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The Modifying Effect of Calorie: Protein Ratio on Laying Hen Performance and on the “Extra Metabolic Effect” of Added Fat1
The Modifying Effect of Calorie:Protein Ratio on Laying Hen Performance and on the "Extra Metabolic Effect" of Added Fat 1 FAROUK HORANI* and J. L. SELL 3 Animal Science Department, North Dakota State University, Fargo, North Dakota 58102 (Received for publication March 23, 1977)
Poultry Science 56:1981-1988, 1977
INTRODUCTION
It was evident from two previous studies (Horani and Sell, 1977 and Sell et al, 1976) that feed grade animal fat could be beneficial in laying hen rations when appropriate adjustments in ration formulation were made so as to maintain a desirable calorie:protein ratio. Added fat was also found to exert an "extra metabolic effect" on the metabolic efficiency of laying hens (Horani and Sell, 1977). In certain rations, the apparent M.E. of added fat was found to approach and sometimes exceed the gross energy value. The study reported herein was conducted to further investigate the effects of added fat on the performance characteristics and the metabolic efficiency of laying hens. In particular, the modifying effects of the calorie:protein ratio of the fat supplemented rations on the
1 Published with the approval of the Director of the North Dakota Agricultural Experiment Station as Journal article No. 759. 2 Present address: P.O. Box 19148 Amman, Jordan. 3 Present address: Department of Animal Science, Iowa State University, Ames, Iowa 50010.
laying hen's productivity and efficiency were investigated. MATERIALS AND METHODS A total of 1600 hens were randomly allotted to 25 ration treatments with four replicates used per treatment. There were 16 hens (two hens/cage) per replicate. The experiment started on October 15, 1975, when the hens were about 24 weeks old and had attained a rate of egg production of approximately 50%. The hens were housed in stair-type cages (30 x 40 cm.) and feed and water were provided ad lib. The experiment lasted for nine, 28-day periods. There were 25 ration treatments used. Fifteen of these involved three levels of feed grade animal fat (0, 3 or 6%) in a complete factorial arrangement with five rations based on corn (C), oats (T), barley (B), corn with 30% oats (C+T), or corn with 30% barley (C+B). The calorie to protein ratio of all fifteen rations was kept constant (176 kcal. of M.E. per kg. for each % of protein) by making appropriate adjustments in the soybean meal and grain levels. Therefore, this series of rations will be referred to as the "adjusted" series. The ingredient composition of these "adjusted" rations is presented in Table 1.
1981
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ABSTRACT Feed grade animal fat (3 or 6%) was included in two series of laying hen rations that were based on corn, oats, barley, corn with aats or corn with barley. In the first series, the calorie:protein ratio was adjusted to a constant value while in the second series, fat was substituted for an equal amount of the grain portion with no adjustment in the calorie: protein ratios of the rations. Generally, fat was found to decrease feed consumption and improve feed efficiency. Rations with a constant calorie:protein ratio were slightly better utilized than those with wider ratios. All fat supplemented rations supported an excellent level of egg production, and there was no adverse effects of fat on laying hen performance. The "extra metabolic effect" of added fat was prominent in all rations based on corn while this effect was variable in rations based on oats or barley. Fat exerted an "extra metabolic effect" when included at a 3% level in oat- or barley-based rations that had a constant calorie:protein ratio. This effect of fat was not observed in oat- or barley-based rations with unadjusted calorie:protein ratios or with 6% added fat. Thus it appeared that the "extra metabolic effect" of added fat was dependent on the grain portion of the ration, the level of added fat and the calorie:protein ratio.
F. HORANI AND J. L. SELL
1982
TABLE l.—Tbe ingredient composition oftbe rations taitb 0, 3 and 6% added fat, and constant calorie to protein ratio (adjusted) No added fat rations
C
T
B
C+T
C+B
Corn Oats Barley Soybean meal (44%) Constant portion1
69.4
...
.. .
83.0
44.4 30.0
44.5
20.0 10.6
6.4 10.6
83.8 5.6 10.6
15.0 10.6
30.0 14.9 10.6
3% added fat rations
3C
3T
3B
3C+T
3C+B
Com Oats Barley Soybean meal (44%) Constant portion1 Fat
64.0
...
...
.. .
76.5
39.0 30.0
22.4 10.6 3.0
9.9 10.6 3.0
77.4 9.0 10.6 3.0
...
17.4 10.6 3.0
30.0 17.2 10.6 3.0
6% added fat rations
6C
6T
6B
6C+T
6C+B
...
33.6 30.0
33.9
(% of the ration)
58.7
. ..
70.1
24.7 10.6 6.0
13.3 10.6 6.0
70.9 12.5 10.6 6.0
19.8 10.6 6.0
39.2
...
30.0 19.5 10.6 6.0
1
The constant portion contributed the following as a percent of the ration: meat and bone meal, 2.0; ground limestone, 6.0; dicalcium phosphate, 2.0;salt premix 3 , 0.3 ; vitamin premix 3 , 0.25;and DL-methionine, 0.05. 2
The salt premix supplied 30 p.p jn. of Mn. and 2.9 g. of NaCl per kg. of ration.
3
The vitamin premix was supplied by Gold Label Feeds, Inc., West Fargo, North Dakota, and it contained the following per kg. of premix: vitamin A, 4.4 million U.S.P.; vitamin D 3 , 1 . 7 6 million I.C.U.; vitamin E, 3520 I.U.; vitamin B 1 2 , 5.3 fig.; riboflavin, 2.64 g.; niacin, 13.2 g.;menadione sodium bisulfite complex, 880/ig.; folic acid, 176 mg.; choline, 264 g.; D-pantothenic acid, 2.64 g.; ethoxyquin, 50 g.
