G. Richard Jansen

Measurement of Milk Yield in the Lactating Rat from Pup Weight and Weight Gain

A new method was developed that enables milk yield to be estimated from pup weight and pup weight gain in well-nourished rats. Daily milk yield, body weight, and daily weight gain were measured over 4–5-day periods in 38 suckling pups aged 3–13 days post-partum. Each 24-h period was divided into conA new method was developed that enables milk yield to be estimated from pup weight and pup weight gain in well-nourished rats. Daily milk yield, body weight, and daily weight gain were measured over 4–5-day periods in 38 suckling pups aged 3–13 days post-partum. Each 24-h period was divided into consecutive 6-h cycles, during which dams and pups were separated for 4 h and then reunited for 2-h suckling intervals. Daily milk yield per pup was calculated from pup weight gain during the four suckling intervals for each 24-h period, and corrected for insensible weight loss of the pups. The following equation, relating pup milk yield to pup weight and weight gain, was obtained by stepwise forward multiple regression analysis: yield = 0.0322 + 0.0667 (weight) + 0.877 (gain); where yield is daily yield per pup (g/pup/day), weight is pup weight (g), and gain is pup weight gain per day (g/day) (n = 174; F = 552.3; p < 0.001; r2 = 0.866). Per litter milk yield can be obtained by multiplying per pup yield by litter size. Using this equation, dams fed a stock diet and nursing eight pups were estimated to have produced 29.5 ml of milk on day 10 of lactation. This value is similar to yields measured by more laborious methods. SEs of yield estimates calculated with this method represent 1–3% of predicted yield values. The new method gives useful estimates of rat milk yield during the first 2 weeks of lactation from measurements that are more easily obtained than is the case with other methods.

Effect of dietary protein and environmental factors on lactation performance in rats

The effects of dietary protein and environmental conditions on lactation performance in rats were evaluated. Female rats were fed from conception until day 9 of lactation diets containing 21% wheat protein (21W), 21% casein + methionine (21CM) or 11% casein + methionine (11CM). At parturition, dams were kept in their normal environment (20 degrees C) or were exposed to crowded conditions or an elevated ambient temperature (30 degrees C). Feeding poor-quality protein (21W) or a lower amount of high-quality protein (11CM) reduced day 8 pup weights and average daily gains (ADG). Pup ADGs nursed by crowded dams fed either 11CM or 21CM were greater than those of pups nursed by noncrowded dams. Pup ADGs were reduced by heat exposure in dams fed 21CM but not in pups raised by dams fed diets reduced either in protein quality (21W) or protein quantity (11CM). Thus lactation performance was not further reduced by heat exposure in dams fed poor-quality wheat protein in spite of reduced food consumption and increasing lactation weight loss in these dams. The study indicates that lactating rats have considerable ability to raise their litters under potentially adverse conditions.

Centrally processed weaning foods for use in developing countries

Abstract Many approaches are needed to improve child survival and growth in developing countries. Among these are improved sanitation, breast‐feeding promotion, immunizations, diarrheal disease control, and the provision of safe and nutritious weaning foods. This review considers weaning food developments in the context of aggregate data on changes in the nutrition situation in developing countries. Infant and child mortality and growth data are reviewed. These data reveal that progress has been made in many regions of the developing world in reducing infant and child mortality over the last 20 years. Less success is apparent in reducing the prevalence of linear growth retardation of preschool children. The importance of breast‐feeding and improved sanitary practices is stressed. This review is focused on the important role weaning foods can play in addition to other cultural and health inputs in improving growth and child survival in the developing world. Following a brief introduction to the weaning per...

A nutrient approach in the fifth grade

Summary A nutrition education unit utilizing a nutrient approach was tested in fifth-grade classes. The effectiveness of the unit was evaluated by measuring scores on a test of nutrition knowledge administered before and after the unit, and by teacher and student comments. Analysis of the results demonstrated a significant improvement in test scores for all groups exposed to the nutrition unit. The increases in scores were considered attributable to the nutrition unit (p .05). Participating teachers were enthusiastic about the nature of the materials developed and the interest the unit evoked in students. Students made comments that demonstrated they found the unit interesting and enjoyable. Post test responses to student interest questions suggested that interest in nutrition had been increased by the nutrition unit. It is concluded that a nutrient approach to nutrition education utilizing a nutrient abacus can interest students and significantly improve their knowledge of basic nutrition information.

Effect of Δ22-5β-taurocholenic acid and dietary fat on hepatic cholesterol and fatty acid in hyperglycemic-obese mice

Abstract Previous work demonstrated that hyperglycemic obese mice ( obob ) fed a 1% corn oil diet accumulated cholesterol and fat in the liver when compared with nonobese littermates. The present experiment was carried out to test the hypothesis that feeding the bile acid analog Δ 22 -5β-taurocholenic acid would correct this metabolic defect. Liver total fatty acid was greatly elevated in obob mice fed 1% corn oil compared with nonobese controls (21.04 ± 1.23% versus 4.41 ± 0.27%). Incorporation of [U- 14 C]glucose into liver fatty acid was inhibited by taurocholenic acid in both obese and nonobese mice fed 1% corn oil. Taurocholenic acid reduced liver fatty acid in obob mice fed 1% corn oil to the level seen in nonobese mice (3.07 ± 0.22% versus 4.41 ± 0.27%). Cholesterol greatly accumulated in the livers of obob mice fed 1% corn oil compared with nonobese mice (0.97 ± 0.08% versus 0.28 ± 0.02%) and was reduced to normal by feeding taurocholenic acid (0.27 ± 0.05% versus 0.28 ± 0.01%) despite greatly elevating rates of incorporation of [U- 14 C]glucose into liver cholesterol. Taurocholenic acid significantly reduced liver fat in obese mice fed 40% lard (11.62 ± 1.41% versus 5.87 ± 1.03%) but had no significant effect on the percentage of liver cholesterol (0.68 ± 0.05% versus 0.56 ± 0.04%). It is suggested that the elevation of liver cholesterol in obob mice fed 1% corn oil comes about through a defect in cholesterol removal from the liver, a defect corrected by taurocholenic acid via increasing the excretion of cholesterol and bile acids in the bile by an as yet unknown mechanism. The cholesterol accumulating in obob mice fed 40% lard occurs by a different mechanism than when these mice are fed 1% corn oil since it is unaffected by taurocholenic acid.

