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Responses of Growing and Finishing Turkey Toms to Dietary Lysine
Responses of Growing and Finishing Turkey Toms to Dietary Lysine DIRK LEHMANN,* MICHAEL PACK,t and HEINZ JEROCH* institute of Animal Nutrition, University of Halle-Wittenberg, P.O. Box 1, D-06099, Halle (Saale), Germany, and f Degussa AG, Applied Technology Feed Additives, P.O. Box 1345, D-63403 Hanau, Germany From 16 to 20 wk of age (13.1 to 18.5 kg live weight), the highest lysine level of 0.96% (3.0 g/Mcal ME) appeared to be insufficient to maximize weight gain. It is concluded, therefore, that the dietary lysine requirement of finishing turkey toms is 0.96% lysine or higher. In addition to the growth response, a marked increase in breast meat deposition in response to dietary lysine could be observed in finishing turkeys. Increasing dietary lysine decreased intramuscular fat content and grill loss and increased the protein level in breast meat.
(Key words: lysine, turkey, growth, breast meat, requirement) 1996 Poultry Science 75:711-718
INTRODUCTION Experimental data on amino acid requirements of growing and finishing turkeys is rather limited. Previous work has been done to estimate lysine requirements of growing and finishing turkeys with estimated requirements being variable over a wide range (Table 1). This variation may be due to differences in growth rate and feed intake as determined by genetic and environmental factors (Carlson et ah, 1969; Waibel and Noll, 1985; Plavnik and Hurwitz, 1993). Similarly, the recommendations published by numerous authorities show considerable variation (Table 2). Over the last few years the growth potential of commercial strains and their breast meat yield have continuously increased (Nestor et al., 1988). In Germany, British United Turkeys (BUT) Big 6 commercial toms reportedly weighed 14.5 to 16 kg at about 22 wk of age in 1982 (Bohn, 1983), which is considerably less than the reported range of 18.5 to 20.5 kg at the same age in 1993 (British United Turkeys, 1994). Recent investigations by Waldroup et al. (1993) and Lilburn and Emmerson (1993) indicated positive responses of growing turkeys to amino acid levels above the 1984 NRC specifications, which have not been changed too much with the new release (NRC, 1984, 1994). In an effort to fill the apparent gap of sound data for the current genetics of commercial turkeys, a growth study was conducted to investigate growth and carcass
quality responses of male turkeys to dietary lysine levels.
MATERIALS AND METHODS The response of male turkeys to dietary lysine was tested in two 4-wk periods from 8 to 12 and from 16 to 20 wk of age.
Birds and Housing One thousand five hundred BUT Big 6 toms from a commercial hatchery were grown from day-old to 5 wk of age. Then 540 birds of medium body weight were selected and equally distributed to 36 pens (6.3 m2) of 15 poults each. All poults were kept under the same environmental conditions in an isolated and artificially lighted house. Temperature was kept at 18 C from 8 to 12 wk, and 14 C from 16 to 20 wk of age. Light was provided for 12 h from 8 to 12 wk and for 18 h from 16 to 20 wk of age. From 5 wk of age onwards, chopped straw was used as litter. Pens were equipped with one hanging tube feeder and an automatic water device. Feed and water were offered for ad libitum consumption.
Diets Before the respective trial period started, the poults received commercial diets appropriate for the respective age. Prior to experimental diet formulation, the individual feedstuff batches were analyzed for their crude protein and amino acid content (Llames and Fontaine, 1994). The diets were formulated based on the analyzed amino acid
Received for publication September 6, 1995. Accepted for publication January 31, 1996.
711
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ABSTRACT The present study investigates the lysine requirements of British United Turkey (BUT) Big 6 turkey toms from 8 to 12 and from 16 to 20 wk of age. Growth, feed conversion, and carcass quality responses to increasing dietary lysine levels were measured. From 8 to 12 wk of age (4.0 to 8.8 kg live weight), about 1.20% (4.0 g/Mcal ME) lysine in the diet was found to be adequate to obtain optimum growth and feed conversion. Nitrogen retention also tended to increase with elevated dietary lysine levels in growing turkey toms.
712
LEHMANN ET AL. TABLE 1. Estimated requirements for dietary lysine in growing and finishing male turkeys Age
Temperature
Estimated requirement
(wk) 8 to 12
(C)
(g/Mcal ME) 4.00
23 6 26 20 6 12 16 16 to 20
2.81 2.22 2.16 2.28 2.11 2.16 2.33
(% of diet) 1.31 1.23 1.40 1.25 1.13 1.23 1.09 1.10 0.84 0.73 0.73 0.85 0.90 0.97 0.77 0.75 0.78 0.72 0.74
Turtle and Balloun (1974) Warnick (1979) Potter et al. (1981) Noll and Waibel (1989)
Nixey (1989)1 Plavnik and Hurwitz (1993) Jensen et al. (1976) Warnick (1979) Potter et al. (1981) Noll and Waibel (1989)
Nixey (1989)1
l i t e r a t u r e survey.
profiles. Crude fat, ash, starch, and sugar content of diets were analyzed according the methods described by Naumann and Bassler (1976). The experimental diets for the interval 8 to 12 wk of age consisted of a basal diet deficient in lysine, which was supplemented with 0, 0.1, 0.2, 0.3, 0.4. or 0.5% L-lysine (Table 3). Six pens each were allocated to one of six treatments, which included increasing levels ranging from 0.87 to 1.37% total lysine. From 16 to 20 wk of age, L-lysine additions of 0, 0.07, 0.14, 0.21, 0.28. or 0.35% to a basal diet containing 0.61% lysine were tested. Addition of L-lysine was confirmed by analysis of free lysine after extraction with diluted HC1 (National Feed Ingredients Association, 1991). The Llysine was supplied as Biolys®60,1 a commercial lysine source containing 46.8% free L-lysine as L-lysine sulfate. Diets were fed as pellets.
Experimental Procedure At the beginning of the respective experimental period, all poults were individually weighed. Pens were distributed among the various treatments ensuring a similar average body weight and weight distribution in each treatment. Feed was removed for 12 h before the poults were weighed. From 8 to 12 wk of age, weight gain for the 4-wk interval and weekly feed consumption per pen were recorded. Any bird that died or was culled was weighed and its weight was included in the calculation of weight gain and feed consumption per unit. Feed conversion per
1 Biolys®60: registered trademark Degussa AG; D-60287 Frankfurt, Germany.
pen was calculated as total feed consumed divided by the weight of live birds plus the weight of birds that died or were culled minus weight of all birds in the pen at start. At 16 wk of age, the 36 pens were reallocated to another six treatments of the second experimental period. This was done in such a way that, for example, the six pens of Treatment 1 were allocated to each one of the six new treatments. This procedure should avoid any pretreatment effects during the second experimental period (Nixey, 1989). At 20 wk and 3 d of age, 20 toms from each of three treatments (0.61, 0.75, and 0.96% dietary lysine), nearest the medium weight of the treatment, were selected and deprived of feed for 12 h. The birds were transported over 150 km from their house to the slaughterhouse. Arrival was 1 h before slaughter began. Each bird was weighed, killed by cutting the jugular vein after electric stunning, and allowed to bleed for approximately 3 min. The birds were then scalded at 57 C for 2 min, and placed in a rotary drum picker for 0.5 min. Head and feet were removed, and heart, liver, gizzard, and abdominal and viscera fat weights were recorded individually. The next day, after redetermination of the carcass weight, the left part of the carcass was cut into breast meat (Pectoralis major and Pectoralis minor), breast skin, thigh (separated into meat and skin and bone), drumstick, and wing. Breast meat samples were taken to determine tenderness, grill loss, protein, water, fat, and ash of the meat. The crude protein and crude fat content were determined according to Naumann and Bassler (1976) using the Kjeldahl N analysis or ether extraction after acidic pretreatment, respectively. Ash content in the meat samples was determined after oxidation of the organic substance with hydrogen peroxide.
