- Email: [email protected]
The Ability of the Broiler Chicken to Compensate for Early Growth Depression
262
K. K. HALE, JR., W. J. STADELMAN AND V. D. BRAMBLETT
of food flavor. Food Technol. 22: 383-388. Powers, J. J., and E. S. Keith, 1968. Stepwise discriminant analysis of gas chromatographic data as an aid in classifying the flavor quality of foods. J. Food Sci. 33: 207-213. Rao, C. R., 19S2. Tests of significance in multivariate analysis. In Advanced Statistical Methods in Biometric Research. John Wiley and Sons, Inc., New York.
Scheffe, H., 1952. An analysis of variance for paired comparisons. J. Am. Statistical Assoc. 7: 381-400. Steel, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw-Hill Book Company, Inc., New York. Stevens, A., 1970. Chilling equipment must go, Hillcrest's Stevens insists. Broiler Industry, 33(3): S3.
J. W. DEATON, 1 F. N. REECE, 2 L. F. KUBENA, 1 B. D. LOTT 1 AND J. D. MAY 1 United States Department of Agriculture, A.R.S., State College, Mississippi 39762 (Received for publication May 1, 1972)
ABSTRACT Previous work at this laboratory demonstrated that broiler chicks could compensate by market age from early growth depression when reduced brooding temperature was the deterrent. Lott (1971) demonstrated diets which depressed broiler body weight at 4 weeks of age. The major diet differences were dietary energy levels. In an attempt to determine if the compensatory ability phenomenon could be utilized in broiler diet formulations for possible economic gain, 3 trials utilizing a total of 2,736 commercial broiler chickens were conducted. Results obtained showed that birds fed a diet containing 3141 kcal. of M.E.Ag- had a 4% reduction in body weight at 4 weeks of age, as compared to birds fed a diet containing 3306 kcal. of M.E./kg. By 8 weeks of age the males were able to compensate for the 4% reduction in 4-week body weight when fed a high-energy diet containing 3372 kcal. of M.E.Ag- Females could compensate for the 4% reduction in 4-week weight by 8 weeks of age when fed diets containing either 3207 or 3372 kcal. of M.E./kg. The percentage ether extract of the carcass at market age increased, however, for the groups demonstrating compensatory weight gain ability. Feed required per unit of gain increased as energy content of diet combinations decreased. POULTRY SCIENCE 52:
INTRODUCTION
P
REVIOUS work at this laboratory (Reece and Deaton, 1968) demonstrated that when body weights for broiler chicks brooded with reduced heat were not more than 13% lower at 3 weeks than those conventionally brooded, the bodyweight differences were eliminated by 8 weeks of age. Between 3 and 8 weeks, all birds were reared in one group. Lott 1 Animal Science Research Division, Poultry Research Branch, South Central Poultry Research Laboratory, State College, Mississippi. 2 Agricultural Engineering Research Division, Farm Electrification Research Branch, South Central Poultry Research Laboratory, State College, Mississippi.
262-265,
1973
(1971) demonstrated diets which depressed broiler body weight at 4 weeks of age. The major diet differences were dietary energy levels. In an attempt to determine if the compensatory ability phenomenon could be utilized in broiler diet formulations for possible economic advantage, the following study was conducted. EXPERIMENTAL PROCEDURE
Three trials utilizing a total of 2,736 commercial broiler chickens were conducted. For each trial, 12 1.51- by 3.7-meter pens were used with 38 male and 38 female broiler chicks placed per pen. The
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
The Ability of the Broiler Chicken to Compensate for Early Growth Depression
263
EARLY GROWTH DEPRESSION
TABLE 1.—Composition and calculated analysis of the starter diets {1-28 days) Diets—Kcal. of M.E./kg. 3306
(%) Corn, yellow Alfalfa meal, 17% protein Soybean meal, 50% protein Fish meal, peruvian Fat, animal Dical phos., 26.0% Ca18.5% P Limestone Salt Coccidiostat (Zoalene) DL-Methionine, 98% Vitamin-Mineral-Premix* Total % Calculated analysis: Energy level, kcal./kg. Protein, % Calcium, % Avail. Phosphorus, % Arginine, % Lysine, % Methionine, % Cystine, % Tryptophan, %
3141
(%)
57.18 1.58 22.52 10.00 6.77
66.32 .54 19.80 10.00 1.56
.62 .71 .25 .05 .07 .25
.46 .73 .25 .05 .04 .25
100.00
100.00
3306 22.96 .90 .48 1.52 1.36 .59 .37 .31
3141 22.22 .86 .45 1.46 1.29 .55 36 .29
* The vitamin-mineral-premix contained the following per kilogram of premix: Vitamin A palmitate, U.S.P. units, 2,204,634; Vitamin D 3 , I.C.U., 661,390; Vitamin E, I.U., 441; Riboflavin, mgs., 1764; Niacin, mgs., 11,023; D-pantothenic acid, mgs., 3,527; Folic acid, mgs., 55; Vitamin B12, mgs., 3.5; Choline chloride, mgs., 198,417; Ethoxyquin, gms., 35; Menadione sodium bisulfite, mgs., 556; Manganese, gms., 26.5; Zinc, gms., 17.6; Iodine, gms., 0.5; Ferrous sulfate, gms., 8.0; Cooper, gms., 0.8; Cobalt, gms., 0.08.
