Performance and tissue fatty acid profile of broiler chickens and laying hens fed hemp oil and HempOmegaTM

Performance and tissue fatty acid profile of broiler chickens and laying hens fed hemp oil and HempOmegaTM M. Jing,∗ S. Zhao,∗ and J. D. House∗,†,1 ∗

Department of Human Nutritional Sciences; and † Department of Animal Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada either HO or HΩ diets had greater total n-3 polyunsaturated fatty acids (PUFAs), alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in egg yolks, thighs, and breasts compared to the control diet (P < 0.01), and monounsaturated fatty acids (MUFAs) content of egg yolks and thighs decreased (P < 0.05). The levels of total n-6 PUFAs, linoleic acid (LA), or arachidonic acid (ARA) of the egg yolk and meat were generally not affected by dietary supplementation with HO or HΩ, but gamma-linolenic acid (GLA) was notably increased (P < 0.01). The current data show that inclusion of hemp oil up to 8% in layer diets and 6% in broiler diets provided by HO or HΩ does not negatively affect overall performance of birds and results in the enrichment of n-3 PUFAs and GLA in eggs and meat.

ABSTRACT This study was conducted to determine the effects of hemp oil (HO) and HempOmega (HΩ), an equivalent product to HO, on performance and tissue fatty acid profile of layers and broiler chickens in two separate experiments. In the first experiment, forty 19wk old Lohmann white laying hens were randomized to 1 of 5 dietary treatments, either a control diet or a control diet supplemented with 4 or 8% hemp oil provided by HO or HΩ, for a period of 6 wk (n = 8/diet). In experiment 2, 150-day-old mixed-sex (75 male; 75 female) Ross 308 chicks were randomly allocated into 5 dietary treatments, a control diet or a control diet supplemented with either 3 or 6% hemp oil provided by HO or HΩ, each with six replicates of 5 chicks for a 21-d feeding period. Performance of layers and broilers was not affected by dietary treatments. Animals provided with

Key words: hemp products, performance, n-3 fatty acids, broiler chicken, laying hen 2017 Poultry Science 0:1–11 http://dx.doi.org/10.3382/ps/pew476

INTRODUCTION

studies have demonstrated the beneficial effect of plant oil supplements on the fatty acid composition of poultry meat and eggs (Gonz´alez-Esquerra and Leeson, 2001; L´opez-Ferrer et al., 2001; Fraeye et al., 2012; Pietras and Orczewska-Dudek, 2013). Another oilseed plant, hemp (Cannabis sativa L.) is receiving renewed interest in agriculture and the industry. The commercial production of industrial hemp in Canada was permitted in 1998 following a long period of discontinuation due to the presence of Δ-9 tetrahydrocannabinol (THC), a psychoactive substance in the hemp plant (Health Canada, 2012), nonetheless, hemp products including whole hemp seed, hemp seed oil, and hemp seed meal/cake are not registered as approved feed ingredients for livestock and poultry in Canada due to lack of evidence of safety and efficacy. With respect to nutritional value of hemp, whole hemp seed contains approximately 24% CP and 33% to 35% oil (Callaway, 2004; House et al., 2010). Hemp seed oil or hemp oil (HO) contains 75% to 80% PUFAs, approximately 60% linoleic acid (LA) and 19% ALA, making it a rich and balanced source of n-6 and n-3 PUFAs (Parker et al., 2003). HO also contains approximately 4% gamma-linolenic acid (GLA), a unique n-6 fatty acid that serves as an intermediate for the formation of

Polyunsaturated fatty acids (PUFAs), particularly the n-3 (omega-3) series, including alpha-linolenic acid (ALA), as well as its long-chain (LC) derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential nutrients and necessary for the optimal health of humans and other animals. Studies in humans have demonstrated their health-promoting effects, including reducing the risk of cardiovascular disease, diabetes, neurological disorders, inflammation, autoimmune disorders, and cancer, as well as improving brain and visual development (Plourde and Cunnane, 2007; Russo, 2009). The increasing interest in n-3 fatty acids for human health and well-being has led to research that has explored opportunities to increase n-3 content in meat, eggs, and milk through feeding animals n-3 rich diets. Good sources of n-3 PUFAs used in animal feeding are oilseeds and oils from oilseeds which typically include flax and canola. Many  C 2017 Poultry Science Association Inc. Received September 9, 2016. Accepted December 8, 2016. 1 Corresponding author: j [email protected]

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JING ET AL.

anti-inflammatory eicosanoids, which may have similar anti-inflammatory and anti-proliferative properties as EPA and DHA (Fan and Chapkin, 1998; Leizer et al., 2000; Kapoor and Huang, 2006). The favorable composition of HO provides evidence that it may represent a potentially valuable feed ingredient for poultry. The previous work of our research team investigated the use of HO in diets for laying hens (Gakhar et al., 2012; Goldberg et al., 2012; Neijat et al., 2014), however, to date there is a lack of information regarding the efficacy of HO in the diet of broiler chickens. The current study was designed to examine the effect of including HO in diets for both laying hens and broiler chickens on the production performance and fatty acid profile of egg yolks and muscle tissues. A secondary objective of the study was to compare the effectiveness of HO and HempOmega (HΩ), a commercial feed product containing hemp oil, offered by Boreal Technologies. To achieve these objectives two separate experiments involving laying hens and broiler chickens were conducted. The results from this study will provide data on safety and efficacy claims for hemp products as feed ingredients in poultry rations.

MATERIALS AND METHODS Birds and Housing The birds were managed in accordance with recommendations established by the Canadian Council on Animal Care (CCAC, 1993) following an animal care protocol approved from the University of Manitoba’s Animal Care Protocol Management and Review Committee.

Experiment 1. Performance and Egg Yolk Fatty Acid Profile of Laying Hens Fed HO and H Forty 19-wk old Lohmann white laying hens procured from a commercial supplier (ISA, Hendrix Genetics, Lockport, MB, Canada) were individually placed in metabolic cages that provided a floor space of 1,032 cm2 (25.4 cm × 40.6 cm) per hen and a perch. Hens were housed under semi-controlled environmental conditions and exposed to a 16-h photoperiod throughout the course of the study. Hens were allowed a period of 2 wk to adapt to their individual cages. Feed and water were available to permit ad libitum consumption.

