EFFECT OF ACETIC ACID ADDITION ON GROWTH AND SOME PHYSIOLOGICAL AND IMMUNOLOGICAL CHARACTERISTICS OF GROWING RABBITS.

EFFECT OF ACETIC ACID ADDITION ON GROWTH AND SOME PHYSIOLOGICAL AND IMMUNOLOGICAL CHARACTERISTICS OF GROWING RABBITS.

I. E. Ismail¹ and A. M. A. Bealish²

¹ Poultry Department, Faculty Agriculture, Zagazig University, Zagazig 44511, Egypt.

²Poultry Breeding Department, Animal Production Research Institute, Agriculture  Research  Center, Dokki, Giza, Egypt.

 This experiment was carried out to evaluate the effect of acetic acid addition on growth and some physiological and immunological characteristics of growing rabbits. A total of 36 New Zealand White (NZW) weaning male rabbits with average live body weight of 685 ± 25 g were randomly divided into four treatment groups (9 rabbits each). The 1^st group received basal untreated pelleted diet and served as a control group, while the 2^nd, 3^rd and 4^th groups fed the basal diet with 0.5, 1.0 % and 1.5% acetic acid, respectively.

           The obtained results showed that live body weight and feed intake did not significantly differed due to treatments. Mortality rate significantly (P<0.05) decreased with increasing acetic acid level than those of low level (0.5 %) and of the control group. Red blood cells (RBCs) count, hemoglobin (Hb %), packed cell volume (PCV, %), lymphocyte and heterocyte percentages of blood were significantly and white blood cells (WBCs) insignificantly differed due to acetic acid treatment. Blood plasma contents of total protein, albumin and globulin insignificantly increased and total lipids, triglycerides, totalcholesterol, uric acid and transaminase enzymes of liver (AST and ALT) were significantly (P<0.05) differed due to acetic acid treatment. Rabbits which supplemented with 1.5% of acetic acid were accompanied by the highest values of these traits than those of control group. The activities of digestive enzymes (amylase, lipase and protease) were significantly (P<0.05) increased in groups treated with different levels of acetic acid compared with control group. Number of colonies bacteria Escherichia coli and Salmonella were significantly (P<0.05) decreased in gut of rabbit groups due to acetic acid treatment compared with those of control group. Ileum and ceacum pH values were insignificantly differed due to treatments.

The obtained results indicated that addition of acetic acid showed improvement in digestive enzyme activities, some blood hemato-biochemical constituents, immunological traits and decreasing mortality rate of growing rabbits, especially in rabbits received 1.5% of acetic acid.

Key words: Acetic acid, blood picture, blood components, growth performance, rabbits.

Rabbit farming has significant potential and useful contribution in improving meat supply, food security and national economy in developing countries (Anjana and Goswami, 2012 and Ebeid et al., 2013). Although there is an increasing interest in enterprises of raising rabbits with different sizes in Egypt, several difficulties and constraints stand against the successfulness of these enterprises. Digestive diseases are currently the main cause of morbidity in growing rabbits, resulting in dramatic mortality rate increases in fattening rabbitries (Rosell et al., 2009). The activity of the digestive enzymes in pancreatic tissue is low after 5 days post-weaning due to interaction with out factors which may increased the risk of developing post-weaning diarrhea (Hedemann and Jensen 2004).

In livestock production system, antibiotics are commonly used to animals to prevent disease and metabolic disorders, as well as feed efficiency. However, in recent years, public concern over routine use of antibiotics, in livestock nutrition has increased due to the enhance of antibiotics resistant bacteria that may represent a threat to human health. Consequently, considerable effort has been devoted towards developing alternatives to antibiotics. Organic acids traditionally have been used as food preservatives. (Naidu, 2000) reported that these acids retard microbial growth and contribute desirable sensory properties to a number of foods. Acetic acid historically diluted in the form of vinegar, has been utilized perhaps longer than any other preservatives for its antimicrobial effect, which influences food keeping-quality, wholesomeness, and safety. Organic acids have inhibiting action on the intestinal bacteria competing with the host for available nutrients, so these acids are predictable replacement for antibiotics in rabbits diet (Hyden, 2000 and Falcao-e-Cunha et al., 2007). Organic acids used in feed  industry regularly for contracts and their many benefits are now admitted, whereas, the antifungal property of organic acid and antibacterial activity against anaerobic opportunistic pathogens (Cherrington et al., 1990; Skrivanova et al., 2006). The increased in pressure on livestock industry to phase out the use of prophylactic dosages of antibacterial growth promoters in the European Union due to microbial resistance in animals and human and the potential to do some in other parts of world has stimulated increased interest in alternative natural growth promoters (Fature and Matanmi, 2008).

