Effects of dietary boron supplementation on broilers

Two experiments were conducted with a total of 432 broiler chicks to investigate the influence of supplementing different amounts of boron to practical corn-soybean meal diets. The birds were housed in batteries and had free access to feed and water. In Experiment 1, 144 1-day-old broiler chicks were fed a basal diet supplemented with 0, 5, 40, 80, or 120 ppm boron for 21 days. Female body weight was not influenced by the dietary treatments. However, males supplemented with 5 ppm boron were heavier and their tibias resisted more load than the control birds. Overall feed conversion was not influenced by boron. In Experiment 2, 288 1-day-old broiler chicks were fed a basal diet supplemented with 0, 60, 120, 240, or 300 ppm boron for 22 days. Male and female body weights of the 300-ppm group were lower than those of the control birds. Percentage tibia ash was highest with 300 ppm boron. No significant differences were found in intestinal tract weight (grams of intestine per 100 g body weight) among treatments. Boron concentration in the breast muscle and liver increased as dietary concentration of boron increased. Data collected in these two experiments indicated that consumption of diets containing up to 240 ppm boron from hatch to 21 days of age was not detrimental to broiler performance. Data were not conclusive on the need for supplemental boron in broiler diets based on corn and soybean meal.     

Influence of Fusarium-infected corn and F-2 on laying hens

Diets containing either Fusarium-infected corn supplying 25 and 100 p.p.m. of F-2 (zearalenone) or purified F-2 at these levels did not adversely influence the reproductive performance of laying hens. In trial 1, no deleterious effects were observed for 20- and 36-week body weights, age at first egg, egg weight, albumen height, shell deformation, fertility or hatchability when Fusarium-infected corn was fed to 20-week-old pullets for 28 days. Percent hen-day egg production of birds fed Fusarium-infected corn supplying 25 and 100 p.p.m. of F-2 was superior (P less than or equal to 0.5) to egg production of nontreated controls. In trial 2, three replications of ten adult Leghorn hens were evaluated under five dietary treatments: (1) 16.7% protein basal; (2) basal plus Fusarium-infected corn (25 p.p.m. of F-2); (3) basal plus 25 p.p.m. of (purified) F-2; (4) basal plus Fusarium-infected corn (100 p.p.m. of F-2); (5) basal plus 100 p.p.m. of (purified) F-2. Difference between dietary treatments for 14-day pre-treatment, treatment and post-treatment periods were nonsignificant for 42- and 44-week body weights, egg production, egg weights, fertility and hatchability. Body weights of chicks from hens fed F-2 diets were not significantly different from those of chicks from hens fed the basal diet.     

Growth performance, intestinal microbial populations, and serum cholesterol of broilers fed diets containing Lactobacillus cultures

A study was conducted to determine the effects of adherent Lactobacillus culture on growth performance, intestinal microbial population, and serum cholesterol level of broilers. Four dietary treatments, consisting of the basal diet (control), basal diet + 0.05, 0.10, or 0.15% Lactobacillus culture (LC), were fed to 2,000 Arbor Acres broiler chicks from 1 to 42 d of age (DOA). The chicks were randomly assigned to 40 cages (50 chicks per cage, 10 cages per diet). The experimental period was 42 d. Body weights and feed to gain ratio were measured at 21 and 42 DOA. The intestinal microbial populations and serum cholesterol levels were determined at 10, 20, 30, and 40 DOA. The results showed that body weights and feed to gain ratios were improved significantly (P < 0.05) when compared to control broilers for broilers fed diets containing 0.05 or 0.10% LC, but not 0.15% LC, at 21 and 42 DOA. Coliform counts in the cecum of birds receiving 0.05% LC at 10, 20, and 30 DOA, and 0.10% at 10 and 20 DOA were significantly lower (P < 0.05) than those of the control birds. The total aerobes, total anaerobes, lactobacilli, and streptococci in the small intestines and ceca of the control birds were not significantly different from those of the treated groups. Serum cholesterol levels were significantly lower (P < 0.05) in broilers fed the three diets containing LC at 30 DOA, and in the birds fed 0.05 or 0.10% LC at 20 DOA.     