TABLE 2.—Tbe ingredient composition oftbe rations with 3 and 6% added fat, and different calorie to protein ratios (unadjusted) 3% added fat rations
3Cu
3Tu
3Bu
3C+Tu
3C+Bu
41.4 30.0
41.5
.. . 15.0 10.6 3.0
30.0 14.9 10.6 3.0
6C+Tu
6C+Bu
38.4 30.0
38.5
...
30.0 14.9 10.6 6.0
(% of the ration) Corn Oats Barley Soybean meal (44%) Constant portion1 Fat
66.4
...
. ..
80.0
20.0 10.6 3.0
6.4 10.6 3.0
80.8 5.6 10.6 3.0
6% added fat rations
6Cu
6Tu
6Bu
Corn Oats Barley Soybean meal (44%) Constant portion1 Fat
63.4
'See Table 1.
.. . ...
20.0 10.6 6.0
... .. .
77.0
.. .
6.4 10.6 6.0
77.8 5.6 10.6 6.0
15.0 10.6 6.0
...
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Corn Oats Barley Soybean meal (44%) Constant portion1 Fat
... ...
CALORIE:PROTEIN RATIO AND DIETARY FAT FOR HENS
RESULTS AND DISCUSSION The 252-day performance of the laying hens fed the fifteen "adjusted" rations and the ten "unadjusted" rations is presented in Tables 3 and 4, respectively. The effects of fat supplementation on the laying hen performance were essentially the same as those previously discussed by Horani and Sell (1977). In general, the addition of fat to the various rations resulted in significant (P<0.01) reductions in feed intake with concomitant improvements in feed efficiency, expressed as kg. feed/kg. eggs or kg. feed/dozen of eggs. Egg production averaged more than 82% for all hens included in the experiment, and there was no significant (P<0.10) effect of fat on this parameter.
However, the addition of fat significantly (P<0.05) increased the body weight gain of the laying hens. There was no effect of fat on mortality, which, in fact, was less than 5% among all hens included in the experiment. As the level of added fat increased (0, 3 and 6%) average hen-day feed consumption, irrespective of the calorie: protein ratio and the grain source, was decreased (116.9, 112.1 and 108.8 g), feed efficiency was improved (2.42, 2.25 and 2.19 kg. feed/kg. eggs), % hen-day egg production was not altered noticeably (81.2, 82.7 and 82.4), gain in weight was increased (241, 317 and 353 g./hen) and egg size was not affected (59.9, 60.3 and 60.3 g., respectively). These results are in agreement with those reported by Horani and Sell (1977) in that additions of up to 6% fat to laying hen rations based on corn, oats or barley resulted in appreciable improvements in feed efficiency without adversely affecting any other production characteristics. There were significant differences (P<0.05) in feed consumption and feed efficiency (kg. feed/kg. egg) between the "adjusted" and the "unadjusted" fat supplemented rations. Hens fed the "unadjusted" rations consumed more feed and were less efficient than those fed the "adjusted" fat supplemented rations. There were also significant (P<0.01) differences in feed consumption and feed efficiency between rations with 3% added fat and those with 6%. Hens fed rations with 6% added fat consumed less feed and were more efficient than those fed rations with 3% added fat. Also hens fed rations with 6% added fat gained more body weight than hens fed rations with 3% added f a t This increase in body weight gain was significant (P<0.05) only when hens were fed the "unadjusted" 6% added fat rations. Even though the calorie to protein ratio in the "adjusted" rations was constant, rations with added fat were utilized significantly (P<0.01) better than rations with no added fat. The effects of the main energy source (the grain) in the ration on hen performance were also significant (P<0.01 for feed consumption and feed efficiency, and P<0.05 for egg production). The performance data of laying hens with respect to the source of grain in the various rations fed are presented in Table 5. It was evident that regardless of the level of fat and the calorie to protein ratio of the ration (adjusted vs. unadjusted), rations based on corn
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The other ten rations constituted the "unadjusted" series since fat was substituted, at either the 3 or 6% level, directly for grain on a weight basis, and no adjustments were made for changes in calorie to protein ratio. These rations have been given acronyms similar to those of the "unadjusted" series except that the letter " u " succeeds each corresponding acronym. The calorie to protein ratios of these "unadjusted" rations ranged from 187 (kcal. of M.E. per kg. for each percent of protein) for the ration based on corn with 3% added fat (3Cu) to 210 for the ration based on oats with 6% added fat (6Tu). Thus, the calorie to protein ratio of each ration in the "unadjusted" series was wider than that of its counterpart ration in the "adjusted" series. The ingredient composition of the 10 rations in the "unadjusted" series is shown in Table 2. The hens were weighed at the start of the experiment and at the end of the ninth period. Feed consumption, egg production, mortality, and egg weight records were kept as previously described by Horani and Sell (1977). The two replicates of each ration treatment that were located in the lower tiers of the cages were selected for the M.E. measurement during the sixth period (March, 1976). Six hens located in three adjacent cages served as a replicate for ME measurement, and there were three such replicates per ration treatment group. Nitrogen-corrected M.E. values were obtained as described by Hill and Renner (1963). All data obtained were analyzed statistically by analysis of variance according to Snedecor and Cochran (1967).
