Modulation of Physiologic Parameters in Molted Isa Brown Laying-Hens by Glutamine + Glutamic Acid Supplementation
ABSTRACT Feed costs are the main limiting factors in poultry industry and alternative sources of food and/or feed supplements to optimize the bird´s life cycle and to extend their production period need to be explored. This study evaluated morphometric parameters of the small intestine and gonadotropin transcript levels in Isa Brown laying hens supplemented with glutamine + glutamic acid (Aminogut®) during a second production cycle. Molting was induced and groups of 100 hens each, were supplemented with 0, 0.8, 1.6 or 2.4% Aminogut® in their diet. At the end of the experimental period, tissue sections from duodenum, jejunum and ileum were processed by the Hematoxylin-Eosin technique and samples from hypothalamus and hypophysis were collected for RT-PCR analysis of GnRH and GnRHR transcript levels. As results, the height of the intestinal villi of the duodenum and ileum was significantly (p<0.05) higher in hens supplemented with 0.8% and 1.6% Aminogut®, while in the jejunum, no significant differences were found. Hens treated with increased doses of Aminogut® tended to increase GnRH transcripts levels, whereas those of GnRHR tended to decrease proportionally. It is concluded that supplementation of Isa Brown laying hens during a second production cycle with Aminogut® developed increased villus height in duodenum and ileum that may promote better absorption of nutrients and potentially to increase the egg production. This study shows the importance of molecular techniques such as RT-PCR to support the biological effects of nutritional compounds on morphological parameters and hen productivity.