- Email: [email protected]
Studies with Laying Hens
Studies with Laying Hens 1. EFFECT OF DIETARY FAT, PROTEIN LEVELS AND OTHER VARIABLES IN PRACTICAL RATIONS1 G. F. COMBS AND N. V. HELBACKA
Poultry Department, University of Maryland, College Park, Maryland (Received for publication June 25, 1959)
T
271
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
eluded that 15% protein was adequate during moderate to hot weather. Lillie et al. (1952) observed an improvement in efficiency of egg production as measured by feed requirement when 8% lard was included in the ration. Hill et al. (1956) found that rations containing up to 10% tallow were utilized satisfactorily by layers with less feed required per dozen eggs. On the other hand, McDaniel et al. (1959) observed a high incidence of fatty livers and excessive abdominal fat deposits in caged layers fed high energy diets containing added fat. Sherwood (1958) has recently reviewed nutritional factors which influence egg quality. Berg and Bearse (1956) found significantly higher Haugh unit scores for eggs when hens were fed low energy feeds. Recently, Helbacka and Hall (1958) also reported an increase in Haugh units of eggs from hens fed ammonium chloride. Although egg size is largely determined by heredity and body size, feed can influence it to some extent. Jensen et al. (1957) reported an unidentified factor in yellow corn and corn oil that increased egg size. Others have found an initial depression in egg size when low energy or low protein feeds were used (Thornton et al., 1956; Miller et al, 1957; Berg and Bearse, 1957). Thornton and Moreng (1958, 1959) recently published a report showing that vitamin C was necessary to maintain shell thickness during high environmental temperatures. Titus (1958) improved shell 1 Scientific Article No. A 776, Contribution No. thickness by feeding high calcium levels, 3038 of the Maryland Agricultural Experiment and Wiese et al. (1957) demonstrated a Station (Department of Poultry Husbandry).
HE PROTEIN requirement of laying hens has been studied by many, and widely different apparent results have been obtained. The minimum protein level needed by laying hens, expressed as percent of ration, has been found to be from 12 to 14% by Graham (1934), MacDonald (1938), Miller et al. (1957), Thornton et al. (1957), Adams et al. (1958), and MacIntyre (1958); 16% by Heuser (1941); and from 17 to 18% by Reid et al. (1951), Ingram (1956), and Hochreich et al. (1957). Hill et al. (1956) found that 15% protein was adequate for 5 lb. Leghorns while up to 16.5% protein was needed for 4 lb. Leghorns maintained in heated pens. A protein-energy relationship affecting egg production was observed by Hochreich etal. (1957) and Berg and Bearse (1957). Hens fed a low energy, 14% protein ration supported a rate of lay comparable to that of hens fed a high energy ration containing 18% protein. Milton and Ingram (1957) also observed that older birds needed higher protein levels than pullets. Moreover, Clark et al. (1942) observed that hens fed a high protein containing ration during either the growing or laying period produced more eggs than did controls fed low protein rations through both periods. Milton and Ingram (1957) reported that layers at ambient temperatures of 70°F. to 90°F. needed a higher protein level (18%). Previously, Heywang et al. (1955) had con-
272
G. F. COMBS AND N. V. HELBACKA TABLE 1.—Composition of hen rations Ration designation Ingredient
Ground yellow corn Stabilized fat1 Soybean oil meal, 44% protein Crab meal, 30% protein Meat and bone scrap, 50% prot. Dhy. alfalfa meal, 17% protein (1000,000 IU vit. A/lb.) Limestone, ground Dicalcium phosphate (18% P, 26% Ca) Salt Trace mineral mix2 Choline chloride, 25% mix Vitamin A sup. (2,500 IU/gm.) Vitamin B123 sup. (3 mg./lb.) Special mix Nutrient Content Productive energy,4 Cal./lb. Crude protein, %, as calc. Crude prot. as deter. (Exp. 1) Crude prot. as deter. (Exp. 2) Crude fat, %, as calc. Crude fat, %, as deter. (Exp. 1) C/P ratios (Exp. 1) C/P ratio' (Exp. 2)
A-4
B-1
B-4
C-1
C-4
lbs. per Ion 1,002.0 1,205.5 180.0 180.0 605.0 605.0
D-l
D-4
1,031.7 180.0 480.0 50.0 100.0
1,224.5 180.0 340.0 30.0 60.0
982.0 200.0 605.0
1,185.5 200.0 415.0
E-l &F-1 E-4&F-4
1,355.0
1,528.5
1,381.7
1,549.5
— 440.0
— 280.0
— —
— —
— 320.0 50.0 100.0
— 200.0 30.0 60.0
— —
— —
— —
— —
50.0 90.0
30.0 93.0
50.0 60.0
30.0 75.0
50.0 93.0
30.0 96.0
50.0 65.0
30.0 75.0
50.0 93.0
30.0 96.0
45.0
45.0
20.0
33.0
50.0
50.0
25.0
38.0
50.0
50.0
8.0 1.5 1.5 2.5
2.35 4.15
8.0 1.5 3.5 4.0
2.35 4.15
2,000.0 2,000.0
8.0 1.5 1.5 2.5
0.65 4.15
8.0 1.5 3.5 4.0
1.35 4.15
8.0 1.5 1.5 2.5
2.35 4.15
8.0 1.5 3.5 4.0
2.35 4.15
8.0 1.5 1.5 2.5
0.65 4.15
8.0 1.5 3.5 4.0
1.35 4.15
8.0 1.5 1.5 2.5
2.35 4.15
8.0 1.5 3.5 4.0
2.35 4.15
2,000.0 2,000.0
2,000.0
2,000.0
2,000.0
2,000.0 2,000.0
2,000.0
909.0 16.4 16.4 18.8
968.0 13.3 14.6 15.0
944.0 17.0 17.0
985.0 13.5 14.8
1,019.0 18.6 18.6
1,075.0 14.9 16.4
1,043.0 19.1 19.1
1,096.0 15.3 16.8
1,037.0 18.5
1,093.0 14.8
— 3.5
— 3.5
— 11.9
13.3
55.4 48.4
66.3 64.6
55.5
66.6
11.3 54.8
— 11.9
— 16.8
3.8
— 11.6
— 19.8
3.7
— 12.3
—
—
—
— — 53.5
— — 65.2
2.9 3.3
3.2 3.3
11.6 65.5
—
12.8 54.6
—
10.3 65.2
—
12.6
1 2 3
Hydrolyzed animal and vegetable fat (Proctor & Gamble) in C&D ration series; corn oil in E series; and tallow in F series. Contained 6% manganese, 12% iodine, 2% iron, 0.2% copper, .006% zinc, 0.02% cobalt, and 27% calcium. Supplied per ton (gms.): riboflavin, 2; Ca pantothenate, 5; niacin, 18; choline chloride, 20; procaine penicillin, 3.75; streptomycin sulfate,4 11.25; zinc bacitracin, 5; and 510 I.C.XJ. of vitamin Ds per lb. Fraps (1946) productive energy values used, except that a value of 2900 Calories per lb. was used for fat. 6 Based on protein assay values (NX6.25).
negative relationship between dietary energy and shell thickness. The following studies were initiated to determine the effects of different nutritional variables on egg quality and performance of laying hens. EXPERIMENTAL PROCEDURE Experiment 1. The first experiment involved 32 pens of sixteen lOJ^-month old Single Comb White Leghorn hens (Mt. Hope). These hens had come into production in August but were maintained on range until December since facilities for housing were not then available. During the 24-week experimental period, they were maintained in floor pens with litter in an unheated, open-front type house and provided continuous light. Water, calcite grit, and all-mash experimental rations were supplied ad libitum. The composition of 8 of the 16 rations used in this experiment is given in Table 1
together with their C/P ratios, energy, protein, and fat content. In addition, 8 other rations were used which were obtained by blending certain of the feeds shown in Table 1. For example, ration A2 consisted of 2 parts of ration Al blended with 1 part of ration A4. Similarly, ration A3 was prepared by blending 2 parts of ration A4 and 1 part of ration Al. In this way, rations containing different Calorie/protein ratios ranging from 54.6:1 to 66.6:1 were obtained with energy levels ranging from 909 Calories to 1,096 Calories of productive energy per pound and protein levels ranging from 14.6 to 19.1% (N X 6.25). Eight of the rations fed contained 9% added fat (hydrolyzed animal and vegetable fat) while the other half contained no added fat. Series A and C rations contained no animal protein supplements while Series B and D rations contained 1.5-2.5% crab meal and 3-5% meat and bone scrap. This experiment was divided into three
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Total lbs.
