Wild Oat Groats in Broiler Diets

Wild Oat Groats in Broiler Diets K. K. BHARGAVA Quality Feeds Ltd., Lacombe, Alberta TOC ISO F. W. SOSULSKI

Department of Crop Science and Plant Ecology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W0 (Received for publication May 10, 1984) ABSTRACT Wild and domestic oat groats were initially incorporated into starter rations for broiler chicks at 0, 20.5, 41.1, and 61.6% replacement of wheat, soybean, and fish meal. In a subsequent experiment, wild oat groats were fed at 0, 10.0, 20.0, and 30.0% replacement of wheat and soybean meal in starter and grower-finisher rations for broiler chicks. Wild oat groats had no adverse effects on feed efficiency, body, liver, and kidney weights, or on carcass quality up to the 41.1% level, but 61.6% of wild oat groats in the ration caused a significant growth depression in chicks. However, diets containing wild oat flour, and wild oat bran in particular, at the 43.3% replacement level resulted in lower live weights and feed efficiency. It appeared that at least 30% wild oat groats could be incorporated safely into high energy broiler diets and, at this level, a substantial reduction in feed costs was observed. (Key words: wild oat groats, broiler diets, amino acid content, growth) 1986 Poultry Science 65:330-336

INTRODUCTION The eradication of wild oats is a serious agronomic problem in western Canada. It has been estimated that over 200,000 tonnes of wild oat seeds are harvested with the grain crops in each year. Wild oats are separated from other grains in commercial seed cleaning plants associated with flour mills and grain terminals. Preliminary studies on the mechanical dehulling of wild oat screenings obtained from commercial plants showed yields of 50 to 60% of groats, depending on the purity of sample (Sosulski and Sosulski, 1985). These groats contained 20.1% crude protein (N x 6.25), 8.7% oil, and 56.3% starch. Previously, Tkachuk and Mellish (1977) reported that wild oat groats contained 19.6% protein (N x 5.7) but only 1.6% oil. In feeding trials with weanling male rats, the diet which contained only wild oat flakes plus mineral and vitamin supplements gave a protein efficiency ratio of 2.0 (90% of the casein control), and the apparent digestibilities of protein and energy were 87 and 94%, respectively (Sosulski etal, 1985). Because of the high protein and gross energy contents of wild oat groats (WOG), it was of interest to determine their feeding value in broiler rations, specifically as a partial replacement for wheat, fish meal, and soybean meal in

the formulation. Initially, WOG were evaluated in starter diets at 0, 20.5, 41.1, and 61.6% of the ration, and finally at 0, 10.0, 20.0, and 30.0% replacement levels in the starter and grower-finisher diets. MATERIALS AND METHODS Domestic oat groats (DOG) and WOG were processed and supplied by Robin Hood Multifoods Inc., Saskatoon. The proximate compositions of samples of DOG, WOG, wild oat bran (WOB), and wild oat flour (WOF) were determined using standard procedures of the Association of Official Agricultural Chemists 1970). Amino acid analyses were performed using a Beckman amino acid analyzer following hydrolysis with 6 N HCl in sealed evacuated ampules at 100 C for 24 hr. Cysteine and cystine were measured as cysteic acid, and methionine sulfone, after performic acid oxidation and HCl hydrolysis. Tryptophan analysis was performed on a hydrolysate from alkaline hydrolysis with Ba(OH) 2 . A series of three feeding trials were conducted with day-old male Hubbard broiler chicks to evaluate the nutritional value of domestic and wild oat groat products. Four replicates of 10 chicks each were randomly assigned to each treatment in Experiments 1 and 2 and

330

331

WILD OAT GROATS IN DIETS were reared in battery brooders with raised wire floors. In Experiment 3, four replicate pens of 20 chicks each were reared in broiler cages equipped with a solid galvanized iron floor. At the conclusion of each experiment (28 days for Experiments 1 and 2; 49 days for Experiment 3), the live weights, feed conversions, and carcass grades were determined. The diets for Experiment 1 (Table 1) were prepared by replacing the protein equivalent amount of fish meal and wheat in the control diet with either DOG or WOG + DOG. The latter sample contained about 30% of domestic oats in the wild oat sample and is designated as a blend. The rations were kept isocaloric by adjusting the amount of poultry fat and isonitrogenous by altering soybean meal. Methionine and lysine were supplemented to meet the requirements established by the NRC (1977). Experiment 2 was designed to study the effect of feeding graded levels of either WOF or WOB on growth performance of chicks to 28 days. Wild oat flour and WOB were incorporated at either 0, 21.7, or 43.3% levels (Table 2) at the expense of wheat, fish meal, and poultry fat. In addition to these experimental diets, four replicates of 10 chicks each were fed a diet containing 61.6% WOG. Individual blood samples were obtained from the control as well as birds on 61.6% WOG diet by heart

