Comparison of the efficacy of macrocyclic lactone anthelmintics,either singly or in combination with other anthelmintic(s), in nine beef herds in southern NSW

Anthelmintic resistance (AR) is a well-recognized challenge in farmed ruminants. The use of anthelmintics in combination is one of the strategies recommended to slow the rate of AR development. Two studies were undertaken in 2017 and 2019 to assess the efficacy of single-dose macrocyclic lactone (ML) anthelmintic and ML combination drenches. In total, 11 Faecal Egg Count Reduction Trials (FECRTs) were set up in 10 different beef herds, with results available from 10 of those FECRTs (9 herds). AR to a single ML anthelmintic was detected in all 9 herds, with resistance to Cooperia and Haemonchus spp on 9 farms, and resistance to Ostertagia and Trichostrongylus spp on 2 farms. In contrast, for the ML combination anthelmintics, all FECRTs resulted in efficacies of 99%–100%. The results suggest that cattle producers should strongly consider using combination drenches in their herds in preference to single actives.     

Development of Standard Procedures for a Simple,Rapid Test to Determine Wheat Color Class

Growing conditions, kernel characteristics, and genetics affect wheat kernel color. As a result, red and white wheats sometimes cannot be differentiated by visual examination. Soaking wheat kernels in a sodium hydroxide solution enhances the difference in color; red wheat turns a darker red, and white wheat turns straw‐yellow. Previously, when NaOH was used for wheat determination of color class, only a visual assessment was made under arbitrary conditions, many times not suitable for field work. In the present work, visible reflectance spectroscopy and visual assessments were used to optimize NaOH (2 mL/g of wheat) soak time (10 min), concentration (5M or 20%), and temperature (60°C). The optimal procedure will provide users who are not laboratory trained with inexpensive, safe procedures to definitively assign wheat color class in the shortest time in field locations. Calibration and prediction of several wheat cultivars using partial least square regression were used to validate the optimal test procedure. The test differentiated even rain‐bleached wheat and cultivars that were difficult to classify visually. No distinct correlation occurred between predicted color value and the number of red genes.     

Invisible Coatings for Wheat Kernels

It is occasionally necessary to tag wheat kernels without altering their appearance. Coatings have potential applications to tag wheat of a particular color or protein class, diseased wheat such as Karnal bunt, or genetically modified wheat. This methodology will aid in development of calibrations for sorting instruments. Procedures were developed to coat wheat kernels with invisible ultraviolet (UV) fluorescent and near‐infrared (NIR) absorbing noncarcinogenic dyes. Wheat coated with UV‐fluorescent compounds were identified under black light. The NIR‐absorbing coating required lower concentrations of dye than the UV dyes and wheat coated with NIR‐absorbing dye were identified from their NIR spectrum.     

Molecular Weight Distribution of Proteins in Hard Red Spring Wheat: Relationship to Quality Parameters and Intrasample Uniformity

Molecular weight distribution (MWD) of proteins extracted from hard red spring wheat was analyzed by size‐exclusion HPLC to investigate associations with wheat and breadmaking quality characteristics. Certain protein fractions were related to associations between wheat and breadmaking parameters, specifically when effect of quantitative variation of protein on those parameters was statistically eliminated by partial correlation analysis. SDS‐unextractable high molecular weight polymeric proteins had positive partial correlations with percent vitreous kernel content and breadmaking parameters, including mix time and bread loaf volume. SDS‐extractable protein fractions that were eluted before the primary gliadin peak had positive partial correlations with kernel hardness and water absorption parameters. The proportion of main gliadin fractions in total protein had a negative partial correlation with bread loaf volume and positive correlations with kernel hardness and water absorption parameters. Intrasample uniformity in protein MWD and kernel characteristics was estimated from three kernel subsamples that were separated according to single kernel protein content within individual wheat samples by a single‐kernel near‐infrared sorter. Wheat subsamples were significantly different in protein MWD. Intrasample uniformity in protein MWD did not differ greatly among wheat samples.