A general algorithm to compute multilocus genotype frequencies under various mating systems

International audienc

A new infrared spectroscopy sample presentation unit for measuring feeding quality of maize stover

Maize stover is used to feed farm animals and the improvement of its quality is an important breeding goal. The main objective of our study was to evaluate a new near infrared (NIR) spectroscopy sample presentation unit for measuring feed quality of maize stover. In this context, we investigated the effect of engineering factors (use of glass interface and packing pressure) on the spectral repeatability and the effect of particle sizes (8 cm, 6 cm, 4 cm, 0.5 cm) on the calibration performance. The spectral repeatability was examined by calculating spectral variation among replicated spectral measurements collected without glass interface, with glass interface, and glass interface in combination with 3 kg and 6 kg of packing pressure. The effect of particle sizes was assessed for concentrations of nitrogen (N), neutral detergent fibre (NDF), ash and in vitro fermentability (G24), by examining calibration models. The spectral repeatability increased with the use of glass interface and packing pressure and calibration performance improved with a reduction in particle size. The study indicated that the new NIR sample presentation unit has a potential for preliminary screenings of maize genotypes for NDF and G24 in the stover of particular breeding programmes

Feeding quality assessment of fresh maize stover by means of near-infrared spectroscopy with a new sample presentation unit

Stover quality traits are important in breeding programmes of maize cultivars. However, conventional procedures for evaluation of stover quality are expensive and thus limit the full exploitation of the available genetic variability. Our objective was to assess the potential of near-infrared spectroscopy (NIRS) with a new sample presentation unit to determine feeding quality of maize stover. The plant material comprised maize inbreds and hybrids. The sample presentation unit was equipped with a near-infrared diode-array spectrometer. Coefficient of determination in cross-validation ranged between 0.77 and 0.94 for contents of dry matter, nitrogen, neutral detergent fibre and in vitro fermentability expressed as gas volume after 24h incubation time, but it was lower for ash content. It was concluded that NIRS with the new sample presentation unit was less accurate than laboratory NIRS to predict the standard reference methods. However, the new sample presentation unit might be used as a fast and efficient technique to perform large screenings of maize stover accessions in breeding programmes

Feeding quality assessment of fresh maize stover by means of near-infrared spectroscopy with a new sample presentation unit

Stover quality traits are important in breeding programmes of maize cultivars. However, conventional procedures for evaluation of stover quality are expensive and thus limit the full exploitation of the available genetic variability. Our objective was to assess the potential of near-infrared spectroscopy (NIRS) with a new sample presentation unit to determine feeding quality of maize stover. The plant material comprised maize inbreds and hybrids. The sample presentation unit was equipped with a near-infrared diode-array spectrometer. Coefficient of determination in cross-validation ranged between 0.77 and 0.94 for contents of dry matter, nitrogen, neutral detergent fibre and in vitro fermentability expressed as gas volume after 24h incubation time, but it was lower for ash content. It was concluded that NIRS with the new sample presentation unit was less accurate than laboratory NIRS to predict the standard reference methods. However, the new sample presentation unit might be used as a fast and efficient technique to perform large screenings of maize stover accessions in breeding programmes