ABSTRACT
Over the last few years in the southeastern U. S. some broiler diets have been supplemented with phytase to improve phosphorus digestibility. Enzymes other than phytase, however, have not been added to broiler diets in the southeastern U. S. with any consistent results because nutrient availability of corn and soybean meal based broiler diets is high. Moreover, most commercially available enzyme preparations are designed to allow nutritionists to include relatively high protein grains (i.e., wheat [~11.0%] and barley [~11.0%] versus corn [~8.0%]) in broiler diets. Thus, nutritionists have little experience using enzymes in broiler diets based on corn or sorghum and soybean meal. Two broiler floor pen experiments were conducted to evaluate post-pellet enzyme (KEMZYME C/S for broilers) application to corn and soybean meal diets at different environmental temperatures (warm versus thermoneutral). Growth responses, immunity, and carcass attributes of broilers were measured. The primary active enzyme of in the product tested is alpha-galactosidase, which may improve energy digestibility of soybean meal. Broilers fed diets supplemented with enzyme preparations primarily containing (alpha-galactosidase had improved feed conversion at both environmental temperatures.

J. App. Poultry Res., 2001. 10:186-193

Poultry Science, 2001. 80:358-369

ABSTRACT
The lysine requirement for broiler chicks has been studied extensively. Many factors such as protein quality, experimental conditions, dietary nutrients, and genetic strain affect lysine needs of chicks. Because lysine increases protein synthesis and decreases protein degradation in chicks, its requirement may vary as meat-type broiler genetics are improved. Two experiments were conducted to evaluate lysine needs in the starter period in a slow maturing commercial broiler (Ross × Ross 508) and monitor subsequent effects of lysine level on quantities of salable meat. Lysine deficient diets (0.88% total lysine or 80% of 1994 NRC specifications) were created by blending corn, soybean meal, corn gluten meal, wheat middlings, poultry fat, and crystalline amino acids. Dietary treatments represented graduations of lysine from 80 to 130% of NRC in 10% increments from Days 1 to 18. All broilers received a common diet from Days 19 to 41 and Days 19 to 42 in Experiments 1 and 2, respectively. Quadratic response curves were fitted to growth performance criteria of chicks. Broilers fed lysine levels below NRC specifications as chicks had reduced growth and carcass attributes at Day 41. The lysine level required (95% of the upper asymptote) for chick growth responses was 107% (1.18 % total lysine of diet or 1.07% digestible lysine of diet) to 111% (1.22% total lysine of diet or 1.11% digestible lysine of diet) of NRC (1994).

J. App. Poultry Res., 2001. 10:385-393.

ABSTRACT
A 2 × 3 factorial arrangement of treatments was used in one experiment to evaluate dietary CP (190 and 225 g/kg) and dietary Thr (6.0, 7.0, and 8.0 g/kg) in Ross × Ross 308 male broilers from Days 5 to 15. At Day 5, 336 chicks were randomized across 48 battery pens (seven chicks per replicate and eight replicates per treatment). Essential amino acids, except Thr, were in excess of NRC (1994) specifications and similar between both CP diets. Chicks receiving the 190 g CP/kg diet had increased (P < 0.001) BW gain and feed intake compared with chicks fed the 225 g CP/kg diet. Protein efficiency ratio was improved (P < 0.001) in chicks fed the 190 g CP/kg diet versus chicks fed the 225 g CP/kg diet. Similarly, chicks fed the 190 g/kg CP diet had reduced N excretion (P = 0.043) in comparison with chicks receiving the 225 g CP/kg diet. Increasing dietary Thr from 6.0 to 7.0 g/kg of diet improved (P < 0.001) BW gain and feed intake. Immune organ weights were not affected by dietary treatments. Feed:gain was improved (P = 0.016) in chicks receiving both CP diets as Thr was increased from 6.0 to 7.0 g/kg of diet. However, chicks fed 8.0 g/kg dietary Thr had lower (P = 0.016) feed:gain when fed the 225 g CP/kg diet than chicks fed the 190 g CP/kg diet. Male broiler chicks had improved growth performance measurements when fed 7.0 g dietary Thr/kg of diet. The effect of CP on Thr needs of chicks should be studied further.

