جستجوی مقالات مرتبط با کلیدواژه « ال-آرژنین » در نشریات گروه « علوم دام »

During the last stages of incubation, avian mortality commonly happens due to the lack of enough nutrients and amino acids (Fardoost et al. 2019). However, in ovo injection or in ovo feeding is considered a new technique for improving growth of chickens (Ebrahimi et al. 2017). Most studies indicated improving effect of in ovo feeding of nutrients (especially amino acids) on small intestine growth and histology as well as higher absorptive capacity of digestive system (Ebrahimi et al. 2017, 2018a,b; Elwan et al. 2019; Fardoost et al. 2019). Previous studies indicated an improving effect of excess feeding of arginine on growth performance, carcass traits, blood metabolites, and intestinal histology of broilers (Ebrahimi et al. 2013, 2014, 2016b). However, there are few records regarding the impact of in ovo injection of arginine on intestine histology of chickens. Accordingly, the present study was designed to evaluate the effect of in ovo injection of different levels of arginine on carcass traits, blood metabolites, and small intestine histology of broiler chickens.

For this reason, 300 fertile broiler breeder eggs were divided into three treatment groups: 1- 0.5% L-arginine in ovo injection group (100 eggs), 2- 1% L-arginine in ovo injection group (100 eggs), 3- control group included distilled water injected (sham-control subgroup, 50 eggs) and non-injected (control subgroup, 50 eggs). Eggs were then set into the incubator for the first 18 days with the temperature of 37.8°C and six rotations per day. At d 14 of incubation, eggs were injected into the amniotic fluid (Ebrahimi et al. 2017) as follows: 1- in ovo injection of 5 mg L-arginine/ ml distilled water, 2- in ovo injection of 10 mg of L-arginine/ml distilled water, 3- control group included sham-control (in ovo injection of 1 ml distilled water) and control (received no injection). For in ovo injection, solution pH was set at 7.0. At d 18 of incubation, eggs were moved into hatchery boxes. After hatching, chicks were reared for 24 days. During the experiment, chicks received standard commercial diets based on Ross recommendations as starter (0-10 days) and grower (11-24 days), (Table 1). At d 24, blood samples of three chickens per each replicate were collected, centrifuged (3000 rpm for 20 minutes), and serum was separated to evaluate cholesterol, glucose, triglyceride, uric acid, and total protein by the Enzymatic Colorimetric method (Ebrahimi et al. 2017). Then, all birds were weighed, slaughtered, some carcass traits (scalped carcass, eviscerated carcass, breast, thigh, gizzard, proventriculus, pancreas liver without gall bladder, heart, duodenum , jejunum, and ileum were weighed, and their relative weight to chicken body weight were calculated. Also, length of duodenum , jejunum, and ileum was evaluated and their samples were stored in 10% formalin for fixation to evaluate histological parameters (crypt depth, villus height, villus thickness, mucosal thickness, and crypt diameter) using Hematoxylin - Eosin staining method (Ebrahimi et al. 2017). Then, villus height to crypt depth ratios were calculated. Afterwards, data were analyzed based on a completely randomized design by the Proc GLM of SAS software (Ver 9.2). Also, Tukey-Kramer test was used for comparing treatments and results presented as least square means ± standard error.

Based on the results, in ovo injection of different levels of L-arginine did not affect hatchability, day-old chick weight, chick weight to egg weight ratio, 24-day-old chicken weight, feed conversion ratio, relative weight of all carcass traits, cholesterol, glucose, total protein and blood urea nitrogen (P> 0.05), (Table 2). However, serum triglyceride was significantly affected by experimental treatments (P <0.01) and the highest amount was observed in 0.5% L-arginine in ovo injection group (Table 2). In a similar study, Gao et al. (2017) indicated that L- arginine in ovo injection increased weight gain of broiler chickens. Furthermore, Abdolalizadeh Alvanegh et al. (2017) reported the improving effect of in ovo injection of different ratios of L- arginine to L- lysine on chick weight and their carcass traits. Also, they reported higher serum total protein level, while lower blood urea nitrogen of broiler chicks with in ovo injection of different ratios of L- arginine to L- lysine (Abdolalizadeh Alvanegh et al., 2017).Present results indicated no significant effect of in ovo injection of L-arginine on most weight and length parameters of small intestine length (P>0.05); however, relative weight of jejunum was significantly affected by in ovo injection of L-arginine (P<0.05) and the highest amount was observed in 0.5% L-arginine in ovo injection group (Table 3). Present results indicated no significant effect of in ovo injection of L-arginine on duodenal crypt diameter; jejunal villus height, crypt depth and diameter, and mucosal thickness; and ileum villus height, crypt depth, villus height/crypt depth ratio, and mucosal thickness (P>0.05), (Table 3). However, significant effect of in ovo injection of L-arginine was observed on duodenal villus height, villus thickness, crypt depth, villus height/crypt depth ratio, and mucosal thickness; jejunal villus thickness and villus height/crypt depth ratio; and ilium villus thickness and crypt diameter (P<0.05), (Table 3). Also, the highest amount in most histological parameters was observed in 1% arginine treatment (Table 3). In a similar study, it was reported that in ovo injection of L- methionine had a positive impact on small intestine length and weight with improvement in villus height, crypt diameter, crypt depth, and villus height/crypt depth ratio of duodenum and jejunum (Fardoost et al. 2019). Also, in ovo injections of L- lysine improved histological parameters of duodenum, jejunum, and ileum (Ebrahimi et al. 2017). Ebrahimi et al. (2018b) with in ovo injection of different DL- methionine to L- lysine ratios reported higher small intestinal weight and length along with higher Villus height and Villus height to crypt depth ratio.

