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Adenovirus (Ad) has been used in vivo and in vitro as a vector to carry a foreign gene for efficient gene delivery into various cell types and tissues of animals. The aim of the current study was to evaluate the Ad delivery system in primary avian cells. Primary cells isolated from the embryonic pectoralis major muscles of the chicken and quail were cultured and incubated with human recombinant Ad serotype 5 (Ad5) containing sequences encoding either the green fluorescence protein (GFP) gene alone, as a tracking marker, or both GFP and murine 3-hydroxyisobutyryl-CoA hydrolase (mHIBCH) as a target gene. The fluorescent GFP images showed the successful delivery of a target gene using Ad5 in the primary avian cultured cells. In addition, immunostaining of the myosin heavy chain (MyHC) in these cells indicated that a large population of the cells was myogenic. Colocalization of GFP-positive cells with MyHC staining was mostly found in MyHC-negative cells, indicating successful delivery of Ad5 into a large population of mononucleated cells. Furthermore, the current fluorescence study detected the dual expression of GFP and mHIBCH protein in GFP-positive cells. Finally, Western blot analysis confirmed that the Ad-mediated expression of mHIBCH protein was specific in primary cultures of avian myogenic cells and that the mHIBCH protein expression was continued for 15 d after infection in chicken primary cells. These data demonstrate that Ad5 is a feasible tool to express foreign genes in primary cultured cells of avian species, providing a new approach to study the function of genes of interest in muscle development and metabolism.

Delta-like protein 1 (DLK1) has been implicated in the muscle hypertrophy observed in DLK1 transgenic mice, callipyge sheep, and mouse paternal uniparental disomy 12 and human paternal uniparental disomy 14 syndromes. The current study was aimed to determine chicken DLK1 (gDLK1) mRNA expression during primary muscle cell differentiation and during muscle regeneration after cold injury and to compare gDLK1 mRNA expression during skeletal muscle development in layers and broilers. In chicken primary muscle cell culture, gDLK1 mRNA expression was significantly increased from 12 to 48 h (Por = 0.05) when the nascent myotubes were actively formed at d 2 to 3. Myogenin, a late myogenic marker gene, mRNA expression peaked at 36 to 48 h. Myogenic differentiation 1 (MyoD) and paired box gene 7 (Pax7), early myogenic marker genes, mRNA expression gradually decreased during myogenic differentiation. During muscle regeneration, the expression of MyoD and Pax7 peaked at d 2 (Por = 0.05), and myogenin mRNA expression peaked at d 4 (Por = 0.05). The induction of gDLK1 gene appeared between d 7 to 10 postinjury (Por = 0.05) when myotubes were actively formed as also demonstrated in histological sections. The expression of gDLK1 was slowly downregulated to the control levels at d 14 when the damaged muscle appeared nearly healed. These data suggest that gDLK1 may be involved in the late myogenic stages of primary muscle cell differentiation and muscle regeneration. The gDLK1 mRNA in the muscle tissues was very abundant at embryonic ages but decreased after hatching in both broiler and layer chickens. Compared with layers, broiler muscle at embryonic d 13 had a 3-fold greater expression of DLK1 (Por = 0.01). In addition, the gDLK1 mRNA expression at d 1, 11, and 33 post-hatch was significantly higher in broilers than layers (Por = 0.05). Therefore, the relatively greater expression of the gDLK1 gene in muscles of broilers compared with layers suggests that gDLK1 may serve as a new selection marker for high muscle growth in chickens. These findings may provide new insight into chicken muscle development and regeneration.

Broiler chickens were used to alter the partitioning of ME between maintenance and production. They were fed amounts of feed that ranged between ad libitum and 75 to 80% ad libitum each day from a BW of 1.1 to 2.2 kg. The experiment was done with 2 strains of broilers, both sexes, and 2 forms of feed (mash or pellets). Data were collected to determine live performance, digestibility of the feed, and carcass composition. The daily amount of feed did not affect the ME of the feed, but broilers fed limited amounts of feed gained less BW per day and had a larger feed:gain ratio. For most measurements, strain of broiler, sex, and form of feed also were significant factors. Because broilers that gained BW more slowly required more days to gain 1.1 kg and more feed during that time, a larger proportion of the energy was used for maintenance. The net energy theory proposes that heat increment, net energy for maintenance, and net energy for production are constants for a feed ingredient or feed. Results from the present research did not support the net energy theory. A different model was proposed that used ME as the basis for energy partitioning. Amounts of feed or energy per day had no effect on the ME content of the feed; however, amounts of energy consumed per day had dramatic effects on the proportion of the ME from each gram of feed that was used for maintenance, product, or heat increment. A model was developed that showed these effects and the feed:gain ratio over a wide range of daily energy intake.

An experiment was designed to test the ability of broiler chickens to equalize daily energy intake when proximate components of the diet were changed. A factorial arrangement was used to test effects of protein, fat, and fiber content in the diet. The simplest diet contained only corn and soybean meal to provide energy and protein. Protein contents were calculated to be 16.4, 18.2, and 20.0%, with added protein from a combination of corn gluten meal, fish meal, and peanut meal. Hydrolyzed fat was added at 0, 2.5, 5.0, and 7.5% of the diets. A combination of alfalfa meal, oats, and wheat middlings was used to increase the fiber of the corn soy diet by approximately 2 and 4%. The 36 combinations were fed as mash. In addition, 8 of the diets were fed as pellets. All diets were fed for 12 d from the time broilers reached approximately 1.2 kg. A total excreta collection was used to determine ME, and carcass analysis provided fat and energy content. When fed mash, only sex had a significant effect on grams of feed eaten per day. Sex and dietary fat content affected gain per day. Sex, fat, and fiber altered the kcal of ME eaten per day. Broilers fed 5% added fat ate approximately 10% more energy per day than those fed no added fat, and broilers fed 4% added fiber ate approximately 20% less ME than those fed no added fiber. A comparison of results from mash and pellets showed that only sex and form affected gain per day, feed per day, and kilocalories of ME eaten per day. For the mash and pellets, protein, fat, fiber, and several interactions affected the ME per gram; however, the ME per gram was similar for pellets and mash. The results suggest that the diet composition and form have a significant effect on the energy intake of broiler chickens.

