Depressed Growth Rate Research Articles

INFLUENCE OF LEVEL OF COPPER SUPPLEMENT AND REMOVAL OF SUPPLEMENTAL COPPER FROM THE DIET ON THE PERFORMANCE OF GROWING-FINISHING PIGS AND ACCUMULATION OF COPPER IN THE LIVER

One hundred crossbred pigs were employed in two trials to study the effects of various periods of copper supplementation of the diet at several levels to a maximum of 250 ppm on the performance of growing-finishing pigs, and the accumulation of copper in the liver. The presence of supplemental copper in the diet for any period or at any level did not significantly improve the growth rate of pigs. When included in the diet up to 23, 46, or 69 kg liveweight there was a trend to improved growth rate; however, when included in the diet until 92 kg, growth was depressed. This depression was significant (P < 0.05) only for the 250-ppm level in experiment 2. Removal of supplemental copper from the diet at 23, 46, or 69 kg liveweight depressed growth rate to 92 kg. The presence of supplemental copper in the diet at all levels studied significantly (P < 0.01) increased liver-copper concentration. Removal of copper from the diet at 23 or 46 kg liveweight reduced liver-copper concentration measured at 92 kg liveweight to control levels; removal from the diet at 69 kg liveweight reduced liver-copper concentration at 92 kg by 50%.

Sterol and fatty acid synthesis in developing brains of three myelin-deficient mouse mutants

1. 1. The rate of sterol synthesis and the level of hydroxymethylglutaryl-CoA (HMG-CoA) reductase were previously shown to be subnormal in the myelin-deficient brains of jimpy ( jp/Y) mutants. To determine whether these changes were specific for the jimpy mutation, rates of sterol synthesis and other aspects of lipid synthesis in jimpy brains were compared with those in the brains of two other mutants with defective myelination of the central nervous system, quaking ( qk/qk) and myelin synthesis deficiency ( msd/Y). 2. 2. The rate of sterol synthesis from [1- 14C]acetate or from [2- 14C]mevalonic acid and the level of HMG-CoA reductase were depressed in all three mutations at the earliest age at which clinical symptoms of the disorders were apparent. Ratios of cholesterol to desmosterol in developing brains of the three mutations were normal. 3. 3. The heat stability and the K m (HMG-CoA) of brain HMG-CoA reductase were not affected by the three mutations. 4. 4. The rate of fatty acid synthesis from [1- 14C]acetate was depressed in qk/qk brains but not in jp/Y or msd/Y brains. 5. 5. Rates of sterol, fatty acid, and CO 2 production in brain were not reduced in two neuromuscular mutants (reeler ( rl/rl) and oscillator ot/ot) with depressed growth rates but without known myelin deficiencies or in normal immature mice deprived of food, indicating that inadequate nutrition was not a cause for the observed deficiencies in lipid synthesis rates.

The Live-Weight Gain of Growing Pigs Experimentally Infected with Massive Doses of Hyostrongylus Rubidus (Nematoda) Larvae

SUMMARY Clinical symptoms of mild fever, listlessness, inappetite, diarrhoea, and reduced weight gains are described for the first time following pure infections of H. rubidus in minimal disease (M.D.) growing pigs. Clinical symptoms are most marked 3–5 days and 20–28 days after infections with 200,000 or 500,000 infective larvae. Lower infestation rates have caused no debility to growing animals. The depressed growth rate is most marked 3–4 weeks after infection.

The influence of Myrmica queen head extracts on larval growth

The heads of fertile Myrmica rubra queens have been extracted for lipids, fractionated into sterols, hydrocarbons, sterol esters, triglycerides, diglycerides, monoglycerides, and free fatty acids. All but the sterols (mainly cholesterol) were tested for effects on larval growth and it was found that the free fatty acids depressed growth rate and reduced survival. No other fractions were effective. In this respect the extracts only simulated one of the several known queens' actions. A direct action of the extract through the larval skin was proved. The free fatty acids were analysed and their mean relative compositions listed. The saturated/unsaturated ratio is 0·45 and C18 compounds together comprise about 72 per cent of the total. Oleic acid represents about 50 per cent of the total free fatty acids. Both 9-oxodec-2-enoic acid and 9 hydroxy-dec-2-enoic acid, important in the honey-bee, are absent from Myrmica queens.

