Lower Final Body Weight Research Articles

Dietary protein level and natural food management in the culture of blue (Litopenaeus stylirostris ) and white shrimp (Litopenaeus vannamei ) in microcosms

The effect of dietary protein level and natural food management on the production parameters of blue and white shrimp, as well as on water quality, was evaluated in a microcosms system (plastic pools simulating aquaculture ponds). Two experimental trials were carried out in the facilities of DICTUS, University of Sonora, Northwest México. Treatment with low protein diet (LP) consisted of a low protein input (diet with 250 g kg−1 crude protein) through the culture period; treatment with high protein diet (HP) consisted of a high protein input (diet with 400 g kg−1 crude protein) through the trial, and finally treatment VP consisted of an adjustment of protein input (diets with 250, 350 or 400 g kg−1 crude protein), depending on the abundance of biota (zooplankton and benthos) in the system. Each species responded differently to the treatments. For blue shrimp, low protein input resulted in the lowest final body weight (12.9 ± 0.6 g) and biomass (696.0 g pool−1). Survival and feed conversion ratio were similar in the three treatments. For white shrimp, the best growth, biomass and food conversion ratio were obtained in the low protein input treatment. Water quality parameters such as nitrate, ammonia and organic matter during the two trials, were better for LP and VP treatments. White shrimp seems to have lower protein requirements than blue shrimp. For the blue shrimp culture, adjusting protein input according to natural food abundance (zooplankton and benthos) in the system, seems to be advantageous because of the possibility of getting a production similar to that obtained with a high protein input through the farming period, but at lower feed cost, and with a lower environmental impact. It is concluded that a high protein input through the whole farming period is not the best feeding strategy for any of the two species.

Desempenho de bezerros da raça holandesa com desaleitamento aos 28 ou 56 dias de idade, com ou sem aditivo à base de oligossacarídeo de manana

Vinte e quatro bezerros da raça Holandesa foram utilizados num experimento com delineamento completamente casualizado, em arranjo fatorial 2x2 (desaleitamento aos 28 ou 56 dias, com ou sem a adição de oligossacarídio de manana à dieta), e seis repetições por tratamento. Não houve interação entre os fatores período de aleitamento e uso ou não de aditivo. O desaleitamento aos 28 dias, em comparação com 56 dias, resultou, aos 56 dias de idade, em menor peso final, menor ganho médio diário de peso, maior consumo de concentrado, menor consumo total de matéria seca e pior conversão alimentar. Não houve diferenças em relação às medidas corporais iniciais e finais de altura de cernelha, perímetro torácico e abdominal, embora o desaleitamento aos 28 dias tenha diminuído o ganho médio diário de perímetro torácico. Em um levantamento dos custos de alimentação, medicamentos e mão-de-obra veterinária, os animais desaleitados aos 28 dias apresentaram menor custo total individual e menor custo por kg de ganho de peso. O emprego do aditivo não afetou as dimensões corporais, porém resultou em maior ganho de peso, final e diário, e melhor conversão alimentar, reduzindo o custo médio por kg de ganho de peso.

Effect of low fat diet on lipid absorption and fatty-acid transport following bowel resection.

