EDUCATION AND PRODUCTION. Performance Characteristics and Economic Comparison of Broiler Chickens Fed Wheat- and Triticale-Based Diets

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1 EDUCATION AND PRODUCTION Performance Characteristics and Economic Comparison of Broiler Chickens Fed Wheat- and Triticale-Based Diets D. R. Korver,*,1 M. J. Zuidhof, and K. R. Lawes* *Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada; and Livestock Development Division, Pork, Poultry and Dairy Branch, Alberta Agriculture, Food and Rural Development, Edmonton, Alberta, Canada T6H 5T6 ABSTRACT The effects of triticale and wheat on broiler recorded in each barn at 0, 19, 34, and 42 d, corresponding (mixed sexes) performance and cost of production were compared. In experiment 1, wheat- and triticale-based to the beginning and end of each dietary phase. Feed consumption and FCR were calculated for each barn. An diets were fed to 3 strains of broilers (Ross Ross, Hubbard Hubbard, and Ross Hubbard). Each of the diets chicken production cost model. Final BW, feed consump- analysis of each of the diets was calculated using a broiler was provided to 5 cages/strain (n = 10 chicks/cage; 1,273 tion, carcass weight at processing, flock uniformity, percentage of Grade A carcasses, and percentage of con- cm 2 /bird). Weekly BW, gain, feed consumption, and feed conversion ratio (FCR; g of feed/g of gain) were determined. At 42 d, 4 chicks/pen were shipped to a commerdemned carcasses were not affected by cereal source. Overall FCR (2.165, 2.036; P = ), feed cost ($0.617, cial processing plant. The plucked, eviscerated carcasses $0.577/kg live weight; P = ), and total cost of production ($1.019, $0.972/kg live weight; P = ) were were evaluated for carcass traits. Overall, the triticale-fed birds had lower final BW and average daily gain and higher FCR. Eviscerated carcass, thigh, and drum weights greater for the triticale than wheat diets, respectively. were lower, but pectoralis minor as a percentage of carcass weight was greater in triticale-fed birds. In experi- for wheat in broiler diets when its price is less than or Triticale would be an economically feasible replacement ment 2, a wheat diet and a diet in which triticale was equal to 95% of the cost of wheat, less $18 (Canadian). substituted (by weight) for wheat were provided in a Increased knowledge of the available nutrient profile of 3-phase feeding program. Each diet was provided to 2 identically-equipped commercial barns housing 17,034 broilers each. Individual BW of a sample of birds were triticale, as well as least-cost feed formulation would likely increase the value of triticale relative to wheat for broilers. (Key words: broiler, cost of production, triticale, wheat) 2004 Poultry Science 83: INTRODUCTION Triticale is an alternative cereal grain that is a hybrid of wheat and rye. These species were crossed with the intention of producing a grain with the feeding characteristics of wheat and the winter hardiness, drought and disease resistance of rye (Boros, 1999). Triticale has an excellent productivity potential (Gatel et al., 1985; Vohra et al., 1991) and a greater flexibility to adapt to difficult agronomic conditions than wheat (Gatel et al., 1985). However, early triticale varieties had poor feeding characteristics relative to wheat, and triticale developed a reputation of being unsuitable in poultry diets (Sell et al., 1962; 2004 Poultry Science Association, Inc. Received for publication July 16, Accepted for publication November 17, To whom correspondence should be addressed: doug.korver@ ualberta.ca. Fernandez and McGinnis, 1974; Wilson and McNab, 1975). One of the outstanding features of triticale has traditionally been its protein content. Gatel et al. (1985) reported that with an equal crude protein content, triticale is richer in lysine than wheat, comparable to wheat in threonine and sulfur amino acid contents but slightly poorer in tryptophan than wheat. Salmon (1984) found that triticale contained more lysine, arginine, aspartic acid, and alanine than wheat. Boldaji et al. (1986) reported no significant difference in apparent, true, and nitrogencorrected metabolizable energy among 3 varieties of triticale and 3 varieties of wheat. Plant breeders have continued to develop triticale to improve its value for poultry diets. Maurice et al. (1989) explained that genetic improvements to triticale have increased grain plumpness and lowered the protein content. Abbreviation Key: FCR = feed conversion ratio; P. = pectoralis. 716

