Effect of a probiotic and an antibiotic on the mobilome of the porcine microbiota

Introduction: To consider the growing health issues caused by antibiotic resistance from a "one health" perspective, the contribution of meat production needs to be addressed. While antibiotic resistance is naturally present in microbial communities, the treatment of farm animals with antibiotics causes an increase in antibiotic resistance genes (ARG) in the gut microbiome. Pigs are among the most prevalent animals in agriculture; therefore, reducing the prevalence of antibiotic-resistant bacteria in the pig gut microbiome could reduce the spread of antibiotic resistance. Probiotics are often studied as a way to modulate the microbiome and are, therefore, an interesting way to potentially decrease antibiotic resistance. Methods: To assess the efficacy of a probiotic to reduce the prevalence of ARGs in the pig microbiome, six pigs received either treatment with antibiotics (tylvalosin), probiotics (Pediococcus acidilactici MA18/5M; Biopower® PA), or a combination of both. Their faeces and ileal digesta were collected and DNA was extracted for whole genome shotgun sequencing. The reads were compared with taxonomy and ARG databases to identify the taxa and resistance genes in the samples. Results: The results showed that the ARG profiles in the faeces of the antibiotic and combination treatments were similar, and both were different from the profiles of the probiotic treatment (p < 0.05). The effects of the treatments were different in the digesta and faeces. Many macrolide resistance genes were detected in a higher proportion in the microbiome of the pigs treated with antibiotics or the combination of probiotics and antibiotics. Resistance-carrying conjugative plasmids and horizontal transfer genes were also amplified in faeces samples for the antibiotic and combined treatments. There was no effect of treatment on the short chain fatty acid content in the digesta or the faeces. Conclusion: There is no positive effect of adding probiotics to an antibiotic treatment when these treatments are administered simultaneously.

Impact of deoxynivalenol in a calcium depletion and repletion nutritional strategy in piglets

This study evaluated the effect of dietary calcium (Ca) levels and deoxynivalenol (DON) contamination on Ca and phosphorus (P) utilization and bone mineralization in piglets. During an initial 13-d depletion phase, 64 piglets (15.7 ± 0.7 kg) received a control (DON-) or DON-contaminated treatment (DON+, 2.7 mg DON/kg) with either a low Ca (Ca-, 0.39%) or normal Ca level (Ca+, 0.65%) with a constant digestible P level (0.40%). A second group of 16 piglets received DON- or DON+ treatments for 9 d for gene expression analysis. During the subsequent 14-d repletion phase, all piglets were fed a Ca+ DON- diet containing 0.65% Ca and 0.35% digestible P without DON. After 5 d of the depletion phase, the absorption of P (DON × Ca; P < 0.05) and Ca was increased by the Ca- (P < 0.01) and DON+ (P < 0.01) diet. After 13 d, feed conversion ratio (P < 0.01) and average daily feed intake (P = 0.06) tended to decrease with the Ca- diet. The bone mineral content (BMC) gain was decreased by Ca, especially with Ca- DON + (DON × Ca, P < 0.05). The P absorption was increased by Ca- DON + (DON × Ca, P < 0.01), although the P retention efficiency was only increased by Ca+ DON + (DON × Ca, P < 0.001). The absorption of Ca was increased by DON+ (P < 0.001), and the Ca efficiency was increased by Ca- DON- (DON × Ca, P < 0.01). After 9 d, the gene expression of intestinal claudin 12 (P < 0.01) and CYP24A1 (P < 0.05), femur cortical RANKL (P < 0.05) and OPG (P = 0.06), and renal calbindin D9K (P < 0.05) and Klotho (P = 0.07) were decreased by DON+. The Ca (P = 0.06) and magnesium (P < 0.01) concentrations were decreased by DON+, and the Ca (P = 0.06) and P digestibility (P < 0.01) were increased. After the repletion phase, Ca- piglets recovered their BMC deficit, but not those receiving DON+ (DON × Ca; P = 0.06). The Ca (P < 0.05) and P (P = 0.06) retention efficiency tended to increase with Ca-. The absorption of Ca and P was increased by Ca- and DON+ (DON × Ca, P < 0.05). The results show that piglets increased their Ca and P utilization efficiency, allowing them to recover the BMC deficit caused by Ca-, but not when the piglets were exposed to DON. Pigs previously receiving Ca-deficient diet with DON still have lower body Ca and P, leading to elevated calcitriol concentrations and enhanced Ca and P intestinal absorption. The fact that DON decreased the expression of genes implicated in Ca intestinal and renal transport and P excretion after 9 d can potentially explain the reduced plasma Ca concentration.

Effects of sources and routes of administration of vitamins A, D and copper on postnatal status of these micronutrients in piglets

Twenty-six nulliparous sows were fed conventional gestation and lactation diets supplemented (N = 13) or not (N = 13) with extra daily supplements of 25-hydroxy-cholecalciferol (25-OH-D3; 4 ĸIU), β-carotene (24 ĸIU), and copper (Cu)-proteinate (45 mg) from day 90 of gestation to 21 d of lactation (L21). In each litter, 10 piglets were divided into 5 pairs received, at 2 (L2) and 8 d (L8) of age, one of the five combinations of micronutrient sources and routes of administration (N = 260 piglets total). These neonatal treatments (N = 26 pairs or 52 piglets each) consisted of oral vitamin D3, retinol acetate and CuSO4 (T1); oral 25-OH-D3, β-carotene, and Cu proteinate (T2); exposure to ultraviolet light (UVB), oral retinol palmitate and Cu gluconate (T3); intramuscular vitamin D3 and retinyl propionate and oral Cu acetate (T4); oral saline (CTRL). Oral or intramuscular provisions corresponded to 12 mg of Cu and 70 and 12 ĸIU of vitamins A and D, respectively. Blood samples were collected from all piglets at L2, L8, and L21 for determination of serum Cu, retinol, and 25-OH-D3. Body weight was measured at birth, L2, L8, and L21. Piglets were weaned at L21, and liver and blood samples were collected 2 d later to evaluate oxidative enzymes in blood and liver and hepatic ATP concentrations and expression of genes associated with antioxidant status. Sow treatments had marginal or no impacts on Cu, retinol, 25-OH-D3, or antioxidant status in piglet blood serum and liver. However, when supplements were given to piglets, hepatic Cu was 38% greater in for all treated piglets compared to CTRL (P < 0.01), hepatic retinol was 3 times higher in T1 than in CTRL (P < 0.01) and intermediate for other treatments whereas serum 25-OH-D3 was markedly increased with T2 and T3 at L8 and L21, respectively, compared to CTRL (Piglet treatment × Age interaction, P < 0.01). Concerning antioxidant activities, glutathione peroxidase, and superoxide dismutase were increased (P < 0.03) in plasma of T2 piglets whereas the highest values (P < 0.03) for indicators of oxidative damage to proteins were observed in T4 piglets. The study revealed that oral Cu proteinate from T2, oral retinol acetate from T1, oral 25-hydroxy-cholecalciferol from T2, and UVB light exposure from T3 were the most efficient ways of increasing the postnatal status of these micronutrients in suckling piglets and this may have some impacts on their peri-weaning antioxidant status.

