Table 2.

Effect of folic acid in the animal.

Animal	Dose rate	Major findings	References
Laying hens	Basal diet added FA 4 mg/kg	Increased egg weight and egg mass, decreased serum glucose levels, and serum uric acid	Jing et al. [50]
Laying hens	Basal diet added FA 10 or 100 mg/kg	Increase egg and plasma folate concentrations and also decrease the transport of FA in the duodenum	Tactacan et al. [54]
Laying hens	Basal diet added 10 mg/kg of FA	Affects the activity of plasma homocysteine, methionine synthase, and hepatic serine hydroxymethyltransferase. And egg folate concentrations	Tactacan et al. [59]
Laying hens	FA added 4 mg/kg	Enriches the FA content of eggs	Dickson et al. [45]
Laying hens	Basal diet added with chromium yeast (150 mg ton−1) + FA (10 mg ton−1)	Increase in the feed conversion, decrease in feed consumption, and egg yolk cholesterol	Eseceli et al. [60]
Laying hens	Basal diet added FA 50 mg/kg	Increase the body weight of the newly hatched chicks	Terčič and pestotnik [41]
Laying hens	Basal diet added FA 24 mg/kg	It affects the cecum by reducing pathogenic bacteria	Bai et al. [30]
Laying hens	Basal diet added FA 5, 10, and 15 mg/kg	It affects egg yolks by increasing 5-MTHF content and egg production	Bagheri et al. [27]
Laying hens	Basal diet added 4 mg/kg of crystalline FA	Affect the accumulation of folate in eggs	Hebert et al. [45]
Laying hens	Basal diet added 2 and 4 ppm FA	Increased egg production	Krishnan [43]
Laying hens	Basal diet added BET (1,0 g/kg) and FA (1,0 mg/kg)	Increases in haugh units, egg weight, shell thickness, sperm motility, and decreased dead spermatozoa	Ezzat et al. [49]
Hepatocytes from new-hatched male chicks	The concentration of FA in the culture medium is 15 mg/L	Inhibits de novo fatty acid synthesis and promotes hydrolysis and exportation of triglyceride in primary chicken hepatocytes	Liu et al. [9]
Broilers	Basal diet added 200 mg L-ascorbic acid plus 1.5 mg FA/kg	Can improve the antioxidant status, growth, and health status of broilers under heat stress	Gouda et al. [25]
Broilers	2.0 mg/kg folate added to feed	Less significantly affect product performance and slaughter performance	Zhang et al. [12]
Broilers	FA (13.0 mg/kg), meth (0.25%), and B12 (0.15 mg/kg) were added to feed	Positive effect on FCR, egg weight, hatchability, and weight of DOC	El-Husseiny et al. [48]
Broilers	FA was added to the feed at 5 mg/kg and 10 mg/kg	Reduce fat accumulation by regulating gene expression	Zhang et al. [7]
Broilers	The basal diet was supplemented with 0.25, 1.25, 2.50, and 5.00 mg/kg−1 folate	Could regulate glucose and lipid metabolism in broilers	Wu et al. [11]
Laying quails	FA as much as 4 and 8 mg/kg added to the feed	Significantly increase FA content and egg yolk color	Sadegheymojarad et al. [21]
Turkey	Basal diet added FA 1–2 mg/kg	Increase the vitamin content in eggs, increase the weight of chicks, and their growth	Barroeta et al. [43]