Corn or wheat-based diet to manipulate lipid content in early embryos of Jersey cows.

ABSTRACT

Numerous field observations and previous reports have described a breed effect on embryonic survival to cryopreservation. Embryos collected from Jersey cows show a poor survival rate compared to Holstein embryos due to their rich intracellular lipid content. Less well documented in the scientific literature, but also reported from field observations, it was proposed that survival rates can be improved by removing corn from the feedstuff. This project was aimed to test whether corn replacement would modify intracellular lipid content in Jersey cow embryos. Non-lactating purebred Jersey cows were fed with an isoenergetic diet supplemented with either corn or wheat. Embryos were collected in vivo following ovarian stimulation and insemination. Results show only marginal impact on blood lipids. Overall, embryos were morphologically indistinguishable. Some lipids known to be associated with lower cryotolerance were significantly impacted by the treatment namely triacylglycerol, sphingomyelin and phosphatidylcholine. Corn supplementation significantly diminished mitochondrial activity in blastomeres. These treatment effects suggest an indirect mechanism potentially impacting embryo quality through mitochondrial dysfunction rather than direct lipid uptake.