Undergraduate students' motivational profiles before and during the COVID-19 pandemic: The role of educational climate and trait self-control

BACKGROUND

Universities faced important and sudden changes following the lockdown measures imposed during the COVID-19 pandemic. Traditional educational practices were disrupted as campuses were closed while distance learning was hastily adopted.

AIMS

This study documents the evolution of university students' autonomous and controlled motivation for their studies following campus closures by relying on a person-centred perspective. More specifically, it examines motivation profiles and their temporal stability across two time points taken before and during the pandemic, while also considering the role of educational climate, trait self-control and control variables (sex and age) as predictors of profile membership.

SAMPLE

A total of 1940 university students participated in this study by responding to online questionnaires at two time points, before (Time 1) and after (Time 2) the pandemic.

METHODS

We relied on latent profile and latent transition analyses to estimate motivation profiles, their temporal stability and their predictors.

RESULTS

A four-profile solution (Self-Determined, Moderately Motivated, Extrinsically Motivated, Amotivated) was selected and replicated at both time points. We observed a low degree of variability in profile membership over time, especially for the Amotivated profile. A need-supportive educational climate and trait self-control consistently predicted a greater likelihood of membership into more adaptative profiles (Self-Determined, Moderately Motivated).

CONCLUSIONS

The COVID-19 pandemic did not drastically change the motivational profiles of university students. Nevertheless, educational climate and self-control appeared to 'protect' students against the endorsement of more problematic motivation profiles both before and during the pandemic, making them important targets for intervention.

Vitamin D Supplementation Impacts Calcium and Phosphorus Metabolism in Piglets Fed a Diet Contaminated with Deoxynivalenol and Challenged with Lipopolysaccharides

Using alternative feed ingredients in pig diets can lead to deoxynivalenol (DON) contamination. DON has been shown to induce anorexia, inflammation, and-more recently-alterations in the vitamin D, calcium, and phosphorus metabolisms. Adding vitamin D supplementation in the form of vitamin D₃ and 25-OH-D₃ to the feed could modify the effects of DON in piglets. In this study, vitamin D₃ or 25-OH-D₃ supplementation was used in a control or DON-contaminated treatment. A repetitive exposure over 21 days to DON in the piglets led to disruptions in the vitamin D, calcium, and phosphorus metabolisms, resulting in a decreased growth performance, increased bone mineralization, and the downregulation of genes related to calcium and to phosphorus intestinal and renal absorption. The DON challenge also decreased blood concentrations of 25-OH-D₃, 1,25-(OH)₂-D₃, and phosphate. The DON contamination likely decreased the piglets' vitamin D status indirectly by modifying the calcium metabolism response. Vitamin D supplementations did not restore vitamin D status or bone mineralization. After a lipopolysaccharide-induced inflammatory stimulation, feeding a 25-OH-D₃ supplementation increased 25-OH-D₃ concentration and 1,25-(OH)₂-D₃ regulations during the DON challenge. DON contamination likely induced a Ca afflux by altering the intestinal barrier, which resulted in hypercalcemia and hypovitaminosis D. The vitamin D supplementation could increase the calcitriol production to face the combined LPS and DON challenge.

Weaning diet supplemented with health-promoting feed additives influences microbiota and immune response in piglets challenged with Salmonella

The aim of this study was to evaluate the potential of micronutrients and feed additives to modulate intestinal microbiota and systemic and mucosal immune responses in weaned pigs infected with Salmonella. At weaning, 32 litters of 12 piglets each were allocated to four dietary treatments: 1) control diet (CTRL), 2) CTRL supplemented with chlortetracycline (ATB), 3) CTRL supplemented with a cocktail of feed additives (CKTL); and 4) CKTL diet containing bovine colostrum in replacement of spray-dry animal plasma (CKTL+COL). The CKTL supplement included cranberry extract, encapsulated carvacrol and yeast-derived products and an enriched selenium and vitamin premix. Three weeks after weaning, four pigs per litter were orally inoculated with Salmonella Typhimurium DT104. Half of them were euthanized 3 days post-infection (dpi) and the other half, 7 dpi. The expression of IL6, TNF, IL8, monocyte chemoattractant protein 1 (MCP1), IFNG, cyclooxygenase 2 (COX2), glutathione peroxidase 2 (GPX2) and β-defensin 2 (DEFB2) showed a peaked response at 3 dpi (P < 0.05). Results also revealed that DEFB2 expression was higher at 3 dpi in CTRL and CKTL groups than in ATB (P = 0.01 and 0.06, respectively) while GPX2 gene was markedly increased at 3 and 7 dpi in pigs fed CKTL or CKTL+COL diet compared to CTRL pigs (P < 0.05). In piglets fed CKTL or CKTL+COL diet, intestinal changes in microbial communities were less pronounced after exposure to Salmonella compared to CTRL and progressed faster toward the status before Salmonella challenge (AMOVA P < 0.01). Furthermore, the relative abundance of several families was either up- or down-regulated in pigs fed CKTL or CKTL+COL diet after Salmonella challenge. In conclusion, weaning diet enriched with bovine colostrum, vitamins and mixture of feed additives mitigated the influence of Salmonella infection on intestinal microbial populations and modulate systemic and intestinal immune defences.

Examining the contribution of motivation in the job search of youth with developmental language disorder

BACKGROUND & AIMS

Youth with developmental language disorder (DLD) are at risk of experiencing challenges during their job search. It is thus crucial to promote efficient job search behaviors in terms of effort, intensity, and self-regulation. Based on self-determination theory (SDT), we verified the role of autonomous and controlled motivations in enhancing these behaviors.

METHODS

Study 1 included 37 young adults with DLD who have finished school, and Study 2 included 52 youth with DLD transitioning from school to work. They completed a questionnaire examining their job search behaviors and their motivation toward their job search.

RESULTS

Autonomous motivation positively predicted job search effort, intensity, and self-regulation. Small to moderate relations were observed in Study 1, and moderate to strong ones in Study 2. Controlled motivation was unrelated to the three behaviors.

CONCLUSIONS

In line with SDT, autonomous motivation is an important foundation for positive job search behaviors among youth with DLD.

IMPLICATIONS

Supporting the development of autonomous motivation is thus encouraged in transition services for this population.

Extracurricular activities and adjustment among students at disadvantaged high schools: The mediating role of peer relatedness and school belonging

INTRODUCTION

Participation in extracurricular activities (ECAs) during high school is likely to be associated with higher intrinsic motivation, as well as lower externalizing problems and depressive symptoms, particularly for students in schools located in socioeconomically disadvantaged neighborhoods. However, few studies have explored the processes underlying these positive associations. In this study, we examined whether peer relatedness and school belonging mediated the links between participation in these activities and adolescent academic and psychosocial adjustment and whether another indicator of poverty, namely material deprivation, moderated these links.

METHODS

Canadian students (n = 638; 59% girls) at disadvantaged high schools were surveyed at two-time points.

RESULTS AND CONCLUSIONS

Results show that peer relatedness can explain the associations between extracurricular activity participation and (a) school intrinsic motivation and (b) depressive symptoms. Results also revealed that the indirect effect involving the number of activities, peer relatedness, and depressive symptoms was only significant among students living in highly deprived areas. These results highlight the contribution of peer relatedness as a potential mediator of the positive association connecting extracurricular activity participation to adjustment among disadvantaged students.