Hens fed diets with 0.0, 7.5, 15.0, 30.0, 60.0 and 120.0 mg supplemental α-tocopherol/kg feed produced egg yolks with 25, 30, 35, 45, 50 and 75 μg/g yolk, respectively. The correlation coefficient between dietary α-tocopherol (mg/kg diet) and egg yolk α-tocopherol (μg/g egg yolk) after 28 days feeding was 0.99. The supplemented dietary α-tocopherol had an effect on the α-tocopherol in egg yolk (P

Magnum and isthmus morphologic characteristics (surface epithelium height, fold height and diameter, and periodic acid-Schiff-positive area and surface epithelium cells) of stained 6-micron tissue sections were measured by light microscopy, with data acquisition using a digitizing tablet interfaced to a microscope and to a personal computer with morphometric-dimensional software. Tissues were obtained from Leghorn layers in two separate experiments in which production of eggs with low and high Haugh unit (HU) values was induced by either genetic selection or by feeding V. Eggs produced by these hens had HU differences between the high and low groups of 11 to 14 units (both experiments, P = .0001) and had a greater volume of thick albumen fraction in high-HU groups (both experiments, P = .0001). The computer software-integrated digitizing system enabled rapid measurements of multiple characteristics. In the genetic lines, higher magnum fold height and magnum and isthmus surface epithelium height were detected at moderate significance (all at P.05) in the tissues of the layers producing high-HU eggs than in tissues from the low-HU line. Other morphologic variables were not different between genetic lines. In response to feeding V, none of the morphological characteristics were affected, although magnum fold height approached difference at P.07. Based on the observations in these two experiments, magnum fold height may be a further important factor related to egg albumen condition, in addition to surface epithelium height. It appears, however, that layers producing eggs of considerably different HU values, due in these experiments to genetics or V feeding, can have magnum or isthmus morphological characteristics that are indistinguishable, or only moderately different, as detected by integrated digitizing technology.

The development of V toxicity was followed over a 28-d period in 25-wk-old Leghorn layers fed 20 mg ammonium metavanadate/kg diet (Days 1 to 14) followed by 30 mg/kg diet (Days 15 to 28). Then, over a second 28-d period, the responses to V and supplemental ascorbic acid (AA) fed at 500 or 1,000 mg/kg diet (Days 29 to 42) followed by 1,500 or 3,000 mg/kg diet (Days 43 to 56) were examined. Feed consumption, egg weight, Haugh units (HU), and BW measurements indicated that the response to V was multifactorial, but of differing intensities and time-frames for the variables. Haugh units were lowered rapidly (3 d, P < .05) in response to V feeding, but HU values decreased only slightly when dietary V was increased to 30 mg/kg. In contrast, egg production was decreased moderately by 20 mg V/kg and a considerable further reduction in egg production resulted from increasing the V to 30 mg/kg. Ascorbic acid supplementation differentially affected these responses: BW, egg production, and egg weight were improved significantly in the V-fed group receiving an AA supplement, as compared with those fed V only. Haugh unit values, however, were not improved by AA supplementation in groups receiving V. Foam functional properties, which also were changed by V feeding, were not corrected by AA feeding. The results suggest that the toxic effects of V are mediated through more than one physiological mechanism. One mechanism, which includes negative effects on BW, egg production, and egg weight, is responsive to the additional reducing equivalents provided by supplemental AA. Another mechanism, which is apparent from the effect of V on egg HU values, is not ameliorated by AA supplementation after toxicity developed.

Various tissues of menhaden fish were analyzed for macro and micro minerals. Tissues selected were gill, heart, intestine, kidney, liver, muscle, spleen, and stomach. Phosphorus, calcium, magnesium, sodium, manganese, and zinc were found to be most concentrated in the gill. Potassium, iron, and boron were least concentrated in the gill. Liver contained the highest concentration of copper, selenium and boron. The stomach was the highest in potassium and lowest in phosphorus. Sodium and selenium concentrations were lowest in the muscle. Mercury concentrations were approximately 2 mg/g dry matter in all tissues

1. An experiment was designed to test if the lysine requirement, expressed as g lysine/kg CP, was the same for several protein sources. 2. Groundnut meal, groundnut meal adjusted with indispensable amino acids or sesame meal supplied the dietary CP at 180 g/kg diet. Increments of lysine (1.5 g/kg diet) were added to each of these diets. 3. The gain, food intake and food efficiency responses of broiler chicks were analysed using a quadratic equation and a two-slope method. An estimate of lysine requirements was also obtained from a survey of college students. 4. The different methods produced widely different estimates of lysine requirement. 5. The average lysine requirement was estimated at 50.1 g lysine/kg CP for groundnut meal, 61.7 for adjusted groundnut meal and 54.9 for sesame meal. 6. Reasons for the effect of statistical analysis and protein source on lysine requirement are discussed.

