02 May 2023
Grape polyphenols (NuxaFen®) can replace synthetic vitamin E in standard and demanding dietary formulations.
INTRODUCTION
Dry grape extracts (Vitis Vinifera spp. Vinifera, NuxaFen®, Nuproxa Switzerland) contain high levels of polyphenols, including proanthocyanidins, which confer a high antioxidant capacity.
Polyphenols work as antioxidants by:
quenching free radicals
chelating metal ions that induce the production of free radicals,
and increasing the activity of antioxidant enzymes such as SOD, CAT and GPx.
Previous studies have shown that NuxaFen® can partially replace synthetic vitamin E in broiler diets without altering zootechnical performance (Dewez et al., 2022).

OBJECTIVE

Evaluate the capacity of NuxaFen® to partially or totally, replace synthetic vitamin E in broilers fed a diet with high levels of polyunsaturated fatty acids, Fe and metabolizable energy (ME).
MATERIALS & METHODS![]()
The study was conducted with the research service of ZOOTEST. Ploufragan and within a commercial barn (GAEC
de La Ville Gestin. Gestin 22640).

One thousand and twenty (1020) day-old ROSS-308 chicks (100% males) were weighed and randomly distributed among 60 pens (N=17 chicks / pen) and 6 treatments (T) (Table 1).
Treatments 1 and 4 were control diets supplemented with 50 mg/kg of vitamin E.
In T 2 and 5, 50% of vitamin E was replaced by 2.3 mg/kg NuxaFen®.
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and in T 3 and 6, 100% of vitamin E was replaced by
4.6 mg/kg NuxaFen®.
The replacement ratio was 1:11 (NuxaFen®: vitamin E) on a weigh basis, based on results from previous studies (Dewez et al., 2022).
| T4. T5 and T6 were higher in ME and contained 5% of linseed oil and 0.2% of FeS04 to increase the oxidative stress in the birds (challenged feeds). |
The experimental diets were based on wheat, corn and soybean meal and met the nutritional requirements of broilers.

The trial had a duration of 42 days.

Table 1: Treatment Description.

1ME levels for starter diets (1-14 d), growth (15-28 d) and finisher (29-42 d), respectively.
RESULTS

Broilers fed the challenged feeds (Diet B. Figure 1) achieved a lower body weight (BW) at 42 days, nevertheless the only significant difference (p < .05) was observed between T 1 and 3 (higher BW) compared to T6 (lower BW).
Within the type of feed, no differences (p > .05) were observed between treatments.
The lower body weight observed in birds fed the challenged feed was a consequenceof a reduction in feed intake (data not shown). |

Figure 1. Body weight at 42 days:

Diet A: standard diet; Diet B: high ME, with 5%linseed oil and 0.2% FeSO4
The feed conversion rate (FCR) was improved (p <.05) in the birds fed the challenged diet, likely due to the higher ME in these feeds (Figure 2). Among the type of diet, no differences (p > .05) were observed between treatments.


Other measurements recorded during the study, including antioxidant status of the birds and processing yields did not differ (p >.05) between feed type or treatments (data not shown).
Figure 2. Feed conversion rate at 42 days:

Diet A: standard diet; Diet B: high ME, with 5% linseed oil and 0.2% FeSO4.


Overall results show no difference in performance of broilers supplemented with synthetic vitamin E ar grape extract either with partial or full replacement.
CONCLUSIONS
| NuxaFen® can partially or totally replace synthetic vitamin E with a 1:11 ratio, without compromising zootechnical performance. |
REFERENCES 
Dewez et al. (2022). Comparative effect of partial vitamin E replacement with dry grape seed extract (Vitis Vinifera spp. Vinifera) on broiler performance and antioxidant status under stress conditions. World Poultry Congress, Paris.
Content produced by Nuproxa Switzerland Ltd
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