2 TRITICALE IN BROILER DIETS 717 TABLE 1. Diet composition and nutrient content of triticale and wheat starter, grower and finisher diets (experiment 1) Starter diet 1 (%) Grower diet 2 (%) Finisher diet 3 (%) Ingredient Triticale Wheat Triticale Wheat Triticale Wheat Triticale Wheat Soybean meal Alfalfa meal 7.0 Canola meal Meat meal Tallow Feather meal Canola oil Fish meal Limestone Calcium phosphate Microingredients Nutrient composition ME (kcal/kg) 5 2,944 2,926 2,924 2,921 2,949 2,926 Crude protein, % Crude protein, % Ca, % Ca, % Total P, % Available P, % Na Lys, % Met, % Met + Cys, % Thr, % Starter diets, fed from 0 to 19 d, contained Maxiban (Elanco Animal Nutrition, Guelph, ON, Canada) as a coccidiostat. 2 Grower diets, fed from 20 to 35 d, contained Sacox 120 (Intervet Canada, Whitby, ON, Canada) as a coccidiostat. 3 Finisher diets, fed from 36 to 41 d, contained Sacox 120 (Intervet Canada) as a coccidiostat. 4 Proprietary microingredient formulation of a commercial feed mill formulated to meet or exceed NRC (1994) recommendations for broiler chickens, including Avizyme 1300 (Danisco Animal Nutrition, Marlborough, Wiltshire, UK), L-lysine HCl, DL-methionine, L-threonine, salt, selenium premix, vitamin premix, mineral premix, Bacitracin methylene Disalicylate (BMD 110 G, Alpharma, Mississauga, ON, Canada), choline chloride 60% premix, sodium bicarbonate. 5 Calculated composition. 6 Analyzed composition. Boros (1999) proposed that the negative effects observed in early triticale varieties are less prominent in newer varieties that have a smaller proportion of the rye genome compared with the wheat genome. The purpose of the present studies was to compare the performance of broiler chicks fed triticale- and wheatbased diets under small-scale experimental and commercial conditions and to infer from the results the economic value of triticale relative to wheat. Experiment 1 MATERIALS AND METHODS The Faculty Animal Policy and Welfare Committee of the University of Alberta approved all procedures. Experiment 1 was a 2 diet 3 broiler strain factorial arrangement of treatments, with diet and broiler strain as the main effects. Day-old broiler (mixed sex) chicks were obtained from a commercial hatchery. 2 Three broiler crosses 2 Lilydale Foods, Ltd., Edmonton, AB, Canada. 3 Avizyme 1300, Danisco Animal Nutrition, Marlborough, Wiltshire, UK. (n = 100/strain of Ross 308 Ross 308, Hubbard HiY Hubbard HiY and Ross 308 Hubbard HiY) were housed in pullet rearing cages. Ten birds of the same strain were housed in each cage (10 cages/strain) at a stocking density of 7.86 birds/m 2. Two experimental mash diets with either hard red spring wheat or triticale (Pika variety) as the primary cereal source were formulated to be approximately isocaloric and isonitrogenous and meet or exceed National Research Council specifications (1994; Table 1). A commercial arabinoxylanase preparation (Avizyme ) was included in both dietary treatments, as arabinoxylans are the major water-soluble nonstarch polysaccharides of wheat, rye, and the wheat-rye hybrid triticale (Bonnin et al., 1998; Mathlouthi et al., 2002). The diets were based on proprietary microingredient formulations of a commercial feed mill. Table 1 provides a list of the microingredients included but not the quantities. Each of the dietary treatments was fed to 5 cages of each strain of chicks and provided as a starter diet from 0 to 19 d, as a grower diet from 20 to 35 d, and as a finisher diet from 36 d to the end of the experiment at 41 d. Birds were allowed free access to the feed and fresh water from