Exogenous enzymes, meal size, and meal frequency: effect on ileal and total tract digestibility of carbohydrates, and energy and fiber degradation in growing pigs fed a wheat-barley grain-based high-fiber diet

When conducting a digestibility trial, pigs are usually fed only twice a day with a restricted feed intake which is not representative of the feeding conditions in a commercial farm. This study aimed to determine the effects of meal size and frequency, and exogenous enzymes (xylanase and phytase) on the digestibility of a high-fiber diet using porcine in vivo and in vitro approaches. Pigs (n = 6) were fitted with a T cannula, and each received all treatments using a 6 × 6 Latin square experimental design. The diets were supplemented (Enz) or not with a combination of xylanase and phytase and distributed into three feeding programs: one received two meals per day that met three times the maintenance energy requirement (2M), one received the same quantity of feed in eight meals (8M), and another received an amount that met five times the maintenance energy requirements in eight meals (8M+). For in vitro experiment, the degradability of fiber with or without xylanase supplementation only was determined. Enzyme supplementation increased apparent ileal digestibility (AID) of dry matter, starch, and degradation of insoluble non-starch polysaccharides (I-NSP) in all in vivo treatments (P < 0.05). The 2M compared with 8M increased the AID of starch and total tract digestibility of organic matter and I-NSP (P < 0.05). Enzyme supplementation decreased the content of insoluble arabinoxylan (P < 0.05) and increased arabinoxylan oligosaccharides (P < 0.05) in the in vivo ileal digesta and in vitro incubation. The results of this study confirm degradation by xylanase of the fiber fraction at the ileal level, which resulted in less fermentation of fiber in the large intestine. However, number and size of meals had little influence on feed digestibility. The consequences of shifting fiber fermentation more towards the upper part of the gastrointestinal tract need further investigation. The in vitro model provided a confirmation of the action of xylanase on the degradation of non-starch polysaccharides.

Educational contexts that nurture students' psychological needs predict low distress and healthy lifestyle through facilitated self-control

Psychological distress and unhealthy lifestyle behaviors are highly prevalent among undergraduate students. Importantly, numerous longitudinal studies show that these phenomena rise significantly during the first months of college and remain high thereafter. However, research identifying theory-driven mechanisms to explain these phenomena is lacking. Using two complementary statistical approaches (person- and variable-centered), this study assesses basic psychological needs (BPNs) and self-control as possible explanatory factors underlying the association between student's educational experience and multiple health-related outcomes. A total of 2450 Canadian undergraduates participated in this study study involving two time points (12 months apart; NTime1 = 1783; NTime2 = 1053), of which 386 participated at both measurement occasions. First, results from person-centered analyses (i.e., latent profile and transition analyses) revealed three profiles of need-satisfaction and frustration in students that were replicated at both time points. Need-supportive conditions within college generally predicted membership in the most adaptive profile. In turn, more adaptive profiles predicted higher self-control, lower levels of psychological distress (anxiety, depression), and healthier lifestyle behaviors (physical activity, fruit and vegetable consumption). Second, results from variable-centered analyses (i.e., structural equation modeling) showed that the association between students' BPNs and health-related outcomes was mediated by self-control. In other words, high need satisfaction and low need frustration were associated with higher self-regulatory performance at Time 1, which in turn predicted a more adaptive functioning at Time 2. Overall, these findings help clarify the mechanisms underlying the association between college educational climate and students' health-related functioning.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-022-04019-5.

Maternal depressive symptoms and children's academic performance: sex differences in the mediating role of school experiences

BACKGROUND

Maternal depressive symptoms (MDSs) are negatively associated with children's academic performance, with stronger effects sometimes reported in boys. However, few studies have tested the mechanisms of this association. We examined the mediating role of school engagement and peer victimization in this association and tested for sex differences.

METHODS

Participants were 1173 families from a population-based longitudinal Canadian study. MDSs were self-reported annually using the Centre for Epidemiologic Studies Depression Scale (child's age: 5 months to 5 years). Data on mediators (peer victimization, cognitive, behavioral, and emotional school engagement) were reported annually from ages 6-10 by multiple informants including children, parents, and teachers using items from validated scales. Mathematics, reading, and writing exam scores at age 12 were obtained from standardized exams administered by Québec's Ministry of Education and Teaching. Structural equation modeling was used to test mediation by school experiences in boys and girls.

RESULTS

Exposure to MDSs was negatively associated with mathematics, reading, and writing scores in girls and with mathematics only in boys. Cognitive and behavioral engagement significantly mediated the association between MDSs and mathematics, reading, and writing scores in girls. There were no significant mediators for boys.

CONCLUSIONS

Prevention and intervention strategies aiming to improve school engagement might be beneficial for daughters of mothers experiencing depressive symptoms. Further research is needed to replicate these findings and to identify the mechanisms explaining this association in boys.

69 Impact of DON in a Protocol of Calcium Depletion and Repletion in Piglets

This study aimed to evaluate factors that modulate phosphorus (P) use, such as calcium (Ca) intake that is well known and deoxynivalenol (DON) contamination which has been the subject of few studies until now. A total of 64 piglets (2 piglets per pen) received 1 of 4 treatments distributed into 8 blocks during an initial 13-d phase: control (DON-) or DON-contaminated treatment (DON+, 2.72 mg/kg) with either a low Ca (Ca-, 0.39%) or normal Ca (Ca+, 0.65%) level with a constant digestible P level (0.40%). During a second 14-d phase, piglets that received Ca+ and Ca- were fed a similar diet containing 0.65% Ca and 0.35% P without DON contamination. Growth performance and apparent total tract digestibility (ATTD) of Ca and P for piglets and bone mineral content (BMC) of 1 pig per pen were evaluated. After phase 1, ATTD P was higher for Ca-DON+ (DON x Ca interaction, P &lt; 0.01). The ATTD Ca was higher for DON+ (( P &lt; 0.001). The DON+ increased BMC in Ca+ but opposite effect was observed in Ca- (DON x Ca interaction, P &lt; 0.001). The plasma P concentration was greater for Ca- (P = 0.05). After phase 2, average daily gain (P = 0.08) and average daily feed intake (P = 0.09) tended to be less for Ca- than for Ca+. The Ca- piglets recovered their BMC deficit in DON-, but not those receiving DON+ (DON x Ca interaction, P = 0.06). ATTP P in DON- was lower in Ca+ but increased in DON+ regardless of Ca level (DON x Ca interaction, P = 0.04). Plasma P and Mg were greater for Ca- (P = 0.05). The results show that piglets can regain the BMC caused by Ca depletion in DON non-contaminated feed. DON contamination increased Ca and P digestibility and modified BMC depending on Ca supply.

