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The Effect of Steam Pelleting on the True Metabolizable Energy Values of Poultry Diets1
The Effect of Steam Pelleting on the True Metabolizable Energy Values of Poultry Diets1 I. R. SIBBALD Animal Research Institute, Agriculture Canada, Central Experimental Farm, Ottawa, Ontario K1A 0C6 (Received for publication April 12, 1977)
INTRODUCTION There is evidence that the apparent metabolizable energy (A.M.E.) values of some feedingstuffs are increased by steam pelleting (Reddy et al., 1962). However, the effect of pelleting is not consistent (Blakely et al., 1963; Sell and Thompson, 1965). It appears that steam pelleting has the most marked effects when the feedingstuff contains either high levels of fibre or heat labile growth depressants (Cave et al., 1965; Bayley et al., 1968; Summers et al, 1968; Summers, 1975). There is no published information describing the effect of steam pelleting on the T.M.E. values of feedingstuffs. Sibbald (1976a) compared the T.M.E. of whole and cold pelleted grains but the data are not directly relevant because the pelleting process caused the grain kernels to be broken. The effects observed may have been caused by disruption of the kernels rather than by the production of pellets. The purpose of the present work was to measure the effects of steam pelleting on the T.M.E. values of poultry diets. MATERIALS AND METHODS Experiment 1. Seven diets, prepared as mash and steam pellets, were each assayed four times for T.M.E. by the method of Sibbald (1976b). Additional measurements were made on reground pellets. The diets included corn:wheat: soybean broiler starter and finisher diets (1,2),
1
Contribution No. 698, Animal Research Institute.
a corn:soybean chick starter (3), diets similar to 3 but supplemented with 20 and 30% of rapeseed meal (4,5), diet 5 supplemented with 1 p.p.m. of selenium (6), and diet 5 supplemented with 0.25% of potassium carbonate (7). A t-test was used to determine if the T.M.E. values of the mash and pelleted forms of a diet were significantly different. Experiment 2. Three diets, prepared as mash and steam pellets, were each assayed seven times for T.M.E. while additional measurements were made on reground pellets. The diets, which were prepared in a commercial mill, included a breeding hen diet (1), a turkey broiler finisher (2), and a chicken broiler finisher (3). RESULTS The data obtained are summarized as means in Tables 1 and 2. The differences between the mash and pelleted forms of the diets were small and exhibited no consistent trend. The absence of significant (P<0.05) differences was confirmed by the series of t-tests. The reground pellets of diet 5 (Table 1) appeared to contain more T.M.E. than did the intact pellets (3.96 vs. 3.72 kcal./g.). However, the mean for the reground pellets was based on only two determinations and a t-test showed that the difference was not significant. DISCUSSION Practical diets of the types evaluated in experiment 2 are expected to be low in fibre and essentially free of heat labile growth
1686
Downloaded from http://ps.oxfordjournals.org/ at Gazi Universitesi on May 1, 2015
ABSTRACT Two experiments were made to measure the effects of steam pelleting on the true metabolizable energy (T.M.E.) values of ten poultry diets. None of the differences between the T.M.E. values of the diets before and after pelleting was significant (P>0.05). A small number of observations demonstrated that the T.M.E. values of reground and intact pellets were similar. It was concluded that, under the conditions of the two experiments, steam pelleting did not change the T.M.E. values of the diets. Poultry Science 56:1686-1688, 1977
RESEARCH NOTE
1687
TABLE 1.—The mean T.M.E. values of seven diets fed as mash, steam pellets and reground pellets
Diet
Mash1
Pellets'
Reground pellets2
3.64 3.95 3.66 3.65 3.74 3.73 3.67
3.65 3.92 3.63 -3.73 3.72 3.74 3.66
3.65 3.80 3.58 3.58 3.96 3.68 3.70
± 0.05 + 0.01 ±0.06 ±0.02 ± 0.04 ± 0.02 ± 0.05
±0.02 + 0.04 ± 0.07 ± 0.05 ± 0.03 ± 0.06 ±0.02
1
Data are means, with standard errors, of 4 determinations expressed as kcal./g. of dry matter.
2
Data are means of the number of determinations shown in brackets.
±0.04 (3) ± 0.09 (3) ±0.12 (2) ± 0.02 (2) ± 0.03 (2) ± 0.03 (3) ± 0.08 (3)
Diet
Mash1
Pellets1
Reground pellets2
3.38 ±0.03 3.88 ± 0.03 3.76 ± 0.05
3.40 ±0.03 3.81 ± 0.02 3.73 ± 0.02
3.47 ± 0.01 (3) 3.78 + 0.02(3) 3.73 ± 0.06 (4)
1
Data are means, with standard errors, of 7 determinations expressed as kcal./g. of dry matter.
