Nutritive value of high-oleic acid sunflower seed for broiler chickens

Nutritive Value of High-Oleic Acid Sunflower Seed for Broiler Chickens M. L. Rodrı´guez, L. T. Ortiz, C. Alzueta, A. Rebole´,1 and J. Trevin˜o Facultad de Veterinaria, Universidad Complutense, Ciudad Universitaria, 28040 Madrid, Spain

(Key words: high-oleic acid sunflower seed, broiler, age, digestibility, metabolizable energy) 2005 Poultry Science 84:395–402

objective for this oilseed. The seeds of high-oleic acid sunflower varieties are therefore a source of dietary monounsaturated fatty acids (MUFA), and their inclusion in monogastric diets can be particularly valuable to increase the degree of unsaturation of intramuscular fat without the negative effect of lipid oxidation associated with dietary polyunsaturated fatty acids. There is increasing evidence that dietary monounsaturated fatty acid enrichment has a positive effect on cardiovascular health, decreasing low-density lipoprotein cholesterol but not high-density lipoprotein cholesterol in blood plasma, and decreasing the susceptibility of low-density lipoprotein to oxidation (Grundy, 1986; Roche, 2001). As no information to our knowledge is available on the use of high-oleic acid sunflower seed (HOASS) in poultry feeding, the current study involving growing broilers was designed with the following objectives: 1) to determine the ME content of HOASS and 2) to evaluate nutrient digestibility and ME of diets with graded concentration of HOASS fed to broilers at 12 and 42 d of age.

INTRODUCTION Sunflower (Helianthus annuus L.) is one of the most widely cultivated oilseed in the world and ranks third in importance as a source of vegetable oil. Although referred to as sunflower seed, it is more correctly described as an achene, a type of indehiscent fruit. Hybrid varieties contain 380 to 540 g of oil/kg (Crum et al., 1993), which is very rich in linoleic acid. Sunflower seed contains a moderate amount of protein, approximately 40 to 50% as much as soybean seed. In the last few years, unextracted whole seed has been used as a feed ingredient in poultry diets. Several studies (Cheva-Isarakul and Tangtaweewipat, 1991; Ortiz et al., 1998; Rodrı´guez et al., 1998; RothMaier et al., 1998) have shown that this oilseed can be included in broiler diets at relatively high amounts without any adverse effect on performance and nutrient use. However, it has been also reported that a dietary fat source rich in linoleic acid, such as sunflower oil, produces soft fat tissues and greater susceptibility to lipid oxidation of meat (Zollitsh et al., 1997; Sanz et al., 1999). In recent years, the development of sunflower cultivars with oil high in oleic acid has been an important breeding

MATERIALS AND METHODS Test Product A batch of HOASS (cv. Saxo), free of impurities, was obtained from a commercial supplier2 and used in experi-

2005 Poultry Science Association, Inc. Received for publication May 12, 2004. Accepted for publication October 26, 2004. 1 To whom correspondence should be addressed: [email protected]. 2 Koipesol Semillas S.A., 41410 Carmona, Sevilla, Spain.

Abbreviation Key: HOASS = high-oleic acid sunflower seed.

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fed the diets containing 100 and 200 g HOASS/kg gained less weight (P < 0.001) than those fed the diet containing no HOASS at both ages. Differences in feed-to-gain ratio were only significant for the diet with the highest concentration of HOASS. Apparent digestibility of nutrients and dietary AMEn contents of diets increased with age; thus, the mean digestibility of diets for amino acid N and for total fatty acids increased from 82.1 and 68.0% at 12 d to 86.7 and 84.7% at 42 d, respectively, and AMEn content was improved by 6.5%. Inclusion of HOASS in the diet decreased the digestibilities of fat, oleic acid, and total fatty acids. A decrease in the digestibility of aspartic acid, threonine, tyrosine, valine, isoleucine, and AMEn with increasing inclusion level was also observed at 12 d of age.

ABSTRACT Two experiments were conducted to evaluate the use of high-oleic acid sunflower seed (HOASS) in broiler diets. In the first experiment, HOASS was included in a basal diet at 80, 160, 240, and 320 g/kg at the expense of the energy-yielding ingredients, and the AMEn values of the experimental diets were determined. The linear regression equation of AMEn values on rate of inclusion was calculated. Extrapolation value for the AMEn of HOASS at 100% inclusion was 4,224 ± 77 kcal/kg. In the second experiment, diets containing up to 200 g of HOASS/kg were given to broilers (Cobb) from 0 to 42 d, and performance parameters, nutrient digestibility, and AMEn value were determined at 12 and 42 d of age. Birds

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TABLE 1. Composition (g/kg as fed) of high-oleic acid sunflower seed (HOASS) Ingredient

Amino acid

Moisture Crude protein Crude fat Crude fiber NDF1 ADF2 ADL3 Ash

39.4 180.3 444.3 126.0 211.3 149.8 44.0 31.1

Fatty acid content C16:0 C18:0 C18:1n-9 C18:2n-6 C18:3n-3 Total fatty acids

18.4 21.4 336.7 30.0 ND4 417.1

Aspartic acid Glutamic acid Serine Histidine Glycine Threonine Alanine Arginine Tyrosine Valine Methionine Phenylalanine Isoleucine Leucine Lysine

21.3 45.4 10.0 5.5 12.4 8.5 9.5 17.2 5.5 9.4 3.7 10.2 9.0 13.6 5.9

1

ments 1 and 2. Before mixing the experimental diets, the test product was ground to pass through a 3.0-mm screen. A sample of HOASS was analyzed for dry matter, CP, amino acids, crude fat, fatty acids, crude fiber, neutral detergent fiber, acid detergent fiber, acid detergent lignin, and ash (Table 1).

