In human nutrition dietary zinc, whose intake is often inadequate in elderly, may promote healthy aging. The aim of this study was to increase the milk zinc (Zn) content by dietary supplementation with organic zinc (zinc-methionine), also investigating the effect of such supplementation on milk yield and composition and milk and blood antioxidant status. In a 3 month study, 12 Simmenthal cows (4th month from parturition) were used to provide milk and blood samples. Animals were divided into 2 groups (CTL and Zn-Meth): control cows received a total mixed ratio (TMR) including 3 kg of commercial concentrate added with 330 mg inorganic Zn (Zn sulphate)/kg. Treated cows received the same TMR but commercial concentrate was added with 165 mg inorganic Zn (Zn sulphate) and 165 mg organic Zn (zn-methionine)/kg. Milk production was recorded every 2 weeks and individual milk and blood samples were collected and analysed for Zn concentration (ICP-MS) and redox status (colorimetric) by total antioxidant power (AOP) and reactive oxygen metabolites (ROMs) evaluation. ROMs were measured in blood serum, whereas milk samples were also analysed for total solids, protein, fat, ash content and AOP. Data were analysed by analysis of variance for repeated measures. Supplementation of 50% inorganic and 50% organic Zn did not affect the Zn concentration in milk (CTL 3240.4 vs Zn-Meth 3266.3 microg/L, SE=131.1) and blood serum (CTL 705.1 vs Zn-Meth 692.2 microg/L, SE=25.5). Milk yield and composition, serum ROMs (CTL 71.0 vs Zn-Meth 68.4 Carratelli Units, SE 2.7), and milk (CTL 146.1 vs Zn-Meth 141.8 micromol HClO/mL) and serum (CTL 431.1 vs Zn-Meth 444.0 micromol HClO/mL, SE=3.9) AOP, were not affected by the dietary treatment.
Effect of dietary organic zinc (Zn-Methionine) supplementation in dairy cows
FANTUZ, Francesco;BEGHELLI, Daniela;LEBBORONI, Gian Vincenzo;RENIERI, Carlo
2012-01-01
Abstract
In human nutrition dietary zinc, whose intake is often inadequate in elderly, may promote healthy aging. The aim of this study was to increase the milk zinc (Zn) content by dietary supplementation with organic zinc (zinc-methionine), also investigating the effect of such supplementation on milk yield and composition and milk and blood antioxidant status. In a 3 month study, 12 Simmenthal cows (4th month from parturition) were used to provide milk and blood samples. Animals were divided into 2 groups (CTL and Zn-Meth): control cows received a total mixed ratio (TMR) including 3 kg of commercial concentrate added with 330 mg inorganic Zn (Zn sulphate)/kg. Treated cows received the same TMR but commercial concentrate was added with 165 mg inorganic Zn (Zn sulphate) and 165 mg organic Zn (zn-methionine)/kg. Milk production was recorded every 2 weeks and individual milk and blood samples were collected and analysed for Zn concentration (ICP-MS) and redox status (colorimetric) by total antioxidant power (AOP) and reactive oxygen metabolites (ROMs) evaluation. ROMs were measured in blood serum, whereas milk samples were also analysed for total solids, protein, fat, ash content and AOP. Data were analysed by analysis of variance for repeated measures. Supplementation of 50% inorganic and 50% organic Zn did not affect the Zn concentration in milk (CTL 3240.4 vs Zn-Meth 3266.3 microg/L, SE=131.1) and blood serum (CTL 705.1 vs Zn-Meth 692.2 microg/L, SE=25.5). Milk yield and composition, serum ROMs (CTL 71.0 vs Zn-Meth 68.4 Carratelli Units, SE 2.7), and milk (CTL 146.1 vs Zn-Meth 141.8 micromol HClO/mL) and serum (CTL 431.1 vs Zn-Meth 444.0 micromol HClO/mL, SE=3.9) AOP, were not affected by the dietary treatment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