An. Feed Sci. Tech., 2001. 57-64

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762; USDA-ARS, South Central Poultry Research Laboratory, Mississippi State, Mississippi 39762; and Department of Biology, Jackson State University, Jackson, Mississippi 39217

ABSTRACT
Broiler chicks were reared in environmental cambers. All birds were started under ideal conditions, i.e., 30.6 C with 35% RH. Beginning at Day 36, half of the chicks were mainlined at 24 C and 35% RH. The other half were subjected to a cyclic temperature-RH regime that approximated a typical August day in central Mississippi (heat treatment). Half of each of the described groups received implants of osmotic pumps that released adrenocorticotropin (ACTH) at 8 IU/kg BW/d for 7 d. The remaining birds received placebo pumps. The main effects of ACTH and heat treatments were similar. Both treatments caused reductions in BW, carcass weight (CW), carcass protein (CP), and muscle calorie (C) content. ACTH, but not heat, reduced carcass moisture (M). Carcass fat and ash, however, were not affected. Most changes were not reversed after 1 wk of recovery. Although visible signs of pale, soft, exudative muscle (PSE) were present, "white" areas of muscle were absent. The decreased meat yield and detrimental changes in meat quality suggest that stress, whether induce hormonally or by exposure to overheating, caused losses that were as severe as those associated with PSE under field conditions.

Key words: stress; pale, soft, exudative; broiler; meat; nutritional value

Poultry Science, 2001. 80:1384-1389

Poultry Science Department, Mississippi State University, Mississippi State, MS 39762; Embrex, Inc., Research Triangle Park, NC 27709

ABSTRACT
Chicken interleukin-2 (cIL-2), which was prepared by sensitizing chicken lymphocytes with concanavalin A, was administered to fertile broiler eggs on Day 18 of embryonation (0.1 mg in 200 mL distilled water). Controls (CON) received distilled water. Hatched chicks were reared to 6 wk. Body weight (BW), as well as abdominal fat pad, liver, bursa of Fabricius, a thymic lobe, spleen, and gonads were excised and expressed relative to BW at 2, 4, and 6 wk of age. Additionally, hematocrit (HCT), hemoglobin (HGB), and plasma protein (PP) levels were determined at the three time intervals. Finally, chicks were sensitized against human gamma globulin (HGG) and challenged at 6 wk by intradermal injections into the wattles. Delayed type hypersensitivity (DTH) to HGG was used as a direct measure of cell-mediated immunity. In ovo cIL-2 increased BW consistently, relative fat pad weights at 2 wk, relative bursa and liver weights at 2 and 6 wk, HBG and relative thymic weight at 2 and 4 wk, and PP at 2 wk. Delayed type hypersensitivity to HGG was not affected by cIL-2. Potential metallic and immunologic mechanisms to explain in ovo cIL-2 effects are discussed.

Key words: Interleukins, Growth, Immunity, Chicken, In ovo, Metabolism

Growth, Development & Aging, 2001. 65:73-81

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39759

ABSTRACT
In a previous report, a method of identification of birds experiencing early symptoms of pulmonary hypertension syndrome (PHS) caused by challenge with Enterococcus faecalis was delineated. This method involved subjective heart scores based on visual observation of a cavity on the external surface of the right ventricular wall (RVW), as well as tonicity and thickness of this wall. Accuracy in identifying birds 48 h postchallenge with E. faecalis was acceptable. However, this method did not attempt to offer other morphological or physiological characteristics for further understanding the etiology of PHS. In the present study, three trials were conducted to establish morphological characteristics of the heart from birds challenged with E. faecalis. In Trials 1 and 2, discrepancies were found in heart length (HL) and thickness of the RVW. In Trial 3, the dry weight of the right ventricle (RV) increased after challenge with E. faecalis, as was the ratio of the mass of the RV to the mass of the total ventricle (TV). Histopathological evidence of hearts and especially lungs of birds challenged with E. faecalis were suggestive of PHS. Results indicated that RV, RV:TV ratio, and histopatholgical evaluation of heart and lungs are complementary to diagnosis of PHS.