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24 8 24 16 7
4.50 3.43 3.16 3.57 3.16 3.19 3.75 2.70 2.20 2.36 2.71
Investigator
LYSINE IN GROWING AND FINISHING TURKEYS TABLE 2. Recommendations for dietary lysine in growing and finishing male turkeys Recommendation
Authority
(wk)
(g/Mcal ME) (% of diet) 4.33 1.30 3.84 1.19 1.20 3.93 4.60 4.65 1.40 4.39 1.36 4.52 1.40 4.10 1.20 4.48 2.50 0.80 2.69 0.86 2.97 0.95 3.14 3.14 1.00 2.77 0.90 2.43 0.75 2.59
National Research Council (1994) Institute National de la Recherche Agronomique (1984) Cuddy Farms (1990) British United Turkeys Limited (1994) Degussa (1993) AEC (1987) Hybrid Turkey Inc. (1990) Moorgut Kartzfehn (1993) Jeroch (1995) National Research Council (1994) Institute National de la Recherche Agronomique (1984) Cuddy Farms (1990)1 British United Turkeys Limited (1994) Degussa (1993) Hybrid Turkey Inc. (1990) Moorgut Kartzfehn (1993) Jeroch (1995)
8 to 12
10 to 13
16 to 20
18 to 22
1
For British United Turkeys toms.
TABLE 3. Experimental basal diets Ingredients Corn (13% CP) Wheat (13.9% CP) Soybean meal (48% CP) Soybeans full-fat (35.7% CP) Sunflower meal (28.5% CP) Corn gluten (59.4% CP) Tapioca Corn starch Blended fat DL-methionine L-threonine L-tryptophan Monocalcium phosphate Calcium carbonate Salt Premix Analysis ME,3 kcal/kg Crude protein, % Lysine, % Met + Cys, % Threonine, % Arginine, % Calcium,4 % Available phosphorus,4 % Sodium,4 %
8 to 12 wk of age
16 to 20 wk of age
22.00 35.44 8.00 7.50 8.00 9.00 2.00
32.00 25.17
3.00 0.14 0.09 0.03 2.00 1.50 0.30 1.001
9.20 9.00 5.00 7.00 3.20 5.00 0.13 0.04 0.01 1.70 1.25 0.30 1.002
3,035 22.5 0.87 0.91 0.86 1.26 1.05 0.54 0.14
3,225 16.8 0.61 0.73 0.62 0.88 0.89 0.45 0.14
iSupplied per kilogram of diet: retinyl acetate, 18,000 IU; cholecalciferol, 3,500 IU; tocopherol, 30 mg; thiamin, 2 mg; riboflavin, 7 mg; cobalamin, 25 /ig; menadione, 2.5 mg; Ca-D-pantothenate, 17 mg; niacin, 60 mg; biotin, 150 /ig; folic acid, 1.5 mg; choline chloride, 1150 mg; iron, 50.1 mg; zinc, 60.8 mg; manganese, 80.6 mg; copper, 35 mg; cobalt, 1 mg; iodine, 1.1 mg; selenium, 0.35 mg; monensin-na, 66 mg; nitrofurazolidone, 50 mg; virginiamycin, 18 mg; antioxidant, 100 mg. Supplied per kilogram of diet: retinyl acetate, 10,000 IU; cholecalciferol, 3500 IU; tocopherol, 30 mg; thiamin, 2 mg; riboflavin, 7 mg; cobalamin, 25 /ig; menadione, 2.5 mg; Ca-D-Pantothenate, 17 mg; niacin, 60 mg; biotin, 150 /tg; folic acid, 1.5 mg; choline chloride, 1150 mg; iron, 50.1 mg; zinc, 60.8 mg; manganese, 80.6 mg; copper, 35 mg; cobalt, 1 mg; iodine, 1.1 mg; selenium, 0.35 mg; virginiamycin, 18 mg; antioxidant, 100 mg. Calculated from the ME content of individual ingredients according to World's Poultry Science Association (1989). 4 Calculated from the mineral content of individual ingredients according to CVB (1994).
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Age
LEHMANN ET AL.
714
Balance Study
5.00
Statistical Analysis Data were evaluated by one-way analysis of variance. Differences between treatments were tested for significance by using the Student-Newman-Keuls test (Snedecor and Cochran, 1980). The significance level was fixed at P < 0.05. The dose-related responses in weight gain and feed conversion to dietary lysine were modeled using the following exponential equation (Schutte and Pack, 1995):
4.75 4.50 4.25 4.00y=3.758
3.753.50 0.80
0.90
1.00
+
1.10
1.121*(1-^00*(x-°-87)) r 2 =0.98 1.20
1.30
1.40
Lysine (%)
2.35
Feed/gain y=2.313..231*(1-e-9-59*
2.30 H 2.25 2.20
2.15 2.10 2.05 2.00 0.80
0.90
1.00
1.10
1.20
1.30
1.40
Lysine (%) FIGURE 1. Growth and feed conversion responses of growing turkeys to dietary lysine (8 to 12 wk of age).
y = a + b x ( l - e-^x - d)) where y = weight gain or feed conversion; a = intercept (i.e., weight gain or feed conversion on basal diet); b = maximum response to dietary lysine level; c = curvature steepness; d = lysine content of basal diet (percentage); and x = dietary lysine content (percentage). The exponential model was fitted to the experimental data by means of the NLIN procedure of SAS® (SAS Institute, 1987). A modified Gauss-Newton iterative algorithm was employed to estimate the variables a, b, and c simultaneously. Nitrogen retention data from the balance study were subjected to regression analysis that tested linear, quadratic, and exponential models. The REG and NLIN procedures of SAS® were used for this purpose (SAS Institute, 1987).
RESULTS During both experimental periods, the poults performed very well and consistently responded to increasing dietary lysine (Table 4). The poor growth rate and feed efficiency of turkey toms fed the unsupplemented basal diets in both periods indicated that these diets were indeed deficient in lysine. Growth and feed conversion responses are presented in Figures 1 and 2 with exponential curves fitted to the data. Starting from
an initial body mass of 4.0 kg at 56 d of age, weight gain to 84 d of age was improved from 3.8 up to 4.8 kg, corresponding to 135 or 172 g/d, respectively, by increasing the dietary lysine content. Growth was numerically maximum at 1.27% dietary lysine. Feed conversion was significantly improved up to 1.07% lysine. Feed intake increased along with increasing dietary lysine content up to 1.17% lysine. In the finisher period from 16 to 20 wk of age, growth increased almost linearly with increasing lysine content (Figure 2). With an initial body weight of 13.1 kg at 112 d of age, weight gain to 140 d of age was about 4.5 kg/d or 162 g/d with the basal diet, and increased up to 5.4/d kg or 194 g/d at 0.96% lysine. The response in feed conversion essentially paralleled the growth response. The growth responses to dietary lysine were accompanied by a significant increase in breast meat deposition (Table 5). The highest breast meat proportion of 31.8% was obtained at 0.96% lysine from 16 to 20 wk of age. The breast meat samples from the birds fed the lowest dietary lysine level had significantly higher grill losses, higher fat content, and lower protein content (Table 5). The protein content was correspondingly higher with the diets containing 0.75 or 0.96% lysine. There was no consistent trend in meat tenderness connected with the changes in protein and fat content of breast meat.
