Printer Friendly

Effect and mechanism of glutamine on productive performance and egg quality of laying hens.


Glutamine, a semi-essential or conditionally essential amino acid, has two mobilizable N groups in its structure (Smith, 1990); it is also the amino acid maximally utilized in the intestine of healthy animals (Windmueller, 1980). Recently, Gln has come to be regarded as an essential amino acid for the gut in some species of animals when their body is in some specific physiological or developmental conditions, such as infections and injuries (Van der Hulst et al., 1996; Newsholme, 2001). Numerous observations indicated that Gln administration could suppress intestinal inflammation, protect intestinal mucosal structure and reduce mucosal apoptosis after injury in rodents (Sukhotnik et al., 2007; Kessel et al., 2008). Exogenous Gln had the effect of antioxidant protection for rats with the implanted tumor (Kaufmann et al., 2007) and mice with dystrophic muscles (Mok et al., 2008). As a precursor of Glutathione (GSH), Gln also showed its anti-inflammatory and anticancer effects by up-regulating the gut GSH metabolism in the post-sepsis or murine models of asthma (Kaufmann et al., 2008; Singleton et al., 2008), containing the spread of Escherichia coli from the intestine to such organs as the liver, lung, and spleen (de Oliveira et al., 2006), and lowering the mortality of i.p. Escherichia coli-challenged rats (Inoue et al., 1993). In addition, Gln was a necessary precursor for molecular synthesis, such as DNA and protein (Ardawi, 1983). Glutamine could synthesize a variety of amino acids to accelerate protein synthesis through deamination and transamination (Boza et al., 2001), which thus partially prevented animal nutrition deficiency. Glutamine stimulated protein synthesis could improve nitrogen balance, which was effective against the hurt from feed restriction and illness (Yeh et al., 2001; Johnson et al., 2003). Glutamine availability could modulate glucose homeostasis during and after exercise, implying that Gln was good for post-exercise intake (Iwashita et al., 2005). Therefore, it is quite important to ensure adequate intakes of this amino acid in order to meet the increased physiological demands of laying hens.

Many studies investigated the effects of Gln supplementation in the diet of livestock and poultry (Lackeyram et al., 2001; Doepel et al., 2006; Jafari et al., 2006; Fischer da Silva et al., 2007a; Murakami et al., 2007; Wang et al., 2008). However, there has been no research reported on Gln supplementation in the diet of laying hens. In this study, the effects and the mechanism of Gln on productive performance, egg parameters, hormone secretion, and the development of duodenum and oviduct in laying hens were investigated for the first time.


Experimental design and treatments

A total of 400 Lingnan Yellow laying hens with almost the same BW were collected from a commercial breeding company (Donglian, Shaoguan, China), and randomly assigned into four groups, with 100 laying hens in each group. The hens were fed daily with a commercial layer diet and water ad libitum before the 6-week study. Both the ingredients and the nutrient composition of the basal diet formulated in accordance with the NRC requirement (1994) were shown in Table 1. All data were measured except for metabolic energy (ME).

The diets were respectively supplemented with four levels of Gln: the diet with 0% of Gln was set as control group, and those with 0.2%, 0.4%, and 0.8% Gln were set as treatment groups. The diet of 120 g per bird was provided daily (considering 5% excess of requirement), and clean drinking water was supplied ad libitum during the 6-week feeding period. And the birds were exposed to a period of 16-hour (16L + 8B) incandescent light each day. Temperature and ventilation were controlled. The temperature was set at 25-30[degrees]C throughout the experiment.

Sample collection

Daily feed intake was recorded, and daily egg production and individual egg weight were recorded to determine the egg mass production (egg production x egg weight/100, g/h/d); moreover, feed conversion efficiency (feed intake/egg mass production) was calculated during the 6-week feeding period.

