Influence of Dietary L-Carnitine on Productive Performance, Internal Organs and Carcass Characters of Two Duck Breeds Reared for Foie Gras Production

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1 Alexandria Journal of Veterinary Sciences. 205, 44: ISSN , DOI: /ajvs Mona E.M. Younis /Alexandria Journal of Veterinary Sciences 205, 44: Influence of Dietary L-Carnitine on Productive Performance, Internal Organs and Carcass Characters of Two Duck s Reared for Foie Gras Production Mona, E. M. Younis Department of Animal Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, Damanhour University, Egypt. ABSTRACT: Key Words: L-carnitine ducks performance internal organs carcass A total of 20 male ducks and 20 male ducks reared for foie gras production were used to study the effect of dietary L-carnitine supplementation on productive performance, internal organs and carcass characters. Ducks of each genotype were allotted into two groups (n=60), the first group received dietary L-carnitine at level of 500mg/kg ration and the other keep as control. L-carnitine supplementation increased body weights at 2 and 4 weeks significantly than control groups also weight gain and relative growth rate from hatch to 2 weeks were significantly increased in L-carnitine groups. From the 6 week of age the effect of L-carnitine on body weight and weight gain were not significant. Dietary L-carnitine increased significantly heart weight and heart percentage of life weight in ducks and pancreas percentage of life weight in ducks compared to their control groups. However, all other body organs, carcass characters and carcass parts chemical composition did not differ significantly. ducks recorded significantly higher life weight, carcass weight, dressing %, total fillet weight, shoulder weight and thigh weight and percentage of life weight than ducks. The benefit from dietary L-carnitine on productive performance traits can be obtained within the first 4 weeks of life also marketing of Mule ducks should be at 8 weeks old age, however ducks marketing could be delayed till 0 weeks old age. Corresponding Author: Mona, E. M. Younis: dr.monapp@yahoo.com. INTRODUCTION The amino acid derivative L-carnitine (β hydroxy- -trimethylaminobutyrate) has gained interest in recent years as a potential feed additive for improving domestic animal production because of its metabolic functions. Although, little L-carnitine has been reported to be found in cereal grains and their by-products (Baumgartner and Blum, 993), which usually constitute the major portion of poultry diets, nevertheless, endogenous biosynthesis together with dietary L-carnitine supply are sufficient to cover normal requirements in poultry breeding since carnitine can be biosynthesized endogenously from methionine and lysine, these two amino acids are usually more important limiting amino acids in poultry nutrition. However, supplementation with L-carnitine or precursors and cofactors may be required when metabolic rate and energy demands are increased, where (Rabie and Szilagyi, 998; Celik and Ozturkcan, 2003) attributed the increase in growth during early age in response to supplemental dietary L-carnitine to higher requirement of broiler chickens for L-carnitine during rapid growth period. Only three waterfowl genotypes are currently used for force-feeding in France: the grey Landaise goose strain (Anser anser), the duck (Cairina moschata) and the Mule duck, a hybrid resulting from an inter-cross between a drake and a female common duck (Anus plutyrhynchos) (Gukmene and Guy, 2004). However, foie gras production from ducks were accounting nearly 98 % of the domestic foie gras production however, geese making up only about 2 % (French industry figures, 2007). Mamayev et al., (980) & Veremeenko & Kutnyuk, (995) recorded highly correlation coefficient between life weight before foie gras production, final weight after production and foie gras weight. The present study was performed to estimate the effect of L-carnitine supplementation on productive performance traits, body organs weight, carcass parts weight and chemical composition of male Mule and ducks used for foie gras production. 59

