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Under the conditions of this study, the following conclusions seemed justified: 1. Cud inoculations did not improve rate of growth or efficiency of feed utilization in calves through four months of age. Consumption of hay was not materially increased by cud inoculations. 2. Thus. it is concluded that cud inoculation is of no economic value under practical calf raising conditions. 3. Calves restricted in grain feeding did consume more hay than unrestricted calves; however, the increase was not great. Efficiency of feed utilization, as measured by the pounds of T. D. N. consumed per pound of gain was essentially the same for calves on a grain:hay ratio of 1:2 (restricted grain feeding) as those on a 1:1 grain:hay ratio (unrestricted grain feeding). 4. Skeletal growth, as determined by height at withers, was adversely affected by restriction or grain in the feeding program. 5. Calves fed one pound of whole milk per ten pounds of body weight daily up to 60 days of age, and a simple grain ration made satisfactory growth when grain was fed free choice (with a four-pound daily maximum) and hay of average or better quality was fed free choice. 6. Thus, it is indicated that a substantial monetary saving in the raising of herd replacements may be affected by the use of a simple grain ration instead of high-priced commercial calf mixtures. / Master of Science

Two feeding trials were conducted to study the effects of source of concentrate and level of concentrate and roughage on milk composition; changes in certain blood and rumen constituents; and efficiency of conversion of feed protein to milk protein. Trial A (63 days) employed two groups of six cows each. The following rations were fed: 1) Control consisting of 1 lb. concentrate per 3.5 lb. milk, 40 lb. corn silage. and orchardgrass hay, ad libitum; 2) Low-roughage composed of 5 lb. orchardgrass hay, 10 lb. corn silage, and concentrates ad libitum. Trial B (70 days) employed two groups (four each) of late and three of early lactation. A control ration similar to that fed in trial A, except 48 instead of 40 lb. of corn silage, and a low-roughage ration of only 2 lb. hay and concentrates ad libitum, were fed to two groups in each stage of lactation. The remaining early lactation group received a ration comparable to the control except the corn in the concentrate was replaced by lactose. The twelve early lactation cows were subjected to a balance study at the end of the feeding trial. Intake of concentrates and milk yields on the low-roughage rations were higher in trial A than trial B. Percent milk fat and the acetate/propionate ratio of rumen fluid were decreased by low-roughage; while rumen propionate was increased. No significant differences in milk protein were observed. Milk SNF and lactose-mineral were increased on low-roughage in trial B. Feeding only 2 lb. hay daily resulted in bloat and diarrhea; while blood glucose and gamma globulin were increased. Lactose increased rumen butyrate and tended to increase milk fat percentages above the controls. Digestibilities of all dry matter components, except crude fiber, were higher on low-roughage. Cows on low-roughage digested a larger proportion of the dietary protein, but were loss efficient in the conversion of digested protein to milk protein. / M.S.

Glucose pool size (PS), pool space (PV) and clearance rate (CR) vere determined for eight first-lactation Holstein cows at three lactation stages [early (E) = 75-100 days, late (L) = 205-250 days, and dry (D) ]. A corn silage-based ration (15% CP, 22% ADP) was fed ad libitum during lactation and at maintenance during D, using 4-hr feeding intervals. Three intravenous glucose (.1 g/kg BW) injections were administered each period. Serial blood samples were collected for 40 min post-dosing. Parameters were calculated by the least squares method using natural logarithms of glucose concentration. Basal plasma glucose and insulin concentrations were 57.4, 60.1, and 62.3 mg/dl and .78, .97, and 1.24 ng/ml, respectively, for E, L, and D, respectively. PS and PV increased (P<.05) from E to D; however, when adjusted for body weight there was no difference across stages. CR decreased (P<.05) from E (2.43%/min) to D (1.71%/min) and was correlated with dry matter intake (r = .70, P<.01). Glucose-induced insulin response was greater (P<.05) during D than during lactation due to higher peak (P<.05) and lover insulin clearance (P<.05) values. Glucose parameters were determined by single injection in lactating cows fed a high-concentrate ration (16.8% CP, 13% ADF) (n=5) and a control ration (16.3% CP, 24.4% ADF) (n=4) , at 90 and 120 days postpartum. No differences due to stage or diet were observed, due to insufficient observations. Plasma glucose and insulin tended to be higher with HC-feeding and at the later stage. / Master of Science