Eggs from each group of laying hens were collected at the end of the feeding period for egg quality measurement (egg weight, egg shape index, eggshell weight, eggshell thickness, yolk weight, yolk index, yolk color, and Haugh unit). Both the egg shape index and the yolk index were calculated with a micrometer. The Haugh unit reading was determined by the height of albumen measured with a micrometer. The Haugh unit was calculated with the following Haugh formula (Elsen et al., 1962): Haugh unit = 100 log (H-1.7 [W.sup.0.37] + 7.57), where H = height, and W = weight of the egg. When eggshell density was calculated (eggshell weight per surface area), eggshells were dried in a microwave oven and weighed in grams. The surface area of the egg was calculated from the weight of the egg with the formula S = 4.67 [G.sup.2/3] (Paganelli et al., 1974), where S = surface area, and G = egg weight. The eggshell density (mg/cm) was calculated by dividing eggshell weight by the surface area. The egg color was measured with the Roche shade selection fan. Moreover, the eggshell breaking strength was measured with the eggshell strength meter (a product of FHK Company, Tokyo, Japan) which forced the egg until the shell broke.

Blood collection and analysis

Blood samples (8.0 ml) from each individual laying hen were collected from the heart with sterilized syringes and needles at the last day of the feeding period and then centrifuged (4000 rpm) for 6min. Then the obtained serum samples were stored at -70[degrees]C for further analysis. The levels of [T.sub.3], [T.sub.4], LH and FSH in serum were analyzed with the method of radio-immunity (RI). The assay kits of hormones were provided by Beijing North Institute of Biological Technology (20a Panjiamiao, Fengtai District, Beijing, China).

Duodenum and oviduct morphometry

Three birds per replicate were killed with exsanguination. Segments of approximately 4 cm were obtained from the region of the pylorus to the distal portion of the duodenal loop, and from the tubal isthmus. According to the method described by Becak and Paulete (1976), collected segments were placed on polystyrene sheets, opened longitudinally, washed in saline solution, fixed in Bouin's solution for 24 h, and processed until paraffin embedding. Each fragment was submitted to semiseriate cuts (5 mm thick) and stained using the hematoxylin-eosin method.

In the morphometric study, images were captured using a light microscope and a system that analyzes computerized images. The height and width of 30 villi, the depth of 30 crypts, and the thickness of 30 muscular layers were measured from each replicate per segment.

Statistical analysis

The experiment was conducted under a completely randomized design. The SAS (Statistical Analysis System, SAS Institute Inc, Cary, NC, USA, Version 9.1.3) software package was used for all statistical analysis. Duncan's multiple range test (p<0.05) was used to test the significance of difference between means. All data were expressed as means[+ or -]SD. Differences were considered significant at the level of p<0.05.


The results of egg production, egg mass, feed intake and feed conversion efficiency of the laying hens fed with the diets supplemented with 0%, 0.2%, 0.4%, and 0.8% Gln were shown in Table 2. After a feeding period of six weeks, the productivity of laying hens was not significantly (p>0.05) affected by adding 0.2% and 0.4% Gln in diet; however, egg production of laying hens (p<0.01), egg mass (p<0.05), feed intake (p<0.05), and feed conversion efficiency (p<0.05) were significantly improved by 0.8% dietary Gln treatments.

The effect of Gln on egg quality in laying hens was also shown in Table 2. Egg weight, yolk weight, shell weight, egg shape index, shell density, shell thickness, shell breaking strength, yolk index, yolk color, and Haugh unit did not differ significantly among laying hens fed with Gln supplemented diets comparing with the control group (p>0.05).

The hormone levels of laying hens in different treatments were shown in Table 3. Treatment of 0.2% dietary Gln had little effect on hormone secretion (p>0.05); 0.4% Gln in diet could increase the levels of hormone secretion but not significantly (p>0.05). LH (p<0.01), FSH (p<0.01), [T.sub.3] (p<0.05) and [T.sub.4] (p<0.05) contents in blood increased significantly when the hens were fed with 0.8% Gln in diet.


The intestinal morphology of the duodenum in different treatments was shown in micrographs A, B, C, and D of Figure 1. In Figure 1A, birds in the control group had a villus height lower than those fed with Gln. Figures 1B and C indicated that 0.2% and 0.4% Gln were able to promote the development of duodenum, but failed to match the performance of 0.8% Gln. Figure 1D demonstrated that 0.8% Gln clearly improved the growth of duodenum and led to the longest villus height and largest absorptive surface area. The results of villus width, villus height, crypt depth and muscular layer thickness were shown in Table 4. Compared with those in the control group, the birds in 0.8% Gln group had a higher villus height of duodenum (p<0.05), but there was no statistically significant difference in villus width, crypt depth, and muscular layer thickness (p>0.05).