puncture using a heparinized syringe. Approximately 2 to 3 ml of blood were collected from each chick and, following centrifugation, equal amounts of plasma from each chick within the replication were pooled to form the sample for amino acid analysis. The samples were frozen and stored for amino acid analysis following the procedure of Dunkelgod and Winkleman (1982). The diets for Experiment 3 containing 0, 10.0, 20.0, or 30.0% WOG were formulated by linear programming to be isocaloric and isonitrogenous (Table 3). Starter and growerfinisher diets contained .86 and .71% of total sulphur amino acids and 1.25 and 1.0% lysine, respectively, according to the recommendation of the NRC (1977). Starter diets were fed to 28 days and grower-finisher diets to market age. At the termination of Experiment 3, two randomly selected chicks from each replicate were utilized to study the effect of feeding WOG on kidney and liver weights. All experimental diets were fed in mash form. A randomized block design was used for all experiments. The data were analyzed by one-way classification analysis of variance, and treatment mean differences were tested by Duncan's multiple range test (Steel and Torrie, 1960). The responses of weight gain and feed conversion in Experiments 1 and 2 to various

TABLE 1. Percent composition and calculated analysis of starter diets (Experiment 1) Ingredients

1

2

3

4

5

6

7

Ground wheat, 13.9% protein Soybean meal, 46.9% protein Fish meal, 73.0% protein DOG, 1 12.6% protein WOG + DOG, 16.4% protein DL-Methionine L-Lysine hydrochloride Dicalcium phosphate Limestone Iodized salt Vitamin-trace mineral premix 2 Dextrose Poultry fat

61.6 23.0 5.0 0 0 .1 0 1.2 1.4 .3 .3 0 7.4

41.1 25.1 4.0 20.5 0 .1 0 1.3 1.4 .3 .3 0 6.0

20.5 27.2 3.0 41.1 0 .1 .1 1.4 1.4 .3 .3 0 4.7

0 29.3 2.0 61.6 0 .1 0 1.5 1.4 .3 .3 0 3.5

41.0 26.9 1.8 0 20.5 .2 .1 1.5 1.3 .3 .3 0 6.1

22.6 28.0 0 0 41.1 .2 .2 1.7 1.4 .3 .3 0 4.4

0 27.5 0 0 61.6 .2 .2 1.7 1.4 .3 .3 5.0 1.8

Calculated analysis Crude protein, % ME, kcal/g

23.0 3.2

23.0 3.2

23.0 3.2

23.0 3.2

23.0 3.2

23.0 3.2

23.0 3.2

1 2

DOG = Domestic oat groats, WOG = wild oat groats, ME = metabolizable energy. Prairie Microtech, Regina, Saskatchewan; composition of vitamin-trace mineral premix unavailable.

332

BHARGAVA AND SOSULSKI TABLE 2. Percent composition and calculated analysis of starter diets (Experiment 2)

Ingredients Ground wheat, 16.1% protein Soybean meal, 47.8% protein Fish meal, 73.0% protein WOF,1 15.4% protein WOB, 23.9% protein DL-Methionine L-Lysine hydrochloride Dicalcium phosphate Limestone Iodized salt Vitamin-trace mineral premix 2 Dextrose Poultry fat Calculated analyses Crude protein, % ME, kcal/g 1 2

1

2

3

4

5

65.0 21.4

43.3 24.8

21.7 27.2

47.3 21.4

34.7 14.7

1.3

0

21.7

43.3

0 0

0 0

0

0

21.7

43.3

.2 .2 1.6 1.4 .3 .3 0 5.0

.2 .2 1.7 1.5 .3 .3 .6 3.2

.3 .4 1.7 1.5 .3 .3 .5 4.8

.3 .7 1.7 1.5 .3 .3 .7 1.9

23.0

23.0

23.0

23.0

23.0

3.2

3.2

3.2

3.2

3.2

3.2 0 0 .2 .2 1.4 1.4 .3 .3 0 6.7

WOF = Wild oat flour, WOB = wild oat bran, ME = metabolizable energy. Prairie Microtech, Regina, Saskatchewan; composition of vitamin-trace mineral premix unavailable.

