Partial ablation of uropygial gland effects on growth hormone concentration and digestive system histometrical aspect of akar putra chicken

Partial ablation of uropygial gland effects on growth hormone concentration and digestive system histometrical aspect of akar putra chicken Hasan S. A. Jawad,∗,†,1 I. H. Lokman,∗ A. B. Z. Zuki,∗ and A. B. Kassim‡ ∗

Dept. of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, University of Putra Malaysia, Malaysia; † Dept. of Veterinary Anatomy, Histology, and Embryology, Faculty of Veterinary Medicine, University of Baghdad, Iraq; and ‡ Dept. of Animal Sciences, Faculty of Agriculture, University of Putra Malaysia, Malaysia

Key words: growth hormone, uropygial gland, Akar putra chicken 2016 Poultry Science 00:1–8 http://dx.doi.org/10.3382/ps/pev444

INTRODUCTION

hormones, including somatomedins, epidermal growth hormone, sex steroids, and vitamin D metabolites, are also involved in the control of growth. Considerable study will be required for the elucidation of the exact roles of the various hormones in avian growth (Scanes et al., 1984; Zheng et al., 2007). Pituitary GH production and secretion are regulated by the hypothalamic hormones’ somatostatin and GH releasing hormone (GHRH). GH has a direct effect on muscle, bone, fat, lipolysis, and reproduction. GH also has an indirect effect on those organs by stimulating the liver to secrete insulin-like growth factor IGF-I. (Wang et al., 2006). The avian digestive tract consists of an alimentary tract of the head (mouth cavity, including the beak, tongue, and pharynx), and the alimentary tract of the trunk comprising the esophagus (upper and lower parts), crop, proventriculus, gizzard, small intestine (duodenum, jejunum, and ileum), and the large intestine, which in birds has a double cecum, a short colon, and multifunctional cloaca (Bellairs, R., and Osmond, M. 2005). The wall of most all GIT parts histologically consists of 4 layers: mucosa, submucosa, muscularis,

Akar Putra is a Malaysian chicken, created in the University of Putra Malaysia by Assoc. Prof. A. B. Kassim (Jawad et al., 2015). The uropygial gland (UG) is the only subcutaneous gland in body, lying on the base of the tail, dorsally between the fourth caudal vertebrae and the pygostyl. The function of the gland is still a subject of controversy; however, there are many accepted functions of the gland’s secretions, such as conferring water-repellent properties on the feather coat and maintaining the suppleness of it (Vincze et al. 2013). The hormonal control of growth in poultry and other species is complex. The available evidence supports the concept that growth hormone (GH) and the thyroid hormones are the principal hormones responsible for the attainment of normal growth in domestic fowl. Other  C 2016 Poultry Science Association Inc. Received September 5, 2015. Accepted November 10, 2015. 1 Corresponding author: [email protected] The scientific section for the paper is Education and Production.

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were randomly isolated and euthanized to perform the necropsy. Digestive system organs’ cross sections were measured by a computerized image analyzer after being stained with haematoxylin and eosin. In comparison with the control group, surgical removal of the uropygial gland, especially at wk 3, had a greater (P < 0.01) effect on the total duodenum, jejunum, and ilium wall thickness. In addition, effects (P < 0.05) were observed on the wall thickness of males’ cecum and colon. Moreover, the wall layers of the esophagus, proventriculus, gizzard, and rectum were not affected by the treatment. However, removing the uropygial gland showed significant impact (P < 0.05) in males’ growth hormone concentration level at wk 7 and (P < 0.01) effects at wk 12 in both sexes. This study provides a novel and economic alternative to enhance the body performance of poultry in general and Akar Putra chickens particularly.

ABSTRACT Partial ablation of the uropygial gland is being used in the poultry industry as a new way to enhance body performance of chickens. However, limited data are available estimating the efficacy of partial uropygialectomy (PU) to improve body organ activity. The present study evaluated the effect of partial ablation of the uropygial gland on the serum growth hormone concentration level and digestive system histology of 120 Akar Putra chickens in 5 trials with 3 replicates per trial. The experimental treatments consisted of a control treatment T1; partial ablation of the uropygial gland was applied in the T2, T3, T4, and T5 treatments at 3, 4, 5, and 6 wk of age, respectively. Feed and water were provided ad libitum. All treatment groups were provided the same diet. Venous blood samples were collected on wk 7, 10, and 12 to assay the levels of growth hormone concentration. On the last d of the experiment, 4 birds per replicate

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MATERIALS AND METHODS Animals and Housing This research was conducted on the poultry farm of Veterinary Medicine Faculty in the University of Putra Malaysia (UPM) from December 15, 2014, to March 15, 2015. Furthermore, it was approved by the Institutional Animal Care and Use Committee (IACUC) certificate number R070. This study consisted of 120-dayold local Malaysian chicks (Akar Putra strain). They were randomly assigned to 5 treatment groups by 24 (12 male and 12 female) per treatment, and each treatment consisted of 3 replicates of 8 (4 males and 4 females) birds per replicate. The birds were housed in wire cages with 8 birds (4 males and 4 females) per pen (5”x 4”x1.5”). Chickens were fed the same diets and feed was offered ad libitum (1 to 13 d: starter; 14 d slaughter: finisher) with water provided continuously. Furthermore, constant lighting and continuous ventilation were provided. All the birds were kept under uniform management conditions throughout the experimental period of 12 wk.

Partial Uropygialectomy (PU) PU was applied with T2, T3, T4, and T5 treatments at 3, 4, 5, and 6 wk of age, respectively. It was conducted based upon the procedure reported by (Jawad et al., 2015).