Because dietary nitrogen intake affects nitrogen content in manure, diet management has been recognized as a means to reduce ammonia emissions from poultry operations. The objectives of the present research were 1) to determine the extent to which the CP content of laying diets can be reduced, based on performance criteria, and 2) to determine how ash:nitrogen ratios of manure, eggs, and hens are affected by dietary protein changes. Egg-type hens were fed equal daily amounts of essential amino acids in diets that provided 13, 15, or 17 g of protein/d. Each diet was fed to 20 hens, with 2 hens/cage. The planned digestible lysine intake was 0.71 g/hen per day. Ratios of other digestible amino acids to lysine were methionine plus cysteine, 0.83; threonine, 0.68; and isoleucine, 0.94. The experiment began when hens were 29 wk old and continued until they were 57 wk old. Egg production averaged approximately 90%, and daily protein intake caused no effects on egg production or grams of egg per hen per day. Feed intake was higher for hens fed 13 g of protein than for hens in the other 2 treatments (P < 0.01). Average feed intake for the experiment was approximately 95 g/d. Composition of the eggs was not affected by protein intake. Average values were DM, 30.5%; ash, 31.0% of DM; and nitrogen, 6.31% of DM. The average manure DM production was 25.9 g/hen per day, with an ash content of 25.5% of DM. Manure nitrogen content ranged from 3.98% of DM for hens fed 13 g of protein to 5.68% for those fed 17 g of protein (P < 0.01). A method is outlined that uses the analysis of fresh manure and manure leaving the poultry operation to estimate the loss of nitrogen as ammonia.

1. An experiment was designed to determine if decreasing excess amino acids in the diets of chicks would improve metabolic efficiency, as indicated by growth rate and food efficiency. 2. Semi-purified diets were fed with crude protein contents of 180 or 230 g/kg. The sources of protein were maize gluten meal, groundnut meal, sesame meal or soya-bean meal. Crystalline amino acids were supplemented to meet all amino acid requirements. 3. The dietary crude protein content had no statistically significant effect on weight gain or food consumption. The probability that the higher protein improved gain per food was 0.06. Protein source had a significant effect on all the responses measured. 4. Decreased concentrations of excess amino acids in chick diets had no favourable effects on weight gain or gain per food. Lower protein diets were more expensive per unit of gain.

Increasing the breakdown of stored fat in adipose tissue leads to reducing fat content, enhancing feed efficiency and, consequently, decreasing the production cost of poultry. The processes of lipolysis are not completely understood, and the proteins involved in this process need to be identified. An adipose triglyceride lipase (ATGL), recently identified in several species, has not been studied in avian species. We have cloned the full-length coding sequences of ATGL cDNA for the chicken, turkey, and quail. Sequence comparisons among mammals and these avian species showed that the avian ATGL have 2 conserved domains, the patatin domain and the hydrophobic domain. The patatin domain contains lipase activity, and the hydrophobic domain exhibits lipid droplet binding. The high levels of chicken, turkey, and quail ATGL mRNA and protein are exclusively found in subcutaneous and abdominal adipose tissues. In addition, chicken ATGL (gATGL) is mainly expressed in the fractionated adipocytes compared with stromal-vascular cells that mostly contain preadipocytes (P < 0.001). Furthermore, ontogeny of gATGL mRNA and protein expression in adipose tissue showed induction of gATGL immediately after hatching before access to food (P < 0.05), suggesting that an energy deficit due to posthatching starvation may increase breakdown of stored fat via increasing gATGL expression in adipose tissue. Our studies showed that expression of the chicken ATGL is adipose specific and regulated developmentally, suggesting that a possible modulation of ATGL expression would regulate fat deposition in avian species.

Two feed additives were tested for their ability to improve eggshell quality. One was Shell-Developer, containing approximately 60% NaHCO3, and the other was Ethacal, a sodium aluminosilicate. Both feed additives were fed to three commercial strains of hens. The first trial began in early summer and lasted 28 days, the hens having been in production for 56 wk at the start of the trial. Ethacal was fed at a rate of .75% of the diet. Shell-Developer was fed at a rate of 1.25% of the diet for 7 days, .625% for the next 7 days, and .3125% for the last 14 days. The second trial ran for 56 days in autumn, utilizing the same hens after a forced rest and approximately 2 mo of production. The addition of Shell-Developer had no positive effects at any time on any of the characteristics measured. Ethacal had a negative effect on the rate of egg production and egg weight during the last 28 days of Trial 2. Ethacal also decreased feed consumption in three of the five data collection periods tested. In Trial 2 Ethacal significantly improved egg specific gravity and also improved the percentage of eggs with a specific gravity of at least 1.08. The negative effect of Ethacal on egg production and egg weight is postulated to be due to its negative effect on phosphorus nutrition.

Delta-like protein 1 (DLK1) is involved in adipose and muscle development as shown by the reduction of fat mass in DLK1 transgenic mice and in muscle hypertrophy of callipyge sheep. However, no study on DLK1 has been investigated in avian species. Cloning and sequencing of a full length of chicken DLK1 (gDLK1) complementary DNA revealed that gDLK1 contains a total of 1,161 bp, encoding 386 amino ac- ids. The similarity of gDLK1 nucleotide and protein sequences was over 50% compared with other mam- malian species. In addition, chickens only express one full length of gDLK1 in various tissues at different ages without the alternative splicing variants of DLK1 found in mammalian species. This suggests that the full-length form of gDLK1 may be sufficient for normal develop- ment in the chicken. In adipose tissue, the gDLK1 gene was highly expressed in preadipocytes as compared with adipocytes (P < 0.05), whereas expression levels of adipogenic marker genes such as stearoyl-coenzyme A desaturase 1 (SCD-1) and fatty acid binding protein 4 (FABP4) were higher in mature adipocytes than in preadipocytes (P < 0.05 and P < 0.01, respectively). Expression of gDLK1 in adipose tissue tends to de- crease with age. The expression of gDLK1 gene in the pectoralis major muscle was significantly higher in 13- and 17-d-old embryos (P < 0.05), decreased in 1- and 5-d-old chicks (P < 0.05), and further decreased in 11- and 33-d-old chickens (P < 0.05). This expression pat- tern of gDLK1 was very similar to the expression pat- terns of myogenin and Pax7 genes, suggesting a close association with myogenic activities. In conclusion, the developmental regulation of gDLK1 expression might play an important role in the early stages of adipose and muscle tissue development.