Key words: heart, lung, pulmonary hypertension syndrome, broiler, Enterococcus faecalis

Poultry Science, 2002. 81:365-370

Department of Poultry Science, Mississippi State University, Mississippi State, MS 39762, USA

ABSTRACT
1. Morphological development of the heart in fast-growing, meat-type fowl of both sexes was studied.
2. In 4 experiments, fowl were weighed, killed and hearts were dissected at 0, 20, 34, and 48th d of age. Heart weight (HW), length (HL), diameter (HD), and thickness of the right ventricular wall (RVW) and left ventricular wall (LVW) were determined.
3. This is the first description of sexual dimorphic differences in the heart of fowl.
4. Results indicate that males have greater HW, HL, and LVW thickness than females. However, thickness of the RVW during the embryonic period, as indicated by thickness of the RVW at hatching in females, exceeds that of males.

British Poultry Science, 2002. 43:24-27

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762

ABSTRACT
A field strain of Enterococcus faecalis was administered to broiler chicks at doses of 0, 3 × 10⁶, 1.5 × 10⁷, and 2 × 10⁷ bacteria/bird either intra-abdominally or intravenously. In trials 1 to 3, birds were reared communally in a broiler house on pine shaving litter. In trial 4, challenged and control birds were maintained in separate isolation rooms in metal cages with raised wire floors. Challenged birds exhibited a characteristic cavity or depression in the external wall of the right ventricle. A subjective scoring system was devised to quantify challenge effects by assigning each heart a score of 1 to 4. The average number of birds, over all trials and over all dose levels, exhibiting the ventricular cavity was 93%. This value in controls was 5%. The average heart score for challenged birds was 3.1, and that for controls was 0.20. Heart scores of challenged and control chicks were not different in birds reared communally or in separate isolation rooms. Additionally, both routes of administration were equally effective. Results suggest that challenge with E. faecalis caused pulmonary hypertension.

Infection and Immunity, 2001. 69:6318-6322

© [2001], American Society for Microbiology. All Rights Reserved.

Poultry Science Department, Mississippi State University, Mississippi State, MS 39762 USA; USDA South Central Poultry Research Laboratory, Mississippi State, MS 39762 USA

ABSTRACT
Studies were conducted to determine the effects of restricted light and feed on compensatory gain in broilers, processing yields, component distributions and tibia characteristics of broilers. Broiler chicks were placed in 24 pens (60 birds/pen) with sexes separated. Three treatments were utilized: 1) ad libitum feed and 24 h light (L)(control); 2) restricted feed (9h /d) and 24 h L (RF); and 3) restricted feed (9h /d) and 9L:15D (RLF). After 14 d, all broilers were changed to 24 h L and ad libitum feed. At week 6, eleven birds of similar weight per pen were processed with results indicating that male control birds were heaviest. The ready-to-cook (RTC) carcass weights for the control birds were also higher (P > 05). The percent head and neck weights for the RF and RLF birds were higher. Females exhibited a higher percent weight for intestine, abdominal fat pad, liver and lower New York dressed weight with no treatment differences. Control males exhibited the highest RTC as percent of live weights. The control and RF females showed the highest total breast weight as percent of RTC, with the control males exhibiting the highest percentage of breast and thigh meat. No differences were observed among treatments with regard to percentage solid content or breaking strength of the tibiae. Male tibiae exhibited higher breaking strength than females, but were less dense. This study revealed no advantage to the poultry industry or grower in using restricted feeding or a combination of restricted feed and light.

Key words: Feed, light, restriction, yield, tibia, broiler

J. Appl. Anim. Res., 2001. 20:1-14

Poultry Science Department, Mississippi State University, Mississippi State, MS 39762, USA

ABSTRACT
Non-desugarized and dehumanized liquid egg whites were treated with papain prior to drying. The hydrolysis effects of papain on color, solubility, foaming capacity, angel food cake volume and gel strength of egg white solids were evaluated. The color of non-desugarized egg white solid prepared with papain treatment was darker than those of the non-treated controls. This darkening was reduced in the depolarized egg solids. Regardless of dehumanization treatment, the foaming capacity and cake volume of egg white solids increased (P < 0.05), while gel strength decreased (P < 0.05) for the papain treatment. In addition, the more papain used, the better (P < 0.05) the solubility, foaming capacity and cake volume performances.