Based on the overall results of the study, injection of 0.5% arginine showed a positive effect on the growth and small intestine morphology of broiler chickens.

Previous studies have indicated the positive impact of dietary supplementation of arginine on meat quality and growth, though there is no report regarding the effect of in ovo injection of arginine on meat quality. So, the aim of this study was to evaluate the effect of in ovo injection of different levels of L-arginine on hatchability, growth performance, and meat quality of Ross 308 broiler chickens. In this research, 300 fertile eggs were used in a completely randomized design with three experimental treatments (levels of 0.5 and 1% of L- arginine and total control). Experimental groups included: 1) in ovo injection of 0.5% L-arginine, 2- in ovo injection of 1% L-arginine, 3) total control group {collected control 1 (injection of distilled water) and control 2 (no injection)}, which were injected on d 14 of incubation. After hatching, broiler chicks of arginine treatments and total control group were divided each into four equal groups and placed randomly into four cages (replicates of the experiment). The rearing period continued from hatching to d 24. In order to investigate the quality of meat, on day 24, three chicks from each replicate (12 chicks per each treatment) were weighed, slaughtered and their breast muscles were used for meat quality evaluation. Based on the results, in ovo injection of different levels of L- arginine did not significantly affect 1, 10 and 24 day-old birds’ weight, daily weight gain, feed intake, feed conversion ratio, and relative weight of scalped carcass and breast muscle (P >0.05). Although, meat pH, meat fat and Ash content, and meat color indexes (a*, b*, L*, H) were not affected by L- arginine in ovo injection treatments (P>0.05), meat water loss, ΔD, and C indexes were significantly affected by experimental treatments (P˂0.05). Based on the overall results of this study, in ovo injection with different levels of L- arginine could not have a significantly noticeable effect on growth performance, meat production and/or meat quality of 24 day- old broiler chickens.

In this study, 600 one-day Japanese quails were assigned to six treatments with five replicates of 20 chicks per replicate in 2×3 factorial arrangement based on a completely randomized experimental design. Two levels of L- arginine (the recommended level of NRC and 10% higher than the recommended level by NRC) and three levels of Guanidino acetic acid (GAA) (0, 0.6 and 1.2 g/kg diet) were used in this study. Body weight and feed intake were recorded at the end of the experiment. On day 42, blood samples from two chicks of each replicate were taken from wing vein for some blood metabolites measurements. Then, thechicks wereslaughtered for carcass and internal organs investigations. L-arginine supply at 10% over NRC recommendation increased daily feed intake, and improved body weight gain and feed conversion ratio significantly (P<0.05). L-arginine supply at 10% over NRC recommendation and 1.2 g GAA/kg diet increased feed intake and improved feed conversion ratio (P<0.05). The relative weight of breast and thigh increased and abdominal fat decreased significantly by L-arginine supplementation (P<0.05). The main effects of L- arginine and GAA on blood metabolites were significant (P<0.05), with a reduction effect on cholesterol, triglyceride and VLDL concentrations and enhancement effect on HDL content. L-arginine supply at 10% over NRC recommendation with 0.6 and 1.2 g GAA/kg diet significantly decreased blood cholesterol, triglyceride and VLDL and increased HDL concentrations in compared to those fed L- arginine at NRC recommendation (P<0.05). Therefore, the findings of this study showed that providing extra L- arginine than the NRC recommendation with 0.6 g GAA/kg diet significantly improved performance and decreased blood serum cholesterol, triglyceride, and VLDL in Japanese quails (P<0.05).