Growth Hormone Assay Serum from 2 males and 2 females per replicate was assayed to measure the concentration of GH. Because

the secretion of GH in the chickens was pulsatile, and the GH level was not constant in a day-night period (Zheng et al., 2007), we collected 3 mL blood samples from a wing vein in the morning and within a short period (0800 to 0900 h) at 7, 10, and 12 wk. The serum was separated by centrifugation at 4,000 rpm for 15 min and then stored at −20◦ C for the assay of GH. All tips and tubes were sterilized by autoclave at 121o C and 15 bar for 15 min. A chicken GH elisa kit (CSB-E09866CH), supplied by (CUSABIO Company, Serdang, Selangor, Malaysia) was used, following its procedure. This assay employs the competitive inhibition enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with an antibody specific to GH. Standards or samples are added to the appropriate microtiter plate wells with biotin-conjugated GH. A competitive inhibition reaction is launched between GH (standards or samples) and biotin-conjugated GH with the pre-coated antibody specific for GH. The more amount of GH in samples, the less antibody bound by biotin-conjugated GH. After washing, avidin conjugated horseradish peroxidase (HRP) is added to the wells. Substrate solution is then added to the wells, and the color develops in an opposite manner to the amount of GH in the sample. The color development is stopped, and the intensity of the color is measured.

GIT Histometrical Assay For enteric morphometric analysis, 4 birds (2 males, 2 females) per replicate on the last d of the experiment were euthanized by cutaneous ulnar vein injection of pentobarbito sodum (80 mg/kg) (Mitchell and Smith, 1991), and digestive system organs were collected. A 1-cm segment from the midpoint of the esophagus, proventriculus, gizzard, duodenum, jejunum, ileum, cecum, colon, and rectum were removed and fixed in 10% buffered formalin for 72 h. Each segment was then embedded in paraffin, and a 2μm section of each sample was placed on a glass slide and stained with hematoxylin and eosin for examination with a light microscope (Sakamoto et al., 2000). The parameters evaluated were mucosa, submucosa, mascularis, and serosa layers thickness. Furthermore, the measurements of intestinal mucosal parameters (villi length, crypt depth, and mascularis mucosa) and the villi surface area also were evaluated. Morphological parameters were measured by a computerized image analyzer (Leica DM LB2, Germany). Ten measurements were taken per bird per parameter. Villi length was measured from the top of the villi to the villi-crypt transition area. The villi surface area was calculated by following the villi height from base to base. Crypt depth was measured from the base upwards to the region of transition between the crypt and villi (Aptekmann et al., 2001). Variation ration was counted based on the formula reported by (Jawad et al., 2015).

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and serosa. The mucosa of the small intestine forms villi that projects into the lumen and greatly increases the overall absorption surface area of the organ. The epithelium surface of the villi is a small columnar epithelium with numerous goblet cells. Intestinal absorptive cells have extensive microvilli on their apical surface. Goblet cells are scattered between the absorptive cells and produce the mucous (Ann, 2004). Intestinal glands (crypts of lieberkuhn) extend from the base of the villi into the underlying lamina properia (Aughey and Frye, 2001). The current study was aimed to elucidate the effect of partial removal of the uropygial gland on the serum GH concentration level and histometrical parameters of Akar Putra chickens’ digestive system. In a previous report, it was hypothesized that the mechanism resulted in an improvement in the production performance of Akar Putra chickens after removal of the uropygial gland (Jawad et al., 2015) due to an increase in the level of GH and enhancement of the histometrical parameters of the digestive system organs.

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PU EFFECTS ON GH AND DIGESTIVE SYSTEM HISTOLOGY Table 1. Effect of PU operation on serum growth hormone concentration (pg/ml) at three periods. Treatments Week

Sex

T1

7

♂ ♀ ♂ ♀ ♂ ♀

± ± ± ± ± ±

10 12

3976.29 3856.145 3635.103 3895.603 3386.01 3537.007

T2 b

35.986 23.5.799 89.671 85.311 111.728b 225.441b

4356.695 4135.135 3996.397 4078.213 4043.373 4199.273

± ± ± ± ± ±

T3 a,∗

42.427 42.427 53.868 130.256 400.523a 84.232a

4160.365 4051.495 4009.633 3916.14 3817.87 3588.193

± ± ± ± ± ±

T4 a,b

24.061 74.256 44.398 56.259 195.683a,b 46.304b

4267.305 4186.07 3940.27 4191.893 3799.197 4231.143

± ± ± ± ± ±

T5 a

55.411 6.611 138.232 95.731 39.891a,b 25.334a,∗∗

4003.88 4219.045 3986.687 4209.963 3930.523 4307.29

± ± ± ± ± ±

129.609b 54.776 97.436 27.162 119.207a 24.593a,∗

Mean values with common superscript in male rows differ significantly (P < 0.05). Mean values with (common superscript in female rows differ significantly (P < 0.01). ∗ Mean values with common superscript means significant difference (P < 0.05) between males and females. ∗∗ Mean values with common superscript means significant difference (P < 0.01) between males and females. ♂: male; ♀: female. a,b a,b

Treatments GIT part

Sex

Parameter

E

♂

M SM MA S TWT M SM MA S TWT M SM MA S TWT M SM MA S TWT K M SM MA S TWT K M SM MA S TWT

♀

P

♂

♀

G

♂

♀

T1 63.719 2.041 11.34 2.131 79.231 22.947 1.981 20.454 2.022 47.404 45.832 165.703 14.62 2.034 228.189 44.832 164.37 14.54 2.214 225.956 16.108 17.734 12.166 213.6 1.88 261.488 16.108 17.334 11.366 212.2 1.8 258.808