Effect of dieldrin and calcium on the performance of adult Japanese quail (Coturnix coturnix japonica)

Two experiments were conducted to determine the effects of dieldrin and calcium on reproductive performance of quail. At 25% egg production the quail received diets containing 0,10 or 25 p.p.m. of dieldrin for 6, 28-day periods in experiment 1 and 0, 5, or 25 p.p.m. of dieldrin for 4, 28-day periods in experiment 2. Pesticide treatments were employed with diets containing 0.5% and 3.0% calcium. The results show that egg shell thickness, cracked eggs, egg production, feed consumption, egg weights, fertility, hatchability and body weights were not affected by dieldrin treatments. However, egg shell thickness, cracked eggs, egg production and hatchability were adversely affected by the lower calcium level. Female body weights were consistently heavier for the low calcium diet. Mortality increased in the presence of 10 and especially 25 p.p.m. of dieldrin. Livability of chicks from hens receiving rations with 10 and 25 p.p.m. of dieldrin was significantly lower than those fed no dieldrin. In summary, dieldrin was without effect on egg shell quality or other reproductive factors but did exert a detrimental effect on adult mortality and livability of progeny.     

Organoleptic evaluation of eggs produced by laying hens fed diets containing graded levels of flaxseed and vitamin E

Eighteen-week-old laying hens were fed diets containing 0, 10, or 20% ground flaxseed and 10 or 100 IU vitamin E/kg diet, in a factorial arrangement. When birds were 60 wk of age, eggs were collected from various treatments and used in taste panel studies. All studies involved freshly boiled eggs. In Experiment 1, four separate panels were conducted to obtain information on egg aroma, egg flavor, presence of any off-flavor, and overall acceptability of the egg. Pooled data showed a very significant difference among panelists for all attributes tested (P < 0.01) and off-flavors were detected in eggs from hens fed 10 and 20% flaxseed with 10 mg vitamin E/kg. In Experiment 2 panelists were asked to evaluate egg aroma, yolk flavor, and overall acceptability in eggs from birds fed the lowest level of vitamin E with 0 or 10% flaxseed, and birds fed 20% flaxseed and 10 or 100 mg vitamin E/kg. The highest ratings for egg aroma, yolk flavor, and overall acceptability were for the control eggs. There was a significant reduction in overall acceptability as flaxseed concentration increased (P < 0.05) and an interesting and significant (P < 0.05) decline in overall acceptability for birds fed 100 vs 10 IU vitamin E/kg diet in eggs for birds fed 20% flaxseed. In a third study, there was an indication of preference for eggs from birds not fed flaxseed, when the diet contained 10, rather than 100 IU vitamin E/kg diet. These data suggest that high (> 10%) levels of flaxseed used in the bird's diet will result in some decrease in overall egg acceptability as assessed by aroma and flavor. These effects seem to be accentuated by using high levels of vitamin E in the bird's diet.     

Effect of accelerations, additional weight load and hypokinesia on protein catabolism in the Japanese quail (Coturnix coturnix japonica)

Activities of glutamate and xanthine dehydrogenases were measured in four groups of quails (coturnix coturnix japonica): 1) hypodynamic birds which were kept in an area which made 1/4 of the control, 2) birds exposed to an increased weight load, 3) birds exposed to 3g. and 4) control birds. The experimental birds were exposed to the above treatment for 1 to 6 hours a day during 8 days. The birds were fed on a forced basis to eliminate differences in food intake. The activity of glutamate dehydrogenase was measured in the liver and that of xanthine dehydrogenase was assayed in the liver, kidneys and femoral muscle. It was found that increased gravity, weight load and hypodynamics affected the first and last stages in protein catabolism.     