Effect of oregano oil and cranberry pulp supplementation in finishing pigs on the physicochemical quality of fresh loin during storage

Oregano oil and cranberry pulp supplements were added to the diets of finishing pigs to determine their effects on the meat quality of fresh loins during storage. Two and three levels of oregano oil (250 and 500 mg·kg−1) and cranberry pulp (5, 10, and 20 g·kg−1) were tested, according to a factorial experimental design. The loin meat was vacuum packed and analyzed at 0 (after the 24 h chilling period post slaughter), 23, 45, and 60 d of storage. Samples were repackaged under aerobic conditions after 0 or 23 d and analyzed after 4, 8, and 12 d. Oregano and cranberry supplements did not affect lipid oxidation (microgram of malondialdehyde equivalent per kilogram of meat) during anaerobic or aerobic storage. On day 0, the fatty acid profile of the loin samples demonstrated that the addition of cranberries at a dose of 10 g·kg−1 was associated with a lower percentage of saturated fatty acids (P = 0.04; 42.97% vs. 40.99%) and a trend for a higher percentage of monounsaturated fatty acids (P = 0.06; 47.26% vs. 46.09%). Considering the result obtained, feeding pigs with oregano and cranberry supplements had a limited effect on meat quality parameters measured during storage.

Pathways to Student Motivation: A Meta-Analysis of Antecedents of Autonomous and Controlled Motivations

Students' self-determined motivation (acting out of interest, curiosity, and abiding values) is associated with higher academic well-being, persistence, and achievement. Self-determination theory posits that self-determined motivation is dependent on the satisfaction of three psychological needs (relatedness, competence, and autonomy), which are in turn facilitated through need-supportive behaviors from notable others. In this meta-analysis, conducted over 144 studies and more than 79,000 students, we sought to overview pathways to student motivation in order to verify (1) how do psychological needs rank in the strength of their prediction of self-determined motivation and (2) which autonomy-support providers (parents or teachers) are the most relevant for psychological need satisfaction in students and self-determined motivation. Results show that teacher autonomy support predicts students' need satisfaction and self-determined motivation more strongly than parental autonomy support. In addition, competence is the most positive predictor of self-determined motivation, followed by autonomy and then by relatedness.

Sociocultural Contexts and Relationships as the Cornerstones of Students' Motivation: Commentary on the Special Issue on the "Other Half of the Story"

This special issue on the development of academic motivation covers many issues that are groundbreaking in the field of motivation and interpersonal relationships. In this commentary, I discuss the following elements: (a) the challenges of integrating central motivational constructs; (b) interpersonal relationships as supports for motivation at school; (c) school or cultural contexts that sustain motivation; (d) new avenues for research. I hope that the articles in this special issue will stimulate new research that would have the potential to advance the field but that would also be useful to research professionals working day to day with children and adolescents.

The Relation Between Television Viewing Time and Reading Achievement in Elementary School Children: A Test of Substitution and Inhibition Hypotheses

Research has focused on the relations between television (TV) viewing time and children’s reading achievement. Two hypotheses have been proposed to explain this relation. The substitution hypothesis proposes that TV viewing distracts students from activities that are important for their learning. The inhibition hypothesis proposes that watching television inhibits important affective/cognitive skills. In this study, we test both hypotheses by estimating the relation between TV viewing time and reading achievement. We use the frequency of students’ leisure reading and the frequency of interactions between students and their parents as potential mediators to test the substitution hypothesis, whereas for the inhibition one, we use students’ intrinsic motivation to read and their level of inattention. Data come from the Québec Longitudinal Study of Child Development (QLSCD). Designed by the Institut de la statistique du Québec, QLSCD covers a wide range of themes. The QLSCD is representative of children in Québec and contains 2223 participants who were followed from 0 to 21 years old. The four structural models tested are built as follows: the TV viewing time at 6 years old predicts the four mediating variables at 8 years old, which in turn predicts reading achievement at 10 years old. In addition, we have tested models’ gender invariance. Results indicate that TV viewing time is not directly or indirectly associated with reading achievement. Specifically, it is not associated with the mediating variables of child-parent interactions, intrinsic motivation, and inattention. However, the frequency of leisure reading is negatively associated with the time spent watching TV. This association is very small (−0.07) and has no indirect effect on reading achievement. Finally, results do not vary according to the gender of the participants. Our results are in line with those of previous studies in the field and cast some doubts on the potential negative effects of TV viewing time on reading achievement.

Applying Self-Determination Theory to Education: Regulations Types, Psychological Needs, and Autonomy Supporting Behaviors

The self-determination theory (SDT) has been used to understand students’ motivation at school in general as well as in various school subjects. This literature review conducted on a number of SDT studies showed that (1) autonomous types of extrinsic motivation as well as intrinsic motivation leads to positive consequences for students; (2) the types of goals and the regulation behind them are also important to predict school outcomes; (3) when the psychological needs for competence, autonomy and relatedness are satisfied this leads to autonomous motivation or autonomous goals endorsement; (4) autonomy supportive practices by parents and teachers are important catalyzers of needs’ fulfillment; (5) intervention programs designed for teachers or parents focusing on these psychological needs usually lead to greater autonomous extrinsic motivation and intrinsic motivation and better adjustment outcomes. The implication of this theory for school psychologists is underscored as well as its implications for the practice of teaching.

Feed restriction and type of forage influence performance and behaviour of outdoor gestating sows

Forages can contribute to the nutrient supply for sows but the extent to which they can replace concentrate feeding is not well known. The objective of this study was to assess the effect of level of feed restriction and type of forage on the performance and activity of gestating sows under outdoor conditions. A total of 45 sows were distributed among three treatments, with five replicates of three sows/treatment, from week 5 of gestation until farrowing. Treatments differed in the daily level of concentrate feed provided and the type of forage offered during gestation: 90% of metabolisable energy (ME) requirements provided by concentrates and free access to a pasture (P90); 40% of ME requirements provided by concentrates and free access to a pasture (P40); and 40% of ME requirements provided by concentrates and free access to a bare paddock with hay ad libitum (H40). From farrowing to weaning (5 weeks), concentrate feed was offered to all sows ad libitum. Body weight and backfat thickness (BF) were measured seven times during gestation and lactation. Postures of sows and time spent in the pasture were assessed at the beginning, middle and end of gestation. Forage intake was estimated with a method based on sow performance using the InraPorc® model. At farrowing, P90 sows were heavier and had greater BF than P40 and H40 sows. At weaning, P90 sows maintained a higher BW and tended to have greater BF than H40 sows, but no longer differed from P40 sows. Treatments did not influence litter size, but piglets from P40 sows were lighter at birth than those from P90 sows (1.44 vs. 1.69 kg, P = 0.004). In late gestation, P90 sows spent less time standing over 24 h and less time in the pasture during daytime than P40 sows, suggesting less foraging behaviour. Sows fed concentrates to meet 40% of ME requirements during gestation did not consume enough forage to maintain the same body condition as sows fed at 90% of ME requirements. Despite their inability to fully compensate for concentrate restriction during gestation by consuming more forage, P40 sows reached a similar body condition to P90 sows at weaning. In conclusion, forage intake for outdoor gestating sows can compensate a concentrate feed reduction of 10% and possibly more, but not as much as 60%.