Feather meal contains three sulfur amino acids: cystine, lanthionine, and methionine. Procedures were investigated to determine the best conditions for quantitating the sulfur amino acids in feather meal. To separate the sulfur amino acids by ion exchange chromatography, an elution system using 100 mM citrate buffer at pH 3.5 was found to be acceptable. Performic acid oxidation followed by acid hydrolysis oxidized lanthionine but also cleaved a substantial portion to form cysteic acid and an unknown compound. This result suggested that samples containing lanthionine should not be oxidized before hydrolysis. The effects of pH and of pressure during feather processing were determined. The pH was 5,7, or 9; and the steam pressures were 207, 276, or 345 kPa for 30 min. Increasing the pH or pressure increased the percentage of the protein that was pepsin digestible. As the pepsin digestibility increased, the cystine content of the feather meal decreased and mat of lanthionine increased. The experimental feather meals were included at 2.5% in a diet low in sulfur amino acids. The preparation of the feather meal had no effect on the feed:gain ratio or on weight gains by the chicks.

Mature White Leghorn roosters that were intact or cecectomized were used to determine the ME of a diet. Seven intact and 7 cecectomized roosters were fasted for 3 d, with total excreta collection on d 2 and 3. Approximately 1 wk after completion of the trial, the same roosters were force-fed 28 g of a diet that was 85% corn and 15% soybean meal after a 1-d fast. Excreta were collected from d 2 and 3 and dried. There was no difference in the energy and nitrogen excreted by intact and cecectomized roosters when they were fasted for 3 d. The energy and nitrogen excreted by cecectomized roosters were greater than by intact roosters when they were fed the test diet. As a result, the AME, TME, AMEn, and TMEn were all larger from intact roosters than from cecectomized roosters. Our results suggest that intact roosters should be used to determine the energy content of ingredients that will be fed to commercial flocks.

Five sources of corn distillers dried grains with solubles (DDGS), which varied in darkness of color, were collected from several processing plants in the Midwestern United States. Sources of DDGS were analyzed for their amino acid and energy contents, measured for color score, and evaluated for TMEn, apparent amino acid digestibility, and true amino acid digestibility. A precision-fed rooster assay was used, in which each DDGS sample was tube fed (25 g) to adult cecectomized roosters, and the excreta were collected for 48 h. The experiment was conducted as a randomized complete block design with 8 replicates. Seven adult roosters (averaging 75 wk of age) were used in each period, with 5 fed the DDGS sources and 2 fasted to estimate basal endogenous amino acid losses. One source (no. 5) was the darkest, 2 sources (no. 2 and 4) were light, whereas 2 other sources (no. 1 and 3) were intermediate in color as measured by a colorimeter. Total lysine content of the DDGS sources ranged from 0.48 to 0.76%, with the lowest lysine content in the darkest DDGS source. Apparent and true lysine digestibility was approximately 30 and 15 percentage units lower (P < 0.05), respectively, in the dark-colored source (no. 5) than in the other 4 sources. Average apparent and true digestibility of the essential amino acids were 10 and 8 percentage units lower (P < 0.05), respectively, in source 5 than the other 4 sources. The TMEn content of the 5 DDGS sources was also lower (P < 0.05) in the darkest DDGS (no. 5). Our results suggest that when the color score of a DDGS source, as measured by a colorimeter, reached a certain threshold (lightness between 28 and 34), amino acid availability and true metabolizable energy content may be reduced. This reduction was particularly evident for lysine, which had the lowest digestibility in the darkest DDGS source. These results suggest that dark-colored DDGS may have been overheated during drying, causing Maillard reactions to be more extensive and resulting in a lowered total lysine content, lysine digestibility, and TMEn content.

The recovery of broiler chickens experiencing skeletal muscle myopathy caused by a selenium deficiency was compared with control broiler chickens in an age matched study by ultrastructural analysis of the pectoralis major (PM) muscle and examination of the temporal expression of the developmental fast skeletal myosin heavy chain (MyHC) isoforms. Selenium-deficient chicks showing signs of exudative diathesis (ED) were injected subcutaneously with sodium selenite in water and allowed to recover. At 0, 2, 5, 10, 20, and 30 d after selenium injection, a sample of the PM muscle was removed from selenium-deficient and control chicks for analysis. Ultrastructural analysis revealed vacuolization in the PM of selenium-deficient chicks with little or no visible damage to the sarcomere. Relative amounts of chicken ventricular, embryonic, neonatal, and adult fast skeletal MyHC isoforms were determined using chicken fast skeletal MyHC isoform specific monoclonal antibodies. The temporal expression of the developmental MyHC isoforms was similar in all chickens (P > 0.05). There was no expression of chicken ventricular MyHC observed in the PM of either group. These results indicate that chicken fast muscle recovering from exudative diathetic myopathy does not use the same pathways as chicken skeletal fast muscle regenerating from physical or toxic injury in which temporal expression of the MyHC isoforms is initially predominantly ventricular, then predominantly embryonic, neonatal, and finally predominantly adult developmental MyHC isoform.