Therefore, the present study intent to investigate the effect of diet supplemented with acetic acid on growth performance, some blood constituents and gut bacteria count in growing rabbits.  

MATERIALS AND METHODS

 The present study was performed at rabbitry farm of the Department of Poultry, Faculty of Agriculture, Zagazig University, Zagazig, Egypt. A total number of 36 male New Zealand White (NZW) rabbits weaned at 35 days of age with average weight of 685 ± 25 g were randomly divided into four treatment groups (9 rabbits each) in completely simple randomized design. The 1^st group was received untreated basal pelleted diet and served as a control group. Meanwhile, the 2^nd, 3^rd and 4^th groups' fed on the same basal diet supplemented with 0.5%, 1% and 1.5% acetic acid, respectively. Rabbits were individually housed in galvanized wire cages (Dimensions of 45 × 35 × 40 cm) until the end of the experimental period. All rabbits were kept under the same managerial, hygienic and environmental conditions, fed ad-libitum and fresh water was automatically available all the time by stainless steel nipples fixed in each cage. All rabbit cages were equipped with feeders and nipples. The chemical composition of the basal diet was 18. % crude protein, 13.5% crude fiber, 2.31% ether extract and 2650 digestible energy (Kcal/kg). The diet was formulated according to NRC (1977).

Live body weight (LBW) was recorded individually for each rabbit at 2, 4 and 6 weeks of the experimental period. Daily feed consumption (DFS) was determined precisely and calculated as gram per rabbit per day, during the whole experimental periods. Mortality rate (MR, %) was recorded daily throughout the experimental period.

At the end of experimental period four mail of each group were weight, sacrificed for slaughtering. Blood samples were collected into 10 ml EDTA tubes, and then gently mixed. The erythrocyte (RBCs), the total leukocyte (WBCs) and the differential leukocyte counts, the packed cell volume (PCV) and hemoglobin (Hb) concentrations were determined as described by Ewuola and Egbunike (2008). Blood plasma samples were stored for further determination of total protein (TP), albumin (Alb), total lipids (TL), tri-glycerid (TG) and total cholesterol (TC). While, plasma globulin (Glb) was deduced as the difference between TP and Alb values (Fonseca et al., 2004). Uric acid (UA) was determined according to (Tietz, 1986), Alanine-aminotransferase (ALT) and Aspartate- aminotransferase (AST) were determined according to Reitman and Frankel (1957). Amylase activity was determined using the method of Somogyi (1960). Lipase activity was assayed using the method described by Tietz and Fiereck (1966). Protease activity was analyzed using the method of Lynn and Clevette-Radford (1984). On slaughtering, gastrointestinal removed for collection of small intestine and caecum contents into tubes to determine pH values and bacteria number, pH of caecum and ileum using pH digital-pH meter. E. coli bacteria Inventory was carried out according to the method described by Cheney et al. (1979), while Salmonella count carried out according to the method of Giannella et al. (1973).

Statistical analysis

           The obtained data were statistically analyzed in completely simple randomized design (Snedecor and Cochran, 1982) using SAS (1998).

Data was analyzed by adopting the following model:

Y_ij  = U + T_i + e_ij

Y_ij  = An observation, U  = The overall mean, T_i = The effect due to treatment levels (i = 0.5, 1 and 1.5% acetic acid), e_ij   = A random error.

           Differences among means were tested by Duncan's multiple range test (Duncan, 1955).