Experiment 2. Performance and Meat Fatty Acid Profile of Broilers Fed HO and H A total of 150-day-old (75 male; 75 female) Ross 308 broiler chicks were obtained from a local hatchery (Carlton Hatchery, Grunthal, MB, Canada) and placed in 30 cages or pens (5 chicks/cage; 15 cages/sex) in

electrically heated Petersime battery brooders (Petersime Incubator Company, Gettysburg, OH). The cage dimension is 98 cm deep × 68 cm wide × 37 cm high. The brooder and room temperatures were set at 32 and 29◦ C, respectively, during the first week. Thereafter, heat supply in the brooder was switched off and room temperature was maintained at 29◦ C throughout the course of the experiment. Birds had ad libitum access to feed and water during the experimental period and light was provided for 24 h.

Diets and Experimental Approach HO and HΩ were sourced through Hemp Oil Canada (St. Agathe, MB, Canada) and Boreal Technologies (University of British Columbia, Vancouver, BC, Canada), respectively. The composition of the HO used for the formulation of diets was based on certificate of analysis received from a commercial laboratory (Norwest Labs, Lethbridge, AB, Canada), which was provided previously by Gakhar et al. (2012). HΩ is a dry powder preparation of hemp oil (sourced from high quality, non-GMO seeds) encapsulated in a lecithin and starch matrix. HΩ was analyzed for CP (1.57% as is basis) using a Leco NS-2000 Nitrogen Analyzer (Leco Corp., St. Joseph, MI), CF (26.9% as is basis) according to the method of AOAC (1990; method 920.39), and DM (95%) according to the method of AOAC (1990; method 925.09). As hemp oil is the only source for CF, 26.9% was the content of hemp oil in HΩ, which was used for the formulation of diets, in order to make the level of hemp oil consistent among the HO and HΩ treatments. The supplementation amounts of HΩ in the layer diets and broiler diets were specifically stated below. Also, for the purpose of achieving same level of hemp oil and similar contents of AMEn, crude fat, and crude protein, the contents of some ingredients varied from diet to diet in the laying hen study and broiler study.

Experiment 1. Performance and Egg Yolk Fatty Acid Profile of Laying Hens Fed HO and H Diets, based on wheat, barley and soybean meal, were formulated to meet or exceed the recommendations for Lohmann laying hens (NRC, 1994; Table 1) consuming 100 g of feed/per day. All treatment diets were designed to be isonitrogenous and isoenergtic, providing 10% crude fat, in order to match the crude fat content associated with the highest inclusion rate of HO or HΩ tested (8%). The 5 dietary treatments (8 hens/treatment) were: 1) Control diet with no supplemented HO or HΩ; 2) Control diet + 4% HO; 3) Control diet + 8% HO; 4) Control diet + 4% HΩ; 5) Control diet + 8% HΩ. 4% HΩ and 8% HΩ were equivalents for 4% HO and 8% HO, and their supplementation percentages were 14.88% and 29.76%,

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DIETARY HEMP OIL AND POULTRY PERFORMANCE Table 1. Composition and nutrient content of the diets for laying hens. Control

4% HO

8% HO

4% HΩ2

8% HΩ2

34.46 18.39 23.48 8.57 1.75 0.71 10.77 1.60 0.10 0.17 0.00 0.00 0.00 100.0

34.46 18.39 23.48 4.57 1.75 0.71 10.77 1.60 0.10 0.17 4.00 0.00 0.00 100.0

34.46 18.39 23.48 0.57 1.75 0.71 10.77 1.60 0.10 0.17 8.00 0.00 0.00 100.0

33.98 27.62 0.00 5.13 1.75 0.73 10.72 1.62 0.00 0.17 0.00 14.88 3.40 100.0

12.12 32.14 0.00 1.51 1.75 0.78 10.65 1.70 0.00 0.18 0.00 29.76 9.43 100.0

Nutrient content (calculated unless noted) AMEn (poultry; kcal/kg) 2800 2800 2800 Gross energy (analyzed, kcal/kg) 3,738.14 3,795.76 3,690.87 Crude fat (%) 10.00 10.00 10.00 Crude fat (analyzed, %) 9.11 9.34 9.18 CP (%) 17.00 17.00 17.00 CP (analyzed, %) 16.77 16.91 16.61 Total lysine (%) 0.82 0.82 0.82 Total methionine (%) 0.41 0.41 0.41 Total threonine (%) 0.57 0.57 0.57 Calcium (%) 4.30 4.30 4.30 Calcium (analyzed, %) 4.34 4.33 4.29 Total phosphorus (%) 0.65 0.65 0.65 Total phosphorus (analyzed, %) 0.67 0.67 0.62 Available phosphorus (%) 0.44 0.44 0.44 Sodium (%) 0.31 0.31 0.31 Chloride (%) 0.50 0.50 0.50 Linoleic acid (%) 5.21 5.11 5.00 α -Linolenic acid (%) 0.15 0.77 1.39

2800 3,805.18 10.00 9.15 17.00 16.98 0.88 0.41 0.64 4.30 4.31 0.63 0.67 0.44 0.31 0.50 5.29 0.77

2800 3,818.55 10.00 9.12 17.00 16.80 0.82 0.41 0.57 4.00 4.25 0.63 0.66 0.44 0.18 0.18 2.20 0.00

0.05 7.22 0.07 1.58 13.64 40.34 1.30 6.45 ND 0.03 ND ND

0.05 6.91 0.08 2.25 11.30 50.52 3.04 13.78 ND 0.03 ND ND

Ingredients (%) Barley Soybean meal Wheat Corn oil Vitamin-mineral premix1 Sodium chloride Limestone Dicalcium phosphate L-lysine-HCl DL-methionine Hemp oil HempOmegaTM Cellulose Total

Dietary fatty acid composition (analyzed, mg/g of diet) Myristic (C14:0) 0.05 0.05 0.05 Palmitic (C16:0) 8.89 7.24 5.65 Palmitoleic (C16:1) 0.07 0.07 0.07 Stearic (C18:0) 1.25 1.47 1.65 Oleic (C18:1) 18.62 13.33 8.37 Linoleic (C18:2n-6) 40.34 39.58 38.86 γ -Linolenic (C18:3n-6) ND 1.21 2.33 α -Linolenic (C18:3n-3) 1.09 6.00 10.55 Arachidonic (C20:4n-6) ND ND ND Eicosapentaenoic (C20:5n-3) 0.04 0.03 0.03 Docosapentaenoic (C22:5n-3) ND ND ND Docosahexaenoic (C22:6n-3) ND ND ND