2 2. MATERIALS AND METHODS 2..Ducks and experimental design One hundred and twenty male ducks (Cairina moschata) and one hundred twenty male ducks (sterile and artificial hybrid resulting from an inter-cross between a drake and a female common duck (Anus plutyrhynchos) were obtained from El Francea Company for duck production at the same day. After arrival of duck chicks to the Duck Research Unite, Department of Animal Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, Damanhour University, where experiment was carried out, they were wing banded then ducks of each genotype were divided into two groups (n=60), the first group supplied with dietary L-carnitine (β hydroxy- -trimethylaminobutyrate at level of 500mg/kg ration Kita et al., (2002) and the second did not receive L-carnitine (control), this division resulted into four groups these are:. ducks received L-carnitine 2. ducks did not receive L-carnitine (control) 3. ducks received L-carnitine 4. ducks did not receive L-carnitine (control). 2.2.Management during brooding period Brooding period of ducks extended through the first 3 weeks of age. During this period duck chicks were housed collectively, however, each group was bred in separated pen. Birds were floor brooded under gas heater, ambient temperature was 30 o C at one day old age descended to 27 o C by the end of the first week, then lowered to 23 o C by the end of second week while by the end of the third week temperature was 9oC. Ducklings received lighting for 24 hours in the first two days then, 23 hours on and one hour off daily. Where they had free access to a starting diet containing 2900 kcal, 34 g lipid and 200 g protein per kg from 0 to 2 week of age according to NRC (994), water should be available all time Management during growing period Growing period extended from 3rd till 2th weeks of age where ducklings had free access to outdoor yard divided by partitions into four groups to include the four groups of the treatment. Ducks had free access to a growing diet from 2 to 6 weeks containing 2750 k Cal, 34 g lipid and 82 g protein per kg. From 6 to week according to NRC (994), the daily intake 60 of the growing diet was reduced to 220 g/duck/day (quantitative feed restriction), then from -2 weeks feed intake increased to its maximum level 320g/duck/day Hermier et al. (2003). 2.4.Estimated productive performance traits Body weight: Body weight was recorded biweekly to the nearest gram using digital balance. Weight gain = W2-W Where: W=is the weight at any week and W2=is the weight at the next week. Relative growth rate: Relative growth rate was calculated according to Brody (945) 2.5.Estimation of carcass traits Ducks were deprived of feed for 2 hours before slaughtering, but with continue to supply with water, then slaughtering of ducks applied manually followed by scalding and plucking, after the bleeding was completed, ducks were manually plucked after scalded the carcass by immersing it in water at C. Evisceration was applied by extracting all internal organs (liver, intestine, heart, gizzard, proventriculus and spleen) and abdominal fat (included gizzard fat). Weight of internal organs and carcass after evisceration, removal of head, neck and legs were recorded to the nearest gram. Partitioning: from each treatment three carcasses were dissected into thigh, shoulder and the total left fillet then weighed. The fillet was dissected pectorals major muscle and associated subcutaneous adipose tissue (skin included) according to Hermier et al. (2003). 2.6.Breast muscle and liver chemical Analysis Organ sampling: from each treatment three 3 ducks were utilized for organs chemical analysis where 70 g from ventromedial portion of the main lobe (right lobe) of liver and 70 g from left fillet muscles were collected and frozen at -20 oc for subsequent analyses and enzyme activity determination according to Hermier et al. (2003). 2.7.Chemical analysis:.determination of moisture content according to (AOAC, 2000):