Table 2.—Composition and calculated analysis of the finisher diets (29-56 days) Diets—Kcal. of M.E./kg. 3372
(%)
60.15 Corn, yellow 2.54 Alfalfa meal, 17% protein Soybean meal, 50% protien 17.67 10.00 Fish meal, Peruvian Rice bran, solv. ext. — 7.68 Fat, animal Dical Phos., 26.0% Ca18.5% P .71 Limestone .70 Salt .25 Coccidiostat (Zoalene) .05 Vitamin-Mineral-Premix* .25 Total % Calculated analysis: Energy level, kcal./kg. Protein, % Calcium, % Avail. Phosphorus, % Arginine, % Lysine, % Methionine, % Cystine, % Tryptophan, %
3207
(%)
69.26 1.16 15.31 10.00
3042
(%)
2.43
64.86 1.44 13.79 9.05 8.13 1.00
.57 .72 .25 .05 .25
.42 .76 .25 .05 .25
100.00
100.00
100.00
3372 20.96 .92 .49 1.36 1.22 .49 .34 .28
3207 20.34 .87 .47 1.31 1.16 .49 .33 .26
3042 19.69 .83 .44 1.27 1.10 .46 .32 .26
—
* The vitamin-mineral-premix contained the following per kilogram of premix: Vitamin A palmitate, U.S.P. units, 2,204,634; Vitamin D 3 , I.C.U., 661,390; Vitamin E, I.U., 441; Riboflavin, mgs. 1764; Niacin, mgs. 11,023; D-pantothenic acid, mgs., 3,527; Folic acid, mgs., 55; Vitamin B12, mgs., 3.5; Choline chloride, mgs., 198,417; Ethoxyquin, gms., 35; Menadione sodium bisulfite, mgs., 556; Manganese, gms., 26.5; Zinc, gms., 17.6; Iodine, gms., 0.5; Ferrous sulfate, gms., 8.0; Copper, gms., 0.8; Cobalt, gms., 0.08.
of approximately 50%. For the first week, the birds were brooded at 32.2°C, the second week at 29.4°C, the third week at 26.7°C. and the fourth week at 23.9°C. The feeder and waterer space consisted of two 38.1-cm.-diameter tube feeders and 244 linear cm. of waterer space for each 76bird group. All chicks were vaccinated at 10 days of age with B 1 type Newcastle and Massachusetts and Connecticut type bronchitis vaccines. Body fat as expressed by ether extract was measured using the Soxhlet's apparatus. Duplicate samples of four birds of each
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
general experimental design consisted of 6 dietary treatment combinations with 2 pens per dietary treatment for each trial. Two starter diets with 3306 and 3141 kcal. of metabolizable energy (M.E.)/kg. were fed for the first 4 weeks. Finisher diets containing 3372, 3207 and 3042 kcal. of M.E./kg. were fed from 4 to 8 weeks of age after each of the starter diets. The composition and calculated analysis of the five diets used are given in Tables 1 and 2. From 5 to 8 weeks of age, birds for all trials were reared under a constant temperature of 21.1°C. with a relative humidity
264
DEATON, REECE, KUBENA, LOTT AND MAY
TABLE 3.—Effect of diet on 4-week body weig, an Diet (Kcal. of M.E./kg.) 3306 3141
Body wt. (gms.) Male
Female
Body wt. diff. (%) Male
Female
Feed per unit gain
671a* 644b
588a 562b
-4.0
-4.4
1.60a 1.67b
* Within each column, differing letters denote significance at the .05 level of probability.