The structure of oviduct was shown in Figure 2. Compared with the birds in the control group (Figure 2A), birds fed with different levels of Gln had a higher villus height and good oviductal integrity. 0.2% and 0.4% Gln in the diets were able to induce the recovery of oviduct (Figure 2B, C), but the effect of 0.8% Gln were more significant (Figure 2D).


In this study, lower levels of Gln in the diets of laying hens showed no difference on productive performance compared with the control group. Supplementation of 0.8% Gln in the diets of laying hens could improve egg production, egg mass, feed intake, and feed conversion efficiency, but it had little effect on egg quality. It was also observed that the dietary supplementation of 0.8% Gln could stimulate hormone secretion and induce better development of duodenum and oviduct in laying hens.


Previous studies showed that Gln supplementation had limited effects on metabolism, immune status, milk yield, DM intake (Doepel et al., 2006; Jafari et al., 2006), and glucose metabolism (Doepel et al., 2007) during the experimental period in dairy cows. Treatment of 1% dietary Gln did not improve the average daily gain (ADG) and intestinal morphology of calves (Drackley et al., 2006). In contrast to the results in cows and calves, the findings in pigs indicated that feeding 0.8-4% Gln in diet had beneficial effects in alleviating growth depression of E. coli K88+ challenged pigs (Yi et al., 2002; Yi et al., 2005b), enhancing body weight gain and feed efficiency of weaned piglets (Lackeyram et al., 2001; Wang et al., 2008). In poultry, supplementing the diet with 1% Gln improved (p<0.05) the weight gain and feed efficiency of broilers (Yi et al., 2001), and increased the ornithine decarboxylase (ODC) expression (Fischer da Silva et al., 2007b). Bartell et al. (2007) further indicated that the addition of 1% Gln to the diet of broiler chicks improved the weight gain, 4% Gln in diet or water depressed the growth performance. It was also observed in our study that supplementation of 0.8% Gln in diets of laying hens could promote the productive performance but had no effects on the egg quality. In our study, 1% Gln used for broilers and livestock was lowered to the level of 0.8% for laying hens, but a better performance was still found. The mechanism was further investigated to support our findings above.

Glutamine had significant effects on maintaining intestinal integrity and function (Liu et al., 2002; Wang et al., 2008), helping nutrient digestion and absorption. As an energy source for the maturation of the mucosa cells of the chicken (Maiorka et al., 2000), Gln could improve the intestinal villus height, intestinal relative weights, villus density, microvilli width, and surface area of the tip of the enterocytes in poults (Yi et al., 2001; Bartell et al., 2007; Fischer da Silva et al., 2007a; Murakami et al., 2007). In addition to promoting the intestinal integrity, Gln acted as an intestinal barrier against bacteria attacks to help the immune system to kill bacteria, and ensured host survival during critical situations. Glutamine was responsible for gut mass and maintenance of a bacteria barrier (Belmonte et al., 2007). During illness such as colitis, biliary obstruction, trauma and endotoxemia, Gln supplementation significantly modulated intestinal permeability and reduced bacterial translocation barrier functions (White et al., 2005; Vicario et al., 2007). It was found in our study that 0.8% Gln in the diets of laying hens could promote the development of duodenum and led to the longest villus height and largest absorptive surface area, thus increasing the absorptive surface of gastrointestinal mucosa and the utilization of dietary nutrients. Therefore, Gln could improve the productive performance of laying hens.

Glutamine could improve gonadal hormone levels in animal body for a better genital system growth. Glutamate (Glu) biosynthesis from Gln through binding to N-methyl-D-aspartate receptors (NMDAR) was an event contributing to the pubertal activation of luteinizing hormone-releasing hormone (LHRH) (Ottem et al., 2002; Roth et al., 2006) and pulsatile gonadotropin-releasing hormone (GnRH) secretion (Bourguignon et al., 1995). These data indicated that Gln was a prerequisite to the physiological mechanism of gonadal hormones. The oviduct of birds was the place where egg white and eggshell formed, and its development and functions could directly affect productive performance of layers. At the same time, the oviduct was the target organ of LH and FSH that could maintain higher secretion of the oviduct, thus increasing the quantity of egg laying, decreasing the feed conversion efficiency, and lengthening the crest-time of egg laying (Zuelke et al., 1993). LH in peripheral blood was directly correlated with the ovulation of layers. FSH could affect the growth and maturation of ovarian follicle, which had synergistic effects on ovulating with LH (Ooi et al., 2004). In this study, the morphology of oviduct, FSH and LH secretion was investigated, and it was found that 0.8% Gln in diets of laying hens kept a better morphology of oviduct, and enhanced FSH and LH secretion in blood. It was postulated that 0.8% Gln in diets could promote the productive performance through releasing higher levels of LH, FSH, keeping better development and secretion of oviduct.

