Repeatability and reproducibility of the Cornell Net Carbohydrate and Protein System analytical determinations

In Vitro Techniques Using the DaisyII Incubator for the Assessment of Digestibility: A Review

Simple Summary

The Ankom Daisy^II incubator (AD^II; Ankom Technology Corporation Fairport, NY, USA) has gained acceptance as an alternative to traditional in vitro procedures. It reduces the labour requirement and increases the number of determinations that can be completed by a single operator. The apparatus allows for the simultaneous incubation of several feedstuffs in sealed polyester bags in the same incubation vessel, which is rotated continuously at 39.5 °C. With this method, the material that disappears from the bag during incubation is considered digestible. The method, which was first developed to predict the digestibility of feedstuffs for ruminants, has been modified and adapted to improve its accuracy and prediction capacity. Modifications used by various researchers include the use of different inocula, buffer solutions, and sample weights. Recently, attempts have been made to adapt the method to determine nutrient digestibility of feedstuff in non-ruminant animals, including pets.

Abstract

This review summarises the use of the Ankom Daisy^II incubator (AD^II; Ankom Technology Corporation Fairport, NY, USA), as presented in studies on digestibility, and its extension to other species apart from ruminants, from its introduction until today. This technique has been modified and adapted to allow for different types of investigations to be conducted. Researchers have studied and tested different procedures, and the main sources of variation have been found to be: the inoculum source, sample size, sample preparation, and bag type. In vitro digestibility methods, applied to the AD^II incubator, have been reviewed, the precision and accuracy of the method using the AD^II incubator have been dealt with, and comparisons with other methods have been made. Moreover, some hypotheses on the possible evolutions of this technology in non-ruminants, including pets, have been described. To date, there are no standardised protocols for the collection, storage, and transportation of rumen fluid or faeces. There is also still a need to standardise the procedures for washing the bags after digestion. Moreover, some performance metrics of the instrument (such as the reliability of the rotation mechanism of the jars) still require improvement.

Proficiency Testing of Feed Constituents: A Comparative Evaluation of European and Developing Country Laboratories and Its Implications for Animal Production

Proficiency tests, with two feed samples each year, for various constituents (proximate, macro- and microminerals, feed additives, and amino acids) were conducted in 2014 and 2015. A total of 40 and 50 European and 73 and 63 developing country feed analysis laboratories participated in the study in 2014 and 2015, respectively. The data obtained from these two sets of laboratories in each year enabled a comparison of the performance of the European and developing country laboratories. Higher standard deviation and several-fold higher coefficients of variation were obtained for the developing country laboratories. The coefficients of variation for chemical composition parameters, macrominerals, microminerals, and amino acids were higher by up to 9-fold, 14-fold, 10-fold, and 14-fold, respectively, for the developing country laboratories compared with the European laboratories in 2014, while the corresponding values for 2015 were 4.6-fold, 4.4-fold, 9-fold, and 14-fold higher for developing county laboratories. Also, higher numbers of outliers were observed for developing countries (2014, 7.6-8.7% vs 2.9-3.0%; 2015, 7.7-9.5% vs 4.2-7.0%). The results suggest higher need for developing country feed analysis laboratories to improve the quality of data being generated. The likely impact of higher variability of the data generated in developing countries toward safe and quality preparation of animal diets, their impact on animal productivity, and possible ways to improve the quality of data from developing countries are discussed.