3 2.Determination of ether extract content according to (AOAC, 2000): 3.Determination of crude protein content: The protein content was determined by Kjeldahl method according to Randhir and Pradhan (98). 2.8.Statistical analysis The productive and carcass traits data (absolute and relative life weight at 2 weeks old) were analyzed three way analysis of variance by SAS (2002), Proc GLM 4. RESULTS 3..Productive performance traits 3..Body weight Addition of L-carnitine to diet increased body weights at 2 and 4 weeks significantly than control groups ( ± 5.56 g and ± g vs ± 5.78 g and 08.4 ± 4.99 g respectively P<0.0), however after this age effect of L-carnitine on improving body weights was non-significant. At 2 weeks old age body weight of ducks L-carnitine group was significantly higher ( ± 8.44 g) than Mule duck L-carnitine group ( ± 5.89 g), moreover the two weights were higher than control groups ( ± 7.07 g and ± 6.47 g for and Mule ducks respectively P<0.0). Mule ducks L-carnitine group had higher 4 weeks body weights average ( ± 7.46 g) than Mule duck control, ducks L-carnitine and control groups (5.96 ± 8.20 g, ± 2.99 g and ± 8.83 g resp. P<0.0). From the 6 week of age the effect of L-carnitine on body weight was decreased and hesitated, however, it increased body weights of Mule ducks than its control group, body weights of control group were higher than of L-carnitine group in ducks (the increment was non-significant) (Table ). Mule ducks recorded significantly higher body weight at 4, 6 and 8 weeks of age than ducks, on contrary at 2, 0 and 2 weeks of age ducks body weights were significantly higher than Mule (Table ) Weight gain (WG) 6 L-carnitine treatments recorded significantly higher weight gain from hatch to 2 weeks compared to control group ( ± 4.98 g vs ± 5.58 g P<0.0), however its effect on further weight gains was not significant. ducks had significantly higher weight gain from hatch to 2 weeks, from 6 to 8 weeks, from 8 to 0 weeks and from 0 to 2 weeks (254.0 ± 4.98 g, 52. ± g, ± 3.63 g and ± g) than Mule ducks (99.2 ± 4.28 g, ± 4.28 g, 450. ± 7.34 g and ± 8.82 g resp. P<0.0), however weight gain from 2 to 4 weeks and from 4 to 6 weeks were higher in Mule ducks than ducks ( ± 0.62 g and ± 0.48 g vs ± 5.07 g and ± g P<0.0). ducks control group had significantly higher weight gain from hatch till 2 week of age than Mule ducks control groups, Moreover, weight gain from 2-4 week of the two Mule groups were significantly higher than their counterpart of ducks (Table 2). Although effect of L-carnitine on further weight gains was not significant, Mule ducks L- carnitine group recorded higher weight gain from 8-0 weeks than control group (Table 2) Relative growth rate (RGR) L-carnitine treatments showed significantly higher relative growth rate between hatch and 2 weeks of age (39.45 ± 0.76%) than control treatments (33.4 ±.33% P<0.0), while the adverse was occurred from 2 to 4 weeks, 4 to 6 weeks and 6 to 8 weeks of age where the control groups of ducks exhibited significantly higher relative growth rate (20.73 ±.7 %, ± 0.87% and ±.23%) than L-carnitine groups (7.7 ±.87%, ± 0.88% and ±.7% respectively P<0.0). Supplemental L-carnitine effect on further relative growth rates was not significant. The data presented in (Table 3) showed that relative growth rate between hatch and 2 weeks, 6 and 8 weeks and 8 and 0 weeks were significantly higher in ducks (43.73 ± 0.33%, ±.47% and ± 0.94% respectively) than in Mule ducks (29 ±.2%, ± 0.49% and 2.20 ± 0.47% respectively P<0.0), however, the opposite was true for relative growth rate from 2-4 weeks and 4-6 week, where the ducks had significantly higher values (3.2 ± 0.73% and ± 0.67%) than ducks (06.60 ±