Comparative toxicity of azinphos-methyl to house mice, laboratory mice, deer mice, and gray-tailed voles

A laboratory toxicity study on house mice and laboratory mice (Mus musculus), gray-tailed voles (Microtus canicaudus), and deer mice (Peromyscus maniculatus) was conducted as part of a comprehensive laboratory and field study to field validate laboratory-based risk assessment of pesticides. The single dose oral LD50 for the organophosphorus insecticide azinphos-methyl (Guthion) was 10, 11, 32, and 48 mg/kg body weight in wild house mice, laboratory mice, gray-tailed voles, and deer mice, respectively. Ten-day dietary LC50s were 277 ppm for laboratory mice, 297 ppm for gray-tailed voles, and 1,180 ppm for deer mice. All treated animals lost more weight, consumed less food, and had depressed brain cholinesterase (ChE) activity compared to controls. Five-day LC50s were significantly higher than 10-day LC50s for laboratory mice and deer mice. For all three species, animals that died during dietary LC50 tests had mean ChE activity of 50-55% while survivors had 56-70% of controls. The conclusions were that: (1) Laboratory mice were not representative of deer mice or gray-tailed voles with respect to sensitivity to azinphos-methyl, but provided a conservative estimate for risk assessment; (2) 10-day dietary LC50 tests indicate substantially greater estimates of toxicity of azinphos-methyl to rodents than do 5-day tests; and (3) brain ChE depression of 45-50% was lethal in these species.     

Effect of betaine on the growth performance of chicks inoculated with mixed cultures of avian Eimeria species and on invasion and development of Eimeria tenella and Eimeria acervulina in vitro and in vivo

At 7 d postinoculation (DPI) with a mixed culture of avian Eimeria species, 21-d-old chicks maintained in batteries and floor pens on a diet containing 0.15% (3 lb/ton) betaine plus 66 ppm (60 g/ton) salinomycin were significantly heavier and had significantly lower feed conversion ratios and mortality than chicks fed diets containing 0.15% betaine or 66 ppm salinomycin alone, or the control diet. At 31 DPI, when the chicks were 45 d old, the differences between the diet groups were not as great as at 7 DPI. In vitro, except at high concentrations, betaine was nontoxic to sporozoites of Eimeria tenella or Eimeria acervulina and had little effect on their invasion and development in cultured cells. In vivo, invasion by E. tenella and E. acervulina sporozoites was significantly reduced in all chicks fed diets containing betaine or salinomycin compared with that in control chicks. There was a significant interaction between betaine and salinomycin that impacted on invasion by both species. Overall development of E. tenella did not appear to be adversely affected by addition of betaine to diets containing salinomycin. Conversely, development of E. acervulina was reduced in chicks fed diets containing 0.075% (1.5 lb/ton) betaine plus 66 ppm salinomycin as compared with that in chicks fed salinomycin alone.     

Effects of amino acid restriction during starter and grower periods on subsequent performance and incidence of leg disorders in two strains of male large white turkeys

Male turkeys of two commercial Large White strains (Nicholas 88, BUT 6) were subjected to growth restriction by means of reducing amino acid (AA) content of diets to a minimum of 75% of NRC (1994) suggested levels. There were three periods when diets containing 75% of NRC recommended AA for that age period were fed ad libitum: 0 to 3 wk, 0 to 6 wk, or 6 to 12 wk. A fourth (control) group was not restricted in AA content at any time. When turkeys were not fed the AA-restricted diets they were fed diets formulated to meet a minimum of 100, 110, or 120% of NRC (1994) AA recommendations, which resulted in a 3 x 4 factorial arrangement of treatments with three AA levels by four restriction times. Four pens of 12 males each were fed each AA by restriction time combination. At 18 wk, all birds were scored individually for leg condition and representative samples of turkeys were processed for parts yield. Birds fed restricted diets from 0 to 6 or 6 to 12 wk had significantly lower BW at 18 wk than control birds. Birds fed the restricted diets from 0 to 3 wk did not differ significantly in 18-wk BW compared to control birds but the magnitude of difference was similar to that observed at the end of the restriction period. Feed utilization was not improved by early AA restriction. Restricting early growth resulted in a significantly higher incidence of birds with no leg disorders and a lower incidence of birds with moderate leg disorders than control birds. Feeding higher AA levels during realimentation resulted in a greater severity of leg disorders. Breast meat yield was depressed significantly as severity of early restriction increased. Increasing dietary AA above NRC (1994) recommended levels generally improved performance during realimentation but was not able to compensate for reduced gains during restriction.     