2
Data are means of the number of determinations shown in brackets.
depressants; c o n s e q u e n t l y , it is n o t surprising t h a t their T.M.E. values were n o t improved b y steam pelleting. However, diets 4 t o 7 of e x p e r i m e n t 1 c o n t a i n e d from 2 0 t o 30% of rapeseed meal which is a r a t h e r fibrous feedingstuff b u t again steam pelleting was w i t h o u t effect. In a review of t h e effects of s t e a m pelleting Calet ( 1 9 6 5 ) presents evidence t h a t birds t e n d t o eat m o r e pellets t h a n mash. This difference in voluntary feed intake, if large, could have a p r o f o u n d effect u p o n t h e A.M.E. value of a diet (Sibbald, 1 9 7 5 ) . It seems possible t h a t s o m e of t h e differences in energy availability a t t r i b u t e d t o t h e steam pelleting process m a y reflect differences in feed c o n s u m p t i o n . It is interesting t o n o t e t h a t diets 5 and 6 (Table 1) have similar T.M.E. values while differing in selenium c o n t e n t . C o a t e s ( 1 9 7 3 ) observed t h a t naturally occurring selenium affected t h e A.M.E. values of w h e a t s . T h e present work was n o t performed t o investigate t h e effects of selenium; t h e d a t a o b t a i n e d c a n n o t be considered conclusive b u t the possible contradiction suggests a line for f u t u r e work.
ACKNOWLEDGEMENTS T h e a u t h o r is indebted t o Dr. J. D. Summers, University of Guelph for providing t h e diets evaluated in e x p e r i m e n t 1 and t o Dr. H. Likuski, Canada Packers, T o r o n t o , for t h e diets used in e x p e r i m e n t 2. T h a n k s are e x t e n d e d t o Mrs. S. T o b i n for her able technical assistance.
REFERENCES Bayley, H. S., J. D. Summers and S. J. Slinger, 1968. The effect of steam pelleting feed ingredients on chick performance: effect on phosphorus availability, metabolizable energy value and carcass composition. Poultry Sci. 47:1140-1148. Blakely, R. M., H. I. MacGregor and D. Hanoi, 1963. The effect of type of pelleting on growth and metabolizable energy from turkey rations. Brit. Poultry Sci. 4 : 2 6 1 - 2 6 5 . Calet, C , 1965. The relative value of pellets versus mash and grain in poultry nutrition. World's Poultry Sci. J. 2 1 : 2 3 - 5 2 . Cave, N. A. G., S. J. Slinger, J. D. Summers and G. C. Ashton, 1965. The nutritional value of wheat milling by-products for the growing chick. 1. Availability of energy. Cereal Chem. 42:523—532. Coates, B. J., 1973. Chemical methods for the prediction of the metabolizable energy content of
Downloaded from http://ps.oxfordjournals.org/ at Gazi Universitesi on May 1, 2015
TABLE 2.—The mean T.M.E. values of three diets fed as mash, pellets and reground pellets
1688
I. R. SIBBALD
wheats and barleys. M.Sc. Thesis, University of Guelph, Guelph, Ontario. Reddy, C. V., L. S. Jensen, L. H. Merrill and J. McGinnis, 1962. Influence of mechanical alteration of dietary density on energy available for chick growth. J. Nutrition, 77:428-432. Sell, J. L., and O. J. Thompson, 1965. The effects of ration pelleting and level of fat on the efficiency of nutrient utilization by the chicken. Brit. Poultry Sci. 6:345-354. Sibbald, I. R., 1975. The effect of level of feed intake on metabolizable energy values measured with adult roosters. Poultry Sci. 54:1990-1997. Sibbald, I. R., 1976a. The effect of cold pelleting on
the true metabolizable energy values of cereal grains fed to adult roosters and a comparison of observed with predicted metabolizable energy values. Poultry Sci. 55:970-974. Sibbald, I. R., 1976b. A bioassay for true metabolizable energy in feedingstuffs. Poultry Sci. 55:303-308. Summers, J. D., 1975. Effect of processing on the nutritive value of poultry feeds. Proc. Georgia Nutr. Conf. pp. 113-130. Summers, J. D., H. U. Bentley and S. J. Slinger, 1968. Influence of method of pelleting on utilization of energy from corn, wheat, shorts and bran. Cereal Chem. 45:612-614.
