Synopsis Annual dry matter yields of orchardgrass and reed canarygrass over a 3‐year period ranged, from 2 tons per acre with 50 pounds of nitrogen to 4.5 tons per acre with 400 pounds of nitrogen. The protein percentage of the dry matter increased from 12 to 20. Recovery of the nitrogen applied in 1954 was 59.7, 73.5, 62.0, and 58.7% for rates of 50, 100, 200, and 400 pounds of nitrogen per acre, respectively.

First lactation milk yield and percentages of fat, solids-not-fat, and protein were analyzed to determine the possible relationships between 14 polymorphic loci and production in Holstein cows. The polymorphic systems examined were blood groups (A, B, C, F, J, L, M, S, and Z), serum transferrin, and milk proteins (beta-lactoglobulin, alpha s1-casein, beta-casein, and kappa-casein). Several statistical models were utilized. Although results differed according to the analysis conducted, in general, no system had a significant association with first lactation milk yield expressed as a herdmate deviation. Most striking were the relationships between milk protein polymorphisms and percent solids-not-fat and protein deviations; beta-casein and kappa-casein alleles had statistically significant associations with these traits. The F system was significant for percent fat deviations, whereas J x L system interactions were significant for all traits. Degree of heterozygosity over the 14 systems was positively associated with percent protein deviations.

First lactation milk yield and percentages of fat, solids-not-fat, and protein were analyzed in Guernsey cows to determine relationships of production traits to genetic markers at 16 polymorphic loci. The polymorphic systems examined were blood groups A, B, C, F, J, L, M, S, and Z; blood proteins transferrin, hemoglobin, and alkaline phosphatase; and milk proteins beta-lactoglobulin, alpha s1-casein, beta-casein, and kappa-casein. Different statistical models were utilized to evaluate direct genetic marker effects, linkage group effects, and heterozygosity effects. There were many indications of relationship with milk composition traits but for milk yield only for A system direct effects and for F system linkage effects. Pronounced associations between markers and component percentages were noted for the J, Z, and beta-lactoglobulin systems with fat percentage, for the M system with fat and solids-not-fat percentages, for the alkaline phosphatase system with solids-not-fat percentage and protein percentages, and for L and alpha s1-casein systems with protein percentage. Additionally, the interaction of beta-lactoglobulin and alpha s1-casein markers was significant for deviations of percent fat and percent solids-not-fat.

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