The Effects of Varied Rates of Hay Feeding on Body Weight and Production of Lactating Dairy Cows

Many levels of roughage feeding have been reported. Mead and Goss (10) reported that cows fed concentrates alone were more subject to bloat thal~ animals fed hay plus concentrates, but otherwise the well-being of the animals was not affected. ~kt the other extrenle, Sherwood and Dean (15) observed that animals fed hay alone did not suffer harmful effects but produced less milk than cows given a supplement of grain. Smith c! al. (It,') observed that cows fed hay alone did not produce as much milk as wmlht be expected from the TDN (total digestible mltrient) evaluation of the ration. In a review, IIuffman (4) stated that the quality and productive energy content of hays are highly variable and that ha?" does not always yield production results comparable to TDN content. Huffman and Duncan (5, 6, As a result of these findings, it was postulated that unknown milk prodnetiml factors which caused increased production were present in the concentrate material.