RESULTS AND DISCUSSION     

Growth performance:

         The obtained results of live LBW and DFS insignificantly affected by treatments throughout all the experimental periods (Table 1). Our finding agreement with those obtained by Amaefule et al. (2011) in growing rabbits and Kopecky et al. (2012) in broiler they showed that diets supplemented with acetic acid did not significantly altered growth performance traits. On the other hand, these results partially agree with those obtained by Radwan and Abdel-Khalek (2007) who explained that there were no significant differences in feed intake of all experimental growing NZW rabbits due to using 0.5% of acetic acid, while the final live total body weight significantly increased when used 0.5% acetic acid compared with control group. Mortality rate significantly (P<0.05) decreased linearly with increasing dietary acetic acid level. These results are in agreement with those obtained by Romero et al. (2010) and Romero et al. (2011) who reported a sharp reduction in the mortality rate due to diarrhoeal syndromes when rabbits were fed diets including short-chain organic acids. Skrivanova et al. (2006) stated that beyond the antifungal property of organic acids, some other benefits such as their antibacterial activity against anaerobic opportunistic pathogens and reduce mortality rate due to digestive diseases. Also, Cardinali et al., 2007 observed that when rabbits feed organic acids drastically reducing the mortality percentage in a

context of high incidence of digestive diseases or after an experimental infection with harmful pathogenic bacteria.

Blood heamatology:

    Data in Table 2 showed that WBCs count insignificant changes in rabbit groups treated with all various levels of acetic acid compared with these of the control group. However, rabbits treated with 1.5% acetic acid increased insignificantly than other groups and control group. Lymphocytes and heterocyte percentages significantly (P<0.05) increased in rabbit groups treated with different levels of acetic acid compared with control group. These results may be due to increase the activity of immune system. That's where, the response of gut-associated lymphoid tissue to the diet supplemented with organic acids in growing rabbit to be determined (Romero et al., 2011). Since the appendix and Peyer's patches serve a major role in the synthesis of antibodies against intraluminal antigens (Dasso et al., 2000). The count of RBCs, Hb % and PCV % significantly (P<0.05) decreased in rabbits group fed on diet supplemented with 1.5% acetic acid compared with the control or other treated groups (Table 2). These results are in agreement with those obtained by Askar (2012) who stated that WBCs number and the percentage of lymphocyte significantly increased in broiler treated by phenyl lactic acid. Abdel-Kafy et al. (2008) showed that RBCs count; hemoglobin concentrations and hematocrit percentage were decreased in growing NZW rabbits treated by acetic acid compared with control group. Wang et al. (2009) found in pigs that lymphocyte percentage linearly increased as dietary phenyl lactic acid increased and WBCs counts tend to increase as phenyl lactic acid level increase. The increase of WBCs number may be due to the activation of animals defence mechanisms and immune system (Abdel-Tawab and Abbassy. 2012). Wang et al. (2009) and Czerwinski et al. (2010) reviewed that organic acids could stimulate the immune system, it has been clearly established that several organic acids can affect microorganisms population of gut intestine that are necessary for gut immune system development.

Blood biochemical constituents:

The results of TP, Alb and Glb concentrations due to acetic acid supplementation insignificantly increased in rabbits group treated with 1.5% acetic acid compared with other groups and control group (Table 3). these findings are in agreement with those obtained by Radwan and Abdel-Khalek (2007) in growing rabbits, Wang et al. (2009) in pigs and Askar (2012) in quail they found that TP and Alb concentrations were higher when animals fed treated diet supplemented with acetic acid in rabbits or supplemented with phenyl lactic acid in (pigs and quail) compared with the values of the

control group, the authors reminded that the highest value of total protein accompanied by increasing acids level.

Total lipids significantly (P<0.01) increased in rabbit groups treated with different levels of acetic acid compared with the untreated group. While, TG and TC significantly (P<0.01) increased in rabbits treated by 1 and 1.5% of acetic acid only compared with the control group. While TG and TC concentrations were decreased with low level of acetic acid compared with untreated group. The results agree partially with those observed by Radwan and Abdel-Khalek (2007) who found that total lipid concentration increased in rabbit treated with acetic acid; however the author observed that cholesterol level significantly decreased compared with the untreated group. Meanwhile, our findings differ with the result revealed by Hassan et al. (2008) who showed that total lipids, triglycerides and cholesterol significantly decreased due to the treatment by acetic acid in laying hen. Sheikh et al. (2010) observed that blood contents of cholesterol did not significantly differ as results of treatment by some organic acids in broiler.