RESULTS AND DISCUSSION
Rearing broiler chicks from 1 day to 4 weeks of age on a diet containing 3141 kcal. of M.E./kg. as compared to chicks reared on a diet containing 3306 kcal. of M.E./kg. resulted in approximately a 4% reduction in body weight for both sexes (Table 3). Lott (1971) obtained a 7% reduction in body weight at 30 days of age using a 2976 kcal. of M.E./kg. diet as compared to chicks fed a diet containing 3306 kcal. of M.E./kg. The ability of commercial broilers to compensate for early growth depression caused by diet is demonstrated in data preTABLE 4.—Effect
of diet on body
Body wt. (gms.) Diet 1 Starter/Finisher (Kcal. of M.E./kg.) Male Female 3306/3372 3306/3207 3306/3042 3141/3372 3141/3207 3141/3042
2
1806ab 1820a 1779abc 1807ab 1758bc 1747c
1468ab 1475a 1470ab 1472ab 1451ab 1429b
', feed utilization, mortality and ether extract Feed per Unit gain 2.09a 2.12ab 2.19cd 2.10ab 2.15bc 2.22d
Mortality
Ether extract (%)
No.
%
Male
Female
3a 9a 3a 8a 7a 5a
0.7 2.0 0.7 1.8 1.5 1.1
11.27a 12.33bc 10.57d 12.01c 12.51bc 12.82b
12.47bc 12.19cd 11.37d 13.30a 13.16ab 11.72cd
1 Starter diets (Table 1) were fed for the first 28 days of age. Finisher diets (Table 2) were fed after 28 days of age. 2 Within each column, differing letters denote significance at the .05 level of probability.
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
sex, 56 to 63 days of age, were randomly selected. For females, body fat was determined for each trial. For males, body fat was determined for two of the three trials. An analysis of variance described by Snedecor and Cochran (1956) was used with Duncan's (1955) multiple range test used to separate significant treatment means.
sented in Table 4. Both males and females receiving the 3372 kcal. of M.E./kg. diet for the last 4 weeks, but receiving differing diets to 4 weeks of age, weighed almost the same for each sex at 8 weeks of age (Table 4). The ability to compensate completely for early weight loss occurred only, however, when a high-energy diet was fed the last 4 weeks. Males receiving the 3141 and 3207 kcal./kg. diet combination weighed significantly less at 8 weeks than males receiving the 3306 and 3207 kcal./kg. diet combination (Table 4). Although not statistically significant, the same trend existed for females receiving the 3141 and 3207 kcal./kg. diet combination to weigh less at 8 weeks than females receiving the 3306 and 3207 kcal./kg. diet combination. Also, both males and females receiving the 3141 and 3042 kcal./kg. diet combination were not able to compensate completely for early weight loss when compared to birds receiving the 3306 and 3042 kcal./kg. diet combination (Table 4). The amount of feed required per unit of gain increased as dietary energy level decreased (Table 4). Mortality was not significantly affected by dietary treatment. Since excess carcass fat is undesirable, total-body ether extract was measured to determine if the compensated weight gain might be only an addition of fat. Results show that when birds were reared on the
EARLY GROWTH DEPRESSION
diet. In fact, Kubena et al. (1972) found that in most cases, there was a decrease in abdominal fat deposition at market age when the low-energy starter diet was fed and compared to birds reared on the highenergy starter diet. REFERENCES Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Kubena, L. F., T. C. Chen, J. W. Deaton, F. N. Reece and J. D. May, 1972. The effect of dietary energy level, age and sex on quantity of abdominal fat in broilers. Personal communications. Lott, B. D., Sr., 1971. The effect of dietary energy levels and environmental temperatures on broiler performance. A thesis submitted to the faculty of Mississippi State University, Mississippi State University Library, State College, Mississippi. Reece, F. N., and J. W. Deaton, 1968. Implications of reduced heat during brooding of broilers. Proc. Assoc. Sou. Agric. Workers, 65: 218-219. Snedecor, G. W., and W. G. Cochran, 1956. Statistical Methods. The Iowa State College Press, Ames, Iowa.
