Effects of oral doses of corn oil and other factors on preweaning survival and growth of piglets.

Piglets were provided supplemental energy as oral doses of corn oil to find whether such treatment might improve survival or weight gains. A total of 1,840 piglets from 182 litters was used. Piglets were allotted to dosed and control treatments within litter on the basis of body weight. Dosed piglets received a total of 8 ml of corn oil in four doses during the first 48 h postpartum. The survival rate to weaning was high and not affected (P greater than .10) by the corn oil doses. Deaths of piglets low in birth weight were delayed by the fat doses, suggesting some utilization. The fat doses did not affect piglet weight gain. Factors affecting preweaning survival and growth of piglets were also evaluated using data from the same piglets. Specific factors investigated were sex, parity of dam, birth weight, litter size and the mean and standard deviation of piglet birth weights within litters. Male piglets were heavier at birth than females, but there was no sex effect on weight at 7 d or at weaning. Small males were less likely to survive to 3 d than were small females. Litters from primiparous sows were smaller at birth and weaning, but had lower percentages of stillbirths and of preweaning deaths than did those from multiparous sows. Piglets from primiparous sows were more uniform in birth weight. Piglets that were heavier at birth grew faster and were more likely to survive. Litter size affected growth but not survival of piglets. A heavier average birth weight in the litter reduced slightly the growth rate of individual piglets. An increase in variability of piglet birth weight within a litter was associated with an increase of the percentages of stillbirths and of preweaning mortality. A few litters accounted for a major portion of the mortality. Much of the variation in piglet mortality and growth was not explained by factors considered.

Blood plasma lipoprotein and tissue cholesterol of calves fed soybean oil, corn oil, vegetable shortening or tallow.

The objective of this study was to determine cholesterol content of blood plasma, blood plasma lipoproteins and tissues of calves fed fats of differing compositions. Groups of 2-week-old calves were fed one of the following fats in a reconstituted milk formula: soybean oil, corn oil, vegetable shortening or tallow. The diets contained no dry feed or added cholesterol. Blood plasma cholesterol concentrations increased with time for all groups. After 15 weeks, cholesterol concentrations were greater in the blood, liver and fat of the groups fed soybean oil and corn oil than in those of the groups fed vegetable shortening and tallow. Low density lipoprotein was identified as the carrier of the increased amounts of cholesterol noted in the blood.

Effect of type of dietary fat on plasma and tissue cholesterol of calves.

Two experiments were conducted to examine the effects of liquid milk diets with varying proportions of beef tallow (T) and soybean oil (SBO), with and without dry feed, on cholesterol concentrations in blood and other tissues of nonruminating calves. In experiment 1, 4--10-day-old male Holstein calves were fed for 15 weeks a reconstituted milk containing 9% ot 12% dried skim milk and 2% SBO, 2% T or 3.5% T. Plasma cholesterol and cholesterol content (% of dry matter) of muscle, liver, omental fat and perirenal fat were greater (P less than 0.05) for calves fed the 2% SBO diet. No significant differences were observed in cholesterol concentrations of the aorta, coronary arteries, brain or spleen. Experiment 2 used 4--10-day-old male Holstein calves to study the effect of 2% fat diets formulated in ratios of SBO 2/3:T 1/3 and SBO 1/3:T 2/3 and to observe the effect of dry feed added to 2% T and 2% SBO diets. Tallow and SBO fed in weighted combinations affected plasma and tissue cholesterol concentrations like the predominant fat fed alone. The greatest increases in plasma and tissue cholesterol concentrations occurred in calves fed SBO diets. Dry feed supplementation decreased body cholesterol concentrations of calves fed either fat. Body weight gain of calves fed SBO was less in both experiments.