Markedly decrease in AST activity in groups treated with 0.5 and 1% of acetic acid, while the activity of AST significantly (P<0.05) increased in rabbits treated with 1.5% acetic acid compared with control group  (Table 3). ALT activity was significantly (P<0.01) increased in rabbit groups treated by 1.0 and 1.5% of acetic acid compared with control group. While, uric acid significantly (P<0.05) decreased in all treated groups compared with control group. The activities of AST and ALT enzymes were generally decreased in rabbits group treated with low level of acetic acid (Table 3). The liver is responsible for detoxification process of metabolism and biosynthesis of energetic macromolecules for different essential functions (Aly et al., 1997). Also, it is the first organ to face any foreign molecule that is carried through portal circulation and it is subjected to most damage. The increase of the indicated enzymes is reflecting the lesion in liver (El-Demerdash and Nasr, 2014). In addition, AST and ALT are important enzymes as specific indicators for liver function and in plying a role in amino acids catabolism and biosynthesis (Harper, 1979).

Result in (Table 4) revealed that digestive enzymes (amylase, lipase and protease) activities significantly (P<0.01) and linearly increased in rabbit groups treated with various levels of acetic acid compared with control group. Whereas rabbits group that received 1.5% of acetic acid showed the highest value of different digestive enzymes. These results may be due increase the synthesis of digestive enzymes consequence, lead to improved digestion. Whereas, Cardinali et al. (2007) explained that further benefits of organic acids that would stem from a direct stimulation of gastrointestinal mucosa growth. These results are in agreement with those observed by Abdel-Kafy et al. (2008) who found that activities of amylase

and protease enzymes in small intestine were higher of rabbit groups exposure for heat and acetic acid compared with control group. Organic acids in the popeline help to increasing digestibility of proteins and regulating the micro flora in the gut (Philipsen, 2006). 

The number of colonies bacteria Escherichia coli and Salmonella were significantly (P<0.05) decreased in gut of rabbit groups which treated by acetic acid compared with those of the control group. Organic acids have anti-biotic like action, through inhibiting action of the intestinal bacteria (Hyden, 2000). Acidification of diets with organic acids is widely used to microbial degradation and improving productive performance of poultry and rabbits (Panda et al., 2006 and Radwan and Abdel-Khalek, 2007). Also' many investigators reviewed that chick fed on organic acids reduced E.coli lesion score as compared to those fed on the antimicrobial compounds (Waldroup et al., 1995, Engberg et al., 2001 and Panda et al., 2006).

Data in Table (4) showed that ileum and cecum pH were insignificantly decreased in rabbit groups fed on diets supplemented with different levels of acetic acid when compared with unsupplemented group. Our results are in agreement with those obtained by El-Allawy (2001) who found that citric acid (5.0 g/ kg diet) had no significant effect on rabbit cecum pH values. Radwan and Abdel-Khalek (2007) observed that diets supplemented with organic acids (acetic acid and lactic acid) insignificantly increased volatile fatty acids production which reflected on reduce the pH values of cecum and ileum.Also, Romero et al. (2011) observed that caecal pH value was decreased with increasing caecal volatile fatty acids when rabbits fed diets supplemented with organic acids.  

In conclusion, the current study proved that acetic acid addition to growing rabbit diets with level of 1.5% could be exerting some positive effects on some blood biochemical and immune constituents and rabbit performance.

REFERENCES

Abdel-Kafy, E. M.; Ali, W. A. H.; Shabaan, H. A. and Azoz, A. A. A. (2008). Influence of short heat exposure, balanced feed restriction and acetic acid on gastrointestinal tract and mortality during post-weaning in rabbits with emphasis in heat shock protein. Egypt. Poultry Science, 28 (1): 299-310.

Abdel-Tawab, M. H and Abbassy, M. A. (2012). Adverse haematological and biochemical effects of certain formulated insecticides in Male Rats. Research Journal Environ. Toxic., 6 (4):160-168.

Aly, N. M.; Abou-El-Khear, R. K. and El-Bakary, A. S. (1997). Immunological, heamatological studies on albino rats treated with warfarin. Journal Alex.  Of Science Exch., 18:265-275.

Amaefule, K. U.; Mbagwu, I. I. and Inyang, N. E. (2011). Performance, nutrient utilization and intestinal environment of weaned rabbits fed diets supplemented with organic acids in the humid tropics. Nigerian Journal of Animal Science, 13: 59- 69.