NEWS AND NOTES (Continued from page 252) tritionist at Master Feeds, Maple Leaf Mills Limited, Toronto, Ontario. He will be involved in research and ration formulation. He was born in Dockum, the Netherlands, and received B.Sc. and M.Sc. degrees in Agriculture at Macdonald College, McGill University, in 1967 and 1969, respectively, and a Ph.D. in animal nutrition at the University of Illinois in 1972. COBB NOTES Cobb International has appointed David J. Kuleisus as Managing Director of the Mideast Division with offices in Athens, Greece. He will be responsible for extensive marketing and production operations in Greece, Turkey, Iran, the Mideast, and the countries of North Africa. He has been elected to the Borad of Directors of Cobb Middle East, S.A.L., in Lebanon. Cobb International, Inc., has appointed Danilo D. Correz to Regional Manager, South East Asian countries. A graduate of the University of the
Philippines with a degree in agriculture, he has worked in various poultry management capacities for 18 years. Correz became associated with Cobb International three years ago. AMERICAN POULTRY HISTORICAL SOCIETY Poultry history will continue to live if it is not lost. Financially that is. The poultry industry has a notable history of which to be proud. Much of this history can be lost if it is not recorded. The only organization whose principal interest is the preservation of this challenging history is the American Poultry Historical Society (A.P.H.S.). The purpose of the A.P.H.S. is to find, collect and preserve records, pictures, data, materials and objects connected with the development of the Poultry Industry, and to make available its great history to this and future generations, and to honor or recognize persons for outstanding achievement or leadership. The major source of
(Continued on page 295)
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
same finishing diets, but started on differing diets for the first 4 weeks, a higher ether extract was noted for the compensated weight gain group (Table 4). For example, birds receiving the 3141/3372 kcal. /kg. starter-finisher diet weighed about the same as those receiving the 3306/3372 kcal./kg. diet. The ether extract, however, was significantly higher for both males and females receiving the 3141/3372 kcal./kg. diet. The site of additional fat deposition for birds that demonstrate compensatory ability for body weight gain remains to be determined. Kubena et al. (1972) used the diets described in Tables 1 and 2 in studies designed to determine diet effect on amount of abdominal fat in broilers. Their results showed that the amount of abdominal fat did not increase when the low-energy diet was fed the first 4 weeks and compared to birds reared on the high-energy diet, then reared after 4 weeks of age on a common
265
K. K. HALE, JR., W. J. STADELMAN AND V. D. BRAMBLETT
of food flavor. Food Technol. 22: 383-388. Powers, J. J., and E. S. Keith, 1968. Stepwise discriminant analysis of gas chromatographic data as an aid in classifying the flavor quality of foods. J. Food Sci. 33: 207-213. Rao, C. R., 19S2. Tests of significance in multivariate analysis. In Advanced Statistical Methods in Biometric Research. John Wiley and Sons, Inc., New York.
Scheffe, H., 1952. An analysis of variance for paired comparisons. J. Am. Statistical Assoc. 7: 381-400. Steel, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw-Hill Book Company, Inc., New York. Stevens, A., 1970. Chilling equipment must go, Hillcrest's Stevens insists. Broiler Industry, 33(3): S3.
J. W. DEATON, 1 F. N. REECE, 2 L. F. KUBENA, 1 B. D. LOTT 1 AND J. D. MAY 1 United States Department of Agriculture, A.R.S., State College, Mississippi 39762 (Received for publication May 1, 1972)
ABSTRACT Previous work at this laboratory demonstrated that broiler chicks could compensate by market age from early growth depression when reduced brooding temperature was the deterrent. Lott (1971) demonstrated diets which depressed broiler body weight at 4 weeks of age. The major diet differences were dietary energy levels. In an attempt to determine if the compensatory ability phenomenon could be utilized in broiler diet formulations for possible economic gain, 3 trials utilizing a total of 2,736 commercial broiler chickens were conducted. Results obtained showed that birds fed a diet containing 3141 kcal. of M.E.Ag- had a 4% reduction in body weight at 4 weeks of age, as compared to birds fed a diet containing 3306 kcal. of M.E./kg. By 8 weeks of age the males were able to compensate for the 4% reduction in 4-week body weight when fed a high-energy diet containing 3372 kcal. of M.E.Ag- Females could compensate for the 4% reduction in 4-week weight by 8 weeks of age when fed diets containing either 3207 or 3372 kcal. of M.E./kg. The percentage ether extract of the carcass at market age increased, however, for the groups demonstrating compensatory weight gain ability. Feed required per unit of gain increased as energy content of diet combinations decreased. POULTRY SCIENCE 52:
INTRODUCTION
P
REVIOUS work at this laboratory (Reece and Deaton, 1968) demonstrated that when body weights for broiler chicks brooded with reduced heat were not more than 13% lower at 3 weeks than those conventionally brooded, the bodyweight differences were eliminated by 8 weeks of age. Between 3 and 8 weeks, all birds were reared in one group. Lott 1 Animal Science Research Division, Poultry Research Branch, South Central Poultry Research Laboratory, State College, Mississippi. 2 Agricultural Engineering Research Division, Farm Electrification Research Branch, South Central Poultry Research Laboratory, State College, Mississippi.