3 718 KORVER ET AL. nipple drinkers (4 nipples/cage) throughout the experiment. Light was provided for 23 h/d. Room temperature on 0 d was 30 C and decreased approximately 3 C per week until 20 C was reached, according to standard poultry rearing practices. Analysis of all diets fed was performed by a commercial feed testing laboratory. 4 Body weights and feed intake on a cage basis were determined weekly, and feed conversion ratio (FCR) was calculated. Mortality was recorded, and group weights and FCR were corrected for mortality. On d 41, all birds were individually weighed; 4 birds per cage (n = 20 per diet x strain interaction) were randomly selected and individually wing-banded for identification during processing. The selected birds were then placed in crates and processed at a commercial processing plant. 5 Plucked eviscerated carcasses were returned to the Alberta Chicken Producers Poultry Technology Centre for cutup and determination of portion yield. Carcasses were weighed, necks were removed, and carcasses were cut into front and back halves. Drums and thighs were separated and weighed. Wings, pectoralis (P.) minor, and P. major were removed and weighed. Experiment 2 Broiler chicks (n = 68,136) were obtained from the same commercial hatchery as in experiment 1 and housed in 1 of 4 commercial barns (n = 17,034 birds; barn area = 892 m 2 each) at a stocking density of 19.1 birds/m 2. The barns were similarly equipped with nipple drinkers (14.2 birds/nipple) and pan feeders (53.2 birds/pan). Within each barn, chicks were placed such that the distribution of chicks from several parent flocks and strain crosses was uniform (Table 2). Birds in 2 of the barns received a hard red spring wheat-based diet, and those in the remaining 2 barns received a triticale (Pronghorn variety) diet. The birds were fed a starter diet from 0 to 19 d, a grower diet from 20 to 34 d, and a finisher diet from 35 to 42 d (Table 3). The starter, grower, and finisher diets contained a similar level of the respective cereal grain, crude protein, and essential amino acids. A commercial arabinoxylanase preparation (Avizyme ) was included in both dietary treatments. At placement, a random sample of chicks (n = 178 per barn) from each barn was individually weighed. At 19 and 34 d, group weights were recorded for a sample of birds in each barn. In order to weigh a random sample, a mobile catching pen was used to enclose a group of approximately 150 birds near the center of each barn. All of the birds within this group were then weighed individually (n = at least 128/barn on each day). At 42 d, birds were loaded and shipped to a commercial processing plant. 5 Three lots of broilers (n = 6,517, 6,800, 4 Norwest Labs, Lethbridge, AB, Canada. 5 Hinse Poultry, Beaumont, AB, Canada. 6 Alberta Agriculture, Food and Rural Development, and Alberta Chicken Producers, 1997, Version 1.02, Edmonton, AB, Canada. TABLE 2. Distribution of broilers from various strains within each commercial barn (experiment 2) Breeder flock Total birds Strain age (wk) placed Hubbard Hubbard ,224 Arbor Acres Arbor Acres ,060 Arbor Acres Arbor Acres 34 6,222 Hubbard Ross ,448 Arbor Acres Arbor Acres 57 2,448 Hubbard Ross Hubbard Ross Total 17,034 1 All Hubbard parent stock were Hubbard HiY. 2 All Arbor Acres parent stock were Arbor Acres Classic. 3 All Ross parent stock were Ross 308. and 5,740; total = 19,057) from the triticale-fed barns and 4 lots of broilers (n = 6,800, 8,362, 8,537, and 5,012; total = 28,711) were shipped separately to the processing plant. Average live weight for each lot and individual carcass weight of each bird were measured by inline weighing equipment at the processing plant. For each lot, CV was calculated as an indicator of flock uniformity of carcass weights, and the number of grade A carcasses was recorded. For these data, the lot was the experimental unit. Feed consumption for each barn was calculated based on the amount of feed delivered and an estimate of the feed remaining in the respective feed bins. Economic Analysis An analysis was conducted to compare the economic implications of feeding triticale and wheat diets. A production unit producing 150,000 kg of live broilers per 8- wk cycle was simulated using the Chickcop broiler chicken production cost model. 