Effects of dietary taurine on egg weight

Two experiments were conducted to determine whether taurine supplementation to laying hens would influence laying performance. In Experiment 1, a total of 120 White Leghorn hens were fed diets supplemented with 0, 0.25, or 0.5% taurine for 5 wk. Egg weight was reduced significantly by supplementing 0.25 and 0.5% taurine; however, taurine did not affect other laying performance variables. In Experiment 2, a total of 240 White Leghorn hens were fed diets supplemented with 0 or 0.5% taurine and 0 or 0.1% methionine for 7 wk. Egg weight was decreased due to supplementing taurine in the diets; however, dietary methionine did not affect egg weight, and there was no interaction between dietary taurine and methionine. These results suggest that dietary taurine has the potential to decrease egg weight without affecting egg production, feed conversion, or body weight.     

Effects of different cereal grains in diets for laying hens on production parameters and liver fat content

Two experiments were conducted with White Leghorn laying hens to study the effects of different cereal grains on production criteria and liver fat content. The results of Experiment 1, in which pullets 21 weeks of age were used for a period of 22 weeks indicated that Gaines wheat or triticale (Trailblazer) were equal to corn in supporting egg production, egg weight and body weight, with comparable feed consumption. Henry wheat(a hard red winter class) was slightly, yet significantly (P less than 0.05) inferior to corn for the above criteria. No significant differences were observed among four treatments in wet liver weight and liver fat content. Hens fed the corn diet had significantly (P less than 0.05) lower carcass fat followed by the hens fed triticale in comparison with those fed Gaines or Henyry wheat. Mortality was very low and not related to dietary treatments. Neither dietary fat nor energy content was related to fat content of liver and carcass of the hens. Body weight and liver fat content were not closely related to each other. Wet liver weight was the only significantly (P less than 0.05) related factor to liver fat content. In the second experiment, in which hens 33 weeks of age were used for an experimental period of 20 weeks, opaque-2 corn was slightly superior to normal corn and triticale was comparable to normal corn in supporting egg production and egg weight. Supplementation of the diets containing the two corns and triticale with lysine failed to improve egg production and egg weight. Hens fed the diets containing either normal corn or opaque-2 corn as the only grain in the diet had significantly (P less than 0.05) higher liver fat content in comparison with hens fed the diet containing triticale as the only grain. Mortality, however, was much higher among hens fed triticale-containing diets in comparison with groups fed corn-containing diets in spite of the fact that they had significantly lower liver fat content. Regardless of dietary treatments or grains used, the hens that died were diagnosed to have fatty liver hemorrhagic syndrome. Dietary fat content was postively and significantly (P less than 0.05) related to liver fat content. Dietary energy or body weight was not closely related to liver content. Liver fat content and mortality were negatively related to each other. The higher for content did not adversely affect laying performance.     

Fatty liver-hemorrhagic syndrome observed in commercial layers fed diets containing chelated minerals

This study was originally conducted to determine the effect of various chloride levels and consumption of chelated versus non-chelated minerals on egg production and eggshell breaking strength. However, the focus of this report changed after fatty liver-hemorrhagic syndrome (FLHS) was observed in hens that consumed diets containing chelated minerals. No FLHS was observed in hens that consumed a diet that contained non-chelated minerals. Four hundred thirty-two 35-week-old commercial laying hens were housed in individual cages in groups of nine hens each. The treatments were factorially arranged (3 x 2) such that six experimental diets differing in chloride levels and in source of minerals were fed for six 28-day laying periods. A significantly higher mortality attributed to FLHS was observed in hens that consumed the diets having chelated minerals as compared with hens that consumed the diets with non-chelated minerals. No difference in mortality was observed among the hens fed the various chloride diets.     

