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Ruminal digestion relative to the digestion in the remainder of the gastro-intestinal tract accounts for about 70 to 85% of the total digestion of dry matter (Annison, 1956). Phillipson (1958) showed that losses of digestible materials via absorption between the mouth and the duodenum were approximately 70% of that total. The interpretation of rumen composition and digestion data is complicated by several factors, such as dilution with materials remaining from previous feedings, inflow of saliva, variations in flow rate of the different nutrients and the time of sampling af ter feeding, (Yadava et al., 1964; Yadava and Bartley, 1964; Gray, Pilgrim and Weller, 1958a,b).The objectives of these experiments were to: 1. Determine the effects of the type of feed and the time of sampling after feeding on the concentration of selected nutrient fractions in the rumen; 2. Calculate the total digestion of the feed as determined by lignin vs.chromic oxide feed/feces ratios and; 3. Estimate the extent of total dry matter digestion accounted for by ruminal fermentation and absorption.

Data are presented from a four-year study on the seasonal variation in the blood phosphorus level of range ewes. Blood samples were collected from a group of about 40 Columbia ewes at 3 to 7 different times during the year.Seasonal trends in blood phosphorus level were fairly definite and-variations between seasons were highly significant. Highest blood phosphorus levels were found on the winter and spring ranges, while lowest levels were found at lambing time, in the late summer and fall, and on the winter feed lot. Supplemental feeding of cottonseed cake or oats on the winter range or feed lot increased the phosphorus content of the blood.Blood phosphorus was lower for ewes that had lambed than for ewes that had not yet lambed. Dry ewes had higher blood phosphorus than ewes which were pregnant or were suckling lambs. Ewes with one lamb had higher blood phosphorus than ewes with two lambs.A relationship was found between gain or loss in body weight and blood phosphorus. Ewes which were losing weight tended to have higher blood phosphorus.Blood phosphorus tended to decrease with age.No definite evidence of phosphorus deficiency was found except low blood phosphorus levels. The percentage of ewes having blood phosphorus values of 3.50 mg. or below for the various seasons were 5.30 for the fall range, 2.50 for the feed lot, 20.0 at lambing, 2.7 for the spring range and 10.0 for the summer range.

Experiments to determine the phosphorus requirement for fattening lambs have been carried out employing 675 western lambs in a series of five experiments. Lambs fed on rations containing 0.07 to 0.12 per cent phosphorus or an intake of 1.20 to 1.67 grams of phosphorus per 100 pounds live weight showed abnormally slow gains, high feed requirements, and specific symptoms of aphosphorosis such as depraved appetite, unthrifty appearance and low blood phosphorus. A level of 0.14 per cent phosphorus in the diet indicated a borderline phosphorus deficiency, which proved to be inadequate for normal growth and feed utilization. Lambs receiving rations with a phosphorus content ranging from 0.15 to 0.23 per cent were adequately supplied with phosphorus as indicated by good rate of gain, efficient feed utilization and normal blood phosphorus levels. On the basis of phosphorus intake per unit live weight, lambs receiving from 2.17 to 3.38 grams daily per 100 pounds of live weight will meet their phosphorus requirement.Although a somewhat lower phosphorus level may be adequate, due to the different conditions under which lambs are fattened, it is suggested that the optimum feed phosphorus requirement for fattening lambs be set at 2.40 grams per 100 pounds of live weight or the ration should contain on a dry basis 0.17 per cent or more phosphorus.These results indicate that a phosphorus deficiency in lambs exerts a more depressing effect on the utilization of the feed than on the appetitie.

Results from a factorial experiment involving 72 Columbia-type lambs on two different protein supplements and four levels of stilbestrol are presented. Soybean oil meal was a significantly better protein supplement than urea when urea (42% N) was fed at the rate of three % of the concentrate mixture with poor quality non-legume hay (urea furnished 41% of the nitrogen in the ration). Feeding stilbestrol produced significantly greater gains on both types of nitrogen. There were no significant differences in carcass grades or yields as a result of stilbestrol treatment. No death loss nor observable deleterious effects were attributable to the stilbestrol.

A chromatographic method for the determination of cobalt in feeds is described. The ashed sample is dissolved with HCl, filtered, and the filtrate evaporated to dryness. Perchloric acid is added and the contents evaporated to white fumes. With the addition of distilled water and nitroso R salt, the cobalt complex color is developed in the usual manner. The entire solution is passed through a perchloric acid-washed alumina column. The cobalt complex is adsorbed on the column. The excess reagent is eluted from the column with dilute HNO3. The cobalt complex is then eluted with dilute H2SO4, and determined colorimetrically.Advantages over previous methods are that copper and iron do not interfere with the cobalt determination, and larger initial samples may be ashed to give a greater concentration of cobalt in the final solution for a colorimetric determination.As determined by this method, the cobalt content of hays range from 0.047 to 0.468 p.p.m., cereal grains from 0.014 to 0.091 p.p.m., and plant protein concentrates (sunflower, cottonseed, and linseed meal) from 0.190 to 0.500 p.p.m.