Experiment 1 This experiment was conducted to determine the AMEn value of HOASS with a multilevel assay involving 4 dietary inclusion levels. A corn-soybean meal basal diet (Table 2) was prepared in mash form and formulated to meet or exceed the nutrient requirement for growing broiler chickens (3 to 6 wk of age) recommended by the National Research Council (1994). Ground HOASS (which had an AMEn of 4,130 kcal/kg as determined in our laboratory) was incorporated into the basal diet at 4 concentrations (80, 160, 240, and 320 g/kg) at the expense of the energy-yielding ingredients; DL-methionine was assumed not to be an energy-yielding ingredient. The 5 experimental diets, which contained 0.5% titanium dioxide as an indigestible marker, were evaluated in a balance trial to determine the ME content. One-day-old male chicks of the Cobb strain were obtained from a commercial hatchery.3 The chicks were housed in thermostatically controlled battery cages, exposed to light for 23 h/d, and fed a standard broiler diet for 3 wk. Feed and water were provided ad libitum. On d 22, 60 birds were placed at random in 30 cages for 6 replicates per dietary treatment. The birds received the experimental diets from 22 to 30 d of age. During the last

3

Cobb Espan˜ola S.A., 28805 Alcala´ de Henares, Madrid. IKA Calorimeter C 4000, Janke & Kunkel GmbH, Staufen, Germany. 5 Sigma-Aldrich Quı´mica, SA, 28100 Alcobendas, Madrid. 6 Chrompack Instrumental BV, Middelbourg, The Netherlands. 4

Experiment 2 The objective of this experiment was to study the influence of bird age on nutrient digestibility and AMEn value of diets with graded concentration of HOASS. Four isonitrogenous and isocaloric diets containing 0, 50, 100, and 200 g HOASS/kg (Table 3) were evaluated for amino acid, crude fat, and fatty acid digestibilities and AMEn value with broilers at approximately 1.5 and 6 wk of age. One hundred forty-four newly hatched Cobb broiler male chicks were randomly distributed in electrically heated battery brooders with 6 birds per cage and 6 cages per dietary treatment. At 21 d of age the birds were transferred to unheated finishing battery brooders. The birds were fed the experimental diets from d 0 to 42. At 12 and 42 d, body weights of individual birds and group feed intakes were recorded. Excreta from each cage were collected during the last 3 d and stored at −20°C. After being thawed, excreta were homogenized, freeze-dried, and ground to pass through a 1-mm screen. Diets and excreta were analyzed for dry matter, CP, amino acids, crude fat, fatty acids, titanium dioxide, and gross energy.

Chemical Analyses Dry matter, CP (N × 6.25), crude fiber, and ash were analyzed according to the methods of the Association of Official Analytical Chemists International (1995). Neutral and acid detergent fibers and acid detergent lignin were determined following the sequential analysis outlined by Robertson and Van Soest (1981). Crude fat was determined by extraction in petroleum ether following acidification with 4 N HCl solution (Wiseman et al., 1992). Titanium dioxide was determined colorimetrically as reported by Short et al. (1996). Gross energy of the samples was measured using an adiabatic bomb calorimeter.4 Fatty acid composition was determined by gas chromatography using pentadecanoic acid5 as the internal standard. The lipid extracts were esterified with a mixture of boron trifluoride (in 10% methanol), hexane, and methanol (35:20:45, vol/vol/vol) (Morrison and Smith, 1964). The resultant fatty acid methyl esters were analyzed on a Chrompack CP 9001 Gas Chromatograph6 equipped with a Chrompak6 CP-Wax 52CB WCOT fused silica capillary column (30 m × 0.32 mm i.d.) and a flame ionization detector. Analyses were performed with a temperature program from 170 to 250°C that increased by 3.5°C/min. The carrier gas was nitrogen at a flow rate of 4.5 mL/min.

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Neutral detergent fiber. Acid detergent fiber. 3 Acid detergent lignin. 4 Not detected. 2

3 d, excreta samples from each cage were collected and stored at −20°C. After being thawed, excreta were homogenized, freeze-dried, and ground through a 1-mm screen. Birds were handled according to the principles for the care of animals in experimentation established by Royal Decree 223/88 of Spain (1988). Experimental procedures were approved by the Complutense University (Madrid) Animal Care and Use Committee. Diets and excreta were analyzed for dry matter, CP, amino acids, titanium dioxide, and gross energy.

397

HIGH-OLEIC SUNFLOWER SEED IN BROILERS DIETS TABLE 2. Composition and nutritive value of basal diet and diets with increasing amounts of high-oleic acid sunflower seed (HOASS), experiment 1 Inclusion (g/kg as fed) Ingredients Ground corn Soybean meal (44% CP) Sunflower oil HOASS Salt Ground limestone Dicalcium phosphate DL-Methionine Titanium dioxide Butylhydroxytoluol Vitamin-mineral premix1 Analyzed nutrient composition Crude protein Lysine Methionine AMEn2 (kcal/kg)