A-1
273
LAYING RATIONS TABLE 2.--Ration
designation and variables used
Experiment 1A Ration Series
Added fat % (Hyd. An. & Veg. Fat)
Animal Protein
0 0 9 9
_
A B C D
Calorie/Protein Ratio 1 54.6-55.5:1
57.9-58.9:1
A-1 B-1 C-1 D-1
A-2 B-2 C-2 D-2
+ +
61.3-62.5:1 A-3 B-3 C-3 D-3
65.2-66.6:1 A-4 B-4 C-4 D-4
Experiment 2 Ration series
J
K 1
Added
added fat, %
(Calorie/Protein Ratio 1
ppm
Tallow Corn oil
48.4-52.5:1 53.0-56.3:1 58.4-60.4: 1 64.6-65.2:1
530 600 600 530 600 600 800 800
— — —
48 48 48 48 48
— 10
— — 10
— 10
—
— — 10 — — 10
A-1 E-l F-l G-l H-l 1-1
A-2 E-2 F-2 G-2 H-2 1-2
-
J-l
J-2
10
K-l
K-2
A-3 E-3 F-3 G-3 H-3 1-3 J-3 K-3
A-4 E-4 F-4 G-4 H-4 1-4
J-4
K-4
Protein level based on NX 6.25.
parts, designated 1A, IB, and IC. The experimental design and rations used in Experiment 1A are given in Table 2. This experiment consisted of 2 related 8-pen factorials in series. Each of these series involved protein level, fat level, and presence or absence of animal protein as variables. Part 2 (Experiment IB) consisted of 8 pens, each of which had free choice of either of two feeds. The combinations were Al and CI, A2 and C2, A3 and C3, A4 and C4, Bl and Dl, B2 and D2, B3 and D3, B4 and D4. Thus, the hens in each pen were able to select their level of fat by varying their consumption of the high and low fat rations. In Experiment IC, 8 pens of hens were permitted free choice consumption of two rations having the widest and narrowest C/P ratios in each ration series, respectively. For example, two replicated groups were each supplied rations Al and A4; two others, Bl and B4; two others, CI and C4; and the last two, Dl and D4. These groups were able to determine their own level of
protein intake and the C/P ratio of the total feed consumed. Daily records of egg production and mortality were kept on a pen basis. In addition, feed consumption and body weight were recorded at 8-week intervals. Measurements were made on egg weight, egg shell thickness, Haugh units, yolk color, and egg inclusions from the last three days' collection of eggs of each 8-week period. In addition, yolk cholesterol and yolk fat contents were determined from eggs collected during the 24th week from each of the 16 pens included in Experiment 1A. Cholesterol was analyzed by a modified method of Zlatkis etal. (1953). Experiment 2. In Experiment 2, 32 pens, each consisting of 24 8J^-month old Single Comb White Leghorn pullets (Mt. Hope), were utilized. The treatments imposed are indicated in Table 2. The composition of ration Series A, E, and F are given in Table 1. Series A rations contained no added fat; series E and F contained 10% added feed grade stabilized animal tallow and corn oil,
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
A E F G H I
Choline level mg/lb.
274
G.
F.
COMBS AND N.
HELBACKA
TABLE 3.—Amount of high rat ration selected, as percent of total feed consumed.1 (Exp. IB) C / P ratio
All-plant rations Control rations
55:1
58:1
62:1
66:1
Av.
92 88
96 97
90 83
84 88
90 89
1 Choice of feeds containing 0 and 9% hydrolyzed animal and vegetable fat. Each value based on results of one lot of 16 hens.
fat mash selected ranged from 84 to 90% of the total feed consumed. There is no suggestion that either level of protein or presence of animal protein supplements in the ration materially affected the proportion of high fat ration selected. In Experiment IC, where feeds differing in protein level were offered free-choice, the Calorie/protein ratio of the total feed consumed ranged from 59.0-62.1:1 with allplant rations and 56.6-59.0:1 with rations containing crab meal and meat scraps (Table 4). The average C/P ratios selected for all 8 groups was 59.6:1. It is of particular interest to note that the self selection of protein level by these hens resulted in a greater consumption of protein in relation to energy than appeared to be necessary according to results obtained with rations containing lower levels of protein in Experiment 1A and IB. A summary of the results obtained in Experiment 1 (1A, IB, and IC) is given in Table 5. For ease of presentation, the results of Experiments 1A, IB, and IC have been combined in the comparison involving all-plant versus animal protein supplemented rations. Also, the results of Experiments 1A and IC have been combined to give a total of 12 groups of hens receiving
RESULTS AND DISCUSSION
Experiment 1. The results of Experiment IB which permitted free-choice consumption of rations differing primarily in fat content, showed a marked and consistent preference for those feeds which contained 9% added fat (Table 3). The amount of high
TABLE 4.—Average C/P ratio selected1 (Exp. IC)
All-plant rations Control rations
No added fat
9% added fat
Av.
59.0,62.1 59.0,58.9
60.6,61.7 58.5,56.6
60.9 58.3
1 Choice of rations with Calorie/protein rates of either 55:1 or 66:1. Each value based on results of a group of 16 hens.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
respectively. Rations Series G, H, and I differed from ration Series A, E, and F, respectively, only in that they contained 48 ppm. of supplemental zinc supplied as zinc chloride. Ration Series J and K differed from ration Series H and I in that they contained 200 milligrams of added choline (as chloride) per pound of ration. Ration Series E and F were calculated to contain approximately 600 mg. of choline per pound. For the first 16 weeks of the 32-week experimental period, four different rations, varying in C/P ratio within each ration series, were fed to single pens of 24 pullets. Since the actual protein levels (N X 6.25) were found to be appreciably higher than the calculated protein levels and no differences due to protein level were observed, only the highest and lowest protein level feeds within each lettered ration series were fed during the last 16 weeks of the experiment. In all cases, those pens which had received the next to highest protein level in each series were changed to the highest protein level, and those which had been fed the next to lowest protein level were changed to the lowest protein feed. During the last six weeks of the experiment, those pens which had been shifted from one protein level to another at the end of the 16th week, received 1.5% ammonium chloride as a further supplement in their ration. This was prompted by the results of other work then in progress. The same observations made in this experiment were made in Experiment 1. In addition, yolk weights were determined at the end of the 16 weeks.
V.
275
LAYING RATIONS TABLE 5.—Summary of results obtained in Exp. 1. {24 wks.) Added fat le:vel
T y p e of ration Observations
All-plant control 1 (16)2
9%
8%*
(16)
(12)
(12)
(8)
52.9 67.0 105 6.50 3.67 828 62.1 11.7 14.8 14.0 78.5 14.6
54.0 65.7 50 6.43 3.70 776 58.3 12.3 13.2 14.1 79.3 15.1
52.4 67.5 128 6.28 3.51 819 62.6 11.3 12.3 14.0 78.9 14.2
54.7 67.9 169 6.54 3.64 840 62.6 11.7 11.0 14.2 78.9 14.3
53.1 67.3 139 6.56 3.71 807 66.5 12.1 12.6 14.1 77.9 14.6
52.4 66.8 102 6.26 3.51 790 61.6 11.3 12.7 14.3 79.2 14.4
50.9 66.1 98 6.57 3.94 848 61.6 11.9 8.6 14.2 79.2 14.1
56.9 66.9 126 6.12 3.46 795 55.0 11.6 14.6 14.0 79.0 14.7
54.4 67.4 86 6.46 3.62 802 61.4 11.8 13.0 13.9 79.7 15.0
4.7 10.1 22.2 28.8
4.4 12.0 21.3 28.3
7.8 8.8 22.1 28.7
3.8 10.0
3.9 12.6 21.2 27.9
7.2 9.7 21.5 29.3
6.1 7.9 22.6 28.6
4.5 11.7 21.5 28.3
5.6 9.7
— —
54.655.5:1 (6)
57.958.9:1 (6)
61.362.5:1 (6)
65.266.6:1 (6)
56.662.1:1-1 (8)
— —
1 2 3
Control rations contained 3-5% meat and bone scraps and 1.5-3% crab meal as animal protein supplements. Numbers in parentheses refer to number of lots of 16 Single Comb White Leghorn hens involved at start. This fat level determined by free-choice feeding of feeds containing 0 and 9% added hydrolyzed animal and vegetable fat (See Table 4). * This range of C/P ratios based on results of free-choice consumption of two feeds with C/P ratios of approximate'y 55 and 66, respectively (see5 Table 5). Based on analysis of composite samples of 12 egg yolks collected from each of the 16 lots used in Exp. 1A during the 22nd week.
