Rob Bergsma

This study evaluated production traits, apparent total tract digestibility (ATTD), and fecal microbiota composition in finishing boars (n=207) selected for feed efficiency (FE; low = LFE; high = HFE) based on estimated breeding value for feed conversion ratio (FCR) within a Large White dam and sire genetic lines. Also, the association between gut m...

Background There is increasing interest in using intestinal organoids to study complex traits like feed efficiency (FE) and host-microbe interactions. The aim of this study was to investigate differences in the molecular phenotype of organoids derived from pigs divergent for FE as well as their responses to challenge with adherent and invasive Esch...

Providing pigs a diet that matches their nutrient requirements involves optimizing the diet based on the nutrient digestibility values of the considered feed ingredients. Feeding the same quantity of a diet to pigs with similar BW but with different requirements, however, can result in a different average daily gain (ADG) and backfat thickness (BF)...

The effects of birth weight (BiW) (low BiW (LBW) vs high BiW (HBW)) and estimated breeding value for protein deposition (EBV) (low EBV (LBV) vs high EBV (HBV)) on N retention, N efficiency and concentrations of metabolites in plasma and urine related to N efficiency in growing pigs were studied. At an age of 14 weeks, 10 LBW-LBV (BiW: 1.07 + 0.09 (...

Feature selection (FS, i.e., selection of a subset of predictor variables) is essential in high-dimensional datasets to prevent overfitting of prediction/classification models and reduce computation time and resources. In genomics, FS allows identifying relevant markers and designing low-density SNP chips to evaluate selection candidates. In this r...

This research assessed the ability of a Support Vector Machine (SVM) regression model to predict pig crossbred (CB) performance from various sources of phenotypic and genotypic information for improving crossbreeding performance at reduced genotyping cost. Data consisted of average daily gain (ADG) and residual feed intake (RFI) records and genotyp...

Feed efficiency (FE) is an important trait in livestock production. It is common to measure and improve FE via the feed conversion ratio (FCR), but the underlying biological mechanisms are still largely unknown and complex. Adult stem-cell derived organoids are powerful experimental models to study mammalian biology, and offer possibilities to adva...

Les mesures de l’ingéré sont les clés d’une sélection précise de l’efficacité alimentaire. Elles sont cependant coûteuses. De plus, ces performances dépendent de nombreuses composantes, telles que le niveau de production, l’activité et le comportement des animaux, leur aptitude à répondre à des stress, et leur capacité à digérer l’aliment. L’import...

With an increase in the number of animals genotyped there has been a shift from using pedigree relationship matrices (A) to genomic ones. As the use of genomic relationship matrices (G) has increased, new methods to build or approximate G have developed. We investigated whether the way variance components are estimated should reflect these changes....

Microbiota play an important role in total tract nutrient digestion, especially when fibrous diets are fed to pigs. This study aimed to use metagenomics to predict faecal nutrient digestibility in grower-finisher pigs. The study design consisted of 160 three-way crossbreed grower-finisher pigs (80 female and 80 male) which were either fed a diet ba...

In pig breeding, selection commonly takes place in purebred (PB) pigs raised mainly in temperate climates (TEMP) under optimal environmental conditions in nucleus farms. However, pork production typically makes use of crossbred (CB) animals raised in non-standardised commercial farms, which are located in TEMP but also in tropical and subtropical r...

Pig-breeding businesses have resulted in global breeding programs that select pigs to perform well on high-energy high-protein diets, which are traditionally based on corn and soybean meal. Nowadays, there is a shift toward diets based on cereals and co-products, therefore, high dietary inclusion of co-products can modify the expected performance o...

Improving feed efficiency is an important trait in livestock production. So far, feed conversion ratio (FCR) has been used to improve feed efficiency. However, the underlying biological mechanisms of feed efficiency are still not clear and very complex. Adult stem-cell derived organoids have already proven to be powerful experimental models of mamm...

Gut microbiota is a key contributor to feed use in monogastric species, in particular via the digestion dietary fibres. Molecular techniques are now available to run large studies and decipher the potential of gut microbiota to improve livestock. Studies on human and mice are more advanced: different factors have been demonstrated to influence the...

A major objective of pork producers is to reduce production cost. Feeding may account for over 75% of pork production costs. Thus, selecting pigs for feed efficiency (FE) traits is a priority in pig breeding programs. While in the Americas, pigs are typically fed high-input diets, based on corn and soybean meal (CS); in Western Europe, pigs are com...

Global pig breeding programmes that have a central breeding goal, do not necessarily select the best pigs for specific local circumstances if genotype by environment interaction (GxE) is present. There is evidence for GxE for feed efficiency (FE) traits. While in the Americas, pigs are typically fed high-input diets based on corn and soybean meal (...

The LocalPork project aims to improve the efficiency of pork production in Brazil. Pigs in Brazil are usually fed a diet based on corn and soybean. Growing these pigs on a diet that includes local alternative ingredients raises a number of questions related to breeding for such an environment. First, what is the economic and environmental impact of...

Dietary fiber content and composition affect microbial composition and activity in the gut, which in turn influence energetic contribution of fermentation products to the metabolic energy supply in pigs. This may affect feed efficiency (FE) in pigs. The present study investigated the relationship between the fecal microbial composition and FE in in...

Feed efficiency (FE) is an important trait in the pig industry, as feed costs are responsible for the major part of production costs. Availability in the market and cost of feed ingredients dictate changes in feed composition. As a result, fibre level and composition can vary between pig diets. Results of a retrospective study on digestibility tria...

Selection for feed efficiency (FE) is a strategy to reduce the production costs per unit of animal product, which is one of the major objectives of current animal breeding programs. In pig breeding, selection for FE and other traits traditionally takes place based on purebred pig (PB) performance at the nucleus level, while pork production typicall...