Low-fat diets (LFD) are used extensively in many different clinical conditions. However, the effect of this diet on lipid absorption and cellular long-chain fatty-acid (LCFA) transport is unknown. Fatty-acid translocase (FAT), the rat homologue of human CD36, is one of several LCFA plasma-membrane transport proteins that may play an important role in intestinal lipid uptake. The purpose of this study was to investigate the effects of a LFD on intestinal expression of FAT/CD36, enterocyte fatty-acid transport, and in-vivo lipid absorption in rats following bowel resection. Adult male Sprague-Dawley rats were divided into five experimental groups: normal rats fed normal chow(NR-NC) (10 kcal% fat), normal rats fed a LFD (NR-LFD) (3 kcal% fat), sham rats fed normal chow (Sham-NC), short-bowel syndrome rats fed normal chow (SBS-NC), and SBS rats fed a LFD (SBS-LFD). SBS rats underwent 75% small-bowel resection, while sham animals underwent bowel transection and reanastomosis. Food intake, fecal mass, and fecal fat were measured over the last 3 days before death on day 14. Final body weight, plasma lipids and protein, and tissue total lipids in liver, adipose tissue, and intestine were determined at death. Total RNA from the mucosa of the duodenum, jejunum, and ileum was extracted for Northern blot analysis to determine fatty-acid translocase (FAT)/CD36 mRNA levels. An established cellular LCFA transport assay was used to determine isolated enterocyte [3H]-oleate uptake. Students t-test was used to determine statistical significance (P < 0.05). NR-LFD rats demonstrated a small increase in overall food absorption and no change in fat absorption compared to NR-NC animals. A significant decrease in FAT/CD36 mRNA levels was seen in the duodenum and jejunum in NF-LFD rats (vs NR-NC) and was accompanied by reduced LCFA transport by isolated enterocytes from the jejunum and ileum. SBS-LFD rats demonstrated decreased FAT/CD36 mRNA levels in all three segments and a concomitant decrease in LCFA uptake enterocytes compared to the SBS-NC group. In addition, SBS-LFD rats showed significantly lower final body weight and plasma lipids compared to SBS-NC animals.

Effect of Different Dietary Energy Levels in Early and Middle Fattening Periods on Fattening Performance of Holstein Steers

Thirty-six Holstein steers (8 months of age) were allocated to three different dietary programs with low, medium, and high energy levels (LE, ME, and HE, respectively) in early (18 weeks) and middle (16 weeks) fattening periods. The TDN (% of DM) of LE, ME, and HE were 73, 75, and 77 in the early period, and 79, 81, and 84 in the middle period, respectively. All the steers were fed the same finishing diet with 85% TDN for 16 weeks. Lower DM intake and lower weight gain were observed in the HE in early period as compared with the LE. Although TDN intake was not different among the diets, the HE showed lower TDN efficiency than the LE in the early period, presumably caused by a restriction of metabolizable protein. There were tendencies towards lower final body weight in the HE and larger reduction in DM intake in the LE in the finishing period, whereas no statistical difference in carcass traits was seen among the diets except for the occurrence of high contents of C 16: 1, C 18: 2, and/or C 18: 3 in the HE. These results suggest that dietary TDN level of 75% or slightly less for the early period and a gradual change in dietary energy level would be commendable for successfully fattening Holstein steers.

Effects of chronic exposure to γ-HCH (Lindane) on brain serotonergic and gabaergic systems, and serum cortisol and thyroxine levels of rainbow trout, Oncorhynchus mykiss

Rainbow trout (Oncorhynchus mykiss) were implanted intraperitoneally with 0.5 ml.100 g−1 body weight of coconut oil alone (controls) or coconut oil contaning 0.05 mg of γ-HCH (Lindane). After 18 days, changes in brain serotonin and GABA metabolism, as well as in serum cortisol and thyroxine levels, were measured. A lower final body weight was observed in γ-HCH treated fish when compared with control fish. No significant differences were found for serum thyroxine levels between control and treated fish, but a significantly higher cortisol level was found in the γ-HCH-implanted trout. Although GABA levels did not differ significantly in any brain region in the two treatment groups, the activity of the serotonergic system was significantly altered by the pesticide in both the hypothalamus and the telencephalon.

Effect of metabolic acidosis on renal tubular sodium handling in rats as determined by lithium clearance.

Systemic metabolic acidosis is known to cause a decrease in salt and water reabsorption by the kidney. We have used renal lithium clearance to investigate the effect of chronic, NH4Cl-induced metabolic acidosis on the renal handling of Na+ in male Wistar-Hannover rats (200-250 g). Chronic acidosis (pH 7.16 +/- 0.13) caused a sustained increase in renal fractional Na+ excretion (267.9 +/- 36.4%), accompanied by an increase in fractional proximal (113.3 +/- 3.6%) and post-proximal (179.7 +/- 20.2%) Na+ and urinary K+ (163.4 +/- 5.6%) excretion when compared to control and pair-fed rats. These differences occurred in spite of an unchanged creatinine clearance and Na+ filtered load. A lower final body weight was observed in the acidotic (232 +/- 4.6 g) and pair-fed (225 +/- 3.6 g) rats compared to the controls (258 +/- 3.7 g). In contrast, there was a significant increase in the kidney weights of acidotic rats (1.73 +/- 0.05 g) compared to the other experimental groups (control, 1.46 +/- 0.05 g; pair-fed, 1.4 +/- 0.05 g). We suggest that altered renal Na+ and K+ handling in acidotic rats may result from a reciprocal relationship between the level of metabolism in renal tubules and ion transport.