6 Field performance data for each experimental unit (barn) in experiment 2 were used as inputs in the economic analysis. Feed prices for the wheat- and triticale-based starter diets were $290 and $298/ton, respectively; grower diets were $276 and $282/ ton, respectively; and finisher diets were $ and /ton, respectively. A chick price of $0.515/chick was used. Input data used in the economic model are provided in Table 4.Total costs, feed costs, and chick costs, generated on a dollars per kilogram basis, were calculated for each experimental unit. All values are reported in Canadian dollars. Calculation of Economic Breakpoint. The cost of the cereal and noncereal fractions of the diets in experiment 2 was calculated. The cost of each diet was recalculated for wheat and triticale prices ranging from $100 to $200/ ton, in $10/ton increments. The relationship between cereal cost and total production cost was estimated by regressing the cost of production on the cost of each cereal by using the calculated diet prices as inputs in a deterministic economic simulation using Chickcop (equation 1). COP c = β 0c + β 1c P c [1]

4 TRITICALE IN BROILER DIETS 719 TABLE 3. Diet composition and nutrient content of triticale and wheat starter, grower and finisher diets (experiment 2) Starter diet 1 (%) Grower diet 2 (%) Finisher diet 3 (%) Ingredient Wheat Triticale Wheat Triticale Wheat Triticale Triticale Wheat Soybean meal Canola meal Meat meal Fish meal Feather meal Tallow Canola oil Limestone Calcium phosphate Microingredients Calculated nutrient composition ME (kcal/kg) 5 2,926 3,023 2,902 3,003 2,948 3,046 Crude protein, % Crude protein, % Ca, % Ca, % Total P, % Total P, % Available P, % Na, % Lys, % Met, % Met + Cys, % Thr, % Starter diets, fed from 0 to 13 d, contained Maxiban (Elanco Animal Nutrition, Guelph, ON, Canada) as a coccidiostat. 2 Grower diets, fed from 14 to 33 d, contained Maxiban (Elanco Animal Nutrition) as a coccidiostat. 3 Finisher diets, fed from 34 to 41 d, contained Coyden 25% (Intervet Canada, Whitby, ON, Canada) as a coccidiostat. 4 Proprietary microingredient formulation of a commercial feed mill formulated to meet or exceed NRC (1994) recommendations for broiler chickens, including Avizyme 1302 (Danisco Animal Nutrition, Marlborough, Wiltshire, UK), L-lysine HCl, DL-methionine, L-threonine, salt, selenium premix, vitamin premix, mineral premix, zinc bacitracin (Albac 110, Alpharma, Mississauga, ON, Canada), choline chloride 60% premix, sodium bicarbonate. 5 Calculated composition. 6 Analyzed composition. where COP c is the cost of production ($/kg live) of broilers using diets with cereal source c, P c is the price ($/ ton) of cereal c, and β c is a vector of linear estimation parameters for cereal c. For triticale to be used economically, cost of production using triticale must be less than or equal to the cost of production using wheat as a dietary cereal source (COP t COP w ). By rearranging to isolate P t, the triticale price TABLE 4. Input data from the 4 experimental units used to calculate the economic implications of the commercial use of triticale diets (experiment 2) Market FCR 3 Feed consumption (g/bird) weight 2 Mortality Condemnations (g of feed/ Barn 1 Diet (g) (%) (%) g of gain) Starter 4 Grower 5 Finisher 6 11 Wheat 2, ,928 1, Wheat 2, ,129 1, Triticale 2, ,960 1, Triticale 2, ,970 1,932 1 Commercial barns; each barn was 892 m 2 and housed 17,034 birds at placement at a stocking density of 19.1 birds/m 2. Each of the barns was similarly equipped with nipple drinkers (14.2 birds/nipple) and pan feeders (53.2 birds/pan). 2 Average body weight at 42 d of age. 3 Feed conversion ratio. 4 Starter diets fed from 0 to 13 d of age. 5 Grower diets fed from 14 to 33 d of age. 6 Finisher diets fed from 34 to 42 d of age.