[T.sub.3] and [T.sub.4] in peripheral blood of laying hens played their physiological functions in many ways such as facilitating the differentiation, growth and development of tissue, stimulating DNA transcription and mRNA formation, promoting the formation of protein and enzymes, increasing the utilization of carbohydrate, and enhancing the disintegration of amylon and fat (Ooi et al., 2004). After feeding with Gln for six weeks, the levels of [T.sub.3] and [T.sub.4] in the blood of hens were measured, and the results indicated that 0.8% Gln in diets could increase the concentration of [T.sub.3] and [T.sub.4], thus resulting in greater metabolisms and absorption of nutrients and enhanced performance of laying hens.

In conclusion, the results of this study showed that incorporating 0.8% Gln into a balanced layer diet could produce better development of the duodenum and recovery of the oviduct, maintain their integrity, promote hormone secretion, and lead to a better performance in laying hens.


This work was supported by the special funds of Shaoguan City Research Program of China (No. 313-140348).


Ardawi, M. S. M. and E. A. Newsholme. 1983. Glutamine metabolism in lymphocytes of the rat. Biochem. J. 212:835-842.

Bartell, S. M. and A. B. Batal. 2007. The effect of supplemental glutamine on growth performance, development of the gastrointestinal tract, and humoral immune response of broilers. Poult. Sci. 86:1940-1947.

Belmonte, L., M. Coeffier, F. Le Pessot, O. Miralles-Barrachina, M. Hiron, A. Leplingard, J. F. Lemeland, B. Hecketsweiler, M. Daveau, P. Ducrotte and P. Dechelotte. 2007. Effects of glutamine supplementation on gut barrier, glutathione content and acute phase response in malnourished rats during inflammatory shock. World. J. Gastroenterol. 13:2833-2840.

Bourguignon, J. P., A. Gerard, M. L. Alvarez Gonzalez, G. Purnelle and P. Franchimont. 1995. Endogenous glutamate involvement in pulsatile secretion of gonadotropin- releasing hormone: evidence from effect of glutamine and developmental changes. Endocrinol. 136: 911-916.

Boza, J. J., T. Marco and M. Denis. 2001. Effect of glutamine supplementation of the diet on tissue protein synthesis rate of glucocorticoid-treated rats. Nutrition 17:35-40.

de Oliveira, M. A., D. S. Lemos, S. O. Diniz, J. V. Coelho and V. N. Cardoso. 2006. Prevention of bacterial translocation using glutamine: a new strategy of investigation. Nutrition 22:419-424.

Doepel, L., M. Lessard, N. Gagnon, G. E. Lobley, J. F. Bernier, P. Dubreuil and H. Lapierre. 2006. Effect of Postruminal glutamine supplementation on immune response and milk production in dairy cows. J. Dairy Sci. 89:3107-3121.

Doepel, L., G. E. Lobley, J. F. Bernier, P. Dubreuil and H. Lapierre. 2007. Effect of glutamine supplementation on splanchnic metabolism in lactating dairy cows. J. Dairy Sci. 90:4325-4333.

Drackley, J. K., R. M. Blome, K. S. Bartlett and K. L. Bailey. 2006. Supplementation of 1% L-glutamine to milk replacer does not overcome the growth depression in calves caused by soy protein concentrate. J. Dairy Sci. 89:1688-1693.

Elsen, E. J., B. B. Bohren and H. E. Mckean. 1962. The Haugh unit as a measure of egg albumen quality. Poult. Sci. 41:1461-1468.

Fischer da Silva, A. V., A. Maiorka, S. A. Borges, E. Santin, I. C. Boleli and M. Macari. 2007a. Surface area of the tip of the enterocytes in small intestine mucosa of broilers submitted to early feed restriction and supplemented with glutamine. Int. J. Poult. Sci. 6:31-35.