1983
± 3.0 ±4.2 + 3.7 ± 1.9 ± 3.8
97.0 118.8 112.5 108.3 102.6 107.8
6C 6T 6B 6C+T 6C+B Average
±0.06 ±0.03 + 0.03 ±0.05 ±0.04
±0.05 ±0.06 ±0.12 ±0.02 ±0.07
1.45 1.69 1.62 1.56 1.56 1.58
±0.02 ±0.16 ±0.08 ±0.06 ±0.05
1.50 1.80 1.70 1.55 1.56 1.62
1.56 2.02 1.80 1.64 1.67 1.74
Kg. feed/ dozen eggs
All values are averages of 4 replicates + standard deviation.
± 0.8 ±4.1 ± 3.8 ± 1.4 + 4.1
102.1 119.4 116.6 110.3 107.8 111.2
3C 3T 3B 3C+T 3C+B Average
1
± 2.7 1 + 0.5 ± 1.9 ±1.5 ± 3.1
c
108.9 126.7 123.0 113.9 112.0 116.9
Hen-day feed consumption
T B C+T C+B Average
Ration
1.96 2.34 2.24 2.16 2.14 2.17
2.02 2.50 2.35 2.16 2.15 2.24
2.13 2.78 2.57 2.27 2.33 2.42
80.2 84.4 83.6 83.6 79.2 82.2
82.0 79.4 82.4 85.5 83.0 82.5
±0.07 ±0.04 ±0.04 ± 0.08 ±0.05 ±0.04 ±0.09 ±0.12 ±0.12 ±0.07
83.8 75.7 82.3 83.3 80.7 81.2
± 2.3 + 4.2 ±4.7 ± 1.7 ± 3.7
±3.7 ± 2.7 ±3.8 ±2.3 ± 3.6
±2.4 +6.0 ±3.0 ±2.7 ± 1.6
Hen-day production (%)
±0.02 ±0.19 + 0.12 ±0.07 + 0.07
Kg. feed/ kg. eggs
TABLE i.—The 252-day performance of laying hens fed the rations with 0, 3 and 6% added fat, and const
ded from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
5.5 1 2.6 3.3 3.1 5.1
± 4.4 ±4.2 ± 1.8 ± 2.2 ± 0.6
± ± ± ± ±
±0.06 ±0.04 ±0.08 ±0.05 ±0.06
±0.03 ±0.05 ±0.05 ±0.05 ±0.10
1.48 1.90 1.72 1.59 1.50 1.64
1.40 1.80 1.72 1.56 1.50 1.60
Kg. feed/ dozen eggs
All values are averages of 4 replicates ± standard deviation.
97.6 121.3 117.2 109.2 103.4 109.7
6Cu 6Tu 6Bu 6C+Tu 6C+Bu Average
1
100.6 125.6 118.4 110.0 109.9 112.9
Hen-day feed consumption (g.)
3Cu 3Tu 3Bu 3C+Tu 3C+Bu Average
Ration
1.89 2.51 2.44 2.15 2.09 2.22
2.03 2.62 2.41 2.19 2.09 2.27
0.07 0.06 0.13 0.06 0.02
±0.03 ± 0.07 ± 0.07 ±0.08 ± 0.10
± ± ± ± ±
Kg. feed/ kg. eggs
± ± ± ± ±
83.7 80.8 81.8 84.3 82.8 82.7
2.1 2.8 1.5 1.2 5.0
±3.0 ± 2.4 ± 2.9 ± 3.1 ± 0.9
81.7 79.2 82.6 83.2 88.0 82.9
Hen-day production (%)
TABLE 4.-The 252-day performance of laying hens fed the rations with 3 and 6% added fat, and different ca
d from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
1986
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were utilized better by laying hens than were rations based on either barley or oats. The utilization of the rations based on corn with oats or with barley was less dramatically improved by the blend of the grains in this experiment than had been observed in a preious study (Horani and Sell, 1977). This could be explained on the basis that the ratio of oats or barley to corn in these rations was greater than the favorable ratio (1:2) used in the previous study. The calculated as well as the determined M.E. values of the various rations are presented in Table 6. There was excellent agreement among the replications within each treatment as shown by the relatively small standard deviations for most of the means. Generally, the calculated M.E. values were higher than the determined M.E. values. Exceptions were the M.E. values of the "adjusted" rations with 3% added fat in which case the measured M.E. values were generally higher than the calculated values. Utilizing the data of Table 6 calculated (expected) vs. the measured (observed) changes in M.E. of the "adjusted" rations due to the addition of 3 or 6% fat were obtained. The changes in ration M.E.'s due to adding fat to radons with adjusted calorie: protein ratio and to rations with unadjusted calorie:protein ratios are presented in Tables 7 and 8, respectively. The observed changes in M.E. were greater than the expected changes when 3% fat was added to the rations. Thus, the quantity (B-A) was always positive, and it was the greatest in the ration based on oats (T). The average summation of these "extra metabolizable calories" (B-A) was 50 kcal./kg. of ration. If these extra calories were attributed to the addition of 3% fat to the rations, then the apparent M.E. of fat (calculated by the method described previously by Horani and Sell, 1977) would be about 9165 kcal./kg. far, However, the addition of 6% fat to four of the five rations (Table 7) resulted in observed changes in M.E. that were smaller than the expected changes. Thus, the quantity (B-A) was negative for these four rations, and the apparent M.E. value of fat was calculated to be about 6500 kcal./kg. In the ration where corn was the sole grain used, the addition of 6% fat resulted in 100 "extra metabolizable kilocalories" per kg. of ration. Accordingly, the apparent M.E. of fat in that ration was calculated to be 9165 kcaL/kg.