Two experiments designed to study the protein requirements of pregnant ewes are reported. Six lots of twenty ewes each were included in each experiment. In the first experiment rations which contained approximately 7, 10, and 13 percent total crude protein were compared and in the second rations containing 5, 8, and 11 percent protein.No statistically significant differences were found between the various rations in fleece weight, birth weight of lambs, or weight of lambs at thirty days of age. Some trends were noted, however, in that the ewes fed the lowest levels of nitrogen tended to shear lighter fleeces and their twin lambs weighed slightly less at thirty days.The death loss of ewes was somewhat higher on the low-protein rations. The low nitrogen intake may have been a predisposing factor in a number of these deaths.Nitrogen balance experiments showed no significant differences in nitrogen retention between the three levels of nitrogen intake during early and mid gestation. In late pregnancy the ewes fed the higher levels of nitrogen retained significantly larger amounts.A highly significant correlation (r=0.69) was found to exist between nitrogen retention and digestible dry matter intake. Covariance analysis showed that, at the levels fed in these investigations, the amount of nitrogen stored was influenced more by the amount of dry matter digested than by the amount of nitrogen fed.The results obtained indicate that present recommendations with respect to amounts of crude protein for pregnant ewes may be decreased when the rations fed are adequate in other nutrients.

A rapid, simple and accurate method has been presented for the determination of the wool fiber diameter. This method makes use of the audio oscillator and a vibrascope constructed from a “2” inch permanent magnet speaker. With this apparatus, the frequency is obtained at the maximum vibration of the wool fiber. The diameter of a vibrating wool fiber then can be calculated from the following equation:Where D is the diameter of the wool fiber in microns, T is the tension in grams: d is the density of the fiber; L is the length in cm. and V is the frequency in cycles per second.This method has been found useful for evaluating the quality of individual fleeces in a selection program, designed to reduce variability in fiber diameter.

A reversal of wool pigmentation from white to black and vice versa has occurred in Hampshire sheep fed rations low in vitamins A and D.Vitamin A treatments to depleted sheep of Hampshire origin brought no response in pigmentation pattern.A reversion to original wool pigmentation was noted when vitamin D was administered to lambs previously treated with vitamin A.Sheep of Delaine-Merino × Rambouillet ancestry or Columbia-type sheep that were heterozygous for black showed no pigmentation reversal pattern.There was a difference between Hampshire lambs in their response to rations deficient in vitamins A and D.

The results of three double reversal, nitrogen balance experiments conducted with mature ewes are presented. These experiments were designed to determine the effect of methionine supplementation upon the utilization of various amounts and sources of protein.When the results of the three experiments, in which five different rations were studied, are considered the addition of DL-methionine significantly increased nitrogen retention. The supplemental methionine had considerably greater effect when added to certain rations than when added to others. Possible reasons for these differences are discussed.L-methionine intake and excretion values were determined microbiologically in two of the experiments. The results of these analyses indicated that the supplemental methionine was either completely utilized or destroyed.When fed at approximately the same level of protein intake dehydrated alfalfa had a significantly higher biological value than field peas. The data presented suggest that some factors other than the level of protein intake or amino acid make-up influenced the utilization of protein in these experiments.

The results of four experiments are presented. There were no consistent differences in lamb production from ewes fed rations approximately equal in total digestible nutrients but which varied from 6.8 to 11.0 percent total protein. There were no apparent differences in production between ewes fed linseed meal or dried skimmilk as a protein supplement to a grass hay, shelled corn ration.Pregnant Shropshire ewes averaging 135 pounds in body weight remained in positive nitrogen balance, made satisfactory gains and gave birth to thrifty lambs when fed an average of 0.10 pound digestible protein per ewe daily. No improvement in utilization of protein or production was noted from the addition of 0.10 percent DL methionine.Further work is needed relative to the protein requirements of pregnant ewes.

A total of 992 blood samples of pregnant ewes fed various kinds and amounts of protein were analyzed for oxyhemoglobin, total serum proteins, serum albumins and serum globulins. Considerable variation was found in these constituents between individual sheep and between bi-weekly samples from the same ewe.Ewes fed rations low in protein had lower serum albumins than those fed a liberal or adequate amount of protein. Low protein rations also caused a reduction in oxyhemoglobin. Serum globulins were not affected by the rations fed.When fed at an equal level of protein there were no differences in blood proteins between ewes fed linseed meal and those fed dried skim milk as the protein supplement.Ewes with high oxyhemoglobin levels tended to have high serum albumins and low serum globulins. In these experiments serum globulins predominated over serum albumins. The oxyhemoglobin, total serum protein and serum globulin levels of individual ewes were highly correlated between years.

Six wethers were fed 1500 gm./day of pelleted alfalfa. The rate of passage of Cr2O3incorporated as a component of paper and as a powder in rations was determined. Chromic oxide “powder” was excreted significantly faster than “paper”.The wethers were put on a 10-day digestion trial, and coefficients obtained by the conventional method agreed with those obtained by the ratio technique using Cr2O3“paper”. Low recovery of the “powder” was noticed in all runs. The levels of Cr2O3paper and crude fiber in the feces were correlated significantly.Following the digestibility trial the wethers were slaughtered 10 to 12 hours after the last feeding and the alimentary tract contents removed in 13 sections. The digesta from each section was analyzed for dry matter, ash, Cr2O3, calcium, phosphorus, protein, crude fiber and lignin. Indigestibilities of these feed constituents were calculated using Cr2O3“paper”, Cr2O3“powder”, and lignin techniques. Chromic oxide apparently was passed out of the rumen faster than lignin or the bulk of the dry matter. The rate of flow of calcium and Cr2O3appeared to be very similar. Indigestibilities and levels of lignin and crude fiber showed a high degree of association of these constitutents in their rate of flow through the tract. The concentrations of phosphorus did not follow those of calcium.