feeds containing either 0 or 9% added fat. The data from hens (Experiment IB) which consumed a free-choice mixture of feeds containing an average of 8% added fat are given separately. For the comparisons of feeds with different Calorie/protein ratios, the results of Experiment 1A and IB were combined. The results obtained in Experiment 1C, where the hens selected their own C/P ratio, also are given separately. In Experiment 1, none of the dietary treatments was found to affect egg production, mortality, Haugh units, shell thickness, egg inclusions, or cholesterol and fat content of the yolk. The addition of animal protein to the ration also failed to show any advantage in performance. Hens receiving the high fat diets consumed slightly more energy and protein per 100 grams of eggs laid than did the controls receiving low fat rations. Consistent with this is the increase in body weight gains made by the hens fed rations containing high levels of fat during the study. Furthermore, eggs from hens fed the high fat rations were found to be significantly heavier than those from controls consuming the low fat feeds. There was no increase in
calcium consumption or decrease in egg shell thickness as a result of additional fat. No apparent difference in mortality rate directly due to fat level in the diet was observed. Consistent differences were not noted in comparing the hens fed the various series of rations containing different Calorie/ protein ratios except for the slight reduction in protein consumed per 100 grams of eggs by the hens fed the wider C/P ratio rations. There was no apparent effect on egg production, egg weight, body weight, or energy consumed per 100 grams of eggs laid. The Calorie/protein ratios based on protein determinations (N X 6.25) ranged from 54.6-66.6:1, while those estimated by calculation ranged from 56-73:1. This difference in calculated and actual protein content (Table 1) illustrates the need for nitrogen determinations where practical ingredients are involved. Experiment 2. The results obtained in Experiment 2 with respect to effect of C/P ratio and fat level in the ration agree well with those obtained in Experiment 1 (see Table 6). Hens receiving added fat in their ration consumed slightly more energy and
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Egg production, % 54.2 Egg weight, gms. 66.9 Body weight gain, gms. 112 Lbs. feed/doz. eggs 6.30 Lbs. feed/lb. eggs 3.57 Cal. prod, energy/100 gms. egg 787 Gms. crude protein/100 gms. egg 58.1 Gms. calcium/100 gms. egg 11.8 Mortality, % 9.9 14.2 Shell thickness (.001') Haugh units 79.6 14.5 Yolk color score Egg inclusions Blood spots, % 5.5 M e a t spots, % 10.5 5 21.2 Cholesterol, mg./gm. yolk 5 Yolk fat, % (wet basis) 28.3
Calorie/protein ratios
none
276
G.
F.
COMBS AND N.
V.
HELBACKA
TABLE 6.—Summary of results obtained in exp. 2. (32 wks.) Supplemental
Choline level
Zinc
mg / l b .
Added fat level Observations None
10% Tallow
10% corn oil
Calorie/Pr 48.4- 52.5:1 None 48 ppm.
600
(8)»
(8) (8)>
(8)
59.5 57.0 58.9 64.0 65.2 66.1 132 213 172 5.99 6.11 5.77 3.54 3.54 3.30 831 733 795 59.8 64.8 60.4 11.2 11.8 10.7 11.6 8.9 17.2 14.3 14.2 14.4 77.0 77.7 76.0 29.2 29.0 32.2 33.4 33.1 33.0 18.2 17.8 18.3
(12)
(12)
(8)
59.5 57.4 65.2 65.1 168 172 5.90 5.99 3.42 3.48 772 784 61.0 62.0 11.2 11.2 12.6 12.6 14.3 14.2 77.1 76.5 30.8 30.2 32.8 33.5 18.1 18.1
55.5 57.5 65.7 65.6 182 159 6.15 6.07 3.54 3.50 831 821 64.8 64.0 11.4 11.3 13.6 14.1 14.2 14.2 76.6 75.6
— —
18.0
(8)3
(8)
(8)
— —
17.7
56.3 57.1 65.1 65.2 154 177 6.11 6.22 3.55 3.61 786 815 69.4 68.6 11.6 11.8 12.1 11.6 14.3 14.2 76.8 77.0 30.3 33.1 18.1 18.1
— —
60.5 59.1 65.6 65.6 163 172 5.80 5.77 3.34 3.33 769 779 56.5 54.4 10.7 10.7 12.1 15.1 14.0 14.5 76.2 76.1 — 30.0 — 33.1 17.7 17.9
1 2 3 4
Numbers in parentheses refer to number of lots of 25 SCW Leghorn hens involved at start. During the first 16 weeks, these hens received rations with C/P ratios of 53.0-56.3:1. During the first 16 weeks, these hens received rations with C/P ratios of 58.4-60.4:1. Based on composite samples of 16 eggs collected from each group of hens fed the rations in Series A, E, F, G, H and I during the 28th week. 8 Based on approximately 40 eggs yolks per group collected during the 24th week of the experiment.
protein per 100 grams of eggs laid, and gained more in body weight during the trial. Egg weight again was found to be significantly higher with the addition of either corn oil or tallow. With feeds of similar composition as used in Trial 1, the C/P ratios again were somewhat narrower (based on protein determination) than had been calculated. Again, no differences in the results can be ascribed to effect of energyprotein balance. Results of these two trials indicate that C/P ratios as wide as 65 or 66:1 were adequate for Single Comb White Leghorns to support egg production of approximately 60%. The addition of choline in this study failed to improve any of the test criteria. Since choline was added to the rations containing 10% added fat, these results indicate that 600 mgs. of choline was adequate even for this fat level. A summary of the effect of fat level on egg weight at 8-week intervals within each of the experiments is given in Table 7. These differences were found to be significant for each of the fats in both experiments at the 1% level. The cholesterol content per gram of egg
yolk was increased by 10% on the average when 10% corn oil was added to the ration (Tables 8 and 9). This difference was statistically significant at the 1% level. The addition of 10% tallow, however, resulted in no change in yolk cholesterol level. The amount of lipids per gram of egg yolk was not increased by feeding 10% of either corn oil or tallow. This increase in egg yolk cholesterol per gram of yolk fat is in agreeT A B L E 7.—Fat level and et W e e k s on diet
Av. egg weight (gms.) 1
8 16 24
66.4 65.9 64.8
% H?d/ an: & veg. jat series 67.3 67.2 66.2
Av.
65.7
66.9
Experiment
1 No added fat series J
Experiment 2 8 16 24 32 Av. 1
No added fat series 64.0 63.5 64.2 64.1 64.0
P
10% tallow series 64.5 64.8 65.9 65.5 65.2**
10% com oil series 64.5 66.4 66.5 67.0 66.1**
Each value based on from 120 to 240 eggs collected during a 3-day period from 8 pens of hens being fed the specified fat level. ** Significant at the 1% level.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Egg production, % Egg weight, gms. Body weight, gain, gms. Lbs. feed/doz, eggs Lbs. feed/lb. eggs Cal. prod, energy/100 gms. egg Gms. crude protein/100 gms. egg Gms. calcium/100 gm. egg Mortality, % Shell thickness (.001 in.) Haugh units 4 Cholesterol, m g . / g m . yolk 5 Yolk fat, % (wet basis) Yolk wt., gms.
(8)
64.6-65.2:1
800
277
LAYING RATIONS TABLE 8.—Effect of added fat, zinc and C/P ratio on levels of egg yolk cholesterol and lipids
Added fat
C/P ratio 51:1
C/Pratio65:l
Added zinc
Added zinc
+
-
+
mg. cholesterol/'gm. yolk {wet basis) none 29.4 29.0 28.3 30.1 10% Tallow 29.2 27.8 31.9 27,2 10% Corn oil 33.5 32.9 30.1 32.2 lipids in 33.0 32.7 32.0
Egg weight
Haugh units
Shell thickness 1
Period
:
1
% none 10%Tallow 10% Corn oil
TABLE 10.—The eject of 1.5% NH&l on egg quality {Experiment 2)
26th week (prior to treatment) 28th week 30th week 32nd week
Con- 1.5% Con- 1.5% trol NH 4 C1 trol NH4CI
Con- 1.5% trol NH4CI
65.4 66.2 65.6 65.6
14.5 13.9 13.9 13.8
66.1 66.0 65.4 65.7
77.4 76.0 75.0 74.4
77.5 77.0 76.7 75.0
14.6 12.9 12.9 12.9
1 Inches X 1,000.
1
yolk (wet basis) 34.1 33.9 33.1 32.5 33.4 32.9
32.7 34.0 33.7
SUMMARY
Two experiments, each involving 32 pens of Single Comb White Leghorns, were conment with the results of Fisher and Leveille ducted for 24 and 32 weeks, respectively. (1957). Rations were fed ranging from 14.6 to Except for a slight increase in percent of 19.1% protein and 909 to 1,096 Calories of lipids in egg yolk (Table 6), the addition productive energy per pound with C/P of zinc also failed to measurably influence ratios of from 54.6:1 to 66.6:1. The results the results. Although the yolk lipids were revealed that a C/P ratio as wide as 66:1 increased only slightly (Tables 8 and 9), the was adequate to support 60% egg produceffect was very consistent, and proved to be tion. Layers permitted free-choice selection significant at the 1% level. The explanation of feeds varying in protein level, selected for this apparent effect is unknown. rations with C/P ratios ranging from 56.6The addition of 1.5% NH4C1 to the diet 62.1:1 with an average of 59.6:1. did not have any adverse effects on egg proThe addition of either 9% hydrolyzed duction. There appeared to be a slight imanimal and vegetable fat, 10% animal talprovement in albumen quality but it is below, or 10% corn oil significantly increased lieved that 2% NH4C1 is necessary to show egg size, but had little effect on other test marked improvement (Hall and Helbacka, criteria. Corn oil supplementation did increase the cholesterol per gram of yolk. TABLE 9.—Analysis of variance for egg yolk choles- Layers permitted free-choice selection of terol and lipids as influenced by added fat, feeds varying in fat content consistently sezinc and Calorie/protein ratio lected a ration which contained approxiYolk cholesterol Yolk lipids mately 8% added fat. Source of variation d.f. Mean Mean F F Additional choline supplementation to Squares Squares 2 Fat 50.6 26.6** practical rations containing 10% added fat 80. 3.6* C / P ratio 1 1.5 0.8 50. 2.3 and approximately 600 mgs. of choline per Zinc 1 3 7 1.9 515. 23.3** F a t X C / P ratio 2 5.0* 9.5 72. 3.2 pound was without effect. Zinc supplemenFatXZinc 2 19.3 167. 7.6** 10.1** C / P ratio XZinc 1 .9 90. 4.1 0.5 tation was without benefit, except for a F a t XZinc X C / P ratio 2 11.4 283. 12.8** 6.0** Error 36 1.9 22. slight but significant increase in egg yolk 47 Total lipids. ** Significant at 1% level. The addition of 1.5% ammonium chlo* Significant at 5% level.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
1 Each value based on four assays of 3 egg yolks each.
1959). However, even with this level of NH4CI, there is a marked thinning of shells (Table 10).
