Nutritional evaluation of pastures with dairy cattle.

Summary Three digestion trials were conducted during the summer months at three different periods of permanent pasture (oats, rye grass, clovers, and volunteer grasses) growth from May through August, 1959. A combination of internal (lignin) and external (Cr 2 O 3 ) indicators was used to determine digestibility and intake of grazed herbage as the only source of forage in the total ration of milking cows. Forage samples were collected regularly throughout the experimental period. Milk weights, pasture scores (quantity and quality), and ambient temperatures were recorded daily. Milk production adjusted for expected decline in lactation was significantly higher (P  Regression analyses indicated that pasture quality score was the only significant variable in predicting milk production among the variables studied. Thus, a simple method of pasture evaluation appears to be of benefit in determining when to commence supplemental summer forage feeding to lactating cows grazing permanent pasture as the sole source of forage.