AUTHOR=Cornescu Gabriela Maria , Panaite Tatiana Dumitra , Untea Arabela Elena , Varzaru Iulia , Saracila Mihaela , Dumitru Mihaela , Vlaicu Petru Alexandru , Gavris Teodor 

TITLE=Mitigation of heat stress effects on laying hens' performances, egg quality, and some blood parameters by adding dietary zinc-enriched yeasts, parsley, and their combination

JOURNAL=Frontiers in Veterinary Science

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1202058

DOI=10.3389/fvets.2023.1202058

ISSN=2297-1769

ABSTRACT=The study aimed to experiment natural, handy and efficient nutritional solutions to prevent and mitigate negative effects caused by environmental heat stress and to be applied to large-scale laying hen industry.
A three weeks trial was conducted on 128 laying hens TETRA-SL LL (50 weeks of age) housed in 8 cages/group, 4 laying hens/cage, 32 laying hens/group, under heat stress conditions (34±1°C). The basal diet on corn and soybean meal was formulated to be isocaloric and isonitrogenic. Compared to Control group diet (C), experimental groups: E1 included 1% Zn-enriched yeast; E2 included 2% parsley and E3 included 1% Zn-enriched yeast combined with 2% parsley with the objective of mitigating heat stress effects.
A statistically significant (p < 0.05) average egg weight was noticed on E2 and E3 compared to Control group, and also during the 1st week compared to the 2nd and the 3rd experimental weeks. Average daily feed intake values were highly significant (p < 0.001) on E3 group compared to Control, E1, E2, and on the 2rd week compared to the 3nd experimental week (p < 0.021). Feed conversion rate was highly significant (p < 0.001) during the 2rd and the 3nd experimental weeks compared to the 1st week. The average daily egg production was highly significant (p < 0.001) within 1st week compared to the 2nd and 3rd weeks. A highly significant (p < 0.001) yolk coloration was noticed on E2 and E3 groups. The malondialdehyde (MDA) concentration decreased significantly (p < 0.05) to all experimental groups compared to Control group during the 14th and 28th days of storage.