Interferon treatment of hepatitis C: is it virological cure?

Weanling male CD-1 mice were fed low iron (7 ppm), control (120 ppm) and iron loaded diets (3000 or 5000 ppm) for 19 weeks. After seven weeks, the mice received 1.5 mg urethan/g ip, and tumor development was evaluated 12 weeks later. The low iron diet increased the incidence of lung adenomas by 86%. The iron loaded diets did not influence adenoma development. Tumor size was unaffected by iron status (p = 0.297). These results indicate that low iron body status promotes tumor development and are inconsistent with the hypothesis that excess iron promotes cancer growth and that low iron protects against tumor growth.     

Subchronic toxicity of a medium-chain chlorinated paraffin in the rat

Groups of ten male and female weanling Sprague-Dawley rats were fed diet containing 0, 5, 50, 500 or 5000 ppm of a medium-chain chlorinated paraffin (C14-17, 52% chlorination) for a period of 13 weeks. Increased relative liver weight was observed at 500 and 5000 ppm in females and at 5000 ppm in males. Relative kidney weight was increased at 5000 ppm in both sexes. Serum cholesterol was increased in the females in a dose-related manner starting at 50 ppm. At 5000 ppm, animals of both sexes had elevated hepatic UDP-glucuronosyltransferase activity while only females showed increased aminopyrine N-demethylase activity. Increased urinary N-acetylglucosaminidase activity occurred at 5000 ppm in females. Increased urinary ascorbic acid excretion monitored at week 12 and a decreased hepatic vitamin A level were detected in females receiving the 500 ppm diet and male and female rats at 5000 ppm. Mild, adaptive histopathological changes were detected in the liver of rats of both sexes at 500 and 5000 ppm, and in the thyroid of males and females starting at 500 and 50 ppm respectively. Minimal changes were observed in the kidney proximal tubules of male rats fed the 5000 ppm diet and in the inner medulla tubules of female rats fed the 500 and 5000 ppm diets. These data indicate that the medium-chain chlorinated paraffin produces biochemical and histological changes at dietary levels of greater than or = 50 ppm in females and greater than or = 500 ppm in males.     

90-day feeding and one-generation reproduction study in Crl:CD BR rats with 17 beta-estradiol