4 .62% and ±.05% respectively P<0.0). Total relative growth rate between hatch and 2 weeks of age was significantly higher in ducks than in Mule ducks (95.72 ± 0.09%vs ± 0.0% P<0.0). 3.2.Carcass characters Body organs Addition of L-carnitine to duck ration at level of 500 mg/kg ration did not effect on body organs either as absolute weight or as a percentage of life weight where there is no significant difference between these values in control and treated groups (table 4 and 5) except for heart weight and heart percentage of life weight were these values for ducks under L- carnitine treatment were significantly higher than its control groups (43.5±3.52 g and 0.82±0.04% vs ±3.07 g and 0.64±0.06 % respectively), moreover, pancreas percentage of life weight was significantly higher in mule ducks L-carnitine group than its control group (0.25±0.0 % vs. 0.20±0.0%). ducks recorded significantly higher carcass weight, dressing percentage, abdominal fat weight and percentage than ducks ( ±38.65 g, 69.7±0.92 %, 57.00±.50 g and.6±0.24% vs ±5.28 g, 63.92±.02%, 4.83±3.30 g and 0.36±0.08% respectively). However, ducks had significantly higher gizzard and pancreas percentages of life weight (.82±0.5 % and 0.22±0.0 %vs..46±0.06 % and 0.6±0.0 % respectively) Carcass cuts Dietary L-carnitine did not significantly effect on carcass parts either as absolute weight or as percentages of life weight (Table 6). However, ducks recorded significantly higher thigh weight and percentage (45±0.49 g and 8.6±0.22%), shoulder weight (272.00±0.07g) and total fillet weight (58.00±39.86g) compared to ducks (303.33±8.27g, 7.20±0.7%, 90.83±4.55g and 35.67±2.22g respectively P<0.05) Breast muscle and liver chemical analysis Chemical analysis of breast muscle and liver summarized in Table (7)showed that supplementation of L-carnitine to ducks at level of 500 mg/ kg ration did not significantly affect chemical composition of liver or breast muscles also the two duck breeds had similar breast muscle and liver chemical composition DISCUSSION Ducks L-carnitine supplementation at level of 500 mg / kg ration positively affected body weight, weight gain and relative growth rate during the first 4 weeks of age, this situation might be related to the positive effect of L- carnitine on lipid and energy metabolism. Gropp et al., (994) reported that dietary L-carnitine supplementation could improve fatty acid and energy utilization and, therefore, live weight gain and feed conversion efficiency may be improved in poultry. However after 4 weeks of age effect of L- carnitine on growth performance traits was not significant, this could be resulting from decrease requirement to it with increase of age. Similar results were concluded by Rabie and Szilagyi, (998); Sayed et al., 200; Elik et al., (2003) where dietary supplemental L-carnitine or L- carnitine ± niacin have positive effects on body weight gain and feed intake during the early stages of growing, however, supplemental L- carnitine or L-carnitine ± niacin were not of benefit regarding the complete growth period. Also Cartwright (986) reported similar results when he used L-carnitine 0.05% of the diet from 5 to 7 weeks of age (at late stage of growth), then he found that growth performance of broilers, in terms of body weight and feed intake, was not affected L-carnitine supplementation. However, our results disagreed with Arslan et al., (2003 & 2004) where they found that L-carnitine administration via drinking 00 mg/l to Turkish native geese and 200 mg/l to Turkish native duck did not affect growth performance in ducks and geese, this disagreement could be related to the way of L- carnitine supplementation where they supplied it through drinking water, however ducks waste more water than they drink also they used different amount of L-carnitine on different breed of duck. Also Barker and Sell, (994); Leibetseder, (995); Buyse et al., (200) and Xu et al., (2003) reported that the supplementation of dietary L-carnitine did not affect body weight gain, feed intake, or feed efficiency of broiler chickens and young turkeys which dis agreed with our results but they were used different doses of L-carnitine on different species. Moreover the effect of dietary L-carnitine on improving performance traits was higher and longer in Mule ducks than ducks

