Coastal Bermudagrass Hay and Silage at Two Stages of Maturity, Fed with Two Concentrate Levels to Lactating Cows

SU]~ARYCoastal Bermndagrass (Cynodon dactylon), harvested at prehead and fullhead stages as hay and silage, was fed with two levels of concentrates to 48 cows in a 2 ~ factorial trial Direct-cut silage, preserved with 100 lb of ground corn per ton, was slightly more valuable for milk production than artificially dried hay.Cows fed prehead-stage forage produced 2 lb more milk per day with a higher protein content than those fed Coastal Bermud~grass cut in the full-head stage.Cows given grain at the rate of 1 to 2 lb of FCM produced 4 lb more milk per day of a higher SNF and protein percentage, than those fed at the 1:4 ratio.Milk fat content was not affected by any of the treatments.Forage dry matter consumption was low, with an average of ].48 lb per hundredweight of body weight per day.Cows fed hay, prehead-stage forage, and the lower level of concentrates ate more than those fed silage, more mature forage, and the higher level of concentrates, respectively (P < 0.01).The depressing effect of high concentrates on forage consumption was less with silage than with hay (P < 0.05).Coastal Bermudagrass is a ve~T important forage crop in the Southeast.It is either immune or resistant to the many diseases and insects which attack most other improved forages and is quite tolerant to heat and drouth.Annual yields of over 10 T of dry matter per acre have been reported (4).Coastal Bermudagrass is most commonly harvested as field-cured hay, but frequent periods of rain and high humidity make this a hazardous practice.On the other hand, the low moisture content of the growing plant suggests its use as direct-cut silage.McCormick et al. (10) found Coastal silage essentially equal to Coastal hay for fattening steers.However, Johnson et al. (7) found it inferior to corn silage for milk production.It is well known that stage of maturity has an important effect upon the nutritional value of many forages.However, since Coastal Bermudagrass is a sterile hybrid, changes during the maturing process may be less nmrked.Studies of the effect of age of this forage upon milk production are particularly meager (13).Very early harvesting tends to reduce yields and increase harvesting costs.Since Coastal Bermudagrass hay does not compare favorably with corn silage and alfalfa hay for lactating cows (2, 7, 8), the possibility