levels of oat groats in the ration were examined by linear and quadratic regression. RESULTS AND DISCUSSION At 18.6% protein, the WOG contained 50% more protein than the DOG sample (Table 4). The WOG was also higher in crude fiber, crude fat, total ash, and phosphorus than the more plump DOG kernels. The first sample of WOG used in the present study contained an intermediate protein level of 16.4%, which was traced to the significant amount of DOG in the sample. The WOG containing 19.7% protein was roller milled on an Allis Chalmers Experimental Mill to obtain about 50% flour and 50% bran. The high yield of bran was due to the adherence of the outer endosperm, including the protein-rich aleurone, to the pericarp layers. The bran function was rich in crude protein, fat, and fiber as well as ash and phosphorus (Table 4). Although the bran fraction was high in protein (23.9%), the flour still retained 15.4% protein. The WOG samples appeared to contain slightly more arginine and tyrosine than the DOG, and aspartic acid content was lower (Table 4). Otherwise, the amino acid composition of WOG was similar to that of DOG. The milled products from WOG resulted in an

uneven distribution of glutamic acid between flour and bran. Thus, the WOG appeared to represent a more concentrated source of nutrients than DOG or other feed grains. Because screenings and mixed feed oats are priced below that of DOG, the WOG had the potential to reduce the costs of poultry diets. The incorporation of up to 41.4% DOG or WOG + DOG in the starter rations of Experiment 1 had no significant effects on live weight of the broilers or feed conversion at the end of the 4-week experiment (Table 5). But at the 61.6% replacement level, both oat products depressed live weight and feed efficiency quite markedly. The adverse effects of 61.6% of WOG in the diets were confirmed in Experiment 2. These results are not in conformity with those of Hulan et al. (1981) who demonstrated that nearly all of the corn and wheat in broiler rations could be replaced with domestic oat groats without adverse effects on biological performance. In the second experiment, 21.7% of WOF in the diets resulted in weight gains and feed efficiencies comparable to the control (Table 5). However, 21.7% WOB reduced the feed efficiency, and 43.3% of WOF or WOB in the diets caused significant decreases in weight gain and increases in feed conversion ratios.

1

3

2

23.0 3.2 1.0 .5 .5 .4 1.2 268.3

51.4 27.1 10.0 .3 .2 1.7 1.4 .3 .3 7.4

2

23.0 3.2 1.0 .5 .5 .4 1.2 258.9

44.5 25.2 20.0 .3 .2 1.7 1.4 .3 .3 6.1

3

23.0 3.2 1.0 .5 .5 .4 1.2 249.4

37.6 23.2 30.0 .3 .3 1.7 1.5 .3 .3 4.9

4

Basis wheat, $180.00/tonne; wild oats, $130.00/tonne.

WOG = Wild oat groats. Prairie Microtech, Regina, Saskatchewan; composition of vitamin-trace mineral premix unavailable.

23.0 3.2 1.0 .5 .5 .4 1.2 277.8

58.3 29.1 0 .3 .1 1.8 1.4 .3 .3 8.6

Ground wheat, 15.1% protein Soybean meal, 47.8% protein WOG,1 19.0% protein DL-Methionine L-Lysine hydrochloride Dicalcium phosphate Limestone Iodized salt Vitamin-trace mineral premix 2 Poultry fat

Calculated analyses Crude protein, % ME, kcal/g Calcium, % Available phosphorus, % Methionine, % Cystine, % Lysine, % Cost per tonne, $ 3

1

Ingredients

Starter diets

20.0 3.2 .9 .4 .4 .3 1.0 254.1

69.1 19.5 0 .1 .2 1.8 1.4 .3 .3 7.3

1

TABLE 3. Percent composition, calculated analysis, and cost of starter and grower-fin (Experiment 3)

334

BHARGAVA AND SOSULSKI TABLE 4. Proximate, mineral, and amino acid composition of the domestic and wild oat products1

Constituent

DOG

WOG + DOG

WOG

WOF

WOB

Dry matter, % Protein, N X 6.25, % Crude fat, % Crude fiber, % Total ash, % Calcium, % Phosphorus,- %

90.4 12.6 6.9 3.2 1.9 .15 .42

91.1 16.4 6.9 3.3 2.2 .16 .49

92.6 18.6 9.5 3.4 2.5 .17 .60

90.8 15.4 8.3 1.3 1.1 .14 .26

91.7 23.9 12.8 3.9 4.3 .23 .99

Amino acids, g amino acid/ 16 g nitrogen Alanine Arginine Aspartic acid Ammonia Glutamic acid Glycine 1/2 Cystine Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Proline Serine Threonine Tyrosine Tryptophan Valine Total