Fischer da Silva, A. V., A. Borges, A. S. Maiorka, P. E. N. Givisiez, C. Rocha and M. Macari. 2007b. Ornithine decarboxylase expression in the small intestine of broilers submitted to feed restriction and glutamine supplementation. Rev. Bras. Cienc. Avic. l9:111-115.

Inoue, Y., J. P. Grant and P. J. Snyder. 1993. Effect of glutamine-supplemented intravenous nutrition on survival after Escherichia coli-induced peritonitis. JPEN J. Parenter. Enteral. Nutr. 17:41-46.

Iwashita, S., P. Williams, K. Jabbour, T. Ueda, H. Kobayashi, S. Baier and P. J. Flakoll. 2005. Impact of glutamine supplementation on glucose homeostasis during and after exercise. J. Appl. Physiol. 99:1858-1865.

Jafari, A., D. G. V. Emmanuel, R. J. Christopherson, J. R. Thompson, G. K. Murdoch, J. Woodward, C. J. Field and B. N. Ametaj. 2006. Parenteral administration of glutamine modulates acute phase response in postparturient dairy cows. J. Dairy Sci. 89:4660-4668.

Johnson, I. R., R. O. Ball, V. E. Baracos and C. J. Field. 2006. Glutamine supplementation influences immune development in the newly weaned piglet. Dev. Comp. Immunol. 30:1191-1202.

Johnson, A. T., Y. C. Kaufmann, S. Luo, V. Todorova and V. S. Klimberg. 2003. Effect of glutamine on glutathione, IGF-I, and TGF-beta 1. J. Surg. Res. 111:222-228.

Kaufmann, Y., J. Kornbluth, Z. Feng, M. Fahr, R. F. Schaefer and V. S. Klimberg. 2007. Effect of glutamine on gut glutathione fractional release in the implanted tumor model. Nutr. Cancer 59:199-206.

Kaufmann, Y., P. Spring and V. S. Klimberg. 2008. Oral glutamine prevents DMBA-induced mammary carcinogenesis via upregulation of glutathione production. Nutrition 24:462-469.

Kessel, A., E. Toubi, E. Pavlotzky, J. Mogilner, A. G. Coran, M. Lurie, R. Karry and I. Sukhotnik. 2008. Treatment with glutamine is associated with down-regulation of Toll-like receptor-4 and myeloid differentiation factor 88 expression and decrease in intestinal mucosal injury caused by lipopolysaccharide endotoxaemia in a rat. Clin. Exp. Immunol. 151:341-347.

Lackeyram, D., X. Yue and M. Z. Fan. 2001. Effects of dietary supplementation of crystalline L-glutamine on the gastrointestinal tract and whole bodygrowth in early-weaned piglets fed corn and soy bean meal based diets. J. Anim. Sci. 79:322.

Liu, T., P. Jian, Y. Z. Xiong, S. Q. Zhou and X. H. Cheng. 2002. Effects of dietary glutamine and glutamate supplementation on small intestinal structure, active absorption and DNA, RNA concentration in skeletal muscle tissue of weaned piglets during d 28 to 42 of age. Asian-Aust. J. Anim. Sci. 15:238-242.

Maiorka, A. A., V. F. Silva, E. Santin, S. A. Borges, I. C. Boleli and M. Macari. 2000. Influencia da suplementacao de glutamina sobre o desempenho e o desenvolvimento de vilos e criptas do intestino delgado de frangos. Arq. Bras. Med. Vet. Zoo. 52:487-490.

Mok, E., B. Constantin, F. Favreau, N. Neveux, C. Magaud, A. Delwail and R. Hankard. 2008. L-Glutamine administration reduces oxidized glutathione and MAP kinase signaling in dystrophic muscle of mdx mice. Pediatr. Res. 63:268-273.

Murakami, A. E., M. I. Sakamoto, M. R. M. Natali, L. M. G. Souza and J. R. G. Franco. 2007. Supplementation of glutamine and vitamin E on the morphometry of the intestinal mucosa in broiler chickens. Poult. Sci. 86:488-495.

Newsholme, P. 2001. Why is L-glutamine metabolism important to cells of the immune system in health post-immune, surgery, or infection? J. Nutr. 131:2515-2522.

NRC. 1994. Nutrient requirements of poultry. 9th. Revised ed., National Academy Press, Washington, DC.