278
G. F. COMBS AND N. V. HELBACKA
ride did not adversely affect egg production during a 6-week period, but did reduce egg shell thickness. ACKNOWLEDGMENTS
REFERENCES Adams, R. L., B. A. Krautmann, S. M. Hauge, E. T. Mertz and C. W. Carrick, 1958. Protein levels for layers as influenced by vitamin additions. Poultry Sci. 37 : 1180. Berg, L. R., and G. E. Bearse, 1956. The effect of water-soluble vitamins and energy level of the diet on the performance of laying pullets. Poultry Sci. 35: 945-951. Berg, L. R., and G. E. Bearse, 1957. The effect of protein and energy content of the diet on the performance of laying hens. Poultry Sci. 36: 1105. Clark, T. B., T. D. Runnels, J. H. Reitz and C. E. Weakley, Jr., 1942. Egg production and mortality of White Leghorns fed high and low protein rations. Poultry Sci. 2 1 : 468. Fisher, H., and G. A. Leveille, 1957. Observations on cholesterol, linoleic and linolenic acid content of eggs as influenced by dietary fats. J. Nutrition, 63: 119-129. Fraps, G. S., 1946. Composition and productive
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
This investigation was supported in part by a grant from the Fox Company, Newfield, New Jersey. The authors are especially indebted to Mr. Jerome Rank for caring for the birds, and Mr. Paul Harris for assistance in statistical analysis and for performing some of the yolk cholesterol and fat assays. We are also indebted to Merck & Company, Inc., Rahway, New Jersey, for supplying antibiotics and crystalline vitamins; Nopco Chemical Company, Harrison, New Jersey, for vitamin A and D supplements; Commercial Solvents Corporation, New York, New York, for Bacitracin; The Crab Meal Research Association, Philadelphia, Pennsylvania, for crab meal: Limecrest Research Laboratory, Newton, New Jersey, for trace minerals, and E. F. Drew & Company, Inc., New York, New York, for corn oil used in this study.
energy of poultry feeds and rations. Texas Agr. Exp. Sta. Bulletin 678. Graham, J. C , 1934. Individuality of pullets in balancing the ration. Poultry Sci. 13: 34-39. Hall, K. N., and N. V. Helbacka, 1959. Improving albumen quality. Poultry Sci. 38: 111-114. Helbacka, N. V., and K. N. Hall, 1958. Characteristics of albumen and shell quality of eggs from layers fed NH4C1 in the diet. Poultry Sci. 37: 1211. Heuser, G. F., 1941. Protein in poultry nutrition —a review. Poultry Sci. 20: 362-368. Heywang, B. W., H. R. Bird and M. C. Vavich, 1955. The level of protein in the diet of laying White Leghorns during hot weather. Poultry Sci. 34: 148-152. Hill, F. W., D. L. Anderson and L. M. Dansky, 1956. Studies of the energy requirements of chickens. Poultry Sci. 35: 54-59. Hochreich, H. J., C. R. Douglas and R. H. Harms, 1957. The effect of dietary energy and protein levels upon production of Single Comb White Leghorn hens. Poultry Sci. 36: 1127. Ingram, G. R., 1956. How varied laying conditions affect protein requirements. Flour and Feed, March: 4. Jensen, L. S., J. B. Allred, R. E. Fry and J. McGinnis, 1957. Studies on an unidentified factor necessary for maximum egg weight. Poultry Sci. 36: 1130. Lillie, R. J., J. R. Sizemore, J. L. Milligan and H. R. Bird, 1952. Thyro-protein and fat in laying diets. Poultry Sci. 3 1 : 1037-1042. MacDonald, A. J., 1938. The protein requirement of laying birds. Agric. Progress, 15: 101-110. Maclntyre, T. M., 1958. The effect of low levels of protein on the performance of laying hens fed rations of varying energy content. Poultry Sci. 37: 1223. McDaniel, A. H., J. H. Quisenberry, B. L. Reid and J. R. Couch, 1959. The effect of dietary fat, caloric intake and protein level on caged layers. Poultry Sci. 38: 213-219. Miller, E. C , M. L. Sunde and C. A. Elvehjem, 1957. Minimum protein requirement of laying pullets at different energy levels. Poultry Sci. 36: 681-690. Milton, J. E., and G. R. Ingram, 1957. The protein requirement of laying hens as affected by temperature, age, breed, system of management and rate of lay. Poultry Sci. 36: 11411142. Reid, B. L., J. H. Quisenberry and J. R. Couch, 1951. Aureomycin, vitamin Bi2, methionine and
LAYING RATIONS level of protein in mature fowl nutrition. Poultry Sci. 30: 935. Sherwood, D. H., 1958. Factors affecting egg quality—a review. Poultry Sci. 37: 924-932. Thornton, P. A., R. E. Moreng, L. G. Blaylock and T. S. Hartung, 1956. The effects of dietary protein level on egg production, egg size, egg quality and feed efficiency. Poultry Sci. 35: 1177. Thornton, P. A., L. G. Blaylock and R. E. Moreng, 1957. Protein level as a factor in egg production. Poultry Sci. 36: 552-557. Thornton, P. A., and R. E. Moreng, 1958. The effect of ascorbic acid in the diet of the laying
279
hen. Poultry Sci. 37: 1248. Thornton, P. A., and R. E. Moreng, 1959. Further evidence in the value of ascorbic acid for maintenance of shell quality in warm environmental temperature. Poultry Sci. 38: 594-599. Titus, H. W., 1958. Address at Eleventh Annual California Animal Industry Conf. Wiese, A. C , C. F. Petesron and G. J. Anderson, 1957. Influence of energy and vitamin supplementation on egg production and shell quality. Poultry Sci. 36: 1168. Zlatkis, A., B. Zak and A. J. Boyle, 1953. A new method for the direct determination of serum cholesterol. J. Lab. Clinical Med. 4 1 : 486-492.
B. E. MARCH AND JACOB BIELY Poultry Nutrition Laboratory, The University of British Columbia, Vancouver, B.C. (Received for publication June 29, 1959)
D
ONALDSON et al. (1957) showed that growing chicks can tolerate as much as 33% of fat in the diet provided the other nutrients are supplied in adequate amounts. The quantity of fat which can be incorporated into a ration would appear to be, therefore, limited more by the physical characteristics of the resulting feed than by the tolerance of the bird for fat. Shoshkes et al. (1951) found that fat emulsions might be administered orally to promote a high caloric intake in human nutrition. The following experiments were conducted to determine if growing chicks would drink an aqueous emulsion of oil and what effect the consumption of such an emulsion would have on growth and feed efficiency. EXPERIMENTAL AND RESULTS Experiment 1. Two standardized lots of 3^2 week old New Hampshire cockerels were fed a basal diet containing 27.5% protein and given water or an aqueous emul* Supported by a grant from the National Research Council (Canada).
