Global Veterinaria 7 (5): 468-477, 2011 ISSN 1992-6197 © IDOSI Publications, 2011 Corresponding Author: Ahmad Salahi, Department of Animal Science, Agriculture School, Islamic Azad University, Varamin-Pishva Branch, Varamin, Tehran, Iran. Mob: +98-9131434146, Fax: +98-2922034888, Email: ahmad.salahi2010@gmail.com. 468 Effects of in ovo Injection of Butyric Acid in Broiler Breeder Eggs on Hatching Parameters, Chick Quality and Performance Ahmad Salahi, Seyed Naser Mousavi, Farhad Foroudi, 1 1 1 Mozhdeh Moosanezhad Khabisi and Mojtaba Norozi 2 3 Department of Animal Science, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran 1 Department of Animal Science, Islamic Azad University, Kahnooj Branch, Kerman, Iran 2 Mahan Chicken Meat Complex, Tehran, Iran 3 Abstract: The experiment was conducted to evaluate the effect of butyric acid glyceride injection into amniotic fluid on hatching, chick quality, organs weight and performance parameters broiler breeder chick. From flock with 45 week age, 504 Ross 308 eggs with 66.5±0.5 g, in a completely randomized design with 3 treatment (including control or without injection, injection of Nacl 0.9% or positive control and 0.3% butyric acid injection), 4 replicate and 42 eggs on each replicate were selected. The results showed that butyric acid injection on chick weight at hatch day was not significant but chick yield was significant (P<0.05). Also there were significant differences in chick length and incubation duration (P<0.05), but there were not significant effects on hatchability and chick quality. Chick body weight at 10 day post hatch was effected by butyric acid injection (P<0.05) and butyric acid injection caused to increased 7.1 g chick weight on 10 day compare with control. Effect of butyric acid injection on small intestine and jejunum length on hatch day and yolk free body mass (YFBM) was significant (P<0.05) and butyric acid injected treatment had longer small intestine and jejunum length compare with control. Injection effect on breast weight was not significant, but on thigh weight, liver and heart weight at 7 day post hatch was significant (P<0.05). Duodenum weight at hatch day was affected by injection (P<0.05). We can conclude that butyric acid injection on chick weight at hatch day was not significant but this effect on 10 day was significant, also increased small intestine length and this topic help to increase consumption, absorption of feeds and increased body weight. Key words: In ovo injection % Butyric acid % Chick quality % Incubation parameters % Broiler breeder eggs INTRODUCTION the lower doses [7]. Mahdavi and Torki [8] showed that Butyric acid is a medium-chain fatty acid with four length in compare with control group [8]. The positive carbons (C4), generally absorbed from the first part of effect of butyric acid was not observed in chickens raised gastrointestinal [1]. Butyric acid had dual effects on under clean environment [8]. Also Mono butyric acid bacterial (antibacterial) control and promotion of intestine glycerides were reduced mortality rate in birds infected villi [1, 2]. It is believed that dietary supplement of butyric, with Eimeria spp strains, but had no effect on the normal propionic and acetic acid increases the production rate of and non-infected birds [9, 10]. crypts cells in the rat intestinal villi [3]. Prydw et al. [4] Antongiovanni et al. [11] reported that dietary reported that butyric acid is used as an energy source for addition of mixed triglyceride of butyric acid (mono, 2 and growth and development of intestine epithelial cells [4] triglycerides), increased liver weight at slaughter and and increased ileum villi length in pigs [5]. Dietary could be improved feed conversion ratio. However supplementation of butyric acid improved broiler addition of 0.2% of this mixture to broiler diets, decreased performance and carcass parameters [6] and reduced the villi length and increased microvilli length and crypt depth expression of genes involved in Salmonella invasion at of jejunum [11]. dietary addition of 3g/kg butyric acid improved intestine