Effects Of Complexed Organic Trace Minerals On Lactation Performance,Antioxidant Capacity,Digestion And Metabolism,and Rumen Fermentation Function In Dairy Goats

Organic trace minerals have higher bioavailability.Using low-dose organic trace minerals instead of inorganic trace minerals can reduce the emission of trace minerals and reduce the impact on the environment under the condition of ensuring normal production performance and health.However,the effect of replacing inorganic trace minerals with low and medium dose organic trace minerals is inconsistent.Therefore,the purpose of this study is to apply low-dose organic trace element substitution scheme in the diet of lactating dairy goats,and provide reference data for the application of organic trace minerals in dairy goat breeding by evaluating the lactation performance,blood and milk trace element status,antioxidant capacity,digestion and metabolism,rumen fermentation function of dairy goats.Forty Xi’nong Saanen dairy goats(23.80 ± 3.41 d before delivery,body weight 71.55 ±1.32 kg)at the end of pregnancy were selected They were randomly divided into two groups:inorganic trace minerals group(ITM)and organic trace minerals group(OTM),with 20 goats in each group;in ITM group,inorganic trace minerals(sulfate form of iron,copper,zinc,manganese and sodium selenite)were used in the diet of dairy goats,with the addition level close to or slightly higher than NRC(2007)recommended nutritional requirements;in OTM group,organic trace minerals were used in the diet of dairy goats(The addition level of iron,copper,zinc,manganese and yeast selenium was 50% of that of ITM group.The experiment lasted from 3 weeks before delivery to the end of lactation.At the first,second,fourth and eighth lactation month,the feed intake,lactation performance,trace element status and antioxidant index of dairy goats were analyzed and determined;in addition,six experimental goats were randomly selected from ITM and OTM groups at the same time for digestion and metabolism test,and nutrient digestibility,trace element status in rumen fluid,rumen fermentation parameters,and the content of trace minerals in feces and urine were determined Excretion.The main results are as follows:1.The replacement of inorganic microelements with 50% inorganic microelements could not reduce the dry matter intake and lactation performance of lactating goats,improve the content of some microelements in blood and milk,increase the activities of T-AOC and GSH PX in serum of early lactation goats,and improve the antioxidant capacity of early lactation goats.2.The apparent digestibility of nutrients and the concentration of trace elements in urine of dairy goats will not be reduced by replacing inorganic trace elements with 50%inorganic trace elements.The higher digestibility of copper and selenium in some lactation stages of OTM group reduced the excretion of trace elements in feces and increased the deposition rate of trace elements.3.Replacing inorganic microelements with organic microelements at the level of 50%inorganic microelements did not affect the rumen fermentation function,only changed the concentration of Microelements in rumen fluid at the early lactation stage,and did not affect the concentration of Microelements in rumen fluid at other lactation stages.In conclusion,under the experimental conditions,the use of low-level organic trace elements instead of inorganic trace elements will not affect the normal production performance,nutrient digestion and metabolism and rumen fermentation function of lactating dairy goats,which can reduce the emission of trace elements in feces,indicating that organic trace elements have higher bioavailability.