Effect of pelleting on nutrients and energy digestibility in growing pigs fed corn-soybean meal-based diet or diet containing corn distillers dried grains with solubles (cDDGS), wheat middlings, and bakery meal

This study was conducted to determine the effect of pelleting and diet type on the apparent ileal (AID) and total tract digestibility (ATTD) of nutrients and energy in growing pigs. Six pigs were cannulated at the ileum and were assigned to treatments following a crossover design. One diet was a control diet based on corn and soybean meal (CT). Part of it was replaced by corn distillers dried grains with solubles (cDDGS), wheat middlings, and bakery meal in the second diet (ByP). Diets were in mash (CT-MH and ByP-MH) or pelleted (CT-PT and ByP-PT) form. Results showed that pelleting increased digestibility in all diets with a distinct effect on the CT diet (interaction diet × pelleting, P < 0.05). Pelleting improved the AID of dry matter, crude protein, and energy by 17%, 27%, and 17% in the CT diet and by 10%, 9%, and 17% in the ByP diet (P < 0.01). The AID of amino acids followed the effect observed on crude protein (P < 0.01). Pelleting increased AID of total non-starch polysaccharides for the CT diet by 63% and 42% for the ByP diet (P < 0.01). The pelleting conditions improved the degradability of the compounds in the diets during digestion in pigs.

Impact of diet type and xylanase supplementation on the ileal digestibility of nutrients, and growth performance in growing-finishing pigs

In the experiment, six pigs fitted with a T-cannula at the distal ileum were fed six diets in a 6 × 6 Latin square design. Treatments were corn-soybean meal diet (CS), diet containing wheat by-products (WBP), and diet containing corn distillers dried grains with solubles and canola meal (DDCM) without or with xylanase (X) supplementation (CS-X, WBP-X, and DDCM-X). The WBP and DDCM diets had higher apparent ileal digestibility (AID) of lipids and acid detergent fiber (ADF) (P < 0.05) than CS diets. A xylanase × diet interaction was observed for the AID of neutral detergent fiber (NDF) (P < 0.05) showing larger impact of xylanase in WBP than in the other diets. Using similar dietary treatments except for CS-X, growth and body composition of the sixty males (83.0 kg) at the end of the 28-day growing phase showed that pig fed the CS diet had greater average daily feed intake (ADFI) (P = 0.004) and average daily gain (ADG) (P = 0.014) for period 0–14 d but not from 15–28 d. Overall performance (0–28 d) showed higher ADFI (9.5%; P = 0.015) in CS but no difference was observed for ADG and gain to feed ratio (G:F). These results showed that diets containing a high proportion of by-products can give equivalent performance to a CS diet and that adding xylanase for this short period had limited effects.

Toward Precise Nutrient Value of Feed in Growing Pigs: Effect of Meal Size, Frequency and Dietary Fibre on Nutrient Utilisation

Simple Summary

Feed costs are the most important in swine production. Precise determination of nutritional values of pig diets can help reducing feed costs by reducing security margins for nutrients and therefore provide a more sustainable swine production. In commercial farms, pigs have free access to feed and eat with no limitation according to their natural behaviour. In contrast, during digestibility trials, pigs are restricted in their daily intake of feed, which is distributed in a limited number of meals. The number of meals per day and the amount of feed consumed daily can affect the digestibility of the nutrients, the transit time and the metabolism. To reduce feed costs, by-products are frequently added to diets. Most by-products are rich in dietary fibre, which are known to have negative effects on digestibility. Enzymes can be supplemented in the diet to counteract the negative aspects of dietary fibre, but their efficiency can vary depending on the number of meals per day and the amount of feed consumed daily.

Abstract

Nutritional values of ingredients have been and still are the subject of many studies to reduce security margins of nutrients when formulating diets to reduce feed cost. In most studies, pigs are fed a limited amount of feed in a limited number of meals that do not represent how pigs are fed in commercial farm conditions. With free access to feed, pigs follow their intrinsic feeding behaviour. Feed intake is regulated by satiety and satiation signals. Reducing the feed intake level or feeding frequency can affect digestibility and transit time and induce metabolic changes. To reduce feed costs, alternative ingredients that are frequently rich in dietary fibre are added to diets. Fibre acts on the digestion process and transit time by decreasing energy density and causing viscosity. Various analyses of fibre can be realised, and the measured fibre fraction can vary. Exogenous enzymes can be added to counteract the effect of fibre, but digestive tract conditions, influenced by meal size and frequency, can affect the efficiency of supplemented enzymes. In conclusion, the frequency and size of the meals can affect the digestibility of nutrients by modulating gastrointestinal tract conditions (pH and transit time), metabolites (glucose and short-chain fatty acids) and hormones (glucagon-like peptide 1 and peptide tyrosine tyrosine).

The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth, antioxidant status, and vaccine response in weanling pigs

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS), and their combination on the growth, AOX status, and immune and vaccine responses against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg, and a grape seed extracts at 100 mg/kg feed (DON2.4 + AOX); DON2.4 diet + the mix of AOX and the modified HSCAS mentioned above (DON2.4 + AOX + HSCAS); DON2.4 + AOX + HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; on 0, 14, and 35 d, growth performance was recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response, and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared with the CTRL and DON1.2 groups (P ≤ 0.05). Compared with the DON2.4 diet, the AOX supplementation slightly reduced gain to feed ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association of AOX + HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared with the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 to 35 d and particularly in the DON2.4 + AOX pigs, whereas a different trend was evidenced in the DON2.4 + HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the AOX status and immune response of vaccinated weanling pigs.

Investigating how autonomy-supportive teaching moderates the relation between student honesty and premeditated cheating

BACKGROUND

Cheating at the post-secondary level is a skewed phenomenon. While personality and environmental factors are associated with cheating, few studies account for the zero inflation when predicting cheating behaviour.

AIM

In this study, we explore a person-situation interaction hypothesis where teacher autonomy support (AS) could modify the relation between students' honesty trait and premeditated cheating.

SAMPLE

Participants were 710 college students and 31 teachers.

METHODS

Teacher and student reports of teacher AS were collected and students also completed self-reports of honesty and premeditated cheating.

RESULTS

Given that cheating had a zero-inflated negative binomial distribution, we can investigate two separate outcomes: likelihood of cheating and magnitude of cheating. Predictably, student honesty trait predicted lower likelihood and magnitude of cheating. AS, whether student- or teacher-reported, moderated the relation between honesty and likelihood of cheating. In low perceived AS teaching environments, student honesty was associated with cheating likelihood. However, there was no such relation in high perceived AS teaching environments.

CONCLUSIONS

Students' honesty generally predicts lower cheating. However, the educational environment provided by the teacher influences the strength of this association. The less autonomy-supportive students perceive the educational environment, the more their personality is important in predicting the likelihood of cheating.