HO: hemp oil; HΩ: HempOmegaTM . ND: not detected. 1 Provided per kg of diet: 11,000 IU of vitamin A, 3,000 IU of vitamin D3 , 150 IU of vitamin E, 3.0 mg of vitamin K3 (as menadione), 0.02 mg of vitamin B12 , 6.5 mg of riboflavin, 4.0 mg of folic acid, 10.0 mg of calcium pentothenate, 40.1 mg of niacin, 0.2 mg of biotin, 2.2 mg of thiamine, 4.5 mg of pyridoxine, 1,000 mg of choline, 125 mg of ethoxyquin (antioxidant), 66 mg of Mn (as manganese oxide), 70 mg of Zn (as zinc oxide), 80 mg of Fe (as ferrous sulfate), 10 mg of Cu (as copper sulfate), 0.3 mg of Se (as sodium selenite), and 0.4 mg of I (as calcium iodate). 2 4% HΩ and 8% HΩ were equivalents for 4% HO and 8% HO, and their supplementation percentages were 14.88% and 29.76% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

respectively. Diets were mixed immediately before the commencement of the study, and stored in a cool, dry storage room. After a 2-wk adaptation period feeding a commercial layer diet during the first week followed by a 50:50 blend of the commercial and experimental diets in the second week, the hens were fed the experimental diets for 6 wk. At the end of each week, total feed consumption was determined as the difference between feed offered and residual feed remaining in feeders, and feed consumption for each bird was cal-

culated for average daily feed intake. Egg weight and egg production were recorded on a daily basis, and hen body weights were measured weekly. The feed conversion ratio (FCR) was calculated as grams of feed consumed per gram of egg produced. During the final week of the experiment, eggs were collected for the last 3 consecutive days from all the birds for egg yolk fatty acid analysis. The egg yolks were separated using an egg yolk separator and stored at −20◦ C until analyzed.

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JING ET AL. Table 2. Composition and nutrient content of the starter-grower diets for broiler chickens. 3% HΩ3

6% HΩ3

65.93 65.93 65.17 48.32 22.22 22.22 22.92 32.97 1.00 1.00 1.00 1.00 0.50 0.50 0.50 0.50 5.91 2.91 0.00 3.10 1.87 1.87 1.87 1.52 0.14 0.14 0.14 0.15 1.76 1.76 1.75 1.67 0.39 0.39 0.37 0.15 0.15 0.15 0.14 0.13 0.15 0.15 0.14 0.04 0.00 3.00 6.00 0.00 0.00 0.00 0.00 10.45 0.00 0.00 0.00 0.00 100.00 100.00 100.00 100.00 Nutrient content (calculated unless noted) AMEn (poultry; kcal/kg) 3,150.00 3,150.00 3,150.00 3,150.00 Gross energy (analyzed, kcal/kg) 4,188.85 4,097.85 4,102.24 4,078.59 Crude fat (%) 8.00 8.00 8.09 8.00 Crude fat (analyzed, %) 7.35 6.68 6.48 7.39 CP (%) 22.97 22.97 23.12 24.42 CP (analyzed, %) 22.81 23.01 22.70 24.07 Total lysine (%) 1.40 1.40 1.40 1.40 Total methionine (%) 0.50 0.50 0.50 0.50 Total threonine (%) 0.90 0.90 0.90 0.90 Calcium (%) 1.05 1.05 1.05 1.05 Calcium (analyzed, %) 0.96 1.00 0.91 1.02 Total phosphorus (%) 0.86 0.86 0.86 0.87 Total phosphorus (analyzed, %) 0.80 0.83 0.90 0.88 Available phosphorus (%) 0.50 0.50 0.50 0.50 Sodium (%) 0.25 0.25 0.25 0.25 Chloride (%) 0.38 0.38 0.38 0.38 Linoleic acid (%) 3.77 3.70 3.67 3.64 α -Linolenic acid (%) 0.09 0.56 1.03 0.53 Dietary fatty acid composition (analyzed, mg/g of diet) Myristic (C14:0) 0.03 0.03 0.03 0.04 Palmitic (C16:0) 7.49 6.71 5.21 7.14 Palmitoleic (C16:1) 0.08 0.08 0.08 0.09 Stearic (C18:0) 1.17 1.37 1.48 1.67 Oleic (C18:1) 18.14 11.71 6.71 12.62 Linoleic (C18:2n-6) 34.03 36.97 35.55 41.81 γ -Linolenic (C18:3n-6) ND 1.11 2.08 1.50 α -Linolenic (C18:3n-3) 1.87 5.80 9.77 7.59 Arachidonic (C20:4n-6) ND ND ND ND Eicosapentaenoic (C20:5n-3) ND 0.01 0.01 0.01 Docosapentaenoic (C22:5n-3) ND ND ND ND Docosahexaenoic (C22:6n-3) ND ND ND ND

32.88 40.52 1.00 0.50 0.31 1.06 0.16 1.86 0.01 0.12 0.00 0.00 20.90 0.67 100.00

Ingredients (%)

Control

Wheat Soybean meal Vitamin premix1 Mineral premix2 Corn oil Limestone Sodium chloride Biophos L-lysine-HCl DL-methionine L-threonine Hemp oil HempOmegaTM Cellulose Total

3% HO

6% HO

3,150.00 4,144.36 8.00 7.02 25.00 24.60 1.40 0.50 0.92 1.05 1.08 0.92 0.89 0.55 0.25 0.39 3.51 0.96 0.04 6.70 0.11 2.11 9.06 47.76 2.88 13.44 ND 0.01 ND ND

HO: hemp oil; HΩ: HempOmegaTM . ND: not detected. 1 Provided per kg of diet: 8,250 IU of vitamin A, 3,000 IU of vitamin D3 , 30 IU of vitamin E, 2.0 mg of vitamin K3 (as menadione), 0.02 mg of vitamin B12 , 6.0 mg of riboflavin, 4.0 mg of folic acid, 11.0 mg of calcium pantothenate, 40.3 mg of niacin, 0.25 mg of biotin, 4.0 mg of thiamine, 4.0 mg of pyridoxine, 1,081 mg of choline, 125 mg of Endox (antioxidant). 2 Provided per kg of diet: 70 mg of Mn (as manganese oxide), 80 mg of Zn (as zinc oxide), 80 mg of Fe (as ferrous sulfate), 10 mg of Cu (as copper sulfate), 0.3 mg of Se (as sodium selenite), and 0.5 mg of I (as calcium iodate). 3 3% HΩ and 6% HΩ were equivalents for 3% HO and 6% HO, and their supplementation percentages were 10.45% and 20.90% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

