Effects of rumen-protected methionine on milk production of dairy goats

Twelve lactating Saanen goats were fed with a total mixed ration (forage: concentrate 67:33) and directly supplemented (administered orally) with 0, 2.5 and 5.0g/head/day of rumen-protected methionine (RPM) for 30d. Body weight was not affected by RPM. There were quadratic (P<0.05) effects on milk yield, fact-corrected milk, energy-corrected milk and milk protein as RPM increased; thus, the highest values of milk yield, fact-corrected milk, energy-corrected milk and milk protein were observed with 2.5g of RPM. Percentage of fat increased quadratically (P<0.05) as RPM doses increased, while fat expressed as grams per day was not affected with RPM. It was possible to improve milk production and milk protein in dairy goats with a daily supplemented dose of 2.5g of RPM. Further studies with more animals should be developed.