A flock of breeding ring-necked pheasants received feed with a high selenium content. Within 4 days of eating the toxic feed, the rate of egg production began to decrease, and bird aggression increased. Approximately 12% of the hens died within a week. Necropsy of the hens revealed colorless fluid around the heart and a friable, but otherwise normal, liver. The rapid onset of the problem and signs noted at necropsy suggested toxicosis. Based on analysis, the feed contained 9.3 ppm of selenium. Selenium toxicity was consistent with the histologic diagnosis of degenerative cardiomyopathy, vacuolar degeneration of hepatocytes, and centrilobular hepatic necrosis. After 8 days, the toxic feed was removed and replaced with fresh feed. Egg production, which had dropped to 50%, returned to normal within 10 days of feed replacement. Hatchability of eggs laid from days 8 to 14 after delivery of the toxic feed was 35%. Approximately 10% of the chicks that hatched had deformed beaks and abnormal eyes. Many of the chicks that died in the shell had deformities, bringing the total to more than 50% of all embryos that developed. The selenium content of eggs that had no embryonic development was 2.05 ppm. Hatchability of eggs laid from days 21 to 28 after the toxic feed was delivered was almost 80%, which was slightly lower than normal. The selenium content of these eggs was 0.30 ppm. These results show the rapid onset and correction of selenium toxicity and suggest that specific embryologic defects are diagnostic for selenium toxicity.

The major objective of this research was to develop equations to estimate BW and body composition using measurements taken with inexpensive instruments. We used five groups of chickens that were created with different genetic stocks and feeding programs. Four of the five groups were from broiler genetic stock, and one was from sex-linked heavy layers. The goal was to sample six males from each group when the group weight was 1.20, 1.75, and 2.30 kg. Each male was weighed and measured for back length, pelvis width, circumference, breast width, keel length, and abdominal skinfold thickness. A cloth tape measure, calipers, and skinfold calipers were used for measurement. Chickens were scanned for total body electrical conductivity (TOBEC) before being euthanized and frozen. Six females were selected at weights similar to those for males and were measured in the same way. Each whole chicken was ground, and a portion of ground material of each was used to measure water, fat, ash, and energy content. Multiple linear regression was used to estimate BW from body measurements. The best single measurement was pelvis width, with an R2 = 0.67. Inclusion of three body measurements in an equation resulted in R2 = 0.78 and the following equation: BW (g) = -930.0 + 68.5 (breast, cm) + 48.5 (circumference, cm) + 62.8 (pelvis, cm). The best single measurement to estimate body fat was abdominal skinfold thickness, expressed as a natural logarithm. Inclusion of weight and skinfold thickness resulted in R2 = 0.63 for body fat according to the following equation: fat (%) = 24.83 + 6.75 (skinfold, ln cm) - 3.87 (wt, kg). Inclusion of the result of TOBEC and the effect of sex improved the R2 to 0.78 for body fat. Regression analysis was used to develop additional equations, based on fat, to estimate water and energy contents of the body. The body water content (%) = 72.1 - 0.60 (body fat, %), and body energy (kcal/g) = 1.097 + 0.080 (body fat, %). The results of the present study indicated that the composition of a chicken's body could be estimated from the models that were developed.

The objective of this study was to determine the relationship between the hepatic vitamin A (VitA) level and the pathologic changes in the oropharynx and esophagus of VitA-deficient turkeys. Study turkeys were provided with a diet sufficient (11,000 IU/kg) or deficient (2750 IU/kg) in VitA from 4 to 17 wk of age. Body weight, bacterial culture, and tissues from internal organs were collected at weekly intervals. VitA deficiency causes epithelial tissue damage in poultry. This epithelial damage was seen grossly as white plaques in the oropharynx and esophagus and histologically as squamous metaplasia of mucosal glands and keratinization of epithelium. No significant difference in body weights was seen among the groups. Moreover, no pathogenic bacteria was isolated during sampling periods. Liver VitA levels declined significantly after consumption of low VitA diet for 3 wk and were depleted after 5 wk. Squamous metaplasia due to VitA deficiency developed in the esophagus after 3 wk and in the oropharynx after 4 wk of consuming a VitA-deficient diet.

The effect of processing on the fat-soluble vitamin content of menhaden fish oil was studied. Menhaden oil samples were taken during various steps in commercial processing. Samples included a crude oil, a bleached oil, a refined oil, a refined then bleached oil, and a refined-bleached-deodorized-stabilized oil. The most processed oil had only about one-fifth as much vitamin A and vitamin D3 as the crude fish oil. Vitamin E levels were decreased by about half as a result of processing. Bleaching the oil with Fuller’s earth caused the major loss of retinols. Treating the fish oil with steam for several hours caused the major loss of vitamin D3.

1. An experiment was designed to test the response of broiler chicks (0-21 d) to dietary lysine concentration. Concentrations ranged from 9.9 to 14.4 g of lysine per kg diet when energy was 13.4 MJ ME/kg. 2. Estimates of the concentration of lysine needed for maximum body weights gain, food consumption and gain:food ratio were calculated using two statistical methods. An average of these estimates was 12.0 g lysine/kg diet to 21 d of age. 3. Chicks given 13.9 or 14.4 g lysine/kg diet were negatively affected by these concentrations. The decreases in average weight gain, food consumption and food efficiency were caused mainly by several chicks that developed severe leg problems and were much smaller than their pen mates. Chicks with no leg problems gained weight as rapidly as chicks receiving optimal amounts of lysine.

1. An experiment was designed to test if the lysine requirement, expressed as g lysine/kg CP, was the same for several protein sources. 2. Groundnut meal, groundnut meal adjusted with indispensable amino acids or sesame meal supplied the dietary CP at 180 g/kg diet. Increments of lysine (1.5 g/kg diet) were added to each of these diets. 3. The gain, food intake and food efficiency responses of broiler chicks were analysed using a quadratic equation and a two-slope method. An estimate of lysine requirements was also obtained from a survey of college students. 4. The different methods produced widely different estimates of lysine requirement. 5. The average lysine requirement was estimated at 50.1 g lysine/kg CP for groundnut meal, 61.7 for adjusted groundnut meal and 54.9 for sesame meal. 6. Reasons for the effect of statistical analysis and protein source on lysine requirement are discussed.