Experiment 2. Performance and Meat Fatty Acid Profile of Broilers Fed HO and H Five chicks allotted per cage or pen constituted an experimental replicate. The replicates were randomly assigned to the five dietary treatments (6 replicates/treatment; 3 replicates of each sex for per treatment). Five diets, wheat-soybean meal based, were formulated to meet or exceed the National Research Council (NRC) recommendations for growth phases

(starter-grower) of Ross strain (Table 2). Diets were isoenergitic and isonitrogeneous, providing 8% crude fat, in order to match the crude fat content associated with the highest inclusion rate of HO or HΩ tested (6%). The treatments were as follows: 1) Control diet with no supplemented HO or HΩ; 2) Control diet + 3% HO; 3) Control diet + 6% HO; 4) Control diet + 3% HΩ; 5) Control diet + 6% HΩ. 3% HΩ and 6% HΩ were equivalents for 3% HO and 6% HO, and their supplementation percentages were 10.45% and 20.90%,

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DIETARY HEMP OIL AND POULTRY PERFORMANCE

respectively. The birds were fed the experimental diets for a period of 21 days. Body weights and feed intake of all cages were recorded weekly. The FCR was calculated as grams of feed consumed per gram of weight gain. At the end of the experiment, 4 birds per sex per treatment were killed by cervical dislocation for collection of breast (white meat) and thigh (dark meat) which were then immediately stored at −20◦ C for fatty acid analysis. In order to reduce variation in the cutting procedure, one operator carried out all dissections.

Fatty Acid Analysis The fatty acid composition was determined using standard gas chromatographic techniques of the fatty acid methyl esters (AOAC, 1990, method 969.33), using C17:1 fatty acid (Nu-Chek Prep, Inc., Elysian, MN) as an internal standard. Total lipids were extracted from the test diets, egg yolks, breasts, and thighs by homogenization in chloroform/methanol (2:1, v/v) according to the methods of Folch et al. (1957). After centrifugation, the organic phase was collected and evaporated under a N2 stream. The all lipid extracts obtained were transesterified with methanolysis (1% (v/v) H2 SO4 in methanol) for 3 h at 70◦ C. After cooling, the resulting fatty acid methyl esters (FAMEs) were extracted with hexane and transferred into gas chromatography (GC) vials. All solvents contained 0.005% (v/v) butylated hydroxyanisole (BHA) as an antioxidant. FAMEs were then separated and quantified with a Varian450GC with CP-8400 autosampler, equipped with a flame ionization detector and a GC column (length 30 m, inner diameter 0.25 mm and film thickness 0.25 μm, DB-225MS) (Agilent Technologies, Mississauga, ON, Canada). Nitrogen was the carrier gas a column flow rate of 1 mL/min. The inlet split ratio was set at 10:1. The oven temperature programming was as follows: 60◦ C for 1.5 min, raised to 180◦ C at 20◦ C/min, 205◦ C at 6◦ C/min, 220◦ C at 2◦ C/min for 4 min, and 240◦ C at 10◦ C/min for 3 min. The injector and detector temperature were set at 260◦ C and 290◦ C, respectively. FAMEs were identified by comparison of retention times to known lipid standards (Nu-Chek Prep, Inc., Elysian, MN).

Statistical Analysis All data were analyzed as a completely randomized design with the individual hen (for the laying hen study) or the individual cage (for the broiler study) as the experimental unit. Data were log transformed before analysis in cases where there were unequal variances. Statistical analyses for fatty acid composition were based on ANOVA, using the PROC GLM procedure of SAS (SAS Institute Inc., Cary, NC), and a single-factor (treatment) model and two-factor (treatment and sex) model were used in the laying study and broiler study, respectively. For some specific fatty

Table 3. Egg weights, feed intake, final body weights, feed efficiency and hen-day egg production of hens fed diets containing HO or HΩ for 6 wk (21–27 wk of age).1

Item

Egg Daily Body Feed Hen-day egg weight feed weight conversion production (g) intake (g) (kg) ratio (g/g) (%)

Effect of treatment Control 57.5 4% HO 56.6 8% HO 57.4 4% HΩ2 56.9 8% HΩ2 54.5 SEM 0.87 Effect of time Wk1 54.5d Wk2 55.7c Wk3 56.5b,c Wk4 57.2a,b Wk5 57.9a Wk6 57.9a SEM 0.47 P value Treatment 0.149 Time < 0.001 Treatment × time 0.829

100.4 100.7 99.5 100.8 94.8 2.46

1.59 1.59 1.60 1.59 1.46 0.037

1.78 1.80 1.78 1.81 1.81 0.017

98.2 98.8 97.3 97.9 95.9 1.31

95.6b 96.1b 97.1b 101.9a 103.1a 101.7a 1.36

1.53c 1.55c 1.57b 1.57b 1.58b 1.59a 0.017

1.82a,b 1.76b 1.77b 1.84a 1.80a,b 1.80a,b 0.016

96.6 98.2 97.3 97.0 98.9 97.7 0.93

0.430 0.083 0.432 < 0.001 < 0.001 < 0.01 < 0.05 0.154 < 0.01

0.615 0.351 0.190

HO: hemp oil; HΩ: HempOmegaTM . a–d Values with different superscripts within each column are significantly different at P < 0.05. 1 Data are presented as least squares means and their SEM. 2 4% HΩ and 8% HΩ were equivalents for 4% HO and 8% HO, and their supplementation percentages were 14.88% and 29.76% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

acids, trends and comparisons in the response were evaluated by using Orthogonal Polynomial Contrasts. Statistical analyses of performance were based on repeated measures ANOVA, using the PROC MIXED procedure of SAS, with an adjustment for a random effect of hen or cage within treatment. In all analyses, least squares means were compared by Tukey’s procedure after ANOVA and differences were reported as significant when P < 0.05.