Social status and previous experience in the group as predictors of welfare of sows housed in large semi-static groups

Mixing gestating sows implies hierarchy formation and has detrimental consequences on welfare. The effects of social stress on the most vulnerable individuals may be underestimated and it is therefore important to evaluate welfare between individuals within groups. This study aimed at investigating the impact of social status and previous experience in the group on well-being of sows housed in large semi-static groups. We assessed aggression (d0 (mixing), d2, d27, d29), body lesions (d1, d26, d84) and feeding order on 20 groups of 46–91 animals. Social status was based on the proportion of fights won during a 6-hr observation period between d0 and d2. Dominants (29%) were those who won more fights than they lost, Subdominants (25%) won fewer fights than they lost, Losers (23%) never won any fight in which they were involved while Avoiders (23%) were never involved in fights. Resident sows (70%) were already present in the group in the previous gestation while New sows (30%) were newly introduced at mixing. Subdominants and Dominants were highly involved in fights around mixing but this was more detrimental for Subdominants than Dominants, Losers and Avoiders since they had the highest body lesion scores at mixing. Avoiders received less non-reciprocal agonistic acts than Losers on d2 (P = 0.0001) and had the lowest body lesion scores after mixing. However, Avoiders and Losers were more at risk in the long-term since they had the highest body lesions scores at d26 and d84. They were followed by Subdominants and then Dominants. New sows fought more (P<0.0001), tended to be involved in longer fights (P = 0.075) around mixing and had more body lesions throughout gestation than Resident sows. Feeding order from one-month post-mixing was influenced both by the previous experience in the group and social status (P<0.0001). New sows, especially with a low social status, are more vulnerable throughout gestation and could serve as indicators of non-optimal conditions.

34 Effect of Feeding Vitamin D Supplementation on Calcium and Phosphorus Metabolism When Piglets Are Fed a DON Contaminated Diet

DON has been shown to induce anorexia, oxidative stress, and more recently, alterations in calcium (Ca) and phosphorus (P) metabolism. It was thus hypothesized that vitamin D3 or 25-OH-D3 can counteract the effects of DON in piglets. The objectives were to confirm the DON effect and to evaluate the impact of a vitamin D supplementation on growth performance and Ca and P metabolism on piglets receiving a DON contaminated feed. A total of 66 piglets received one of the 6 treatments in 2 x 3 factorial design: control treatments (CON) or DON unsupplemented or supplemented with VitD3 or 25-OH-D3. After 21 days, piglets were weighted and feed intake was measured. Bone mineral content of each piglet was measured with dual-intensity X-ray absorptiometry at 21 days. Blood samples were taken to assess concentrations for VitD, P and Ca. Results showed that, DON reduced average daily feed intake and average daily gain (P &lt; 0.001). DON increased BMC per kg live body weight (P &lt; 0.001). Piglets fed DON diet had lower plasma concentrations of 25-OH-D3, 1,25-(OH)2-D3 and phosphate (P &lt; 0.001). The sodium-dependent phosphate transporter 1 (SLC20A2; P &lt; 0.050), sodium/calcium exchanger 1 (SLC8A1; P &lt; 0.032) and Klotho (P &lt; 0.014) gene expression was downregulated by DON contamination in intestinal mucosae. The calbindin d28K (CALB-1) (P &lt; 0.042), SLC8A1 (P &lt; 0.026), TRPV5 (P &lt; 0.041), calbindin d9K (S100G) (P &lt; 0.029) and Klotho (P &lt; 0.013) gene expression was downregulated by DON contamination in the kidney. The 1α-hydroxylase gene expression tended to be downregulated by DON contamination in the kidney as well. The VitD3 and 25-OH-D3 supplementation upregulated vitamin D receptor (VDR, DON x VitD, P &lt; 0.014), SLC8A1 (DON x VitD, P &lt; 0.036) and Klotho (DON x VitD, P &lt; 0.025) in intestinal mucosae, although those gene expressions were downregulated by DON contamination. Thus, DON induced an alteration of vitamin D-calcium-phosphorus metabolism by modifying Ca utilization from mechanisms still under investigation.

Student Motivation and Associated Outcomes: A Meta-Analysis From Self-Determination Theory

Student outcomes are influenced by different types of motivation that stem from external incentives, ego involvement, personal value, and intrinsic interest. The types of motivation described in self-determination theory each co-occur to different degrees and should lead to different consequences. The associations with outcomes are due in part to unique characteristics and in part to the degree of autonomy each entails. In the current meta-analysis, we examine these different types of motivation in 344 samples (223,209 participants) as they relate to 26 performance, well-being, goal orientation, and persistence-related student outcomes. Findings highlight that intrinsic motivation is related to student success and well-being, whereas personal value (identified regulation) is particularly highly related to persistence. Ego-involved motives (introjected regulation) were positively related to persistence and performance goals but also positively related with indicators of ill-being. Motivation driven by a desire to obtain rewards or avoid punishment (external regulation) was not associated with performance or persistence but was associated with decreased well-being. Finally, amotivation was related to poor outcomes. Relative weights analysis further estimates the degree to which motivation types uniquely predict outcomes, highlighting that identified regulation and intrinsic motivation are likely key factors for school adjustment.

The combination of nutraceuticals and functional feeds as additives modulates gut microbiota and blood markers associated with immune response and health in weanling piglets

This study aimed to evaluate the effects of a combination of feed additives with complementary functional properties on the intestinal microbiota, homocysteine, and vitamins E and B status as well as systemic immune response of weanling piglets. At weaning, 32 litters were assigned to one of the following dietary treatments (DT): 1) conventional diet (CTRL); 2) CTRL diet supplemented with antibiotics (ATB); 3) a cocktail of feed additives containing cranberry extract, encapsulated carvacrol, yeast-derived products, and extra vitamins A, D, E, and B complex (CKTL); or 4) CKTL diet with bovine colostrum in replacement of plasma proteins (CKTL + COL). Within each litter, the piglets with lowest and highest birth weights (LBW and HBW, respectively) and two piglets of medium birth weight (MBW) were identified. The MBW piglets were euthanized at 42 d of age in order to characterize the ileal and colonic microbiota. Blood samples were also collected at weaning and at 42 d of age from LBW and HBW piglets to measure insulin-like growth factor-1 (IGF-1), cysteine, homocysteine, and vitamins E, B₆, and B₁₂, and to characterize the leukocyte populations. At 42 d of age, cytokine production by stimulated peripheral blood mononuclear cells was also measured. In a second experiment, piglets were reared under commercial conditions to evaluate the effects of the DT on the growth performance. At the indicator species analysis, the highest indicator value (IV) for Succinivibrio dextrinosolvens was found in the CKTL group, whereas the highest IV for Lactobacillus reuteri and Faecalibacterium prausnitzii was evidenced in the CKTL + COL group (P < 0.05). Compared with the other DT, CTRL piglets had higher concentrations of homocysteine, whereas the CKTL and CKTL + COL supplementations increased the concentrations of vitamins E and B₁₂ (P < 0.05). DT had no effect on IGF-1 concentration and on blood leukocytes populations; however, compared with HBW piglets, LBW animals had lower values of IGF-1, whereas the percentages of γδ T lymphocytes and T helper were decreased and increased, respectively (P < 0.05). CKTL + COL also improved the growth performance of piglets reared under commercial conditions (P < 0.05). This study highlights the impact of birth weight on piglet systemic immune defenses and the potential of weaning diet supplemented with feed additives and bovine colostrum to modulate the homocysteine metabolism and the intestinal microbiota.

