Feeding oleamide to lactating Jersey cows 1. Effects on lactation performance and milk fatty acid composition

Oleamide was previously reported to resist ruminal biohydrogenation and ele vate milk oleic acid concentration when fed to lactating Holstein cows. To determine if Jersey cows responded similarly to oleamide, four lactating Je rsey cows (mean 417 kg of body weight and 64 days in milk) were fed four di ets in a 4 x 4 Latin square with 2-wk periods. Diets were total mixed ratio n containing 47% corn silage and 53% concentrate (dry matter basis) and wer e supplemented with no added fat (control), or with 3.5% added fat from eit her high-oleic canola oil, a commercial source of oleamide, or oleamide syn thesized from oleic acid and urea. The canola oil supplement had no effect on milk yield or composition. Compared to canola oil, the oleamide suppleme nts reduced milk yield, dry matter intake, and milk fat and protein content s. Milk oleic acid concentration increased from 17.4% of total fatty acids far the control diet to 22.1% for the canola oil diet. Bath oleamides furth er increased milk oleic acid to 30.0 and 27.1% of total fatty acids for the commercial and synthesized oleamides, respectively. Milk palmitic acid was reduced and stearic acid was increased by all fat supplements but more so by the oleamides than by the canola oil. Consistent with previous reports t hat fatty acyl amides resist ruminal biohydrogenation, feeding oleamide to Jersey cows in this study increased milk oleic acid concentration but had n egative effects on feed intake and milk yield.