5 however, limited comparative information could be found in the literature on the influence of dietary L-carnitine on different duck breeds. From data in Table () it was found that at 2 weeks old age ducks had body weight 9.26% higher than Mule ducks and this is logically as duck is a pure breed however Mule duck is across breed resulted from drake and Pekin duck so its weight is an average of his parents weight. Guy et al., (999); Davail et al. (2003) and Larzul et al., (2006) found that at 3 weeks of age of ducks had higher body weights than Mule ducks (P<0.05). Moreover ducks weight gain still high till 0 weeks old age while Mule ducks weight gain sharply decreased from 8 weeks old age, so marketing of Mule ducks should be at 8 weeks old age, however ducks marketing could be delayed to 0 weeks old age (Table 2). Supplementation of L-carnitine to duck did not affect carcass weight, dressing%, abdominal fat and body organs either as absolute weights or as a percentage of life weight except heart weight and percentage in ducks and pancreas percentage in ducks which were significantly higher in L-carnitine treatments (Table 4 and 5). These results similar to Arslan et al., (2003 & 2004) who found that L-carnitine supplementation via drinking water did not influence body organs weight in ducks or geese, also Lien and Hornga, (200); Celik and Ozturkcan, (2003) pointed out that abdominal fat weight, relative weight of abdominal fat, carcass weight and carcass yield of broilers was not significantly affected by diet supplementation. Sarica, et al., (2005) recorded non-significant effect of dietary L-carnitine on carcass weight, dressing percentage, abdominal fat and body organs relative values of Japanese quails. However Rabie and Szilagyi, (998); and Xu et al., (2003) reported that abdominal fat percentage of body weight was significantly reduced by adding L-carnitine. The increased heart weight and percentage with L-carnitine supplementation was observed by Buyse et al., (200) who found that addition of 00 mg/kg L- carnitine to the basal starter (containing 7.8 mg/kg L-carnitine) and finisher (containing 22.9 mg/kg L-carnitine) diets greatly increased absolute and proportional heart weights. ducks recorded higher carcass weight, dressing percentage, abdominal fat weight and 63 percentage compared to ducks, however, ducks had significantly higher gizzard and pancreas percentages of life weight compared to ducks, these results could be attributed to the significantly smaller life weight (denominator) of ducks as previously mentioned with nonsignificant difference in organs weights (gizzard and pancreas ) between the two breeds resulted in higher percentage of this organs in ducks. From data in Table (6) we found that carcass cuts weights or percentages of life weight did not significantly affected by dietary L-carnitine supplementation, Arslan et al., (2003) found similar results in Turkish native duck supplied by L-carnitine via drinking 00 mg/l. Moreover ducks recorded significantly higher (P<0.05%) thigh weight and percentage, shoulder weight and total fillet weight compared to ducks, it is possible to the significantly higher carcass weight of this breed as previously mentioned in Table 4. Chemical composition of liver and breast muscle didn t influence by addition of L-carnitine supplementation (Table 7), this results were in agreement with those reported by (Barker and Sell, 994; Rabie et al., 997; Rabie and Szilagyi, 998; Celik and Ozturkcan, 2003) that the supplementation of L-carnitine to the broiler diet did not significantly affect the dry matter, CP, and ether extract components of breast or thigh meat, also Sarica, et al., (2005) recorded that Levels of supplemental dietary L-carnitine did not significantly affect the dry matter or moisture, CP, and ether extract contents of the total edible meat (breast plus high meat) of 35-dold Japanese quail. Also chemical composition of breast muscles and liver did not differ significantly between and ducks, this results attributed by Larzul et al., (2006) where characteristics of the breast meat were studied on male Mule, Hinny and Pekin ducks after forced feeding. No significant differences were recorded between and Mule ducks in dry matter, lipid content and mineral content, however protein content was higher in ducks than Mule ducks but this difference may be related to the different conditions of the two experiments where they measure these contents after forced feeding, however our results recorded before overfeeding.