Effect of dietary protein quality and quantity on glucose utilization in rat mammary glands during lactation

The effects on glucose metabolism in the mammary gland of feeding diets deficient in protein quality or quantity from conception through day 4 of lactation were measured. Protein sources were 13% casein plus methionine (13CM), 13% wheat gluten (13WG) or 5% casein plus methionine (5CM). Dams were sacrificed on day 20 of gestation or day 4 of lactation. Mammary slices or isolated acini were incubated with 5 mM [U-14C] glucose in the presence and absence of insulin and recovery of 14C in CO2, lipid and lactose determined. In slices on day 4 of lactation, neither dietary protein quality or quantity significantly influenced incorporation of labeled glucose into CO2, lipid or lactose. Insulin significantly increased incorporation into CO2 and lipid 15% and 17%, respectively, and reduced incorporation into lactose 16%. In acini on day 4 of lactation, reduction in protein quality (13WG vs. 13CM) reduced lipogenesis and lactose synthesis per mg DNA, but no consistent effect of insulin was observed. In both slices and acini, incorporation rates were significantly higher on day 4 of lactation than on day 20 of gestation. The almost total failure of lactation previously observed in 13WG fed dams likely is related at least in part to a reduction in glucose utilization per secretory cell as well as to reductions in mammary gland size and content of DNA, RNA and protein previously observed.

A comparison of extrahepatic lipogenesis from a small glucose meal in obob and gold thioglucose obese mice fed low- or high-fat diets with or without the addition of δ22-5β-taurocholenic acid

Extrahepatic fatty acid synthesis from a 250 mg meal of [U-(14)C]-glucose was measured in epidymal fat pads and the remaining carcass of hyperglycemic obese (obob), gold thioglucose obese, and nonobese controls under conditions of maximum and minimum lipogenesis. Also assessed was the effect of Delta(22)-5beta-taurocholenic acid, previously shown to inhibit hepatic fatty acid synthesis. Both types of obese and nonobese mice were fed for 6 weeks glucose-based diets containing either 1% corn oil or 40% lard with or without the addition of 0.05% taurocholenic acid. In mice fed 1% corn oil, incorporation of labeled glucose into carcass fatty acids was 25% greater in nonobese than obese mice of either type of obesity. On this diet incorporation of labeled glucose into epididymal fatty acids was reduced 83% in hyperglycemic obese mice compared with nonobese littermates. The corresponding reduction in lipogenesis in gold thioglucose obese mice was only 23% compared with nonobese controls. Feeding 40% lard reduced incorporation of labeled glucose into epididymal and carcass fatty acid 67 to 95% compared with mice fed 1% corn oil in both types of obese and nonobese mice whether or not taurocholenic acid had been fed. Both types of obesity or feeding 40% lard reduced lipogenesis in fat pads to a greater extent than glucose uptake by the pads with the reductions additive. Feeding taurocholenic acid reduced pad weight 30% across strain and obesity status, increased uptake of labeled glucose into epididymal fat pads and increased the percentage of the labeled glucose in the pad recovered as fatty acid in both types of obese and nonobese mice when the diet was 1% corn oil. Similarities and differences between the two obesity models are discussed.

Menu Items with Maximum Quantities of Nutrients

This chapter lists the menu items with maximum quantities of nutrients, such as proteins, sugar, fat, saturated fat, polysaturated fat, cholesterol, sodium, vitamin A, vitamin C, thiamin, riboflavin, vitamin B6, calcium, iron, zinc, potassium, and dietary fiber.

Diet Guide Nutrient Nutri-Unit Tables

This chapter illustrates diet guide nutrient nutri-unit table for various food groups such as beverages; appetizers and snack foods; breads, pastas, and grain products; breakfast items; cooking ingredients and sauces; dairy products and eggs; desserts and sweets; eating out, fast foods; fruits and fruit juices; main dishes; salads; sandwiches and soups; and vegetables.

How to Use This Guide

This chapter discusses the diet guide worksheet that is a simple tool to assist in planning and evaluating meals using the diet guide and nutrition information labels. The worksheet provides space to record the nutri-units in the foods eaten during the day. At the end of the day, the columns are totaled, and the differences between the totals and goals for each nutrient are recorded. Goals for calories, sugar, total fats, saturated fat, polyunsaturated fat, cholesterol, and sodium are considered maximum goals. Goals for protein, total carbohydrates, fiber, vitamin A, vitamin C, thiamin, riboflavin, vitamin B 6 , calcium, iron, and zinc are considered minimum goals. The chapter provides information on the kilocalorie, protein, carbohydrate, dietary fiber, sugar, total fat, saturated fat, polyunsaturated fat, cholesterol, sodium, vitamin A, vitamin C, thiamin, riboflavin, vitamin B 6 , calcium, iron, and zinc content of foods. Most foods are listed in the ready-to-eat form. Nutri-unit information is provided to the nearest whole nutri-unit for easy addition. The portion sizes required to provide the nutrients specified are listed. The chapter presents a method of diet evaluation designed to incorporate information from nutrition labels.