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T2 3.384 0.171 0.293 0.169 3.393 1.382 0.243 0.763 0.21 1.716 0.82 3.044 1.553 0.199 4.596 1.523 2.87 1.589 0.373 4.827 0.569 0.608 0.907 3.868 0.066 3.567 0.569 0.468 0.736 3.813 0.054 3.753

64.719 2.141 11.66 2.331 80.851 23.547 2.181 20.854 2.122 48.704 46.232 166.037 15.02 2.19 229.479 45.632 166.037 14.83 2.234 228.733 16.268 17.594 12.366 214.8 1.94 262.968 16.162 17.534 13.166 213.6 1.88 262.342

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T3 2.871 0.125 0.273 0.184 2.77 1.552 0.317 1 0.227 2.072 0.758 3.113 1.427 0.265 4.354 0.917 3.113 1.474 0.37 4.556 0.518 0.666 0.976 3.072 0.121 2.483 0.607 0.504 1.508 3.868 0.066 3.963

64.019 2.071 11.54 2.231 79.861 23.087 2.021 20.554 2.052 47.714 46.032 165.77 14.82 2.168 228.79 45.032 164.453 14.6 2.238 226.323 16.108 17.734 12.566 214.4 1.96 262.768 16.202 17.496 13.026 212.6 1.8 261.124

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T4 3.206 0.152 0.265 0.146 3.181 1.414 0.247 0.81 0.21 1.787 0.764 3.057 1.478 0.25 4,42 1.352 2.875 1.562 0.37 4.726 0.569 0.608 1.079 3.311 0.14 2.947 0.629 0.491 1.498 3.776 0.1 3.971

63.819 2.081 11.49 2.131 79.521 22.947 2.011 20.654 2.072 47.684 46.144 166.07 14.732 2.108 229.054 44.944 165.037 14.492 2.254 226.727 16.108 17.734 12.366 214.2 1.98 262.388 16.222 17.436 13.314 212.4 1.84 261.212

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T5 3.323 0.146 0.277 0.169 3.331 1.418 0.245 0.867 0.213 1.944 0.754 3.12 1.508 0.217 4.524 1.426 2.935 1.612 0.369 4.773 0.569 0.608 0.976 3.441 0.159 3.075 0.675 0.476 1.466 3.789 0.075 3.915

63.919 2.131 11.57 2.241 79.861 23.347 2.081 20.754 2.092 48.274 46.164 166.087 14.892 2.39 229.533 45.512 165.703 14.64 2.258 228.113 16.108 17.734 12.564 214 2 262.406 16.196 17.734 13.566 213.2 1.78 262.476

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

3.264 0.127 0.26 0.147 3.218 1.486 0.264 0.931 0.217 1.981 0.754 3.124 1.456 0.427 4.576 0.991 3.044 1.544 0.369 4.655 0.569 0.608 1.078 3.578 0.179 3.255 0.562 0.608 1.426 3.8 0.116 3.389

E: esophagus; P: proventriculus; G: gizzard; M: mucosa; SM: submucosa; MA: muscularis; S: serosa; K: Keratinoid; TWT: total wall thickness (K+M+SM+MA+S); ♂: male; ♀: female.

Statistical Analysis This research used one way complete random sampling (Steel and Torrie, 1980). Data results were analyzed by one way analysis of variance (ANOVA). If the treatment significantly affected the chicken, LSD and Duncan (1955) Multiple Range were applied (DRMT) (Genstat, 2003). Differences among treatments were considered significant at P < 0.01 and P < 0.05.

RESULTS Serum GH Concentration The effect of partial ablation of UG on GH concentration in the serum of Akar Putra chickens is presented in Table 1. Removing the gland in males at wk 3, 4, and 5 resulted in higher GH concentration at 7 wk of age (P < 0.05), and their ration variations from

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Table 2. Effect of PU operation on the histometrical parameters of upper part of digestive system at 12 wk of age.

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Table 3. Effect of PU operation on the histometrical parameters of males’ small intestinal parts at 12 wk of age. Treatments GIT part D

J

T1

VL AAV DL MM TMT SM MA S TWT VL AAV DL MM TMT SM MA S TWT VL AAV DL MM TMT SM MA S TWT

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

61.026 266.536 6.345 1.554 68.925 0.857 6.786 1.982 78.55 43.318 95.5 8.922 1.62 53.86 1.194 9.614 1.53 66.198 35.52 65.528 6.852 1.534 43.906 1.11 8.962 1.58 55.558

T2 d

3.728 11.473c 0.353c 0.109a–c 3.499d 0.048b 0.446b 0.121b 3.266d 1.964c 3.97c 0.416a,b 0.169a,b 2.291c 0.193b 0.568a 0.085 2.18c 3.003c 11.035c 0.338c 0.1 2.849c 0.051b 0.319b 0.226 2.684c

107.017 383.608 10.264 1.64 118.921 1.48 7.881 1.853 130.135 65.21 136.652 10.244 1.868 77.322 1.9 6.96 1.536 87.718 51.874 88.64 10.534 1.648 64.056 1.168 10.234 1.854 77.312

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T3 a

2.168 8.443a 0.393b 0.16a,b 2.3a 0.158a 0.314a,b 0.144b 2.507a 0.592a 1.778a 0.311a 0.127a 0.795a 0.186a 0.491b 0.167 0.84a 6.851b 3.645b 0.596a 0.139 6.315b 0.075b 0.12a 0.108 6.295a,b