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Twenty-five turkeys were raised to 10 wk of age and then used to perform balance studies with the diets fed between 8 and 12 wk of age. Three or four toms with body weights between 6.4 and 7.1 kg were used per treatment. They were fed on a restrictive schedule allowing 310 g of feed per bird per d, which was slightly lower than the ad libitum intake of birds in the corresponding growth study. The procedures followed the schedule established by the German Society for Nutrition Physiology of Domestic Animals (GEH, 1973). The poults were housed individually in cages and excreta were collected twice daily in a plastic tray with cover and frozen at -18 C during the 5-d collection period. After finishing the trial, the excreta samples of each bird were thawed, weighed, mixed, freeze-dried, reweighed, and ground before analysis for N.
Weight gain (kg)
715
LYSINE IN GROWING AND FINISHING TURKEYS 5.50
Weight gain (kg)
6.5
N retention (g/d)
6.0
5.25-
5.5
5.00-
5.0-1
4.75-
4.5
4.50
1.176*(1-G*06*(X-°-61))
y=4.528 +
4.25 0.60
r 2 - 0.99 0.70
0.80
0.90
4.0
y = -2.287 + 4.197*x - .558*x'
3.5
r 2 = 0.47
3.0
1.00
2.4
Lysine (%)
2.6 2.8
3.0
I
I
I
t
3.2
3.4
3.6
3.8
4.0
4.2
Lysine intake (g/d)
0.60
o ooa
n*~*y*
-6.64*(X-0.61)
y=3.328 - .242*(1-e r 2 = 0.89
0.70
0.80
0.90
)
1.00
Lysine (%) FIGURE 2. Growth and feed conversion responses of finishing turkeys to dietary lysine (16 to 20 wk of age).
In an isocaloric and isonitrogenous diet, increasing dietary lysine tended to result in increased nitrogen retention (Figure 3). The response, although varying among individual poults, could best be characterized by a quadratic model, which gave an estimated maximum of protein retention at an intake of 3.75 g lysine/d. The exponential model gave a poor fit to the data.
DISCUSSION In the present experiments, daily weight gain was higher than in earlier reports about lysine requirements of turkey toms (Jensen et al, 1976; Kramer and Waibel, 1979; Potter et al, 1981; Hurwitz et al, 1983; Noll and Waibel, 1989; Plavnik and Hurwitz, 1993). From 8 to 12 wk of age, a lysine level in the range of 1.20% in the diet was found to be adequate for optimum weight gain and feed conversion. From the exponential response functions illustrated in Figure 1, the dietary lysine level to obtain 96, 97, or 98% of maximum growth would be estimated at 1.16% (3.8 g/Mcal), 1.21% (4.0 g/ Meal), or 1.28% (4.2 g/Mcal), respectively. These results fall within the range of estimates reported in Table 1 and correlate closely with the 1994 NRC specification. Daily weight gain was 19, 46, 59, and 61% higher than that reported by Plavnik and Hurwitz (1993), Noll and
FIGURE 3. Nitrogen retention in growing turkeys as affected by dietary lysine level (5-d balance study in 10-wk-old poults).
Waibel (1989), Turtle and Balloun (1974), and Potter et al. (1981), respectively. The present data also confirm most of the current practical recommendations in the range of 4.4 to 4.6 g lysine/Mcal ME, if one considers that these recommendations typically include some safety margin for commercial feed production. The data on N retention (Figure 3) essentially confirm the growth data obtained from 8 to 12 wk. The response in N retention, however, was less than the growth response, which is probably due to the restrictive feeding schedule during the balance study. Thus, birds on the higher lysine supply could not increase their feed intake along with accelerated growth as could their counterparts in the growth experiment. The present data should certainly be regarded as a rough estimate of the effects of lysine on N retention, because the limited number of observations and the high variability gave only a fairly inconsistent fit of regression models (r2 = 0.47 for the quadratic curve, r2 = 0.40 for the linear model). Nevertheless, the experimental procedure employed here may allow for some rough judgment of bird responses to dietary changes without the need to run large-scale feeding trials. From 16 to 20 wk of age, daily weight gain was 28, 73, and 106% higher than reported by Noll and Waibel (1989), Jensen et al. (1976), and Potter et al. (1981), respectively. Within the range of lysine levels tested, highest weight gain occurred at 5.8 g lysine intake/d. The highest dietary level of 0.96% lysine (3.0 g/Mcal ME) appeared to be inadequate to maximize growth. These results essentially confirm the results of Potter et al. (1981), but considerably exceed all other requirement estimates listed in Table 1 and also exceed the 1994 NRC specifications by 20%. The results indicate that faster growing turkeys may have higher requirements than slower growing strains (Waibel and Noll, 1985), not only in terms of lysine intake but also in terms of dietary lysine concentration. This may be the case especially with a late-maturing strain such as the BUT Big 6 bird, which continues to grow at a very high rate beyond a body weight of 15 or 16 kg. Differences in growth
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3.40 3.353.303.253.203.153.103.053.00-
Feed/gain
716
LEHMANN ET AL. TABLE 4. Growth performance of turkey toms fed graded levels of lysine
Age
Lysine
(wk)
(%)
Weight gain
Lysine intake
Feed intake
Feed:gain (kg:kg)
(g/d)
8 to 12
0.87 0.97 1.07 1.17 1.27 1.37 Pooled SEM
2.71" 3.17b 3.62' 4.17d 4.52= 4.88f 0.13
135.2" 149.2b 163.3' 170.2^ 171.6d 169.6' d 2.4
311.7* 327.2b 338.5b 356.0' 356.0' 355.9' 3.3
2.307' 2.204b 2.074a 2.091' 2.075* 2.115* 0.015
16 to 20
0.61 0.68 0.75 0.82 0.89 0.96 Pooled SEM
3.28" 3.77b 4.31' 4.81d 5.25* 5.80f 0.15
161.8* 171.2* 182.0 b ' 183.7b' 190.9' 193.6' 2.5
538.1" 554.9*b 574.4* 587.0b 590.4b 604.3b 6.1
3.328b 3.241* 3.158*b 3.193* 3.082* 3.122* 0.023
Means within columns within age with no common superscript differ significantly (P < 0.05).
pattern between strains are most likely to influence the nutrient requirements in specific feeding periods (Leeson and Caston, 1991). In general, it is relatively difficult to relate the present data from the finisher phase to similar work done in poults of no more than 12 to 13 kg body weight at 18 wk of age (Moran et al, 1992; Waldroup et al, 1993; Sell et al, 1994). The present data support commercial recommendations around 3 g lysine/Mcal ME as advocated by Cuddy Farms (1990), BUT (1994), and Degussa (1993).