The Influence of Several Histomoniastats on Performance of Large White Turkeys

HISTOMONIASIS (blackhead disease or infectious enterohepatitis) continues to be one of the major disease problems in turkey production. The prevention and treatment of blackhead disease is obviously of great economic importance to the turkey industry and various drugs have been developed for this purpose. It is desirable that these compounds themselves do not impair performance, especially when administered continuously at prophylactic levels.DeVolt and Holst (1948, 1949) studied the effect of chlorohydroxyquinoline and iodochloroxyquinoline of histomoniasis in turkeys. While these drugs prevented the occurrence of the disease, they depressed growth rate because of decreased food intake. Several reports have indicated that 2-amino-5-nitrothiazole (Enheptin-T) would prevent the occurrence of histomoniasis when fed at 0.05% of the diet, but feed consumption and growth rate were decreased (Jungherr and Winn, 1950; Seeger et al., 1950; McGregor, 1951 a, b; DeVolt et al, 1954; Grumbles et al, 1952 a, b).McGuire and Morehouse (1952)…

Nutritive Value of Glycols for Poultry Feed

As the first trial to get energy sources for poultry feed which are supplied without cultivating the land or fishing in the sea, nutritive value of glycols, one of petrochemicals, was studied with growing chicks by bioassay technique.In the preliminary trial 40 7-day-old male White Leghorn chicks were fed diets containing either 0 or 5% of 1, 2-propanediol (propylene glycol, PG) for 9 days and thereafter dietary level of PG were steped up to 10 and 20% at every 9 days. Growth rate of the chicks fed diet with 5% of PG throughout 27 days of the experimental period was slightly better than and feed efficiency, appearance and health of the chicks and droppings were similar to those of chicks on the control diet without PG. On the other hand, the performance of chicks fed the diets with 10% PG after feeding the diets with either 0 or 5% PG for 9 days and that of chicks fed the diets with 20% PG after feeding the diets containing 0, 5 or 10% PG for another 9 days were inferior to those of the chicks on the diets of either 0 or 5% PG throughout the experimental period. Especially, droppings of the chicks on high PG level was loose with peculiarly bad smell. Apparently chicks were not accustomed on PG at levels higher than 5%. The findings was not agreeable with those obtained with rat2).Based on the findings of the preliminary experiment, dietary levels of all the glycols tested was kept constant at 5%, except two of them for which 2.5 or 3% was tested in bioassay of available energy6, 8), with 822 4-week-old chicks and 82 one-week-old chicks in total. Following results were obtained.1. It was unexpected that chicks can utilize 58% of gross energy of ethanediol (ethylene glycol, EG), i.e. 4.60kcal/g, which was reported to be toxic, without any ill signs in the appearance, except with significantly loose droppings of 83% of moisture comparing with 75% on control diet.2. Chicks can almost completely utilize the gross energy of 1, 2-PG, 5.68kcal/g, without any ill effect in the performance at dietary level of 5%.3. Chicks can almost completely utilize gross energy of 1, 3-buthanediol (1, 3-butylene glycol, 1, 3-BG), 6.44kcal/g, without any ill eflect at dietary level of 5%.4. 1, 4- and 2, 3-BG depress growth rate and appetite of chicks. It will be hopeless to use them as energy source for poultry feed.5. Chicks can utilize about 35% of gross energy of diethylene glycol but not utilize that of dimer of PG and trimers and tetramers of both EG and PG. Polymers of PG with average molecular weight of 2, 000 and 3, 000 were both inert for chicks. It was suggested that chicks has no enzyme or ehzymes to cleave the ether-bond of the polymers of EG and PG.

Lactation and suckling in relation to early growth of the southern elephant seal, Mirounga leonina (L.)