1. Chicks were fed on an isoleucine‐deficient diet, with 6 added concentrations of isoleucine to determine their isoleucine requirement and an additional 6 treatments were devised to determine their isoleucine requirement when dietary leucine and valine contents were increased. 2. The diet deficient in isoleucine contained 5.6 g/kg isoleucine with leucine and valine contents of 20.1 and 10.3 g/kg, respectively. Supplementation with leucine and valine increased these to 24.7 and 12.6 g/kg, respectively. 3. The isoleucine requirement was not affected by dietary leucine and valine contents in a diet with 13.4 MJ of ME per kg. Analysis of variance and Least Significant Difference of means indicated an isoleucine requirement of 7.2 g/kg. Non‐linear regression of the same data indicated an isoleucine requirement of 8.44 g/kg, based on weight gain, or 8.19 g/kg based on food efficiency. 4. Reasons for the failure to find an imbalancing effect of branched chain amino acids in practical diets are discussed.

SUMMARY. The objective of this study was to determine the relationship between the hepatic vitamin A (VitA) level and the pathologic changes in the oropharynx and esophagus of VitA-deficient turkeys. Study turkeys were provided with a diet sufficient (11,000 IU/ kg) or deficient (2750 IU/kg) in VitA from 4 to 17 wk of age. Body weight, bacterial culture, and tissues from internal organs were collected at weekly intervals. VitA deficiency causes epithelial tissue damage in poultry. This epithelial damage was seen grossly as white plaques in the oropharynx and esophagus and histologically as squamous metaplasia of mucosal glands and keratinization of epithelium. No significant difference in body weights was seen among the groups. Moreover, no pathogenic bacteria was isolated during sampling periods. Liver VitA levels declined significantly after consumption of low VitA diet for 3 wk and were depleted after 5 wk. Squamous metaplasia due to VitA deficiency developed in the esophagus after 3 wk and in the oropharynx after 4 wk of consuming a VitAdeficient diet.

An experiment was conducted to determine if selenium incorporation into egg proteins could be predicted on the basis of methionine or cystine content. Chickens in egg production were fed a basal diet or the basal diet supplemented with .2 or .4 ppm selenium from selenite or .2 or .4 ppm selenium from selenomethionine. Eggs were collected from each group after feeding the diet 18 days. All of the egg white proteins and yolk fractions prepared contained selenium, and all of them increased in selenium when more was fed. The increase in selenium in egg white proteins after feeding selenite did not appear to be related to the cystine content of the proteins. However, the increase in selenium in egg white proteins after feeding selenomethionine appeared to parallel the methionine content of the proteins. The selenium level of yolk fractions was more closely related to the cystine content. Livetin fractions had the highest selenium level, and low density fractions had the lowest. The data suggest that proteins synthesized in a tissue will have predictable amounts of selenium but that proteins from different tissues will have different patterns of selenium incorporation.

Total sulfur amino acid (TSAA) requirements and methionine and cystine combinations were investigated during two growth phases (0 to 21 days and 21 to 42 days) of broilers using practical-type diets. For the first growth phase (0 to 21 days), the basal diet contained .62% TSAA to which increasing increments of DL-methionine were added. Both overall growth and feed efficiency improved as methionine levels increased to a level of .82% TSAA. When methionine-cystine combinations were used with the same basal diet, it was found that cystine could supply 54% of the TSAA content. When expressed on a millimolar basis, the methionine requirement was 41%, while cystine could account for 59% of the TSAA's. During the second growth phase (21 to 42 days) a basal diet consisting of .52% TSAA was used along with DL-methionine supplements to determine sulfur amino acid requirements. The trend was towards a slight decrease in requirement from .82% during the first growth period, to between .70% and .76% TSAA in the diet, represented mainly by methionine. When sulfur amino acid combinations were used during this period it appeared the replacement value of cystine for methionine decreased to between 38 and 43% of the TSAA level. Results also suggested that a more efficient way to express the sulfur amino acid requirement may be on a mole per unit of feed basis.

Female chickens were fed graded levels of sodium selenite to determine at what level a selenium toxicity occurred. In the first experi ment a basal diet was supplemented with 0, 0.1, 1.0, 3.0, and 5.0 ppm of selenium. These levels had no effect on egg production, egg weight or fertility of the eggs. Hatchability of fertile eggs was significantly decreased by 5 ppm of dietary selenium. In the second experiment a basal diet was supplemented with 0, 5.0, 7.0, and 9.0 ppm of selenium. Egg weight and hatchability were significantly decreased by 7 and 9 ppm, and egg produc tion was decreased by 9 ppm of selenium in the diet. When selenite was added to the diet, there was a lag of 2 to 3 weeks before the selenium con tent of the egg reflected the content of the diet. As long as the selenium content of the diet remained the same, egg selenium remained the same. When selenium was no longer supplemented, egg selenium content de creased. Two weeks after cessation of selenite supplementation, egg sele nium was markedly reduced. Four weeks after cessation of selenite supple- . mentation, egg selenium levels approached those of birds fed a basal diet continuously. J. Nutr. 108: 1114-1120, 1978.

The effect of peroxide administration on chick growth, severity of exudative diathesis, and glutathione peroxidase activity was determined. Hydrogen peroxide reduced rate of growth and usually reduced glutathione peroxidase activity of liver and plasma. The severity of exudative diathesis was greatly influenced by dietary selenium level but we found little if any relationships of this disease to peroxide induced reductions in glutathione peroxidase activity. Neither ethoxyquin nor excess supplemental selenium were effective in reversing the peroxide toxicity. The effect of hydrogen peroxide in reducing enzyme activity was related to decreased selenium uptake and retention. Tertiary butyl peroxide administration caused a more serious depression in enzyme activity of liver than hydrogen peroxide. This organic peroxide caused a small, but non-significant, reduction in selenium retention.