92.944 361.868 12.151 1.851 106.946 1.403 6.966 2.07 117.385 54.8 107.448 8.274 1.228 64.302 0.852 6.928 1.544 73.626 47.596 97.936 8.902 1.73 58.228 2.074 8.79 1.896 70.988

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T4 b

2.304 11.822a,b 0.231a 0.102a 2.403b 0.113a 0.341b 0.176b 2.484b 3.222b 1.615b 0.533b 0.148c 3.429b 0.086b 0.284b 0.146 3.669b 1.066b,c 1.068b 0.727a,b 0.105 1.453b 0.155a 0.2b 0.105 1.669b

75.1 339.148 10.501 1.477 87.078 1.409 8.688 2.792 99.967 48.636 102.98 10.07 1.426 60.132 1.074 7.02 1.318 69.544 49.44 99.524 8.324 1.564 59.328 1.21 7.712 1.538 69.788

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T5 c

5.3 11.448b 0.503b 0.064b,c 5.304c 0.089a 0.315a 0.162a 5.174c 2.093c 5.734b,c 1.013a 0.033b,c 1.183b 0.088b 0.138b 0.101 1.144b,c 0.984b 4.075b 0.652b,c 0.1 1.307b 0.082b 0.293c 0.154 1.424b

107.513 385.608 10.601 1.295 119.409 0.994 8.426 2.327 131.156 69.788 137.7 7.594 1.22 78.602 1.008 9.948 1.79 91.348 64.73 135.836 10.496 1.948 77.174 1.228 7.886 1.478 87.766

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

5.779a 7.377a 0.294b 0.091c 5.84a 0.079b 0.668a 0.167b 5.802a 1.096a 3.896a 0.157b 0.041c 1.185a 0.055b 0.458a 0.073 1.575a 5.158a 5.773a 0.343a 0.175 5.311a 0.089b 0.181c 0.133 5.216a

Mean values with common superscript in rows differ significantly (P < 0.01). MM of duodenum and DL of jejunum means values with (a, b, c) common superscript in rows differ significantly (P < 0.05). D: duodenum; J: jejunum; I: ileum; Vl: villi length; AAV: absorptive area of villi; DL: depth of Crypts of lieberkuhn; MM: muscularis mucosa; TMT: total mucosa thickness (VL+DL+MM); SM: submucosa; MA: muscularis; S: serosa; TWT: total wall thickness (TMT+SM+MA+S). a-d

the control group were 9.6, 7.3, and 4.6%, respectively. Removal of the gland in females did not have effect on GH concentration at 7 wk of age. Assaying GH concentration at 10 wk of age did not show a significant different (P > 0.05) for either sex. Contrarily, its level at 12 wk of age revealed that all PU treatments had dependent superiority (P < 0.05) over the control treatment in males; however, there was no significant difference among transactions 3, 4, and the control group. The highest variation ratio from the control group was observed in T2 (25.3%) followed by T5 (16.1%), T3 (12.8%), and T4 (12.2%). Moreover, highly significant (P < 0.01) superiority in females at wk 12 was reported for T5 (21.8%), T4 (19.6%), and T2 (18.7%). Interestingly, applying the PU operation at wk 3 caused a more significant difference (P < 0.05) for males than females in GH concentration at 7 wk of age, while at wk 12, the GH concentration was higher in females than males in T4 (P < 0.01) and T5 (P < 0.05).

Histometrical Parameters of the Digestive System The effect of the PU operation on the histometric parameters of the upper part of the digestive system at 12 wk of age is presented in Table 2. It clearly refers to

the absence of statistical differences among the treatments in the total wall thickness of the upper part of the digestive tract, which includes the esophagus, proventriculus, and gizzard. Whereas, high significant differences (P < 0.01) were diagnosed in the layer thickness of the small intestinal wall in males and females with the PU transaction and in the control group (Tables 3 and 4). The highest wall thickness of the duodenum, jejunum, and ileum in male chickens were recorded in T2 (65.7; 32.5; and 39.2%) and T5 (67; 38; and 58%), resulting mainly from the high significant difference (P < 0.01) in the length of the villi (75.4; 50.5; and 46%) for T2 and (76.2; 61.1; and 82.2%) for T5. These results did not differ much in terms of female chickens; the superiorities (P < 0.01) in the wall thickness of each duodenum and ileum were also for T2 (46.9 and 67.8%) and T5 (26.7 and 78.6%), caused by the noticeable difference (P < 0.01) in the mucous layer thickness for T2 (42.9 and 77.2%) and T5 (27.7 and 81.2%). In addition, Tables 5 and 6 revealed that statistical impacts (P < 0.05) were observed only in the wall thickness of males’ cecum and colon for T2 (21 and 9.7%), T3 (6.6 and 9.7%), T4 (4.8 and 3%), and T5 (21.3 and 8.7%). However, no significant influence existed (P > 0.05) among T3, T4, and the control group in the total cecum wall thickness, and between T4 and the control group in the total colon wall thickness.