Carcass quality correlated to some degree with the growth rate observed during the finishing period. Birds on the highest lysine level of 0.96% had a considerably higher breast meat portion than was found in carcasses on the deficient and intermediate dietary lysine level. The same was true for carcass yield. One could speculate that turkeys may first respond with better growth when dietary lysine is raised, and would only show a breast meat response at dietary lysine levels allowing close-tomaximum growth. It is interesting to compare the breast
TABLE 5. Impact of dietary lysine 16 to 20 wk of age on carcass composition and meat quality in finishing turkeys Dietary lysine
Variable
0.61%
0.75%
0.96%
SEM
Body weight at slaughter, kg Dressing,1 % Carcass fat, % BW Inner organs (liver, heart, gizzard), % BW Carcass parts, % of carcass weight Breast2 Meat Skin Thighs2 Meat Skin Drumsticks Wings Meat quality (breast meat) Grill loss,3 % Tenderness4 Water content, % Protein content, % DM Fat content, % DM Ash content, % DM
17.81* 83.96*b 2.12 1.99*
18.21b 83.56* 2.50 1.78b
18.45' 84.46b 2.25 1.74b
0.05 0.11 0.08 0.02
33.46* 30.62* 2.85 16.62 13.75* 1.62 12.81 10.50
34.00*b 30.96*b 3.04 16.21 13.38*b 1.58 12.76 10.45
34.59b 31.79b 2.80 16.04 13.25b 1.57 12.94 10.45
0.19 0.19 0.09 0.12 0.08 0.07 0.09 0.08
32.41* 2.84 74.38 89.10* 6.87* 4.23
28.91b 2.64 73.75 91.52b 4.84b 4.25
29.64b 3.13 74.67 92.68b 4.03b 4.40
0.44 0.11 0.19 0.50 0.44 0.06
*"'Means within rows with no common superscript differ significantly (P < 0.05). deluding liver, heart, and gizzard. Excluding bones. 3 Grilled for 7.5 min to an internal meat temperature of 72 C; each sample wrapped in aluminum foil. 4 Using Warner-Bratzler-shear (G-R-Eleg Mfg. Co., New York, NY).
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a_f
LYSINE IN GROWING AND FINISHING TURKEYS
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Degussa, 1993. Amino Acid Recommendations for Poultry. Degussa AG, Hanau, Germany. Gesellschaft der Ernahrungsphysiologie der Haustiere, 1973. Richtlinien zur Durchfuhrung von Bilanzversuchen mit Huhnern. Arch. Geflugelkd. 2:49-57 Hurwitz, S., J. Plavnik, I. Bengal, H. Talpaz, and J. Bartov, 1983. The amino acid requirements of growing turkeys. 2. Experimental validation of model—calculated requirements for sulfur amino acids and lysine. Poultry Sci. 62: 2387-2393. Hybrid Turkeys, 1990. Feeding Programs. Kitchener, ON, Canada. Institut National de la Recherche Agronomique, 1984. L'Alimentation des Animaux Monogastriques. Institut National de la Recherche Agronomique, Paris, France. Jensen, L. S., B. Manning, L. Falen, and J. McGinnis, 1976. Lysine needs of rapidly growing turkeys from 12-22 weeks of age. Poultry Sci. 55:1394-1400. Jeroch, H., 1995. Faustzahlen zur Geflugelfutterung. Pages 85-107 in: Jahrbuch fur die Geflugelfutterung 1995. J. Petersen, ed. Verlag Eugen Ulmer, Stuttgart, Germany. Kramer, S. L., and P. E. Waibel, 1979. Study of lysine requirement of growing turkeys at varying ambient temperatures. Poultry Sci. 58:1075. (Abstr.) Leeson, S., and L. J. Caston, 1991. Response of two strains of turkey hens to various protein and energy feeding programs. Poultry Sci. 70:1739-1747. Lilburn, M. S., and D. Emmerson, 1993. The influence of differences in dietary amino acids during the early growing period on growth and development of Nicholas and British United Turkey toms. Poultry Sci. 72:1722-1730. Llames, C, and J. Fontaine, 1994. Determination of amino acids in feeds: collaborative study. J. AOAC Int. 77:1362-1402. Moorgut Kartzfehn, 1993. Informationen zur Putenmast. Bosel, Germany. Moran, E. T., K. K. Krueger, and N. Acar, 1992. Response of male turkeys hatched from first-cycle and force-molted breeder hens to a regimen providing progressive feeds by weight and value of increased lysine prior marketing. Poultry Sci. 71:1891-1899. National Feed Ingredients Association, 1991. Supplemented amino acids (Methionine and lysine). Pages 71-72 in: NFIA Laboratory Methods Compendium. Vol. 3. National Feed Ingredients Association, West Des Moines, IA. National Research Council, 1984. Nutrient Requirements of Poultry. 8th rev. ed. National Academy Press, Washington, DC. National Research Council, 1994. Nutrient Requirements of Poultry. 9th rev. ed. National Academy Press, Washington, DC. Naumann, C, and R. Bassler, 1976. Verband Deutscher Landwirtschaftlicher Untersuchungs- und Forschungsanstalten. Methodenbuch Band III. Die chemische Untersuchung von Futtermitteln. 3. Erganzungslieferung 1993, VDLUFA-Verlag, Darmstadt, Germany. Nestor, K. E., W. L. Bacon, G. B. Havenstein, Y. M. Saif, and P. A. Renner, 1988. Carcass traits of turkeys from lines selected for increased growth rate or increased shank width. Poultry Sci. 67:1660-1667. Nixey, C, 1989. Nutritional responses of growing Turkeys. Pages 183-189 in: Recent Advances in Turkey Science. C. Nixey and T. C. Grey, ed. Butterworth, London, UK. Noll, S. L., and P. E. Waibel, 1989. Lysine requirements of growing turkeys in various temperature environments. Poultry Sci. 68:781-794.
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meat yield data obtained in this study to a recent survey by Brake et al. (1995) of U.S. commercial turkeys. Carcasses from birds of u p to 17.6 kg body weight were cut up and regression equations were estimated to calculate the weight of various carcass parts depending on live body weight. Using their regressions for the weight of the P. major plus P. minor, one could expect about 4,300 g of breast meat in BUT toms of 18.5 kg. The actual breast meat yield in the present group receiving 0.96% dietary lysine was 4,851 g, which might, disregarding possible differences in cutting procedure, indicate the potential of the BUT stock to express even higher yield than currently seen under field conditions. However, because this study was limited to three treatment groups and the relatively small number of 20 carcasses per diet, the present data on yield and carcass composition need to be interpreted carefully. Interestingly, an effect of dietary lysine on carcass fatness was not detected, which may be the net effect of increased fat with higher body weight and less fat with more adequate lysine in the diet. The results of meat quality determination showed that with increasing dietary lysine the fat content in the breast meat decreased, although there was virtually no difference in total carcass fat content. With decreasing fat content, breast meat protein increased proportionately. The higher fat content in the breast meat of birds fed the unsupplemented diet may have been the reason for the higher grill loss in breast meat samples obtained from those carcasses. Meat tenderness as measured by shear force did not show any consistent change along with the differences observed in protein and fat content of the meat. Thus there is probably no negative impact of improved leanness on meat quality for the consumer.
717
718
LEHMANN ET AL.
Plavnik, I. and S. Hurwitz, 1993. Amino acids and protein requirement in turkeys. Pages 236-243 in: 9th European Symposium on Poultry Nutrition. Jelenia G6ra, Poland. Potter, L. M., J. R. Shelton, and J. P. McCarthy, 1981. Lysine and protein requirements of growing turkeys. Poultry Sci. 60:2678-2686. SAS Institute, 1987. SAS/STAT® User's Guide. SAS Institute Inc., Cary, NC. Schutte, J. B., and M. Pack, 1995. Sulfur amino acid requirement of broiler chicks from fourteen to thirty-eight days of age. 1. Performance and carcass yield. Poultry Sci. 74:480-i87. Sell, J. L., M. J. Jeffrey, and B. J. Kerr, 1994. Influence of amino acid supplementation of low-protein diets and metabolizable energy feeding sequences on performance and carcass composition of toms. Poultry Sci. 73:1867-1880.