RESULTS Production Performance Performance of laying hens and broiler chickens is given in Tables 3 and 4, respectively. The introduction of HO or HΩ to the diets for laying hens and broiler chickens did not have any effect on overall performance of the birds. Performance parameters did however vary with age. With respect to laying hens, egg weights increased substantially from wk 1 to 2, steadily increased to wk 5 and remained constant thereafter (P < 0.001); daily feed intake significantly increased at wk 4 and then remained constant (P < 0.001); body weights increased from wk 2 to 3, remained similar till wk 5 and then increased at wk 6 (P < 0.001); FCR at wk 4 was significantly higher than wk 2 or wk 3 (P < 0.01). Interaction effects between treatment and time were significant

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JING ET AL. Table 4. Growth, feed intake, and feed efficiency of broiler chickens fed diets containing HO or HΩ for 21 d (day 0 to 3 wk of age).1 Item Effect of treatment Control 3% HO 6% HO 3% HΩ2 6% HΩ2 SEM Effect of sex

Daily weight Daily feed Feed conversion gain (g) intake (g) ratio (g/g) 42.2 41.8 41.5 40.6 42.8 0.71

56.2 54.9 54.0 53.9 56.2 1.05

1.29 1.28 1.27 1.28 1.27 0.015

F M SEM Effect of time

40.5b 43.1a 0.45

53.3b 56.8a 0.66

1.28 1.27 0.009

1-7 days 8-14 days 15-21 days 1-21 days SEM P value Treatment Sex Time Treatment × sex Treatment × time Sex × time Treatment × sex × time

17.9d 43.6b 63.9a 41.8c 0.46

20.1c 54.7b 90.3a 55.0b 0.72

1.12d 1.26c 1.41a 1.32b 0.012

0.319 < 0.01 < 0.001 0.161 0.343 < 0.01 0.814

0.373 < 0.01 < 0.001 0.231 0.337 < 0.001 0.412

for daily feed intake and FCR (P < 0.05). For broiler chickens, daily weight gain, daily feed intake, and FCR significantly increased (P < 0.001) as expected over the three 7-d periods. With respect to sex effect, male broilers had higher daily weight gain and feed intake than females (P < 0.01), and no significant differences were found for FCR between the two sexes. Interaction between sex and time was found to be significant (P < 0.05) in the broilers. Collectively, the observed interaction, age or sex effects on the aforementioned performance parameters could be related to physiological and developmental conditions of the host.

Fatty Acid Profiles

0.840 0.455 < 0.001 0.890 0.824 < 0.05 0.427

HO: hemp oil; HΩ: HempOmegaTM . a–d Values with different superscripts within each column are significantly different at P < 0.05. 1 Data are presented as least squares means and their SEM. 2 3% HΩ and 6% HΩ were equivalents for 3% HO and 6% HO, and their supplementation percentages were 10.45% and 20.90% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

From a numerical perspective, ALA content of the diets for laying hens and broilers dramatically increased with increasing levels of HO or HΩ, and LA was generally unchanged or changed only slightly (Tables 1 and 2). The fatty acid composition of the egg yolks and chicken muscle is shown in Tables 5, 6 and 7. For the egg yolks, HO or HΩ inclusion in the diet significantly increased the concentrations of PUFAs, particularly n-3 type, and decreased monounsaturated fatty acids (MUFAs), mainly oleic acid (C18:1) (P < 0.01). Compared to yolks of layers fed the control diet, the inclusion of 4% and 8% HO or HΩ yielded a 3.2- to 6.0-fold increase in total n-3 PUFAs, 4.7- to11.5-fold ALA (18:3n-3), 17- to 26-fold EPA (20:5n-3), 2.1- to 2.7-fold docosapentaenoic acid (DPA; 22:5n-3), 2.3- to 2.7-fold DHA (22:6n-3), and 2.4- to 2.7-fold LC n-3 PUFAs (P < 0.001); inclusion of 8% HO or HΩ led to an approximately 1.5-fold increase in GLA (18:3n-6)

Table 5. Fatty acid composition of the egg produced by hens fed diets containing HO or HΩ for 6 wk (21–27 wk of age).1 Treatment Fatty acid (mg/yolk)

Control

4% HO

8% HO

4% HΩ2

8% HΩ2

SEM

P value

C14:0 C16:0 C16:1 C18:0 C18:1 C18:2n-6 C18:3n-6 C18:3n-3 C20:4n-6 C20:5n-3 C22:5n-3 C22:6n-3 Total SFAs Total MUFAs Total n-6 Total n-3 Total LC n-3

10.1 859 36.9 355 1,105a 974 7.3b 13.7c 88.5a 0.1b 2.2b 20.3b 1,224 1,141a 1,070 36.4c 22.6b

8.9 813 32.5 405 973a 895 7.4b 64.3b 66.8b 1.7a 4.7a 47.3a 1,227 1,005a 969 118.0b 53.8a

10.6 860 37.4 424 940a,b 1,081 10.4a 125.6a,b 78.5a,b 2.5a 5.4a 49.7a 1,295 977a,b 1,170 183.2a,b 57.6a

9.0 795 31.6 358 940a,b 1,102 9.8a,b 99.3a,b 74.6a,b 1.9a 5.6a 54.5a 1,162 972a,b 1,186 161.3a,b 62.0a

8.3 674 27.7 325 687b 1,067 12.6a 157.4a 68.2b 2.6a 5.9a 50.7a 1,008 715b 1,148 216.6a 59.2a

0.72 51.0 2.49 27.5 67.0 68.2 0.71 12.28 5.06 0.28 0.56 3.94 77.2 68.9 73.3 16.09 4.67

0.162 0.098 0.055 0.096 < 0.01 0.196 < 0.001 < 0.001 < 0.05 < 0.001 < 0.001 < 0.001 0.126 < 0.01 0.231 < 0.001 < 0.001

HO: hemp oil; HΩ: HempOmegaTM ; MUFAs: monounsaturated fatty acids; SFAs: saturated fatty acids. Total LC n-3 refers to the total of EPA (C20:5n-3), DPA (C22:5n-3), and DHA (C22:6n-3), and the same thing applies to the other tables. a-c Values with different superscripts within each row are significantly different at P < 0.05. 1 Data are presented as least squares means and their SEM. 2 4% HΩ and 8% HΩ were equivalents for 4% HO and 8% HO, and their supplementation percentages were 14.88% and 29.76% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

7

DIETARY HEMP OIL AND POULTRY PERFORMANCE

Table 6. Fatty acid composition of the thigh from broiler chickens fed diets containing HO or HΩ for 21 d (day 0 to 3 wk of age).1 Effect of treatment

Effect of sex

P value

Fatty acid (mg/100 g muscle) Control

3% HO

6% HO

3% HΩ2

6% HΩ2

SEM

F

M

SEM

Treatment

Sex

Treatment × sex

C14:0 C16:0 C16:1 C18:0 C18:1 C18:2n-6 C18:3n-6 C18:3n-3 C20:4n-6 C20:5n-3 C22:5n-3 C22:6n-3 Total SFAs Total MUFAs Total n-6 Total n-3 Total LC n-3