Ooi, G. T., N. Tawadros and R. M. Escalona. 2004. Pituitary cell lines and their endocrine applications. Mol. Cell Endorcrinol. 228(1-2):1-21.

Ottem, E. N. and J. G. Godwin. 2002. Petersen. Glutamatergic signaling through the N-methyl-D-aspartate receptor directly activates medial subpopulations of luteinizing hormone-releasing hormone (LHRH) neurons, but does not appear to mediate the effects of estradiol on LHRH gene expression. Endocrinology 143:4837-4845.

Paganelli, C. V., A. Olszowka and A. Ar. 1974. The avian egg: surface area, volume, and density. Condor 76:319-325.

Roth, C. L., A. L. McCormack, A. Lomniczi, A. E. Mungenast and S. R. Ojeda. 2006. Quantitative proteomics identifies a change in glial glutamate metabolism at the time of female puberty. Mol. Cell. Endocrinol. 254-255:51-59.

Singleton, K. D. and P. E. Wischmeyer. 2008. Glutamine attenuates inflammation and NF-kappa B activation via Cullin1 deneddylation. Biochem. Biophys. Res. Commun. 373:445-449.

Smith, R. J. 1990. Glutamine metabolism and its physiologic importance. JPEN J. Parenter. Enteral. Nutr. 14:40S-44S.

Sukhotnik, I., K. Khateeb, J. G. Mogilner, H. Helou, M. Lurie, A. G. Coran and E. Shiloni. 2007. Dietary glutamine supplementation prevents mucosal injury and modulates intestinal epithelial restitution following ischemia-reperfusion injury in the rat. Dig. Dis. Sci. 52:1497-1504.

van der Hulst, R. R., M. F. von Meyenfeldt and P. B. Soeters. 1996. Glutamine: an essential amino acid for the gut. Nutrition 12:S78-81.

Vicario, M., C. Amat, M. Rivero, M. Moreto and C. Pelegri. 2007. Dietary glutamine affects mucosal functions in rats with mild DSS-induced colitis. J. Nutr. 137:1931-1937.

Wang, J., L. Chen, P. Li, X. Li, H. Zhou, F. Wang, D. Li, Y. Yin and G. Wu. 2008. Gene expression is altered in piglet small intestine by weaning and dietary glutamine supplementation. J. Nutr. 138:1025-1032.

White, J. S., M. Hoper, R. W. Parks, W. D. Clements and T. Diamond. 2005. Glutamine improves intestinal barrier function in experimental biliary obstruction. Eur. Surg. Res. 37:342-347.

Windmueller, H. G. and A. E. Spaeth. 1980. Respiratory fuels and nitrogen metabolism in vivo in small intestine of fed rats. J. Biol. Chem. 255:107-112.

Yeh, S. L., Y. N. Lai, H. F. Shang, M. T. Lin, W. C. Chiu and W. J. Chen. 2001. Effects of glutamine-supplemented total parenteral nutrition on cytokine production and T cell population in septic rats. JPEN J. Parenter. Enteral. Nutr. 25:269-274.

Yi, G. F., G. L. Allee, C. D. Knight and J. J. Dibner. 2005a. Impact of glutamine and Oasis hatchling supplement on growth performance, small intestinal morphology, and immune response of broilers vaccinated and challenged with Eimeria maxima. Poult. Sci. 84:283-293.

Yi, G. F., G. L. Allee, J. W. Frank, J. D. Spencer and K. J. Touchette. 2001. Impact of glutamine, menhaden fish meal, and spray-dried plasma on the growth and intestinal morphology of broilers. Poult. Sci. 80:201.

Yi, G. F., J. A. Carroll, G. L. Allee, A. M. Gaines, D. C. Kendall, J. L. Usry, Y. Toride and S. Izuru. 2005b. Effect of glutamine and spray-dried plasma on growth performance, small intestinal morphology, and immune responses of Escherichia coli [K88.sup.+]-challenged weaned pigs. J. Anim. Sci. 83:634-643.

Yi, G. F., G. L. Allee, Y. Toride, J. L. Usry and A. M. Gaines. 2002. Impact of glutamine, glutamate, and nucleotide on the growth performance and intestinal morphology of weaned piglets. J. Anim. Sci. 80:198.

Zuelke, K. A. and B. G. Brackett. 1993. Increased glutamine metabolism in bovine cumulus cell-enclosed and denuded oocytes after in vitro maturation with luteinizing hormone. Biol. Reprod. 48:815-820.