262-265,
1973
(1971) demonstrated diets which depressed broiler body weight at 4 weeks of age. The major diet differences were dietary energy levels. In an attempt to determine if the compensatory ability phenomenon could be utilized in broiler diet formulations for possible economic advantage, the following study was conducted. EXPERIMENTAL PROCEDURE
Three trials utilizing a total of 2,736 commercial broiler chickens were conducted. For each trial, 12 1.51- by 3.7-meter pens were used with 38 male and 38 female broiler chicks placed per pen. The
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
The Ability of the Broiler Chicken to Compensate for Early Growth Depression
263
EARLY GROWTH DEPRESSION
TABLE 1.—Composition and calculated analysis of the starter diets {1-28 days) Diets—Kcal. of M.E./kg. 3306
(%) Corn, yellow Alfalfa meal, 17% protein Soybean meal, 50% protein Fish meal, peruvian Fat, animal Dical phos., 26.0% Ca18.5% P Limestone Salt Coccidiostat (Zoalene) DL-Methionine, 98% Vitamin-Mineral-Premix* Total % Calculated analysis: Energy level, kcal./kg. Protein, % Calcium, % Avail. Phosphorus, % Arginine, % Lysine, % Methionine, % Cystine, % Tryptophan, %
3141
(%)
57.18 1.58 22.52 10.00 6.77
66.32 .54 19.80 10.00 1.56
.62 .71 .25 .05 .07 .25
.46 .73 .25 .05 .04 .25
100.00
100.00
3306 22.96 .90 .48 1.52 1.36 .59 .37 .31
3141 22.22 .86 .45 1.46 1.29 .55 36 .29
* The vitamin-mineral-premix contained the following per kilogram of premix: Vitamin A palmitate, U.S.P. units, 2,204,634; Vitamin D 3 , I.C.U., 661,390; Vitamin E, I.U., 441; Riboflavin, mgs., 1764; Niacin, mgs., 11,023; D-pantothenic acid, mgs., 3,527; Folic acid, mgs., 55; Vitamin B12, mgs., 3.5; Choline chloride, mgs., 198,417; Ethoxyquin, gms., 35; Menadione sodium bisulfite, mgs., 556; Manganese, gms., 26.5; Zinc, gms., 17.6; Iodine, gms., 0.5; Ferrous sulfate, gms., 8.0; Cooper, gms., 0.8; Cobalt, gms., 0.08.
Table 2.—Composition and calculated analysis of the finisher diets (29-56 days) Diets—Kcal. of M.E./kg. 3372
(%)
60.15 Corn, yellow 2.54 Alfalfa meal, 17% protein Soybean meal, 50% protien 17.67 10.00 Fish meal, Peruvian Rice bran, solv. ext. — 7.68 Fat, animal Dical Phos., 26.0% Ca18.5% P .71 Limestone .70 Salt .25 Coccidiostat (Zoalene) .05 Vitamin-Mineral-Premix* .25 Total % Calculated analysis: Energy level, kcal./kg. Protein, % Calcium, % Avail. Phosphorus, % Arginine, % Lysine, % Methionine, % Cystine, % Tryptophan, %
3207
(%)
69.26 1.16 15.31 10.00
3042
(%)
2.43
64.86 1.44 13.79 9.05 8.13 1.00
.57 .72 .25 .05 .25
.42 .76 .25 .05 .25
100.00
100.00
100.00
3372 20.96 .92 .49 1.36 1.22 .49 .34 .28
3207 20.34 .87 .47 1.31 1.16 .49 .33 .26
3042 19.69 .83 .44 1.27 1.10 .46 .32 .26
—
* The vitamin-mineral-premix contained the following per kilogram of premix: Vitamin A palmitate, U.S.P. units, 2,204,634; Vitamin D 3 , I.C.U., 661,390; Vitamin E, I.U., 441; Riboflavin, mgs. 1764; Niacin, mgs. 11,023; D-pantothenic acid, mgs., 3,527; Folic acid, mgs., 55; Vitamin B12, mgs., 3.5; Choline chloride, mgs., 198,417; Ethoxyquin, gms., 35; Menadione sodium bisulfite, mgs., 556; Manganese, gms., 26.5; Zinc, gms., 17.6; Iodine, gms., 0.5; Ferrous sulfate, gms., 8.0; Copper, gms., 0.8; Cobalt, gms., 0.08.
