Effects of ambient temperature, arginine-to-lysine ratio, and electrolyte balance on performance, carcass, and blood parameters in commercial male turkeys

Growth Rate and Bone Hydroxyproline Concentration in Turkeys Fed with a Silage-Composed Diet Modified with Different Diet Cation-Anion Differences (DCADs)

Simple Summary

In this study, we point to the possibility of using dietary cation–anion difference manipulation to improve growth rates and bone condition, especially in the last phase of poultry turkey husbandry, when birds have many bone abnormalities.

Abstract

Our goal was to determine the responses of body weight (BW) and bone hydroxyproline (Hyp) concentration in turkeys fed a corn silage (CS) diet with different values of dietary cation–anion differences (DCADs). The turkeys (n = 90) were divided into five groups and fed as follows: group A (control)—standard diet (SD) (60%) plus CS (40%); group B—SD (60%), CS (40%) plus 240 g of CaCl₂ per 100 kg of diet; group C—SD (60%), CS (40%) plus 480 g of CaCl₂ per 100 kg of diet; group D—SD (60%), CS (40%) plus 240 g of NaHCO₃ per 100 kg of diet; group E—SD (60%), CS (40%) plus 480 g NaHCO₃ per 100 kg of diet. The addition of a lesser amount of CaCl₂ lowered the DCAD, which ranged between 52.5 ± 4.19 and 91.14 ± 3.14 mEq/kg DM. An increased content of CaCl₂ led to high negative values of DCAD. NaHCO₃ supplemented in both doses resulted in a significant elevation of DCAD. Compared to each experimental group, feeding birds with a diet supplemented only with CS resulted in a lower BW. Addition of CaCl₂ or NaHCO₃ to the diet improved BW, but only CaCl₂ addition enhanced the bone Hyp amount. In conclusion, we suggest that an anionic diet with low DCAD can prevent bone abnormalities in large turkeys, especially in the final course of production.

Effects of L-arginine and L-citrulline supplementation in reduced protein diets for broilers under normal and cyclic warm temperature

Heat stress causes significant economic losses in the broiler industry. Dietary supplementation of arginine (Arg) and citrulline (Cit) might increase the performance of broilers raised under warm temperature due to vasodilation effects. This study investigated the effects of L-Arg or L-Cit supplementation in broilers fed a reduced protein wheat-based diet deficient in Arg under thermoneutral (NT) and cyclic warm temperature (WT). Ross 308 cockerels (n = 720) were randomly allocated to 4 dietary treatments with 12 replicates of 15 birds per pen from d 7 to 21. The 4 treatments were: normal protein (NP), i.e., 22.3% and 20.9% crude protein in grower and finisher, respectively; reduced protein (RP), i.e., 2.5% lower protein and deficient in Arg; and RP supplemented with 0.28% Arg (RP-Arg) or 0.28% Cit (RP-Cit). A factorial arrangement of treatments was applied during the finisher phase (21 to 35 d). Factors were: diet (4 diets above); and temperature, NT (24 °C) or cyclic WT (33 ± 1 °C for 6 h per day) with 6 replicate pens per treatment. During 7 to 35 d and 21 to 35 d, the birds fed the RP diet had lower body weight gain (BWG) and higher FCR compared to the NP diet (P < 0.01). The addition of Arg or Cit to RP decreased FCR compared to RP (P < 0.01). During 21 to 35 d, the birds exposed to WT had lower feed intake (FI), lower BWG (P < 0.001) but similar FCR (P > 0.05) compared to birds exposed to NT. Diet by temperature interactions were not observed for performance parameters during the period of WT (P > 0.05). On d 35, the RP-fed birds had a lower yield of thigh and drumstick, higher fat pad, lower femur ash, and breaking strength but similar serum uric acid level and higher nitrogen digestibility on d 21 compared to those offered NP (P < 0.05). Supplementation of Arg or Cit to RP resulted in increased femur ash on d 35 (P < 0.05). Thus, feeding the NP diets is necessary to maintain growth performance in broilers regardless of the temperature conditions.