Effects of Subchronic Exposure of Monochloramine in Drinking Water on Male Rats

A subchronic rat study with paired-water control was conducted to resolve the question of whether monochloramine at 200 ppm in drinking water can cause reduced body weight gain and other changes observed in earlier investigations. Male Sprague–Dawley rats (93 ± 5 g) were divided into three groups of 10 rats each: the treatment group was fed drinking water containing 200 ppm monochloramine, the control group was fed bicarbonate-buffered waterad libitum,and the paired-water control rats were given a daily volume of bicarbonate-buffered water equal to that consumed by the monochloramine treatment group. Compared to the control group, rats in the treatment group consumed an average of 42% less fluid and 16% less food over the 13-week treatment period and had 15–20% lower final body weight gain. Similar degrees of reduction in food consumption and body weight gain were observed in the paired-water rats. A decreased liver to body weight ratio occurred in the treatment and paired-water groups. Increased inorganic phosphate, albumin, total protein, and urea nitrogen were detected in sera from both the treatment group and the paired-water groups. The paired-water animals had lower levels of white blood cells and lymphocytes, while the paired-water and monochloramine-treated groups had reduced monocyte counts. Except for a slightly increased response to Con A observed in splenic lymphocytes of the monochloramine-treated rats (versus the paired-water), no significant changes were found in mitogen responsiveness to T cell, B cell, and B plus T cell mitogens or in splenic natural killer (NK) cell activities. There were no significant changes in serum levels of IgG, IgA, and IgM. The following biochemical parameters showed no significant variations among the three groups: serum thyroxin, liver phase I (PROD, EROD, and MROD) and phase II (UDPGT and GST) drug-metabolizing enzyme activities; serum and liver thiobarbituric acid-reactive substances (TBARS); bronchoalveolar lavage fluid protein andN-acetylgluosaminidase (NAGA) activity; and urinary ascorbic acid, protein, and NAGA activity. Histopathological examination revealed minimal to mild adaptive changes in the liver of the paired-water and monochloramine-treated rats and in the thyroid of the monochloramine-treated animals. No treatment-related cytological changes were found in red cells and bone marrow. The results indicate that the reduced body weight gain and the minor biochemical, hematological, immunological, and histopathological changes associated with subchronic exposure to 200 ppm monochloramine in drinking water (equivalent to an intake of 21.6 mg/kg/day) were largely related to the reduced water intake and food consumption and not caused by monochloramine.

Salt Tolerance of Nestling Laughing Gulls: An Experimental Field Investigation

-Although Laughing Gulls (Larus atricilla) in southern New Jersey nest in highly productive salt marshes, adults commonly forage at inland sites when they have young in the nest. Foods from these inland sites have much lower levels of salt than typical marine foods available near the breeding colonies. I hypothesized that Laughing Gulls optimize growth and survival of their offspring by selecting nestling diets that minimize the amount of salt intake. I investigated the role of dietary salt intake on growth of young by providing salt supplements to groups of nestlings in 2 experiments conducted in 1993 and 1994. Dietary salt supplements administered in 1993, but not in 1994, slowed nestling growth and resulted in lower final body weights, total head lengths, and exposed culmen lengths. Nestlings receiving lower salt supplements fared better. By feeding their chicks inland foods, adults may minimize osmotic stress for their young and thereby enhance their growth and survival. Received 19 May 1997, accepted 3 August 1997, final version received 27 August 1997.

