The effects of an organic rearing system and dietary supplementation of an essential oil mixture on performance and meat yield of slow-growing broilers in two seasons

Abstract

In this study, performance and carcass characteristics of slow-growing broiler chicks, reared in organic or conventional systems, and fed a diet with an essential oil mixture (EOM, 48 mg/kg diet), were evaluated in the autumn and spring seasons. The rearing system affected several performance indices, including body weight, feed intake and feed conversion ratio (FCR), but not mortality, within a high statistical significance at 42 and 81 days of age. However, this was observed only from 1 to 42 days in the spring trial. Dietary administration with EOM worsened the FCR at 42 and at 81 days of age in the autumn trial, but not in spring. Organically reared slow-growing chickens consumed less feed mixture per unit of body weight gain, but attained a higher final weight compared with those kept indoors. However, the effect was more pronounced in autumn, which displayed cooler temperatures and robust plant cover availability (i.e. lucerne and trifolium). The carcass yield and cut-up carcass yield were not affected by the rearing system, but EOM diet supplementation increased breast yield only in the spring. The results suggest that autumn conditions promote efficient organic chicken production in the subtropical climatic zone. The amount of herbage consumed represented up to 10% and 3% of the birds' daily protein and ether extract requirements, respectively. Supplementing the diet with a mixture of plant essential oils did not support the hypothesis that phytogenic compounds may favourably affect gut function and poultry performance.

Effects of two sources of Mexican oregano oil on performance, blood profile, carcass variables, and meat of broilers

“…In the current study, essential oil extract from Poliomintha longiflora (PLG) presented FI similar to the control group, and similar to results of Khattak et al (2014), who demonstrated no change in broiler FI when evaluating mixtures of essential oils. Similar results were obtained by Küçükyılmaz et al (2014) in BW and FI in the period of 0-42 days when evaluating 48 mg of a dietary OEO mixture (oregano, sage, myrtle, fennel, and citrus peel)/kg of feed.…”

“…In addition, diets supplemented with MOO in the current study improved carcass pieces compared with the control group. In contrast, Küçükyılmaz et al (2014) found no differences in carcass yield, thighs, breasts, and wings when evaluating 28.8 mg of carvacrol/kg of feed over 81 days, but their results were higher than those of the current study. Kırkpınar et al (2014) found no influence on carcass yield, breasts, and thighs when evaluating 150 and 300 mg of OEO/kg in diets.…”

“…A number of researchers have evaluated performance and meat quality of broilers given plant extracts (Akbarian et al, 2013;Sharifi et al, 2013;Cho et al, 2014;Park et al, 2014;Starčević et al, 2015) and OEO (Hong et al, 2012;Khattak et al, 2014;Kırkpınar et al, 2014;Küçükyılmaz et al, 2014;Ghazi et al, 2015;Silva-Vázquez et al, 2015;Sun et al, 2015;Ghazanfari et al, 2015;Hashemipour et al, 2016;Peng et al, 2016;Reyer et al 2017;Chowdhury et al, 2018), demonstrating their influence on feed intake, growth enhancement, blood parameters, and meat quality. Silva-Vazquez et al (2017) indicated that Greek (Origanum vulgare L. ssp.…”

Performance, blood parameters, and carcass yield of broiler chickens supplemented with Mexican oregano oil

“…Feed intake decreased in the antibiotic treatment group. Similar results were obtained by Cabuk et al (2006) and Küçükyılmaz et al (2014).…”