Spontaneous Intake and Long-Term Effects of Essential Oils After a Negative Postnatal Experience in Chicks

Abstract

The postnatal period is critical for broiler chicks as they are exposed to potentially stressful environmental changes in the hatchery and during transportation to the rearing houses. The ability of broiler chicks to spontaneously drink essential oils (EO) to mitigate the effects of a negative postnatal experience was tested. Chicks were placed in the rearing facility either immediately (C group), or after a 24 h-delay period (D group) to mimic a delay in transportation possible under commercial conditions. In experiment 1, each group had access to either water only or to water and one EO (cardamom, marjoram, or verbena) from D1 to D13. Verbena EO intake was higher in the D group than in the C group from D1 to D6 and cardamom EO intake was lower in the D group than in the C group from D6 to D13. In experiment 2, half of the groups had access to water only and the other half had both water and the three EO simultaneously. Chicks from D and C groups chose the EO similarly except for cardamom EO with a lower intake being observed in the D than in the C group from D6 to D12. The delayed placement of the D group reduced chicken growth until 34 days of age and temporarily increased the feed conversion ratio, but did not affect their welfare or the prevalence of health disorders. The EO intake did not mitigate the growth reduction in D group chicks, but did mitigate the reduced Pectoralis major muscle yield. In conclusion, chicks were able to make spontaneous choices regarding EO intake according to their postnatal experience when EO were presented individually, but not when presented simultaneously as in our experimental design. The EO intake only partially mitigated the decrease in chicken performance after the negative postnatal experience.

Spontaneous intake of essential oils after a negative postnatal experience has long-term effects on blood transcriptome in chickens

“…This study presents immediate and long-lasting effects of a delayed placement of chickens considered as a negative postnatal experience, mimicking early-life stresses encountered in poultry production, and the potential beneficial effects of EO intake on blood physiological parameters and gene expression profiling of chicken blood cells. In a previous study, we showed that chicks spontaneously chose to consume EO or not, according to their postnatal experience when different EO were presented individually 10 .…”

“…MEF2A is also known to influence muscle development and has been described in chicken 26 . Thus the MEF2A pathway may be activated to counter the observed decrease in P. major muscle yield observed in the Delayed chick group 10 .…”

“…Essential oils (EO). Cardamom (Elettaria cardamomum) (1480CQ, batch S12A, Herbes et Traditions, Comines, France), marjoram (Origanum majorana) CT thujanol (2507CQ, batch S12D, Herbes et Traditions), and lemon verbena (Lippia citriodora) (FLE094, batch H181013MA, Florihana, Caussols, France) were chosen based on the properties of their major components and on our previous study which showed spontaneous intake and long-term effects after a negative postnatal experience in chicks 10 . Each EO was diluted in water (0.001%), mixed and shaken vigorously before being made available in a drinking bottle.…”

“…The chicks (Hubbard Classic, Quintin, France) were either placed immediately in pens in the rearing facility after their removal from the incubator (Control group, C, n = 192) or they were removed and subjected to 24 h of negative experience before being placed in pens (Delayed group, D, n = 192). This delayed group was deprived of both food and water and subjected to irregular movement and various room temperatures 10 . Half of the chicks (six pens each for C and D groups) had access to water only in four bottles (W-C and W-D groups).…”

Short cold exposures during incubation and postnatal cold temperature affect performance, breast meat quality, and welfare parameters in broiler chickens

“…Because the thermoregulatory system of chicks is immature at hatching ( Tzschentke, 2007 ), they remain very sensitive to postnatal cold temperatures during the first days of breeding ( Collin et al., 2003 , Mujahid and Furuse, 2009 ). Environmental conditions during the perinatal period are considered critical for later performance and fitness of chickens ( Guilloteau et al., 2019 ). Especially, brooding chicks at low temperatures (26.7°C vs. 32.2°C) results in a decreased feed efficiency and increased mortality rate ( Renwick and Washburn, 1982 ).…”