sion of corn oil respectively. The composition of the diet was as follows: ground wheat, 30.43; ground yellow corn, 22.92; soybean oil meal (44% protein), 26; herring meal (70% protein), 12; dried brewers' yeast, 2.5; dehydrated cereal grass, 2.5; limestone, 1.0; bone meal, 1.5; iodized salt, 0.5; choline chloride (25%), 0.4; manganese sulphate, 0.025; DL-methionine, 0.25 lbs. per 100 lb.; riboflavin, 0.1; calcium pantothenate, 0.4; niacin, 0.8; folacin, 0.02 gm. per 100 lbs.; vitamin A, 200,000 I.U.; vitamin D 3 , 12,000 I.C.U. per 100 lbs. The emulsion was made to contain 10% by volume of corn oil and was stabilized with 0.5% lecithin and 0.1% cellulose gum.1 The preparation was made up as required using a Waring Blendor. The average weight of the chicks in both lots at the beginning of the experiment was 331 grams. The chicks were subsequently weighed after being on the experiment for 1, 2, and 4 1
Hercules CMC-Low, Hercules Powder Co., Inc. Courtesy Harrisons Crosfield (Canada) Ltd.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Emulsified Oil as a Liquid Feed Supplement for Poultry*
Poultry Department, University of Maryland, College Park, Maryland (Received for publication June 25, 1959)
T
271
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
eluded that 15% protein was adequate during moderate to hot weather. Lillie et al. (1952) observed an improvement in efficiency of egg production as measured by feed requirement when 8% lard was included in the ration. Hill et al. (1956) found that rations containing up to 10% tallow were utilized satisfactorily by layers with less feed required per dozen eggs. On the other hand, McDaniel et al. (1959) observed a high incidence of fatty livers and excessive abdominal fat deposits in caged layers fed high energy diets containing added fat. Sherwood (1958) has recently reviewed nutritional factors which influence egg quality. Berg and Bearse (1956) found significantly higher Haugh unit scores for eggs when hens were fed low energy feeds. Recently, Helbacka and Hall (1958) also reported an increase in Haugh units of eggs from hens fed ammonium chloride. Although egg size is largely determined by heredity and body size, feed can influence it to some extent. Jensen et al. (1957) reported an unidentified factor in yellow corn and corn oil that increased egg size. Others have found an initial depression in egg size when low energy or low protein feeds were used (Thornton et al., 1956; Miller et al, 1957; Berg and Bearse, 1957). Thornton and Moreng (1958, 1959) recently published a report showing that vitamin C was necessary to maintain shell thickness during high environmental temperatures. Titus (1958) improved shell 1 Scientific Article No. A 776, Contribution No. thickness by feeding high calcium levels, 3038 of the Maryland Agricultural Experiment and Wiese et al. (1957) demonstrated a Station (Department of Poultry Husbandry).
HE PROTEIN requirement of laying hens has been studied by many, and widely different apparent results have been obtained. The minimum protein level needed by laying hens, expressed as percent of ration, has been found to be from 12 to 14% by Graham (1934), MacDonald (1938), Miller et al. (1957), Thornton et al. (1957), Adams et al. (1958), and MacIntyre (1958); 16% by Heuser (1941); and from 17 to 18% by Reid et al. (1951), Ingram (1956), and Hochreich et al. (1957). Hill et al. (1956) found that 15% protein was adequate for 5 lb. Leghorns while up to 16.5% protein was needed for 4 lb. Leghorns maintained in heated pens. A protein-energy relationship affecting egg production was observed by Hochreich etal. (1957) and Berg and Bearse (1957). Hens fed a low energy, 14% protein ration supported a rate of lay comparable to that of hens fed a high energy ration containing 18% protein. Milton and Ingram (1957) also observed that older birds needed higher protein levels than pullets. Moreover, Clark et al. (1942) observed that hens fed a high protein containing ration during either the growing or laying period produced more eggs than did controls fed low protein rations through both periods. Milton and Ingram (1957) reported that layers at ambient temperatures of 70°F. to 90°F. needed a higher protein level (18%). Previously, Heywang et al. (1955) had con-
272
G. F. COMBS AND N. V. HELBACKA TABLE 1.—Composition of hen rations Ration designation Ingredient
Ground yellow corn Stabilized fat1 Soybean oil meal, 44% protein Crab meal, 30% protein Meat and bone scrap, 50% prot. Dhy. alfalfa meal, 17% protein (1000,000 IU vit. A/lb.) Limestone, ground Dicalcium phosphate (18% P, 26% Ca) Salt Trace mineral mix2 Choline chloride, 25% mix Vitamin A sup. (2,500 IU/gm.) Vitamin B123 sup. (3 mg./lb.) Special mix Nutrient Content Productive energy,4 Cal./lb. Crude protein, %, as calc. Crude prot. as deter. (Exp. 1) Crude prot. as deter. (Exp. 2) Crude fat, %, as calc. Crude fat, %, as deter. (Exp. 1) C/P ratios (Exp. 1) C/P ratio' (Exp. 2)
A-4
B-1
B-4
C-1
C-4
lbs. per Ion 1,002.0 1,205.5 180.0 180.0 605.0 605.0
D-l
D-4
1,031.7 180.0 480.0 50.0 100.0
1,224.5 180.0 340.0 30.0 60.0
982.0 200.0 605.0
1,185.5 200.0 415.0
E-l &F-1 E-4&F-4
1,355.0
1,528.5
1,381.7
1,549.5
— 440.0
— 280.0
— —
— —
— 320.0 50.0 100.0
— 200.0 30.0 60.0
— —
— —
— —
— —
50.0 90.0
30.0 93.0
50.0 60.0
30.0 75.0
50.0 93.0
30.0 96.0
50.0 65.0
30.0 75.0
50.0 93.0
30.0 96.0
45.0
45.0
20.0
33.0
50.0
50.0
25.0
38.0
50.0
50.0
8.0 1.5 1.5 2.5
2.35 4.15
8.0 1.5 3.5 4.0
2.35 4.15
2,000.0 2,000.0
8.0 1.5 1.5 2.5
0.65 4.15
8.0 1.5 3.5 4.0
1.35 4.15
8.0 1.5 1.5 2.5
2.35 4.15
8.0 1.5 3.5 4.0
2.35 4.15
8.0 1.5 1.5 2.5
0.65 4.15
8.0 1.5 3.5 4.0
1.35 4.15
8.0 1.5 1.5 2.5
2.35 4.15
8.0 1.5 3.5 4.0
2.35 4.15
2,000.0 2,000.0
2,000.0
2,000.0
2,000.0
2,000.0 2,000.0
2,000.0
909.0 16.4 16.4 18.8
968.0 13.3 14.6 15.0
944.0 17.0 17.0
985.0 13.5 14.8
1,019.0 18.6 18.6
1,075.0 14.9 16.4
1,043.0 19.1 19.1
1,096.0 15.3 16.8
1,037.0 18.5
1,093.0 14.8
— 3.5
— 3.5
— 11.9
13.3
55.4 48.4
66.3 64.6
55.5
66.6
11.3 54.8
— 11.9
— 16.8
3.8
— 11.6
— 19.8
3.7
— 12.3
—
—
—
— — 53.5
— — 65.2
2.9 3.3
3.2 3.3
11.6 65.5
—
12.8 54.6
—
10.3 65.2
—
12.6
1 2 3
Hydrolyzed animal and vegetable fat (Proctor & Gamble) in C&D ration series; corn oil in E series; and tallow in F series. Contained 6% manganese, 12% iodine, 2% iron, 0.2% copper, .006% zinc, 0.02% cobalt, and 27% calcium. Supplied per ton (gms.): riboflavin, 2; Ca pantothenate, 5; niacin, 18; choline chloride, 20; procaine penicillin, 3.75; streptomycin sulfate,4 11.25; zinc bacitracin, 5; and 510 I.C.XJ. of vitamin Ds per lb. Fraps (1946) productive energy values used, except that a value of 2900 Calories per lb. was used for fat. 6 Based on protein assay values (NX6.25).
negative relationship between dietary energy and shell thickness. The following studies were initiated to determine the effects of different nutritional variables on egg quality and performance of laying hens. EXPERIMENTAL PROCEDURE Experiment 1. The first experiment involved 32 pens of sixteen lOJ^-month old Single Comb White Leghorn hens (Mt. Hope). These hens had come into production in August but were maintained on range until December since facilities for housing were not then available. During the 24-week experimental period, they were maintained in floor pens with litter in an unheated, open-front type house and provided continuous light. Water, calcite grit, and all-mash experimental rations were supplied ad libitum. The composition of 8 of the 16 rations used in this experiment is given in Table 1
together with their C/P ratios, energy, protein, and fat content. In addition, 8 other rations were used which were obtained by blending certain of the feeds shown in Table 1. For example, ration A2 consisted of 2 parts of ration Al blended with 1 part of ration A4. Similarly, ration A3 was prepared by blending 2 parts of ration A4 and 1 part of ration Al. In this way, rations containing different Calorie/protein ratios ranging from 54.6:1 to 66.6:1 were obtained with energy levels ranging from 909 Calories to 1,096 Calories of productive energy per pound and protein levels ranging from 14.6 to 19.1% (N X 6.25). Eight of the rations fed contained 9% added fat (hydrolyzed animal and vegetable fat) while the other half contained no added fat. Series A and C rations contained no animal protein supplements while Series B and D rations contained 1.5-2.5% crab meal and 3-5% meat and bone scrap. This experiment was divided into three
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Total lbs.
