Grassland-based beef production: a case study on the economic impact and ecosystem services in a Limousin cattle farm

This case study assessed the economic impact of grassland-based beef production and associated ecosystem services in a commercial Limousin cattle farm. It aimed to determine (1) the technical and economic performances of different fodder crops including permanent and temporary grasslands, (2) how grazed grass and self-produced fodders are utilised by young bulls and heifers, and (3) associated ecosystem services including carbon fixation of permanent grassland soils and beef meat quality produced from grass. Data were collected from 2013 to 2015. Dry matter yield, nutritional value and cost price were determined for each fodder crop. Animals were weighed every three weeks. In 2015, meat samples from seven bulls finished on pasture were analysed for fatty acids composition. Average daily gains ranged from 1.29 kg day-1 in 2015 to 1.35 in 2014 for young bulls grown on grazed grass without supplementation. Grassland soil carbon content linearly increased with grassland age. The meat polyunsaturated fatty acids content increased with grazing duration. In conclusion, this study showed that grassland allows an increase in both the economic and environmental sustainability of beef production systems but also offers nutritional health benefits to the consumer

Qualité technologique du blé dur BIO 2023

Blé dur bio, leviers pour améliorer sa teneur en protéine: fumure azotée, choix variétal et autres facteurs (année, climat, sol, précédent ...

Effect of manipulating recombination rates on response to selection in livestock breeding programs

International audienceBackgroundIn this work, we performed simulations to explore the potential of manipulating recombination rates to increase response to selection in livestock breeding programs.MethodsWe carried out ten replicates of several scenarios that followed a common overall structure but differed in the average rate of recombination along the genome (expressed as the length of a chromosome in Morgan), the genetic architecture of the trait under selection, and the selection intensity under truncation selection (expressed as the proportion of males selected). Recombination rates were defined by simulating nine different chromosome lengths: 0.10, 0.25, 0.50, 1, 2, 5, 10, 15 and 20 Morgan, respectively. One Morgan was considered to be the typical chromosome length for current livestock species. The genetic architecture was defined by the number of quantitative trait variants (QTV) that affected the trait under selection. Either a large (10,000) or a small (1000 or 500) number of QTV was simulated. Finally, the proportions of males selected under truncation selection as sires for the next generation were equal to 1.2, 2.4, 5, or 10 %.ResultsIncreasing recombination rate increased the overall response to selection and decreased the loss of genetic variance. The difference in cumulative response between low and high recombination rates increased over generations. At low recombination rates, cumulative response to selection tended to asymptote sooner and the genetic variance was completely eroded. If the trait under selection was affected by few QTV, differences between low and high recombination rates still existed, but the selection limit was reached at all rates of recombination.ConclusionsHigher recombination rates can enhance the efficiency of breeding programs to turn genetic variation into response to selection. However, to increase response to selection significantly, the recombination rate would need to be increased 10- or 20-fold. The biological feasibility and consequences of such large increases in recombination rates are unknown

Joint technical and economic assessment of feed autonomy in organic cattle farms

Increasing the level of feed autonomy (self-sufficiency) is usually considered as a prerequisite for conversion of cattle farms to organic farming. Technically it requires adjusting fodder production and feed purchases in terms of quantity and quality to the requirements of the herd. A joint technical and economic assessment of feed autonomy in organic cattle farms was conducted. Data were collected in 2014 and 2015 on 11 Belgian farms located in distinct agricultural regions and characterised by different proportions of grassland area. Dry matter yield and nutritional quality were determined at each harvest for each fodder crop, including permanent and temporary grasslands, immature cereal-legume crops and grain crops. Animal productions and economic data, including all cash inflows and outflows, were recorded. Economically efficient farms had high levels of feed autonomy, ranging from 89 to 100%. Three economically-efficient feeding strategies were identified for organic cattle production. Strategies differed from each other according to the proportion of grassland area, level of animal production and the achieved level of feed autonomy

Parasitisme chez les génisses au pâturage en relation avec les pratiques des éleveurs en agriculture biologique