Dong Xiao-Ying, Yang Chu-Fen (1), Tang Sheng-Qiu *, Jiang Qing-Yan (2) and Zou Xiao-Ting (3)

Department of Agricultural Science, Shaoguan University, Shaoguan, 512005, China

* Corresponding Author: Tang Sheng-Qiu. Tel: +86-751-8620272, E-mail:

(1) Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China.

(2) College of Animal Science, South China Agricultural University, Guangzhou, 510642, China.

(3) College of Animal Science, Zhejiang University, Hangzhou, 310029, China.

Received December 6, 2009; Accepted February 23, 2010
Table 1. Compositions and nutrient levels of the experimental
basal diets %

                                   Ingredient compositions
Items                                       % DM

Corn                                        62.50
Soybean meal                                24.10
Fish meal                                    1.00
Soybean oil                                  1.25
Calcium phosphate                            1.45
Limestone meal                               7.87
Lysine (78%)                                 0.28
DL-methionine (98%)                          0.15
NaCl                                         0.32
Choline chloride (75%)                       0.08
Mineral and vitamin premix (1)               1.00
Analyzed chemical composition
  Crude protein (%)                         18.29
  Calcium (%)                                3.62
  Available phosphorus (%)                   0.46
  Lysine (%)                                 0.81
  Methionine (%)                             0.42
  Methionine+cystine (%)                     0.67
  ME (2) (MJ/kg)                            11.68

(1) Provided per kilogram of diet: vitamin A, 11,000 RJ; vitamin E,
20 RJ; vitamin [K.sub.3], 2.0 mg; thiamin, 2.0 mg; riboflavin, 5.0 mg;
niacin, 25.0 mg; pantothenic acid, 10.0 mg; vitamin [B.sub.6], 3.5 mg;
vitamin [B.sub.12], 0.015 mg; folic acid, 1.0 mg; biotin, 0.05 mg;
choline, 1,000.0 mg; vitamin C, 100.0 mg; Mn, 80.0 mg; Zn, 60.0 mg;
Fe, 50.0 mg; Cu, 7.5 mg; I, 1.2 mg; Co, 0.8 mg; and Se, 0.1 mg.

(2) The data is calculated.

Table 2. Effects of dietary glutamine on productive performance
and egg quality in laying hens (n = 10)

Items                                     0 (control)    0.2% Gln

Egg production (%)                         83.81 (c)     84.11 (c)
Egg mass1 (g/hen per d)                    47.95 (b)     48.17 (b)
Feed intake (g/hen per d)                 101.11 (b)    103.25 (b)
Feed conversion efficiency (2) (g/g)        2.15 (b)      2.13 (b)
Egg weight (g)                             57.20         57.26
Yolk weight (g)                            14.56         14.59
Shell weight (g)                            5.50          5.46
Egg shape index (3)                         1.32          1.32
Shell density (mg/[cm.sup.2])              96.77         97.05
Shell thickness (mm)                        0.34          0.34
Shell breaking strength (kg/[cm.sup.2])     3.57          3.59
Yolk index (4)                              0.43          0.43
Yolk color                                  8.37          8.36
Haugh unit                                 83.61         83.81

Items                                      0.4% Gln      0.8% Gln

Egg production (%)                         84.97 (b)     87.01 (a)
Egg mass1 (g/hen per d)                    48.76 (b)     51.31 (a)
Feed intake (g/hen per d)                 103.48 (b)    106.85 (a)
Feed conversion efficiency (2) (g/g)        2.14 (b)      2.06 (a)
Egg weight (g)                             57.38         58.97
Yolk weight (g)                            14.65         14.78
Shell weight (g)                            5.53          5.66
Egg shape index (3)                         1.34          1.33
Shell density (mg/[cm.sup.2])              96.87         96.92
Shell thickness (mm)                        0.34          0.33
Shell breaking strength (kg/[cm.sup.2])     3.60          3.60
Yolk index (4)                              0.42          0.43
Yolk color                                  8.50          8.49
Haugh unit                                 83.83         83.64

Items                                         SEM

Egg production (%)                           0.21
Egg mass1 (g/hen per d)                      0.48
Feed intake (g/hen per d)                    0.97
Feed conversion efficiency (2) (g/g)         0.02
Egg weight (g)                               0.49
Yolk weight (g)                              0.34
Shell weight (g)                             0.12
Egg shape index (3)                          0.01
Shell density (mg/[cm.sup.2])                1.56
Shell thickness (mm)                         0.01
Shell breaking strength (kg/[cm.sup.2])      0.11
Yolk index (4)                               0.14
Yolk color                                   0.08
Haugh unit                                   1.26

(a,b,c) Different letters for the same line denote significant
differences (p < 0.05).