The growth rate of elephant seal pups during the suckling period is shown to be lower at Macquarie I. than at the Falkland Is. Dependencies. Earlier initiation of suckling and lower suckling frequency occurs in the more rapidly growing Falkland Is. seal pups. The analyses of the milk samples collected from Macquarie I. elephant seal cows at different stages of lactation are reported, and a striking difference in milk composition at the different stages is noted. An attempt to determine quantitatively the milk production of the elephant seal is described, and the inaccuracies of the methods used are discussed, with comments on how a better estimate could be obtained. It is concluded that the principal cause of depressed growth rate of elephant seal pups at Macquarie I. is disturbance within the harems. This disturbance has been alleviated to some extent at the Falkland Is. due to alteration in the structure of the population by long-term sealing operations. Indicative of disturbance within the harems at Macquarie I. were the high incidence of injury noted during dissection of 54 seal pups, the delayed initiation of sucking in new-born pups, and the higher frequency of sucking by pups.

Effect of mineral oil ingestion on growth and liver lipid composition in the rat.

SummaryThe effect of paraffin, transformer, spindle and the respective oxidized oils on growth rate and percentage composition of liver lipid in rats was studied for a period of 4 weeks. The results indicated that transformer, spindle, oxidized transformer and oxidized spindle oils significantly depressed growth rate in rats. A decreased percentage in phospholipids and an increased percentage in triglycerides was noted in the liver lipids from these animals. Paraffin oil and oxidized paraffin oils decreased the growth rate per week slightly; there was no change in the percentage of the various lipid classes in the liver in these animals. Increased levels of palmitoleic acid were found in the cholesterol esters fraction of rats fed paraffin, transformer, oxidized paraffin and transformer oils. More oleic acid was detected in free fatty acids and triglycerides of rats fed transformer, spindle, oxidized paraffin, transformer and spindle oils.

Effect of 2- N-mono- and 2- N-diethylaminoethanol on normal and choline-deficient rats

In rats, the acute oral LD 50 value of neutralized 2- N-monoethylaminoethanol (MEAE) was found to be 1.0 (0.68–1.35) g/kg. The acute oral toxicity of MEAE, but not that of 2- N-diethylaminoethanol (DEAE) could be largely reversed by simultaneous or subsequent ingestion of choline. MEAE partially prevented the development of fatty liver in choline-deficient rats. No reversal of depressed growth rate was noted in choline-deficient animals whose diets were supplemented with either MEAE or DEAE.

Effect of feeding 5 per cent l-phenylalanine to young chicks

1. 1. A diet containing a 5 per cent excess of phenylalanine was fed to day-old and 4-week-old chicks for periods of four weeks. 2. 2. The following deficits were noted: depressed feed efficiency, depressed growth rate, malformation of hock joint and toes, poor motor coordination, discoloration of shank and face, crop enlargement, rough feather development, reduced hemoglobin content of the blood and, in general, retarded growth and development in all physical parameters. 3. 3. Complete remission of all somatic deficits except spleen weight was obtained within four weeks by supplying the animals with a normal diet.

Relationship of Fractions of Soybeans and a Crystalline Soybean Trypsin Inhibitor to the Effects of Feeding Unheated Soybean Meal to Chicks

Serveral experiments were conducted to study the effects of fractions isolated from unheated soybean meal on pancreatic hypertrophy, fat absorption, utilization of non-fat components of the diet, and growth rate of chicks, to determine whether these measurements were affected by specific components of the meal. Unheated soybean meal was fractionated into a water-insoluble residue, pH 4.4. insoluble proteins, salts insoluble at pH 8, and whey proteins recovered by dialysis and lyophilization of the portion of the meal soluble at pH 4.4. When fed to chicks at levels of 1.3 to 1.9% of the diet, the soybean whey proteins markedly depressed growth rate, caused pancreatic hypertrophy, reduced fat absorption, and lowered metabolizable energy value of the diet. Whey proteins were batch separated on DEAE cellulose into 2 fractions, one high in hemagglutinin activity and one high in trypsin inhibitor activity. Neither fraction when fed alone affected growth rate, fat absorption or metabolizable energy value of the diet to the same extent as a combination of the 2 fractions. A diet containing 0.6% of a crystalline Kunitz soybean trypsin inhibitor depressed growth rate of chicks and metabolizable energy value of the diet, caused pancreatic hypertrophy, but had no other undesirable effects. These experiments suggest that multiple factors are present in unheated soybean meal which cause the detrimental effects observed.

Delayed mortality in adult chickens exposed to 1 atmosphere oxygen.