9.4 185 19.6 95 185b 349 7.9a,b 41.5a,b 52.1 4.9b 15.0b 10.0b 290 205b 409 71.4a,b 29.9b

9.5 237 30.7 119 258a,b 543 20.6a 106.4a 57.9 7.4a 20.3a,b 14.9a,b 366 289a,b 621 148.9a 42.6a

9.1 205 19.6 111 224b 460 9.7a,b 49.7a,b 66.1 4.5b 17.3a,b 14.1a,b 325 243b 535 85.6a 35.9a,b

8.2 197 17.1 118 179b 563 20.8a 106.2a 61.3 6.4a,b 20.7a 17.5a 323 197b 645 150.7a 44.5a,b

0.75 33.8 7.81 11.3 62.4 82.5 4.35 21.78 3.38 0.57 1.23 1.13 44.2 69.9 88.0 23.35 2.67

9.7 250 31.1 117 309 543 14.1 73.0 57.6 5.1 15.6 12.2 377 340 615 106 33.0

8.7 200 21.4 105 221 437 11.4 58.9 59.9 4.8 16.2 12.4 313 242 508 92 33.4

0.48 21.4 4.94 7.2 39.5 52.2 2.75 13.77 2.14 0.36 0.78 0.72 27.9 44.2 55.6 14.8 1.69

0.589 0.155 0.061 0.592 < 0.05 0.364 < 0.01 < 0.01 0.079 < 0.001 < 0.001 < 0.001 0.301 < 0.05 0.357 < 0.001 < 0.001

0.170 0.124 0.244 0.232 0.222 0.163 0.497 0.448 0.470 0.487 0.638 0.836 0.118 0.226 0.188 0.552 0.875

0.312 0.586 0.703 0.758 0.766 0.441 0.427 0.342 < 0.05 0.772 0.485 0.201 0.529 0.766 0.455 0.323 0.332

9.9 300 44.2 112 477a 537 4.6b 26.0b 56.5 1.7c 6.3c 5.1c 422 521a 598 39.0b 13.1c

HO: hemp oil; HΩ: HempOmegaTM ; SFAs: MUFAs: monounsaturated fatty acids; SFAs: saturated fatty acids. a-c Values with different superscripts within each row are significantly different at P < 0.05. 1 Data are presented as least squares means and their SEM. 2 3% HΩ and 6% HΩ were equivalents for 3% HO and 6% HO, and their supplementation percentages were 10.45% and 20.90% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

Table 7. Fatty acid composition of the breast from broiler chickens fed diets containing HO or HΩ for 21 d (day 0 to 3 wk of age).1 Fatty acid

Effect of treatment

Effect of sex 2

(mg/100 g muscle)

Control

3% HO

6% HO

3% HΩ

C14:0 C16:0 C16:1 C18:0 C18:1 C18:2n-6 C18:3n-6 C18:3n-3 C20:4n-6 C20:5n-3 C22:5n-3 C22:6n-3 Total SFAs Total MUFAs Total n-6 Total n-3 Total LC n-3

5.7 140 16.8 56.0 179 224 3.4b 15.9b 38.5 2.2c 5.7c 4.5b 201 196 265 28.4c 12.5c

7.6 172 20.1 68.4 186 289 7.6a 39.1a 40.6 5.5b 13.2b 9.3a 248 206 337 67.2b,c 28.1b

7.4 199 28.3 77.6 188 396 17.3a 86.6a 41.6 7.2a 17.6a 12.6a 284 216 455 124.0a 37.4a

6.5 164 14.5 70.5 173 372 11.0a 51.8a 44.9 4.8b 14.7a,b 12.2a 241 187 428 83.6a,b 31.8a,b

P value

2

SEM

F

M

SEM

Treatment

Sex

Treatment × sex

7.0 156 14.0 71.9 148 334 10.5a 50.5a 44.2 5.3b 15.8a,b 11.4a 235 162 389 83.0a,b 32.5a,b

0.51 19.9 4.87 5.60 28.3 46.5 2.40 11.69 2.29 0.39 0.95 0.82 25.5 32.4 50.0 13.13 2.05

6.78 152 14.8 66.2 154 296 8.8 42.8 41.7 4.9 13.7 10.4 225 169 346 71.8 29.0

6.95 180 22.7 71.6 195 350 11.0 54.8 42.2 5.1 13.0 9.6 258 218 403 82.7 27.8

0.32 12.6 3.08 3.54 17.9 29.4 1.52 7.39 1.45 0.24 0.60 0.52 16.1 20.5 31.6 8.31 1.30

0.092 0.331 0.407 0.079 0.864 0.094 < 0.001 < 0.001 0.281 < 0.001 < 0.001 < 0.001 0.279 0.805 0.084 < 0.001 < 0.001

0.709 0.135 0.070 0.277 0.113 0.202 0.267 0.135 0.821 0.458 0.410 0.315 0.160 0.099 0.212 0.362 0.519

0.116 0.291 0.314 0.284 0.604 0.378 0.296 0.166 0.100 0.173 0.250 0.362 0.284 0.553 0.380 0.419 0.311

6% HΩ

HO: hemp oil; HΩ: HempOmegaTM ; MUFAs: monounsaturated fatty acids; SFAs: saturated fatty acids. a-c Values with different superscripts within each row are significantly different at P < 0.05. 1 Data are presented as least squares means and their SEM. 2 3% HΩ and 6% HΩ were equivalents for 3% HO and 6% HO, and their supplementation percentages were 10.45% and 20.90% respectively, given the analytic result that HΩ contained 26.9% hemp oil.