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I

Parameter

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PU EFFECTS ON GH AND DIGESTIVE SYSTEM HISTOLOGY Table 4. Effect of PU operation on the histometrical parameters of females’ small intestinal parts at 12 wk of age. Treatments GIT part D

J

T1

VL AAV DL MM TMT SM MA S TWT VL AAV DL MM TMT SM MA S TWT VL AAV DL MM TMT SM MA S TWT

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

54.024 136.906 8.952 1.423 64.399 1.311 5.694 1.465 72.869 58.378 119.412 8.604 1.072 68.054 1.364 6.15 1.628 77.196 28.784 62.46 6.476 1.384 36.644 1.144 7.368 1.522 46.678

T2 b

3.101 6.602 0.271c 0.089b 3.082c 0.091 0.257c 0.128b 2.848c 1.959 5.069 0.765a,b 0.083 2.607 0.082 0.242d 0.156 2.814 1.949b 4.359b 0.468d 0.119 2.104c 0.092b 0.241d 0.094b 2.366b

71.236 151.132 18.614 2.146 91.996 1.452 11.992 1.57 107.01 61.534 130.736 6.86 1.406 69.8 1.032 9.978 1.164 81.974 52.442 104.76 11.26 1.232 64.934 1.1 11.02 1.256 78.31

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T3 a

1.18 4.524 0.471a 0.055a 1.559a 0.1 0.478a 0.054b 1.876a 4.218 5.426 0.259b 0.088 4.174 0.111 0.498a 0.085 4.263 1.554a 6.822a 0.696a,b 0.073 2.178a 0.027b 0.352b 0.049b 2.218a

51.256 135.906 7.498 1.478 60.232 1.423 8.438 1.47 71.563 58.378 119.412 9.83 1.268 69.476 1.098 7.844 1.496 79.914 31.744 67.816 10.204 1.422 43.37 0.972 6.742 1.396 52.48

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T4 b

2.612 6.231 0.339d 0.106b 2.519c 0.069 0.434b 0.125b 2.677c 3.752 9.702 0.76a 0.137 3.467 0.124 0.338c 0.105 3.265 1.632b 3.46b 0.649b,c 0.097 2.16b 0.021b 0.306d 0.089b 2.47b

68.744 149.394 10.281 1.587 80.612 1.317 8.903 2.008 92.84 60.178 123.412 8.394 1.028 69.6 0.982 8.288 1.42 80.29 28.512 61.048 8.19 1.544 38.246 1.478 9.232 1.22 50.176

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T5 a

1.687 7.763 0.375b 0.104b 1.592b 0.121 0.345b 0.101a 1.706b 3.557 8.815 0.748a,b 0.065 3.246 0.089 0.172b,c 0.057 3.126 0.649b 1.654b 0.418cd 0.08 0.882b,c 0.104a 0.107c 0.089b 0.925b

69.827 149.394 10.975 1.462 82.264 1.306 6.666 2.072 92.308 59.242 126.228 9.774 1.232 70.248 0.976 8.852 1.496 81.572 52.544 110.628 12.442 1.424 66.41 1.62 13.354 1.98 83.364

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

1.83a 2.783 0.497b 0.053b 2.056b 0.127 0.438c 0.06a 1.972b 0.876 1.971 0.162a 0.124 0.916 0.081 0.199b 0.144 0.875 1.786a 5.264a 1.032a 0.125 1.797a 0.148a 0.512a 0.201a 1.478a

Mean values with common superscript in rows differ significantly (P < 0.01). DL of jejunum mean values with common superscript in row differ significantly (P < 0.05). D: duodenum; J: jejunum; I: ileum; Vl: villi length; AAV: absorptive area of villi; DL: depth of Crypts of lieberkuhn; MM: muscularis mucosa; TMT: total mucosa thickness (VL+DL+MM); SM: submucosa; MA: muscularis; S: serosa; TWT: total wall thickness (TMT+SM+MA+S). a-d a-d

DISCUSSION The results showed that the partial ablation of the UG did not have any serious consequence for the survival of Akar Putra chickens and no mortality happened during the trial period. This agrees with (Jacob, 1976; Chen et al., 2003) who, in considering the physiological role of the UG, noted that it appears the gland is not necessarily present in all groups of birds. This fact, observed in a number of species, together with the lack of a clear-cut ecological correspondence, suggests that, when present, the function of the gland may be diverse but not essential. In this regard, it is interesting that the extirpation of the gland was not dangerous for the survival of goslings, hens, or passerine birds. Furthermore, Montalti and Saliban (2000) mentioned that the oil of the UG is not important to the birds who do not have it, while, Goodwin (1983) reported that the UG in some birds is non-active. Later, Moyer et al., (2003a,b) explained that birds that do not have a UG use duster baths to clean their feathers.

Effect of the PU Operation on GH Concentration: Based on the results, this study suggested that the UG wastes precious substances from the body of the

bird. These substances are the essential fatty acids, especially Aarchidonic acid. Normally, Archidonic acid is analyzed in the body to the prostaglandins, thromboxanes, lipoxines and leukotrienes (Davidson and Abramowitz, 2002). Prostaglandins are responsible for stimulating the anterior pituitary gland to produce and release GH (Girouard and Savard, 1998). On the other hand, removing the UG makes the body use the gland’s oil to produce important materials like GH. Through the GH test results, it was noted that the concentration of GH in the blood decreased with the age.. Scientists reported that in all bird species studied, plasma GH concentration was high during the rapid growth period. Then, plasma GH concentrations declined during the slow growth period to reach low concentrations in adult birds (Vasilatos and Scanes, 1991; Vasilatos-Younken et al., 1999). In this experiment, GH concentration was high at 7 wk of age and decreased gradually at wk 10 and 12, confirming the above-mentioned result . On the other hand, this study contends that animal metabolism is controlled by a variety of hormones that form a complex system that directly affects growth. Among hormones, GH has been reported to be involved in chicken growth control (Parmer et al., 1987; Harden and Oscar, 1993). However, it should be emphasized that the final growth expression is the result of interactions among nutritional, environmental, and genetic factors,

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I

Parameter

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JAWAD ET AL.