Journal of Food Engineering, 2002. 51:263-266

© [2002], Elsevier Science Ltd. A11 rights reserved.

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762

ABSTRACT
A model was developed to study stress in chickens. Continuous administration of adrenocorticotropic hormone was employed (ACTH) using physiological mini-osmotic pumps. A validation of controls for this procedure showed that nonhandled (NHCON), sham surgical procedure for pump implantation (SMCON) and surgical implantation of a pump delivering saline (SAL-CON) were all acceptable controls. Continuous delivery of ACTH at 8 IU/kg BW/d for 7 d caused increases in plasma corticosterone (CS), glucose (GLU), cholesterol (CHOL), triglycerides (TRI), high-density lipoprotein (HDL), total protein (TP), and the heterophil/lymphocyte (H/L) ratio. Body weight, as well as relative weights of the major immunobiological organs (i.e., spleen, thymus, and bursa of Fabricius) were decreased. Finally, liver was increased due to lipid and moisture accumulation. This model is the first to show in a single experiment all the increases in major adaptive stress responses of chickens.

Key words: stress, model, broilers, adrenocorticotropic hormone, corticosterone

Poultry Science, 2000. 79:363-369

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762

ABSTRACT
Continuous adrenocorticotropin (ACTH) delivery by mini-osmotic pumps is a reliable method to induce stress in broilers. The present study was conducted to determine the minimum effective dose of ACTH that will evoke physiological stress. Chicks, which had been reared under floor-pen conditions until 5 wk of age received mini-osmotic pumps by surgical implantation. The mini-osmotic pumps delivered 2, 4, 8, or 16 IU of porcine ACTH/kg BW/d for 7 consecutive d. Controls (CON) were untreated chicks. Continuous infusion of ACTH caused dose-related stress responses. Chicks that received 8 or 16 IU showed the greatest responses, whereas those that received 2 or 4 IU were intermediate to the birds dosed with high ACTH and the CON birds. Responses included decreased BW; decreased relative weights of the bursa of Fabricius, thymus, and spleen; and increased relative liver weight. Concomitantly, increased liver lipid and decreased liver moisture were recorded. Plasma concentrations of corticosterone (CS), glucose (GLU), total protein (TP), cholesterol (CHOL), and triglycerides (TRI) and the ratio of heterophils to lymphocytes were increased during ACTH infusion. AC'I'H infusion at 8 IU/kg BW/d for 7 d was determined to be the minimum effective dose that caused physiological stress in broilers.

Key words: stress, adrenocorticotropin, corticosterone, broilers, dosimetry

Poultry Science, 2000. 79:370-376

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 34762

ABSTRACT
The temporal pattern of stress responses following continuous infusion of adrenocorticotropic hormone (ACTH; 8 IU/kg BW/d for 7 d) in broilers was determined in two experiments. Results indicate that the order of responses were elevated plasma corticosterone (CS) by 2 h, elevated plasma glucose (GLU) by 12 h, increased liver weight concomitant with increased hepatic lipid and decreased liver moisture by 18 h, decreased relative weight of the spleen by 24 h, elevated heterophil/lymphocyte (H/L) ratio by 2 d, decreased body weight and relative weights of the bursa of Fabricius and thymus by Day 4, and decreased liver soluble protein content by 12 d.