Downloaded from http://ps.oxfordjournals.org/ at Gazi Universitesi on May 1, 2015
INTRODUCTION There is evidence that the apparent metabolizable energy (A.M.E.) values of some feedingstuffs are increased by steam pelleting (Reddy et al., 1962). However, the effect of pelleting is not consistent (Blakely et al., 1963; Sell and Thompson, 1965). It appears that steam pelleting has the most marked effects when the feedingstuff contains either high levels of fibre or heat labile growth depressants (Cave et al., 1965; Bayley et al., 1968; Summers et al, 1968; Summers, 1975). There is no published information describing the effect of steam pelleting on the T.M.E. values of feedingstuffs. Sibbald (1976a) compared the T.M.E. of whole and cold pelleted grains but the data are not directly relevant because the pelleting process caused the grain kernels to be broken. The effects observed may have been caused by disruption of the kernels rather than by the production of pellets. The purpose of the present work was to measure the effects of steam pelleting on the T.M.E. values of poultry diets. MATERIALS AND METHODS Experiment 1. Seven diets, prepared as mash and steam pellets, were each assayed four times for T.M.E. by the method of Sibbald (1976b). Additional measurements were made on reground pellets. The diets included corn:wheat: soybean broiler starter and finisher diets (1,2),
1
Contribution No. 698, Animal Research Institute.
a corn:soybean chick starter (3), diets similar to 3 but supplemented with 20 and 30% of rapeseed meal (4,5), diet 5 supplemented with 1 p.p.m. of selenium (6), and diet 5 supplemented with 0.25% of potassium carbonate (7). A t-test was used to determine if the T.M.E. values of the mash and pelleted forms of a diet were significantly different. Experiment 2. Three diets, prepared as mash and steam pellets, were each assayed seven times for T.M.E. while additional measurements were made on reground pellets. The diets, which were prepared in a commercial mill, included a breeding hen diet (1), a turkey broiler finisher (2), and a chicken broiler finisher (3). RESULTS The data obtained are summarized as means in Tables 1 and 2. The differences between the mash and pelleted forms of the diets were small and exhibited no consistent trend. The absence of significant (P<0.05) differences was confirmed by the series of t-tests. The reground pellets of diet 5 (Table 1) appeared to contain more T.M.E. than did the intact pellets (3.96 vs. 3.72 kcal./g.). However, the mean for the reground pellets was based on only two determinations and a t-test showed that the difference was not significant. DISCUSSION Practical diets of the types evaluated in experiment 2 are expected to be low in fibre and essentially free of heat labile growth
1686
Downloaded from http://ps.oxfordjournals.org/ at Gazi Universitesi on May 1, 2015
ABSTRACT Two experiments were made to measure the effects of steam pelleting on the true metabolizable energy (T.M.E.) values of ten poultry diets. None of the differences between the T.M.E. values of the diets before and after pelleting was significant (P>0.05). A small number of observations demonstrated that the T.M.E. values of reground and intact pellets were similar. It was concluded that, under the conditions of the two experiments, steam pelleting did not change the T.M.E. values of the diets. Poultry Science 56:1686-1688, 1977
RESEARCH NOTE
1687
TABLE 1.—The mean T.M.E. values of seven diets fed as mash, steam pellets and reground pellets
Diet
Mash1
Pellets'
Reground pellets2
3.64 3.95 3.66 3.65 3.74 3.73 3.67
3.65 3.92 3.63 -3.73 3.72 3.74 3.66
3.65 3.80 3.58 3.58 3.96 3.68 3.70
± 0.05 + 0.01 ±0.06 ±0.02 ± 0.04 ± 0.02 ± 0.05
±0.02 + 0.04 ± 0.07 ± 0.05 ± 0.03 ± 0.06 ±0.02
1
Data are means, with standard errors, of 4 determinations expressed as kcal./g. of dry matter.
2
Data are means of the number of determinations shown in brackets.
±0.04 (3) ± 0.09 (3) ±0.12 (2) ± 0.02 (2) ± 0.03 (2) ± 0.03 (3) ± 0.08 (3)
Diet
Mash1
Pellets1
Reground pellets2
3.38 ±0.03 3.88 ± 0.03 3.76 ± 0.05
3.40 ±0.03 3.81 ± 0.02 3.73 ± 0.02
3.47 ± 0.01 (3) 3.78 + 0.02(3) 3.73 ± 0.06 (4)
1
Data are means, with standard errors, of 7 determinations expressed as kcal./g. of dry matter.