4.5 5.9 9.1 2.4 20.5 4.7 3.1 2.2 3.5 7.4 4.0 1.5 5.4 4.9 4.6 2.2 3.1 1.6 5.2 95.8

4.4 6.3 8.7 3.2 22.2 4.7 2.7 2.1 3.5 7.3 3.9 1.2 4.9 5.5 4.6 2.4 3.5 1.9 5.5 98.5

4.5 6.6 8.1 2.7 20.0 4.3 2.8 2.5 3.3 7.1 4.0 1.5 5.7 4.6 4.4 2.4 4.0 1.6 5.4 95.5

4.6 6.7 8.1 2.8 21.5 4.1 2.8 2.4 3.4 7.4 3.8 1.7 5.8 4.9 4.4 2.4 3.5 1.5 5.6 97.4

5.1 7.1 8.5 2.7 19.3 4.6 3.0 2.6 3.3 7.4 4.3 1.6 5.7 4.5 4.5 2.5 4.0 1.6 5.8 98.1

1

DOG = Domestic oat groats, WOG = wild oat groats, WOF = wild oat flour, WOB = wild oat bran.

Linear and quadratic regressions of performance on various levels of oat groats in the diet are presented in Table 6. In general, the live weight and feed conversion were curvilinear except the response of feed conversion to level of WOB in Experiment 2 was essentially linear. The multiple correlation coefficients were all significantly different from zero (P<.01), suggesting the amount of oat groats in the diet is extremely useful to predict the performance of birds. The maximum amount of oat groats in the diet started to reduce live weight and feed efficiency at a point where the first derivative of the quadratic equation is zero. For example in Experiment 1, the live weight (Y) was related to the amount of DOG (X) by:

Y = 905.83 + 6.24X -

.19XZ

The maximum amount of DOG in the ration before live weight began to decline was when X = 16.32%. The feed conversion (Y) is related to the amount of DOG (X) by: Y = 1.60725 - .00595X + .00017X 2 The maximum amount of DOG in the ration before feed efficiency started to decline was w h e n X = 17.5%. The growth depressions observed at the higher rates of feeding oat products could not be attributed to deficiencies in methionine or lysine since these amino acids were supplemented in the formulation (Tables 1, 2, and 3). Analyses of the free amino acids in the blood plasma of control chicks and chicks fed the 61.6% WOG failed to show any evidence of amino acid deficiencies.

WILD OAT GROATS IN DIETS TABLE 5. Live weight and feed conversion of broiler chicks fed starter diets which contained domestic (DOG) and wild (WOG) oat groats (Experiment 1), or wild oat flour (WOF) and bran (WOB) (Experiment 2) for 4 weeks

Diet

Experiment 1 1. Control 2. 20.5% DOG 3. 41.4% DOG 4. 61.6% DOG 5. 20.5% WOG + DOG 6. 41.1% WOG + DOG 7. 61.6% WOG + DOG Standard error

Live weight

Feed conversion

(g)

(g/g)

910ab a

1.60bc 1.57 c 1.63bc 1.86a 1.62bc 1.66 b 1.81 a .02

825ab 867 a 686 c

1.67bc 1.60C 1.78ab 1.88a 2.20 d 1.91 a .05

943 862ab 589 c 892ab 843b 654 c 26

Experiment 2 1. Control 2. 21.7% WOF 3. 43.3% WOF 4. 21.7% WOB 5. 43.3% WOB 6. 61.6% WOG Standard error

747DC

559d 594d 26

within experiments, numbers with different superscripts are significandy different (P<.05) from other numbers in that column (n=4).

335

T h e results of this s t u d y suggest t h a t t h e adverse effects of t h e high o a t diets p r o b a b l y arose from t h e n o n p r o t e i n fractions of t h e kernel. Beta-glucans in t h e barley a n d oats are k n o w n t o cause sticky feces and g r o w t h depression ( G o h l et al, 1978). A l t h o u g h sticky feces were n o t induced b y the present diets, it was possible t h a t these c o m p l e x c a r b o h y d r a t e s of t h e o u t e r e n d o s p e r m had an adverse effect on chick growth. Based on t h e results obtained with starter diets, an e x p e r i m e n t was designed t o provide u p t o 30% WOG in broiler rations' w h e r e t h e chicks w e r e being fed t o m a r k e t weight (49 days) (Table 3). Diets containing 10.0, 20.0, and 30.0% WOG s u p p o r t e d similar weight gains a n d feed efficiencies as t h e control diet (Table 7). Carcass quality was as good or b e t t e r t h a n was o b t a i n e d for birds fed t h e control diet. T h e liver and kidney weights of t h e m a r k e t birds were similar, irrespective of t h e level of WOG in t h e diets. Linear p r o g r a m m i n g showed t h a t WOG were effective in reducing t h e costs of t h e diet in p r o p o r t i o n t o t h e level of i n c o r p o r a t i o n (Table 3). This resulted in a saving in feed costs of $.12/bird w h e n t h e broilers were raised t o m a r k e t age (Table 7). However, a l t h o u g h statistically n o t significant, this saving in feed cost was offset by a 2.4% r e d u c t i o n in live weight a n d 2.9% increase in feed conversion.