CALORIE:PROTEIN RATIO AND DIETARY FAT FOR HENS
1987
s & 8 fr c a
T>
JJ ei> u 4J
^ ^rt
3rt 3Nrt
>
S3 3
>oli
N
O
= u -a < S u
It is of great interest to note that when the calorie to protein ratio was adjusted, the addition of 3% fat to the rations resulted in an apparent M.E. of fat of about 9165 kcal./kg., while when the calorie to protein ratio was not adjusted the M.E. of fat appeared to be less than 7500 kcal./kg. However, when the level of added fat was 6%, the M.E. of fat appeared to be less than its reference value in both the "adjusted" and "unadjusted" rations. Exceptions to these observations were the corn-based rations in which the apparent M.E. of fat was always greater than the reference value, ranging from 8,500-11,000 kcal./kg. of fat. Apparently, favorable interactions occurred between added fat and other components of certain rations (corn-based rations in particular) which ultimately increased the absorption and/
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
When no adjustments in the calorie to protein ratios of the various rations were made, the addition of either 3 or 6% fat to rations containing oats or barley resulted in an apparent M.E. of fat that was below the reference M.E. value used in calculations. However, this was not the case with the rations based on corn alone. In fact, the addition of 3 or 6% fat to the corn-based ration (ration Cu) resulted in an apparent M.E. of fat that exceeded 10,300 kcal./kg. Thus, regardless of the calorie to protein ratio of the ration the addition of 3 or 6% fat to a ration whose major energy source (the grain) was corn, resulted in measurable "extra metabolizable calories" of large magnitude. The average of these extra calories indicated that the apparent M.E. of fat was in excess of its gross energy value when fat was added to corn-based rations. Horani and Sell (1977) suggested the term "extra metabolic effect" to describe the apparent increase in the M.E. of fat when it was added to laying hen rations. It is difficult to fully relate this "extra metabolic effect" of added fat to an interaction between the saturated fatty acids of the added feed grade animal fat and the unsaturated fatty acids of the ether extract of the basal ration as suggested by Leeson and Summers (1976). The fact that this "extra metabolic" effect of fat was observed occasionally in rations based on barley, whose lipid portion was mainly saturated, and the fact that this effect was inconsistent in rations based on oats, whose lipid portion was mainly unsaturated, made it difficult to fully interpret the mechanism of the "extra metabolic" effect of fat in terms of fatty acid synergism.
1988
F. HORANI AND J. L. SELL TABLE 7 .—Calculated (expected) vs. measured (observed) changes in ME of the (adjusted) rations due to the addition of 3 and 6% fat 3% fat
6% fat
Ration
A Expected change
B Observed change
B-A Extra calories
A Expected change
B Observed change
B-A Extra calories
C T B C+T C+B
60 1 165 155 90 105
90* 300 210 110 115
+30 +135 +55 +20 +10
180 3 300 300 200 200
280" 240 240 145 140
+100 -60 -60 -55 -60
6 0 = calculated M.E. of ration 3C — that of ration C, etc. 90 = measured M.E. of ration 3C - that of ration C, etc.
3
180 = calculated M.E. of ration 6C — that of ration C, etc.
4
280 = measured M.E. of ration 6C — that of ration C, etc.
or utilization of energy-yielding dietary constituents. It is logical to assume that the "extra metabolic effect" of added fat, which was observed as extra M.E. was a reflection of these favorable interactions. Generally, the "extra metabolic effect" occurred when the level of added fat was less than 6%, and when the calorie to protein ratio of the fat supplemented ration was adjusted to a satisfactory value. However, it should be noted that the "extra metabolic effect" of added fat in corn-based rations was consistently prominent regardless of the level of fat and/or the calorie to protein ratio.
REFERENCES Hill, F. W. and R. Renner, 1963. Effect of heat treatment on the metabolizable energy value of soybeans and extracted soybean flakes for the hen. J. Nutr. 80:375-380. Horani, F. and J. L. Sell, 1977. Effect of feed grade animal fat laying hen performance and on metabolizable energy of rations. Poul. Sci. 56:1972-1980. Leeson, S. and J. D. Summers, 1976. Fat ME Values: The effect of fatty acid saturation. Feedstuffs 48(46): 2 6 - 2 8 . Sell, J. L., F. Horani and R. L. Johnson, 1976. The "extra-caloric" effect of fat in laying hen rations. Feedstuffs 48(27): 2 8 - 2 9 . Snedecor, G. W. and W. G. Cochran, 1967. Statistical Methods. Iowa State University Press, Ames. Iowa.
TABLE 8 . - Calculated (expected) vs. measured (observed) changes in ME of the (unadjusted) rations due to the addition of 3 and 6% fat 3% fat
Ration
A Expected change
B Observed change
Cu Tu Bu C+Tu C+Bu
100' 150 165 115 125
185 2 105 30 95 120
1
6% fat B-A Extra calories +85 ^5 -135 -20 -5
1 0 0 = calculated M.E. of ration 3Cu — that of ration C, etc.
2
185 = measured M.E. of ration 3Cu — that of ration C, etc.
3
220 = calculated M.E. of ration 6Cu - that of ration C, etc.