2
Data are means of the number of determinations shown in brackets.
depressants; c o n s e q u e n t l y , it is n o t surprising t h a t their T.M.E. values were n o t improved b y steam pelleting. However, diets 4 t o 7 of e x p e r i m e n t 1 c o n t a i n e d from 2 0 t o 30% of rapeseed meal which is a r a t h e r fibrous feedingstuff b u t again steam pelleting was w i t h o u t effect. In a review of t h e effects of s t e a m pelleting Calet ( 1 9 6 5 ) presents evidence t h a t birds t e n d t o eat m o r e pellets t h a n mash. This difference in voluntary feed intake, if large, could have a p r o f o u n d effect u p o n t h e A.M.E. value of a diet (Sibbald, 1 9 7 5 ) . It seems possible t h a t s o m e of t h e differences in energy availability a t t r i b u t e d t o t h e steam pelleting process m a y reflect differences in feed c o n s u m p t i o n . It is interesting t o n o t e t h a t diets 5 and 6 (Table 1) have similar T.M.E. values while differing in selenium c o n t e n t . C o a t e s ( 1 9 7 3 ) observed t h a t naturally occurring selenium affected t h e A.M.E. values of w h e a t s . T h e present work was n o t performed t o investigate t h e effects of selenium; t h e d a t a o b t a i n e d c a n n o t be considered conclusive b u t the possible contradiction suggests a line for f u t u r e work.
ACKNOWLEDGEMENTS T h e a u t h o r is indebted t o Dr. J. D. Summers, University of Guelph for providing t h e diets evaluated in e x p e r i m e n t 1 and t o Dr. H. Likuski, Canada Packers, T o r o n t o , for t h e diets used in e x p e r i m e n t 2. T h a n k s are e x t e n d e d t o Mrs. S. T o b i n for her able technical assistance.
REFERENCES Bayley, H. S., J. D. Summers and S. J. Slinger, 1968. The effect of steam pelleting feed ingredients on chick performance: effect on phosphorus availability, metabolizable energy value and carcass composition. Poultry Sci. 47:1140-1148. Blakely, R. M., H. I. MacGregor and D. Hanoi, 1963. The effect of type of pelleting on growth and metabolizable energy from turkey rations. Brit. Poultry Sci. 4 : 2 6 1 - 2 6 5 . Calet, C , 1965. The relative value of pellets versus mash and grain in poultry nutrition. World's Poultry Sci. J. 2 1 : 2 3 - 5 2 . Cave, N. A. G., S. J. Slinger, J. D. Summers and G. C. Ashton, 1965. The nutritional value of wheat milling by-products for the growing chick. 1. Availability of energy. Cereal Chem. 42:523—532. Coates, B. J., 1973. Chemical methods for the prediction of the metabolizable energy content of
Downloaded from http://ps.oxfordjournals.org/ at Gazi Universitesi on May 1, 2015
TABLE 2.—The mean T.M.E. values of three diets fed as mash, pellets and reground pellets
1688
I. R. SIBBALD
wheats and barleys. M.Sc. Thesis, University of Guelph, Guelph, Ontario. Reddy, C. V., L. S. Jensen, L. H. Merrill and J. McGinnis, 1962. Influence of mechanical alteration of dietary density on energy available for chick growth. J. Nutrition, 77:428-432. Sell, J. L., and O. J. Thompson, 1965. The effects of ration pelleting and level of fat on the efficiency of nutrient utilization by the chicken. Brit. Poultry Sci. 6:345-354. Sibbald, I. R., 1975. The effect of level of feed intake on metabolizable energy values measured with adult roosters. Poultry Sci. 54:1990-1997. Sibbald, I. R., 1976a. The effect of cold pelleting on
the true metabolizable energy values of cereal grains fed to adult roosters and a comparison of observed with predicted metabolizable energy values. Poultry Sci. 55:970-974. Sibbald, I. R., 1976b. A bioassay for true metabolizable energy in feedingstuffs. Poultry Sci. 55:303-308. Summers, J. D., 1975. Effect of processing on the nutritive value of poultry feeds. Proc. Georgia Nutr. Conf. pp. 113-130. Summers, J. D., H. U. Bentley and S. J. Slinger, 1968. Influence of method of pelleting on utilization of energy from corn, wheat, shorts and bran. Cereal Chem. 45:612-614.
Downloaded from http://ps.oxfordjournals.org/ at Gazi Universitesi on May 1, 2015