Table 5. Effect of PU operation on the histometrical parameters of males’ large intestinal parts at 12 wk of age. Treatments GIT part C

CO

T1

VL DL MM TMT SM MA S TWT VL DL MM TMT SM MA S TWT VL DL MM TMT SM MA S TWT

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

3.97 3.322 0.98 8.272 1.144 23.486 2.06 34.962 15.682 7.428 2.062 25.172 2.508 16.982 3.396 48.058 9.922 5.886 1.808 17.616 2.842 20.268 1.562 42.288

T2 b

0.118 0.126b 0.144 0.136b 0.095b 2.054 0.217 2.198b 0.46 0.115c 0.322 0.673 0.298b 0.498 0.201 1.032b 0.403 0.13 0.125 0.547 0.308 0.838 0.04 0.867

6.674 6.55 0.972 14.196 1.47 24.686 1.94 42.292 16.492 7.482 2.98 26.954 5.15 17.014 3.618 52.736 10.122 5.912 1.848 17.882 2.862 20.268 1.576 42.588

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T3 a

0.496 0.479a 0.065 0.605a 0.063a 1.83 0.279 1.593a 0.364 0.409c 0.335 0.613 0.211a 0.471 0.349 1.135a 0.327 0.137 0.116 0.494 0.299 0.838 0.049 0.974

4.97 3.964 0.986 9.92 1.282 23.886 2.186 37.274 16.476 8.936 2.346 27.758 2.846 17.784 4.344 52.732 9.946 5.946 1.848 17.74 2.882 20.468 1.616 42.706

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T4 b

0.118 0.32b 0.142 0.408b 0.09a,b 1.886 0.118 2.046a,b 1.33 0.461a,b 0.139 1.137 0.432b 0.193 0.224 1.44a 0.421 0.155 0.16 0.649 0.291 0.723 0.064 0.83

4.77 3.944 0.966 9.68 1.28 23.686 1.986 36.632 15.892 8.196 2.202 26.29 2.264 17.032 3.922 49.508 9.923 5.966 1.848 17.737 2.822 20.428 1.622 42.609

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T5 b

0.274 0.33b 0.125 0.518b 0.091a,b 1.958 0.191 2.167a,b 0.63 0.301b,c 0.16 0.717 0.122b 0.139 0.139 0.737a,b 0.402 0.161 0.106 0.574 0.295 0.743 0.072 0.826

6.874 6.47 0.972 14.316 1.45 24.686 1.942 42.394 16.092 9.556 1.996 27.644 2.918 17.214 4.44 52.216 9.948 6.086 1.868 17.902 2.782 20.354 1.662 42.7

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.579a 0.54a 0.065 0.833a 0.046a 1.617 0.243 1.032a 0.482 0.508a 0.107 0.844 0.246b 0.486 0.389 1.543a 0.401 0.074 0.116 0.487 0.274 0.784 0.077 0.588

Mean values with common superscript in rows differ significantly (P < 0.01). SM and TWT of cecum and TWT of colon means values with common superscript in rows differ significantly (P < 0.05). C: cecum; CO: colon; R: rectum; Vl: villi length; DL: depth of Crypts of lieberkuhn; MM: muscularis mucosa; TMT: total mucosa thickness (VL+DL+MM); SM: submucosa; MA: muscularis; S: serosa; TWT: total wall thickness (TMT+SM+MA+S). a-c a-c

increasing with endocrine secretions (Bacon et al., 1987; Haddad and Mashaly, 1990; Proudman et al., 1995; Kermanshahi et al., 2010).

Effect of the PU Operation on Histometric Parameters of the Digestive System The present study proved that the removal of the UG has noticeable significant effects only on the intestinal histometric aspect of Akar Putra chickens concerning the villi length, absorptive area of villi, depth of crypts of lieberkuhn, muscularis mucosa, submucosal layer, muscular layer, and serosal layer. Also, it illustrated that the increase in intestinal wall thickness means improvement in intestinal activity in digestion and absorption functions. On the other hand, the results demonstrate that the vigorous absorptive part is mainly the duodenum, extending to the jejunum and ileum. This observation was similar with (Al-Tememy et al., 2011) who reported that the duodenum is the main part of the small intestine in digestive and absorptive functions because it has more wall thickness compared with other parts of the small intestine, followed by the jejunum then ileum in this respect. Our results provided many insights into the differentiation in intestinal wall thickness among treatments, attributed mainly to the difference in the thickness of the mucosal layer, especially

because of villi length and depth of the intestinal glands (crypts of lieberkuhn). Increasing villi length means increasing the absorptive area, while an increase in the depth of crypts means more activity in degeneration of absorptive epithelial cells that cover the villi, and more activity in releasing digestive enzymes. The villus morphological feature corresponds with an increase in feed intake and rapid growth rate of broilers, suggesting a possibility of intestinal villus histological alterations related to intestinal function (Ziswiler and Farner, 1972; Yamauchi and Isshiki, 1991). In the same regard, the study agrees with (William and Linda, 2000) who suggested that the villus was larger in the duodenum but gradually shortens and thickens caudally. The ileum villus is shorter (Yamauchi et al., 1993) and lower (Yamauchi et al., 1995) than that of the duodenum and this indicates that the absorptive function of the ileum villus is less active than that of intestinal proximal parts; this may be due to the fact that nutrients have already been absorbed by the time the intestinal contents reach the intestinal proximal parts (Yamauchi, 2002). Based on the results of the present study, the submucosal layer in the wall of the intestine was lacking activity in birds due to the absence of Brunner glands, compared with mammals. That agrees with (William and Linda, 2000) who suggested that the wall of the intestine in chickens was similar to that of mammals, but the absence of duodenal glands and the thin submucosa in chickens are noticeable.

