs and increased mono- and polyunsaturated FAs in milk, including CLA isomers. In addition, activity indices of stearoyl-CoA desaturase were reduced by increasing levels of FFCG. We conclude that the substitution of corn for FFCG in diets based on cactus cladodes and sugarcane bagasse positively modifies the FA profile of milk and could add commercial value to milk products (e.g., CLA-enriched milk). In addition, the milk fat response indicates that the basal diet was favorable to the rumen environment, preventing the trans-10 shift commonly associated with milk fat depression. [ABSTRACT FROM AUTHOR]