Influence of dietary olive paste flour on the performance and oxidative stress in chickens raised in field conditions

Abstract

Olive oil contains a variety of antioxidants, including vitamin E. Its consumption protects against oxidative stress, which is involved in many pathological conditions, affecting animals’ development and their general welfare. The present study aimed to investigate the effect of olive paste flour (OPF) on the antioxidant status and performance of broiler chickens raised in field conditions. Total of 18.000 broilers was randomly allocated in equal numbers in two poultry houses. The chickens were grouped according to their diet as follows: Control group: chickens fed commercial poultry feed, and OPF group: chickens fed control dietsin the starter period, but they got a supplement of OPF in grower, and finisher 1 and 2periods, respectively. The birds were raised under identical field conditions (ventilation, vaccination, lighting, etc.). Antioxidant status was assessed by measuring the concentration of vitamin E in plasma, as well as the total antioxidant capacity (TAC) in plasma and muscle tissue. According to the statistical analysis of the results, the addition of OPF to chickens’ diet significantly enhanced plasma α-tocopherol concentration (p≤0.05). TAC did not show any significant differences in chicken plasma nor muscle tissue(p>0.05).Feed intake (FI) was higher in OPF group, while Body weight (BW) was lower. Liveability was similar for the two groups. The feed conversion ratio (FCR) was higher, and the European production efficiency factor (EPEF) was lower in broilers of the OPF group compared to those of the control group.Samples of roasted breast from chickens of both groups were used for organoleptic characteristics evaluation. Results showed that samples of the OPF group smelled more intensely and were more tasteful than those of the control group.However, other organoleptic characteristics did not differ. In conclusion, the results demonstrated that although the addition of OPF to chickens’ diet can cause growth retardation, it can significantly increase the plasma α-tocopherol concentration. Further studies are needed to optimize the concentration of OPF in poultry feed in order to avoid growth retardation or even to promote growth in broiler chicks.

Growth Performance, Gut Health, Welfare and Qualitative Behavior Characteristics of Broilers Fed Diets Supplemented with Dried Common (Olea europaea) Olive Pulp

“…However, despite the similarities in BWG during this time period, only the chicks that consumed diets with 6% OP managed to achieve similar BW with control chicks. Increased feed intake in broilers fed finisher diets with 5% OP have also been recorded in previous reports [45]. During the last two weeks of the finishing period, considerable differences of FCR were recorded among groups.…”

“…The results of this investigation concerning overall growth performance are in agreement with those observed by other researchers who evaluated the in feed inclusion of OP in broilers' diet, at various incorporation rates such as 5% and 10% [25,38,39,46], 2%, 4%, 6% and 8% [40], 5% [42,43], 2.5%, 5% and 7.5% [36] and 6% [37]. On the other hand, lower BW at slaughter, increased feed intake and FCR in broilers fed grower and finisher ratios containing 2.5% and 5% olive paste flour respectively compared to controls, was reported by Fotou et al [45]. Moreover, decreased FC [37,43,46], deterioration of FCR [37,[41][42][43], decreased BWG [36,37] and final BW [36,37,43] of broilers fed diets supplemented with OP at rates of 8% [41,42], 3% and 9% [37], 10% [36,43], 15% [43] and 20% [46] compared to control chicks have been previously documented.…”

“…Moreover, decreased FC [37,43,46], deterioration of FCR [37,[41][42][43], decreased BWG [36,37] and final BW [36,37,43] of broilers fed diets supplemented with OP at rates of 8% [41,42], 3% and 9% [37], 10% [36,43], 15% [43] and 20% [46] compared to control chicks have been previously documented. The deterioration of OP fed broilers' productive traits in former reports has been attributed to the high crude fiber content of OP, and consequently OP diets that have been shown to negatively affect nutrient utilization [36,43,45]. Finally, Saleh et al [44] observed higher BWG in broilers with 35 days of age that consumed diets containing 4% OP compared to control chickens.…”

“…OP has been formerly used at various incorporation rates (2-20%) in broilers' diets in numerous studies with promising though not always consistent findings regarding birds' performances [25,[36][37][38][39][40][41][42][43][44][45]. In general, doses up to 10% do not seem to adversely affect broiler growth [25,[38][39][40]43], meat quality [41,45] and health parameters [40,42,44]. On the other hand, higher dietary levels of OP have been shown to impair body weight gain, feed conversion ratio and food consumption of broilers [36,43,46].…”

Effect of Farming System Type on Broilers’ Antioxidant Status, Performance, and Carcass Traits: An Industrial-Scale Production Study

“…The DPPH assay was carried out to evaluate the total antioxidant capacity (TAC) of the samples, as previously described by Fotou et al [19]. A DPPH reference sample was made by mixing (500 µL) DPPH solution (stock DPPH solution: 0.1 mM DPPH in methanol) with (500 µL) sodium phosphate buffer (10 mM, pH 7.4).…”