The effect of substituting Kenyan Serena sorghum for maize in broiler starter diets with different dietary crude protein and methionine levels

Currently there is interest in many parts of Africa in developing crops which can be grown in the semi-arid regions to help alleviate a feed and food shortage. Sorghum is well suited to cultivation in areas that are too dry or too hot for the production of other cereals. Although sorghum is similar in composition to maize, brown sorghum contains the anti-nutritive factor tannin. The possibility of overcoming any detrimental effects of sorghum tannin on the growth rate and feed efficiency of broiler chicks by supplementing the diet with intact crude protein (CP) or D,L-methionine (Met) was studied in two 4-week feeding trials of 280 chicks each. In each trial the effects of feeding maize or brown sorghum were compared under three dietary specifications (control, increased CP, increased Met). In both trials, the tannin content of the control brown sorghum diet was 1.3% catechin equivalents (dry matter basis). A seventh diet, with dietary specifications similar to the control diets, was included in each trial for comparison with the six main diets. In Trial 1 the seventh diet contained a combination of white and brown ( w b ) sorghum ( 50 50 , w w ) as the main energy source while in Trial 2 the main energy source of the seventh diet was white sorghum alone. In both trials there were no significant differences in final body weight among the three control diets (770.2, 759.0, and 753.0 g for the broilers on the maize, brown sorghum, and w b sorghum diets in Trial 1; and 822.7, 764.8, and 827.2 g for the broilers on the maize, brown sorghum, and white sorghum diets in Trial 2). In addition, there were no significant differences in feed conversion ratio (FCR) between the maize and brown sorghum fed broilers (2.01 vs. 2.03 in Trial 1; and 1.82 vs. 1.94 in Trial 2). In Trial 2, however, the FCR for the broilers receiving the white sorghum diet (1.73) was significantly lower than for those receiving the brown sorghum control diet (1.94), but not significantly different from those receiving the maize control diet (1.82). There was no effect of Met supplementation on final body weight or FCR in either trial. In Trial 1, increasing dietary CP content had no effect on final body weight or FCR for both the maize and brown sorghum fed broilers. In Trial 2, however, increasing the dietary CP content resulted in significantly lower final body weights (708.2 vs. 822.7 g) and higher FCR (2.06 vs. 1.82) for the maize fed broilers. The results of this study suggest that high tannin sorghum can be substituted for white maize in broiler starter diets with no significant adverse effects on growth or feed efficiency. The dietary treatments of increased CP or Met levels, which have been reported to be successful at overcoming the detrimental effects of sorghum tannins, were not required. A leg abnormality previously reported by other sorghum researchers was observed in both trials but the incidence and severity were low. Broilers receiving maize based diets with increased Met were most affected suggesting that the abnormality is related to increased Met and not to tannins.

Furosemide Reduces the Incidence of Pulmonary Hypertension Syndrome (Ascites) in Broilers Exposed to Cool Environmental Temperatures

The incidence of pulmonary hypertension syndrome (PHS; ascites) was evaluated in two experiments using broiler breeder male by-product chicks exposed after 3 wk of age to cool environmental temperatures (10 to 15 C). In Experiment 1, 3- to 6-wk-old birds were fed a grower diet to which 0 (Control), .001, .005, .010, or .015% furosemide had been added. All groups in Experiment 1 were fed a finisher ration containing no furosemide during Weeks 7 to 8. In Experiment 2, the Control group received no furosemide, a second group received .015% furosemide during the grower phase only (Weeks 3 to 6), and the third group received .015% furosemide during the grower and finisher phases (Weeks 3 to 8). Cumulative PHS mortality was significantly reduced by furosemide in both experiments. Compared with Controls, birds fed .015% furosemide did not have lower (P = .077) final body weights in Experiment 1 but did have significantly lower final body weights in Experiment 2. Lower levels of furosemide significantly reduced PHS mortality without reducing body weights. Furosemide did not improve feed conversion in either experiment. Neither body weight on Day 1 or 21 nor net Day 1 to 21 weight gain were predictive of susceptibility to PHS during the subsequent grower and finisher intervals in either experiment. On Day 55 of Experiment 2, large healthy birds fed .015% furosemide had significantly lower right:total ventricular weight ratios than control birds, indicating that furosemide reduced right ventricular hypertrophy, presumably by reducing pulmonary arterial pressure.

