Effect of dietary supplementation of organic or inorganic zinc on carbonic anhydrase activity in eggshell formation and quality of aged laying hens

Abstract

This study evaluated the effects of different dietary levels and sources of zinc (Zn) on performance and carbonic anhydrase (CA) activity in eggshell formation and quality in aged laying hens. A total of 504 Hy-line Grey layers aged 59 wk were fed a basal diet (Zn, 28.4 mg/kg) for 4 wks, then randomly allocated to 7 groups that were fed a basal diet or a basal diet supplemented with inorganic (ZnSO4·H2O) or organic (amino acid metals, 9.58%) Zn at 35, 70, or 140 mg Zn per kg of feed for 6 weeks. Each group had 6 replicates of 12 hens. Results showed that egg weight decreased linearly with the supplemental level of organic Zn (P < 0.05). Dietary Zn supplementation had linear and quadratic effects on the CA activity in plasma (P < 0.05), and it was higher in the organic Zn-added groups at wks 2 and 4 (P < 0.05). Dietary Zn supplementation had a quadratic effect on the CA activity in the eggshell gland (P < 0.05). Shell thickness was greater in the organic Zn-added groups (P < 0.05), and its relationship with the supplemental level of Zn showed linearly and quadratically, increasing with the organic Zn and with the inorganic Zn at wk 4, while linearly increasing with the inorganic Zn at wk 6 (P < 0.05). At wk 4, the supplemental level of inorganic Zn had a linear effect on shell weight, and linear and quadratic effects on shell index and ratio (P < 0.05), while shell weight, the index, and ratio increased linearly and quadratically with the organic Zn level in the diet (P < 0.05), with more obvious effects in the organic Zn-added groups (P < 0.05). Overall, dietary Zn supplementation, up to 140 mg/kg feed, could increase eggshell thickness by enhancing CA activity in the plasma and eggshell gland of aged layers; thicker eggshells were found in the organic Zn-added groups, but the breaking strength did not increase despite the eggshell thickness increasing.

Effects of nanoparticles of zinc oxide on productive performance of laying hens. – a review.

“…Mao and Lien (2017) supplementation of laying hens diets with 80 mg/kg Nano-ZnO had no beneficial influence on FCR. Zhang et al (2017) found that FCR was not affected in Hy-line layers consuming 35, 70, or 140 mg organic or inorganic zinc per kg diet compared to the control group. In addition to, Yıldırım (2017) added 20, 40, 60, 80 and 100 mg Nano-ZnO /kg diet of Super Nick laying hens observed that FCR was non (P>0.05) differences between treatment groups.…”

“…Likewise, Badawi et al (2017) reported that feed intake of broiler chickens was not significantly affected by supplementation of 40 ppm Nano-ZnO /kg. Also, Zhang et al (2017) found that the average daily feed intake was not affected in Hy-line layers fed diet supplemented with 35, 70, or 140 mg organic or inorganic zinc per kg diet compared to the control group. Yıldırım (2017) observed that supplementation of 20, 40, 60, 80 and 100 mg Nano-ZnO /kg to super Nick laying hens did not affect the feed intake.…”

“…Mao and Lien (2017) found that basal diet supplemented with 80 mg Nano-ZnO/kg had not affect egg production of laying hens. Moreover, Zhang et al (2017) found that the egg production was not affected in Hy-line layers fed diet supplemented with 35, 70, or 140 mg organic or inorganic zinc per kg diet compared to the control group. Also, Yıldırım (2017) reported that egg production was not significantly affected by supplemenation of 20, 40, 60, 80 and 100 mg Nano-ZnO /kg diet of Super Nick laying hens.…”

“…Same result was observed by Mao and Lien (2017) found that addition of laying hens diets with 80 mg/kg nano zinc had no significant influence on egg weight. Moreover, Zhang et al (2017) noted that egg weight was not affected in Hy-line layers fed diet with 35, 70, or 140 mg organic or inorganic zinc per kg diet compared to the control group. Abedini et al (2017) reported that supplementation of 80 mg Nano-ZnO/kg to laying hens had not affect the egg weight.…”

Copper and zinc sources and levels of zinc inclusion influence growth performance, tissue trace mineral content, and carcass yield of broiler chickens

“…Copper plays critical roles as a co-factor in many enzymes (Davis and Mertz, 1987) relevant to maintaining proper body functions. Because of its many roles, Zn is vitally important in supporting bone and tissue development (Sahraei et al, 2012), egg shell quality (Zhang et al, 2017), as well as in proper functioning of the immune system (Feng et al, 2009; Jarosz et al, 2017; Perez et al, 2017). In pigs, Zn has been reported to help alleviate post-weaning diarrhea (Zhang and Guo, 2009) and high levels of the Zn and Cu have pharmacological relevance in the swine and poultry industries (Pettigrew, 2006; Zhang and Guo, 2007).…”