17 Determination of Various Dietary Levels of Inorganic Zinc onin Vitro Dry Matter Disappearance of Diets Fed to Cervids as Compared to Other Established Protocols

Abstract

Abstract The captive white-tailed deer breeding industry has an estimated economic impact of $1.6 billion, annually. However, nutritional requirements for cervids are determined through previous research based on sheep and goats. The objective of this study was to develop a methodology for harvesting rumen fluid from cervids for in vitro fermentation to analyze differences in dry matter disappearance with varying levels of supplemental zinc sulfate (ZnSO4). Rumen fluid was collected in conjunction with private hunts with partnership from a high fence producer. A European red hind (Cervus elaphus) and axis doe (Axis axis) were collected at separate times, each having a fermentation period utilizing the operating protocol for the Daisy incubator and A200 Fiber analyzer (Ankom Technology, Macedon, NY). The gastrointestinal tract was removed and tied at the terminal end of the esophagus and the beginning of the duodenum to prevent leakage. The tract was placed in a cooler with water at 39oC and transported to the laboratory in Huntsville, Texas. Each jar (3) served as an experimental unit, with Zn doses of 0.36, 3.6, and 36 g/d equivalents as treatments. Filter bags were filled with feed provided by the producer for the incubator prior to collection. Followed by Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) analysis with the fiber analyzer. The red deer NDF and ADF values ranged from 27.8% to 20.6% and 15.7% to 13.7% based on treatment, respectively. The axis NDF and ADF values ranged from 18.8% to 20.0% and 11.0% to 12.5% based on treatment, respectively. Previous in vitro digestibility studies conducted on sheep and cattle have produced similar NDF and ADF values with similar feed products. This preliminary study illustrated that the protocol is viable and will produce appropriate IVDMD results from NDF and ADF after in vitro rumination.