Complete mixed diets containing 0, 10, 15, or 20% whole cottonseed were fed to 12 cows in a 4 X 4 Latin square design. Cows were assigned to the Latin square by production status resulting in one square each for cows in early first lactation and older cows either in early or late lactation. Diets were fed for ad libitum intake, and periods were 21 days. Percentages of milk fat and total solids increased, and protein percentage decreased with cottonseed feeding. Milk casein nitrogen decreased from .387 to .375% with cottonseed feeding. Nitrogen in whey remained unchanged, and nonprotein nitrogen increased. Proportion of total nitrogen in casein and whey fractions was not altered, but proportion of nonprotein nitrogen increased. Cottonseed decreased proportions of short-chain fatty acids (carbon-6 to carbon-16) in milk and increased stearic and oleic acids. Actual yield of milk was not affected by cottonseed feeding, but yields of fat-corrected milk and milk fat were increased. Production status affected milk composition with older cows in early lactation producing milk of lower fat, total solids, and protein content compared with cows in other groups. Casein nitrogen was highest for first-lactation and lowest for older, high-producing cows. Whey nitrogen was highest for older, low-producing cows. First-lactation cows had the highest proportion of nitrogen in the casein fraction, and older, low-producing cows had the lowest. Milk fatty acid composition changed little with status.

Four lactating Holstein cows producing about 21 kg milk/day were fed complete rations containing 0, 5, 15, and 25% whole cottonseed in a 4 X 4 Latin square design. Diets were fed ad libitum. Periods were 21 days in length with total collections of feces and urine during the last 7 days of each period. Digestibilities o nitrogen, lipid, and energy increased with increasing cottonseed in the diet. There were no significant effects of cottonseed on digestibility or availability of fiber components, calcium, phosphorous, and magnesium. Cottonseed feeding did not affect dry matter intake or milk yield but did increase yields of milk fat and fat-corrected milk and decrease milk protein and solids-not-fat percentages. Synthesis of fatty acid in the mammary gland was depressed by about 50% on the 25% cottonseed diet, but transfer of dietary fat resulted in twofold increases in yields of stearic and oleic acids. Hydrogenation of cottonseed fatty acid in the rumen resulted in a fourfold increase in yield of trans oleic acid in milk fat. Samples from bulk milk tank and data collected from 55 commercial dairies showed similar changes in fatty acid composition of milk from cows fed whole cottonseed. There was no apparent effect of feeding up to 2.9 kg cottonseed dry matter per cow per day on calving interval or on incidence of displaced abomasum, ketosis, milk, fever, or retained placenta.

No abstract

Official methods were used to analyze composite samples of milk collected during the first 15 wk of lactation from 21 Holstein cows fed a milled ration containing 0 (basal), 15% (medium, or 30% (high) protected-tallow supplement (seven cows per treatment). Protein fractions and amino acid composition of the total proteins were determined from samples of individual milking. Melting characteristics of pooled samples were determined by nuclear magnetic resonance. Milk yield was similar for the three treatments, but percent fat and fat yield were higher for cows fed protected tallow. Percentages and yields of protein and solids-not-fat were decreased on the protected tallow treatments, especially for high tallow. The decrease in protein was in the casein fraction. Amino acid composition of the total proteins was similar for the three treatments. Feeding protected tallow caused decreases in all fatty acids except 4:0, 16:1, 18:0, and 18:1 which increased. Nuclear magnetic resonance indicated that butter from the basal group would be harder than that from cows fed protected tallow.

1. Results are reported from two experiments in a series to determine the optimal amount of meal to be fed in conjunction with unrestricted whey for fattening pigs.2. In both experiments, one carried out during the summer and the other during the winter season, the same four treatments were given. The control pigs received meal ad. lib up to a maximum of 6½ lb./ head daily. Pigs on the other three treatments received whey ad lib., and either 3 lb., or 3 lb. reduced at two different stages to 2 lb. of meal per head daily. There were ten pens of nine pigs on each treatment, involving a total of 360 pigs. Comprehensive carcass measurements were made on all pigs.3. The data obtained showed that satisfactory results could be obtained by feeding a daily allowance of 3 lb./pig of a proprietary sow and weaner meal throughout the fattening period, in conjunction with unrestricted whey. Where the utilization of as much whey and as little meal as possible was required, it was shown that a reduction from 3 to 2 lb. meal/pig/day by the 13th week of life could be made without adverse effects, apart from an increase of approximately 12 days in the time taken to reach bacon weights.4. Carcass grading results of all whey-fed pigs were reasonably satisfactory, but both the carcass grading and general performance of the control animals was not good. Possible reasons for this were discussed.5. Data concerning the pattern of food consumption over 14-day periods throughout the experiments were presented. Pigs given 3 lb. of meal/day throughout, or 3 lb. reduced to 2 lb./day, consumed up to approximately 3¼–3½ or 3¾–4 gal. of whey/day respectively.