Hassan Shirzadi; Zaynab Nazari; Kamran Taherpour
Volume 22, Issue 1 , March 2020, , Pages 153-164
Abstract
The current study was conducted to evaluate the efficacy of Thymbra spicata (TS) and Echinacea purpurea (EP) powders on quality of breast muscle in broiler chickens exposed to Campylobacter jejuni. A total of 192 one-d-old straight-run broiler chicks (Ross 308) were randomly allocated to 6 dietary ...
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The current study was conducted to evaluate the efficacy of Thymbra spicata (TS) and Echinacea purpurea (EP) powders on quality of breast muscle in broiler chickens exposed to Campylobacter jejuni. A total of 192 one-d-old straight-run broiler chicks (Ross 308) were randomly allocated to 6 dietary treatments in a completely randomized design with 4 replicates and 8 birds per each. The experimental diets were as follows: 1) basal diet without additive (control group); 2,3) basal diet supplemented with EP powder (0.25 and 0.50%; EP-0.25 and EP-0.50); 4,5) basal diet supplemented with TS powder (0.25 and 0.50%; TS-0.25 and TS-0.50), and 6) basal diet supplemented with Erythromycin (55 ppm). All of the broiler chicks were orally gavaged with Campylobacter jejuni (4×1011 cfu/mL) on d 21. Malondialdehyde concentration in breast muscle was significantly decreased by supplementing diets with EP-0.25, TS-0.25, and erythromycin (P<0.05). All experimental treatments also resulted in a significant decrease in the colonization of psychrophilic bacteria in breast muscle when compared with the control group (P<0.05), however, aerobic bacteria count was significantly decreased only by TS-0.25 and erythromycin (P<0.05). Other traits such as pH, color, chemical composition, water holding capacity, drip loss, cooking loss, and press loss were not significantly affected by treatments. As a conclusion, for the prevention of lipids peroxidation and the decline of psychrophilic bacteria count, it could be advised to use EP and TS with 0.25% diet instead of erythromycin, however, TS is preferable to EP, because of the higher antibacterial activity on reduction of aerobic bacteria count.
Masomeh Nasiroleslami; Mehran Torki; Alireza Abdolmohammadi
Volume 20, Issue 1 , May 2018, , Pages 95-108
Abstract
This study was conducted to determine the effects of dietary supplemental guanidinoacetic acid and betaine on performance, carcass characteristics, meat quality and thyroid hormones of broilers subjected to cold stress. Based on a 2×2 factorial arrangement, 384 day-old male broiler chicks (Cobb) ...
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This study was conducted to determine the effects of dietary supplemental guanidinoacetic acid and betaine on performance, carcass characteristics, meat quality and thyroid hormones of broilers subjected to cold stress. Based on a 2×2 factorial arrangement, 384 day-old male broiler chicks (Cobb) were randomly distributed between four experimental diets (with eight replicates) included basal diet (as control) and the basal diet supplemented with 1200 mg/kg guanidinoacetic acid; 600 mg/kg betaine and 1200 mg/kg guanidinoacetic acid + 600 mg/kg betaine. This trial was performed at the Animal Farm of Razi University (March 2015). In order to create cold stress, on 21th day all birds were subjected to a low temperature (12-15°C), which was remained constant until the end of the experiment. There was no significant effect of experimental diets on the chick’s performance, carcass characteristics, thyroid hormones and liver glycogen levels. Increased breast meat was observed in birds fed the guanidinoacetic acid-included diet. Significant increased L* and a* of meat color were detected in birds fed diets supplemented with guanidinoacetic acid and betaine. Decreased crud fat percentage of breast meat was detected in birds fed the betaine-included diet. The meat pH decreased by time. Increased meat pH was observed in birds fed the betaine-included diet. In conclusion, improved yield and decreased crud fat percentage of breast meat were observed in birds fed the guanidinoacetic acid- and betaine-included diets, respectively. Color indices of broiler breast meat was improved by diet supplementation with guanidinoacetic acid and betaine.