4
430 = measured M.E. of ration 6Cu — that of ration C, etc.
A Expected change
B Observed change
B-A Extra calories
220 3 300 315 250 250
430" 205 225 230 185
+210 -95 -90 -20 -65
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
1 2
Poultry Science 56:1981-1988, 1977
INTRODUCTION
It was evident from two previous studies (Horani and Sell, 1977 and Sell et al, 1976) that feed grade animal fat could be beneficial in laying hen rations when appropriate adjustments in ration formulation were made so as to maintain a desirable calorie:protein ratio. Added fat was also found to exert an "extra metabolic effect" on the metabolic efficiency of laying hens (Horani and Sell, 1977). In certain rations, the apparent M.E. of added fat was found to approach and sometimes exceed the gross energy value. The study reported herein was conducted to further investigate the effects of added fat on the performance characteristics and the metabolic efficiency of laying hens. In particular, the modifying effects of the calorie:protein ratio of the fat supplemented rations on the
1 Published with the approval of the Director of the North Dakota Agricultural Experiment Station as Journal article No. 759. 2 Present address: P.O. Box 19148 Amman, Jordan. 3 Present address: Department of Animal Science, Iowa State University, Ames, Iowa 50010.
laying hen's productivity and efficiency were investigated. MATERIALS AND METHODS A total of 1600 hens were randomly allotted to 25 ration treatments with four replicates used per treatment. There were 16 hens (two hens/cage) per replicate. The experiment started on October 15, 1975, when the hens were about 24 weeks old and had attained a rate of egg production of approximately 50%. The hens were housed in stair-type cages (30 x 40 cm.) and feed and water were provided ad lib. The experiment lasted for nine, 28-day periods. There were 25 ration treatments used. Fifteen of these involved three levels of feed grade animal fat (0, 3 or 6%) in a complete factorial arrangement with five rations based on corn (C), oats (T), barley (B), corn with 30% oats (C+T), or corn with 30% barley (C+B). The calorie to protein ratio of all fifteen rations was kept constant (176 kcal. of M.E. per kg. for each % of protein) by making appropriate adjustments in the soybean meal and grain levels. Therefore, this series of rations will be referred to as the "adjusted" series. The ingredient composition of these "adjusted" rations is presented in Table 1.
1981
Downloaded from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
ABSTRACT Feed grade animal fat (3 or 6%) was included in two series of laying hen rations that were based on corn, oats, barley, corn with aats or corn with barley. In the first series, the calorie:protein ratio was adjusted to a constant value while in the second series, fat was substituted for an equal amount of the grain portion with no adjustment in the calorie: protein ratios of the rations. Generally, fat was found to decrease feed consumption and improve feed efficiency. Rations with a constant calorie:protein ratio were slightly better utilized than those with wider ratios. All fat supplemented rations supported an excellent level of egg production, and there was no adverse effects of fat on laying hen performance. The "extra metabolic effect" of added fat was prominent in all rations based on corn while this effect was variable in rations based on oats or barley. Fat exerted an "extra metabolic effect" when included at a 3% level in oat- or barley-based rations that had a constant calorie:protein ratio. This effect of fat was not observed in oat- or barley-based rations with unadjusted calorie:protein ratios or with 6% added fat. Thus it appeared that the "extra metabolic effect" of added fat was dependent on the grain portion of the ration, the level of added fat and the calorie:protein ratio.
F. HORANI AND J. L. SELL
1982
TABLE l.—Tbe ingredient composition oftbe rations taitb 0, 3 and 6% added fat, and constant calorie to protein ratio (adjusted) No added fat rations
C
T
B
C+T
C+B
Corn Oats Barley Soybean meal (44%) Constant portion1
69.4
...
.. .
83.0
44.4 30.0
44.5
20.0 10.6
6.4 10.6
83.8 5.6 10.6
15.0 10.6
30.0 14.9 10.6
3% added fat rations
3C
3T
3B
3C+T
3C+B
Com Oats Barley Soybean meal (44%) Constant portion1 Fat
64.0
...
...
.. .
76.5
39.0 30.0
22.4 10.6 3.0
9.9 10.6 3.0
77.4 9.0 10.6 3.0
...
17.4 10.6 3.0
30.0 17.2 10.6 3.0
6% added fat rations
6C
6T
6B
6C+T
6C+B
...
33.6 30.0
33.9
(% of the ration)
58.7
. ..
70.1
24.7 10.6 6.0
13.3 10.6 6.0
70.9 12.5 10.6 6.0
19.8 10.6 6.0
39.2
...
30.0 19.5 10.6 6.0
1
The constant portion contributed the following as a percent of the ration: meat and bone meal, 2.0; ground limestone, 6.0; dicalcium phosphate, 2.0;salt premix 3 , 0.3 ; vitamin premix 3 , 0.25;and DL-methionine, 0.05. 2
The salt premix supplied 30 p.p jn. of Mn. and 2.9 g. of NaCl per kg. of ration.
3
The vitamin premix was supplied by Gold Label Feeds, Inc., West Fargo, North Dakota, and it contained the following per kg. of premix: vitamin A, 4.4 million U.S.P.; vitamin D 3 , 1 . 7 6 million I.C.U.; vitamin E, 3520 I.U.; vitamin B 1 2 , 5.3 fig.; riboflavin, 2.64 g.; niacin, 13.2 g.;menadione sodium bisulfite complex, 880/ig.; folic acid, 176 mg.; choline, 264 g.; D-pantothenic acid, 2.64 g.; ethoxyquin, 50 g.