COMPARISON OF FISH GONADS AND FISH MEAL AS MAJOR COMPONENTS IN THE DIETS OF YOUNG AFRICAN SHARPTOOTH CATFISH,CLARIAS GARIEPINUS(BURCHELL)

Summary The replacement of fish-meal (two sources, arbitrarily designated FMA and FMB), with either freeze dried (GVD) or oven dried (GOD) gonads of Clarias gariepinus in a starter diet for larvae of this species, was tested. No significant difference in larval growth rates was noted between the various protein sources, although fish receiving FMA had a significantly lower final body weight (p ≤ 0.05). Fish which received gonads as a protein source had a significantly higher total body lipid (GOD = 28.47% Dry Mass—DM) than those receiving fish-meal (FMA = 13.97% DM). The whole body fatty acid composition was influenced by that of the fatty acid composition of the protein source. The hepatocytes of the fish receiving the gonads as protein source showed 100% lipid accumulation and degenerative changes, whilst those from fish-meal fed fish showed none.

Effects of repeated cycles of starvation and refeeding on lungs of growing rats.

Adult male rats were subjected to four cycles of mild starvation (2 wk) and refeeding (1 wk) and were compared with a fed group. Starvation was induced by giving rats one-third of their measured daily food consumption. During each starvation cycle, rats lost approximately 20% of their body weight. Despite catch-up growth and overall weight gain, starved rats had lower final body weight than fed rats. Lung dry weight and lung volumes were also reduced in the starved group. The mechanical properties of air- and saline-filled lungs did not change significantly with repeated cycles of starvation. Mean linear intercept was similar in the two groups, but alveolar surface area was reduced in the starved rats. Total content of crude connective tissue and concentration per lung dry weight of hydroxyproline and crude connective tissue were reduced in starved rats. We conclude that lung growth is retarded in growing rats subjected to repeated cycles of mild starvation and refeeding, as manifested by smaller lung volume and reduced alveolar surface area. Because alveolar size is unchanged, a reduced number of alveoli is most likely responsible for decreased lung volumes.

Toxicity of T-2 toxin and its interaction with deoxynivalenol when fed to young pigs

Sixty 12-wk-old pigs were fed a corn–barley–soybean type diet in a 2 × 5 factorial experiment. Two mycotoxin, corn-based premixes were added: one with and without deoxynivalenol (DON) supplement (2.5 mg kg−1 feed) and the other with T-2 toxin at levels of 0.0, 0.4, 0.8, 1.6 and 3.2 mg kg−1 feed. After a 5-wk feeding period the pigs were killed; major organs were examined grossly and microscopically, and blood and tissue samples were taken for biochemical and hematological analyses. Lower final body weight and daily gain appeared (P &gt; 0.05) to be associated with increasing dietary T-2 toxin content. Feed intake followed a similar trend. The performance of pigs fed the DON-supplemented diets was significantly less than for diets without the DON. There was an interaction between DON and T-2 toxin, with differences in weight gain and feed intake, at the two levels of DON, being smaller at the intermediate levels of T-2 toxin. The incidence of lesions on the mucosa of the pars esophageal region increased with increasing levels of T-2. Otherwise, there was little evidence that T-2 affected any of the major organs examined at necropsy or the biochemical and hematological criteria. It seemed that any effects detected were attributable more to DON and its interaction with T-2 than to the presence of T-2 toxin alone. Key words: Pigs, T-2 toxin, DON, toxin interaction

High stocking density alters the energy metabolism of brook charr, Salvelinus fontinalis

Brook charr reared for 30 days at a high stocking density (120 kg/m 3) had significantly lower final body weight and reduced food consumption when compared to fish reared at a lower stocking density (30 kg/m 3). There was no effect of stocking density on plasma cortisol and T3 concentrations, while plasma T4 concentration was lowered in fish held at high stocking density. Plasma glucose levels, liver glycogen content and hepatosomatic index were significantly lower in fish reared at high stocking density, while plasma protein and free fatty acid (FFA) levels were not significantly different between groups. There were significantly higher activities of hepatic phosphofructokinase, fructose biphosphatase, 3-hydroxyacyl CoA dehydrogenase, glycerol kinase and glycerol-3-phosphate dehydrogenase in fish held at high stocking density compared with those at low stocking density. Hepatic hexokinase and glucose-6-phosphate dehydrogenase activities were significantly lower in fish at high stocking density compared with those at low stocking density, while there were no differences in pyruvate kinase, glucose-6-phosphatase, phosphoenolpyruvate carboxykinase, glutamate dehydrogenase, glutamate pyruvate transaminase and glutamate oxaloacetate transaminase between the groups. These results suggest that high stocking density has the effect of mobilizing triglyceride sources, promoting gluconeogenesis from glycerol, but has little effect on protein metabolism.