Over the past several years, there has been increasing concern that chemicals and pesticides found in the environment may mimic endogenous estrogens, potentially producing adverse effects in wildlife and human populations. Because estrogenicity is one of the primary concerns, a 90-day/one-generation reproduction study with 17 beta-estradiol was designed to set dose levels for future multigenerational reproduction and combined chronic toxicity/oncogenicity studies. The purpose of these studies is to evaluate the significance of a range of responses as well as to provide benchmark data for a risk assessment for chemicals with estrogen-like activities. This 90-day/one-generation reproduction study was conducted in male and female Crl:CD BR rats using dietary concentrations of 0, 0.05, 2.5, 10, and 50 ppm 17 beta-estradiol. Endpoints were chosen in order to evaluate both subchronic and reproductive toxicity. In addition, several mechanistic/biochemical endpoints were evaluated for their usefulness in follow-up studies. In the P1 generation, dietary administration of 2.5, 10, and 50 ppm 17 beta-estradiol produced dose-dependent decreases in body weight, body weight gain, food consumption, and food efficiency. At 10 and 50 ppm 17 beta-estradiol, minimal to mild nonregenerative anemia, lymphopenia, decreased serum cholesterol (50 ppm only), and altered splenic lymphocyte subtypes were also observed in the P1 generation. Additionally, at these concentrations, there were changes in the weights of several organs. Evidence of ovarian malfunction, characterized by reduced numbers of corpora lutea and large antral follicles, was observed at 2.5 ppm 17 beta-estradiol and above. Other pathologic changes in males and females fed 10 and 50 ppm 17 beta-estradiol included centrilobular hepatocellular hypertrophy; diffuse hyperplasia of the pituitary gland; feminization of the male mammary glands; mammary gland hyperplasia in females; increased number of cystic follicles in the ovary; hypertrophy of the endometrium and endometrial glands in the uterus; degeneration of seminiferous epithelium; and atrophy of the testes and the accessory sex glands. In the reproduction portion of this study, rats fed 10 or 50 ppm 17 beta-estradiol did not produce litters. While there was no evidence that the 50 ppm treated rats mated, 33.3% of the rats fed 10 ppm mated but did not produce litters. No effects on mating and fertility indices were observed in rats fed 0.05 and 2.5 ppm 17 beta-estradiol. Pup weights at birth were statistically decreased relative to control in the groups fed 0.05 and 2.5 ppm 17 beta-estradiol. Weights of the rats in the 0.05 ppm group recovered by postnatal day 4 and remained similar to control throughout the remainder of the study. The mean gestation length of the 0.05 ppm group was slightly, albeit not statistically significantly, shorter (0.5 days) than that of the control group, which may have contributed to the decrease in birth weight of the 0.05 ppm group. In contrast, the weights of the F1 generation rats fed 2.5 ppm 17 beta-estradiol remained decreased relative to the control group throughout the study. Parental administration of 17 beta-estradiol did not alter anogenital distance in male or female pups. The onset of sexual maturation, as measured by day of preputial separation in males and day of vaginal opening in females, was delayed in male rats fed 2.5 ppm (by 8.2 days) and was hastened in female rats fed 0.05 and 2.5 ppm (by 1.6 and 8.8 days, respectively). The age at vaginal opening ranged from 26 to 37, 26 to 35, and 21 to 25 days for rats fed 0, 0.05, and 2.5 ppm 17 beta-estradiol, respectively. Hence, the range of age at vaginal opening was similar between the control and 0.05 ppm group. The organ weight and pathologic alterations observed in the adult F1 generation rats were similar to those observed in the P1 generation rats. (ABSTRACT TRUNCATED)     

An introduction to sleep disorders--their concept and diagnostic classification

Adult female mink were fed diets supplemented with 0, 0.001, 0.01, 0.1, 1, 10, or 100 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for up to 125 days. There was a dose-dependent decrease in feed consumption and body weights indicative of the "wasting syndrome" previously reported for mink and other species exposed to chlorinated hydrocarbon compounds. Mortality reached 12.5, 62.5, and 100% by day 28 in the 1-, 10-, and 100-ppb groups, respectively, and by day 125, mortality increased to 62.5 and 100% in the 1- and 10-ppb groups, respectively. Adrenal gland weights were significantly greater in the three highest dose groups compared to the control group. The percentage of band neutrophils was also significantly greater in the TCDD-treated groups compared to the control. LC50 (+/- SE) values for 28 and 125 days of dietary exposure to TCDD were calculated to be 4.8 +/- 4.99 ppb and 0.85 +/- 0.64 ppb, respectively. Based on feed consumption of control mink, these LC50 concentrations approximate 0.264 and 0.047 microgram TCDD/kg body weight/day for the 28- and 125-day exposure periods, respectively. These results confirm the sensitivity of mink to TCDD.     

Food for inefficient thought

Sixty Sprague-Dawley rats were fed diets containing 0, 10, 100, 1,000, and 10,000 ppm of methoxychlor for 16 weeks under ad libitum- and restricted-feeding regimens. Methoxychlor at 10,000 ppm was lethal to some rats, reduced food consumption and growth, and increased liver weight relative to body weight. Methoxychlor at 1,000 ppm reduced food consumption and growth of rats fed ad libitum but did not reduce growth of restricted-fed rats. Reduced hepatic storage of vitamin A was detectable when methoxychlor was fed at levels of 100 ppm or higher.     