The LocalPork project aims to improve the efficiency of pork production in Brazil. Pigs in Brazil are usually fed a diet based on corn and soybean. Growing these pigs on a diet that includes local alternative ingredients raises a number of questions related to breeding for such an environment. First, what is the economic and environmental impact of...

Background Genomic prediction of purebred animals for crossbred performance can be based on a model that estimates effects of single nucleotide polymorphisms (SNPs) in purebreds on crossbred performance. For crossbred performance, SNP effects might be breed-specific due to differences between breeds in allele frequencies and linkage disequilibrium...

After publication of our article [1], we found a typo in the formula to build the genomic relationship matrix using allele frequencies across all genotyped pigs (matrix) and the genomic relationship matrix using breed-specific allele frequencies (matrix), and we noted that the description to this formula is not very clear.

Digestibility of nutrients in pig diets is an important component of overall feed efficiency. Targeted improvement of digestibility is currently mainly achieved by optimization of pig diets, based on information generated from digestibility trials that aim to establish fecal digestibility coefficients of different nutrients across a variety of ingr...

Feed efficiency (FE) is an important trait in the pig industry, as feed costs are responsible for the major part of production costs. Availability in the market and cost of feed ingredients dictate changes in feed composition. As a result, fibre level and composition can vary between pig diets. Microbiota in the gastrointestinal tract play an impor...

As feed costs continue to rise and efficiency during finishing is emphasized, the impact of selecting for more efficient grow/finish pigs on reproductive performance and feed efficiency of sows must be evaluated. Therefore, the objectives of this study were to evaluate correlated responses for sow reproductive performance and lactation feed efficie...

As feed costs continue to rise and efficiency during finishing is emphasized, the impact of selecting for more efficient grow/finish pigs on reproductive performance and feed efficiency of sows must be evaluated. Therefore, the objectives of this study were to evaluate correlated responses for sow reproductive performance and lactation feed efficie...

A total of 50 mixed parity sows of a high-prolificacy genetic line were used to evaluate the impact of feed restriction during lactation on their production and reproductive performance and their performance in the subsequent lactation. From day 7 of lactation, sows were distributed according to a completely randomized experimental design into two...

Genetic selection for increased litter size of sows increases the risk of a large negative energy balance during lactation. Furthermore, the feed intake capacity of the lactating sows might be reduced due to the simultaneous selection for higher feed efficiency during the growth phase when the sows were actually reared as finishers but later on sel...

This study examines the behavioral consequences of selecting pigs using a social genetic model for growth. Calculations enable each member of a group of pigs to be given a direct breeding value (DBV) and a social breeding value (SBV), which can be summarized into a total breeding value (TBV) for growth. Selection for growth TBV may have an impact o...

The aims of this study were, first, to evaluate the effects of climatic variables on daily feed intake of lactating sows and, second, to establish whether the response of sows to variation in temperature on feed intake during lactation was heritable. A total of 82,614 records for daily feed intake during lactation were available for 848 sows with 3...

The aim of this study was to investigate whether there is heritable social variation in ADG from birth until weaning in piglets. Nursing and the establishment of teat order are sources of social interaction among suckling piglets nursed by the same sow. If a heritable social effect is present, but ignored, the selected animals might be the most com...

Social interactions between individuals, such as co-operation and competition, are key factors in evolution by natural selection. As a consequence, evolutionary biologists have developed extensive theories to understand the consequences of social interactions for response to natural selection. Current genetic improvement programmes in animal husban...

Les interactions sociales entre porcs élevés dans une même loge affectent leurs performances. Nous avons estimé les conséquences génétiques sur le bien‐être d’une sélection pour la croissance en faveur des animaux ayant une meilleure performance propre et également un effet bénéfique sur la croissance de leurs partenaires de groupe. Dans un premier...

Les interactions sociales entre porcs élevés dans une même loge affectent leurs performances. Nous avons estimé les conséquences génétiques sur le bien‐être d’une sélection pour la croissance en faveur des animaux ayant une meilleure performance propre et également un effet bénéfique sur la croissance de leurs partenaires de groupe. Dans un premier...

Through genetic selection and improvement of environment, litter size of sows increases. Increased energy requirement during lactation, increases the risk of excessive mobilization from body stores, with detrimental effects on reproductive performance. Feed intake capacity tends to decrease due to selection towards leaner pigs with a lower feed con...

The increased productivity of sows increases the risk of a more pronounced negative energy balance during lactation. One possibility to prevent this is to increase the lactation efficiency (LE) genetically and thereby increase milk output for a given feed intake and mobilization of body tissue. The benefits of selection for LE depend on its heritab...

Social interactions among individuals are ubiquitous both in animals and in plants, and in natural as well as domestic populations. These interactions affect both the direction and the magnitude of responses to selection and are a key factor in evolutionary success of species and in the design of breeding schemes in agriculture. At present, however...

The possible consequences for aggressive behaviour and skin lesions from selecting pigs with a beneficial effect on the average daily gain (ADG) of penmates were assessed. Parameters for direct and group effects for ADG estimated previously on Dutch pigs were used to obtain estimated breeding values (EBV) for ADG in the study population (96 groups...

Intense aggression after mixing pigs is common and can affect performance and welfare. It also results in skin injuries which increase the risk of infection. Selective breeding on the group effect for average daily gain (ADG) (i.e. genetic potential of one individual to favour the growth of its pen-mates) could simultaneously increase the genetic...

The relationship between placental efficiency (PLEFF, i.e., the ratio of birth weight [BWB] to placental weight [PLW]) and neonatal pig vitality as measured by the probability of preweaning death of live born piglets was examined for 1,036 live born piglets of 118 litters. The data were first analyzed to establish whether the relationships between...