5 720 KORVER ET AL. at which triticale can be used at equal or greater economic efficiency than wheat can be determined (equation 2). P t β 0w β 0t + β 1w P w β 1t [2] The following assumptions and limitations apply to this analysis: 1. Live performance and production costs in experiment 2 were realistic and reproducible. 2. Diet formulation does not change with fluctuating cereal and other ingredient costs. This analysis therefore represents the relative economic value of triticale and wheat under the conditions of experiment Economic analysis was limited to live production costs. Any yield or conformation differences that affect supply chain economics were not incorporated into this analysis. Statistical Analysis In experiment 1, the cage was the experimental unit for BW gain and feed intake data. The bird was the experimental unit for the processing data. The data were analyzed as a 2-way analysis of variance using the GLM procedure of SAS software (SAS Institute, 1999), with dietary treatment and broiler strain as main effects. Each strain diet combination had 5 replicates. Differences between means were analyzed using the least significant difference test. In experiment 2, the barn was the experimental unit for BW at 0, 19, and 34 d, feed consumption and FCR data. The shipping lot was the experimental unit for 42-d BW. The bird was the experimental unit for the processing data. The data were analyzed as a one-way analysis of variance with dietary treatment as the main effect. Total costs, feed costs, and chick costs ($/kg live) were analyzed using a one-way analysis of variance (SAS Institute, 1999). Differences between means are reported at the P < 0.05 level unless otherwise stated. Experiment 1 RESULTS In experiment 1, initial weights were not different among dietary treatments. However, by 41 d of age, birds on the triticale treatment weighed 6% less than those on the wheat treatment (P = ; Table 5). Average daily BW gain during wk 2 (P = ), during wk 3 (P = ), and over the course of the experiment (P = ) was greater for the wheat-fed birds than for the triticalefed birds. Average initial weight of the Ross Hubbard birds was lower than birds of the Ross Ross and Hubbard Hubbard strains (P < ). The Ross Ross and Hubbard Hubbard birds gained more BW per day than the Ross Hubbard broilers in wk 1 and 2 and over the entire experiment (P < 0.02). Differences among strains in average final weight approached significance (P = ). In wk 2 there was an interaction between strain and diet effects (data not shown). The Ross Hubbard broilers fed the wheat diet had a significantly higher rate of gain than those fed the triticale diet (P = ). The Ross Ross broilers showed a nonsignificant trend toward higher gain when fed the wheat diet (P = ). The difference between the dietary treatments for the Hubbard Hubbard broilers was not significant. Feed intake was not significantly affected by dietary treatment (Table 5). Feed intake over the course of the entire experiment was not influenced by either main effect, although the Ross Ross and Hubbard Hubbard birds consumed more feed during wk 1 than the Ross Hubbard birds (P = ). Both diet and strain had an effect on FCR of the birds. The wheat diet resulted in a significantly lower FCR in wk 2, 3, 6 and over wk 1 to 6 (P < 0.01; Table 5). The Ross Ross and Ross Hubbard birds had higher FCR than the Hubbard Hubbard birds during wk 3 (P = ). Over the course of the entire experiment, the Ross Hubbard strain was the least efficient at converting feed to gain (P = ). There was a strain by diet interaction for FCR over the course of the entire experiment (P = ). The FCR of the Ross x Ross and Ross x Hubbard strains was higher for the triticale diet than the wheat diet, but there was no difference due to diet in FCR of the Hubbard Hubbard birds. Total mortality in this experiment was 8%. Of the total mortalities, 55% were in the wheat treatment group, and 45% were in the triticale treatment group. Ross Ross birds accounted for 9% of the mortality, Hubbard Hubbard birds accounted for 36% of the mortality, and Ross Hubbard birds accounted for 55% of the mortality (data not shown). Broilers fed triticale had lower 41 d live, eviscerated carcass, back half, front half, drum, and thigh weights (P < 0.05; Table 6) than those fed wheat. P. major, P. minor, and wing weights were not affected by dietary treatment. Because of a lower average eviscerated carcass weight, the P. minor as a proportion of carcass weight of the triticale-fed birds was significantly higher than for the wheat-fed birds (P = ). The Ross Hubbard birds had significantly greater proportion of P. major than either of the other 2 crosses (P = ). There was a significant diet by strain interaction for P. major proportion, in which the Ross Ross birds fed triticale had a higher proportion of P. major than those fed wheat, whereas diet had no effect on P. major proportion of the other crosses. Experiment 2 Initial BW of the chicks in each dietary treatment group were not different (Table 7). Birds fed the wheat diet were larger than those fed the triticale diet at 19 d (P = ), but at 34 and 42 d, treatment differences in BW were not significant. Neither feed consumption from 0 to 42 d of age nor mortality was affected by dietary treatment. FCR was significantly higher for birds fed the triti-