Snedecor, G. W., and W. G. Cochran, 1980. Statistical methods. 7th ed. The Iowa State University Press, Ames, IA. Tuttle, W. L., and S. L. Balloun, 1974. Lysine requirements of starting and growing turkeys. Poultry Sci. 53:1698-1704. Waibel, P. E., and S. L. Noll, 1985. Amino acid requirements in turkeys. Feed Manage. 38:22-32. Waldroup, P. W., M. H. Adams, and A. L. Waldroup, 1993. Effects of amino acid restriction during starter and grower periods on subsequent performance and incidence of leg disorders in male large white turkeys. Poultry Sci. 72: 816-828. Warnick, R. E., 1979. Lysine levels in turkey grower diets. Poultry Sci. 58:1120. (Abstr.) World's Poultry Science Association, 1989. European Table of Energy Values for Poultry Feedstuffs. 3rd ed. Working Group No. 2 of the European Branch, World's Poultry Science Association, Beekbergen, The Netherlands. Downloaded from http://ps.oxfordjournals.org/ at Northern Arizona University on May 31, 2015
(Key words: lysine, turkey, growth, breast meat, requirement) 1996 Poultry Science 75:711-718
INTRODUCTION Experimental data on amino acid requirements of growing and finishing turkeys is rather limited. Previous work has been done to estimate lysine requirements of growing and finishing turkeys with estimated requirements being variable over a wide range (Table 1). This variation may be due to differences in growth rate and feed intake as determined by genetic and environmental factors (Carlson et ah, 1969; Waibel and Noll, 1985; Plavnik and Hurwitz, 1993). Similarly, the recommendations published by numerous authorities show considerable variation (Table 2). Over the last few years the growth potential of commercial strains and their breast meat yield have continuously increased (Nestor et al., 1988). In Germany, British United Turkeys (BUT) Big 6 commercial toms reportedly weighed 14.5 to 16 kg at about 22 wk of age in 1982 (Bohn, 1983), which is considerably less than the reported range of 18.5 to 20.5 kg at the same age in 1993 (British United Turkeys, 1994). Recent investigations by Waldroup et al. (1993) and Lilburn and Emmerson (1993) indicated positive responses of growing turkeys to amino acid levels above the 1984 NRC specifications, which have not been changed too much with the new release (NRC, 1984, 1994). In an effort to fill the apparent gap of sound data for the current genetics of commercial turkeys, a growth study was conducted to investigate growth and carcass
quality responses of male turkeys to dietary lysine levels.
MATERIALS AND METHODS The response of male turkeys to dietary lysine was tested in two 4-wk periods from 8 to 12 and from 16 to 20 wk of age.
Birds and Housing One thousand five hundred BUT Big 6 toms from a commercial hatchery were grown from day-old to 5 wk of age. Then 540 birds of medium body weight were selected and equally distributed to 36 pens (6.3 m2) of 15 poults each. All poults were kept under the same environmental conditions in an isolated and artificially lighted house. Temperature was kept at 18 C from 8 to 12 wk, and 14 C from 16 to 20 wk of age. Light was provided for 12 h from 8 to 12 wk and for 18 h from 16 to 20 wk of age. From 5 wk of age onwards, chopped straw was used as litter. Pens were equipped with one hanging tube feeder and an automatic water device. Feed and water were offered for ad libitum consumption.
Diets Before the respective trial period started, the poults received commercial diets appropriate for the respective age. Prior to experimental diet formulation, the individual feedstuff batches were analyzed for their crude protein and amino acid content (Llames and Fontaine, 1994). The diets were formulated based on the analyzed amino acid
Received for publication September 6, 1995. Accepted for publication January 31, 1996.
711
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ABSTRACT The present study investigates the lysine requirements of British United Turkey (BUT) Big 6 turkey toms from 8 to 12 and from 16 to 20 wk of age. Growth, feed conversion, and carcass quality responses to increasing dietary lysine levels were measured. From 8 to 12 wk of age (4.0 to 8.8 kg live weight), about 1.20% (4.0 g/Mcal ME) lysine in the diet was found to be adequate to obtain optimum growth and feed conversion. Nitrogen retention also tended to increase with elevated dietary lysine levels in growing turkey toms.
712
LEHMANN ET AL. TABLE 1. Estimated requirements for dietary lysine in growing and finishing male turkeys Age
Temperature
Estimated requirement
(wk) 8 to 12
(C)
(g/Mcal ME) 4.00
23 6 26 20 6 12 16 16 to 20
2.81 2.22 2.16 2.28 2.11 2.16 2.33
(% of diet) 1.31 1.23 1.40 1.25 1.13 1.23 1.09 1.10 0.84 0.73 0.73 0.85 0.90 0.97 0.77 0.75 0.78 0.72 0.74
Turtle and Balloun (1974) Warnick (1979) Potter et al. (1981) Noll and Waibel (1989)
Nixey (1989)1 Plavnik and Hurwitz (1993) Jensen et al. (1976) Warnick (1979) Potter et al. (1981) Noll and Waibel (1989)
Nixey (1989)1
l i t e r a t u r e survey.
profiles. Crude fat, ash, starch, and sugar content of diets were analyzed according the methods described by Naumann and Bassler (1976). The experimental diets for the interval 8 to 12 wk of age consisted of a basal diet deficient in lysine, which was supplemented with 0, 0.1, 0.2, 0.3, 0.4. or 0.5% L-lysine (Table 3). Six pens each were allocated to one of six treatments, which included increasing levels ranging from 0.87 to 1.37% total lysine. From 16 to 20 wk of age, L-lysine additions of 0, 0.07, 0.14, 0.21, 0.28. or 0.35% to a basal diet containing 0.61% lysine were tested. Addition of L-lysine was confirmed by analysis of free lysine after extraction with diluted HC1 (National Feed Ingredients Association, 1991). The Llysine was supplied as Biolys®60,1 a commercial lysine source containing 46.8% free L-lysine as L-lysine sulfate. Diets were fed as pellets.
Experimental Procedure At the beginning of the respective experimental period, all poults were individually weighed. Pens were distributed among the various treatments ensuring a similar average body weight and weight distribution in each treatment. Feed was removed for 12 h before the poults were weighed. From 8 to 12 wk of age, weight gain for the 4-wk interval and weekly feed consumption per pen were recorded. Any bird that died or was culled was weighed and its weight was included in the calculation of weight gain and feed consumption per unit. Feed conversion per
1 Biolys®60: registered trademark Degussa AG; D-60287 Frankfurt, Germany.
pen was calculated as total feed consumed divided by the weight of live birds plus the weight of birds that died or were culled minus weight of all birds in the pen at start. At 16 wk of age, the 36 pens were reallocated to another six treatments of the second experimental period. This was done in such a way that, for example, the six pens of Treatment 1 were allocated to each one of the six new treatments. This procedure should avoid any pretreatment effects during the second experimental period (Nixey, 1989). At 20 wk and 3 d of age, 20 toms from each of three treatments (0.61, 0.75, and 0.96% dietary lysine), nearest the medium weight of the treatment, were selected and deprived of feed for 12 h. The birds were transported over 150 km from their house to the slaughterhouse. Arrival was 1 h before slaughter began. Each bird was weighed, killed by cutting the jugular vein after electric stunning, and allowed to bleed for approximately 3 min. The birds were then scalded at 57 C for 2 min, and placed in a rotary drum picker for 0.5 min. Head and feet were removed, and heart, liver, gizzard, and abdominal and viscera fat weights were recorded individually. The next day, after redetermination of the carcass weight, the left part of the carcass was cut into breast meat (Pectoralis major and Pectoralis minor), breast skin, thigh (separated into meat and skin and bone), drumstick, and wing. Breast meat samples were taken to determine tenderness, grill loss, protein, water, fat, and ash of the meat. The crude protein and crude fat content were determined according to Naumann and Bassler (1976) using the Kjeldahl N analysis or ether extraction after acidic pretreatment, respectively. Ash content in the meat samples was determined after oxidation of the organic substance with hydrogen peroxide.