TABLE 6. Relationship between live weight or feed conversion (Y) and level of oat products (X) in the broiler diets1 Dependent variable (Y) Experiment 1 Live weight Feed conversion Experiment 2 Live weight Feed conversion

Independent variable (X)

Regression equation

SET

DOG WOG + DOG DOG WOG + DOG

Y = 905.83 + 6.24X - .19X 2 Y = 904.29 + 2 . 3 1 X - .11X 2 Y = 1.60725 - .00595X + .00017X 2 Y = 1.60612 - .00144X + .00008X 2

54.6 46.4 .054 .040

.94 .92 .92 .92

WOF WOB WOF WOB

Y = 8 2 5 . 5 0 + 7 . 6 4 X - .28X 2 Y = 825.50 - 1.21X - .14X 2 Y = 1.67250 - .0095X + .00032X 2 Y = 1.67250 + .00819X

45.4 56.2 .064 .135

.89 .92 .80 .88

1

n=16 in Experiment 1 and n=12 in Experiment 2.

2

SEy = Standard error of y.

3

r = Multiple correlation coefficient, all significantly different from zero at P<.01.

336

BHARGAVA AND SOSULSKI TABLE 7. Effects of fee ding various levels of wild oat groats (WOG) on growth performance, carcass quality, organ weights, and feed cost of chicks to market age (Experimen 13)

Live weight

Feed conversion

Carcass grade

Liver weight

(%)

(g)

(g/g)

(% A)

(g/kg)

(g/kg)

.0 10.0 20.0 30.0

2101a 2078 a 2035 a 2051a

2.08 a 2.12 a 2.17 a 2.14 a

63.3 a 70.9 a 66.4 a 81.8 a

21.4 a 22.7 a 22.3 a 21.2 a

7.2 a 7.6 a 7.1 a 7.6 a

1.12 a 1.09 a 1.05 a 1.00°

.4

.01

WOG in diets

Standard error a,b

24

.02

4.8

.5

Kidney weight

Feed cost per bird

($)

Numbers with different superscripts are significantly different (P<.05) from other numbers in that column

(n=4).

ACKNOWLEDGMENTS T h e a u t h o r s wish t o t h a n k H. Braitenbach a n d L. Campbell for assistance w i t h t h e investigation. We are grateful t o A. K. Tong, Research Scientist, Agriculture Canada Research Station, Lacombe, for his kind direction in t h e statistical analysis.

REFERENCES Association of Official Agricultural Chemists, 1970. Official Methods of Analysis. 10th ed. Assoc. Offic. Agric. Chem., Washington, DC. Dunkelgod, K. E., and G. E. Winkleman, 1982. Free amino acids in the plasma of poults used as an indicator of possible limiting amino acids in presently available protein sources. Poultry Sci. 6 1 : 1674-1683. Gohl, B., S. Alden, K. Elwinger, and S. Thomke, 1978.

Influence of /3-glucanase on feeding value of barley for poultry and moisture content of excreta. Br. Poult. Sci. 19:41-47. Hulan, H. W., F. G. Proudfoot, and C. G. Zarkadas. 1981. Nutritive value and quality of oat groats for broiler chicks. Can. J. Anim. Sci. 61:1013 — 1021. National Research Council, 1977. No. 1. Nutrient Requirements of Poultry. National Academy of Sciences. 7th ed. Washington, DC. Sosulski, F. W., and K. Sosulski, 1985. Processing and composition of wild oat groats (Averia fatua L.). J. Food Engin. 4 : 1 8 9 - 2 0 3 . Sosulski, F. W., K. Sosulski, and J. Olson, 1985. Nutritive value of wild oat groat and flakes. Can. Inst. Food Sci. Technol. J. (in press). Steel, R.G.D., and J. H. Torrie. 1960. Principles and Procedures of Statistics. McGraw-Hill Book Co., Inc., New York, NY. Tkachuk, R., and V. J. Mellish, 1977. Amino acid and proximate analysis of weed seeds. Can. J. Plant Sci. 57:243-249.