0

80

160

240

320

555.0 340.0 60.0 0.0 3.0 10.0 19.0 2.0 5.0 1.0 5.0

508.6 311.4 55.0 80.0 3.0 10.0 19.0 2.0 5.0 1.0 5.0

462.0 283.0 50.0 160.0 3.0 10.0 19.0 2.0 5.0 1.0 5.0

415.7 254.3 45.0 240.0 3.0 10.0 19.0 2.0 5.0 1.0 5.0

369.3 225.8 39.9 320.0 3.0 10.0 19.0 2.0 5.0 1.0 5.0

210.0 11.6 4.8 3,160

208.1 10.3 5.0 —

208.1 9.8 4.9 —

200.0 9.4 5.1 —

199.4 9.7 5.0 —

Amino acid analysis was by OPA (o-phtaldialdehyde) precolumn derivatization following hydrolysis of samples with 6N HCl at 110°C for 22 h in sealed evacuated tubes. Amino acids were determined using a HPLC system7 equipped with a fluorescence detector according to the procedure of Jones et al. (1981). Cystine and tryptophan were not determined. Digestibility values for glycine were not calculated because they can be erratic as glycine is formed from uric acid (Slump et al., 1977), even during the hydrolysis of excreta samples (Soares et al., 1971). Amino acidic N was estimated as the summation of N contributed by each analyzed amino acid.

Calculations and Statistical Analysis Feed intake was determined as feed intake per cage per number of birds within a cage. Apparent digestibility of nutrients and AME were calculated as follows: digestibility (%) = 100 − [100 × (diet TiO2/excreta TiO2) × (excreta nutrient/diet nutrient)]. ME (kcal/kg) = dietary gross energy × [1 − (diet TiO2/excreta TiO2) × (excreta gross energy/diet gross energy)]. The correction of AME to zero nitrogen retention (AMEn) was based on a factor of 8.22 kcal/g of retained N (Hill and Anderson, 1958).

7

Hewlett-Packard 1100, Agilent Technologies GmbH, Walbronn, Germany.

The AMEn value for HOASS was calculated using the following equation: AMEn = (AMEnT − a × AMEnB)/b, where T is the test diet, a is the proportion of the basal diet (excluding the nonenergy yielding ingredients) in the test diets, B is the basal diet, and b is the proportion of HOASS in the test diets. Statistical analyses were performed by using the GLM procedures of SAS software (SAS Institute, 1990). Data generated from experiment 1 were subjected to ANOVA to identify variation produced by inclusion level of HOASS; regression analysis was also used to establish dietary changes as a function of inclusion level of HOASS. Data derived from the balance trial in experiment 2 were analyzed by 2-factor ANOVA arrangement of treatments (dietary inclusion level of HOASS and age of birds) with a repeated measure on one factor (age). The comparison of means was done by the least significant difference test (Steel and Torrie, 1980).

RESULTS AND DISCUSSION Test Product The nutrient composition of the HOASS used in this study appears in Table 1. The crude fat content (444.3 g/ kg) was within the range reported by Crum et al. (1993) for the high-oil sunflower seed of conventional hybrid varieties. As expected, oleic acid was the major fatty acid, accounting for 80% of the total fatty acid content.

Experiment 1 Table 4 presents AMEn data (kcal/kg) for the experimental diets. Increasing inclusion rate of HOASS increased the AMEn of the diets. To further assess this trend,

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1 Premix provided the following per kilogram of diet: vitamin A, 7,500 IU (retinyl acetate); cholecalciferol, 1,500 IU; vitamin E, 8.0 IU (DL-α-tocopheryl acetate); menadione, 2.5 mg; thiamine, 3 mg; riboflavin, 6 mg; pyridoxine, 7 mg; folic acid, 0.2 mg; cyanocobalamin, 0.02 mg; biotin, 0.2 mg; calcium pantothenate, 25 mg; niacin, 50 mg; choline chloride, 1,300 mg; Mn, 175 mg; Zn, 100 mg; Fe, 75 mg; Cu, 7.5 mg; I, 1.2 mg; Co, 5.0; Mo, 2.2 mg; Se, 0.15 mg. 2 Calculated value.

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TABLE 3. Composition and nutritive value of experimental diets with graded amounts of high-oleic acid sunflower seed (HOASS), experiment 2 Inclusion (g/kg as fed) Ingredients

0

100

200

508.5 387.0 60.0 0.0 3.0 10.0 19.0 1.5 5.0 1.0 5.0

486.9 370.0 48.6 50.0 3.0 10.0 19.0 1.5 5.0 1.0 5.0

463.5 354.8 37.2 100.0 3.0 10.0 19.0 1.5 5.0 1.0 5.0

418.0 322.0 15.5 200.0 3.0 10.0 19.0 1.5 5.0 1.0 5.0

216.5 12.0 4.7

218.4 11.6 4.6

217.2 11.2 4.7

213.6 11.0 4.5

9.8 4.5 28.1 56.0 1.1 3,100

8.7 3.9 34.9 50.8 1.0 3,100

7.8 3.9 48.0 38.8 0.9 3,100

7.0 4.0 63.4 24.0 0.8 3,100

1 Premix provided the following per kilogram of diet: vitamin A, 7,500 IU (retinyl acetate); cholecalciferol, 1,500 IU; vitamin E, 8.0 IU (DL-α-tocopheryl acetate); menadione, 2.5 mg; thiamine, 3 mg; riboflavin, 6 mg; pyridoxine, 7 mg; folic acid, 0.2 mg; cyanocobalamin, 0.02 mg; biotin, 0.2 mg; calcium pantothenate, 25 mg; niacin, 50 mg; choline chloride, 1,300 mg; Mn, 175 mg; Zn, 100 mg; Fe, 75 mg; Cu, 7.5 mg; I, 1.2 mg; Co, 5.0; Mo, 2.2 mg; Se, 0.15 mg. 2 Total fatty acids. 3 Calculated value.