Key words: stress, broilers, adrenocorticotropic hormone, corticosterone

Poultry Science, 2000. 79:377-382

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762

ABSTRACT
Two similar experiments were conducted to evaluate the effects of stress on growth and feed utilization of broiler chicks. Stress was induced by continuous delivery of adrenocorticotropin (ACTH) at 8 IU/kg BW/d for 7 consecutive d. During the 7-d stress period, ACTH-treated chicks did not exhibit increases in feed intake, but increases in water intake concomitant with an increase in excreta output were recorded. The ACTH caused decreases in digestion of dry matter, proteins, gross energy, and carbohydrates, whereas fat digestibility was unaffected. Digestion of these nutrients was affected more than absorption during the stress period. By 1 wk poststress, all parameters were comparable with those of the control, except for feed intake, which was less than that of CON. The BW of ACTH-treated chicks were lower than CON through 1 wk after cessation of infusion of ACTH. Contrasted to effects during the stress period, after cessation of ACTH-treatment, absorption of all nutrients was reduced, and, during this poststress recovery period, digestion appeared to return to the range of CON values. Results indicate that all physiological parameters with the exceptions of reductions in BW and thymus weight returned to the range of CON values within 1 wk after cessation of ACTH infusion. However, feed intake and absorption of energy dry matter and nitrogenous compounds remained lower than CON at that time. Also, losses in skeletal muscle caused by prolonged gluconeogenesis apparently required extended periods for complete recovery, as evidenced by stressed chicks that did not gain comparably to CON after a 1 wk cessation of ACTH delivery.

Key words: stress, adrenocorticotropin, digestion, metabolism, broilers

Poultry Science, 2000. 79:383-390

Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762

ABSTRACT
Physiological stress was studied in broilers using a new model employing continuous release of adrenocorticotropin (ACTH). A total of 42 adaptive response parameters were evaluated. A treatment response ratio, P-value transformation, and stress score were determined for each parameter. The treatment response ratio was calculated by dividing the maximum response of the ACTH-treated birds for each parameter by the average response of control (CON) birds in all cases in which maximum response of ACTH-treated birds exceeded the average response of CON. This treatment response ratio is designated hereafter as ACTH/CON ratio. In those cases in which average response of CON exceeded maximum response of ACTH-treated birds, the reciprocal equation was employed (i.e., CON/ACTH ratio). Probability value transformations were determined by transforming P-values as follows: NS P-values or those exhibiting significance at values less than probability of 5% were expressed as P < 0.05 = 1, P-values exhibiting significance between 0.05 and 0.02 were expressed as P at 0.05 to 0.02 = 2, and P-values exhibiting significance at probabilities of 1% or less were P < 0.01 = 4. Each stress score was calculated as treatment response ratio times P-value transformation. The 42 response parameters were assigned to one of four adaptive categories, and these were morphologic, endocrine, and blood metabolites; digestion and metabolism; and reticuloendothelial responses. The endocrine and blood metabolites category had the highest average of the four stress response categories, and five of the top ten parameters were found in this category.

Key words: stress, adrenocorticotropin, quantitation, broilers

Poultry Science, 2000. 79:391-395

Department of Poultry Science, Mississippi State University, Mississippi State, MS 39762; South Central Poultry Research Unit, USDA, ARS, Mississippi State, MS 39762; and Ajinomoto Heartland, Inc., Chicago, IL 60631

ABSTRACT
Threonine is typically the third limiting amino acid for broilers. Meeting the threonine minimum in least cost formulation with crystalline L-threonine results in reduced dietary crude protein. This experiment evaluated the effect of dietary threonine from intact protein sources versus that of threonine from intact protein sources and crystalline L-threonine. Ross × Ross 308 broilers (1,440 of each sex) were randomized across 72 floor pens (40 birds/pen). The experimental design consisted of a 2 (sexes) × 6 (dietary threonine) factorial arrangement of treatments (12 treatments and 6 replications/treatment). Threonine treatments consisted of: 1) a control diet with no L-threonine; 2) as 1 plus 136 g/ton of L-threonine; 3) as 1 plus 272 g/ton of L-threonine; 4) as 1 plus 408 g/ton of L-threonine; 5) as 1 plus 544 g/ton of L-threonine; and 6) as 5 with a digestible threonine/lysine ratio of 0.65. All diets were formulated to the same minimum nutrient levels with no crude protein restriction. Dietary treatments were implemented from Days 1 to 20, 21 to 35, and 36 to 48. Growth responses were measured for each period and carcass responses were measured at Day 49. There were no significant threonine × sex interactions. Also, dietary threonine treatment differences did not occur for any parameter measured. Body weight gain, feed intake, and carcass parts weights were improved (P<.05) in male broilers versus female broilers, but female broilers had better (P<.05) feed conversion and livability. Although all treatment diets met adequate minimum levels of essential amino acids, treatment diets containing L-threonine had lower nutrient levels of isoleucine, arginine, valine, and tryptophan. Hence, the marginal increase of these less limiting amino acids in the control diet did not affect growth or carcass attributes. Formulating diets to contain up to 544 g/ton of L-threonine does not affect growth or carcass attributes of commercial broilers.