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24 8 24 16 7
4.50 3.43 3.16 3.57 3.16 3.19 3.75 2.70 2.20 2.36 2.71
Investigator
LYSINE IN GROWING AND FINISHING TURKEYS TABLE 2. Recommendations for dietary lysine in growing and finishing male turkeys Recommendation
Authority
(wk)
(g/Mcal ME) (% of diet) 4.33 1.30 3.84 1.19 1.20 3.93 4.60 4.65 1.40 4.39 1.36 4.52 1.40 4.10 1.20 4.48 2.50 0.80 2.69 0.86 2.97 0.95 3.14 3.14 1.00 2.77 0.90 2.43 0.75 2.59
National Research Council (1994) Institute National de la Recherche Agronomique (1984) Cuddy Farms (1990) British United Turkeys Limited (1994) Degussa (1993) AEC (1987) Hybrid Turkey Inc. (1990) Moorgut Kartzfehn (1993) Jeroch (1995) National Research Council (1994) Institute National de la Recherche Agronomique (1984) Cuddy Farms (1990)1 British United Turkeys Limited (1994) Degussa (1993) Hybrid Turkey Inc. (1990) Moorgut Kartzfehn (1993) Jeroch (1995)
8 to 12
10 to 13
16 to 20
18 to 22
1
For British United Turkeys toms.
TABLE 3. Experimental basal diets Ingredients Corn (13% CP) Wheat (13.9% CP) Soybean meal (48% CP) Soybeans full-fat (35.7% CP) Sunflower meal (28.5% CP) Corn gluten (59.4% CP) Tapioca Corn starch Blended fat DL-methionine L-threonine L-tryptophan Monocalcium phosphate Calcium carbonate Salt Premix Analysis ME,3 kcal/kg Crude protein, % Lysine, % Met + Cys, % Threonine, % Arginine, % Calcium,4 % Available phosphorus,4 % Sodium,4 %
8 to 12 wk of age
16 to 20 wk of age
22.00 35.44 8.00 7.50 8.00 9.00 2.00
32.00 25.17
3.00 0.14 0.09 0.03 2.00 1.50 0.30 1.001
9.20 9.00 5.00 7.00 3.20 5.00 0.13 0.04 0.01 1.70 1.25 0.30 1.002
3,035 22.5 0.87 0.91 0.86 1.26 1.05 0.54 0.14
3,225 16.8 0.61 0.73 0.62 0.88 0.89 0.45 0.14
iSupplied per kilogram of diet: retinyl acetate, 18,000 IU; cholecalciferol, 3,500 IU; tocopherol, 30 mg; thiamin, 2 mg; riboflavin, 7 mg; cobalamin, 25 /ig; menadione, 2.5 mg; Ca-D-pantothenate, 17 mg; niacin, 60 mg; biotin, 150 /ig; folic acid, 1.5 mg; choline chloride, 1150 mg; iron, 50.1 mg; zinc, 60.8 mg; manganese, 80.6 mg; copper, 35 mg; cobalt, 1 mg; iodine, 1.1 mg; selenium, 0.35 mg; monensin-na, 66 mg; nitrofurazolidone, 50 mg; virginiamycin, 18 mg; antioxidant, 100 mg. Supplied per kilogram of diet: retinyl acetate, 10,000 IU; cholecalciferol, 3500 IU; tocopherol, 30 mg; thiamin, 2 mg; riboflavin, 7 mg; cobalamin, 25 /ig; menadione, 2.5 mg; Ca-D-Pantothenate, 17 mg; niacin, 60 mg; biotin, 150 /tg; folic acid, 1.5 mg; choline chloride, 1150 mg; iron, 50.1 mg; zinc, 60.8 mg; manganese, 80.6 mg; copper, 35 mg; cobalt, 1 mg; iodine, 1.1 mg; selenium, 0.35 mg; virginiamycin, 18 mg; antioxidant, 100 mg. Calculated from the ME content of individual ingredients according to World's Poultry Science Association (1989). 4 Calculated from the mineral content of individual ingredients according to CVB (1994).
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Age
LEHMANN ET AL.
714
Balance Study
5.00
Statistical Analysis Data were evaluated by one-way analysis of variance. Differences between treatments were tested for significance by using the Student-Newman-Keuls test (Snedecor and Cochran, 1980). The significance level was fixed at P < 0.05. The dose-related responses in weight gain and feed conversion to dietary lysine were modeled using the following exponential equation (Schutte and Pack, 1995):
4.75 4.50 4.25 4.00y=3.758
3.753.50 0.80
0.90
1.00
+
1.10
1.121*(1-^00*(x-°-87)) r 2 =0.98 1.20
1.30
1.40
Lysine (%)
2.35
Feed/gain y=2.313..231*(1-e-9-59*
2.30 H 2.25 2.20
2.15 2.10 2.05 2.00 0.80
0.90
1.00
1.10
1.20
1.30
1.40
Lysine (%) FIGURE 1. Growth and feed conversion responses of growing turkeys to dietary lysine (8 to 12 wk of age).
y = a + b x ( l - e-^x - d)) where y = weight gain or feed conversion; a = intercept (i.e., weight gain or feed conversion on basal diet); b = maximum response to dietary lysine level; c = curvature steepness; d = lysine content of basal diet (percentage); and x = dietary lysine content (percentage). The exponential model was fitted to the experimental data by means of the NLIN procedure of SAS® (SAS Institute, 1987). A modified Gauss-Newton iterative algorithm was employed to estimate the variables a, b, and c simultaneously. Nitrogen retention data from the balance study were subjected to regression analysis that tested linear, quadratic, and exponential models. The REG and NLIN procedures of SAS® were used for this purpose (SAS Institute, 1987).
RESULTS During both experimental periods, the poults performed very well and consistently responded to increasing dietary lysine (Table 4). The poor growth rate and feed efficiency of turkey toms fed the unsupplemented basal diets in both periods indicated that these diets were indeed deficient in lysine. Growth and feed conversion responses are presented in Figures 1 and 2 with exponential curves fitted to the data. Starting from
an initial body mass of 4.0 kg at 56 d of age, weight gain to 84 d of age was improved from 3.8 up to 4.8 kg, corresponding to 135 or 172 g/d, respectively, by increasing the dietary lysine content. Growth was numerically maximum at 1.27% dietary lysine. Feed conversion was significantly improved up to 1.07% lysine. Feed intake increased along with increasing dietary lysine content up to 1.17% lysine. In the finisher period from 16 to 20 wk of age, growth increased almost linearly with increasing lysine content (Figure 2). With an initial body weight of 13.1 kg at 112 d of age, weight gain to 140 d of age was about 4.5 kg/d or 162 g/d with the basal diet, and increased up to 5.4/d kg or 194 g/d at 0.96% lysine. The response in feed conversion essentially paralleled the growth response. The growth responses to dietary lysine were accompanied by a significant increase in breast meat deposition (Table 5). The highest breast meat proportion of 31.8% was obtained at 0.96% lysine from 16 to 20 wk of age. The breast meat samples from the birds fed the lowest dietary lysine level had significantly higher grill losses, higher fat content, and lower protein content (Table 5). The protein content was correspondingly higher with the diets containing 0.75 or 0.96% lysine. There was no consistent trend in meat tenderness connected with the changes in protein and fat content of breast meat.