(1) Egg mass = (egg production x egg weight)/100. (2) Feed conversion
efficiency = Feed intake/egg mass (g/g). (3) Egg shape index = Egg
height/egg width. (4) Yolk index = Yolk height/yolk width.

Table 3. Effect of dietary glutamine on hormone levels of serum in
laying hens (n = 10)

Items                                        0 (control)    0.2% Gln

Triiodothyronine (ng/ml)                       2.08 (c)     2.11 (c)
Tetraiodothyronine (ng/ml)                    13.04 (b)    13.12 (b)
Luteinizing hormone ([micro]g/ml)              2.40 (c)     2.46 (bc)
Follicle stimulating hormone ([micro]g/ml)     2.17 (c)     2.24 (c)

Items                                         0.4% Gln      0.8% Gln

Triiodothyronine (ng/ml)                       2.34 (b)     2.76 (a)
Tetraiodothyronine (ng/ml)                    13.54 (a)    13.67 (a)
Luteinizing hormone ([micro]g/ml)              2.52 (b)     2.66 (a)
Follicle stimulating hormone ([micro]g/ml)     2.46 (b)     2.75 (a)

Items                                            SEM

Triiodothyronine (ng/ml)                        0.03
Tetraiodothyronine (ng/ml)                      0.18
Luteinizing hormone ([micro]g/ml)               0.02
Follicle stimulating hormone ([micro]g/ml)      0.01

(a,b,c) Different letters for the same line denote significant
differences (p < 0.05).

Table 4. Effects of glutamine on duodenum morphology of laying
hens (n = 3) (1)

Items                                       0 (Control)

Villus width ([micro]m)               131.15 [+ or -] 0.12
Villus height ([micro]m)              876.35 [+ or -] 1.34 (c)
Crypt depth ([micro]m)                126.51 [+ or -] 0.24
Muscular layer thickness ([micro]m)   145.25 [+ or -] 3.62

Items                                         0.2% Gln

Villus width ([micro]m)               131.32 [+ or -] 0.24
Villus height ([micro]m)              884.56 [+ or -] 0.25 (c)
Crypt depth ([micro]m)                126.41 [+ or -] 2.89
Muscular layer thickness ([micro]m)   147.25 [+ or -] 2.38

Items                                         0.4% Gln

Villus width ([micro]m)               131.56 [+ or -] 0.36
Villus height ([micro]m)              927.34 [+ or -] 0.53 (b)
Crypt depth ([micro]m)                125.12 [+ or -] 1.45
Muscular layer thickness ([micro]m)   146.25 [+ or -] 0.56

Items                                         0.8% Gln           SEM

Villus width ([micro]m)               132.03 [+ or -] 0.15       0.47
Villus height ([micro]m)              945.42 [+ or -] 2.14 (a)   2.65
Crypt depth ([micro]m)                125.25 [+ or -] 2.68       1.76
Muscular layer thickness ([micro]m)   148.25 [+ or -] 2.32       1.68

(a,b,c) Different letters for the same line denote significant
differences (p < 0.05).

(1) The height and width of 30 villi, the depth of 30 crypts
and the thickness of 30 muscular layers were measured from
each replicate.
COPYRIGHT 2010 Asian - Australasian Association of Animal Production Societies
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2010 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Xiao-Ying, Dong; Chu-Fen, Yang; Sheng-Qiu, Tang; Qing-Yan, Jiang; Xiao-Ting, Zou
Publication:Asian - Australasian Journal of Animal Sciences
Article Type:Report
Geographic Code:9CHIN
Date:Jul 15, 2010
Previous Article:Effects of dietary Fe-soy proteinate and MgO on egg production and quality of eggshell in laying hens.
Next Article:Effects of antibiotics, zinc oxide or a rare earth mineral-yeast product on performance, nutrient digestibility and serum parameters in weanling pigs.

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters