Limiting amino acids after methionine and lysine with growing turkeys fed low-protein diets.

The effectiveness of Thr and other amino acids (AA) replacing CP in Met- and Lys-adequate diets of Large White male turkeys was studied from 6 wk to market age. Experiment (EXP) 1 examined efficacy of Thr and an AA grouping in corn-soybean (CS) diets containing 82.8 and 77.0% of NRC CP and in corn-soybean-canola-meat (CSCM) diets containing 85.2 and 79.4% of NRC (1984) CP. Experiment 2 compared AA responses in CSCM diets containing 100, 92.5, 85, and 77.5% of NRC (1994) CP. Compared with control CP, 1) 92.5% of NRC CP supported maximum BW, and supplemental Thr or Trp was without effect; 2) 82.8 to 85.2% of NRC CP resulted in reduced BW and breast meat yield (BMY), and supplemental Thr or Trp was ineffective in reversing this reduction, and 3) 77 to 79% of NRC CP resulted in depressed BW and BMY. Supplemental Thr provided a substantial positive BW but no BMY response, whereas a combination of Thr, Ile, Val, Arg, and Trp completely returned BW and partially returned BMY to that of the normal CP control. Turkeys on CS and CSCM assay diet series supported BW responses to CP and AA similarly. We concluded that in low-CP diets containing Met and Lys to requirement, supplemental Thr resulted in improved BW, whereas Thr, Ile, Val, Trp, and Arg returned BW, but not BMY, to normal CP control.

Identification of limiting amino acids in methionine- and lysine-supplemented low-protein diets for turkeys.

Large White male turkeys were fed 100, 85, 70, or 60% of NRC (1994) CP during 7 to 28 d (Experiment (EXP) 1), 8 to 12 wk (EXP 2), and 16 to 20 wk (EXP 3) of age. Diets contained corn, soybean, canola, and meat meals and were supplemented with Met and Lys to requirement. The influence of supplementary amino acids (AA) was studied at each protein level. Turkeys fed 85% CP gained BW similarly to those fed 100% of NRC CP (control) during each age range. Supplemental Thr, Val, and Ile during 7 to 28 d or 8 to 12 wk, or Thr during 16 to 20 wk, did not result in positive BW gain response. For turkeys fed 70% CP, BW gain was depressed compared with the normal-CP control in each period. During 7 to 28 d and 8 to 12 wk of age, the combination of Thr, Ile, Val, Arg, and Trp to 100% of NRC reversed the BW depression; here only Thr, Ile, and Val were essential components of the response. The BW depression during 16 to 20 wk was reversed by the combination of Thr, Ile, Val, and Trp. For turkeys fed 60% of CP, BW gain was severely depressed. The combination of Thr, Ile, Val, Trp, and Arg resulted in nearly complete BW recovery during each age.

Effect of dietary phosphorus, calcium, and phytase on performance of growing turkeys.

Female and male turkeys were fed 110, 73, 52, and 30% of the NRC (1994) nonphytate P (NPP) requirement without and with 500 phytase units (FTU)/kg during 4 to 14 or 16 wk of age, respectively. At 110% P (control; also 110% of NRC Ca), phytase was without effect. At 73% of NPP (100% Ca), without phytase, performance was similar to the control; with phytase, performance was equivalent, and in some stages, superior to the control. At 52% of NPP (90% Ca), performance was inferior without phytase and was variably similar or poorer than the control with phytase. At 30% NPP without phytase, poults gained poorly and showed a high incidence of leg disorder at 8 wk when they were removed from experiment; poults gained better with 80% NRC Ca compared with 110%. At 30% NPP with phytase, turkeys performed remarkably well, although suboptimally, at 80 or 110% NRC Ca. Phytase at 400, 300, and 200 FTU/kg with increasing age periods performed as well as 500 FTU/kg with 73% of NRC NPP (100% Ca) and 52% NRC NPP (90% Ca). These lower phytase levels were not as sufficient as 500 FTU/kg with 30% of NRC NPP; this inadequacy was more severe with higher dietary calcium. Phytase was effective in reducing dietary P requirements of growing turkeys when the NPP levels were below NRC (1994) requirements.

Utilisation of U-14C-lysine by young turkeys.

1. U-14C-lysine was administered by tube into the crop to turkey poults fed on assay diets (maize + sesame + maize gluten meal) containing varying concentrations of lysine, and partition of the label into body components, carbon dioxide, and excreta was measured. 2. Deposition of 14C label into breast and heart muscles responded positively to dietary lysine concentration. There was no apparent relationship between dietary lysine intake and deposition of label into carbon dioxide or excreta. 3. Efficiency of lysine retention, above maintenance, was estimated to be 0.523 +/- 0.034. 4. Turkeys exhibited variable metabolic efficiency in the use of lysine as indicated by loss of U-14C-lysine label to expired carbon dioxide and to excreta by individual turkeys.

Effects of dietary protein, methionine and lysine on urinary amino acid excretion in turkeys.

1. Two experiments were conducted to determine the influence of dietary protein and amino acids on urinary excretion of amino acids and nitrogen in colostomised turkey hens. 2. Normal and colostomised turkeys 8 weeks of age were fed on control and high protein diets. Body weight gains of both types of birds were similar. Diet did not affect the amino acids in the urine significantly, but urinary nitrogen was higher with the high protein diet. 3. Normal and colostomised turkeys 10 weeks of age were fed a diet with either supplemental DL-methionine or L-lysine hydrochloride (each 20 g/kg diet). DL-methionine depressed gain and resulted in considerable excretion of methionine in urine. Lysine had little effect on weight gain or urinary lysine.

An improved colostomy technique in turkeys.

1. A modified method for colostomy of turkeys was developed which allowed normal and consistent gains for 4 to 8 weeks. 2. Female Nicholas turkeys, 5 to 7 weeks of age and weighing 1.2 to 2.2 kg body weight, were subjects. Major adjustments in the technique included: transfixing of the peritoneum with 4 stay sutures prior to opening, suturing the peritoneum to the seromuscular coat of the colon, eversion of the end of the colon and joining of adjacent skin to the rim of the colon. 3. Urine was collected in a plastic bag attached around the vent with a urine collection fitting. Faeces passing through the colostomy were collected on a tray below the cage.

Replacing protein in corn-soybean turkey diets with methionine and lysine.

The extent to which dietary protein can be minimized by using Met and Lys supplements for market turkeys has been investigated in three experiments involving 2,750 birds. Large White (Nicholas) male turkey poults were fed corn-soybean meal diets of varying protein level to supply Lys from 80 to 120 of NRC (1984) from day-old to 18 wk of age. Performance with diets of 90% NRC Lys was equal to that with diets of higher Lys, provided that SAA were at 100% of NRC. Up to .2% Lys.HCl could be substituted into the 100 or 90% of NRC diets with no depression in performance, suggesting that the other essential amino acids were present in adequate amounts. When turkeys were fed diets of 85% of NRC (1984) Lys, maximum growth and breast meat yield were obtained with supplemental SAA at 100% during 0 to 18 wk of age and Lys at 100% during 12 to 18 wk of age. The requirements for other amino acids were supplied by diets formulated to provide 85% of the Lys requirement from protein. These values were for turkeys subjected to 18 C during final growout; they were not adequate in warmer temperatures.

Effect of cycling temperature on growth, energy metabolism and nutrient retention of individual male turkeys.

1. Each week, from 12 to 20 weeks of age, male turkeys of a heavy strain were subjected to cool (C; 16 degrees C), hot (H; 29 degrees C), and cycling temperatures, and fed on a standard diet ad libitum for 4 d. Lighting was intermittent, 3 h on, 3 h off. Food was given when lights were on. Those given cycling temperatures (3 h C; 3 h H) were given food and light during the cool (eat-when-cool, EC) or hot (EH) periods. 2. Birds in all treatments gained similar amounts of weight from 12-14 weeks of age. Thereafter, birds in C maintained gains, the body weight gains of birds in EC and EH declined moderately and birds in H lost weight. 3. Birds in C produced more metabolic heat. Those in H showed increased heat production as they became older. 4. Protein retention was greater in turkeys in C, EC and EH. It was lower in H, becoming negative between 18-20 weeks of age. Birds in H suffered body fat losses which increased with age. 5. Birds in EH and EC gained similar amounts of body weight. Birds in EH exhibited lower heat production and greater energy retention than those in EC. 6. Body temperatures were higher in H than in the other environments.

Dietary biotin and turkey breeder performance.

The effect of biotin supplementation on turkey breeder hen performance was examined in two experiments. A corn-soybean meal-based breeder diet was supplemented with biotin to provide a low (.178 mg/kg) and high (.75 mg/kg) level of dietary biotin. The diets were fed to female-line hens (Nicholas strain) starting at time of light stimulation (31 and 30 wk of age for Experiments 1 and 2, respectively) for 27 wk. Each diet was fed to four replicate pens of 25 hens each. In Experiment 1, egg production and hatchability of fertile eggs from hens fed the high level of biotin was significantly greater (P < .05) during 50 to 54 wk of age. Egg production and hatchability were improved by 22 and 10%, respectively, from 50 to 54 wk of age. In Experiment 2, reproductive performance was unaffected by biotin level during 33 to 57 wk of age. The higher level of dietary biotin seemed beneficial in supporting later reproductive performance in one of two experiments.

Influence of virginiamycin on growth and efficiency of large white turkeys.

Efficacy of virginiamycin (22 mg/kg) in combination with no drug, amprolium, carbarsone, halofuginone, or monensin, was studied. Male and female turkeys were raised to market age in five experiments conducted from 1983 to 1987. Body weights and feed:gain responses to virginiamycin for males and females were positive and significant (P less than .05). Virginiamycin resulted in mean 5.2 and 6.3% body weight responses and 3.3 and 2.2% feed:gain responses for males at 19 or 20 wk of age and for females at 16 or 17 wk of age, respectively. Mortality rates were low in all studies, and were not influenced by virginiamycin. In a processing study, virginiamycin in combination with halofuginone did not affect shrinkage, yield, or market grade. Feed was utilized by males and females 3.9 and 3.0%, respectively, more efficiently than expected with dietary virginiamycin, compared with results predicted by a simulation modeling technique. Profitability was considerably greater with dietary virginiamycin using actual data than with simulated feed consumption data.

Effect of diet and population density on male turkeys under various environmental conditions. 1. Turkey growth and health performance.

The performance of 1,312 male market turkeys (Large White, Nicholas strain) from 0 to 20 wk of age fed diets varying in feed form and energy level was measured under two stocking densities (.21 or .46 m2 per bird) and four lighting and temperature programs. The four diets were 1) corn and soybean meal with 1% supplemental fat, mash (CSM); 2) as 1, pelleted (CSP); 3) as Diet 1 but with 1, 2, 4, 6, and 8% supplemental fat during 0 to 4, 4 to 8, 8 to 12, 12 to 16, and 16 to 20 wk of age, respectively (CSF); and 4) as Diet 1 but with barely included at 0, 20, 35, 50, and 65% during the respective 4-wk age periods (CSB). The four light and temperature programs were 1) Environment A with intermittent light [4 [2 h light (L):4 h dark (D)]] in combination with cycling temperature at 7 and 21 C during light and dark photoperiod, respectively; Environment B with intermittent light, 21 C; Environment C with continuous light (18L:6D) and cycling temperature of 7 to 21 C; and Environment D with intermittent light, 7 C. Lighting and temperature programs started at 1 and 4 wk of age, respectively. Body weights at 20 wk of age decreased (P less than .05) with increasing temperature (13.86 versus 12.26 kg for Environments D and B, respectively) with cycling temperature intermediate (13.51 kg for Environment A). Intermittent light (P less than .05) improved BW and feed conversion by 3.4 and 2.0%, respectively, compared with continuous light. Rearing males at .21 m2 per bird versus .46 m2 per bird decreased weight (P less than .05) by 5.5%. Twenty-week BW of males fed the CSP (13.52 kg) and CSF (13.58 kg) diets were greater (P less than .05) than those fed CSM (12.90 kg) and CSB (12.69 kg) diets. Significant (P less than .05) interactions between diet, environment, and density were not detected for most performance characteristics. Environmental measurements indicated higher dust and ammonia levels in the warm environment (B). Isolates of aspergillus and incidence of airsacculitis at time of processing were greatest in Environment B.

Effect of diet and population density on male turkeys under various environmental conditions. 2. Body composition and meat yield.

Large White Nicholas male turkeys were reared at two stocking densities (.21 or .46 m2 per bird) and fed one of four diets: 1) control corn and soybean (mash) with 1% fat (CSM); 2) as Diet 1, pelleted (CSP); 3) as Diet 1 with supplemental fat increasing from 1 through 8% with age (CSF); and 4) as Diet 1 with barley at 0, 20, 35, 50, and 65% during successive 4-wk periods (CSB). The turkeys were reared in four environments: (A) intermittent light schedule [4(2 h light (L):4 h dark D))] with temperature at 7 or 21 C during light and dark photoperiod, respectively; (B) and (D) with intermittent light (2L:4D) with a constant 21 and 7 C temperatures, respectively; (C) continuous light cycle (18L:6D) with temperatures as in Environment A. At 20 wk of age, two turkeys per replicate pen, were killed for determination of body composition and meat yield. Compared with turkeys fed CSM diet, those on CSF and CSP diet had increased percentage carcass fat. Meat yield per bird and percentage carcass fat were greater for turkeys reared at .46 m2 per bird compared with rearing at .21 m2 per bird. Pelleting and fat supplementation resulted in significantly increased amounts of breast meat and leg compared with CSM. Breast meat yield (percentage) and amount were greater at 7 C (Environment D) than at 21 C (Environment B) and the cycling regimen (Environment A). Percentage abdominal fat was greatest at 7 C. Interactions of environment and diet were detected for breast meat yield percentage (P less than .023) and weight (P less than .036). Diet type had no effect on percentage breast meat or weight in Environment C. An increased amount of breast meat was obtained by feeding CSP in Environments A, B, and D, and dietary fat supplementation increased breast meat yield in Environments A and D over CSM treatment.

Nutritional evaluation of blood meal and feather meal for turkeys.

Three samples each of commercial blood meal (BL) and feather meal (FEA) were obtained in Minnesota. True amino acid availability (TAAA) and TMEn contents were determined using Large White male turkeys at 8 wk of age. Average TMEn were 3,458 and 2,976 kcal/kg (DM basis) for BL and FEA, respectively. The TAAA of BL ranged from 86 to 91% for each of 15 amino acids except for isoleucine (74%) and cystine (79%). The TAAA of FEA ranged from 59 to 83%. The three feather meals averaged 72, 72, and 76% in amino acid availability. Two ring-dried blood meals averaged 86 and 82% and one spray dried blood meal averaged 91% in amino acid availability. A positive linear relationship was found between TMEII and TAAA of blood and feather meal samples, suggesting the possibility of approximating the estimation of one from the other in certain ingredients of high protein content.

Lysine requirements of growing turkeys in various temperature environments.

The lysine requirement of Large White male turkeys (Nicholas strain commercial cross) was determined in two experiments at different environmental temperatures for two age periods (8 to 12 and 16 to 20 wk of age). Response curves (segmented and exponential) were obtained by regressing body weight gain (grams/day) on dietary lysine concentration (percentage) or lysine intake (grams/day). Varying levels of dietary lysine were obtained by supplementing a corn-sesame meal diet with L-lysine.HCl. Temperature affected percentage lysine requirement as determined by the segmented (broken line) regression model during 8 to 12 wk of age in Experiment 1 (P less than .05) and in Experiment 2 (P less than .10). The requirements (mean +/- SE) by broken line regression for the 8 to 12-wk age period were: Experiment 1, 1.13 +/- .02 and 1.25 +/- .02% at 6 and 23 C, respectively, and Experiment 2, 1.10 +/- .03, and 1.23 +/- .04% at 7, 20, and 26 C, respectively. For the 16 to 20 wk age period the requirements for Experiment 1 were .75 +/- .02 and .77 +/- .03% at 8 and 24 C, respectively. For Experiment 2, requirements were .74 +/- .03, .72 +/- .02, and .78 +/- .02% at 7, 16, and 24 C, respectively. Percentage requirements by the exponential model showed the same patterns relative to temperature. Multiple regression analysis of gain on lysine intake and temperature indicated that variability in gain was primarily explained by intake (R2 ranged from .82 to .97) with deficient lysine intakes. Temperature environment also affected the gain response to lysine intake, resulting in different response curves at the different environmental temperatures.

Early protein undernutrition and subsequent realimentation in turkeys. 1. Effect of performance and body composition.

Male and female Large White Nicholas turkeys were fed corn and soybean meal diets for 24 and 20 wk, respectively. Control and low protein (75% of control in protein and 66% of control in lysine and methionine) diets were fed during 0 to 6 wk of age. Thereafter, both groups received the control diet. Body composition of turkeys was determined at 0, 2, 4, 6, 8, 12, 16, 20, and 24 (males), and at 0, 2, 4, 6, 8, 11, 14, 17, and 20 (females) wk of age. Compared with controls, undernourished turkeys had depressed body weight gain, lower feed intake, poorer feed efficiency, reduced carcass protein, increased carcass fat, and better efficiency of protein retention at 6 wk of age. During realimentation (after 6 wk of age), undernourished turkeys increased average daily feed consumption to that of controls and showed increased weight gains. By 24 and 20 wk of age, weights of undernourished male and female turkeys were no longer different from the weights of their respective controls. Feed efficiency of undernourished turkeys was better than that of controls during realimentation. Differences in body composition of undernourished and control turkeys were no longer evident after realimentation.

Early protein undernutrition and subsequent realimentation in turkeys. 2. Effect on weights and proportions of organs and tissues.