Graded levels of raw soybeans replaced soybean meal as a protein source for laying hens. Only the hens fed 20% raw soybeans in the diet laid significantly fewer eggs than hens fed no raw soybeans. As the percentage of raw soybeans in the diet increased, there was a trend toward lower egg weight and body weight. Pancreas weights increased at an increasing rate as higher levels of raw soybeans were fed. In a second experiment soybean protein was provided by roasted or extruded soybeans, soybean meal, or soybean meal and raw soybeans. All treatments gave similar egg production. Egg weight and body weight were highest when hens were fed soybean meal with added oil. Performance was generally equal from all soybean sources. A computer formulated least cost laying diet showed that full fat soybeans would have been used at some times over the past three years if available.

Hens were fed a diet low in selenium made up mostly of corn and torula yeast. Egg production and hatchability increased significantly when selenium was supplemented, while the percentage of infertile eggs and early dead embryos decreased. Anemia also resulted from the deficiency. A total of .05 mg. selenium per kg. (.04 from the basal diet plus .01 supplemental) was adequate to prevent signs of deficiency in a diet which contained no supplemental vitamin E or antioxidant. In a second experiment the anemia was classified as macrocytic.

Soybeans from a single batch provided the soybean protein for a 280-day laying hen experiment, and the forms of soybeans fed were raw, flaked, as 44% protein soybean meal, or roasted. When the diets were adequate in sulfur amino acids, the form of soybean had no significant effect (P In a second study roasted soybeans were again compared to 44% protein soybean meal as a source of protein for laying hens. At equal dietary protein levels and comparable energy levels, hens fed either roasted soybeans or soybean meal plus oil produced equally well. No significant differences (P

An experiment was designed to determine if surgical bursectomy (Bx) of day-old chicks would alter the distribution or amount of selenium (Se) in chicken tissues. Sham-operated chicks and Bx chicks were fed a practical corn-soy diet with either no supplemented Se, selenite to supply .1 ppm Se, or selenomethionine to supply .1 ppm Se. Several chicks were killed at 10 and 21 days of age to determine tissue Se levels. At each time the remaining chicks were injected with sheep red blood cells (SRBC). The remaining chickens were killed at 56 days. Serum from Bx chicks caused no agglutination with SRBC, and the immunoglobulin content was decreased as compared to levels in serum of sham-operated chicks. The Se level of tissues increased as a result of time and Se supplementation (P less than .01). The Bx caused a small but significant (P less than .01) decrease in spleen Se level, but other tissue Se levels were not affected. The results suggest that the serum lymphocytes and immunoglobulins have only a passive function in Se metabolism and distribution in chickens.

Diets composed mostly of low selenium corn and torula yeast were fed to laying hens to produce a selenium and/or vitamin E deficiency. The basal diet was also supplemented with 101. U. of vitamin E per kg., or 0.10 mg./kg. selenite selenium, or a combination of vitamin E and selenium. Hens fed the basal diet decreased in egg production during the third month and for the remainder of the experiment, a decrease which was mostly corrected by vitamin E, and completely corrected by selenium. Fertility and hatchability of eggs were also low on the basal diet, and were also partly corrected by vitamin E, and completely corrected by selenium. The selenium content of lyophilized egg white and yolk is reported along with the selenium content of several tissues. Gross deficiency signs of the laying hen are also described.

A chronic mycotoxicosis in chicks given toxins from Phomopsis sp. was studied. At the onset of this mycotoxicosis, fatty livers and biliary and Kupffer cell endothelial hyperplasia were present in livers of chicks dosed with culture filtrate. Retardation of growth rates and heavier liver weights were seen in Phomopsis sp. culture filtrate-treated chicks throughout the 6-week trial. Liver glucose-6-P dehydrogenase was significantly higher in culture filtrate-treated chicks than control chicks after 28 days. The plasma albumin levels were estimated from scanned disc-gel electrophoresis patterns. Decreasing levels of plasma albumin were seen in culture filtrate-treated chicks throughout the trial up to 35 days of age. A comparison of lupinosis with mycotoxicosis caused by Phomopsis sp. toxin was made.

The origin of plasma glutathione peroxidase is unclear. Evidence suggests that it is of hepatic origin, but the data are inconclusive. An increase in glutathione peroxidase activity of liver was observed in chicks 4 hr following oral dosage with 20 μg selenium. Activity in plasma was somewhat variable, but tended to remain low following selenium dosage and during the early rise in liver activity. However, 16 hr following dosage, plasma specific activity increased 280%, while that of liver increased 180%. The greatest absolute increase in activity 16 hr after dosage occurred in plasma. Glutathione peroxidase activity changes in plasma did not appear to be closely related to the activity of this enzyme in red blood cells, pancreas, kidney, spleen, or gonad. Ultrafiltration studies failed to demonstrate the presence of a low molecular weight inhibitor in liver or an activator in plasma that might alter enzyme activity.

were subjected to a decrease in hours ofclear, red, blue and green photoperiods. The decrease in photoperiod length of clear and red light inhibited testis development and spermatogenesis. The decrease in photoperiod length in blue and green light failed to show the inhibitory effect. Pituitary gonadotrophin activity indicated that both production and release ofgonadotrophins were inhibited by decreased hours of clear and red light.