6 TRITICALE IN BROILER DIETS 721 TABLE 5. Average performance traits of broilers fed either wheat- or triticale-based diets (experiment 1) BW d 0 BW d 42 (g) (g) Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 Wk 6 Wk 1 6 Body weight gain (g/chick per d) Diet 1 Wheat ,096 a a 49.1 a a Triticale ,972 b b 42.5 b b Strain 2 R R a 2, a 36.9 a a H H a 2, a 35.2 a a R H b 1, b 31.8 b b Pooled SEM P-value Diet NS NS NS NS Strain NS NS NS Interaction NS NS NS NS NS NS NS Feed intake (g/chick per d) Diet Wheat Triticale Strain R R 19.5 a H H 19.1 a R H 17.5 b Pooled SEM P-value Diet NS NS NS NS Strain NS NS NS NS NS Interaction NS NS NS NS NS NS Feed conversion efficiency (g of feed/g of gain) Diet Wheat b 1.51 b b 1.72 b Triticale a 1.73 a a 1.88 a Strain R R a b H H b b R H a a Pooled SEM P-value Diet NS Strain NS NS NS Interaction NS NS NS a,b Means within a column within a main effect are significantly different (P 0.05). 1 Each dietary treatment was fed to 15 pens of 10 chicks per pen. 2 For each strain, birds were placed in 10 pullet rearing cages (n = 10 birds per cage). 3 Ross 308 Ross Hubbard HiY Hubbard HiY. 5 Ross 308 Hubbard HiY. cale diet (P = ). As observed for 42 d live weight, dietary treatment had no effect on carcass weight (Table 8). Likewise, uniformity of carcass weights (measured as CV), percentage of grade-a carcasses, and percentage of birds condemned were not affected by dietary treatment. Total live production costs were $0.047/kg higher in flocks fed the triticale diets compared with those fed the wheat diets (P = ; Table 8). Together, feed and chick costs accounted for 98% of the difference in total production cost; 84% of that difference was due to increased feed costs, which were $0.617/kg live in triticalefed flocks and $0.577/kg live in wheat-fed flocks (P = ); 14% of the difference was due to increased chick costs. Chick costs were numerically higher in triticale-fed flocks because of higher flock mortality. In the simulation, more chicks were required to produce the same number of live kilograms of broilers. The difference in feed plus chick costs was $0.046/kg live ($0.883 and $0.837/kg live for the triticale and wheat treatments, respectively; P = ). Regression equations relating the total cost of production with cereal prices were calculated for triticale (equation 3) and for wheat (equation 4). COP t = P t (R 2 = 1) [3] COP w = P w (R 2 = 1) [4] The R 2 values for the equations equal 1 because the simulation was deterministic, and therefore there was no variability predicted for COP. The triticale price relative to the price of wheat at which triticale can be used economically and simplified to

7 722 KORVER ET AL. TABLE 6. Carcass and portion weights and yield 1 at 41 d of broilers fed wheat- or triticale-based diets (experiment 1) Live Eviscerated Back Front Pectoralis Pectoralis Item BW carcass half Thigh Drum half minor major Wing Weight (g) Diet 2 Wheat 2,101 a 1,415 a a a a a Triticale 2,007 b 1,331 b b b b b Strain 3 R R 4 2,039 1, H H 5 2,102 1, H R 6 2,021 1, Pooled SEM P-value Diet NS Strain NS NS NS NS NS NS NS NS Interaction NS NS NS NS NS NS NS NS Yield (%) Diet Wheat b Triticale a Strain R R b 11.5 H H b 11.5 H R a 11.2 Pooled SEM P-value Diet NS NS NS Strain NS NS NS NS NS Interaction NS NS NS NS NS a,b Means within a column within a main effect are significantly different (P 0.05). 1 Expressed as carcass weight as a percentage of live weight (carcass) or as portion weight as a percentage of eviscerated carcass weight. 2 Each dietary treatment was fed to 15 pens of 10 chicks per pen. 3 For each strain, birds were placed in 10 pullet rearing cages (n = 10 birds per cage). 4 Ross 308 Ross Hubbard HiY Hubbard HiY. 6 Hubbard HiY Ross 308. P t 0.95 P w 18.0 [5] Based on this equation, triticale would be an economically viable substitute for wheat when the price of triticale is 95% of the price of wheat less $18 (Canadian). BW DISCUSSION In experiment 1, complete replacement of wheat in broiler diets with triticale resulted in decreased BW gain to market weight; there was no diet effect in experiment 2. The variability in results may be due to a number of factors. The triticale variety used in experiment 1 was Pika, a hexaploid winter variety. In experiment 2, Pronghorn triticale, a hexaploid spring variety was used. In experiment 2, the objective was to maintain, as much as possible, consistency of the noncereal ingredients. Although the diets calculated were isonitrogenous and quite consistent among dietary treatments in most nutrients, calculated energy values of the triticale diets were slightly higher than those for the wheat diets. Variable results in triticale feeding trials are widespread in the literature. The negative effects of dietary triticale observed in experiment 1 are similar to those previously reported by others (Gerry, 1975; Ruiz et al., 1987; Proudfoot and Hulan, 1988; Smith et al., 1989). However, others have observed no detrimental effect of triticale in poultry feeding trials. Johnson and Eason (1988) observed that growth of broiler chickens was similar whether triticale or wheat was the cereal source in diets that contained 50% cereal and were equalized for nutrient content. Similarly, Vieira et al. (1995) found that the graded inclusion of triticale up to 40% (substituted for corn) had no negative effect on weight gain or final weight of broilers. In those studies, the limited replacement of the main cereal grain might have hidden any negative effects of triticale. Complete replacement of corn with triticale in the diets of White Leghorn pullets did not affect BW (Lesson and Summers, 1987). Further, pigs fed triticale-based diets had average daily gains that were similar (P > 0.10) to that of pigs fed soft red winter wheat- or corn-soybean meal control diets (Myer et al., 1996). Feed Intake and FCR Within each experiment, feed intake of the triticale diets was, for the most part, not different from that of the wheat diets, indicating that triticale did not have a negative effect on palatability of the diets. However, the FCR of birds fed the triticale-based diets was higher in both ex-