6 In conclusion, dietary L-carnitine 500 mg/kg ration can improve productive performance traits if used within the first 4 weeks of life, however after that age, its addition does not improve neither growth performance nor carcass characters. ducks responded to supplemental L-carnitine more efficient than ducks, moreover marketing of Mule ducks should be at 8weeks old age; however ducks marketing could be delayed to 0 weeks old age. Table. Least square means and their standard errors of the effect of breed, L-carnetine and their interactions on the body weight of and ducks. Biweekly body weight Item No. 2nd week 4th week 6th week 8th week 0th week 2th week ±4.7 b 208.2±3.86 a ±6.99 a ±9.4 a ±22.43 b ±32.5 b ±5.57 a 00.40±4.63 b ±27.23 b 397.9±50.38 b ±50.44 a ±42.93 a L-Carntine Control ±5.78 b 08.4±4.99 b ± ± ± ±46.33 L-carnitine ±5.56 a 32.75±20.27 a ± ± ± ±4.00 * L-Carntine Control ±6.47 b 5.96±8.2 a ±24.34 a ± ± ±46.95 L- carnitine ±5.89 b ±7.46 a ±2.23 a 350.2± ± ±40.43 Control ±7.07 ab 00.33±8.83 ab ±36.83 b ± ± ±56.47 L- carnitine ±8.44 a 99.86±2.99 b ±39.36 b 336.3± ± ±63.43 Values are means ± SEM. Means within the same column carry different superscripts are significantly different. 2nd weeks, body weight to the nearest grams at 2nd week of age ; 4th week, body weight to the nearest grams at 4th week of age ; 6th week, body weight to the nearest grams at 6th week of age ; 8th week, body weight to the nearest grams at 8th week of age ; 0th week body weight to the nearest grams at 0th week of age &2th week, body weight to the nearest grams at 2th week of age. Table 2. Least square means and their standard errors of the effect of breed, L-carnetine and their interactions on the weight gain of and ducks. Biweekly weight gain Item No. Hatch -2 week 2-4 week 4-6 week 6-8 week 8-0 week 0-2 week ±4.28 b ±0.62 a 277.0±0.48 a ±4.28 b 450.±7.34 b ±8.82 b ±4.89 a 698.8±5.07 b 03.26±20.04 b 52.±42.08 a ±3.63 a ±23.03 a L-Carntine Control ±5.58 b 83.84± ± ± ± ±22.39 L-carnitine ±4.98 a ± ± ± ± ±20.39 * L-Carntine Control ±5.74 b 95.87±4.2 a ± ± ± ±26.39 L-carnitine ±5.07 ab ±3.63 a ± ± ± ±26.76 Control ±6.29 a 7.80±9.35 b 03.52± ± ± ±33.94 L-carnitine ±7.34 a 683.6±22.59 b ± ± ± ±30.03 Values are means ± SEM.Means within the same column carry different superscripts are significantly different. Hatch -2 week, weight gain in grams from hatch to two weeks of age; 2-4 week, weight gain in grams from two weeks to four weeks of age; 4-6 week, weight gain in grams from four weeks to six weeks of age; 6-8 week, weight gain in grams from six weeks to eight weeks of age; 8-0 week, weight gain in grams from eight weeks to ten weeks of age &0-2 week weight gain in grams from ten weeks to twelve weeks of age. 64

7 Table 3. Least square means and their standard errors of the effect of breed, L-carnetine and their interactions on relative growth rate of and ducks. Biweekly growth rate Hatch-2 Item No. Hatch -2 week 2-4 week 4-6 week 6-8 week 8-0 week 0-2 week week ±.2 b 3.2±0.73 a 69.40±0.67 a 32.90±0.49 b 2.20±0.47 b 7.9± ±0.0 b ±0.33 a 06.60±.62 b 67.97±.05 b 43.62±.47 a 28.07±0.94 a 8.93± ±0.09 a L-Carntine Control ±.33 b 20.73±.7 a 69.58±0.87 a 39.57±.23 a 9.74± ± ±0. L-carnitine ±0.76 a 7.7±.87 b 67.77±0.88b 36.55±.7 b 20.08± ± ±0. * L-Carntine Control ± ± ±0.9 a 33.98± ± ± ±0.4 b L ±.09 