Anjana, C. S. and Goswami, R. N. (2012). Selection indices for improving body weight in New Zealand White breed of rabbit maintained at the hilly Indian state of Meghalaya. 10th  World Rabbit Congress, 3-6 September, Sharm El-Sheikh, Egypt. pp. 25-29

Askar, A. A. (2012). Some physiological and immunological effects of phenyl lactic acid in broiler chicks. Egyptian J. Anim. Prod., 49 (1): 87-93.

Cardinali, R.; Rebollar, P. G.; Dal Bosco A.; Cagiola, M.; Crotti, S.; Scicutella, N.; Rutili, D. and Castellini, C. (2007). Integrazione alimentare di acidi organici ed oli essenziali microincapsulati nel controllo delle infezioni enteriche del coniglio. In Proc. Giornate di Coniglicoltura ASIC, Forlì, Italy, 137.

Cheney, C. P.; Boedeker, E. C. and Formal, S. B. (1979). Quantitation of the adherence of an enteropathogenic Escherichia coli to isolated rabbit intestinal brush borders. Infection and Immunity, 26: (2) 736-743.

Cherrington, C. A.; Hinton, M. and Chopra, I. (1990). Effect of short-chain organic acids on macromolecular synthesis in Escherichia coli. Journal of Applied Bacteriol., 68: 69-74.

Czerwinski, J.; Hojberg, O.; Smulikowska, S.; Engberg, R. M. and Mieczkowska, A. (2010). Influence of dietary peas and organic acids and probiotic supplementation on performance and caecal microbial ecology of broiler chickens. Br.  Poultry  Sci., 51: 258- 269.

Dasso, J. F.; Obiakor, H.; Bach, H.; Anderson, A. O. and Mage, R. G. (2000). A morphological and immunohistological study of the human and rabbit appendix for comparison with the avian bursa. Dev. Comp. Immunol., 24: 797-814.

Duncan, D. B. (1955). Multiple range and multiple F-test. Biometrics, 11:1-42.

Ebeid, T.; Zeweil, H.; Basyony. M.; Dosoky, W, M. and Badry, H. (2013). Fortification of rabbit diets with vitamin E or selenium affects growth performance, lipid peroxidation, oxidative status and immune response in growing rabbits. Livestock Science, 155:323-331.

El-Allawy, Hewida, M. (2001). The use of bio-feed additives to improve rabbit performance. Ph.D. Thesis, Fac. Agric., Cairo Univ., Giza, Egypt.

El-Demerdash, F. M. and Nasr, H. M. (2014). Antioxidant effect of selenium on lipid peroxidation, hyperlipidemia and biochemical parameters in rats exposed to diazinon. J. Trace Elem. Med.  Biol., 28(1):89-93.

Engberg, M. R.; Nuria, C. and Bent, B. J. (2001). An overview of the effect organic acids on gut flora and gut health. Danish Institute of Agricultural Sciences, Research Centre Foulum, Denmark.

Ewuola, E. O. and Egbunike, G. N. (2008). Haematological and serum biochemical response of growing rabbit bucks fed dietary fumonisin B. Afr. J. Biotechnol., 7: 4304-4309.

Falcao-e-Cunha, L., Castro-Solla, L.; Maertens, L.; Marounek, M.; Pinheiro, V.; Freire, J. and Mour, J. L. (2007). Alternatives to antibiotic growth promoters in rabbit feeding: a review. World Rabbit Sci., 15: 127 – 140.

Fature, A. A. and Matanmi, I. O. (2008). The effect of probiotics supplementation on the growth performance of two strains of cockerels, Journal of Central European Agriculture, 9 :405-410

Fonseca, A. P.; Falcão, L.; Kocher, A. and Spring, P. (2004). Effect of dietary mannan oligosaccharides in comparison to oxytetracyclin on performance of growing rabbits. Proc. 8th World Rabbit Congress,  7-10 September, Mexico, pp. 829–833.

Giannella, R. A.; Formal, S. B.; Dammin, G. J. and Collins, H. (1973). Studies of fluid secretion, mucosal invasion, and morphologic reaction in the rabbit ileum. J. Clin. Invest., 52: 441-453.

Hassan,M. S. H.; Abdalla, E. A. and Abdel Samad, M. H. (2008). Physiological and immunological roles of acetic acid for improving egg production and decreasing pollution and ammonia level in local laying hens houses. Egypt. Poultry Sci., 28 (1): 223-250.