Effects of sympathectomy on heart size and function in aortic-constricted rats.

Effects of chemical sympathectomy with 6-hydroxydopamine on left ventricular mass, norepinephrine content, and performance in aortic-constricted and sham-constricted rats were examined. Sympathectomy did not affect mean arterial pressure but it led to lower final body weights in aortic-constricted rats. Of the hypertensive aortic-constricted rats, those that had also been sympathectomized showed greater increases in left ventricular weight-to-body weight, right ventricular weight-to-body weight, and lung weight-to-body weight ratios. Left ventricular norepinephrine content was depressed by either sympathectomy or aortic constriction and was severely depleted by their combination. Sympathectomy had no effect on maximal cardiac output or left ventricular stroke work during rapid saline infusion. In aortic-constricted rats, however, it lowered heart rate during the infusion and increased left ventricular end-diastolic pressure at peak stroke work. This evidence suggests that elimination of the adrenergic nervous system's chronotropic influence promotes greater left ventricular filling, and the resultant increase in preload may importantly contribute to the stimulation of cardiac hypertrophy.

Growth and physiological condition of black ducks reared on acidified wetlands

Acid deposition has been identified as one of several possible factors contributing to the decline of some waterfowl populations in North America. In an effort to examine the effects of acidification on black duck (Anas rubripes) recruitment, growth and physiological condition were monitored in ducklings foraging for a 10–day trial (days 10–20 of life) on acidified (pH 5.0) and circumneutral (pH 6.8) fish-free emergent wetlands. Acidification of these wetlands suppressed phytoplankton and algal growth, and reduced invertebrate biomass. Ducklings maintained on acidified wetlands grew poorly compared with ducklings reared on circumneutral wetlands, as evidenced by lower final body weight and culmen and tarsus length. Plasma growth hormone concentration was elevated and triiodothyronine levels were lower in stunted ducklings, in part substantiating impairment of growth-regulating processes. Ducklings exhibiting poor growth tended to have lower hematocrit, lower plasma protein, glucose, and cholesterol concentrations, and higher uric acid levels, presumably reflecting alterations in metabolism and development due to inanition. These findings suggest that acid deposition may lower food production in wetlands and ultimately impair duckling growth, condition, and survival.

Dietary carbohydrate and growth, body composition and heat increment in rainbow trout (Salmo gairdneri)

A study was conducted to determine growth, body composition and heat increment (HI) of rainbow trout reared on isonitrogenous high digestible carbohydrate (HC) and high fat (HL) diets at 15°C. Trout reared on the HC diet had a significantly lower final body weight and carcass lipid content and a significantly higher feed:gain ratio and carcass protein content than trout reared on the HL diet after 12 weeks on the test diets. The lower carcass lipid composition indicates that trout do not readily convert dietary carbohydrates into fat. HI of trout reared on the HC diet was significantly higher than that of fish reared on the HL diet. Considering the poor utilization of dietary carbohydrates as an energy source and the apparently low conversion of dietary glucose into fat, the cause of the higher HI associated with the HC diet is not completely understood. However, it is possible the elimination of excess dietary glucose is an energy dependent process resulting in an increased heat production which would partly account for the increased HI. Furthermore, if the HC diet is a low net energy diet, then the metabolism and utilization of dietary and tissue proteins (amino acids) for energy by the trout may also be partly responsible for the increased HI of the trout reared on the HC diet.