A-1
273
LAYING RATIONS TABLE 2.--Ration
designation and variables used
Experiment 1A Ration Series
Added fat % (Hyd. An. & Veg. Fat)
Animal Protein
0 0 9 9
_
A B C D
Calorie/Protein Ratio 1 54.6-55.5:1
57.9-58.9:1
A-1 B-1 C-1 D-1
A-2 B-2 C-2 D-2
+ +
61.3-62.5:1 A-3 B-3 C-3 D-3
65.2-66.6:1 A-4 B-4 C-4 D-4
Experiment 2 Ration series
J
K 1
Added
added fat, %
(Calorie/Protein Ratio 1
ppm
Tallow Corn oil
48.4-52.5:1 53.0-56.3:1 58.4-60.4: 1 64.6-65.2:1
530 600 600 530 600 600 800 800
— — —
48 48 48 48 48
— 10
— — 10
— 10
—
— — 10 — — 10
A-1 E-l F-l G-l H-l 1-1
A-2 E-2 F-2 G-2 H-2 1-2
-
J-l
J-2
10
K-l
K-2
A-3 E-3 F-3 G-3 H-3 1-3 J-3 K-3
A-4 E-4 F-4 G-4 H-4 1-4
J-4
K-4
Protein level based on NX 6.25.
parts, designated 1A, IB, and IC. The experimental design and rations used in Experiment 1A are given in Table 2. This experiment consisted of 2 related 8-pen factorials in series. Each of these series involved protein level, fat level, and presence or absence of animal protein as variables. Part 2 (Experiment IB) consisted of 8 pens, each of which had free choice of either of two feeds. The combinations were Al and CI, A2 and C2, A3 and C3, A4 and C4, Bl and Dl, B2 and D2, B3 and D3, B4 and D4. Thus, the hens in each pen were able to select their level of fat by varying their consumption of the high and low fat rations. In Experiment IC, 8 pens of hens were permitted free choice consumption of two rations having the widest and narrowest C/P ratios in each ration series, respectively. For example, two replicated groups were each supplied rations Al and A4; two others, Bl and B4; two others, CI and C4; and the last two, Dl and D4. These groups were able to determine their own level of
protein intake and the C/P ratio of the total feed consumed. Daily records of egg production and mortality were kept on a pen basis. In addition, feed consumption and body weight were recorded at 8-week intervals. Measurements were made on egg weight, egg shell thickness, Haugh units, yolk color, and egg inclusions from the last three days' collection of eggs of each 8-week period. In addition, yolk cholesterol and yolk fat contents were determined from eggs collected during the 24th week from each of the 16 pens included in Experiment 1A. Cholesterol was analyzed by a modified method of Zlatkis etal. (1953). Experiment 2. In Experiment 2, 32 pens, each consisting of 24 8J^-month old Single Comb White Leghorn pullets (Mt. Hope), were utilized. The treatments imposed are indicated in Table 2. The composition of ration Series A, E, and F are given in Table 1. Series A rations contained no added fat; series E and F contained 10% added feed grade stabilized animal tallow and corn oil,
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
A E F G H I
Choline level mg/lb.
274
G.
F.
COMBS AND N.
HELBACKA
TABLE 3.—Amount of high rat ration selected, as percent of total feed consumed.1 (Exp. IB) C / P ratio
All-plant rations Control rations
55:1
58:1
62:1
66:1
Av.
92 88
96 97
90 83
84 88
90 89
1 Choice of feeds containing 0 and 9% hydrolyzed animal and vegetable fat. Each value based on results of one lot of 16 hens.
fat mash selected ranged from 84 to 90% of the total feed consumed. There is no suggestion that either level of protein or presence of animal protein supplements in the ration materially affected the proportion of high fat ration selected. In Experiment IC, where feeds differing in protein level were offered free-choice, the Calorie/protein ratio of the total feed consumed ranged from 59.0-62.1:1 with allplant rations and 56.6-59.0:1 with rations containing crab meal and meat scraps (Table 4). The average C/P ratios selected for all 8 groups was 59.6:1. It is of particular interest to note that the self selection of protein level by these hens resulted in a greater consumption of protein in relation to energy than appeared to be necessary according to results obtained with rations containing lower levels of protein in Experiment 1A and IB. A summary of the results obtained in Experiment 1 (1A, IB, and IC) is given in Table 5. For ease of presentation, the results of Experiments 1A, IB, and IC have been combined in the comparison involving all-plant versus animal protein supplemented rations. Also, the results of Experiments 1A and IC have been combined to give a total of 12 groups of hens receiving
RESULTS AND DISCUSSION
Experiment 1. The results of Experiment IB which permitted free-choice consumption of rations differing primarily in fat content, showed a marked and consistent preference for those feeds which contained 9% added fat (Table 3). The amount of high
TABLE 4.—Average C/P ratio selected1 (Exp. IC)
All-plant rations Control rations
No added fat
9% added fat
Av.
59.0,62.1 59.0,58.9
60.6,61.7 58.5,56.6
60.9 58.3
1 Choice of rations with Calorie/protein rates of either 55:1 or 66:1. Each value based on results of a group of 16 hens.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
respectively. Rations Series G, H, and I differed from ration Series A, E, and F, respectively, only in that they contained 48 ppm. of supplemental zinc supplied as zinc chloride. Ration Series J and K differed from ration Series H and I in that they contained 200 milligrams of added choline (as chloride) per pound of ration. Ration Series E and F were calculated to contain approximately 600 mg. of choline per pound. For the first 16 weeks of the 32-week experimental period, four different rations, varying in C/P ratio within each ration series, were fed to single pens of 24 pullets. Since the actual protein levels (N X 6.25) were found to be appreciably higher than the calculated protein levels and no differences due to protein level were observed, only the highest and lowest protein level feeds within each lettered ration series were fed during the last 16 weeks of the experiment. In all cases, those pens which had received the next to highest protein level in each series were changed to the highest protein level, and those which had been fed the next to lowest protein level were changed to the lowest protein feed. During the last six weeks of the experiment, those pens which had been shifted from one protein level to another at the end of the 16th week, received 1.5% ammonium chloride as a further supplement in their ration. This was prompted by the results of other work then in progress. The same observations made in this experiment were made in Experiment 1. In addition, yolk weights were determined at the end of the 16 weeks.
V.
275
LAYING RATIONS TABLE 5.—Summary of results obtained in Exp. 1. {24 wks.) Added fat le:vel
T y p e of ration Observations
All-plant control 1 (16)2
9%
8%*
(16)
(12)
(12)
(8)
52.9 67.0 105 6.50 3.67 828 62.1 11.7 14.8 14.0 78.5 14.6
54.0 65.7 50 6.43 3.70 776 58.3 12.3 13.2 14.1 79.3 15.1
52.4 67.5 128 6.28 3.51 819 62.6 11.3 12.3 14.0 78.9 14.2
54.7 67.9 169 6.54 3.64 840 62.6 11.7 11.0 14.2 78.9 14.3
53.1 67.3 139 6.56 3.71 807 66.5 12.1 12.6 14.1 77.9 14.6
52.4 66.8 102 6.26 3.51 790 61.6 11.3 12.7 14.3 79.2 14.4
50.9 66.1 98 6.57 3.94 848 61.6 11.9 8.6 14.2 79.2 14.1
56.9 66.9 126 6.12 3.46 795 55.0 11.6 14.6 14.0 79.0 14.7
54.4 67.4 86 6.46 3.62 802 61.4 11.8 13.0 13.9 79.7 15.0
4.7 10.1 22.2 28.8
4.4 12.0 21.3 28.3
7.8 8.8 22.1 28.7
3.8 10.0
3.9 12.6 21.2 27.9
7.2 9.7 21.5 29.3
6.1 7.9 22.6 28.6
4.5 11.7 21.5 28.3
5.6 9.7
— —
54.655.5:1 (6)
57.958.9:1 (6)
61.362.5:1 (6)
65.266.6:1 (6)
56.662.1:1-1 (8)
— —
1 2 3
Control rations contained 3-5% meat and bone scraps and 1.5-3% crab meal as animal protein supplements. Numbers in parentheses refer to number of lots of 16 Single Comb White Leghorn hens involved at start. This fat level determined by free-choice feeding of feeds containing 0 and 9% added hydrolyzed animal and vegetable fat (See Table 4). * This range of C/P ratios based on results of free-choice consumption of two feeds with C/P ratios of approximate'y 55 and 66, respectively (see5 Table 5). Based on analysis of composite samples of 12 egg yolks collected from each of the 16 lots used in Exp. 1A during the 22nd week.
