Genetic selection for nonstructural carbohydrates and its impact on other nutritive attributes of alfalfa (Medicago sativa) forage

Abstract

High concentration of nonstructural carbohydrates (NSC) in forages improves ruminant N utilization and performance. The present study evaluated the direct and indirect effects of one cycle of divergent phenotypic selection for NSC in alfalfa along with the diurnal and seasonal stability of the trait. For this purpose, divergent NSC populations were developed (NSC+ and NSC−) and two field trials were established in Quebec, Canada. Forage samples were collected twice a day (morning and afternoon) and three times a year (spring, summer and autumn) and analysed for NSC, crude protein (CP), fibre concentration, digestibility and yield. The NSC+ population maintained greater NSC concentrations than the NSC− population over 2 establishment years (+18%, 129 vs. 109 g/kg) and three production years (+8%, 126 vs. 116 g/kg). Time of cutting and period of harvest had significant effects on alfalfa NSC concentration and other nutritive attributes, but they did not affect the response to selection for NSC concentration. Phenotypic selection for NSC concentration can therefore be used in a recurrent phenotypic selection approach to improve alfalfa nutritive value.

Agrotechnology for Feed Cultivation and Creation of Hayfields and Pastures in the Forest and Steppe Zone of Northern Kazakhstan

“…Feed harvesting mainly depends on the external parameters of crop development (Ta et al, 2020). In the flowering phase of feed crops, the first cutting as a relative indicator best defines as follows: it is better to cut the green mass at the beginning of flowering based on the nutritional value, fermentation characteristics, and digestibility of feed in the rumen of animals (Guo et al, 2019;Claessens et al, 2021).…”