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Twenty-five turkeys were raised to 10 wk of age and then used to perform balance studies with the diets fed between 8 and 12 wk of age. Three or four toms with body weights between 6.4 and 7.1 kg were used per treatment. They were fed on a restrictive schedule allowing 310 g of feed per bird per d, which was slightly lower than the ad libitum intake of birds in the corresponding growth study. The procedures followed the schedule established by the German Society for Nutrition Physiology of Domestic Animals (GEH, 1973). The poults were housed individually in cages and excreta were collected twice daily in a plastic tray with cover and frozen at -18 C during the 5-d collection period. After finishing the trial, the excreta samples of each bird were thawed, weighed, mixed, freeze-dried, reweighed, and ground before analysis for N.
Weight gain (kg)
715
LYSINE IN GROWING AND FINISHING TURKEYS 5.50
Weight gain (kg)
6.5
N retention (g/d)
6.0
5.25-
5.5
5.00-
5.0-1
4.75-
4.5
4.50
1.176*(1-G*06*(X-°-61))
y=4.528 +
4.25 0.60
r 2 - 0.99 0.70
0.80
0.90
4.0
y = -2.287 + 4.197*x - .558*x'
3.5
r 2 = 0.47
3.0
1.00
2.4
Lysine (%)
2.6 2.8
3.0
I
I
I
t
3.2
3.4
3.6
3.8
4.0
4.2
Lysine intake (g/d)
0.60
o ooa
n*~*y*
-6.64*(X-0.61)
y=3.328 - .242*(1-e r 2 = 0.89
0.70
0.80
0.90
)
1.00
Lysine (%) FIGURE 2. Growth and feed conversion responses of finishing turkeys to dietary lysine (16 to 20 wk of age).
In an isocaloric and isonitrogenous diet, increasing dietary lysine tended to result in increased nitrogen retention (Figure 3). The response, although varying among individual poults, could best be characterized by a quadratic model, which gave an estimated maximum of protein retention at an intake of 3.75 g lysine/d. The exponential model gave a poor fit to the data.
DISCUSSION In the present experiments, daily weight gain was higher than in earlier reports about lysine requirements of turkey toms (Jensen et al, 1976; Kramer and Waibel, 1979; Potter et al, 1981; Hurwitz et al, 1983; Noll and Waibel, 1989; Plavnik and Hurwitz, 1993). From 8 to 12 wk of age, a lysine level in the range of 1.20% in the diet was found to be adequate for optimum weight gain and feed conversion. From the exponential response functions illustrated in Figure 1, the dietary lysine level to obtain 96, 97, or 98% of maximum growth would be estimated at 1.16% (3.8 g/Mcal), 1.21% (4.0 g/ Meal), or 1.28% (4.2 g/Mcal), respectively. These results fall within the range of estimates reported in Table 1 and correlate closely with the 1994 NRC specification. Daily weight gain was 19, 46, 59, and 61% higher than that reported by Plavnik and Hurwitz (1993), Noll and
FIGURE 3. Nitrogen retention in growing turkeys as affected by dietary lysine level (5-d balance study in 10-wk-old poults).
Waibel (1989), Turtle and Balloun (1974), and Potter et al. (1981), respectively. The present data also confirm most of the current practical recommendations in the range of 4.4 to 4.6 g lysine/Mcal ME, if one considers that these recommendations typically include some safety margin for commercial feed production. The data on N retention (Figure 3) essentially confirm the growth data obtained from 8 to 12 wk. The response in N retention, however, was less than the growth response, which is probably due to the restrictive feeding schedule during the balance study. Thus, birds on the higher lysine supply could not increase their feed intake along with accelerated growth as could their counterparts in the growth experiment. The present data should certainly be regarded as a rough estimate of the effects of lysine on N retention, because the limited number of observations and the high variability gave only a fairly inconsistent fit of regression models (r2 = 0.47 for the quadratic curve, r2 = 0.40 for the linear model). Nevertheless, the experimental procedure employed here may allow for some rough judgment of bird responses to dietary changes without the need to run large-scale feeding trials. From 16 to 20 wk of age, daily weight gain was 28, 73, and 106% higher than reported by Noll and Waibel (1989), Jensen et al. (1976), and Potter et al. (1981), respectively. Within the range of lysine levels tested, highest weight gain occurred at 5.8 g lysine intake/d. The highest dietary level of 0.96% lysine (3.0 g/Mcal ME) appeared to be inadequate to maximize growth. These results essentially confirm the results of Potter et al. (1981), but considerably exceed all other requirement estimates listed in Table 1 and also exceed the 1994 NRC specifications by 20%. The results indicate that faster growing turkeys may have higher requirements than slower growing strains (Waibel and Noll, 1985), not only in terms of lysine intake but also in terms of dietary lysine concentration. This may be the case especially with a late-maturing strain such as the BUT Big 6 bird, which continues to grow at a very high rate beyond a body weight of 15 or 16 kg. Differences in growth
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3.40 3.353.303.253.203.153.103.053.00-
Feed/gain
716
LEHMANN ET AL. TABLE 4. Growth performance of turkey toms fed graded levels of lysine
Age
Lysine
(wk)
(%)
Weight gain
Lysine intake
Feed intake
Feed:gain (kg:kg)
(g/d)
8 to 12
0.87 0.97 1.07 1.17 1.27 1.37 Pooled SEM
2.71" 3.17b 3.62' 4.17d 4.52= 4.88f 0.13
135.2" 149.2b 163.3' 170.2^ 171.6d 169.6' d 2.4
311.7* 327.2b 338.5b 356.0' 356.0' 355.9' 3.3
2.307' 2.204b 2.074a 2.091' 2.075* 2.115* 0.015
16 to 20
0.61 0.68 0.75 0.82 0.89 0.96 Pooled SEM
3.28" 3.77b 4.31' 4.81d 5.25* 5.80f 0.15
161.8* 171.2* 182.0 b ' 183.7b' 190.9' 193.6' 2.5
538.1" 554.9*b 574.4* 587.0b 590.4b 604.3b 6.1
3.328b 3.241* 3.158*b 3.193* 3.082* 3.122* 0.023
Means within columns within age with no common superscript differ significantly (P < 0.05).
pattern between strains are most likely to influence the nutrient requirements in specific feeding periods (Leeson and Caston, 1991). In general, it is relatively difficult to relate the present data from the finisher phase to similar work done in poults of no more than 12 to 13 kg body weight at 18 wk of age (Moran et al, 1992; Waldroup et al, 1993; Sell et al, 1994). The present data support commercial recommendations around 3 g lysine/Mcal ME as advocated by Cuddy Farms (1990), BUT (1994), and Degussa (1993).