TABLE 2.—Tbe ingredient composition oftbe rations with 3 and 6% added fat, and different calorie to protein ratios (unadjusted) 3% added fat rations
3Cu
3Tu
3Bu
3C+Tu
3C+Bu
41.4 30.0
41.5
.. . 15.0 10.6 3.0
30.0 14.9 10.6 3.0
6C+Tu
6C+Bu
38.4 30.0
38.5
...
30.0 14.9 10.6 6.0
(% of the ration) Corn Oats Barley Soybean meal (44%) Constant portion1 Fat
66.4
...
. ..
80.0
20.0 10.6 3.0
6.4 10.6 3.0
80.8 5.6 10.6 3.0
6% added fat rations
6Cu
6Tu
6Bu
Corn Oats Barley Soybean meal (44%) Constant portion1 Fat
63.4
'See Table 1.
.. . ...
20.0 10.6 6.0
... .. .
77.0
.. .
6.4 10.6 6.0
77.8 5.6 10.6 6.0
15.0 10.6 6.0
...
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Corn Oats Barley Soybean meal (44%) Constant portion1 Fat
... ...
CALORIE:PROTEIN RATIO AND DIETARY FAT FOR HENS
RESULTS AND DISCUSSION The 252-day performance of the laying hens fed the fifteen "adjusted" rations and the ten "unadjusted" rations is presented in Tables 3 and 4, respectively. The effects of fat supplementation on the laying hen performance were essentially the same as those previously discussed by Horani and Sell (1977). In general, the addition of fat to the various rations resulted in significant (P<0.01) reductions in feed intake with concomitant improvements in feed efficiency, expressed as kg. feed/kg. eggs or kg. feed/dozen of eggs. Egg production averaged more than 82% for all hens included in the experiment, and there was no significant (P<0.10) effect of fat on this parameter.
However, the addition of fat significantly (P<0.05) increased the body weight gain of the laying hens. There was no effect of fat on mortality, which, in fact, was less than 5% among all hens included in the experiment. As the level of added fat increased (0, 3 and 6%) average hen-day feed consumption, irrespective of the calorie: protein ratio and the grain source, was decreased (116.9, 112.1 and 108.8 g), feed efficiency was improved (2.42, 2.25 and 2.19 kg. feed/kg. eggs), % hen-day egg production was not altered noticeably (81.2, 82.7 and 82.4), gain in weight was increased (241, 317 and 353 g./hen) and egg size was not affected (59.9, 60.3 and 60.3 g., respectively). These results are in agreement with those reported by Horani and Sell (1977) in that additions of up to 6% fat to laying hen rations based on corn, oats or barley resulted in appreciable improvements in feed efficiency without adversely affecting any other production characteristics. There were significant differences (P<0.05) in feed consumption and feed efficiency (kg. feed/kg. egg) between the "adjusted" and the "unadjusted" fat supplemented rations. Hens fed the "unadjusted" rations consumed more feed and were less efficient than those fed the "adjusted" fat supplemented rations. There were also significant (P<0.01) differences in feed consumption and feed efficiency between rations with 3% added fat and those with 6%. Hens fed rations with 6% added fat consumed less feed and were more efficient than those fed rations with 3% added fat. Also hens fed rations with 6% added fat gained more body weight than hens fed rations with 3% added f a t This increase in body weight gain was significant (P<0.05) only when hens were fed the "unadjusted" 6% added fat rations. Even though the calorie to protein ratio in the "adjusted" rations was constant, rations with added fat were utilized significantly (P<0.01) better than rations with no added fat. The effects of the main energy source (the grain) in the ration on hen performance were also significant (P<0.01 for feed consumption and feed efficiency, and P<0.05 for egg production). The performance data of laying hens with respect to the source of grain in the various rations fed are presented in Table 5. It was evident that regardless of the level of fat and the calorie to protein ratio of the ration (adjusted vs. unadjusted), rations based on corn
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The other ten rations constituted the "unadjusted" series since fat was substituted, at either the 3 or 6% level, directly for grain on a weight basis, and no adjustments were made for changes in calorie to protein ratio. These rations have been given acronyms similar to those of the "unadjusted" series except that the letter " u " succeeds each corresponding acronym. The calorie to protein ratios of these "unadjusted" rations ranged from 187 (kcal. of M.E. per kg. for each percent of protein) for the ration based on corn with 3% added fat (3Cu) to 210 for the ration based on oats with 6% added fat (6Tu). Thus, the calorie to protein ratio of each ration in the "unadjusted" series was wider than that of its counterpart ration in the "adjusted" series. The ingredient composition of the 10 rations in the "unadjusted" series is shown in Table 2. The hens were weighed at the start of the experiment and at the end of the ninth period. Feed consumption, egg production, mortality, and egg weight records were kept as previously described by Horani and Sell (1977). The two replicates of each ration treatment that were located in the lower tiers of the cages were selected for the M.E. measurement during the sixth period (March, 1976). Six hens located in three adjacent cages served as a replicate for ME measurement, and there were three such replicates per ration treatment group. Nitrogen-corrected M.E. values were obtained as described by Hill and Renner (1963). All data obtained were analyzed statistically by analysis of variance according to Snedecor and Cochran (1967).