Harber, C. (1979). Wernicke’s encephalopathy: A more common disease than realized. A neuropathological study of 51 cases. Journal of Neurol. Neurosurg. Psychiatry, 42:226-231.

Hedemann, M. S. and Jensen, B. B. (2004). Variations in enzyme activity in stomach and pancreatic tissue and digest in piglets around weaning. Arch. Anim. Nutr.; 58 (1):47-59.

Hyden, M. (2000). Protected acid additives. Feed-Inter., 21: 14–17.

Kopecký, J.; Hrnčár, C. and Weis, J. (2012). Effect of organic acids supplement on performance of broiler chickens. Animal Science Biotechnology., 45 (1) 51-54.

Lynn, K. R. and Clevette-Radford, N. A. (1984). Purification and characterization of hevin, a serin protease from Heveabrazilliensis. Biochemistry Journal, 23:963–964.

Naidu, A. S. (2000). Natural Food Antimicrobial Systems. CRC Press, USA. pp 431-462.

NRC (1977). Nutrient Requirements of Rabbits. National Academy of Science. 2nd 367 revised edition, Washington, USA. pp 1214-1223.

Panda, K.; Ramarao, S. V. and Raju, M. V. (2006). Natural growth promoters have potential in poultry feeding systems. Feed Tech., 10: 23-25.

Philipsen, P. L. J. (2006). Acidifying drinking water supports performance, World Poultry  Sci., 22: 20-21.

Radwan, N. L. and Abdel-Khalek, A. M. (2007). Response of summer stressed growing rabbits to some dietary growth promoters. “Animal Health And Protect - Isah-Soc.Org, Tartu, Estonia, 350-358.

Reitman, S. and Frankel, S. (1957). A colorimetric method for determination of serum glumatic oxaloacetic and glutamic pyruvic transaminases. Ann. J. of Clinical Pathol., 26 : 1 – 13.

Romero, C.; Rebollar, P.G.; Dal Bosco, A.; Castellini, C. and Cardinali, R. (2010). Effect of dietary inclusion of short-chain organic acids on rabbit growth, fattening mortality and development of gut associated lymphoid tissue. In Proc.: XXXV Symposium de Cunicultura, 27-28 Mayo. Segovia, Spain, pp 79-83.

Romero, C.; Rebollar, P.G.; Dal Bosco, A.; Castellini, C. and Cardinali, R. (2011). Dietary effect of short-chain organic acids on growth performance and development of intestinal lymphoid tissues in fattening restricted rabbits. World Rabbit Sci., 19: 133 – 142.

Rosell, J. M.; de la Fuente, L.F.; Badiola, J. I.; Fernández de Luco, D.; Casal, J. and Saco, M. (2009). Study of urgent visits to commercial rabbit farms in Spain and Portugal during 1997-2007. World Rabbit Sci., 17: 127-136.

SAS (1998). SAS Procedure Guide. Release 6.03 Edition. SAS Institute Inc., Cary NC, USA.

Snedecor, G. W. and Cochran, W. G. (1982). Statistical Methods. 6th 374 ed. Iowa State Univ. Press, Ames, U.S.A.

Sheikh, A.; Tufail, B.; Gulam, A. M.; Masood, S. M. and Manzoor, R. (2010). Effect of dietary supplementation of organic acids on performance, intestinal , histopathology and serum biochemistry of broiler chicken. Vet. Med. Int., http/ dx. doi. org/ 10. 4061 / 2010 / 479-485.

Skrivanova, E.; Marounek, M.; Benda, V. and Brezina P. (2006). Susceptibility of Escherichia coli, Salmonella sp. and Clostridium perfringens to organic acids and monolaurin. Vet. Med., 51: 81-88.

Somogyi, M. (1960). Modification of two methods for the assay of amylase. Clin. Chem., 6:23–27.

Tietz, N. W. (1986).  Text book of Clinical Chemistry. Saunders, Philadelphia.

Tietz, N. W. and. Fiereck, E. A. (1966). A specific method for serum lipase determination. Clin. Chim. Acta., 13:352–355.

Wang, J. P.; Yoo, J. S.; Lee, J. H.; Jang, H. D.; Kim, H. J.; Shin, S. O.; Seong, S. I. and Kim, I. H. (2009). Effects of phenyl lactic acid on growth performance, nutrient digestibility, microbial shedding and blood profile in pigs. J. Animal. Sci., 87: 3235-3243. doi: 10.2527/jas. 2008- 1555.