(P < 0.001), and a decrease in total MUFAs or oleic acid (P < 0.01) (Table 5). Furthermore, analysis of Orthogonal Polynomials and Contrasts showed that yolk GLA and EPA were linearly elevated (P < 0.01), and other individual n-3 fatty acids or total n-3 increased in a quadratic manner as dietary inclusion level of HO or HΩ increased (P < 0.05); 4% HΩ had a higher deposition efficiency of GLA in comparison to 4% HO (P < 0.05) (Table 8). Similarly, increases in n-3 fatty acids and GLA were also observed in thigh meat (dark meat) from broiler chickens. Compared to thigh meat of broilers fed the control diet, the inclusion of 3% and 6% HO or HΩ yielded a 1.8- to 3.9-fold increase in total n-3 PU-

FAs, 1.6- to 4.1-fold ALA, 2.6- to 4.4-fold EPA, 2.4- to 3.3-fold DPA, 2.0- to 3.4-fold DHA, and 2.3- to 3.4- fold total LC n-3 (P < 0.01); GLA was increased approximately 4.5-fold by the inclusion of 6% HO or HΩ (P < 0.01); total MUFAs or oleic acid were reduced in 3% HO, 3% and 6% HΩ treatments (P < 0.05) (Table 6). GLA and individual or total n-3 fatty acids increased linearly with increasing inclusion level of HO in diets (P < 0.001). A linear increase of those fatty acids was also found in response to increases in HΩ inclusion rate (P < 0.001), except for DPA and LC n-3 which were increased quadratically (P < 0.05). DHA was more deposited in thigh meat of broilers fed 3% HΩ compared

8

< 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.01 < 0.001

0.753 0.477 0.103 0.188 0.448 0.579 0.222 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001

0.585 0.601 0.619 0.210 < 0.05 0.551 0.133 0.998 0.872 0.526 < 0.05 0.054 0.707 < 0.05 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001

0.630 0.556 0.620 0.266 0.964 0.903 0.521 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.05 0.055 0.635 0.373 0.322 0.090 0.334

0.957 < 0.001 0.083 < 0.01 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001

0.116 < 0.01 0.184 < 0.05 < 0.001 < 0.01 < 0.001 < 0.01 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001

GLA ALA EPA DPA DHA n-3 LC n-3

HO: hemp oil; HΩ: HempOmegaTM . 1 Some specific polyunsaturated fatty acids that were significantly affected by treatment shown in Tables 5, 6, and 7 were considered for further analysis using Orthogonal Polynomials and Contrasts, and only P values were reported in the table. 2 The inclusion level of 4% hemp oil provided by HO or HΩ was analyzed for the egg yolk, and the inclusion level of 3% hemp oil provide by HO or HΩ was analyzed for the thigh and breast meat.

0.124 0.227 0.246 0.274 < 0.05 0.383 0.211 < 0.01 < 0.01 < 0.05 < 0.01 < 0.001 0.093 < 0.001

Quadra HΩ Linear Quadra Linear HO2 vs. HΩ Quadra Linear Quadra Linear FA

Egg yolk

HΩ HO

Table 8. Analysis of Orthogonal Polynomials and Contrasts.1

Linear

HO

Quadra

HΩ

Thigh meat

HO2 vs. HΩ

Linear

HO

Quadra

Breast meat

HO2 VS. HΩ

JING ET AL.

to the same level of HO (P < 0.05) (Table 8). Increased n-3 fatty acids and GLA were also observed in the breast meat (white meat) of broilers fed diets containing HO or HΩ, however, the total MUFAs content was not significantly affected by dietary treatments. Compared with control, the inclusion of HO or HΩ (3% & 6%) yielded an increase of 2.4- to 4.4-fold in total n-3 PUFAs, 2.5- to 5.4-fold ALA, 2.2- to 3.3-fold EPA, 2.3- to 3.1-fold DPA, 2.1- to 2.8-fold DHA, and 2.2- to 3.0-fold LC n-3 (P < 0.001); GLA was increased 2.2 to 5.1-fold by the inclusion of either level of HO or HΩ (P < 0.001) (Table 7). Relative to thigh meat, breast meat GLA and n-3 fatty acids linearly increased with increasing dietary level of HO (P < 0.001), but responded in a quadratic manner to the increased dietary HΩ (P < 0.05) except for total n-3 that had a positive linear relationship with the inclusion level of HΩ in diets (P < 0.01); DHA content was also higher in breast of broilers fed on 3% HΩ than those fed on 3% HO (P < 0.05) (Table 8). On the other hand, the content of total n-6 PUFAs, LA, arachidonic acid (ARA), or total saturated fatty acids (SFAs) of the egg yolk and chicken meat was generally unchanged between treatments. Overall, the effects of sex or interaction between treatment and sex were nonsignificant for the fatty acid composition of the thigh and breast meat from broilers.

DISCUSSION Consumer demand for food products of superior health quality has driven interest in enhancing the n3 fatty acid deposition of poultry meat and eggs. To date, the enrichment the meat or eggs with n-3 fatty acids is achieved mainly by using flaxseed or flaxseed oil and marine oils in the bird diets (Moghadasian, 2008; Palmquist, 2009). Alternatively, microalgae products (e.g., DHA Gold) have been increasingly used in animal feeds for enriching DHA in the meat and eggs (Gonz´ alez-Esquerra and Leeson, 2001; Ribeiro et al., 2014). This can be considered a significant accomplishment for fulfilling current recommendations of increasing n-3 fatty acid intakes, particularly in most western countries where the recommended daily intake of these compounds is rarely met (Kris-Etherton et al., 2000, 2003). Another promising source for n-3 is hemp seed and its by-products such as HO, but their use as poultry feed ingredients has not been approved by certain government regulatory agencies, including those in Canada, due to a lack of scientific evidence to support the safety and efficacy claims. To fill in the gap, the present study investigated different levels of HO and HΩ in diets for laying hens and broiler chickens and their effect on fatty acid composition of egg yolks and meat, and production performance of birds. In the current study, production performance (feed intake, egg weight, egg production, feed conversion ratio, body weight, or weight gain) of laying hens and broiler chickens was not affected by dietary supplemen-