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R

Parameter

7

PU EFFECTS ON GH AND DIGESTIVE SYSTEM HISTOLOGY Table 6. Effect of PU operation on the histometrical parameters of females’ large intestinal parts at 12 wk of age. Treatments Parameter

C

VL DL MM TMT SM MA S TWT VL DL MM TMT SM MA S TWT VL DL MM TMT SM MA S TWT

CO

R

T1 5.46 6.178 0.808 12.446 1.35 18.148 1.96 33.904 14.12 6.744 1.278 22.142 2.82 15.514 3.474 43.95 9.782 5.726 1.668 17.176 2.742 20.268 1.492 41.678

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T2 0.758 0.405 0.052 0.859 0.133 0.412 0.079 1.078 0.101 0.237 0.148 0.218 0.349 0.114 0.166 0.529 0.498 0.192 0.17 0.802 0.256 0.838 0.083 0.767

5.282 6.232 0.98 12.494 1.368 19.168 2.07 35.1 14.97 6.944 1.444 23.358 2.124 15.33 3.626 44.438 10.042 5.774 1.728 17.544 2.802 20.288 1.57 42.204

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T3 0.562 0.394 0.232 0.594 0.107 1.135 0.185 1.414 0.436 0.161 0.169 0.577 0.16 0.196 0.273 0.251 0.346 0.18 0.157 0.65 0.265 0.825 0.05 0.879

5.462 6.432 0.844 12.738 1.344 18.768 2.09 34.94 14.64 6.864 1.484 22.988 2.202 15.868 3.052 44.11 9.892 5.854 1.768 17.514 2.842 20.554 1.596 42.506

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T4 0.468 0.22 0.04 0.488 0.13 0.76 0.202 1.062 0.396 0.219 0.231 0.499 0.119 0.218 0.101 0.267 0.454 0.178 0.173 0.767 0.267 0.686 0.071 0.772

5.662 6.232 0.904 12.798 1.544 18.568 2.072 34.982 14.776 6.71 1.836 23.322 2.776 15.816 3.184 45.098 9.889 5.914 1.808 17.611 2.902 20.386 1.632 42.531

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

T5 0.428 0.334 0.083 0.64 0.081 0.775 0.213 1.222 0.213 0.302 0.114 0.305 0.202 0.26 0.134 0.226 0.423 0.169 0.109 0.64 0.349 0.766 0.07 0.854

5.462 6.432 0.924 12.818 1.484 18.168 2.072 34.542 14.93 6.938 1.836 23.704 2.41 15.916 3.93 45.96 9.908 6.114 1.788 17.81 2.902 20.434 1.706 42.852

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.248 0.323 0.101 0.473 0.119 0.413 0.102 0.779 0.464 0.356 0.15 0.762 0.295 0.316 0.214 1.081 0.423 0.067 0.137 0.513 0.349 0.74 0.074 0.654

C: cecum; CO: colon; R: rectum; Vl: villi length; DL: depth of Crypts of lieberkuhn; MM: muscularis mucosa; TMT: total mucosa thickness (VL+DL+MM); SM: submucosa; MA: muscularis; S: serosa; TWT: total wall thickness (TMT+SM+MA+S).

CONCLUSION AND SUGGESTIONS Based on the research results and discussion, it can be concluded that stopping the function of the UG by a partial surgical removal technique caused significant improvement in the serum GH concentration level and digestive system histology of Akar Putra chickens. The PU operation effect appears prominent in male and female GH concentration at wk 12 and in the histometric parameters of the small intestine. It is assumed that the oil of the UG has a positive impact on the body’s performance after removal of the gland.

ACKNOWLEDGMENTS This paper was supported by the University of Putra Malaysia in 2015. The authors wish to thank Prof. Saad A. Naji, Poultry Science scientist, Department of Animal Resources, Dean of Agriculture faculty, University of Al-qadisiya (Iraq), for the technical assistance.

REFERENCES Ann, J. 2004. Veterinary Histology. Chapter 32. University of Illinois. Al-Tememy, H. S. A., F. K. Al-Jaff, E. H. Al-Mashhadani, and S. J. Hamodi. 2011. Histological effect of inclusion different levels of coriander oil in broiler diet on small intestine. Diyala Agri. Sci. J. 3:En1–En11. Aptekmann, K. P., S. M. Artoni, M. A. Stefanini, and M. A. Orsi. 2001. Morphometric analysis of the intestine of domestic quails (Coturnix coturnix japonica) treated with different levels of dietary calcium. Anat. Histol. Emberyol. 30:277–280.