Increased Dietary Inclusion Levels of Lysine Are More Effective than Arginine in Supporting the Functional Status of the Gut in Growing Turkeys

Arginine (Arg) and lysine (Lys) may be important for the overall health of turkeys. The aim of this study was to determine whether low (consistent with the guidelines) and high (10% higher than recommended) levels of dietary Arg and Lys can modulate performance and the functional status of the gut. Female turkeys were allocated to four dietary treatments (two levels of Lys (low or high) and two levels of Arg (low or high)) for a 16 wk feeding period. The treatments did not affect turkey performance determined separately for four feeding phases and for the entire 16 wk experiment (p > 0.05). They had no significant influence on carcass yield, meat characteristics or the associated traits either (p > 0.05). High-Lys diets contributed to a decrease in cecal pH, a significant increase in the concentrations of short-chain fatty acids (SCFA) and a decrease in the concentrations of putrefactive SCFA and ammonia in the cecum. High dietary levels of both amino acids significantly enhanced the activity of cecal microbiota evaluated based on extracellular enzyme activity. These findings indicate that the higher dietary level of Lys was more effective in modulating the physiological status of the gut in turkeys than Arg.

The immune status, oxidative and epigenetic changes in tissues of turkeys fed diets with different ratios of arginine and lysine

In the present experiment, it was assumed that the appropriate dietary ratio of arginine (Arg) to lysine (Lys) can improve the immune status and growth performance of turkeys. The aim of this study was to evaluate the effects of two inclusion rates of Arg relative to Lys in turkey diets with Lys content consistent with National Research Council (NRC) recommendations or 10% higher on the immune status of birds and indicators of protein and DNA damage due to oxidation, nitration or epigenetic changes. Another goal was to determine which dietary Arg:Lys ratio stimulates the immune response of turkeys vaccinated against Ornithobacterium rhinotracheale. The experiment was performed on 576 turkeys randomly assigned to four groups with two levels of Lys (low = NRC recommendation or high = NRC + 10%) and two levels of Arg (95% or 105% Arg relative to the content of dietary Lys). It was found that the Lys content of turkey diets should be 10% higher than that recommended by the NRC and combined with the higher Arg level (105% of Lys). Although the above Arg:Lys ratio did not improve the growth performance of birds, it stimulated their immune system and reduced protein nitration as well as protein and DNA oxidation.

The effect of different dietary ratios of lysine, arginine and methionine on biochemical parameters and hormone secretion in turkeys

We postulated that the use of optimal levels and proportions of Lys, Arg and Met in compound feed allows for optimal exploitation of the growth potential of contemporary slaughter turkey hybrids and reduces metabolic disorders. The aim of the study was to determine the effect of different proportions of Lys, Arg and Met in diets whose Lys content is in accordance with NRC recommendations, that is a low level, on selected parameters of protein, lipid and carbohydrate metabolism and on hormone secretion in turkeys. The lowest Arg content (90% Lys) in the diet resulted in an increase in plasma total cholesterol levels in the turkeys as compared to higher Arg content (100% or 110% of Lys), (2.50 vs. 2.09 vs. 1.83). Plasma HDL and creatinine concentration increased in turkeys fed diets with higher Arg content (100% and 110% Lys) compared to turkeys receiving the diet with the lowest Arg content (90% Lys). Compared to turkeys receiving the lowest and intermediate Arg content (90% and 100% Lys), the diet with the highest content of this AA (110% Lys) resulted in an increase in the plasma T4 level (71.21 vs. 86.60 vs. 128.2). The varied Arg and Met levels relative to Lys did not affect the secretion of neurotransmitters or hormones regulating glucose metabolism. At low levels of Met in the diet, an decrease in Arg relative to Lys from 100% to 90% caused a growth depression of turkeys (10.68 vs. 10.21 kg), which was not noted in the case of the higher Met content. When using the Lys level recommended by NRC in the turkey diet, the optimal Arg level is 100% and Met is 45% compared to Lys.

Effects of different levels of arginine and methionine in a high-lysine diet on the immune status, performance, and carcass traits of turkeys

We postulated that the use of appropriate levels and proportions of arginine (Arg) and methionine (Met) in compound feed with high lysine content (Lys) would make it possible to fully exploit the growth potential of modern fattening turkey crossbreds, without compromising their immune system. The aim of this study was to determine the effect of different ratios of Arg and Met in diets with high Lys content on the performance and immune status of turkeys. The turkeys were assigned to 6 groups with 8 replicates per group and 18 birds per replicate. Six feeding programs, with 3 dietary Arg levels (90, 100, and 110%) and 2 dietary Met levels (30 and 45%) relative to dietary Lys content, were compared. During each of 4 feeding phases (weeks 0–4, 5–8, 9–12, and 13–16), birds were fed ad libitum isocaloric diets containing high level of Lys, approximately 1.83, 1.67, 1.49, and 1.20%, respectively. The dietary treatments had no effect on daily feed intake or body weight at any stage of the study. The protein content of the breast meat was higher in the treatments with the highest Arg level (110%) compared with the lowest Arg level (90%). Similarly, protein content was higher in the treatments with the higher Met level compared with the lower Met level. Higher plasma levels of tumor necrosis factor, interleukin 6 (IL-6), and immunoglobulin Y were found in turkeys fed diets with the lowest Arg content. An increase in Met content resulted in a decrease in plasma content of IL-6. In growing turkeys fed diets high in Lys, an Arg level of 90% relative to Lys can be used without negatively affecting production results and immune system. Regardless of dietary Arg levels, an increase in Met content does not stimulate the immune defense system and shows no effect on growth performance of turkeys in current trial.

Effects of functional oils on the growth, carcass and meat characteristics, and intestinal morphology of commercial turkey toms

Two experiments were conducted to evaluate the effects of functional oils containing cashew nutshell and castor oil on turkey performance and intestinal morphology. In experiment 1, 585 hatchlings were randomly placed in 15 replicate floor pens, (13 poults/pen) with recycled litter and provided feed and water ad libitum. Birds were randomly assigned to 3 dietary treatments from 1 to 12 wk: nonmedicated control, 0.15% functional oils, and 66-ppm monensin. From wk 13 to 20, each initial treatment group was further divided into 3 treatments—control (no additive), 0.15% of functional oils, or 20 ppm of virginiamycin to produce 9 different treatments, 5 replicate pens per treatment. Data on feed weights were collected weekly, and body weight bi-weekly. At termination (20 wk), birds were euthanized, and their meat was processed to determine mass of carcass sections and meat quality, while intestinal samples were collected for histology. In experiment 1, toms fed monensin or functional oils were 10.5 and 4.5% heavier (P < 0.05), respectively, than the controls at 12 wk. Birds fed monensin had a 4% improvement (P < 0.05) in feed conversion as compared to the other treatments. Neither virginiamycin nor the functional oils affected bird performance when fed from 13 to 20 wk. The jejunum villi surface area at 3 wk was most enhanced (P < 0.05) for the poults fed monensin. Supplementation with functional oils significantly reduced leg yield and thiobarbituric-acid reactive substances of white meat after 7 D of storage (P < 0.05). There were no effects on performance or carcass characteristics in experiment 2. While additional confirmatory studies are needed, functional oils in the diet of turkey toms may be a viable alternative to antibiotic growth promotants.

The effect of different dietary ratios of arginine, methionine, and lysine on the performance, carcass traits, and immune status of turkeys

The research hypothesis postulated that the optimal dietary inclusion levels and ratios of lysine (Lys), arginine (Arg), and methionine (Met) can increase the growth potential of hybrid turkeys and limit metabolic disorders that weaken immune function. The experiment was carried out in a full rearing cycle, from 1 to 16 wk of age, in a two-factorial randomized design with 3 levels of Arg and 2 levels of Met (90, 100 and 110% of Arg, and 30 or 45% of Met, relative to the content of dietary Lys), with 6 groups of 8 replicates per group and 18 turkeys per replicate. In the first and second month of rearing, a significant dietary Arg-by-Met interaction was noted for daily feed intake and body weight gain, and a more beneficial effect was exerted by higher Met content and medium Arg content. Throughout the experiment, the higher dietary Met level increased the final body weight (BW) of turkeys (P = 0.001). Different dietary Arg levels had no influence on the growth performance of turkeys, but the lowest level decreased dressing yield (P = 0.001), and the highest level increased the percentage of breast muscles in the final BW of turkeys (P = 0.003). The lowest Arg level (90% of Lys content) undesirably increased the concentration of the proinflammatory cytokine IL-6 (P = 0.028) and decreased globulin concentration (P = 0.001) in the blood plasma of turkeys. The higher dietary Met level (45% of Lys content) increased plasma albumin concentration (P = 0.016). It can be concluded that higher dietary levels of Met (45 vs. 30% of Lys content) and Arg (100 and 110 vs. 90% of Lys content) have a more beneficial effect on the growth performance and immune status of turkeys.