THE growing chick (2–7-week-old White Leghorn) is markedly resistant to the usually lethal effects of 100 per cent oxygen at one atmosphere (OAP), exhibiting only a depressed growth rate and feed intake1. It has been theorized that the different anatomy of the avian respiratory system might enhance resistance to a toxic agent believed to act primarily on the lungs. However, the young of several mammalian species are more resistant to the toxic action of OAP than the adults2. The question of whether the chicks' mild reaction to OAP was a function of its young age or unique anatomy could not be decided from the literature, which, so far as the domestic fowl is concerned, appears to be limited to a report on three adults3. Therefore, further tests involving the exposures of mature White Leghorns to OAP were undertaken.

Lens development: III. Relationship between the growth of the lens and the growth of the outer eye coat

This investigation explored the relationships which exist between the growth of the lens and the growth of the outer eye coat (cornea plus sclera) during the development of the chick embryo eye. By introducing one end of a minute glass drainage tube through the eye wall at 4 days of incubation, vitreous substance was allowed to escape as it formed. Intubated eyes increased in overall size at rates which ranged from normal to very slow. Consequently, by 16 days of incubation the group of intubated eyes had achieved widely differing sizes, despite the fact that they were all of the same chronological age. In the first of two experiments, the total protein nitrogen per eye wall in the intubated eyes was proportional to the size which the eye had achieved by 16 days of incubation. This indicates that the smaller size of the outer eye coat reflected a depressed growth rate, and not simply a different spatial distribution of the same amount of substance, Furthermore, within the outer eye coat the growth rates of both the cellular portion, which was measured as total deoxyribonucleic acid per outer eye wall, and the extracellular portion, which was measured as hydroxyproline present in collagen per eye wall, were depressed. However, the amount of extracellular substance produced per cell (estimated as collagen/DNA) was constant regardless of the rate of growth of the outer eye wall. These results suggest that the enlarging vitreous body regulated the growth of the outer coat of the eye by controlling the number of cells in this layer rather than by controlling the amount of extracellular matrix produced by each cell. In a second experiment, similar to the first, the increase in size and the change in shape of lenses in intubated eyes were measured as a function of age. Such lenses grew normally and maintained normal shapes as development proceeded. Thus the growth of the lens was uncoupled from the growth of the outer eye coat. While the outer coat of the eye did not control the growth of the lens to harmonize with its own growth, the lens appeared to exert an indirect control over the growth of the outer coat of the eye in the following manner. Previous work had established that the lens must be present for vitreous substance to accumulate. The enlarging vitreous body, in its turn, helped control the growth of the outer coat of the eye.

The Influence of Different Environmental Temperatures on Immature Fowl

THE accepted practice for growing young chicks has been to provide adequate heat within a temperature range that enables the chick to select its own “comfort zone”. Consequently very few studies on temperature tolerances of young birds have been conducted. Modern brooding temperature procedures are based on a series of studies by Barott and Pringle (1947, 1949, 1950).Numerous studies have shown that high environmental temperature depressed growth rate. Ota and Garver (1954) grew chicks in environmental temperatures of 19.4°C. and 30°C. from one day to nine weeks of age. The temperature under the hover was set at 35°C. and reduced 2.8°C.per week until the air temperature of the respective chamber was reached. The average body weight of the birds grown in the cooler environment was higher. Prince et al. (1961) subjected chicks to environmental temperatures of 7.2°, 12.8°, 18.3° and 24°C. from four to eight weeks of age. The…

Responses of Holstein Calves Raised on Limited Milk to Simulated Louisiana Summer Climatic Conditions

One group of five female and one group of four male newborn Holstein calves were subjected to air temperatures cycling diurnally between 75 and 95F and constant vapor pressure of 20mm Hg in a psychrometric chamber and two similar groups were subjected to ambient winter climatic conditions in an open-air calf barn until ages ranging from 60 to 90 days. During the post-experimental period from 91 to 150 days of age, all calves were placed together in a cool environment and group fed.Conditions imposed on the experimental calves were stressful and resulted in greatly depressed growth rate, which continued during the post-experimental period. Limited water allowances made the thermal stress more acute. Consumption of concentrates and hay was reduced in the experimental calves and the digestibilities of dry matter, energy, crude protein, and total digestible nutrients were not significantly lower than in the control calves.Faster respiration rates and higher rectal temperatures and lower hematocrit and hemoglobin levels were found in the experimental calves as compared to those of the control calves. No direct effects of heat exposure on plasma carotenoid or vitamin A levels nor on serum protein concentration were evident. There was some indication that heat stress decreased serum α-globulin.