DIETARY HEMP OIL AND POULTRY PERFORMANCE

tation with HO or HΩ (up to 8% for the laying hen diet and 6% for the broiler diet), when compared with birds fed the control diet. These results are consistent with our previous studies on the effects of HO in layers (Gakhar et al., 2012; Neijat et al., 2014). The interaction between treatment and time was found to be significant for feed intake and FCR in laying hens but not in broilers, indicating the effect could be transient or related to developmental physiology of the host, and likely not specifically related to the dietary treatment. Overall, the data from the current study support a potential use of HO and HΩ as ingredients in the feed for layers and broilers. Data on the safety of hemp oil for poultry was provided by some members of our group. Neijat et al. (2014) reported that feeding up to 9% HO did not affect plasma chemistry of laying hens. It has been shown that THC was undetectable in the tissues (breast, thigh, liver and kidney) when broiler chickens were fed up to 9% HO for 35 d (J. D. House, unpublished data). The analysis of fatty acid profile showed HO and HΩ significantly increased the content of total n-3 PUFAs or the individual n-3 PUFAs, ALA, EPA, DPA, or DHA of egg yolk, thigh (dark meat) and breast (white meat) to a different extent. Similarly, it was reported in the previous work of our research team that use of HO in hen diets led to increased n-3 fatty acid content of yolks (Goldberg et al., 2012). The current data also showed that inclusion of 3% HΩ in the broiler diet yield higher DHA enrichment values relative to the same level of HO. Moreover, the enrichment trend for HO and HΩ was somewhat different, as reflected by the results that the individual or total n-3 fatty acids in both thigh and breast meat linearly increased with the increasing level of HO in diets, but some of those fatty acids responded in a quadratic manner to increased dietary levels of HΩ. Nonetheless, inclusion of HO or HΩ enhanced egg yolk n-3 fatty acids in an identical manner. The present study also showed that the content of total MUFAs, mainly oleic acid (C18:1) of egg yolk and thigh meat, was reduced for birds receiving HO or HΩ. The reduction of MUFAs might be due to the fact that n-3 PUFAs effectively inhibit the activity of Δ-9 desaturase, an enzyme which is necessary in the formation of MUFAs from their precursors. The Δ-9 desaturase is essential for conversion of palmitic (C16:0) to palmitoleic acid (C16:1) and stearic (C18:0) to oleic acid (C18:1) (Palmquist, 2009). If this speculation is correct, the content of stearic acid would be expected to increase in accordance with the oleic acid decrease. However, the level of stearic acid was not significantly different between dietary treatments in the current study. Instead, the confounding diets could better explain the reduction in oleic acid. Since the hemp-supplemented diets contained much less oleic acid as compared to the controls, and this would be most likely why the eggs and meat contained less total MUFAs with supplementation of HO or HΩ. Consistent with the previous report

9

by Goldberg et al. (2012), the proportion of LA or total n-6 PUFAs was not significantly affected by dietary treatment in the current study. On the other hand, it was noticed that the level of GLA in either poultry meat or eggs was increased by the inclusion of HO or HΩ, and further analysis showed that HΩ led to higher GLA contents in egg yolks than HO at the 4% inclusion level. Park et al. (2014) recently suggested that GLA-reinforced functional eggs can be produced by adding HO to the feed for laying hens (Park et al., 2014). The improvement of GLA by hemp products adds a unique feature in the enrichment of foods with n-3 fatty acids, in comparison with those by flax products, and has important implications for human health, given the desirable biological functions of GLA as mentioned earlier. The extent of n-3 PUFA enrichments may vary with tissue type or animal species. The current study showed that the enrichment efficiency for total n-3 PUFAs, ALA, or EPA via the inclusion of hemp products appeared to be higher in egg yolks than in chicken meat compared to their respective controls, particularly, EPA level was significantly increased 17 to 26-fold in egg yolks relative to approximately 2.5 to 4-fold in the two types of meats. Further it was noted that lower levels of HO inclusion had no impact on total n-3 PUFAs of the thigh and breast but significantly increased the content of the egg yolk. Additionally, our data showed that unlike egg yolk fatty acid profile, DPA was higher than DHA in breast and thigh meat. It has been commented that increasing dietary flaxseed oil did not increase DHA in muscle in the same manner that it increased in the yolk of laying hens (Palmquist, 2009). Kouba and Mourot (2011) reported that DPA levels were higher than DHA in the pectoralis muscle of turkeys fed flaxseed oil. Given that the conversion of DPA to DHA involves in the sequential reactions of elongation, desaturation, and beta-oxidation (Sprecher, 2000), it could be speculated that the expression and activity of enzymes required in the reactions, including fatty acid desaturase 2 (FADS2) and fatty acid elongase 5 (ELOVL5), may be low in the muscle tissue of chickens and, therefore, inhibits the metabolism of DPA to DHA. However, further mechanistic studies are required to elucidate the biological rationale for this limited conversion. In addition to questions of efficacy, the introduction of novel feed ingredients into poultry diets must also be weighed against any potential negative impacts on the sensory characteristics of the resultant meat and eggs. This becomes a more important concern when using ingredients rich in n-3 fatty acids due to increased liability to oxidation. It has been reported that inclusion of higher levels of fish oil or flaxseed oil compromises the sensory quality of the poultry meat and eggs due to the presence of fishy smell/taste (Van Elswyk et al., 1995; Grune et al., 2001; Moghadasian, 2008). Although sensory evaluation was not conducted in the current study,

10

JING ET AL.

our previous work did show that use of up to 20% hemp seed and 10% HO in hen diets increased color intensity of egg yolks but did not have adverse effects on the sensory profiles of the cooked eggs (Goldberg et al., 2012). Another study showed that consumers’ acceptability towards breast and thigh meat from broiler chickens fed a diet containing 30% hemp seed or 9% HO was similar to those from chickens fed a control diet (J. D. House, unpublished data). These results indicate that use of hemp products would not compromise the sensory quality of poultry products. However, this still requires confirmation in future studies. In summary, the present study showed that inclusion of hemp oil provided by HO or HΩ in the diets for laying hens (up to 8%) and broiler chickens (up to 6%) did not have an adverse effect on the performance of birds. Birds fed HO or HΩ exhibited increased incorporation of n-3 PUFAs and GLA into egg yolks and meat to a different extent. Overall, the current data provide evidence in support of efficacy claims for the use of hemp oil products in the poultry rations, and this would be a potentially effective way to modify the fatty acid profile of eggs or meat in a way that is desired from the standpoint of human health.

ACKNOWLEDGEMENTS This study was financially supported by the Canadian Hemp Trade Alliance (Winnipeg, Manitoba, Canada), Canadian Agricultural Adaptation Program (Ottawa, Ontario, Canada), Province of Manitoba Science and Technology International Collaboration Fund (Winnipeg, Manitoba, Canada), Natural Sciences and Engineering Research Council of Canada (NSERC) Engage program, and Boreal Technologies (Vancouver, British Columbia, Canada). The in-kind contribution of hemp oil by Hemp Oil Canada (St. Agathe, Manitoba, Canada) and Boreal Technologies is kindly acknowledged. The authors would also like to thank Dr. G. Crow (Department of Animal Science, University of Manitoba) for statistical assistance, J. Levandoski and A. Chartier (Poultry Research Unit, University of Manitoba, Winnipeg, Manitoba) with animal care and J. Neufeld (Department of Animal Science, University of Manitoba) for laboratory analysis.

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