carnitine 29.89± ±0.86 b 3.85± ± ± ±0.4 a Control ± ± ±.42 b 45.29± ± ± ±0.0 a L ±0.46 carnitine 04.67± ±.58 b 4.83± ± ± ±0.5 a Values are means ± SEM. Means within the same column carry different superscripts are significantly different. Hatch -2 week, relative growth rate from hatch to two weeks of age; 2-4 week, relative growth rate from two weeks to four weeks of age; 4-6 week, relative growth rate from four weeks to six weeks of age; 6-8 week, relative growth rate from six weeks to eight weeks of age; 8-0 week, relative growth rate from eight weeks to ten weeks of age; 0-2 week relative growth rate from ten weeks to twelve weeks of age& Hatch-2 week, relative growth rate from hatch to twelve weeks of age. Table 4. analysis of variance of the effect of breed, L-carnitine and their interactions on life weight, carcass weight and percentage of life weight, liver weight and percentage of life weight, abdominal fat weight and percentage of life weight and intestine weight and percentage of life weight of and ducks. Item L-carnitine Control L-carnitine * L- carnitine Life weight ± b ± a ± ±96. 4 Carcass weight ±5.2 8 b ± a ± ± Carcass % 63.92±. 02 b 69.7±0. 92 a 66.64± 65.74±. 79 Liver Weight 69.4±2.5 90± ± ±5.3 2 Liver %.63± ± ± ±0. 08 Abdomina l fat 4.83±3.3 0 b 57.00±. 50 a 29.83± ±9.4 9 Abdomin al fat % 0.36±0.0 8 b.6±0.2 4 a 0.66± ±0. 8 Intestine Weight 90.83± ± ± ± ± ± ±4.7.67±0..8± ± ±4.5 Control 4205±79.9 Moulor d L ± ± ± ±2..59± ± ± ±8.0 carnitine ± ± ±7.4.84± ±7.5.2± ±7 Musco Control 379± vy L- 5300± ± ± ±4.4.87± ±2..22± ±20 carnitine Values are means ± SEM. Means within the same column carry different superscripts are significantly different.. All weight measured in grams. Intestine Weight % 2.3±0. 3.4± ± ± ± ± ± ±

8 Table 5. analysis of variance of the effect of breed, L-carnitine and their interactions on gizzard, pancreas, spleen, proventriculus and heart weights and percentages of life weight of and ducks. Item Gizzard Pancreas Spleen Proventriculus Heart Weight % Weight % Weight % Weight % Weight % 77.07± ±0.5 a 9.66± ±0.0 a.64± ± ± ± ± ± ±4.3.46±0.06 b 7.8± ±0.0 b 3.9± ± ± ± ± ±0.05 L-carnitine Control 75.85± ± ± ± ± ± ± ± ± ±0.04 L-carnitine 73.39±3.3.59± ± ± ± ± ± ± ± ±0.03 * L-carnitine Control 83.22±.3.99± ± ±0.0 b.68± ± ± ± ±.04 b 0.85±0.02 a L-carnitine 70.92± ± ± ±0.0 a.6± ± ± ± ±.43 bc 0.79±0.04 a Control 67.00±4.9.45± ± ±0.02 c 4.04± ± ± ± ±3.07 c 0.64±0.06 b L-carnitine 78.33± ± ± ±0.0 bc 3.7± ± ± ± ±3.52 a 0.82±0.04 a Values are means ± SEM. Means within the same column carry different superscripts are significantly different.. All weight measured in grams. Table 6. analysis of variance of the effect of breed, L-carnitine and their interactions on carcass parts weights and percentages of life weight of and ducks. Item Thigh Shoulder Total fillet Fillet muscle Weight % Weight % Weight % Weight % ±8.72 b 7.20±0.7 b 90.83±4.55 b 4.53± ±2.22 b 8.34± ± ± ±0.49 a 8.6±0.22 a ±0.07 a 5.34± ±39.86 a 0.± ± ±0.56 L-carnitine Control ± ± ± ± ± ± ± ±0.38 L-carnitine ± ± ± ± ± ± ± ±0.5 *L-carnitine Control ± ± ± ± ± ± ± ±0.9 L-carnitine ± ± ± ± ± ± ± ±0.7 Control ± ± ±0 5.53± ± ± ± ±.54 L-carnitine 42.67± ± ± ±0. 555± ± ± ±0.4 Values are means ± SEM. Means within the same column carry different superscripts are significantly different.. All weight measured in gram 66