A PREVIOUS study to determine why egg weight was less when Japanese quail were fed purified diets than when fed a practical diet showed that adding fiber, amino acids, more protein, a higher level of essential fatty acids and more potassium and phosphorus to the purified diet failed to significantly increase egg weight (Latshaw and Jensen, 1970). Adding the ash of the practical diet (minus vitamin and mineral supplement) to the purified diet also did not increase egg weight, thus indicating that the smaller egg size was not the result of a deficiency of an inorganic nutrient. This study was conducted in an attempt to find an organic component that would increase egg weight when added to a purified diet. EXPERIMENT 1 Procedure. The quail used in this experiment were raised and housed as previously described (Latshaw and Jensen, 1970), with nine females and two males per pen. When egg…

NUMEROUS experiments with laying hens conducted at this laboratory over the past several years have demonstrated that purified diets did not support reproductive performance equal to that obtained with practical diets. Both types of diets were formulated to contain adequate quantities of all known essential nutrients. Menge (1967) observed that rate of egg production, egg weight and hatchability of fertile eggs were significantly lower for hens fed a casein-gelatin-glucose diet compared with a corn-soybean diet. Substitution of isolated soy protein for casein and gelatin in the purified diet improved egg weight and hatchability but not rate of egg production. Young (1969) also noted that hens fed purified diets laid smaller eggs than hens fed a practical diet. The Japanese quail (Coturnix coturnix japonica) was selected to further investigate this problem. Wilson et al. (1961) described characteristics which make the Japanese quail a useful animal for research. Quail also eat less…

Soybeans inoculated with Phomopis sp. were incubated for weeks and then extracted with methanol and ether, and the culture filtrates were intubated into crops of chicks. Activities of glucose-6-phosphatase and glucose-6-phosphate dehydrogenase in liver were increased, and glycogen stores and plasma glucose concentrations were reduced. Histologically, severe hepatocytic necrosis was found in chicks treated with the toxic culture filtrate. Significant clinical signs were loss of body weight and reduced feed consumption. The metabolic changes responsible for the findings are discussed.

Two experiments were conducted to determine the lysine requirement of laying hens. Corn was used as the cereal grain, and cottonseed meal, peanut meal, and corn gluten meal supplied supplemental protein. In Experiment 1 a daily lysine intake of 607 mg. per hen per day was adequate for maximum egg production and egg weight. In Experiment 2 basal diets were calculated to contain 2880 M.E. kcal/kg. or 3110 M.E. kcal/kg. The lysine requirement for the lower energy diet was 657 mg. per hen per day and for the higher energy diet was 636 mg. per hen per day. A lysine requirement of 650 mg. per hen per day is recommended.

The possibility of producing toxic effects in day-old chicks with mycotoxins from Phomopsis sp. or Diaporthe phaseolorum var. sojae isolates was studied. Evidence was found that Phomopsis sp., but not Diaporthe, produces hepatic necrosis with high mortality in chicks. Enzymatically, the hepatotoxin produced by Phomopsis sp. caused an increase in the level of liver glucose-6-P dehydrogenase. Mycotoxicosis caused by Phomopsis sp. was compared with lupinosis.

Practical diets containing various selenium levels, with and without selenite supplementation, were fed to hens. Eggs were then collected over a 14-day period to determine how quickly changes in dietary selenium affected egg white and yolk selenium. Changes in egg white selenium content were rapid and essentially completed seven days after changing the selenium content of a practical diet. Changes in egg yolk were not yet completed by 14 days. When selenium from practical feedstuffs was fed, the selenium content of dried egg white was about equal to or greater than the selenium content of dried egg yolk. When selenite was fed, the selenium content of dried yolk was higher. Feeding selenomethionine resulted in more selenium in egg white than in egg yolk. Feeding selenocystine resulted in more selenium in egg yolk than egg white, a pattern similar to that from feeding selenite. The data suggest that selenocystine is not incorporated into protein but is metabolized to an inorganic selenium compound.

Three experiments were conducted with day-old broiler chicks to determine the effects of dietary choline, biotin, and manganese on cartilage hexosamine and hydroxyproline content. The incidence of leg weakness was 75% or higher on all basal diets. The levels of supplementation found to minimize leg weakness were 1540 mg choline chloride/kg diet, .2 mg biotin/kg diet, and 100 mg manganese/kg diet. The levels required to maintain normal epiphyseal cartilage hexosamine content were 385 mg of choline chloride, .05 mg of biotin, and 25 mg of manganese/kg of diet. Substantially higher levels of nutrients were needed to reduce the incidence of leg weakness. Only with manganese supplementation was the incidence of leg weakness significantly reduced at the level of supplementation required for normal hexosamine content. Hydroxyproline content was not affected by varying the levels of supplemental choline, biotin, or manganese.

Experiments were conducted to determine the relative effectiveness of selenium (Se) from sodium selenite, selenomethionine, and selenocystine for promoting weight gain and preventing exudative diathesis. The chicks used were hatched from eggs low in Se. They were fed a basal diet made up mostly of corn (low in Se) and torula yeast or the basal diet supplemented with various levels of Se from sodium selenite, selenomethionine, or selenocystine. At 10 μg. of added Se per kg. of diet, sodium selenite and selenocystine were about equal in promoting weight gain and preventing exudative diathesis. Selenomethionine was less effective. Tissues from chicks fed the various Se sources providing 60 μg. Se per kg. of diet for four weeks were analyzed for Se. The content of tissues from chicks fed sodium selenite or selenocystine was similar. Chicks fed selenomethionine had a higher concentration of Se in the pancreas and breast muscle than chicks fed the other two Se sources, but a lower concentration in the kidney, liver, and heart. The level of Se in the kidney, liver, or heart which a Se source produces seems to be more important for preventing exudative diathesis than that which is found in the pancreas or muscle.