La gestion du parasitisme au pâturage est un défi majeur pour l’éleveur, particulièrement en conditions bio. Par ailleurs, une exposition contrôlée contribue à construire une immunité tout en ayant un impact limité sur les performances animales.→ Objectifs: (i) déterminer les relations entre pression parasitaire et pratiques des éleveurs dans des fermes bovines bio(ii) identifier des pratiques à recommander aux éleveur

Variétés de froment en agriculture biologique

Le "Livre Blanc" est un collectif regroupant des chercheurs des deux grandes institutions gembloutoises de recherche agronomique (Centre wallon de Recherches agronomiques et Faculté Universitaire des Sciences Agronomiques), visant à la vulgarisation directe et rapide des résultats de la recherche sur les céréales à destination des agriculteurs. Cette vulgarisation se traduit chaque année par deux grandes journées de conférences sur les céréales, et par deux éditions du Livre Blanc: l'édition de septembre pour les conseils de semis et l'édition de février pour le bilan à mi-saison et les conseils sortie hiver

AlphaSim: Software for Breeding Program Simulation

This paper describes AlphaSim, a software package for simulating plant and animal breeding programs. AlphaSim enables the simulation of multiple aspects of breeding programs with a high degree of flexibility. AlphaSim simulates breeding programs in a series of steps: (i) simulate haplotype sequences and pedigree; (ii) drop haplotypes into the base generation of the pedigree and select single-nucleotide polymorphism (SNP) and quantitative trait nucleotide (QTN); (iii) assign QTN effects, calculate genetic values, and simulate phenotypes; (iv) drop haplotypes into the burn-in generations; and (v) perform selection and simulate new generations. The program is flexible in terms of historical population structure and diversity, recent pedigree structure, trait architecture, and selection strategy. It integrates biotechnologies such as doubled-haploids (DHs) and gene editing and allows the user to simulate multiple traits and multiple environments, specify recombination hot spots and cold spots, specify gene jungles and deserts, perform genomic predictions, and apply optimal contribution selection. AlphaSim also includes restart functionalities, which increase its flexibility by allowing the simulation process to be paused so that the parameters can be changed or to import an externally created pedigree, trial design, or results of an analysis of previously simulated data. By combining the options, a user can simulate simple or complex breeding programs with several generations, variable population structures and variable breeding decisions over time. In conclusion, AlphaSim is a flexible and computationally efficient software package to simulate biotechnology enhanced breeding programs with the aim of performing rapid, low-cost, and objective in silico comparison of breeding technologies

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Le blé dur

Création, caractéristiques du blé dur et fertilisation azoté

Quantitative approach of the genetic determinism of sex expression in monoecious hemp (Cannabis sativa L.), and its relationship with flowering phenology and stem and seed yields

The sex expression is a major concern for the genetic improvement of hemp. Although naturally dioecious and bearing heteromorphic sex chromosomes, the species displays a highly variable sexual phenotype. The monoecious cultivars allow the mechanical harvest of both stem and seed; however, their seed production requires a strict control of the sex expression. This thesis investigated the genetic determinism of sex expression in monoecious hemp and established its relationship with flowering phenology and stem and seed yields. The existence of genotypic variability for the sex expression in monoecious hemp was evidenced despite the high environmental sensitivity of the trait. Sex expression and earliness varied mostly consistently among cultivars. Higher seed yields were associated with (mid-) early feminised cultivars. Monoecious hemp was demonstrated to bear XX chromosomes, which showed homologies with both the X and Y ones of dioecious hemp. Three F1 segregating populations were created, and genetic maps were constructed. The distribution of male and female flowers in monoecious plants was modelled. A relatively high number of genomic regions (QTLs) showed variation associated with the model parameters. Some of them were likely located on the sex chromosomes. Closely linked QTLs for sex expression, earliness and yields were found. Their putative implications for breeding were discussed. In conclusion, the present quantitative approach successfully provided fundamental insights to improve our understanding of the genetic determinism of sex expression in monoecious hemp and to support its cultivation for a dual production.(AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 201