Waldroup, A.; Kaniawato, S. and Mauromoustakos, A. (1995). Performance characteristics and microbiological aspects of broiler fed diets supplemented with organic acids. J. Food. Protec., 58:482-489.

تأثیر اضافة حمض الخلیک على النمو و بعض الصفات الفسیولوجیة والمناعیة فى الارانب النامیة

اسماعیل السید اسماعیل¹ - احمد محمد احمد بعلیش²   

1- قسم الدواجن - کلیة الزراعة - جامعة الزقازیق – محافظة الشرقیة - مصر.

2- قسم بحوث تربیة الدواجن – معهد بحوث الإنتاج الحیوانی – مرکز البحوث الزراعیة – وزارة الزراعة- الجیزة – ج.م.ع.

اجریت هذه التجربة لدراسة تاثیر اضافة حمض الخلیک على اداء النمو وکذلک بعض الصفات الفسیولوجیة والمناعیة فى الارانب حیث تم استخدام عدد 36 ارنب ذکر من سلالة الارانب النیوزیلندى فطمت عند 35 یوم وکان متوسط وزن الارنب (685 ± 25 ) جرام. تم تقسیمهم عشوائیا الى اربع مجموعات (9 ارانب بکل مجموعة). المجموعة الاولى غذیت على العلیقة الاساسیة واستخدمت کمجموعة مقارنة. والجموعة الثانیة والثالثة والرابعة غذیت على العلیقة الاساسیة مضاف لها 0.5% و 1% و 1.5% حمض الخلیک على الترتیب. واوضحت النتائج المتحصل علیها ان وزن الجسم واستهلاک العلف لم یتاثر بصورة معنویة عند اضافة حمض الخلیک بالمستویات المختلفة فى حین انخفضت نسبة النفوق فى المجموعات التى غذیت على علائق مضاف لها حمض الخلیک عند مقارنتها بمجموعة المقارنة. عدد کریات الدم الحمراء وترکیز الهیموجلوبین وترکیز المکونات الخلویة تاثرت بصورة معنویة بالمعاملة بحمض الخلیک حیث ان المجموعة التى تغذت على علیقة مضاف لها 1.5% حمض الخلیک اظهرت اقل قیم لهذه القیاسات عن مجموعة المقارنة والمجموعة التى غذیت على 0.5% حمض الخلیک اظهرت اعلى قیم لهذه القیاسات.عدد کریات الدم البیضاء زادت بصورة غیر معنویة للمجموعات التى تم معاملتها بحمض الخلیک فى حین ان خلایا الدم البیضاء المختلطة والخلایا اللیمفاویة زادت بصورة معنویة عن مجموعة المقارنة. محتوى البلازما من بروتینات الدم الکلیة والالبیومین والجلوبیولین زادوا بصورة غیر معنویة  بینما الدهون الکلیة والجلیسریدات الثلاثیة والکولیستیرول ارتفعوا بصورة معنویة فى بلازما دم المجموعات التى عوملت بحمض الخلیک عن مجموعة المقارنة وکانت اعلى قیم لهذه القیاسات سجلت فى المجموعة التى عوملت 1.5% حمض الخلیک بینما المجموعة التى احتوت 0.5 % انخفض فیها مستوى هذه القیاسات بصورة معنویة عن مجموعة المقارنة. حمض الیوریک انخفض بصورة معنویة فى کل المجموعات التى تم معاملتها بحمض الخلیک عن مجموعة المقارنة. نشاط انزیمات الامیلیز واللیبیز والبروتییز زاد بصورة معنویة عن مجموعة المقارنة فى کل المجموعات التى تم معاملتها بحمض الخلیک فى حین انخفضت درجة الحموضة فى الامعاء والقولون بصورة غیر معنویة فى المجموعات التى تم معاملتها بحمض الخلیک عن مجموعة المقارنة.

التوصیة: أوضحت النتائج المتحصل أن المعاملة بحمض الخلیک ادى الى تحسن فى نشاط الانزیمات الهاضمة وبعض قیاسات الدم الهیماتولوجیة والبیوکیمیائیة وبعض القیاسات المناعیة للارانب النامیة وانخفاض نسبة النفوق خاصة فى المجموعة المعاملة بترکیز 1.5% حمض الخلیک.