1983
± 3.0 ±4.2 + 3.7 ± 1.9 ± 3.8
97.0 118.8 112.5 108.3 102.6 107.8
6C 6T 6B 6C+T 6C+B Average
±0.06 ±0.03 + 0.03 ±0.05 ±0.04
±0.05 ±0.06 ±0.12 ±0.02 ±0.07
1.45 1.69 1.62 1.56 1.56 1.58
±0.02 ±0.16 ±0.08 ±0.06 ±0.05
1.50 1.80 1.70 1.55 1.56 1.62
1.56 2.02 1.80 1.64 1.67 1.74
Kg. feed/ dozen eggs
All values are averages of 4 replicates + standard deviation.
± 0.8 ±4.1 ± 3.8 ± 1.4 + 4.1
102.1 119.4 116.6 110.3 107.8 111.2
3C 3T 3B 3C+T 3C+B Average
1
± 2.7 1 + 0.5 ± 1.9 ±1.5 ± 3.1
c
108.9 126.7 123.0 113.9 112.0 116.9
Hen-day feed consumption
T B C+T C+B Average
Ration
1.96 2.34 2.24 2.16 2.14 2.17
2.02 2.50 2.35 2.16 2.15 2.24
2.13 2.78 2.57 2.27 2.33 2.42
80.2 84.4 83.6 83.6 79.2 82.2
82.0 79.4 82.4 85.5 83.0 82.5
±0.07 ±0.04 ±0.04 ± 0.08 ±0.05 ±0.04 ±0.09 ±0.12 ±0.12 ±0.07
83.8 75.7 82.3 83.3 80.7 81.2
± 2.3 + 4.2 ±4.7 ± 1.7 ± 3.7
±3.7 ± 2.7 ±3.8 ±2.3 ± 3.6
±2.4 +6.0 ±3.0 ±2.7 ± 1.6
Hen-day production (%)
±0.02 ±0.19 + 0.12 ±0.07 + 0.07
Kg. feed/ kg. eggs
TABLE i.—The 252-day performance of laying hens fed the rations with 0, 3 and 6% added fat, and const
ded from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
5.5 1 2.6 3.3 3.1 5.1
± 4.4 ±4.2 ± 1.8 ± 2.2 ± 0.6
± ± ± ± ±
±0.06 ±0.04 ±0.08 ±0.05 ±0.06
±0.03 ±0.05 ±0.05 ±0.05 ±0.10
1.48 1.90 1.72 1.59 1.50 1.64
1.40 1.80 1.72 1.56 1.50 1.60
Kg. feed/ dozen eggs
All values are averages of 4 replicates ± standard deviation.
97.6 121.3 117.2 109.2 103.4 109.7
6Cu 6Tu 6Bu 6C+Tu 6C+Bu Average
1
100.6 125.6 118.4 110.0 109.9 112.9
Hen-day feed consumption (g.)
3Cu 3Tu 3Bu 3C+Tu 3C+Bu Average
Ration
1.89 2.51 2.44 2.15 2.09 2.22
2.03 2.62 2.41 2.19 2.09 2.27
0.07 0.06 0.13 0.06 0.02
±0.03 ± 0.07 ± 0.07 ±0.08 ± 0.10
± ± ± ± ±
Kg. feed/ kg. eggs
± ± ± ± ±
83.7 80.8 81.8 84.3 82.8 82.7
2.1 2.8 1.5 1.2 5.0
±3.0 ± 2.4 ± 2.9 ± 3.1 ± 0.9
81.7 79.2 82.6 83.2 88.0 82.9
Hen-day production (%)
TABLE 4.-The 252-day performance of laying hens fed the rations with 3 and 6% added fat, and different ca
d from http://ps.oxfordjournals.org/ at New York University on May 23, 2015
1986
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were utilized better by laying hens than were rations based on either barley or oats. The utilization of the rations based on corn with oats or with barley was less dramatically improved by the blend of the grains in this experiment than had been observed in a preious study (Horani and Sell, 1977). This could be explained on the basis that the ratio of oats or barley to corn in these rations was greater than the favorable ratio (1:2) used in the previous study. The calculated as well as the determined M.E. values of the various rations are presented in Table 6. There was excellent agreement among the replications within each treatment as shown by the relatively small standard deviations for most of the means. Generally, the calculated M.E. values were higher than the determined M.E. values. Exceptions were the M.E. values of the "adjusted" rations with 3% added fat in which case the measured M.E. values were generally higher than the calculated values. Utilizing the data of Table 6 calculated (expected) vs. the measured (observed) changes in M.E. of the "adjusted" rations due to the addition of 3 or 6% fat were obtained. The changes in ration M.E.'s due to adding fat to radons with adjusted calorie: protein ratio and to rations with unadjusted calorie:protein ratios are presented in Tables 7 and 8, respectively. The observed changes in M.E. were greater than the expected changes when 3% fat was added to the rations. Thus, the quantity (B-A) was always positive, and it was the greatest in the ration based on oats (T). The average summation of these "extra metabolizable calories" (B-A) was 50 kcal./kg. of ration. If these extra calories were attributed to the addition of 3% fat to the rations, then the apparent M.E. of fat (calculated by the method described previously by Horani and Sell, 1977) would be about 9165 kcal./kg. far, However, the addition of 6% fat to four of the five rations (Table 7) resulted in observed changes in M.E. that were smaller than the expected changes. Thus, the quantity (B-A) was negative for these four rations, and the apparent M.E. value of fat was calculated to be about 6500 kcal./kg. In the ration where corn was the sole grain used, the addition of 6% fat resulted in 100 "extra metabolizable kilocalories" per kg. of ration. Accordingly, the apparent M.E. of fat in that ration was calculated to be 9165 kcaL/kg.