Determination of the optimum arginine : lysine ratio in broiler diets

The study was conducted to determine the optimum dietary concentration of arginine relative to lysine on the basis of the performance, carcass traits and blood characteristics of 1–35-day-old broilers using a randomised complete block design. One-day-old broilers (n = 1200) were allocated to five dietary treatment groups receiving different arginine:lysine (Arg:Lys) ratios, where the proportion of Arg was progressively increased by increments of 10%, and the concentration of lysine was kept constant; the final ratios were 0.85, 0.95, 1.05, 1.16 and 1.26. Each diet treatment was composed of eight replicates (4 males and 4 females), with 30 chickens each replicate. All broilers were fed in three phases, namely starter, grower and finisher, at 1–10, 11–24 and 25–35 days of age respectively. An increase in the Arg:Lys ratio in the diet from 0.85 to 1.26 linearly (P &lt; 0.001) increased bodyweight gain by 7% and improved feed conversion ratio by 6%. Feed intake and mortality were not significantly (P &gt; 0.05) different among the treatments. Increasing the Arg:Lys ratio in the diet linearly (P &lt; 0.0001) and quadratically (P &lt; 0.05) improved the carcass yield and relative chilled carcass weight respectively. The percentages of breast meat and creatinine and insulin-like growth factor-1 concentrations also linearly (P &lt; 0.0001) increased by 5.5%, 23.0% and 18.0% respectively, with an increasing dietary Arg:Lys ratio. The results of the present study indicated that the highest dietary Arg:Lys ratio (1.26) improved bodyweight gain, feed conversion ratio, breast meat, creatinine and insulin-like growth factor-1. However, the optimum dietary Arg:Lys ratio to improve carcass yield and weight gain in the grower phase (Days 11–24 of age) was at 1.05.

Effect of crude protein concentration and dietary electrolyte balance on litter quality, foot pad dermatitis, growth performance and processing yields in two medium heavy turkey hybrids

1. An experiment was conducted to investigate the effect of crude protein (CP) concentration and dietary electrolyte balance (DEB) on growth performance, processing yields, litter quality and foot pad dermatitis (FPD) in male turkeys from two commercial hybrids. Soya bean meal was replaced by vegetable protein sources selected for lower K concentrations to lower DEB in order to improve litter quality and subsequent quality of foot pads. 2. Effects of CP on litter friability and wetness were not consistent during the production period. FPD in turkeys fed on diets with low CP was significantly lower than FPD in turkeys fed on diets with high CP until 84 d. Growth performance was adversely affected at low CP. Processing yields were not affected by CP. 3. Litter was significantly dryer in pens of turkeys fed on diets with low DEB than in pens of turkeys fed on diets with high DEB. FPD in turkeys fed on diets with low DEB was significantly lower than in turkeys fed on diets with high DEB. Growth performance and processing yields were adversely affected at low DEB. 4. FPD in turkey hybrid A was higher than in turkey hybrid B at 28 d of age. Thereafter, no differences in FPD between turkey hybrids were observed. Growth performance and processing yields were not affected by turkey hybrid. 5. Overall, a significant interaction effect of CP × DEB was observed for FCR: in turkeys fed on the high DEB treatment, FCR of turkeys fed on the high CP diets was lower than FCR of turkeys fed on the low CP (LCP) diets whereas on the low DEB treatment, FCR was not affected by CP treatment. 6. It was concluded that litter quality can be improved and FPD may be decreased in turkeys fed on diets containing lower CP and DEB levels.