Key words: Amino Acid, broiler, threonine

J. Appl. Poult. Res., 2002. 11:83-89

Poultry Science Department and Alabama Agricultural Research Station, Auburn University, AL 36849-5416; and Department of Poultry Science, Mississippi State University, Mississippi State, MS 39762 ABSTRACT
This study evaluated nitrogen and energy utilization by male and female broilers that were at 46 and 54 d of age fed diets deficient or adequate in threonine. Birds were reared in floor pens of an open-sided house and were provided diets that met NRC (1994) nutrient recommendations from placement until 6 wk of age. At 42 d, 48 birds (24 per sex) were selected and individually penned in Petersime batteries and were given feeds that were formulated to contain 0.52 or 0.74% total threonine having 18% CP and 3,200 kcal ME/kg. Two 24-h excreta collection periods were conducted on Days 46 and 54 to assess nitrogen and energy recovery. Males receiving adequate threonine had an advantage in retention of nitrogen and recovery of AME_n over males consuming the low threonine diet. Utilization of nitrogen by females was similar at both threonine concentrations, and AME_n corresponded to the concentration recovered by males when threonine was adequate. Inadequate threonine appears to create conditions that reduce recovery of energy by male broilers. (Kc>y woodsy ) 2001 Poultry Science 80:

Key words: amino acid, broiler, energy, nitrogen, threonine

Poultry Science, 2001. 80:926-930

Nutri-Quest, Inc, Chesterfield, Missouri 63017 and Department of Poultry Science and the Interdepartmental Nutrition Program, North Carolina State University, Raleigh, North Carolina 27695

ABSTRACT
A study was conducted to evaluate Thr responses in Large White (British United Turkeys) male turkeys dung three time periods: 0 to 3, 3 to 6, and 6 to 9 wk of age. The Thr-deficient diets, fed in 3-wk intervals, were composed primarily of corn, peanut meal, poultry meal, and soybean meal as intact protein sources and supplemented with amino adds. Graded levels of L-Thr were added to the Thr-deficient diets. Another group of turkeys received a corn-soybean-poultry meal control diet in each time period. Diets were formulated to meet a minimum of 110% of suggested amino acid specifications (NRC, 1994) for all essential amino acids, except Thr. Feed intake, BW gain, and feed:gain responses were measured. Average environmental temperatures for Weeks 1, 2, and 3 were 29, 27, and 24 C, respectively. From 4 to 9 wk of age, average environmental temperatures varied between 24 and 35 C. Turkeys in each time period responded to Thr in a curvilinear manner with responses at the asymptote being equivalent to turkeys fed the corn-soybean meal control diets. Adequate dietary Thr levels for gain and feed:gain for the 0 to 3 wk period were 0.93% (3.21 g Thr/Mcal ME) and 0.97% (3.34 g Thr/Mcal ME) of diet, respectively. From 3 to 6 wk of age, the level of dietary Thr needed to support adequate BW gain and feed:gain was 0.88% of diet (2.81 g Thr/Mcal ME). The level of dietary Thr needed to support adequate BW gain and feed:gain from 6 to 9 wk of age was 0.77% of diet (2.30 g Thr/Mcal ME). These results indicate that the NRC (1994) estimations of Thr needs up to 9 wk of age are more than adequate.

Key words: turkey, threonine, amino add, crude protein

Poultry Science, 1998. 77:1550-1555

Nippon Veterinary and Animal Science University, 1-7-1, Kyonan-cho, Mushashino-shi, Tokyo, Japan, 180-8602; and Poultry Science Department, Mississippi State University, Mississippi State, Mississippi 39762-9665

ABSTRACT
Two experiments were conducted to evaluate the effect of in ovo amino acid (AA) injections in broiler breeder eggs on AA utilization of embryos. All AA used in these experiments were pure crystalline AA in free-base form. Treatments in Experiment 1 comprised 1) control eggs (no injection), 2) 0.5 mL sterile-distilled water injected eggs, and 3) eggs injected with an AA solution suspended in 0.5 mL sterile-distilled water. Injections were administered into the yolk at Day 7 of incubation. At hatch, chicks were killed and bled, and plasma AA concentration was determined. Plasma AA concentration of hatched chicks decreased (P<0.05) when water was injected. In addition, all AA from eggs injected with AA, except Glu and Lys, were decreased (P<0.05) at at hatch as compared to control eggs. However, AA pattern was not affected by in ovo water injection, but the AA ratio to Lys was reduced by in ovo AA injection.
Experiment 2 was conducted to evaluate whole internal egg AA concentrations over incubation time in the presence or absence of in ovo AA administration. Treatments in Experiment 2 comprised 1) control eggs (no injection), and 2) eggs injected with a AA solution at Day 7 of incubation. The AA contents of embryo, yolk, albumen, and allantoic and amnion fluids were analyzed over time during incubation (Days 0, 7, 14, and 19 of incubation). On Day 14 of incubation, there were no differences in AA contents of all tissues between the control group and the group injected with AA on Day 7 of incubation. On Day 19 of incubation, AA contents of embryo, yolk, albumen, and allantoic and amnion fluids were increased (P<0.05) as mediated by in ovo administration of AA Day 7 of incubation. These results suggest that in ovo administration of AA may increase AA concentrations in chicken embryos and other egg contents.

Key words: amino acid, in ovo, egg, plasma amino acid, broiler breeder

Poultry Science, 2001. 80:1430-1436

Nippon Veterinary and Animal Science University, 1-7-1, Kyonan-cho, Musashino-shi, Tokyo, Japan, 180-8602; and Department of Poultry Science, Mississippi State University, Mississippi, MS 39762-9665

ABSTRACT
Three experiments were conducted to evaluate the effect of differences in in ovo amino acid (AA) injection sites in broiler breeder eggs on subsequent hathability and BW of chicks. In Experiment 1, an AA solution was injected into eggs with l3-mm or l9-mm, 27-ga needles. Uninjected eggs served as controls. Hatchability was decreased (P<0.05) in eggs receiving AA injections with the l9-mm needle in comparison to the control and l3-mm-injected groups. However, BW of chicks increased (P<0.05) relative to pre-incubational egg weight by AA injection with the l3-mm needle. In order to evaluate the in ovo location of AA injections from Experiment 1, India ink was injected into eggs in Experiment 2 with a l3-or l9-mm needle. Immediately after injection, the air cell end of the egg was windowed in order to observe effects of injection site. Windowing of eggs was accomplished by removing a piece of the eggshell over the air cell and the underlying membrane at Day 7 of incubation. The amount of injected India ink was higher in the extra-embryonic coelom in eggs treated by both needles. However, the occurrence of India ink in the extra embryonic coelom was higher (P<0.05) in the group injected with AA solution using a 13-mm needle as compared to that after injection using a l9-mm needle. The observation of India ink in the amniotic cavity was higher (P<0.05) in the group injected with AA solution using a l9-mm needle rather than that using a l3-mm needle. In Experiment 3, treatments consisted of control (uninjected eggs) or windowed eggs. Windowed eggs received AA to the chorioallantoic membrane, the yolk, extra-embryonic coelom, or amniotic cavity at Day 7 of incubation. Hatchability was reduced, but chicks hatched when eggs were windowed and when AA were injected into the yolk sac or extra-embryonic coelom. However, chicks did not hatch when AA were administered to the chorioallantoic membrane or into the amniotic cavity. These results suggest that the best AA injection sites in ovo may be the yolk and extra-embryonic coelom.

Key words: amino acid, in ovo, egg, injection site, broiler breeder

Poultry Science, 2001. 80:1425-1429