Nine young researchers in the spotlight

The 3rd annual meeting of Feed-a-Gene included oral presentations from young talented researchers whose work received funding by the H2020 programme.

Rapeseed meal and enzyme supplementation on growth performance and nutrient digestibility in pigs

Antonio Diego Brandao Melo (IRTA) antonio.brandao@irta.cat

The effects of high protein rapeseed meal (RSM) combined with enzyme (NSPase or protease) supplementation in 144 growing pig diets have been assessed during 6 weeks. It was shown that high protein RSM had no effect on body weight gain but reduced feed intake and thus improved feed conversion ratio. Fat digestibility was improved by RSM inclusion but DM, N or energy digestibilities were not affected by the diets. Enzymes combined to RSM had no further effect on pig production.

Development of models to predict the nutritional value of feedstuffs and feed mixtures by NIR

Samantha Joan Noel (Aarhus University) samantha.noel@anis.au.dk

NIR spectral scanning is a cheap and non-destructive way to predict feedstuffs composition provided it can be consistently calibrated with traditionally measured (chemical analysis) reference data. Over 1000 samples of individual feedstuffs and mixed diets were scanned and used to develop calibration models for 11 chemical, 18 amino acid, 10 mineral and 16 biological constituents. NIR predictions were tested with a reference group of samples that were not used to make the calibration models. Most of chemical and amino acid constituent models performed well while the mineral models performed poorly. Though the predictions for the biological constituents were slightly less accurate, they compared very well with the accuracy of the original in vivo data.

Relationship between microbiota composition and nutrient digestibility, effect of dietary fibers

Mathilde Le Sciellour (INRA UMR PEGASE) mathilde.lesciellour@inra.fr

In growing pigs fed on low or high fibre diets during 4 x 3-week-periods, digestibility measurements and faecal collections were done for RNA sequencing and subsequent microbiota characterization. It was possible to discriminate the 2 diets via 31 OTU’s. In pigs fed low fibre diets, Clostridiaceae and Turicibacter were negatively correlated to digestibility coefficients while Lactobacillus were positively correlated with protein digestibility and energy digestibility. In pigs fed high fibre diets, no correlation was found and it was not possible to quantitatively predict digestibility with microbiota information.

Short- and long-term effects of DON challenge on the performance and feeding behaviour of finishing pigs

Aira Maye Serviento (INRA) aira-maye.serviento@inra.fr

One of the most common mycotoxins in swine diets is deoxynivalenol (DON). It is thus important to evaluate the effects of DON challenge as a function of age on growth performance and feed efficiency in finishing pigs. DON challenge reduced feed intake by 25-30%, BW by 40-60% and feed efficiency by 20-34% in a study conducted on 160 pigs. The severity of DON effects depends on the age of the pigs and of the number of challenges occurring: though pigs can recover to some extent, in all cases DON is deleterious to the final weight.

Plasma metabolites related to nitrogen efficiency in grower-finisher pigs

Lisanne Verschuren (Topigs Norsvin) lisanne.verschuren@topigsnorsvin.com

Untargeted metabolomics were used to study the effect of birth weight (low or high BthW) on N metabolism of pigs receiving adequate (100%) protein or restricted (70%) protein diets during the growing-finishing stage. Plasma metabolites differed between the BthW groups and diets. The metabolites indicating the effects of protein restriction were different between pigs of different BthW and could be the result of differences in N metabolism in pigs of different BthW.

On the use of voluntary feed intake for automatic detection and characterization of the response of growing pigs to perturbations

Hieu Nguyen Ba (INRA UMR PEGASE) hieu.nguyen-ba@inra.fr

Hypothesizing there is an ideal trajectory of cumulative feed intake in growing pigs, data of feed intake were analysed and compared to the ideal trajectory. It was then possible to develop a generic model of feed intake based on differential equation where deviations from the ideal trajectory of cumulative feed intake reveal periods of perturbation characterized by duration and magnitude. The equation could be characterized by 2 parameters: a first one describes the reduction in daily feed intake and corresponds to resistance to a perturbation (i.e. a “resistance” trait) and the second one describes the capacity of the animal to adapt and recover ideal trajectory (i. e. a “resilience” trait). In this model, cumulative feed intake is a valuable proxy for complex and difficult to measure robustness trait (i.e. resistance + resilience traits).

Application of a pig model to predict broiler performance

Galyna Dukhta (Kaposvar University) galyna.dukhta@ke.hu

Starting from InraPorc model of growth, it was proposed to adapt it to a poultry growth model including 3 submodules:

• a metabolic module which simulates energy and protein partitioning in broilers and individual daily growth performance under ideal conditions,
• a P and Ca module that predicts digestible P and Ca utilization and thus P load of broiler production,
• and a feed intake module that takes environmental conditions into account and modifies actual energy intake as a response to undesired heat losses.

Precision feeding development for lactating sows: nutritional requirements modelling

Raphaël Gauthier (INRA) raphael.gauthier@inra.fr

The InraPorc growth model was used to develop a decision support tool for the precision feeding of lactating sows which are often under-optimally fed. Acquiring data on sows and their environment at high-throughput allowed to determine the optimal supply for each animal. In sows fed in excess, it was possible to reduce average digestible lysine excess by 81%, and, in deficient sows, it was possible to reduce deficiency by 63%. Precision feeding also reduced lysine and P intake and limited the occurrence of excess and deficiency.

Genetics component of feed efficiency in layers using DNA-seq and RNA-seq: preliminary results

Frédéric Jehl (INRA) frederic.jehl@inra.fr

DNA and multi-tissue (fat, blood, hypothalamus and liver) RNA sequencing were used to characterize lines of laying hens diverging for feed efficiency. DNA sequencing found 143,965 bi-allelic SNPs (single nucleotide polymorphism) for which one allele is homozygous in one line and heterozygous in the other line. 4 SNPs were predicted to lead to a premature stop codon and could have a role in the difference of feed efficiency. 98% of the SNPs were out of the coding region. RNA sequencing revealed that, depending on the tissue, 2996 to 6826 genes were differently expressed in the 2 lines. Pathways associated with the coding genes remain to be studied.