Abstract: The objective of this experiment was to determine the effects of dry tomato pulp on egg yolk pigmentation and some egg yield charecteristics of laying hens. A total number of 75 Lohman brown layers, with 36 week old of age at the beginning of the experiment, was distributed in a completely randomized experimental desing into 5 treatments, with three replicates of 5 hens each. Dry tomato pulp had a significant effect on the Final Body Weigth (FBW), Feed Intake (FI) and Feed Conversion Ratio (FCR) whereas dry tomato pulp has no significant effect on the egg yield. Dry tomato pulp had a significant effect on the egg weight and egg shape index whereas dry tomato pulp had no significant effect on shell weight, shell thicknes and shell strength. Dry tomato pulp had a significant effect on egg yolk inedx and roche color fan value whereas dry tomato pulp had no significant effect on the egg ypolk weight, albumen index and haugh unite. Dry tomato pulp had a significant effect on likopen and beta-caroten contents of egg yolk. As a conclusion dry tomato pulp had a significant effect on the internal and extarnal egg quality charecteristics. Dry tomato pulp up to 20% can be used in laying hen diets.

INTRODUCTION

It is well estabilished that the egg yolk color is one of the very important factors for markrtiing in many countries. Recently some feed additives and ingredients have been used to manipulate and obtain for the requested level of pigmentation in egg yolk color (Santos-Bocanegra et al., 2004; Samli et al., 2005; Hasin et al., 2006; Jafari et al., 2006; Nobakht and Safamehr, 2007).

The dry tomato pulp is the one of the feed ingredent, which has been widely used to manipulate the pigmentation in egg yolk color of laying hens. It was also suggested that dry tomata pomace can be used as a protein source due to high protein content (Elloitt et al., 1981).

However, the information about the effects of dry tomato pulp on egg yolk pigmentation and some egg yield charecteristics of laying hens is stil limted. Therefore, the objective of this experiment was to determine the effects of dry tomato pulp on egg yolk pigmentation and some egg yield charecteristics of laying hens.

MATERIALS AND METHODS

A total number of 75 Lohman white layers, with 40 weeks old of age at the beginning of the experiment, was distributed in a completely randomized experimental desing into five treatments with three replicates of 5 hens each. Birds recived water and experimental diets (Table 1) ad-libitum during the experimental period.

The performance characteristics of laying hens (feed intake, feed conversion ratio and egg yield), egg internal qualities (egg yolk weight, albumen index, egg yolk index, haugh unite, roche color value), eggs external quality (egg weigth, shell weigth, shell strength, eggshell thicknes and egg shape) were determined.

Statistical analysis: One-way Analysis of Variance (ANOVA) was carried out to compare performance characteristics, egg internal qualities and eggs external qualities of egg using General Linear Model of Statistica for Windows. Significance between individual means was identified using the Duncan multiple range test. Mean differences were considered significant at p<0.05.

Table 1:	Ingredients and chemical composition of experimental diets (as fed basis)
*Vitamin premix (per 2.5 kg): 12,000,000 I.U. vitamin A, 2,400,000 I.U. vitamin D3, 30,000 mg vitamin E, 2500 mg vitamin K3, 3 000 mg vitamin B1, 7000 mg vitamin B2, 40,000 mg niacin, 8000 mg calcium-d-pantothenate, 4000 mg vitamin B6, 15 mg vitamin B12, 1000 mg folic acid, 45 mg d-biotin, 1500 mg canthaxantin, 500 mg apocarotenoic asit ester, 125,000 mg colin chloride, 50,000 mg vitamin C, 80,000 mg manganez, 80,000 mg Iron 60,000 mg zinc, 8000 mg cupper, 200 mg cobalt, 500 mg iod, 150 mg selenium ve 10000 mg antioxidant

Table 2:	The effects of dry tomato pulp on hen performance of laying hens
abcRow means with common superscript do not differ (p>0.05), FBW: Final Body Weight (g); FI: Feed Intake (g/bird/day); FCR: Feed Conversion Ratio (g feed/egg weigth)

RESULTS AND DISCUSSION

The effects of dry tomato pulp on hen performance of laying hens are given in Table 2. As can be shown from Table 1 dry tomato pulp had a significant effect on the FBW, FI and FCR, whereas dry tomato pulp has no significant effect on the egg yield.

FCR and egg yield obtained in the current experiment is considerably lower than that obtained by Nobakht and Safamehr (2007) but consistent with finding of Jafari et al. (2006).

The effects of dry tomato pulp on external egg charecteristics of laying hens are given in Table 3. As can be shown from Table 3 dry tomato pulp had a significant effect on the egg weight and egg shape index whereas dry tomato pulp had no significant effect on shell weight, shell thicknes and shell strength.

The feed intake, egg weight and shell weight obtained in the current experiment is considerably higher than Jafari et al. (2006) but consistent with finding of Nobakht and Safamehr (2007). The shell thickness obtained in current experiment was compareble with findings of Jafari et al. (2006) and Nobakht and Safamehr (2007).

The effects of dry tomato pulp on internal egg charecteristics of laying hens are given in Table 4. As can be shown from Table 4 dry tomato pulp had a significant effect on egg yolk inedx and roche color fan value whereas dry tomato pulp had no significant effect on the egg ypolk weight, albumen index and haugh unite. The haugh unite obtained in the current experiment is considerably lower than that obtained by Jafari et al. (2006). The roche color fan value obtained in the current experiment was considerably higher than that obtained by Jafari et al. (2006).

Table 3:	The effects of dry tomato pulp on external egg charecteristics of laying hens

Table 4:	The effects of dry tomato pulp on internal egg charecteristics of laying hens

Table 5:	The effects of dry tomato pulp on Likopen and β-caroten contents of egg yolk (mg/100 g)
abcRow means with common superscript do not differ (p>0.05)

The effects of dry tomato pulp on Likopen and β-caroten contents of egg yol kare given in Table 5. As can be shown from dry tomato pulp had a significant effect on likopen and beta-caroten contents of egg yolk.

CONCLUSION

As a conclusion dry tomato pulp had a significant effect on the internal and extarnal egg quality charecteristics. Dry tomato pulp up to 20% can be used in laying hen diets without any adverse effects.