Male and female Large White Nicholas turkeys were fed corn and soybean meal diets for 24 and 20 wk, respectively. The same series was fed with a low protein modification (75% of control in protein and 66% of control in methionine and lysine per Mcal ME) during 0 to 6 wk of age. For the study of organ and tissue growth, six male turkeys per treatment were sampled at 2, 4, 6, 8, 12, 16, 20, and 24 wk of age. Six females per treatment were also sampled at 2, 4, 6, 8, 11, 14, 17, and 20 wk of age. Weights of eviscerated carcass, breast, thigh, drumstick, wing, back, neck, feathers, liver, heart, pancreas, alimentary tract less gizzard, and gizzard were depressed by early protein undernutrition to 6 wk of age. Compared with values for controls, undernutrition increased proportions of the liver, alimentary tract less gizzard, gizzard, and heart at 6 wk of age; proportions of the back, neck, feathers, and pancreas were not affected, but breast and thigh proportions were reduced. Compensatory growth during realimentation eliminated all differences between undernourished and control turkeys in weight and proportions of organs and tissues by 20 wk of age.

Effects of white lupine in diets of growing turkeys.

In Experiment 1, dehulling white lupine (WL) improved growth and feed efficiency of male Large White turkey poults fed 40% WL during 4 to 21 days of age. In Experiment 2, WL was included proportionally with soybean meal in corn-soy diets of female turkeys from 0 to 17 wk of age. Soybean meal: WL ratios (S:WL) were 1:0 (control), 2:1, 1:1, and 6:1. At 17 wk of age hens on S:WL diets of 2:1 had body weights that were similar to those of birds fed the corn-soy control diets. Growth of hens fed S:WL diets of 6:1 was depressed (P less than .05). Growth depressions were greatest earlier in the study; older birds made compensatory gains. Feed efficiency of hens fed S:WL diets of 1:1 was poorer than that of controls during 0 to 11 wk but better than that of controls after 11 wk of age. Feed efficiency values were similar during 0 to 17 wk for hens fed control and S:WL diets of 2:1 and 1:1. Sensory evaluation of roasted light and dark meat of market birds revealed no taste differences in relation to WL level in the diet.

Protein, methionine, and lysine requirements of growing hen turkeys under various environmental temperatures.

Two experiments were conducted to study the protein and amino acid requirements of growing Large White female turkeys at temperatures of 7, 14, 21, and 28 C. In Experiment 1, five dietary treatment series (A, B, C, D and E) which ranged in protein content from 24.3 to 16.9, 20.4 to 14.2 and 17.8 to 11.9%, were fed during 8 to 11, 11 to 14, and 14 to 17 wk of age, respectively. The D diet series was also supplemented with methionine or lysine or both to equal the levels in the B series forming the D, DM, DL, and DML treatments. In Experiment 2, B and C protein levels were fed between 11 and 14 wk of age. Between 14 and 17 wk of age, the B, C, D, and E protein levels were fed to each group forming a 2 X 4 factorial arrangement. In Experiment 1, during 8 to 11 wk of age, body weight gain decreased when birds were fed diets containing less than 22.5% protein. From 11 to 14 wk of age, at 7 and 14 C, the C diet supported maximum gains but at 21 and 28 C, the B and A diets, respectively, resulted in heavier turkeys. With the D diet, methionine supplementation significantly (P less than .05) improved body weight of birds during 8 to 11 and 11 to 14 wk of age: lysine supplementation had no effect during 8 to 11 wk and inconsistent effects on gain during 11 to 14 and 14 to 17 wk of age. Results from 14 to 17 wk of age show that the protein requirement of female turkeys during this age was overestimated by the National Research Council in 1984.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of halofuginone as a coccidiostat for turkeys.

Large White male turkeys were raised to 20 wk of age on diets with varying kinds and levels of coccidiosis drug protection. Dietary treatments included unmedicated control (UMC), amprolium (AMP, 125 mg/kg), and 3 levels of halofuginone hydrobromide (HAL, during 0 to 4 and 4 to 8 wk of age, in 3.3; 3.1.5; and 1.5,1.5 mg/kg, respectively). Turkeys on these five treatments were exposed to coccidial oocysts at 14 days of age and again at 61 days of age; turkeys in an identical five treatments were not exposed until 61 days of age. At 28 days, nonexposed turkeys gained well and similarly, whereas exposed UMC showed poor growth and high mortality. At 56 days, regardless of exposure, UMC were lightest, AMP birds were intermediate, and birds in all HAL treatments were heaviest. Similarities in results of exposed and nonexposed birds suggests that nonexposed birds became exposed through tracking of oocysts in the room. Lesion scores of those challenged with oocysts at 61 days showed that all treatments had adequate resistance to coccidiosis. At 20 weeks of age, combining both exposure methods, birds fed HAL (dosage 3.1.5 or 1.5, 1.5 mg/kg) were significantly heavier than UMC and AMP treatments.