Effect of ascorbic acid on dietary copper toxicity in rainbow trout ( Salmo gairdneri Richardson)

Triplicate groups of juvenile rainbow trout ( Salmo gairdneri) were reared for 16 weeks on practical trout diets containing graded levels of ascorbic acid (0, 100, 1000 or 10 000 mg/kg) with or without a copper supplement of 800 mg/kg. At the end of 16 weeks, trout reared on copper-supplemented diets had significantly lower final body weights than trout reared on diets without supplemental copper. Supplementation with ascorbic acid up to and including 10 000 mg/kg diet did not appear to affect markedly either the absorption or metabolism of copper. However, ascorbic acid supplementation at a level of 10 000 mg/kg did result in a small but statistically significant increase in final body weight of trout reared on 800 mg Cu/kg diet when compared with trout reared on the three lower levels of ascorbic acid. Ascorbic acid concentrations in the head kidney and liver increased with dietary ascorbic acid supplementation, but were not affected by dietary copper supplementation. Copper levels in the kidney, liver and whole body increased with dietary copper supplementation but were not affected by dietary ascorbic acid level. Zinc levels in the liver and whole body increased with dietary copper supplementation while zinc levels of the kidney were not affected. Ascorbic acid supplementation had no effect on the zinc content of the kidney or liver. Iron levels in the kidney were variable, but showed no relation to dietary treatment; however, iron levels in the liver were affected and indicate some interaction in the metabolism of copper and iron in the trout. It was concluded that dietary ascorbic acid supplementation up to 10 000 mg/kg does not significantly alleviate dietary copper toxicosis in juvenile rainbow trout.

The effects of exercise and a moderate hypercholesterolemic diet on plasma and hepatic lipoproteins in the rat

Exercise generally has been found to produce beneficial effects on plasma lipid and lipoprotein profiles, but the mechanisms involved and possible dietary interactions have not been well defined. Weanling male Fischer 344 rats were assigned to three groups: normocholesterolemic diet sedentary (NS), hypercholesterolemic diet sedentary (HS), and hypercholesterolemic diet exercised (HE). Exercise consisted of treadmill running at 1.2 to 1.4 km/h at a 9% grade, six days weekly, for a 10-week experimental period. Lipoproteins from plasma and from a recirculating in situ liver perfusion system were then isolated and analyzed. The values of several parameters for HE tended to fall intermediate between HS and NS. Final total plasma cholesterol and liver cholesterol concentrations were significantly different among all three groups (HS > HE > NS). Plasma HDL-cholesterol and phospholipids and perfusate HDL-cholesterol production rate per gram liver were all significantly lower in HS v NS, with HE lying in between. Plasma HDL protein was lower in HS than in both other groups. Plasma total triglyceride levels were significantly lowered by exercise, but neither plasma nor perfusate VLDL triglyceride levels differed significantly among the three groups. Food intakes of HE and HS rats were similar, but HE rats had significantly lower final body weights. The results suggest that (1) exercise may ameliorate many of the changes in lipoprotein and cholesterol metabolism induced by a diet containing lard and cholesterol, and (2) some of these changes may be mediated by changes in hepatic lipoprotein production.

HATCHABILITY OF EGGS AND PERFORMANCE OF SCWL AND BROILER BREEDER HENS FED SOYBEAN MEAL AND FABABEAN MEAL DIETS

Two experiments were conducted to determine the effects of feeding fababean meal diets to laying hens. Body weight, feed consumption, egg production, egg weight, eggshell strength, and hatchability of eggs were the parameters recorded. In exp. 1, where two types of hens (Single Comb White Leghorn (SCWL) and broiler breeders) were maintained in floor pens, hens fed a diet containing fababean meal had lower final body weights, lower average egg weight, and lower percentage hatchability of eggs than those fed soybean meal. Feed utilization, egg production, and eggshell strength were not significantly affected by diets. In exp. 2, in which SCWL were maintained in cages, hens fed diets containing 29.75% fababean meal required more feed per dozen eggs, had lower egg weights and had lower percentage hatchability than hens fed diets containing 7.20% soybean meal. Body weights, feed per bird per day, egg production, and eggshell strength were not significantly affected by diets. Supplemental dietary lysine improved feed conversion and percent hatchability of eggs for hens fed the fababean diets. The combined number of early dead chicks and infertile eggs was higher for eggs from the hens fed fababean meal diets than those fed soybean meal diets.