of approximately 50%. For the first week, the birds were brooded at 32.2°C, the second week at 29.4°C, the third week at 26.7°C. and the fourth week at 23.9°C. The feeder and waterer space consisted of two 38.1-cm.-diameter tube feeders and 244 linear cm. of waterer space for each 76bird group. All chicks were vaccinated at 10 days of age with B 1 type Newcastle and Massachusetts and Connecticut type bronchitis vaccines. Body fat as expressed by ether extract was measured using the Soxhlet's apparatus. Duplicate samples of four birds of each
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
general experimental design consisted of 6 dietary treatment combinations with 2 pens per dietary treatment for each trial. Two starter diets with 3306 and 3141 kcal. of metabolizable energy (M.E.)/kg. were fed for the first 4 weeks. Finisher diets containing 3372, 3207 and 3042 kcal. of M.E./kg. were fed from 4 to 8 weeks of age after each of the starter diets. The composition and calculated analysis of the five diets used are given in Tables 1 and 2. From 5 to 8 weeks of age, birds for all trials were reared under a constant temperature of 21.1°C. with a relative humidity
264
DEATON, REECE, KUBENA, LOTT AND MAY
TABLE 3.—Effect of diet on 4-week body weig, an Diet (Kcal. of M.E./kg.) 3306 3141
Body wt. (gms.) Male
Female
Body wt. diff. (%) Male
Female
Feed per unit gain
671a* 644b
588a 562b
-4.0
-4.4
1.60a 1.67b
* Within each column, differing letters denote significance at the .05 level of probability.
RESULTS AND DISCUSSION
Rearing broiler chicks from 1 day to 4 weeks of age on a diet containing 3141 kcal. of M.E./kg. as compared to chicks reared on a diet containing 3306 kcal. of M.E./kg. resulted in approximately a 4% reduction in body weight for both sexes (Table 3). Lott (1971) obtained a 7% reduction in body weight at 30 days of age using a 2976 kcal. of M.E./kg. diet as compared to chicks fed a diet containing 3306 kcal. of M.E./kg. The ability of commercial broilers to compensate for early growth depression caused by diet is demonstrated in data preTABLE 4.—Effect
of diet on body
Body wt. (gms.) Diet 1 Starter/Finisher (Kcal. of M.E./kg.) Male Female 3306/3372 3306/3207 3306/3042 3141/3372 3141/3207 3141/3042
2
1806ab 1820a 1779abc 1807ab 1758bc 1747c
1468ab 1475a 1470ab 1472ab 1451ab 1429b
', feed utilization, mortality and ether extract Feed per Unit gain 2.09a 2.12ab 2.19cd 2.10ab 2.15bc 2.22d
Mortality
Ether extract (%)
No.
%
Male
Female
3a 9a 3a 8a 7a 5a
0.7 2.0 0.7 1.8 1.5 1.1
11.27a 12.33bc 10.57d 12.01c 12.51bc 12.82b
12.47bc 12.19cd 11.37d 13.30a 13.16ab 11.72cd
1 Starter diets (Table 1) were fed for the first 28 days of age. Finisher diets (Table 2) were fed after 28 days of age. 2 Within each column, differing letters denote significance at the .05 level of probability.