8 TRITICALE IN BROILER DIETS 723 TABLE 7. Average performance and carcass quality traits of broilers fed either wheat- or triticale-based diets (experiment 2) Days 0 to 42 Carcass Body weight (g) Feed FCR Weight CV Grade A Condemned Diet d 0 1 d19 1 d34 1 d42 2 consumption (g) (g of feed/g of gain) Mortality (%) (g) (%) (%) (%) Wheat a 1,533 2,068 4, b 4.8 1, Triticale b 1,519 2,074 4, a 6.9 1, Pooled SEM P-value NS NS NS NS NS NS NS NS NS a,b Means within a column within a main effect are significantly different (P 0.05). 1 Individual bird weights of a random sample of chicks (n = 178/barn) were determined on d 0. At d 19 and 34, a mobile catching pen was used to randomly isolate a small group of birds within each barn. All of the birds within the pen were weighed individually (n = at least 128 per barn on each day). 2 Average body weights were determined at the processing plant for each of 3 lots of birds (n = 3 lots of 6,517, 6,800, and 5,740 birds, respectively) from the triticale treatment group and from 4 lots of birds (n = 4 lots of 6,800, 8,362, 8,537, and 5,012 birds, respectively) from the wheat treatment group. periments. Decreased efficiency of utilization of the triticale diets suggests that calculated nutrient values of triticale (NRC, 1994) might not have been representative of the nutrient content of the triticale used in the present study. The poorer FCR of the triticale-fed birds may be due to lower nutrient amounts, limited nutrient availability, or antinutritional factors not found to the same extent in wheat. Antinutritional factors in triticale include soluble pentosans (Pettersson and Aman, 1988; Rundgren, 1988), trypsin inhibitor, alkyl resorcinols, and pectins (Smith et al., 1989). The viscosity of triticale extracts was highly correlated with the sum of water-extractable arabinoxylans and β-glucans (Mathlouthi et al., 2002). Likewise, the AME value of triticale was highly negatively correlated with the sum of pentosans and β-glucans (Choct and Annison, 1990). Newer varieties of triticale have been reported to have levels of arabinoxylans and β-glucans that are much lower than those in rye and comparable to certain varieties of wheat (Mathlouthi et al., 2002). In some reports, triticale feeding has resulted in similar or improved feed efficiency relative to other grains. Ruiz et al. (1987) determined that feed efficiency was significantly better for chicks fed triticale than for those fed corn. In quail, Vohra et al. (1991) found no statistically significant differences in FCR among quail fed triticale- or corn-based diets to 21 d of age. However, other researchers have observed poorer FCR with triticale-based diets in broilers (Gerry, 1975; Proudfoot and Hulan, 1988; Vieira et al., 1995). Smith et al. (1989) re- ported 4 to 5% reduction in average FCR for broilers fed triticale compared with a corn control diet from 0 to 2 wk and from 2 to 3 wk of age. Myer et al. (1996) found a similar effect on FCR with pigs fed triticale or wheat. In addition to variability in triticale genotypes, bird genotype may affect the results obtained in triticale feeding. In experiment 1, the diet-by-strain interaction for FCR suggested that the Ross Ross and Ross Hubbard birds were less efficient at extracting nutrients from the triticale diet than the Hubbard Hubbard birds. Triticale had a positive effect on Ross Ross broilers by increasing the percentage of P. minor and total breast muscle weights. Proudfoot and Hulan (1988) also reported a genotype-by-diet interaction for FCR to 42 d in a triticale feeding experiment involving broiler chickens. Carcass Characteristics In experiment 1, triticale feeding had a negative effect on eviscerated carcass weight and many portion weights. P. major, P. minor, and wing weights were not different due to dietary treatment, suggesting that the negative effects of triticale on portion and carcass weights seemed to be largely due to differences in dark meat portions. Although several of the portion weights were decreased by triticale feeding, much of this effect was due to the smaller carcasses. When the results were expressed as portion weight as a percentage of eviscerated carcass weight, there were no differences due to diet except an TABLE 8. Cost of production (Canadian dollars) of broilers fed either wheator triticale-based diets (experiment 2) Total cost of Diet Feed cost 1 Chick cost 1 production 1 ($/kg of live weight) Wheat b b Triticale a a Pooled SEM P-value NS a,b Means within a column within a main effect are significantly different (P 0.05). 1 Analyzed using the Chickcop broiler economic model (Alberta Agriculture, Food and Rural Development, Edmonton, AB, Canada, and Alberta Chicken Producers, Edmonton, AB, Canada).