Effects of Beak Trimming, Stocking Density and Sex on Carcass Yield, Carcass Components, Plasma Glucose and Triglyceride Levels in Large White Turkeys

This study was conducted to determine the effects of beak trimming, stocking density (D) and sex (S) on live weight (LW), carcass yield and its component, and plasma glucose (PG) and triglyceride levels in Large White turkeys. To accomplish this aims, totally 288 d old large white turkey chicks (144 in each sex) were used. Beaks of 77 male and female poults were trimmed when 8 d old with an electrical beak trimmer. The birds were fed by commercial turkey rasion. Experiment was designed as 2 × 2 × 2 factorial arrangement with 3 replications in each group. Beak trimming and stocking density did not affect live weight, carcass composition and its components. The higher LW and carcass weight observed in trimmed groups. As expected, male birds are heavier than female, and carcass percentage (CP) would be adverse. However, in this study, CP of male was higher in trimmed, in 0.25 m²/bird. (D) × sex (S) interaction had an effect on both CP and thigh weights (p<0.05). Significantly D × S was observed in LW, CP and PG. The weight of carcass and its some components were higher in male. S × D interaction had an effect on plasma glucose level (p<0.05). Triglyceride level was affected (p<0.05) by sex. Significant relationships were found between percentage of thighs (r=0.447, p<0.01) and percentage of breast (r=0.400, p<0.01). According to this study, it can be said that trimming is useful with density of 0.25 m²/bird in turkey fattening.

Cloacal and surface temperatures of tom turkeys exposed to different rearing temperature regimes during the first 12 weeks of growth

Years of genetic selection have caused an increase in growth rate and market body mass in agricultural poultry species compared to earlier genetic strains, potentially altering their physiological requirements. The objective of this study was to expose Hybrid Converter tom turkeys on a weekly basis to the recommended rearing temperature regime (TCON: control) or 4°C below the recommended standard (TTRT: treatment) to determine their thermal responses. Once per week for 12 weeks, 12 turkeys were individually exposed to either TCON or TTRT for a 2-h period. Surface temperatures of the breast (TBREAST), wing (TWING), drumstick (TDRUM), head (THEAD), and shank (TSHANK) were measured at 20-min intervals using an infrared camera, while a thermal data logger measured the skin surface temperature under the wing (TLOGGER) at 30-s intervals. The cloacal temperature (TCORE) was measured using a medical thermometer at the start and end of the exposure period. Regardless of exposure temperature, the TBREAST (TCON: P<0.001 and TTRT: P<0.001), TWING (TCON: P<0.001 and TTRT: P<0.001), and TDRUM (TCON: P<0.001 and TTRT: P<0.001) decreased from weeks 4 to 6 and remained constant from weeks 1 to 3 and 8 to 12. THEAD was elevated in week 2 (TCON: P<0.001) or week 3 (TTRT: P<0.001), TSHANK increased slightly during week 3 for both TCON (P<0.001) and TTRT (P<0.001), and TLOGGER (TCON: P<0.001 and TTRT: P=0.001) and TCORE (TCON: P<0.001 and TTRT: P<0.001) were lower during the first week. Thereafter, THEAD, TSHANK, TLOGGER, and TCORE remained constant. Exposure to TTRT resulted in lower TBREAST, TWING, and TDRUM compared to TCON. Generally, THEAD, TSHANK, TLOGGER, and TCORE were not affected by the different exposure temperatures. The data demonstrated that the degree of thermal response expressed is dependent on the location of measurement, age, and exposure temperature.