9 Table 7. analysis of variance of the effect of breed, L-carnitine and their interactions on breast muscle and liver chemical composition (dry matter%, water%, protein%and fat%) of and ducks. Item Breast muscle Liver Dry matter Water Protein Fat Dry matter Water Protein Fat 30.52± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±0.5 L-carnitine NO 32.05± ± ± ± ± ± ± ±0.5 YES 30.37± ± ± ± ± ± ± ±0.3 * L-carnitine NO 30.7± ± ± ± ± ± ± ±0.58 YES 30.33± ± ± ± ± ± ± ±0.36 NO 33.4± ± ± ± ± ± ± ±0.93 YES 30.4± ± ± ± ± ± ± ±0.6 Values are means ± SEM Means within the same column carry different superscripts are significantly different. 5. REFERENCES Atienzar, F.A., Jha, A.N The random amplified polymorphic DNA (RAPD) assay and related techniques applied to genotoxicity and carcinogenesis studies: a critical review. Mut. Res. 63: AOAC, Association of official analytical chemitcs, official method of analysis 7th Gaithersburg Marryland USA. Horwitz. Arslan, C., Citil, M. & Saatci, M Effects of L- carnitine administration on growth performance, carcass traits, blood serum parameters and abdominal fatty acid composition of ducks: Archi. Anim. Nutr. 57: Arslan, C., Citil, M. & Saatci, M Effects of L- carnitine administration on growth performance, carcass traits, serum lipids and abdominal fatty acid composition of geese: Rev. Méd. Vét. 55: Barker, D.L. & Sell, J.L Dietary carnitine did not influence performance and carcass composition of broiler chickens and young turkeys fed low- or high-fat diets: Poul. Sci. 73: Baumgartner, M. & Blum, R L-Carnitine in animal nutrition. In Vitamine und weitere Zusatzstoffebei Mensch und Tier (Vitamins and Other Supplements for Humans and Animals), pp [G Flachowsky and R Schubert, editors]. JenaGermany: Friedrich-Schiller Universita t. Brody, S Bioenergetics and Growth: Reinhold Publishing Corportion., New York. Buyse, J., Janssens, G.P.J. & Decuypere, E The effects of dietary L-carnitine supplementation on the performance, organ weights and circulating hormone and metabolite concentrations of broiler chickens reared under a normal or low temperature schedule: Bri. Poul. Sci. 42: Cartwright, A. L Effect of carnitine and dietary energy concentration on body weight and body lipid of growing broilers: Poul. Sci. 65(Suppl. ):2 29. Celik, L. & Ozturkcan, O Effects of dietary supplemental Lcarnitine and ascorbic acid on performance, carcass composition and plasma L- carnitine concentration of broiler chicks reared under different temperature: Arch Tierernahr Jour., 57: Davail, S., Rideau, N., Guy, G., Andre, J.M., Hermier, D., & Hoo-Paris, R Hormonal and metabolic responses to overfeeding in three genotypes of ducks: Comp. Bioch. Phys. 34: Elika, L., Ztrkcana, O., Nalb, T. C., Canacankatanb, N. & Kayrinb, L Effects of l-carnitine and niacin supplied by drinking water on fattening performance, carcass quality and plasma l-carnitine concentration of broiler chicks: Archi. Anim. Nutr. 57: French industry figures French industry website. Gropp, J.M., Schumacher, A. & Schweigert, F.J Recent research in vitamin nutrition with special emphasis to vitamin A, b-carotene and L- carnitine: In: Proceedings of the Meeting of the Arkansas Nutrition Conference, Fayetteville, Arkansas Poultry Federation, pp

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