CALORIE:PROTEIN RATIO AND DIETARY FAT FOR HENS
1987
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It is of great interest to note that when the calorie to protein ratio was adjusted, the addition of 3% fat to the rations resulted in an apparent M.E. of fat of about 9165 kcal./kg., while when the calorie to protein ratio was not adjusted the M.E. of fat appeared to be less than 7500 kcal./kg. However, when the level of added fat was 6%, the M.E. of fat appeared to be less than its reference value in both the "adjusted" and "unadjusted" rations. Exceptions to these observations were the corn-based rations in which the apparent M.E. of fat was always greater than the reference value, ranging from 8,500-11,000 kcal./kg. of fat. Apparently, favorable interactions occurred between added fat and other components of certain rations (corn-based rations in particular) which ultimately increased the absorption and/
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When no adjustments in the calorie to protein ratios of the various rations were made, the addition of either 3 or 6% fat to rations containing oats or barley resulted in an apparent M.E. of fat that was below the reference M.E. value used in calculations. However, this was not the case with the rations based on corn alone. In fact, the addition of 3 or 6% fat to the corn-based ration (ration Cu) resulted in an apparent M.E. of fat that exceeded 10,300 kcal./kg. Thus, regardless of the calorie to protein ratio of the ration the addition of 3 or 6% fat to a ration whose major energy source (the grain) was corn, resulted in measurable "extra metabolizable calories" of large magnitude. The average of these extra calories indicated that the apparent M.E. of fat was in excess of its gross energy value when fat was added to corn-based rations. Horani and Sell (1977) suggested the term "extra metabolic effect" to describe the apparent increase in the M.E. of fat when it was added to laying hen rations. It is difficult to fully relate this "extra metabolic effect" of added fat to an interaction between the saturated fatty acids of the added feed grade animal fat and the unsaturated fatty acids of the ether extract of the basal ration as suggested by Leeson and Summers (1976). The fact that this "extra metabolic" effect of fat was observed occasionally in rations based on barley, whose lipid portion was mainly saturated, and the fact that this effect was inconsistent in rations based on oats, whose lipid portion was mainly unsaturated, made it difficult to fully interpret the mechanism of the "extra metabolic" effect of fat in terms of fatty acid synergism.
1988
F. HORANI AND J. L. SELL TABLE 7 .—Calculated (expected) vs. measured (observed) changes in ME of the (adjusted) rations due to the addition of 3 and 6% fat 3% fat
6% fat
Ration
A Expected change
B Observed change
B-A Extra calories
A Expected change
B Observed change
B-A Extra calories
C T B C+T C+B
60 1 165 155 90 105
90* 300 210 110 115
+30 +135 +55 +20 +10
180 3 300 300 200 200
280" 240 240 145 140
+100 -60 -60 -55 -60
6 0 = calculated M.E. of ration 3C — that of ration C, etc. 90 = measured M.E. of ration 3C - that of ration C, etc.
3
180 = calculated M.E. of ration 6C — that of ration C, etc.
4
280 = measured M.E. of ration 6C — that of ration C, etc.
or utilization of energy-yielding dietary constituents. It is logical to assume that the "extra metabolic effect" of added fat, which was observed as extra M.E. was a reflection of these favorable interactions. Generally, the "extra metabolic effect" occurred when the level of added fat was less than 6%, and when the calorie to protein ratio of the fat supplemented ration was adjusted to a satisfactory value. However, it should be noted that the "extra metabolic effect" of added fat in corn-based rations was consistently prominent regardless of the level of fat and/or the calorie to protein ratio.
REFERENCES Hill, F. W. and R. Renner, 1963. Effect of heat treatment on the metabolizable energy value of soybeans and extracted soybean flakes for the hen. J. Nutr. 80:375-380. Horani, F. and J. L. Sell, 1977. Effect of feed grade animal fat laying hen performance and on metabolizable energy of rations. Poul. Sci. 56:1972-1980. Leeson, S. and J. D. Summers, 1976. Fat ME Values: The effect of fatty acid saturation. Feedstuffs 48(46): 2 6 - 2 8 . Sell, J. L., F. Horani and R. L. Johnson, 1976. The "extra-caloric" effect of fat in laying hen rations. Feedstuffs 48(27): 2 8 - 2 9 . Snedecor, G. W. and W. G. Cochran, 1967. Statistical Methods. Iowa State University Press, Ames. Iowa.
TABLE 8 . - Calculated (expected) vs. measured (observed) changes in ME of the (unadjusted) rations due to the addition of 3 and 6% fat 3% fat
Ration
A Expected change
B Observed change
Cu Tu Bu C+Tu C+Bu
100' 150 165 115 125
185 2 105 30 95 120
1
6% fat B-A Extra calories +85 ^5 -135 -20 -5
1 0 0 = calculated M.E. of ration 3Cu — that of ration C, etc.
2
185 = measured M.E. of ration 3Cu — that of ration C, etc.
3
220 = calculated M.E. of ration 6Cu - that of ration C, etc.
4
430 = measured M.E. of ration 6Cu — that of ration C, etc.
A Expected change
B Observed change
B-A Extra calories
220 3 300 315 250 250
430" 205 225 230 185
+210 -95 -90 -20 -65
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1 2