Interrelationships between Dietary Levels of Sodium, Chlorine and Potassium

A series of experiments was conducted on the dietary relationship of the cations, sodium and potassium, and the anions, chloride and sulfate. The data showed that excesses of dietary chloride or sulfate ions supplied as glutamic acid hydrochloride, calcium chloride or calcium sulfate markedly depressed growth rate of chicks unless these anions were balanced with equimolar levels of sodium or potassium supplied in the diet with a metabolizable anion such as glutamate or carbonate. Excess sodium supplied as sodium glutamate was also detrimental unless a high level of chloride in one of the above forms was also present. Chicks tolerated excesses of potassium better than excesses of sodium. These experiments provide a probable explanation of many discrepant results reported in the literature on the dietary requirements of chicks and rats for sodium and potassium.

PHYTIC ACID STUDIES.

SummaryRelative tendency of some metals to complex with phytic acid, and the influence of sodium phytate on the availability of zinc in chicks were studied. Of the metals studied, zinc appeared to form the most stable complex with phytic acid in the physiological pH ranges. Addition of sodium phytate (0.25%) to a low-zinc chick diet depressed growth rate presumably by binding zinc and rendering the element less available for growth. Therefore, the greater tendency exhibited by zinc to form a complex with phytic acid near physiological pH ranges would possibly explain the adverse effect of phytic acid on zinc metabolism.

Studies on Chloride Deficiency in Chicks

Chloride deficiency was produced by feeding young chicks a purified diet which contained 190 mg Cl/kg diet. Chicks fed this diet exhibited extremely poor growth rate, high mortality, hemoconcentration, dehydration and a reduced blood chloride. In addition, deficient chicks showed nervous symptoms which appeared to be characteristic for chloride deficiency. Supplementation of the basal diet with 1200 mg chloride resulted in optimal growth rate and prevented the occurrence of deficiency symptoms. Although excess sodium and potassium did not affect the growth rate of deficient chicks, these cations increased the incidence of mortality and nervous symptoms. Bromide (676 to 1352 mg/kg) added to the basal diet partially counteracted most of the symptoms of chloride deficiency except the nervous symptoms. Higher levels of bromide were of no additional value. Iodide (537 to 1074 mg/kg) depressed growth rate but did not interfere with the typical chloride growth response curve. However, the data on incidence of mortality and nervous symptoms suggested an interaction between iodide and chloride. Fluoride (268 mg/kg) had no effect on the course of chloride deficiency.

The biological effects of food additives. I.—Nisin

AbstractNisin has been administered to rats at three dosage levels in cheese, in which it had been prepared in situ, and at two dosage levels as the commercial product (Meganisin) added to a basal diet.The effects of nisin have been assessed by examining the rate of body‐weight gain, the food intake, the reproductive performance, survival of young, the haematological picture, organ weights, mortality rate and gross and microscopical appearance of the organs. In addition, gastrointestinal, renal and hepatic functions have been studied.Special attention has been paid to possible antimetabolic and nephrotoxic actions of nisin. The sensitising action of nisin has been investigated in the guinea‐pig.Although nisin appeared to depress growth rate of male rats in one test at only 14 times the possible human dosage level, normal growth was found in other tests at 1400 times this dosage level. Depression of growth rate was associated with reduced food intake. There was no other consistently significant finding and it has been concluded that nisin is a safe substance for use in food at the level of treatment proposed.

Colour and Density of Light and Broiler Performance

IT has been shown that some form of artificial lighting is necessary to achieve the most rapid gains of weight in broilers1. With controlled environments, light intensities of 0.1–6.0 ft.-c. gave equally good growth-rates in broiler chicks during the first eighteen days, and 12.0–24.0 ft.-c. produced slightly depressed growth-rates during this period2. A field scale survey has noted that in many broiler houses in Britain the light intensity is maintained at 0.05–0.20 ft.-c. as a control measure for the prevention of cannibalism3. An experiment is being conducted which has already compared three types of continuous lighting in relation to broiler performance.