398 Towards new feeding approaches for optimizing nutritional status, immunity and host-microbiota interactions in neonatal and weaned piglets

Lactation, feeding conditions, microbial interventions and piglet growth in the first few weeks of life have important impact on the intestinal microbiota establishment and immune system development of piglets. Indeed, colostrum and milk contain various bioactive components such as immune factors, antimicrobial peptides and oligosaccharides that contribute to maintain intestinal homeostasis and regulate interactions between microbiota and host immune system. Recent results revealed that low birth weight piglet (LBWP) with poor weight gain during the first two weeks of life develop different intestinal microbiota and immune response profiles compared to high BWP (HBWP) littermates. Consequently, piglets within litters may have different resilience to infections after weaning and benefit from feed additives in a specific manner. A study has been performed to evaluate the potential of bovine colostrum extract (BC) as replacement to plasma proteins for improving gut health and resilience to Salmonella infection in piglets. Results revealed that in weaned piglets fed BC, intestinal microbiota was differently modulated and bacterial dysbiosis induced by Salmonella was restored faster. Moreover, expression of genes involved in innate immunity such as β-defensin-2 and glutathione peroxidase-2 was respectively down- and up-regulated in BC fed piglets. A combination of dietary supplementation with BC, cupper and vitamins A and D has also been tested in LBWP and HBWP, and there is clear evidence that BC in combination with other feed additives promote growth and gut health in both LBWP and HBWP. The porcine intestinal epithelial cell line IPEC-J2 was used to better understand the functional properties of BC. Results indicated that BC improves wound healing, enhances barrier function and modulates the expression of several genes involved in innate immune response. Finally, as microbial intervention, the potential of fecal transplantation to modulate intestinal microbiota and immune system development of piglets is under investigation and will be discussed.

PSIV-21 Pellet processing reduces variability of corn soybean meal-based diet digestibility in growing pigs

This study was conducted to determine the effect of pelleting on the digestibility of corn-soybean meal-based diet in growing pigs. Two trials with 6 pigs cannulated at the distal ileum were conducted. In each trial, pigs were assigned to each treatment following a crossover design. In each experiment, the same diet, composed of corn and soybean meal with 10% wheat from two different feed mills, was served in pellet or mash form. Pelleting allowed an increase in digestibility in one of the trials. Apparent ileal digestibility (AID) of dry matter (DM), crude protein (CP) and digestible energy (DE) were improved with pelleting by 8, 12 and 9% (P&lt; 0.01). The AID of amino acids (AA) was also improved (P&lt; 0.05). Apparent total tract digestibility (ATTD) was increased by pelleting in DM, CP and DE by 5, 7 and 6% respectively (P&lt; 0.01). The digestibility of the mash diet in experiment 1 was lower than in the pelleted diet in the experiment 1 and both diets in experiment 2 as shown by the interaction Pelleting X Trial which was significant for the AID and ATTD of DM, CP and DE (P&lt; 0.01). Therefore, in experiment 1, pelleting allows to improve the digestibility of diet to the same level as in experiment 2. The AID of CP was higher by 37% in the mash diet from the second experiment compared to the one in the first experiment. Even though the same ingredients were chosen in the two experiments, this shows the variability in digestibility existing between different feed mills and ingredient sources. This difference was not observed in pelleted diets. The results obtained in these two trials show that pelleting can reduce the variability of digestibility and then give a good digestibility of diets even if the ingredients are of different quality or sources.

Young Adults With Developmental Language Disorder: A Systematic Review of Education, Employment, and Independent Living Outcomes

Purpose Research on developmental language disorder (DLD) in adulthood has increased rapidly in recent years. However, to date, there has been no systematic literature review on this topic, thereby limiting the possibility to have a comprehensive overview of publications in this field. Method Following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, we conducted a systematic literature review. A literature search was undertaken in four databases, from 2005 to 2018. We selected articles with original data related to life outcomes of young adults with and without DLD, all aged between 18 and 34 years, in three life areas: education, employment, and independent living. Methodological characteristics of the studies were analyzed. Results Fifteen articles were selected with longitudinal designs. In every life area, young adults with DLD were compared to their typically developing peers to identify their strengths and weaknesses. The predictive role of language abilities was also examined. Conclusions Outcomes within each life area are heterogeneous. Nevertheless, similarly to young children and adolescents, young adults with DLD face numerous challenges. Although language abilities partly predict some of these outcomes, much of the variance remains unaccounted for and some outcomes are unrelated to this predictor. This systematic literature review has implications for researchers and practitioners to identify promising avenues for research, interventions, and policy development. Supplemental Material https://doi.org/10.23641/asha.13022552.

Impact of birth weight and neonatal nutritional interventions with micronutrients and bovine colostrum on the development of piglet immune response during the peri-weaning period

Immune system development of piglets is influenced by birth weight and colostrum and milk intake. Moreover, the dam transfer to piglets of vitamins A and D and copper, which play important role in immunity, is limited during lactation. In this study, we evaluated the potential of maternal and neonatal supplementations with vitamins A and D and copper, with or without neonatal supplementation of bovine colostrum (BC), to modulate the immune system development of low birth weight (LBW) and high birth weight (HBW) piglets during the peri-weaning period. Litters from 23 control sows (CONT) were assigned to one of the following treatments: 1) control (C); 2) oral administration at 2 and 8 days (d) of age of retinol-acetate, 25-hydroxyvitamin D and CuSO₄ and exposure to UVB light for 15 min every second day from d 5 to d 21 (ADCu); 3) oral administration of dehydrated BC (4 g/d) from d 5 to d 10 (BC); 4) ADCu + BC. This experimental design was repeated with 24 sows fed extra daily supplements of 25-hydroxyvitamin D (4,000 IU), β-carotene (30,000 IU) and Cu-yeast (equivalent 45 mg of Cu) from 90 d of gestation until weaning at d 21 (SUPPL). Within each litter, 2 LBW and 2 HBW piglets were euthanized at d 16 and d 23 in order to characterize leukocyte subsets in mesenteric lymph nodes (MLN) and blood by flow cytometry, and to measure gene expression in the MLN and jejunal mucosa by qPCR. At d 16, results revealed that the percentages of γδ and cytotoxic T lymphocytes were significantly reduced in LBW compared to HBW piglets. The jejunal expression of interleukin (IL) 22 was also up-regulated, along with MLN expression of C-C Motif Chemokine Ligand 23, bone morphogenetic protein 2 and secreted phosphoprotein 1 (SPP1), whereas jejunal expression of tumor necrosis factor α was decreased in LBW piglets. At d 23, LBW piglets showed lower amounts of γδ T lymphocytes, higher percentages of CD3^- and CD3^-CD8α⁺CD16⁺ leukocytes (which include Natural killer cells) and lower jejunal expression of IL18. Furthermore, supplementation with BC increased the blood percentage of CD3^-CD16⁺ leukocytes and reduced jejunal IL5 and MLN IL15 expression whereas supplementation with ADCu + BC increased jejunal TNF superfamily 13B and MLN SPP1 expression. Our results suggest that immune system development after birth differed between LBW and HBW piglets and that early dietary supplementation with BC and ADCu has the potential to modulate development of immune functions.