feeds containing either 0 or 9% added fat. The data from hens (Experiment IB) which consumed a free-choice mixture of feeds containing an average of 8% added fat are given separately. For the comparisons of feeds with different Calorie/protein ratios, the results of Experiment 1A and IB were combined. The results obtained in Experiment 1C, where the hens selected their own C/P ratio, also are given separately. In Experiment 1, none of the dietary treatments was found to affect egg production, mortality, Haugh units, shell thickness, egg inclusions, or cholesterol and fat content of the yolk. The addition of animal protein to the ration also failed to show any advantage in performance. Hens receiving the high fat diets consumed slightly more energy and protein per 100 grams of eggs laid than did the controls receiving low fat rations. Consistent with this is the increase in body weight gains made by the hens fed rations containing high levels of fat during the study. Furthermore, eggs from hens fed the high fat rations were found to be significantly heavier than those from controls consuming the low fat feeds. There was no increase in
calcium consumption or decrease in egg shell thickness as a result of additional fat. No apparent difference in mortality rate directly due to fat level in the diet was observed. Consistent differences were not noted in comparing the hens fed the various series of rations containing different Calorie/ protein ratios except for the slight reduction in protein consumed per 100 grams of eggs by the hens fed the wider C/P ratio rations. There was no apparent effect on egg production, egg weight, body weight, or energy consumed per 100 grams of eggs laid. The Calorie/protein ratios based on protein determinations (N X 6.25) ranged from 54.6-66.6:1, while those estimated by calculation ranged from 56-73:1. This difference in calculated and actual protein content (Table 1) illustrates the need for nitrogen determinations where practical ingredients are involved. Experiment 2. The results obtained in Experiment 2 with respect to effect of C/P ratio and fat level in the ration agree well with those obtained in Experiment 1 (see Table 6). Hens receiving added fat in their ration consumed slightly more energy and
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Egg production, % 54.2 Egg weight, gms. 66.9 Body weight gain, gms. 112 Lbs. feed/doz. eggs 6.30 Lbs. feed/lb. eggs 3.57 Cal. prod, energy/100 gms. egg 787 Gms. crude protein/100 gms. egg 58.1 Gms. calcium/100 gms. egg 11.8 Mortality, % 9.9 14.2 Shell thickness (.001') Haugh units 79.6 14.5 Yolk color score Egg inclusions Blood spots, % 5.5 M e a t spots, % 10.5 5 21.2 Cholesterol, mg./gm. yolk 5 Yolk fat, % (wet basis) 28.3
Calorie/protein ratios
none
276
G.
F.
COMBS AND N.
V.
HELBACKA
TABLE 6.—Summary of results obtained in exp. 2. (32 wks.) Supplemental
Choline level
Zinc
mg / l b .
Added fat level Observations None
10% Tallow
10% corn oil
Calorie/Pr 48.4- 52.5:1 None 48 ppm.
600
(8)»
(8) (8)>
(8)
59.5 57.0 58.9 64.0 65.2 66.1 132 213 172 5.99 6.11 5.77 3.54 3.54 3.30 831 733 795 59.8 64.8 60.4 11.2 11.8 10.7 11.6 8.9 17.2 14.3 14.2 14.4 77.0 77.7 76.0 29.2 29.0 32.2 33.4 33.1 33.0 18.2 17.8 18.3
(12)
(12)
(8)
59.5 57.4 65.2 65.1 168 172 5.90 5.99 3.42 3.48 772 784 61.0 62.0 11.2 11.2 12.6 12.6 14.3 14.2 77.1 76.5 30.8 30.2 32.8 33.5 18.1 18.1
55.5 57.5 65.7 65.6 182 159 6.15 6.07 3.54 3.50 831 821 64.8 64.0 11.4 11.3 13.6 14.1 14.2 14.2 76.6 75.6
— —
18.0
(8)3
(8)
(8)
— —
17.7
56.3 57.1 65.1 65.2 154 177 6.11 6.22 3.55 3.61 786 815 69.4 68.6 11.6 11.8 12.1 11.6 14.3 14.2 76.8 77.0 30.3 33.1 18.1 18.1
— —
60.5 59.1 65.6 65.6 163 172 5.80 5.77 3.34 3.33 769 779 56.5 54.4 10.7 10.7 12.1 15.1 14.0 14.5 76.2 76.1 — 30.0 — 33.1 17.7 17.9
1 2 3 4
Numbers in parentheses refer to number of lots of 25 SCW Leghorn hens involved at start. During the first 16 weeks, these hens received rations with C/P ratios of 53.0-56.3:1. During the first 16 weeks, these hens received rations with C/P ratios of 58.4-60.4:1. Based on composite samples of 16 eggs collected from each group of hens fed the rations in Series A, E, F, G, H and I during the 28th week. 8 Based on approximately 40 eggs yolks per group collected during the 24th week of the experiment.
protein per 100 grams of eggs laid, and gained more in body weight during the trial. Egg weight again was found to be significantly higher with the addition of either corn oil or tallow. With feeds of similar composition as used in Trial 1, the C/P ratios again were somewhat narrower (based on protein determination) than had been calculated. Again, no differences in the results can be ascribed to effect of energyprotein balance. Results of these two trials indicate that C/P ratios as wide as 65 or 66:1 were adequate for Single Comb White Leghorns to support egg production of approximately 60%. The addition of choline in this study failed to improve any of the test criteria. Since choline was added to the rations containing 10% added fat, these results indicate that 600 mgs. of choline was adequate even for this fat level. A summary of the effect of fat level on egg weight at 8-week intervals within each of the experiments is given in Table 7. These differences were found to be significant for each of the fats in both experiments at the 1% level. The cholesterol content per gram of egg
yolk was increased by 10% on the average when 10% corn oil was added to the ration (Tables 8 and 9). This difference was statistically significant at the 1% level. The addition of 10% tallow, however, resulted in no change in yolk cholesterol level. The amount of lipids per gram of egg yolk was not increased by feeding 10% of either corn oil or tallow. This increase in egg yolk cholesterol per gram of yolk fat is in agreeT A B L E 7.—Fat level and et W e e k s on diet
Av. egg weight (gms.) 1
8 16 24
66.4 65.9 64.8
% H?d/ an: & veg. jat series 67.3 67.2 66.2
Av.
65.7
66.9
Experiment
1 No added fat series J
Experiment 2 8 16 24 32 Av. 1
No added fat series 64.0 63.5 64.2 64.1 64.0
P
10% tallow series 64.5 64.8 65.9 65.5 65.2**
10% com oil series 64.5 66.4 66.5 67.0 66.1**
Each value based on from 120 to 240 eggs collected during a 3-day period from 8 pens of hens being fed the specified fat level. ** Significant at the 1% level.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Egg production, % Egg weight, gms. Body weight, gain, gms. Lbs. feed/doz, eggs Lbs. feed/lb. eggs Cal. prod, energy/100 gms. egg Gms. crude protein/100 gms. egg Gms. calcium/100 gm. egg Mortality, % Shell thickness (.001 in.) Haugh units 4 Cholesterol, m g . / g m . yolk 5 Yolk fat, % (wet basis) Yolk wt., gms.
(8)
64.6-65.2:1
800
277
LAYING RATIONS TABLE 8.—Effect of added fat, zinc and C/P ratio on levels of egg yolk cholesterol and lipids
Added fat
C/P ratio 51:1
C/Pratio65:l
Added zinc
Added zinc
+
-
+
mg. cholesterol/'gm. yolk {wet basis) none 29.4 29.0 28.3 30.1 10% Tallow 29.2 27.8 31.9 27,2 10% Corn oil 33.5 32.9 30.1 32.2 lipids in 33.0 32.7 32.0
Egg weight
Haugh units
Shell thickness 1
Period
:
1
% none 10%Tallow 10% Corn oil
TABLE 10.—The eject of 1.5% NH&l on egg quality {Experiment 2)
26th week (prior to treatment) 28th week 30th week 32nd week
Con- 1.5% Con- 1.5% trol NH 4 C1 trol NH4CI
Con- 1.5% trol NH4CI
65.4 66.2 65.6 65.6
14.5 13.9 13.9 13.8
66.1 66.0 65.4 65.7
77.4 76.0 75.0 74.4
77.5 77.0 76.7 75.0
14.6 12.9 12.9 12.9
1 Inches X 1,000.
1
yolk (wet basis) 34.1 33.9 33.1 32.5 33.4 32.9
32.7 34.0 33.7
SUMMARY
Two experiments, each involving 32 pens of Single Comb White Leghorns, were conment with the results of Fisher and Leveille ducted for 24 and 32 weeks, respectively. (1957). Rations were fed ranging from 14.6 to Except for a slight increase in percent of 19.1% protein and 909 to 1,096 Calories of lipids in egg yolk (Table 6), the addition productive energy per pound with C/P of zinc also failed to measurably influence ratios of from 54.6:1 to 66.6:1. The results the results. Although the yolk lipids were revealed that a C/P ratio as wide as 66:1 increased only slightly (Tables 8 and 9), the was adequate to support 60% egg produceffect was very consistent, and proved to be tion. Layers permitted free-choice selection significant at the 1% level. The explanation of feeds varying in protein level, selected for this apparent effect is unknown. rations with C/P ratios ranging from 56.6The addition of 1.5% NH4C1 to the diet 62.1:1 with an average of 59.6:1. did not have any adverse effects on egg proThe addition of either 9% hydrolyzed duction. There appeared to be a slight imanimal and vegetable fat, 10% animal talprovement in albumen quality but it is below, or 10% corn oil significantly increased lieved that 2% NH4C1 is necessary to show egg size, but had little effect on other test marked improvement (Hall and Helbacka, criteria. Corn oil supplementation did increase the cholesterol per gram of yolk. TABLE 9.—Analysis of variance for egg yolk choles- Layers permitted free-choice selection of terol and lipids as influenced by added fat, feeds varying in fat content consistently sezinc and Calorie/protein ratio lected a ration which contained approxiYolk cholesterol Yolk lipids mately 8% added fat. Source of variation d.f. Mean Mean F F Additional choline supplementation to Squares Squares 2 Fat 50.6 26.6** practical rations containing 10% added fat 80. 3.6* C / P ratio 1 1.5 0.8 50. 2.3 and approximately 600 mgs. of choline per Zinc 1 3 7 1.9 515. 23.3** F a t X C / P ratio 2 5.0* 9.5 72. 3.2 pound was without effect. Zinc supplemenFatXZinc 2 19.3 167. 7.6** 10.1** C / P ratio XZinc 1 .9 90. 4.1 0.5 tation was without benefit, except for a F a t XZinc X C / P ratio 2 11.4 283. 12.8** 6.0** Error 36 1.9 22. slight but significant increase in egg yolk 47 Total lipids. ** Significant at 1% level. The addition of 1.5% ammonium chlo* Significant at 5% level.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
1 Each value based on four assays of 3 egg yolks each.
1959). However, even with this level of NH4CI, there is a marked thinning of shells (Table 10).