the dietary AMEn values were regressed against the inclusion level of HOASS using linear and quadratic models. The results showed that the linear component was highly significant (P < 0.0001), whereas the quadratic component did not reach a significant level (P = 0.17). This indicated that the energy contribution of HOASS to diets was additive, and the inclusion rate did not alter the use of other dietary ingredients. TABLE 4. Apparent metabolizable energy (AMEn)1 of diets with graded levels of high-oleic acid sunflower seed (HOASS), and of HOASS determined by difference and regression analysis, experiment 1 Level of HOASS (g/kg) 0 80 160 240 320 Pooled SEM

AMEn of diets (kcal/kg)

AMEn of HOASS (kcal/kg)

3,159a 3,237b 3,302b 3,421c 3,496d 24

— 3,860 ± 3692 3,673 ± 116 4,297 ± 94 4,300 ± 92

Values with a common letter do not differ significantly (P < 0.05). AMEn determinations were made based on 30 pens of 2 birds each. 2 Standard error was calculated as a–d 1

1,000/G√VARtd/ntd + F2 VARbd/nbd, where G = g of HOASS/kg, F = proportion of basal in diet containing HOASS, VAR = variance; td = test diet, and bd = basal diet (Wiseman and Lessire, 1987). Linear regression equation: y = 3.151 (±18) + 1.07 (±0.09) x; R2 = 0.832 where y = AMEn (kcal/kg ) and x = dietary inclusion level of HOASS (g/kg).

By using the AMEn values determined for the basal diet and the basal diet containing a given amount of HOASS, the AMEn (kcal/kg) of this feed was calculated by difference (Table 4). The standard errors associated with AMEn values decreased progressively as the amount of HOASS incorporated into the basal diet increased. This finding could be attributed to the fact that small errors made at any stage of a bioassay will be magnified greatly as test ingredient is evaluated at low dietary inclusion levels (Sibbald and Slinger, 1963; Yoshida, 1972; Wiseman et al., 1986). For this reason, it has been argued that a bioassay using only one rate of inclusion is not a satisfactory procedure to determine with confidence the ME values for poultry feed ingredients, and, therefore, multilevel assay and regression analysis have been recommended to obtain more reliable values (Sibbald and Slinger, 1963; Mateos and Sell, 1980; Wiseman and Lessire, 1987). Accordingly, the AMEn values obtained for diets in the experiment reported here were regressed on level of HOASS in the basal diet to estimate the AMEn content in HOASS. The equation derived of fitting a linear model was the following: y = 3,151 (±18) + 1.07 (±0.09)x; R2 = 0.832. An estimate of the AMEn of HOASS was obtained by extrapolation of the equation where 1,000 g/kg HOASS in the diet gave a value of 4,224 ± 77 kcal/kg as fed. The standard error associated with this value was lower than that associated with values determined experimentally by substitution at any inclusion level of HOASS, which indicated that multilevel regression method was better than single-level assay in estimating ME of HOASS. The

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Ground corn Soybean meal (44% CP) Sunflower oil HOASS Salt Ground limestone Dicalcium phosphate DL-Methionine Titanium dioxide Butylhydroxytoluol Vitamin-mineral premix1 Analyzed nutrient composition (g/kg) Crude protein Lysine Methionine Fatty acid content (% of TFA2) C16:0 C18:0 C18:1n-9 C18:2n-6 C18:3n-3 AMEn3 (kcal/kg)

50

399

HIGH-OLEIC SUNFLOWER SEED IN BROILERS DIETS TABLE 5. Productive performance of broilers (0 to 12 d and 0 to 42 d) fed diets with graded levels of high-oleic acid sunflower seed (HOASS), experiment 2 Inclusion (g/kg) 0–12 d Parameter Weight gain (g/bird) Feed intake (g/bird) Feed-to-gain ratio

Statistical significance

0–42 d

0

50

100

200

0

50

100

200

Age (A)

Inclusion (I)

A×I

Pooled SEM

212 298 1.41

211 292 1.39

203 282 1.39

174 277 1.59

2,186 3,721 1.70

2,116 3,620 1.69

2,088 3,662 1.75

1,991 3,618 1.82

*** *** ***

*** NS ***

** NS NS

18.5 32.3 0.03

*P < 0.05, **P < 0.01, ***P < 0.001.

energy value thus obtained for HOASS was slightly lower than the 4,472 kcal of AME/kg of dry matter reported by Rodrı´guez et al. (1998) for a conventional sunflower seed with similar crude fat content (47.3%, dry-matter basis).