Aughey, E., and F. L. Frye. 2001, Comparative Veterinary Histology with Clinical Correlates, First edition, Manson publishing/the veterinary press. Bacon, W. L., W. H. Burke, N. B. Anthony, and K. E. Nestor. 1987. Growth Hormone Status and Growth Characteristics of Japanese Quail Divergently Selected for Four-Week Body Weights1. Poult. Sci. 66:1541–1544. Bellairs, R., and M. Osmond 2005. Atlas of Chick Development. Academic Press. Chen, Y. H., M. J. Kou, F. M. Pan, and L. L. Lu. 2003. Effects of uropygial gland removal on the growth performance and plasma characteristics in female white roman goslings from 3 to 10 weeks of age. Tunghai J. 44:7–13. Davidson, M. W., and M. Abramowitz. 2002. www.micro.magnet. fsu.edu/micro/gallery/prostaglandin/prostaglandin.html Duncan, B. D. 1955. Multiple range and multiple f test. Biometrics 11:1–42. Genstat. 2003. Genstat 5.0 Release 4.23DE. Lawes Agric, Trust, Rothamsted Exp. Stn., UK. Girouard, H., and R. Savard. 1998. The lack of bimodality in the effects of endogenous and exogenous prostaglandins on fat cell lipolysis in rats. Prostaglandins. 56:43–52. Goodwin, D. 1983. Pigons and Doves of the World, 3rd el-cornell University press, lthaca NewYork. Haddad, E. E., and M. M. Mashaly. 1990. Effect of thyrotropinreleasing hormone, triiodothyronine, and chicken growth hormone on plasma concentrations of thyroxine, triiodothyronine, growth hormone, and growth of lymphoid organs and leukocyte populations in immature male chickens. Poult. Sci. 69:1094–1102. Harden, R. L., and T. P. Oscar. 1993. Thyroid hormone and growth hormone regulation of broiler adipocyte lipolysis. Poult. Sci. 72:669–676. Jacob, M. C. 1976. Bird waxes. In PE. kolattukudy (Ed.). Chemistry and Biochemistry of Natural Waxes. Amsterdam: Elsevier, p. 93– 146. Jawad, H. S., L. H. B. Idris, S. A. Naji, M. B. Bakar, and A. B. Kassim. 2015. Partial Ablation of Uropygial Gland Effect on Production Performance of Akar Putra Chicken. Int. J. Poult. Sci. 14:213–221. Kermanshahi, H., M. R. Nassiri, and M. A. Heravi. 2010. Effect of feed restriction and different energy and protein levels of the diet

Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on March 23, 2016

GIT part

8

JAWAD ET AL. Vasilatos-Younken, R., X. H. Wang, Y. Zhou, J. R. Day, J. P. McMurtry, R. W. Rosebrough, and F. Tomas. 1999. New insights into the mechanism and actions of growth hormone (GH) in poultry. Dom. Ani. End. 17:181–190. Vincze, O., C. I. V´ ag´ asi, I. Kov´ acs, I. Galv´ an, and P. L. Pap. 2013. Sources of variation in uropygial gland size in European birds. Biological Journal of the Linnean Society. 110: 543–563. Wang, C. Y., Y. Wang, J. Li, and F. C. Leung. 2006. Expression profiles of growth hormone-releasing hormone and growth hormonereleasing hormone receptor during chicken embryonic pituitary development. Poult. Sci. 85:569–576. William, J., and M. Linda. 2000, Color atlas of Veterinary Histology, second edition, Awolter Klumer Company, Hoboken, United States. Yamauchi, K. E., and Y. Isshiki. 1991. Scanning electron microscopic observations on the intestinal villi in growing White Leghorn and broiler chickens from 1 to 30 days of age. Brit. Poult. Sci. 32: 67–78. Yamauchi, K., E. Nakamura, and Y. Isshiki. 1993. Development of the intestinal villi associated with the increased epithelial cell mitosis in chickens. Ani. Sci. and Tech. 64:340–350. (Japan). Yamauchi, K., K. Yamamoto, and Y. Isshiki. 1995. Morphological alterations of the intestinal villi and absorptive epithelial cells in each intestinal part in fasted chickens. Japanese Poult. Sci. 32: 241–251. Yamauchi, K. E. 2002. Review on Chicken Intestinal Villus Histological Alterations Related with Intestinal Function. The J. Poult. Sci. 39:229–242. Zheng, J. X., Z. Z. Liu, and N. Yang. 2007. Deficiency of growth hormone receptor does not affect male reproduction in dwarf chickens. Poult. Sci. 86:112–117. Ziswiler, V., and D. S. Farner. 1972. Digestion and digestive system. Avian Biol., Vol 2. pp: 343–430. Academic press. London.

Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on March 23, 2016

on growth performance and growth hormone in broiler chickens. J. Biol. Sci., 10:25–30. Montalti,, D., and A. Saliban. 2000. Uropygial gland size and avian habitat. Ornitol. Neotrop. 11:297–306. Mitchell, M. A., and M. W. Smith. 1991. The effects of genetic selection for increased growth rate on mucosal and muscle weights in the different regions of the small intestine of the Domestic fowl (Gallus domesticus). Comp. Bioch. and Physiol. 99:251–258. Moyer, B., A. N. Rock, and D. H. Clayton. 2003a. Experimental test of the importance of preen oil in rock doves (Columba livia). The Auk. 120:490–496. Moyer, B. R., A. J. Pacejka, and D. H. Clayton. 2003b. How birds combat ectoparasites. Curr. Ornithol. 117. Parmer, T. G., L. B. Carew, F. A. Alster, and C. G. Scanes. 1987. Thyroid function, growth hormone, and organ growth in broilers deficient in phosphorus. Poult. Sci. 66:1995–2004. Proudman, J. A., K. A. Krishnan, and K. Maruyama. 1995. Ontogeny of pituitary and serum growth hormone in growing turkeys as measured by radioimmunoassay and radioreceptor assay. Poult. Sci. 74:1201–1208. Sakamoto, K., H. Hirose, A. Onizuka, M. Hayashi, N. Futamura, Y. Kawamura, and T. Ezaki. 2000. Quantitative study of changes in intestinal morphology and mucus gel on total parenteral nutrition in rats. J. Surg. Res. 94:99–106. Scanes, C. G., S. Harvey, J. A. Marsh, and D. B. King. 1984. Hormones and growth in poultry. Poult. Sci. 63:2062–2074. Steel, R. G. D., and J. H. Torrie. 1980. Principles and Procedures of Statistics: A Biometrical Approach. 2nd Ed. McGraw - Hill Book Co., NY. Vasilatos, Y. R., and C. G. Scanes. 1991. Growth hormone and insulin-like growth factors in poultry growth: required, optimal, or ineffective?. Poult. Sci. 70:1764–1780.