Effect of phytase supplementation to diets varying in chloride level on performance, litter moisture, foot pad score, and gait score of growing turkeys

Phytase was examined as a means to improve turkey performance in diets with high Cl by modifying dietary electrolyte balance. Nicholas turkey toms (10 poults/pen; 10 replicates per pen) were fed corn-soy-distillers dried grains with solubles-canola meal-based diets (DDGS/CM) with varying Cl (0.2, 0.3, 0.4, or 0.5%) and phytase (0 or 500 phytase units/kg of diet), making 8 treatments (4 × 2 factorial). A ninth treatment was a corn-soy based diet (CS) with 0.3% Cl and without phytase (positive control). The diets were formulated to contain similar AMEn and digestible amino acid levels for each of 5 feeding periods (2 to 5, 5 to 8, 8 to 11, 11 to 14, and 14 to 17 wk of age) and fed in mash form. Turkey BW, ADG, ADFI, and feed conversion ratio (FCR) were determined for each pen along with litter moisture, foot pad, and gait scores. An ANOVA was conducted to determine the effects of Cl, phytase, and their interaction. Turkey BW, ADG, and ADFI decreased in a linear or curvilinear manner with increasing diet Cl (P < 05). At 17 wk of age, litter moisture and foot pad score showed a cubic trend with diet Cl (P < 0.05). Phytase improved FCR during 8 to 11 wk and increased litter moisture at 11 wk of age (P < 0.003). Phytase modified the FCR response to Cl during 2 to 5 and 14 to 17 wk of age at the 2 lowest levels of dietary Cl (P < 0.05). Turkeys fed CS had better BW and FCR through 17 wk of age compared with those receiving DDGS/CM at 0.3% Cl. Based on BW, minimum dietary electrolyte balance based on Na, K, and Cl was found to be 247, 217, 200, and 171 mEq/kg during 5 to 8, 8 to 11, 11 to 14, and 14 to 17 wk of age, respectively. The present findings emphasized the importance of considering Cl, phytase, and associated dietary electrolyte balance in turkey diets containing high levels of alternative byproducts.

Dietary self-selection by broilers at normal and high temperature changes feed intake behavior, nutrient intake, and performance

Self-selection assumes that at high ambient temperature, birds are able to select a diet from different sources to minimize the heat load associated with the ingested nutrient metabolism. The objective was to test the hypothesis that young chickens are able to compose an adequate ration by adjusting dietary nutrient intake from 3 different diets that vary in energy and in protein contents from a cafeteria system at high temperature (HT; 31-32°C) and at normal temperature (NT; 31-21°C). Night temperature was set at 25°C at HT and at 18°C at NT and 12 h dark:12 h light. Control birds were fed a standard control diet (CP: 215 g/kg; ME: 2,895 kcal/kg) for broiler chickens. The choice-fed birds could choose between the control diet, a high-protein diet (CP: 299 g/kg; ME: 2,780 kcal/kg), and a high-energy diet (CP: 150.7 g/kg; ME: 3,241 kcal/kg). The diets had similar pellet size and color. Birds had access to each diet in a separate feeding trough from 1 to 42 d of age. Results showed that broilers spent 3.3% more time eating at NT than at HT and showed 42% more panting behavior at HT than at NT. High temperature decreased feed intake, protein intake, energy intake, and BW gain. Choice-fed birds had similar feed intake and BW gain, 14% lower protein intake, and 6.4% higher energy intake than control-fed birds. Body temperature and heterophil/lymphocyte ratio were higher at HT than at NT. Water intake was 8% higher in control-fed birds than in choice-fed birds but similar at both temperature regimens. It can be concluded that broilers can compose a diet by selecting less protein but higher energy density from different diets compared with the control. Choice-fed birds had similar feed efficiency as control-fed birds at HT, indicating similar body composition for both groups. Extra energy intake of choice-fed birds at HT was used for panting activity.

Electrolyte diets, stress, and acid-base balance in broiler chickens

We compared the acid-base balance in broiler chickens provided diets containing 2 dietary electrolyte balances (DEB), and administered with either adrenocorticotropic hormone (ACTH) or saline solution. Diets were moderate (174 mEq/kg) or high (241 mEq/kg) DEB formulated by altering Na-K-Cl based on actual analysis. The experiment was designed as a split plot, with the main unit consisting of 4 treatments and the factorial treatment structure arranged in a completely randomized design. Osmotic pumps delivered 8 IU of ACTH in saline/kg of BW per d for 7 d, or the same saline volume as used in ACTH at 1 microL/h for 7 d was implanted on d 35. Venous blood samples were collected on d 35 before the pumps were implanted and on d 42 and 49. Birds fed the high DEB diet exhibited significantly higher Na(+) and Ca(2+) levels than birds provided the moderate DEB diet on d 35. Infusion of ACTH significantly increased (P < or = 0.05) hematocrit, hemoglobin, partial pressure of CO(2) (pCO(2)), corticosterone, osmolality, and HCO(3)(-) and reduced pH, BW, partial pressure of O(2) (pO(2)), and plasma concentrations of Na(+) and Cl(-) in both diets compared with the control group on d 42. Similarly, the ACTH treatment significantly increased hematocrit, hemoglobin, Ca(2+), corticosterone, and osmolality and reduced (P < or = 0.05) pO(2), glucose, and BW on d 49. The diet formulated for high DEB partially lowered pCO(2) on d 42. Significant DEB x ACTH interactions were observed for pCO(2) and pO(2) on d 49. However, there was a reduction in pO(2) along with a concomitant increase in erythropoiesis under the ACTH treatment for both diets, compared with the saline control, because of the increased need for O(2) to support gluconeogenic energy production. This adaptive response provided greater numbers of erythrocytes and thus a higher amount of circulating hemoglobin to deliver O(2) for metabolism. The diet formulated for high DEB partially attenuated the adaptive stress condition in broiler chickens.

Dietary arginine silicate inositol complex during the late laying period of quail at different environmental temperatures

Arginine silicate inositol complex (ASIdagger; arginine 49.5%, silicon 8.2%, inositol 25%) is a novel material which is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health. Poor eggshell quality has been a major economic concern to commercial egg producers. Poor egg quality, skeletal abnormalities and architectural deterioration of bone tissue are common problems under hot conditions and in older birds. The effects of ASI supplementation on egg production, egg quality, levels of osteocalcin (OC) and bone mineral content were investigated in heat-stressed Japanese quail during the later part of the laying period. The birds were randomly assigned to six treatment groups consisting of six replicates of five birds each in a 2 x 3 factorial arrangement of treatments (temperatures, ASI levels). The birds were kept in wire cages in a temperature-controlled room at either 22 degrees C (TN) or 34 degrees C (HS) for 8 h/d and fed either a basal (control) diet or the basal diet supplemented with either 500 or 1000 g of ASI/kg. Heat exposure reduced egg production, egg quality and bone mineralisation when the basal diet was fed. ASI supplementation had no effect on feed intake or egg production under TN or HS conditions. However, ASI supplementation increased egg weight, shell thickness, shell weight and Haugh unit in both TN and HS groups during the late laying period. Bone mineral density (BMD) was significantly improved by ASI supplementation in both TN and HS groups. Serum osteocalcin (OC) concentrations and alkaline phosphatase (ALP) activity increased linearly with dietary ASI supplementation during the late laying period. The amount of calcium and phosphorus in the excreta decreased, while ash, mineral content, calcium and phosphorus concentrations in tibia increased in ASI-supplemented quail in both TN and HS groups during the late laying period. ASI supplementation significantly improved egg quality and bone mineralisation in quail during the late laying period and did not affect feed consumption or egg production.

Dietary arginine silicate inositol complex improves bone mineralization in quail

Skeletal abnormalities, low bone mass, bone deformities, and bone fractures increase the risk of osteoporosis and osteoarthritis, which are of concern from both a public standpoint and a cost-of-care burden standpoint. Arginine silicate inositol complex (ASI; Arg = 49.47%, silicone = 8.2%, inositol = 25%) is a novel, bioavailable source of Si and Arg and one that offers potential benefits for vascular and bone health. Skeletal abnormalities and architectural deterioration of bone tissue are common under hot climate conditions in the poultry industry. In this study, we evaluated the effects of ASI supplementation on performance and bone mineral density (BMD) in Japanese quail (Coturnix coturnix japonica) exposed to the high ambient temperature of 34 degrees C. The birds (n = 180; 10 d old) were randomly assigned to 6 treatment groups consisting of 10 replicates of 3 birds. Birds were kept in wire cages in a temperature-controlled room at either 22 degrees C (thermoneutral; TN) or 34 degrees C (heat stress; HS) for 8 h/d (0900 to 1700 h until the end of study) and were fed a basal (control) diet or the basal diet supplemented with either 500 or 1,000 mg of ASI/kg of diet. Heat exposure decreased performance and bone mineralization when the basal diet was fed (P = 0.001). The ASI supplement had no effect on feed intake, BW, feed efficiency, and carcass traits (P > 0.05) in quails reared under TN or HS conditions. The BMD was significantly improved by ASI supplementation in both TN and HS groups [0.72 (TN) vs. 0.60 (HS); P < or = 0.05]. Serum osteocalcin, dehydroepiandrosterone concentrations, and alkaline phosphatase activity increased, whereas tumor necrosis factor-alpha and Creactive protein concentrations decreased, as dietary ASI supplementation increased in quail reared under HS. This improvement was linear with increased doses of supplement (P = 0.001). In the ASI group, the amount of Ca, P, Mg, and Mn in the excreta decreased (P < or = 0.05), and the concentrations of these minerals in tibia ash increased in quail reared under HS conditions (P < or = 0.05). In conclusion, ASI supplementation to the basal diet significantly improved bone mineralization in quail and did not impact feed consumption, BW gain, or feed efficiency.

Chick responses to dietary arginine and methionine levels at different environmental temperatures

1. Two experiments were conducted with broiler chicks in battery brooders from 1 to 21 d to determine the broiler chicks' responses to arginine (Arg) and methionine (Met) combinations at control (22 to 25 degrees C) and warm (32 to 35 degrees C) temperatures. 2. In Experiment 1, two levels of Arg (15.2 and 25.2 g/kg of the diet) and two levels of Met (3.5 and 5.5 g/kg) of a maize-soy based diet were fed at two temperatures, 22 or 32 degrees C. Results of Experiment 1 were similar to those of Experiment 2, but most treatment differences were not significant. 3. In Experiment 2, chicks were randomly allotted to 9 dietary treatments: 3 levels of Arg (15.2, 25.2 and 35.2 g/kg of the diet) x 3 levels of Met (3.5, 5.5 and 7.5 g/kg of the diet) at 25 or 35 degrees C. At the warmer temperature, chick growth depression from supplemental Arg was not as severe as at the control temperature (significant Arg x temperature interaction); neither were growth increases as large from supplemental Met (significant Met x temperature interaction). 4. Kidney and breast muscles were collected for arginase activity and creatine analysis, respectively. Remaining chicks were fasted for 10 h and re-fed. Excreta from the next 24 h were collected for total creatine and creatinine analysis. There were no effects of either Arg or Met on muscle creatine concentration at either control or warm temperatures. Chicks raised at 25 degrees C excreted more creatine and creatinine than those raised at 35 degrees C. 5. These results confirm that temperature affects responses to dietary Arg and Met and suggest that the higher temperature slowed the Arg metabolism of chicks through the creatine synthesis pathway.

Growth responses to dietary lysine at high and low ambient temperature in male turkeys

Several researchers have postulated that dietary lysine requirements for turkeys are dependent upon ambient temperature. To test and quantify this hypothesis, a factorial experiment was designed with four dietary lysine levels (75, 90, 105, and 120% of NRC lysine recommendations) from 1 d of age onward and two ambient temperatures (15 vs. 30 degrees C) from 4 wk of age onward. Growth performance and carcass yields were measured, and requirements were derived from the fitted exponential response curves at 95% of the maximum possible response above that of the basal diet. In the entire experiment no significant interaction effects between temperature and lysine were observed for feed intake, BW gain, and feed:gain ratio. Exponential curves gave a very good fit (R2 > 0.89) for feed intake, and BW gain responses to dietary lysine concentrations in all age intervals. The dietary lysine requirement was estimated to be 1.67 +/- 0.09%, 1.19 +/- 0.13%, 1.08%, and 0.94 +/- 0.35% from 29 to 56 d, 57 to 84 d, 85 to 114 d, and 115 to 140 d of age, respectively. High temperature decreased all absolute processing yields in kilograms but relative cold carcass yield and relative yields of thighs, drums, and wings were increased by high temperature. Relative breast meat yield and abdominal fat were decreased by high temperature. Turkeys at low temperature responded with more breast meat to high lysine than at high temperature.