The results of experiment 2 on the performance of broilers fed diets with graded concentrations of HOASS are summarized in Table 5. Dietary inclusion of HOASS had an effect (P < 0.001) on BW gain and feed-to-gain ratio. Birds fed the diets containing 100 and 200 g of HOASS/ kg gained less weight and had a poorer feed-to-gain ratio than those fed the diet containing no HOASS. There were no significant differences in intake of any of the diets over the 2 experimental periods. Consequently, because the diets used were formulated to be isocaloric (3,100 kcal/kg) and because dietary energy content is the main factor regulating feed intake (NRC, 1994), the effect observed on BW could be attributed to the composition of the diet and not to the variation in feed intake. This assumption was further supported by the results relating to amino acids and fat digestibilities and ME. Interaction between age and inclusion level was also present for weight gain, probably due to the response to dietary HOASS, which was relatively greater in birds at 12 d than at 42 d of age. The influence of age and diet on amino acid digestibility appears in Table 6. All amino acids determined were better digested (P < 0.001) by 42-d-old birds than by 12-dold birds, and the average apparent digestibility of amino acid N increased from 82.1% at 12 d to 86.7% at 42 d. These results agree with the findings of Wallis and Balnave (1984) who found a positive influence of age on the digestibility of amino acids and with those of Noy and Sklan (1995) who also reported that nitrogen digestibility increased during the first 4 to 21 d after hatch. More recently, Batal and Parsons (2002) have reported that when commercial chicks were fed a corn-soybean meal diet, the digestibility of amino acids increased with age until 21 d. Mechanisms such as increased enzyme secretion to the duodenum, increased absorptive surface per intestine unit, and development of gastrointestinal tract have been proposed to explain the improvement of protein and amino acid digestibilities with chick age. (Uni et al., 1995; Batal and Parsons, 2002).

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Experiment 2

In contrast to these findings, other data available in the literature show that the digestibility of protein and amino acids decreases as the age increases (Ha˚kansson and Eriksson, 1974; Fonolla´ et al., 1981; Hassan and Delpech, 1986; Zuprizal et al., 1992). The reason for these contradictions is unclear, although some of them might be explained, at least in part, by the different methodology used. Carre´e et al. (1991) suggested that, when apparent digestibility is determined, possible differences between the values obtained for young and adult birds could be an artifact because it is unknown whether these differences are a consequence of better use of the dietary protein or of lower endogenous protein loss. As shown in Table 6, the apparent digestibility of 5 out of 14 amino acids was also affected by the concentration of HOASS in the diet. Aspartic acid, threonine, tyrosine, valine, and isoleucine showed significant reductions in digestibility. Likely, the mean digestibility value for diets at both ages decreased by approximately 3% in response to the inclusion of HOASS in the diet. An interaction (age × inclusion level) was observed for aspartic acid (P < 0.01) and threonine (P < 0.05), reflecting a differential trend in the digestibility values to HOASS inclusion at 12 or at 42 d. This adverse effect on the digestibility of amino acids caused by the use of HOASS might be attributable to a substantial increase in the consumption of dietary fiber by birds. Thus, in our experiment, increasing the concentration of HOASS from 0 to 200 g/kg of diet increased the crude fiber content from 3.8 to 6.1%, but the feed intake was not significantly affected. Halvorson et al. (1988) reported that a crude fiber content in diet above 4.63% might be a limiting factor in the ability of broilers to consume enough feed for maximum body gain. Dietary fiber has been shown to influence endogenous N and amino acid excretion in rats, chickens, and piglets (Masson and Palmer, 1973; Parsons et al., 1983; Parsons, 1984). An increase in the intake of fiber can cause increased digestive secretions (Schneeman et al., 1982; Zebrowska et al., 1983), increased bacterial synthesis of amino acids in the hindgut (Masson, 1984), and increased sloughing of cells from the intestinal lining (Beames and Eggun, 1981). These effects could lead to lower estimates of apparent digestibility. Digestibility data of dietary fat are given in Table 7. The apparent digestibility of crude fat, total fatty acids, and major fatty acids was (P < 0.001) higher in 42-d-old birds than in 12-d-old birds, irrespective of the inclusion

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TABLE 6. Apparent digestibility (%) of amino acids of diets with graded levels of high-oleic acid sunflower seed (HOASS) measured at 12 and 42 d of age Inclusion (g/kg) 12 d 0

50

100

200

0

50

100

200

Age (A)

Inclusion (I)

A×I

Pooled SEM

86.1 89.2 80.9 84.6 78.4 76.5 85.8 81.2 83.0 82.6 85.8 84.5 85.3 86.0 83.0

85.7 89.3 81.6 85.4 77.7 77.3 86.4 81.6 83.0 82.6 85.8 84.1 86.0 87.9 83.4

84.1 88.6 80.5 83.4 75.8 76.2 85.4 80.7 82.0 81.7 85.3 82.7 85.3 87.9 81.9

81.2 87.6 78.3 81.7 73.4 74.2 84.8 77.2 78.2 79.0 83.4 80.5 83.8 85.4 79.9

87.6 91.4 87.6 91.4 85.9 84.6 91.7 91.0 87.6 94.0 90.5 89.2 90.0 90.4 87.6

87.5 90.7 86.0 90.6 84.8 83.2 90.8 89.0 87.1 92.0 89.8 88.4 89.0 90.4 86.0

87.5 91.3 87.1 92.5 86.1 84.2 91.6 90.8 88.3 94.3 91.3 88.8 89.8 91.3 87.6

86.6 90.9 86.0 90.4 84.1 82.8 90.7 88.8 86.7 92.8 89.9 88.1 88.8 90.5 85.7

*** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

*** NS NS NS *** NS NS * * NS NS * NS NS *

** NS NS NS * NS NS NS NS NS NS NS NS NS NS

0.63 0.45 0.93 0.87 0.69 0.79 0.93 0.95 0.99 1.06 0.90 0.92 0.62 0.80 0.77

Amino acid Aspartic acid Glutamic acid Serine Histidine Threonine Alanine Arginine Tyrosine Valine Methionine Phenylalanine Isoleucine Leucine Lysine Amino acid N

Statistical significance

42 d

*P < 0.05, **P < 0.01, ***P < 0.001.

digestibility values were also influenced by the inclusion level of HOASS. The apparent digestibility of crude fat and total fatty acids decreased as HOASS proportion in the diet increased. The magnitudes of decrease for crude fat and total fatty acid digestibility were approximately 12 and 11% at 12 d and 5 and 7% at 42 d, respectively. The digestibility values for oleic acid, the major fatty acid in HOASS oil (80.7% of the total fatty acids), followed a similar pattern with the rate of inclusion of HOASS to that observed for crude fat and fatty acid digestibility values. Linoleic acid appeared to be the best absorbed fatty acid, but differences with oleic acid were smaller than those reported by Vila´ and Esteve-Garcı´a (1996) for refined sunflower oil. In contrast, stearic acid had the lowest digestibility, which agreed with the findings of Lessire et al. (1982) who reported that digestibility increases with unsaturation for C18 fatty acids with tallow fed to poultry. Digestibility values for linolenic acid were rather erratic due to its low concentration in the diets. Interactions between age and inclusion level were not present, which suggests that the responses in digestibility

TABLE 7. Apparent digestibility (%) of crude fat and fatty acids and AMEn of diets with graded levels of high-oleic acid sunflower seed (HOASS) measured at 12 and 42 d of age Inclusion (g/kg) 12 d

Crude fat Fatty acid C16:0 C18:0 C18:1n-9 C18:2n-6 C18:3n-3 TFA1 AMEn (kcal/kg as fed) 1

0

50

67.8

64.0

63.6

68.2 41.8 68.6 77.5 76.6 71.6 3,006

67.9 43.0 65.7 77.7 77.0 70.4 2,955

65.0 32.7 64.9 74.2 74.6 66.4 2,840

Total fatty acids. *P < 0.05; **P < 0.01; ***P < 0.001.

Statistical significance

42 d 100

200

0

50

100

59.8

84.8

80.2

82.7

64.9 43.6 62.9 73.7 77.5 63.7 2,779

84.4 85.1 89.0 90.7 83.5 89.1 3,085

80.2 74.9 80.4 87.5 80.5 83.3 3,052

82.4 76.2 79.8 88.6 83.5 83.6 3,064

Age (A)

Inclusion (I)

A×I

Pooled SEM

80.1

***

**

NS

1.77

81.9 75.4 82.0 85.5 84.0 82.7 3,109

*** *** *** *** *** *** ***

NS NS ** * NS ** ***

NS NS NS NS NS NS **

1.66 3.69 1.94 1.49 1.23 1.77 31.5

200

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level of HOASS. The mean digestibility of crude fat and total fatty acids for diets increased by approximately 28 and 24%, respectively, between 12 and 42 d of age. Stearic acid showed the highest (93%) and linoleic acid the lowest (16%) increments in digestibility with age. This effect of age on the digestibility of fat found in the current study agrees with earlier findings indicating that fat digestion increased during the initial weeks after hatching when saturated fats or high-fat diets are fed (Carew et al., 1972; Go´mez and Polin, 1976; Wiseman and Salvador, 1989). Low digestibility values for fat in very young chicks have been attributed to limited lipase activity (Krogdahl, 1985; Dunnington and Siegel, 1995) and an inhability to replace bile salts lost by excretion as readily as older birds (Go´mez and Polin, 1976). In contrast, a few reports point to little or no change in fat digestion with age. For instance, Lessire et al. (1982) did not find any conclusive evidence of improvements in fat digestion between birds aged 2 and 6 wk. More recently, Noy and Sklan (1995) observed that digestion of fatty acids hardly changed between 4 and 21 d of age. In our experiment, dietary fat

HIGH-OLEIC SUNFLOWER SEED IN BROILERS DIETS

ACKNOWLEDGMENTS This study was supported by Grant AGL 2001-1116 from the Comisio´n Interministerial de Ciencia y Tecnologı´a, Spain. The authors thank KOIPE SA (Andu´jar, Jae´n, Spain) for supplying the high-oleic acid sunflower seed used in this study. Special thanks are also extended to Ricardo Garcı´a Mata of the Servicio de Apoyo a la Investigacio´n y la Docencia (UCM) for the statistical analysis of the data.

REFERENCES Association of Official Analytical Chemists International. 1995. Official Methods of Analysis. AOAC, Arlington, VA. Batal, A. B., and C. M. Parsons. 2002. Effect of age on nutrient digestibility in chicks fed different diets. Poult. Sci. 81:400– 407. Beames, R. M., and B. O. Eggun. 1981. The effect of type and level of protein, fibre and starch on nitrogen excretion patterns in rats. Br. J. Nutr. 46:301–313.

Carre´e, B., E. Beaufils, and J. P. Melcion. 1991. Evaluation of protein and starch digestibilities and energy value of pelleted or unpelleted pea seeds from winter or spring cultivars in adult and young chickens. J. Agric. Food Chem. 39:468–472. Cheva-Isarakul, B., and S. Tangtaweewipat. 1991. Effect of different levels of sunflower seed in broiler rations. Poult. Sci. 70:2284–2294. Carew, L. D., R. H. Macheme, R. W. Sharp, and D. C. Foss. 1972. Fat absorption by the very young chick. Poult. Sci. 51:738–742. Crum, C. W., J. M. Prescott, and P. J. Christensen. 1993. Genetic approaches to increased nutritional value in oilseed meal. Pages 334–338 in Proceedings of the World Conference on Oilseed Technology and Utilization. T. H. Appelwhite, ed. AOAC Press, Champaign, IL. Dunnington, E. A., and P. B. Siegel. 1995. Enzyme activity and organ development in newly hatched chicks selected for high or low eight-week body weight. Poult. Sci. 74:761–770. Fonolla´, J., C. Prieto, and R. Sanz. 1981. Influence of age on the nutrient utilization of diets for broilers. Anim. Feed Sci. Technol. 6:405–411. Go´mez, M., and D. Polin. 1976. The use of bile salts to improve absorption of tallow in chicks 1 to 3 weeks of age. Poult. Sci. 55:2189–2195. Grundy, S. M. 1986. Comparison of monounsaturated fatty acids and carbohydrates for lowering plasma cholesterol. N. Engl. J. Med. 314:745–748. Ha˚kansson, J., and S. Eriksson. 1974. Digestibility, nitrogen retention and consumption of metabolizable energy by chickens on feeds of low and high concentration. Swed. J. Agric. Res. 4:195–207. Halvorson, J. C., P. E. Waibel, and M. A. Shehata. 1988. Effects of white lupin in diets of growing turkeys. Poult. Sci. 67:596–607. Hassan, A. S., and P. Delpech. 1986. Metabolizable energy value and protein digestibility in chickens: Influence of genotype, age and diet. Genet. Sel. Evol. 18:225–236. Hill, F. W., and D. N. Anderson. 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutr. 64:587–603. Jones, B. N., S. Pa¨abo, and S. Stein. 1981. Amino acid analysis and enzymatic sequence determination of peptides by an improved o-phthaldialdehyde precolumn labeling procedure. J. Liquid Chromatogr. 4:565–586. ˚ . 1985. Digestion and absorption of lipids in poultry. Krogdahl, A J. Nutr. 115:675–685. Lessire, N., B. Leclerq, and L. Conan. 1982. Metabolisable energy value of fats in chicks and adult cockerels. Anim. Feed Sci. Technol. 73:365–374. Masson, V. C. 1984. Metabolism of nitrogenous compounds in the large gut. Proc. Nutr. Soc. 43:45–53. Masson, V. C., and R. Palmer. 1973. The influence of bacterial activity in the alimentary canal of rats on fecal nitrogen excretion. Acta Agric. Scand. 23:141–150. Mateos, G. G., and J. L. Sell. 1980. True and apparent metabolizable energy value of fat for laying hens: influence of level of use. Poult. Sci. 59:369–373. Morrison, W. R., and M. L. Smith. 1964. Preparations of fatty acid methyl esters and dimethylacetals from lipid with boron fluoride methanol. J. Lipid Res. 5:600–608. National Research Council. 1994. Nutrient Requirements of Poultry. National Academy Press, Washington, DC. Noy, Y., and D. Sklan. 1995. Digestion and absorption in the young chicks. Poult. Sci. 74:366–373. Ortiz, L. T., A. Rebole´, M. L. Rodrı´guez, J. Trevin˜o, C. Alzueta, and B. Isabel. 1998. Effect of chicken age on the nutritive value of diets with graded additions of full-fat sunflower seed. Br. Poult. Sci. 39:530–535. Parsons, C. M. 1984. Influence of caecectomy and source of dietary fiber or starch on excretion of endogenous amino acids by laying hens. Br. J. Nutr. 51:541–548.

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values for fat and fatty acids to HOASS concentration in the diet were essentially independent of age of birds Dietary AMEn data (kcal/kg as fed) are also shown in Table 7. ANOVA revealed an effect (P < 0.001) of age, a higher AMEn value for each diet being found when measured with 42-d-old birds than with 12-d-old birds. Based on the mean for all diets, the AMEn value increased by approximately 6% between both ages. This finding agreed with the generally accepted idea that AMEn tends to increase at older ages (Zelenka, 1968; Sibbald, 1982; Batal and Parsons, 2002). In the present study, increase of dietary AMEn with age was probably due to a combination of improved use of the fat and protein because the digestibility of both nutrients increased with age. In addition, a possible improvement in the use of the dietary starch might have contributed to this positive effect of age on the AMEn (Batal and Parsons, 2002). The results of ANOVA also indicated that the dietary AMEn value was affected by the inclusion level of HOASS. Because the interaction of age × inclusion level was present (P < 0.01), data for each age were analyzed separately. In birds at 12 d, increasing the concentration of HOASS resulted in a progressive reduction in the AMEn content from 3,006 (0 g of HOASS/kg) to 2,779 (200 g of HOASS/kg) kcal/ kg. In older birds (42 d), AMEn values did not significantly differ among diets. In conclusion, the results from the current experiments indicated that multilevel regression procedure is more appropriate than single-level assay for estimating the ME of HOASS. The substitution of HOASS for corn, soybean meal, and refined sunflower oil up to 200 g/kg of diet did not have any adverse effect on the performance of young (12 d) or older (42 d) birds. Apparent digestibility of dietary fat and major fatty acids was negatively affected by the inclusion rate of HOASS. Amino acids and fat digestibilities and dietary AMEn were influenced by bird age. It could also be deduced that different ME values for HOASS should be used for young and older broilers.

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RODRI´GUEZ ET AL. Soares, J. H., D. Miller, N. Fitz, and M. Sanders. 1971. Some factors affecting the biological availability of amino acids in fish protein. Poult. Sci. 50:1134–1143. Steel, R. G. D., and J. H. Torrie. 1980. Principles and Procedures of Statistics. A Biometral Approach. 2nd ed. McGraw-Hill, New York. Uni, Z., Y. Noy, and D. Sklan. 1995. Post-hatch changes in morphology and function of the small intestines in heavy and light-strain chicks. Poult. Sci. 74:1622–1629. Vila´, B., and E. Esteve-Garcı´a. 1996. Studies on acid oils and fatty acids for chickens. III. Effect of chemical composition on metabolisable energy of by-products of vegetable oil refining. Br. Poult. Sci. 37:131–144. Wallis, I. R., and D. Balnave. 1984. The influence of environmental temperature, age and sex on the digestibility of amino acids in growing broiler chickens. Br. Poult. Sci. 25:401–407. Wiseman, J., D. J. A. Cole, F. G. Perry, B. G. Vernon, and B. C. Cooke. 1986. Apparent metabolisable energy values of fats for broiler chicks. Br. Poult. Sci. 27:561–576. Wiseman, J., B. K. Edmunds, and N. Shepperson. 1992. The apparent metabolizable energy of sunflower oil and sunflower acid oil for broiler chickens. Anim. Feed Sci. Technol. 36:41–51. Wiseman, J., and M. Lessire. 1987. Interactions between fats of differing chemical content: Apparent metabolisable energy values of fats for broiler chicks. Br. Poult. Sci. 28:663–676. Wiseman, J., and F. Salvador. 1989. Influence of age, chemical composition and rate of inclusion on the apparent metabolisable energy of fats fed to broiler chicks. Br. Poult. Sci. 30:653–662. Yoshida, M. 1972. Evaluation of error of variance of metabolizable energy of feed ingredient. Jpn. Poult. Sci. 9:281–285. Zebrowska, T., A. G. Lou, and H. Zebrowska. 1983. Studies on gastric digestion of protein and carbohydrate, gastric secretion and exocrine pancreatic secretion in the growing pig. Br. J. Nutr. 49:401–410. Zelenka, J. 1968. Influence of the age of the chicken on the metabolisable energy values of poultry diets. Br. Poult. Sci. 32:135–142. Zollitsh, W., W. Knaus, F. Aichinger, and F. Lettner. 1997. Effects of different dietary fat sources on performance and carcass characteristics of broilers. Anim. Feed Sci. Technol. 66:63–73. Zuprizal, L., M. Larbier, and A. E. Chagneau. 1992. Effect of age and sex on true digestibility of amino acids of rapeseed and soybean meals in growing broilers. Poult. Sci. 71:1486–1492.

Downloaded from http://ps.oxfordjournals.org/ by guest on March 25, 2015

Parsons, C. M., L. M. Potter, and R. D. J. R. Brown. 1983. Effects of dietary carbohydrate and of intestinal microflora on excretion of endogenous amino acids by poultry. Poult. Sci. 62:483–489. Robertson, J. B., and P. J. Van Soest. 1981. The detergent system of analysis and its application in human foods. Pages 123– 158 in The Analysis of Dietary Fiber in Food. W. P. T. James and O. Theander, ed. Marcel Dekker, New York. Roche, H. M. 2001. Olive oil, high-oleic acid sunflower oil and CHD. Br. J. Nutr. 85:3–4. Rodrı´guez, M. L., L. T. Ortiz, J. Trevin˜o, A. Rebole´, C. Alzueta, and C. Centeno. 1998. Studies on the nutritive value of fullfat sunflower seed in broiler chick diets. Anim. Feed Sci. Technol. 71:341–349. Roth-Maier, D. A., K. Eder, and M. Kirchgessner. 1998. Live performance and fatty acid composition of meat in broiler chickens fed diets with various amounts of ground or whole flaxseed. J. Anim. Physiol. Anim. Nutr. 79:260–268. Royal Decree 223/88 of Spain. 1988. Sobre proteccio´n de los animales utilizados en experimentacio´n y otros fines cientıficos. BOE 67:8509–8511. ´ Sanz, M., A. Flores, and C. J. Lo´pez-Bote. 1999. Effect of fatty acid saturation in broiler diets on abdominal fat and breast muscle fatty acid composition and susceptibility to lipid oxidation. Poult. Sci. 78:378–382. SAS Institute. 1990. SAS Stat User’s Guide Release 6.08. SAS Institute Inc., Cary, NC. Schneeman, B. O., B. D. Richter, and L. R. Jacbons. 1982. Response to the dietary wheat bran in the exocrine pancreas and intestine of rats. J. Nutr. 112:283–286. Short, F. J., P. Gorton, J. Wiseman, and N. K. Boorman. 1996. Determination of titanium dioxide added as an inert marker in chicken digestibility studies. Anim. Feed Sci. Technol. 59:215–221. Sibbald, I. R. 1982. Measurement of bioavailable energy in poultry feeding stuffs: a review. Can. J. Anim. Sci. 62:983–1048. Sibbald, S. R., and S. J. Slinger. 1963. A biological assay for metabolizable energy in poultry feed ingredients together with findings which demonstrated some of the problems associated with the evaluation of fat. Poult. Sci. 42:313–325. Slump, P., L. Van Beek, W. M. M. A. Janssen, K. Terpstra, N. P. Lenis, and B. Smits. 1977. A comparative study with pigs, poultry and rats of the amino acid digestibility of diets containing crude protein with diverging digestibilities. Z. Tierphysiol. Tiererna¨hr. Futtermittelkd. 39:257–272.