278
G. F. COMBS AND N. V. HELBACKA
ride did not adversely affect egg production during a 6-week period, but did reduce egg shell thickness. ACKNOWLEDGMENTS
REFERENCES Adams, R. L., B. A. Krautmann, S. M. Hauge, E. T. Mertz and C. W. Carrick, 1958. Protein levels for layers as influenced by vitamin additions. Poultry Sci. 37 : 1180. Berg, L. R., and G. E. Bearse, 1956. The effect of water-soluble vitamins and energy level of the diet on the performance of laying pullets. Poultry Sci. 35: 945-951. Berg, L. R., and G. E. Bearse, 1957. The effect of protein and energy content of the diet on the performance of laying hens. Poultry Sci. 36: 1105. Clark, T. B., T. D. Runnels, J. H. Reitz and C. E. Weakley, Jr., 1942. Egg production and mortality of White Leghorns fed high and low protein rations. Poultry Sci. 2 1 : 468. Fisher, H., and G. A. Leveille, 1957. Observations on cholesterol, linoleic and linolenic acid content of eggs as influenced by dietary fats. J. Nutrition, 63: 119-129. Fraps, G. S., 1946. Composition and productive
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
This investigation was supported in part by a grant from the Fox Company, Newfield, New Jersey. The authors are especially indebted to Mr. Jerome Rank for caring for the birds, and Mr. Paul Harris for assistance in statistical analysis and for performing some of the yolk cholesterol and fat assays. We are also indebted to Merck & Company, Inc., Rahway, New Jersey, for supplying antibiotics and crystalline vitamins; Nopco Chemical Company, Harrison, New Jersey, for vitamin A and D supplements; Commercial Solvents Corporation, New York, New York, for Bacitracin; The Crab Meal Research Association, Philadelphia, Pennsylvania, for crab meal: Limecrest Research Laboratory, Newton, New Jersey, for trace minerals, and E. F. Drew & Company, Inc., New York, New York, for corn oil used in this study.
energy of poultry feeds and rations. Texas Agr. Exp. Sta. Bulletin 678. Graham, J. C , 1934. Individuality of pullets in balancing the ration. Poultry Sci. 13: 34-39. Hall, K. N., and N. V. Helbacka, 1959. Improving albumen quality. Poultry Sci. 38: 111-114. Helbacka, N. V., and K. N. Hall, 1958. Characteristics of albumen and shell quality of eggs from layers fed NH4C1 in the diet. Poultry Sci. 37: 1211. Heuser, G. F., 1941. Protein in poultry nutrition —a review. Poultry Sci. 20: 362-368. Heywang, B. W., H. R. Bird and M. C. Vavich, 1955. The level of protein in the diet of laying White Leghorns during hot weather. Poultry Sci. 34: 148-152. Hill, F. W., D. L. Anderson and L. M. Dansky, 1956. Studies of the energy requirements of chickens. Poultry Sci. 35: 54-59. Hochreich, H. J., C. R. Douglas and R. H. Harms, 1957. The effect of dietary energy and protein levels upon production of Single Comb White Leghorn hens. Poultry Sci. 36: 1127. Ingram, G. R., 1956. How varied laying conditions affect protein requirements. Flour and Feed, March: 4. Jensen, L. S., J. B. Allred, R. E. Fry and J. McGinnis, 1957. Studies on an unidentified factor necessary for maximum egg weight. Poultry Sci. 36: 1130. Lillie, R. J., J. R. Sizemore, J. L. Milligan and H. R. Bird, 1952. Thyro-protein and fat in laying diets. Poultry Sci. 3 1 : 1037-1042. MacDonald, A. J., 1938. The protein requirement of laying birds. Agric. Progress, 15: 101-110. Maclntyre, T. M., 1958. The effect of low levels of protein on the performance of laying hens fed rations of varying energy content. Poultry Sci. 37: 1223. McDaniel, A. H., J. H. Quisenberry, B. L. Reid and J. R. Couch, 1959. The effect of dietary fat, caloric intake and protein level on caged layers. Poultry Sci. 38: 213-219. Miller, E. C , M. L. Sunde and C. A. Elvehjem, 1957. Minimum protein requirement of laying pullets at different energy levels. Poultry Sci. 36: 681-690. Milton, J. E., and G. R. Ingram, 1957. The protein requirement of laying hens as affected by temperature, age, breed, system of management and rate of lay. Poultry Sci. 36: 11411142. Reid, B. L., J. H. Quisenberry and J. R. Couch, 1951. Aureomycin, vitamin Bi2, methionine and
LAYING RATIONS level of protein in mature fowl nutrition. Poultry Sci. 30: 935. Sherwood, D. H., 1958. Factors affecting egg quality—a review. Poultry Sci. 37: 924-932. Thornton, P. A., R. E. Moreng, L. G. Blaylock and T. S. Hartung, 1956. The effects of dietary protein level on egg production, egg size, egg quality and feed efficiency. Poultry Sci. 35: 1177. Thornton, P. A., L. G. Blaylock and R. E. Moreng, 1957. Protein level as a factor in egg production. Poultry Sci. 36: 552-557. Thornton, P. A., and R. E. Moreng, 1958. The effect of ascorbic acid in the diet of the laying
279
hen. Poultry Sci. 37: 1248. Thornton, P. A., and R. E. Moreng, 1959. Further evidence in the value of ascorbic acid for maintenance of shell quality in warm environmental temperature. Poultry Sci. 38: 594-599. Titus, H. W., 1958. Address at Eleventh Annual California Animal Industry Conf. Wiese, A. C , C. F. Petesron and G. J. Anderson, 1957. Influence of energy and vitamin supplementation on egg production and shell quality. Poultry Sci. 36: 1168. Zlatkis, A., B. Zak and A. J. Boyle, 1953. A new method for the direct determination of serum cholesterol. J. Lab. Clinical Med. 4 1 : 486-492.
B. E. MARCH AND JACOB BIELY Poultry Nutrition Laboratory, The University of British Columbia, Vancouver, B.C. (Received for publication June 29, 1959)
D
ONALDSON et al. (1957) showed that growing chicks can tolerate as much as 33% of fat in the diet provided the other nutrients are supplied in adequate amounts. The quantity of fat which can be incorporated into a ration would appear to be, therefore, limited more by the physical characteristics of the resulting feed than by the tolerance of the bird for fat. Shoshkes et al. (1951) found that fat emulsions might be administered orally to promote a high caloric intake in human nutrition. The following experiments were conducted to determine if growing chicks would drink an aqueous emulsion of oil and what effect the consumption of such an emulsion would have on growth and feed efficiency. EXPERIMENTAL AND RESULTS Experiment 1. Two standardized lots of 3^2 week old New Hampshire cockerels were fed a basal diet containing 27.5% protein and given water or an aqueous emul* Supported by a grant from the National Research Council (Canada).
sion of corn oil respectively. The composition of the diet was as follows: ground wheat, 30.43; ground yellow corn, 22.92; soybean oil meal (44% protein), 26; herring meal (70% protein), 12; dried brewers' yeast, 2.5; dehydrated cereal grass, 2.5; limestone, 1.0; bone meal, 1.5; iodized salt, 0.5; choline chloride (25%), 0.4; manganese sulphate, 0.025; DL-methionine, 0.25 lbs. per 100 lb.; riboflavin, 0.1; calcium pantothenate, 0.4; niacin, 0.8; folacin, 0.02 gm. per 100 lbs.; vitamin A, 200,000 I.U.; vitamin D 3 , 12,000 I.C.U. per 100 lbs. The emulsion was made to contain 10% by volume of corn oil and was stabilized with 0.5% lecithin and 0.1% cellulose gum.1 The preparation was made up as required using a Waring Blendor. The average weight of the chicks in both lots at the beginning of the experiment was 331 grams. The chicks were subsequently weighed after being on the experiment for 1, 2, and 4 1
Hercules CMC-Low, Hercules Powder Co., Inc. Courtesy Harrisons Crosfield (Canada) Ltd.
Downloaded from http://ps.oxfordjournals.org/ by guest on September 10, 2014
Emulsified Oil as a Liquid Feed Supplement for Poultry*