Dynamic modeling of nutrient use and individual requirements of lactating sows1

Nutrient requirements of sows during lactation are related mainly to their milk yield and feed intake, and vary greatly among individuals. In practice, nutrient requirements are generally determined at the population level based on average performance. The objective of the present modeling approach was to explore the variability in nutrient requirements among sows by combining current knowledge about nutrient use with on-farm data available on sows at farrowing [parity, BW, backfat thickness (BT)] and their individual performance (litter size, litter average daily gain, daily sow feed intake) to estimate nutrient requirements. The approach was tested on a database of 1,450 lactations from 2 farms. The effects of farm (A, B), week of lactation (W1: week 1, W2: week 2, W3+: week 3 and beyond), and parity (P1: 1, P2: 2, P3+: 3 and beyond) on sow performance and their nutrient requirements were evaluated. The mean daily ME requirement was strongly correlated with litter growth (R2 = 0.95; P < 0.001) and varied slightly according to sow BW, which influenced the maintenance cost. The mean daily standardized ileal digestible (SID) lysine requirement was influenced by farm, week of lactation, and parity. Variability in SID lysine requirement per kg feed was related mainly to feed intake (R2 = 0.51; P < 0.001) and, to a smaller extent, litter growth (R2 = 0.27; P < 0.001). It was lowest in W1 (7.0 g/kg), greatest in W2 (7.9 g/kg), and intermediate in W3+ (7.5 g/kg; P < 0.001) because milk production increased faster than feed intake capacity did. It was lower for P3+ (6.7 g/kg) and P2 sows (7.3 g/kg) than P1 sows (8.3 g/kg) due to the greater feed intake of multiparous sows. The SID lysine requirement per kg of feed was met for 80% of sows when supplies were 112 and 120% of the mean population requirement on farm A and B, respectively, indicating higher variability in requirements on farm B. Other amino acid and mineral requirements were influenced in the same way as SID lysine. The present modeling approach allows to capture individual variability in the performance of sows and litters according to farm, stage of lactation, and parity. It is an initial step in the development of new types of models able to process historical farm data (e.g., for ex post assessment of nutrient requirements) and real-time data (e.g., to control precision feeding).

Effects of deoxynivalenol and sodium meta-bisulphite on nutrient digestibility in growing pigs

Deoxynivalenol (DON), a mycotoxin synthesised by the Fusarium, is known to affect the growth of pigs. This effect can be attenuated with sodium meta-bisulphite (SBS). The aim of this study was to evaluate the effect of SBS with antioxidant blend on nutrient digestibility in pigs fed a diet contaminated naturally with DON. Six crossbred castrated pigs fitted surgically with single-T cannulas in the distal ileum received one of four barley-corn-soybean diets with or without SBS. After 8 d of feeding, faeces and ileal digesta were collected for 2 d. Apparent ileal digestibility (AID) of the dry matter (DM), energy, nutrients and DON, and apparent total tract digestibility (ATTD) of DM, acid detergent fibre (ADF), neutral detergent fibre (NDF), energy and DON were evaluated. The AID of phosphorus, calcium and some amino acids was increased (p < 0.05) in the DON diets whereas the ATTD of DM and energy tended to decrease (p = 0.064 and p = 0.071). SBS reduced the AID of DM, energy, ADF, ether extract, phosphorus and DON (p < 0.05) but had no effect on the ATTD of DM, energy, fibre or DON. These results show that DON improved the AID of some nutrients but tended to reduce the ATTD of energy, which could explain, although anorexia is the main effect of DON on live weight gain, the reported negative effect of DON on pig growth. Finally, SBS with antioxidant blend had reduced AID of some nutrients and intestinal absorption of DON.

Piglet weight gain during the first two weeks of lactation influences the immune system development

The aim of this study was to investigate the effect of the piglet growth during the first week of life on ileal expression of genes and on development of the immune system. Eight litters adjusted to 12 piglets were used. Within each litter, the piglet that showed the lowest weight gain (LWG; n = 8) and the one that showed the highest weight gain (HWG; n = 8) in their first week of life were enrolled. Peripheral blood mononuclear cells (PBMC) were isolated on days 8 and 16 to characterize cellular population profiles and to assess ex-vivo secretion of interleukin-10 (IL-10), IL-6 and tumor necrosis factor-α (TNF-α). On day 16, piglets were euthanized and ileum samples were collected to extract RNA for microarray analysis and gene expression by qPCR. As expected, growth performance of LWG piglet was impaired compared to HWG piglets (P < 0.05). From day 8 to 16, the percentage of CD21⁺ B cells significantly increased in blood of heavier HWG piglets while the percentage remained constant in smaller LWG piglets (P weight x day = 0.01). For the CD4⁺CD8α^- Th cells, a marked increase was observed in LWG piglets from 8 to 16 days of age (P =  0.002) whereas no significant change occurred in HWG piglets. Percentages of CD14⁺ monocytes and other MHC-II⁺ cells were respectively higher and lower on day 8 compared to day 16 for both groups of piglets (P <  0.01). On day 8, LPS-activated PBMC from LWG piglets produced less IL-6 compared to HWG piglets (P <  0.05). Microarray analysis of gene expression in piglets' ileum tissue indicated that several genes involed in defense response and response to oxidative stress were modulated differently in LWG compared to HWG. Gene analysis by Q-PCR confirmed microarray results and revealed that IL-10, SOD1, NOS2, NOD2, TLR4, TLR9, CD40 and CD74 expressions were significantly decreased (P < 0.05) in LWG in comparison to HWG piglets, while MYD88 and NFkBiA showed a tendency to decrease (0.05 ≤ P < 0.07). These results suggest that birth weight and milk intake affect the growth performances and the development of immunity by modulating the expression of genes associated with immunity and oxidative stress in piglets' intestinal tissue, and by affecting the leukocyte populations involved in innate and cell-mediated immunity in nursing piglets. Therefore, impaired development of immune system in LWG piglets might have an impact on their resistance to infections later in life.

Birth weight affects immune response of piglets during the peri-weaning period

Relationships between birth weight and a range of immune markers were studied in piglets during the peri-weaning period. A total of 47 sows and their respective litters adjusted to 12 piglets were used. Piglets were weighed after birth and within each litter 2 low weight (LW) and 2 high weight (HW) animals were identified: the average weight of the 2 groups was 1.12 and 1.81 ± 0.17 kg, respectively. Within litter, one couple of LW and HW piglets was sacrificed at 16 and 23 d of age, two days after weaning at day 21, to characterise different leukocyte subsets in mesenteric lymph nodes (MLN) and blood by flow cytometry. Jejunal mucosal and MLN samples were also collected to measure the expression of genes involved in immune response by qPCR. The percentage of blood γδT cells was higher in HW piglets before and after weaning (P=0.01 and P&lt;0.001, respectively). At 16 d, LW animals had higher amounts of CD4+CD8+ T cells and dendritic cells in the blood (P=0.01 and P=0.04, respectively) and in MLN (P=0.02 and P=0.009 respectively), and lower count of blood cytotoxic T cells (P=0.01) than HW. Moreover, jejunal expression of TNFα was reduced in LW piglets (P=0.02), while MLN expression of CCL23, BMP2 and SPP1 was increased (P=0.003, P=0.002 and P=0.02, respectively). Two days after weaning (d 23), HW piglets had higher percentages of T cells (P=0.001) and lower amount of non-T cells (P=0.03) and natural killer cells (P=0.04) in blood compared to LW animals. These data revealed that piglet birth weight affects the proportion of leukocyte subsets in different tissues and the expression of genes involved in the immunity. Globally, our results suggest that the development of the immune system after birth differed between LW and HW piglets.