9 724 KORVER ET AL. increase in P. minor proportion of the triticale-fed birds. Similarly, Charalambous et al. (1986) observed that carcass yield, carcass plus edible giblets yield, and dressing percentage were higher in birds fed corn or corn-triticale diets than in broilers fed a diet with triticale as the only cereal grain. Savage et al. (1987) investigated the physical and sensory quality of cooked meat from aged breeder turkey toms fed diets containing varying amounts of triticale. They found that tenderness increased with increasing amounts of dietary triticale as determined by observations of Warner-Bratzler shear values (P < 0.05) and sensory panel scores (P < 0.10). Although not investigated in the present study, the effects of modern cultivars of triticale on meat quality characteristics may be an interesting area for future research. The uniformity of carcass weights, as measured by CV, was not affected by dietary treatment. Although individual live bird BW were not determined on the day of processing, previous research has demonstrated that the CV values obtained for carcass weights within a flock are similar to the CV values obtained for live weights prior to processing (Feddes et al., 2002). Economics of Production The slightly poorer performance of broilers fed the triticale diet necessitates a price advantage for this grain to be economically feasible. Under the conditions of the present study, triticale became economically feasible as a straight wheat replacement in broiler chicken diets when the price was less than or equal to 95% of the price of wheat less $18/ton (Canadian). This information is important to broiler producers where triticale is produced and is available for inclusion in poultry diets. The drought tolerance of triticale may make it an attractive option for broiler production when the availability of wheat is limited and wheat prices are elevated due to drought or other conditions. Although wheat and triticale have similar nutrient composition, and the diet specifications were very similar using triticale as a straight replacement for wheat, there were some minor differences in calculated nutrient composition. Use of least-cost formulation to more precisely meet nutrient specifications in triticale-based diets would probably make triticale appear more favorable as a cereal source than the present results indicate. There was some evidence for improved P. minor breast meat yield using triticale diets; however, it is unlikely to compensate for the relatively large increase in costs of production using triticale diets at this time. Further work on improvements in feeding characteristics through plant breeding and increased knowledge of the feeding of triticale to poultry may increase the economic value of this grain relative to wheat. ACKNOWLEDGMENTS The authors acknowledge the technical support of the staff of the Alberta Poultry Research Centre and Juan Serrano (Federated Co-operatives Ltd., Saskatoon, SK, Canada). Funding for this project was provided by the Alberta Chicken Producers and the Alberta Agricultural Research Institute. REFERENCES Boldaji, F., M. P. Goeger, H. S. Nakaue, G. H. Arscott, and T. F. Savage Apparent, true and nitrogen-corrected metabolizable energy values of different varieties of triticale, wheat and barley in poultry. Nutr. Rep. Int. 33: Bonnin, E., A. LeGoff, L. Saulnier, M. Chaurand, and J.-F. Thibault Preliminary characterization of endogenous wheat arabinoxylan-degrading enzymic extracts. J. Cereal Sci. 28: Boros, D Influence of R genome on the nutritional value of triticale for broiler chicks. Anim. Feed Sci. Technol. 76: Charalambous, K., A. Koumas, and S. Economides The effect of triticale grain on the performance of chicks from birth to nine weeks of age. Tech. Bull. Agric. Res. 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