Carcass quality correlated to some degree with the growth rate observed during the finishing period. Birds on the highest lysine level of 0.96% had a considerably higher breast meat portion than was found in carcasses on the deficient and intermediate dietary lysine level. The same was true for carcass yield. One could speculate that turkeys may first respond with better growth when dietary lysine is raised, and would only show a breast meat response at dietary lysine levels allowing close-tomaximum growth. It is interesting to compare the breast
TABLE 5. Impact of dietary lysine 16 to 20 wk of age on carcass composition and meat quality in finishing turkeys Dietary lysine
Variable
0.61%
0.75%
0.96%
SEM
Body weight at slaughter, kg Dressing,1 % Carcass fat, % BW Inner organs (liver, heart, gizzard), % BW Carcass parts, % of carcass weight Breast2 Meat Skin Thighs2 Meat Skin Drumsticks Wings Meat quality (breast meat) Grill loss,3 % Tenderness4 Water content, % Protein content, % DM Fat content, % DM Ash content, % DM
17.81* 83.96*b 2.12 1.99*
18.21b 83.56* 2.50 1.78b
18.45' 84.46b 2.25 1.74b
0.05 0.11 0.08 0.02
33.46* 30.62* 2.85 16.62 13.75* 1.62 12.81 10.50
34.00*b 30.96*b 3.04 16.21 13.38*b 1.58 12.76 10.45
34.59b 31.79b 2.80 16.04 13.25b 1.57 12.94 10.45
0.19 0.19 0.09 0.12 0.08 0.07 0.09 0.08
32.41* 2.84 74.38 89.10* 6.87* 4.23
28.91b 2.64 73.75 91.52b 4.84b 4.25
29.64b 3.13 74.67 92.68b 4.03b 4.40
0.44 0.11 0.19 0.50 0.44 0.06
*"'Means within rows with no common superscript differ significantly (P < 0.05). deluding liver, heart, and gizzard. Excluding bones. 3 Grilled for 7.5 min to an internal meat temperature of 72 C; each sample wrapped in aluminum foil. 4 Using Warner-Bratzler-shear (G-R-Eleg Mfg. Co., New York, NY).
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a_f
LYSINE IN GROWING AND FINISHING TURKEYS
REFERENCES AEC, 1987. Tables AEC. 5th ed. A.E.C. Society de chimie organique et biologique, Commentry, France. Bohn, M., 1983. Untersuchungen zur Mastleistung, SchlachtkOrperzusammensetzung und zum Verfettungsgrad schwerer Puten-Hahne in Abhangigkeit von Herkunft, Futterzusammensetzung und Schlachtalter. Ph.D. thesis, University of Hohenheim, Germany. Brake, J., G. B. Havenstein, P. R. Ferket, D. V. Rives, and F. G. Giesbrecht, 1995. Relationship of sex, strain and body weight to carcass yield and offal production in turkeys. Poultry Science 74:161-168. British United Turkeys, 1994. Big 6 Performance Goals. Broughton, Chester, UK. Carlson, C. W., E. Guenthner, K. C. Schneider, L. P. Guild, D. Deethardt, and Y. A. Greichus, 1969. Effects of corn oil and lysine on growth, fatty acid composition and palatability of large broad white turkeys. Poultry Sci. 48: 1027-1033. Cuddy Farms, 1990. Recommendations for feeding commercial turkeys. S. Leeson, ed. Strathroy, ON, Canada. CVB (Centraal Veevoeder Bureau), 1994. Veevoedertabel. Lelystad, The Netherlands.
Degussa, 1993. Amino Acid Recommendations for Poultry. Degussa AG, Hanau, Germany. Gesellschaft der Ernahrungsphysiologie der Haustiere, 1973. Richtlinien zur Durchfuhrung von Bilanzversuchen mit Huhnern. Arch. Geflugelkd. 2:49-57 Hurwitz, S., J. Plavnik, I. Bengal, H. Talpaz, and J. Bartov, 1983. The amino acid requirements of growing turkeys. 2. Experimental validation of model—calculated requirements for sulfur amino acids and lysine. Poultry Sci. 62: 2387-2393. Hybrid Turkeys, 1990. Feeding Programs. Kitchener, ON, Canada. Institut National de la Recherche Agronomique, 1984. L'Alimentation des Animaux Monogastriques. Institut National de la Recherche Agronomique, Paris, France. Jensen, L. S., B. Manning, L. Falen, and J. McGinnis, 1976. Lysine needs of rapidly growing turkeys from 12-22 weeks of age. Poultry Sci. 55:1394-1400. Jeroch, H., 1995. Faustzahlen zur Geflugelfutterung. Pages 85-107 in: Jahrbuch fur die Geflugelfutterung 1995. J. Petersen, ed. Verlag Eugen Ulmer, Stuttgart, Germany. Kramer, S. L., and P. E. Waibel, 1979. Study of lysine requirement of growing turkeys at varying ambient temperatures. Poultry Sci. 58:1075. (Abstr.) Leeson, S., and L. J. Caston, 1991. Response of two strains of turkey hens to various protein and energy feeding programs. Poultry Sci. 70:1739-1747. Lilburn, M. S., and D. Emmerson, 1993. The influence of differences in dietary amino acids during the early growing period on growth and development of Nicholas and British United Turkey toms. Poultry Sci. 72:1722-1730. Llames, C, and J. Fontaine, 1994. Determination of amino acids in feeds: collaborative study. J. AOAC Int. 77:1362-1402. Moorgut Kartzfehn, 1993. Informationen zur Putenmast. Bosel, Germany. Moran, E. T., K. K. Krueger, and N. Acar, 1992. Response of male turkeys hatched from first-cycle and force-molted breeder hens to a regimen providing progressive feeds by weight and value of increased lysine prior marketing. Poultry Sci. 71:1891-1899. National Feed Ingredients Association, 1991. Supplemented amino acids (Methionine and lysine). Pages 71-72 in: NFIA Laboratory Methods Compendium. Vol. 3. National Feed Ingredients Association, West Des Moines, IA. National Research Council, 1984. Nutrient Requirements of Poultry. 8th rev. ed. National Academy Press, Washington, DC. National Research Council, 1994. Nutrient Requirements of Poultry. 9th rev. ed. National Academy Press, Washington, DC. Naumann, C, and R. Bassler, 1976. Verband Deutscher Landwirtschaftlicher Untersuchungs- und Forschungsanstalten. Methodenbuch Band III. Die chemische Untersuchung von Futtermitteln. 3. Erganzungslieferung 1993, VDLUFA-Verlag, Darmstadt, Germany. Nestor, K. E., W. L. Bacon, G. B. Havenstein, Y. M. Saif, and P. A. Renner, 1988. Carcass traits of turkeys from lines selected for increased growth rate or increased shank width. Poultry Sci. 67:1660-1667. Nixey, C, 1989. Nutritional responses of growing Turkeys. Pages 183-189 in: Recent Advances in Turkey Science. C. Nixey and T. C. Grey, ed. Butterworth, London, UK. Noll, S. L., and P. E. Waibel, 1989. Lysine requirements of growing turkeys in various temperature environments. Poultry Sci. 68:781-794.
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meat yield data obtained in this study to a recent survey by Brake et al. (1995) of U.S. commercial turkeys. Carcasses from birds of u p to 17.6 kg body weight were cut up and regression equations were estimated to calculate the weight of various carcass parts depending on live body weight. Using their regressions for the weight of the P. major plus P. minor, one could expect about 4,300 g of breast meat in BUT toms of 18.5 kg. The actual breast meat yield in the present group receiving 0.96% dietary lysine was 4,851 g, which might, disregarding possible differences in cutting procedure, indicate the potential of the BUT stock to express even higher yield than currently seen under field conditions. However, because this study was limited to three treatment groups and the relatively small number of 20 carcasses per diet, the present data on yield and carcass composition need to be interpreted carefully. Interestingly, an effect of dietary lysine on carcass fatness was not detected, which may be the net effect of increased fat with higher body weight and less fat with more adequate lysine in the diet. The results of meat quality determination showed that with increasing dietary lysine the fat content in the breast meat decreased, although there was virtually no difference in total carcass fat content. With decreasing fat content, breast meat protein increased proportionately. The higher fat content in the breast meat of birds fed the unsupplemented diet may have been the reason for the higher grill loss in breast meat samples obtained from those carcasses. Meat tenderness as measured by shear force did not show any consistent change along with the differences observed in protein and fat content of the meat. Thus there is probably no negative impact of improved leanness on meat quality for the consumer.
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