Downloaded from http://ps.oxfordjournals.org/ at Simon Fraser University on June 6, 2015
sex, 56 to 63 days of age, were randomly selected. For females, body fat was determined for each trial. For males, body fat was determined for two of the three trials. An analysis of variance described by Snedecor and Cochran (1956) was used with Duncan's (1955) multiple range test used to separate significant treatment means.
sented in Table 4. Both males and females receiving the 3372 kcal. of M.E./kg. diet for the last 4 weeks, but receiving differing diets to 4 weeks of age, weighed almost the same for each sex at 8 weeks of age (Table 4). The ability to compensate completely for early weight loss occurred only, however, when a high-energy diet was fed the last 4 weeks. Males receiving the 3141 and 3207 kcal./kg. diet combination weighed significantly less at 8 weeks than males receiving the 3306 and 3207 kcal./kg. diet combination (Table 4). Although not statistically significant, the same trend existed for females receiving the 3141 and 3207 kcal./kg. diet combination to weigh less at 8 weeks than females receiving the 3306 and 3207 kcal./kg. diet combination. Also, both males and females receiving the 3141 and 3042 kcal./kg. diet combination were not able to compensate completely for early weight loss when compared to birds receiving the 3306 and 3042 kcal./kg. diet combination (Table 4). The amount of feed required per unit of gain increased as dietary energy level decreased (Table 4). Mortality was not significantly affected by dietary treatment. Since excess carcass fat is undesirable, total-body ether extract was measured to determine if the compensated weight gain might be only an addition of fat. Results show that when birds were reared on the
EARLY GROWTH DEPRESSION
diet. In fact, Kubena et al. (1972) found that in most cases, there was a decrease in abdominal fat deposition at market age when the low-energy starter diet was fed and compared to birds reared on the highenergy starter diet. REFERENCES Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Kubena, L. F., T. C. Chen, J. W. Deaton, F. N. Reece and J. D. May, 1972. The effect of dietary energy level, age and sex on quantity of abdominal fat in broilers. Personal communications. Lott, B. D., Sr., 1971. The effect of dietary energy levels and environmental temperatures on broiler performance. A thesis submitted to the faculty of Mississippi State University, Mississippi State University Library, State College, Mississippi. Reece, F. N., and J. W. Deaton, 1968. Implications of reduced heat during brooding of broilers. Proc. Assoc. Sou. Agric. Workers, 65: 218-219. Snedecor, G. W., and W. G. Cochran, 1956. Statistical Methods. The Iowa State College Press, Ames, Iowa.
NEWS AND NOTES (Continued from page 252) tritionist at Master Feeds, Maple Leaf Mills Limited, Toronto, Ontario. He will be involved in research and ration formulation. He was born in Dockum, the Netherlands, and received B.Sc. and M.Sc. degrees in Agriculture at Macdonald College, McGill University, in 1967 and 1969, respectively, and a Ph.D. in animal nutrition at the University of Illinois in 1972. COBB NOTES Cobb International has appointed David J. Kuleisus as Managing Director of the Mideast Division with offices in Athens, Greece. He will be responsible for extensive marketing and production operations in Greece, Turkey, Iran, the Mideast, and the countries of North Africa. He has been elected to the Borad of Directors of Cobb Middle East, S.A.L., in Lebanon. Cobb International, Inc., has appointed Danilo D. Correz to Regional Manager, South East Asian countries. A graduate of the University of the
Philippines with a degree in agriculture, he has worked in various poultry management capacities for 18 years. Correz became associated with Cobb International three years ago. AMERICAN POULTRY HISTORICAL SOCIETY Poultry history will continue to live if it is not lost. Financially that is. The poultry industry has a notable history of which to be proud. Much of this history can be lost if it is not recorded. The only organization whose principal interest is the preservation of this challenging history is the American Poultry Historical Society (A.P.H.S.). The purpose of the A.P.H.S. is to find, collect and preserve records, pictures, data, materials and objects connected with the development of the Poultry Industry, and to make available its great history to this and future generations, and to honor or recognize persons for outstanding achievement or leadership. The major source of
(Continued on page 295)
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same finishing diets, but started on differing diets for the first 4 weeks, a higher ether extract was noted for the compensated weight gain group (Table 4). For example, birds receiving the 3141/3372 kcal. /kg. starter-finisher diet weighed about the same as those receiving the 3306/3372 kcal./kg. diet. The ether extract, however, was significantly higher for both males and females receiving the 3141/3372 kcal./kg. diet. The site of additional fat deposition for birds that demonstrate compensatory ability for body weight gain remains to be determined. Kubena et al. (1972) used the diets described in Tables 1 and 2 in studies designed to determine diet effect on amount of abdominal fat in broilers. Their results showed that the amount of abdominal fat did not increase when the low-energy diet was fed the first 4 weeks and compared to birds reared on the high-energy diet, then reared after 4 weeks of age on a common
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