The effect of feeding various levels of dietary glycine in a pre-experimental diet to one-day old chicks on their subsequent glycine plus serine requirement

Two experiments were conducted to determine the effect of feeding chicks 1=9 days of age various levels of clycine in corn-casein and corn-soybean-corn gluten meal diets upon the subsequent glycine plus serine requirement of chicks during the remaining 10-21 day feeding period. Chicks in Experiment 1 fed corn-casein basal diets with 1.3% additional dietary glycine (2.15% total glycine plus serine) gained significantly (P less than or equal to 0.01) more weight during an initial 9-day feeding period than chicks fed basal diets with 0.3% and 0.9% supplemental glycine. Chicks fed the 2.15% glycine plus serine diets during the first 9 days posthatching and then fed basal diets containing 0.3% supplemental glycine (1.15% total glycine plus serine) for a 10-21 day feeding period gained weight equivalent to chicks fed 2.15% glycine plus serine diets for the entire 21-day period. The corn-casein basal diet contained 21.0% protein and 0.85% glycine plus serine. Chicks in Experiment 2 fed corn-soybean-corn gluten meal diets containing 1.8% glycine plus serine did not respond to glycine supplementation druing the initial 9-day feeding period or the 10-23 day feeding period. The results suggest feeding optimum levels of glycine to chicks during the first nine days after hatching decreases the requirement of glycine and serine during subsequent feeding periods.     

Mortality and production characteristics of laying chickens fed high- and low-erucic acid rapeseed oils

Laying pullets were fed a diet supplemented with three percent of either high-erucic acid rapeseed (HEAR) oil or low-erucic acid rapeseed (LEAR) oil for 39 weeks. Egg production for the period was 78.8 and 80.1% by the birds fed the respective oils. Average egg weights were 56.8 and 58.7 g. respectively. Gains in body weight, liver weight and adrenal gland weight were similar with the two types of oil fed. Feed consumption was similar for the two groups of birds. The efficiency of utilization of the diet containing HEAR oil was accordingly lower than that of the diet containing LEAR oil. In the birds fed HEAR and LEAR oil respectively mortality attributed to metabolic disorders of the reproductive system, liver, and kidney was 3.3% and 1.2%. Mortality from other causes in the birds fed the two oils was 3.2 and 3.8% of the original populations.     

Effect of protein-induced calciuria on calcium metabolism and bone status in adult rats

45Ca-labeled adult male rats were fed diets high in protein to determine long-term effects on calcium metabolism and bone status. Factors influencing renal excretion of calcium were examined for their involvement in protein-induced hypercalciuria. Control rats were fed a 6% casein diet. Test diets contained 6% casein plus 24% protein as lactalbumin, beef, casein, soy, egg white or gelatin. All diets were equal in Mg, P, and Ca. Collections made during the 20-week feeding regimen indicated a transient but marked calciuria (greater than or equal to 200% of control) occurring at or prior to days 56-59 by rats fed the lactalbumin, egg white, gelatin (P less than or equal to 0.001) and 30% casein (P less than or equal 0.01) diets. Soy and beef diets were not calciuric. At days 56-59, rats fed lactalbumin, 30% casein, soy and egg white exhibited significantly depressed urinary specific activity of calcium (P less than or equal to 0.001), and all rats fed test diets produced higher fecal endogenous calcium, suggesting an increased absorption. No compositional differences indicative of bone resorption were present in the femur or mandibles of any rat fed test protein, dismissing bone as the source of calciuria. End-products of protein metabolism known to chelate calcium or compete with its renal reabsorption were significantly correlated with urinary calcium; these included sulfate, oxalate and sodium.