The Effect of Thyme Extract on Growth Performance, Digestive Organ Weights and Serum Lipoproteins of Broilers Fed Wheat-Based Diets

Abstract

The effect of the thyme extract and wheat form of the diet on performance, digestive organ weights and serum lipoproteins was studied in 320 male day old (ROSS 308) chicks. From 1 to 42 d of age, 8 diets arranged factorial with 4 thyme extract level (0.0, 0.2, 0.4 and 0.6%) and 2 wheat forms (ground vs whole) was used. Each treatment was replicated 4 times (10 birds per replicate). Thyme extract had no significant effect on body weight gain, feed intake and feed conversion ratio irrespective of wheat form used over whole trial period (1-42 d). From 1 to 21 d of age, broilers fed the whole wheat diet grew faster than the broilers fed ground wheat based diet (609.06 vs 573.34 g). Relative abdominal fat and gizzard weight was significantly higher (P<0.05) in birds fed the whole wheat diets. Two-way interaction between thyme extract and wheat form were observed for total cholesterol, LDL-cholesterol, HDL-cholesterol and very-low-density lipoprotein (VLDL) in the experiment. The results showed that the extract had no effect on performance of broilers irrespective of wheat form used. Relative gizzard weight was higher (P<0.05) in birds fed the whole wheat diets, but an increase in abdominal fat should be taken into account for carcass quality and processing. The predominant effect of thyme extract on lowering lipid levels in broilers fed on wheat based diets was on triglyceride rather than on cholesterol concentrations.

Thyme oil (Thyme vulgaris L.) as a natural growth promoter for broiler chickens reared under hot climate

“…The present results are in line with those reported by Abdulkarimi et al (2011), who found that thyme decreased liver weight due to bile acid deconjugation, and thus reduced fat absorption (Pourmahmoud et al 2013). …”

“…On the other hand, Hosseini et al (2013) and Fallah and Mirzaei (2016) concluded that thyme powder at 1, 1.5 and 5 g/kg diet did not affect the growth performance of broilers, and the hot water extracted thyme administered at 5g/l did not affect the growth performance of broilers during 1-21 days of age (Sadeghi et al 2012). Another study with broilers indicated that, thyme extract added at 0.2, 0.4 and 0.6% to the broiler diet did not affect BWG, feed intake and FCR during 1-42 days of age (Pourmahmoud et al 2013;Hady et al 2016). Thus, these contradictions could be attributed to the thyme product, e.g.…”

“…powder, extract or oil, the composition of the basal diet, and the environmental, hygienic conditions and animal age. In general, growth promoters had less favourable effects when animals were fed highly digestible diets or were raised in optimal environmental conditions (Bovera et al 2012;Pourmahmoud et al 2013;Ma sek et al 2014;Attia et al 2016).…”

“…It was demonstrated that thymol and carvacrol concentrations from 100 to 1000 ppm displayed a positive effect on broiler production (Hosseini et al, 2013;Pourmahmoud et al 2013) and on blood metabolites and immune responses (Fallah & Mirzaet 2016). The difference in results cited in literature regarding the effect of thyme on animal performance may be due to the different thyme products used in the trials (oil, powder or different extracts), emphasising the need for continued research.…”

Prebiotics, probiotics and thyme (Thymus vulgaris) for broilers: performance, carcass traits and blood variables

“…This is in agreement with the findings by Aami-Azghadi et al (2010) and Navidshad et al (2010); similar amino acids uptake could be hypothesized between control and experimental groups (Rostagno et al, 1995). In the present study, feeding thyme essential oil at 1 g/Kg reduced relative weight of thighs, wings and back thoracic vertebrae, but did not influence the relative weight of internal organs, which is in agreement with the results obtained by Najafi and Torki (2010) and Pourmahmoud et al (2013). These authors found that supplementation of broilers diets with thyme essential oil (0.2 g/Kg) or thyme extract (up to 6 g/Kg) had no effect on the relative weight of internal organs.…”