Effects of the feeding challenge and age (median and IQR) on acute insulin response to glucose (AIRg), insulin sensitivity (IS), disposition index (DI) and glucose effectiveness (Sg), basal plasma glucose (GB) and basal plasma insulin (IB) in yearlings whose dams were fed with barley and forage (B, n = 10) or forage only (F, n = 10), at 19 and 24 months of age.

<p>Effects of the feeding challenge and age (median and IQR) on acute insulin response to glucose (AIRg), insulin sensitivity (IS), disposition index (DI) and glucose effectiveness (Sg), basal plasma glucose (GB) and basal plasma insulin (IB) in yearlings whose dams were fed with barley and forage (B, n = 10) or forage only (F, n = 10), at 19 and 24 months of age.</p

quality of feedstuff from INRA [29] given to yearlings during feeding challenge (19 to 24 months).

<p>quality of feedstuff from INRA [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0169295#pone.0169295.ref029" target="_blank">29</a>] given to yearlings during feeding challenge (19 to 24 months).</p

Summary of the number of foals included in each analysis.

<p>Summary of the number of foals included in each analysis.</p

Schematic representation of the Bergman’s minimal model (adapted from [34–36,38]).

<p>Glucose is produced and released by the liver in a basal state. After a meal, or a glucose intra-venous injection, the levels of plasma glucose increase. From the blood, the glucose will be disposed in the peripheral tissues by two ways: </p><p></p><p></p><p>By itself. The glucose efficiency (<b>Sg</b>) is the capacity of the glucose to mediate its own disposal.</p><p></p><p></p><p>Mediated by insulin. The elevated concentration of blood glucose induces the production of insulin by the pancreas. The acute insulin response (<b>AIRg</b>) represents the production of insulin by the pancreas during the first 10 minutes after glucose injection. Insulin is transferred into the interstitial space (<b>P3—insulin introduction rate</b>) from the bloodstream and reaches the peripheral tissues to mediate glucose disposal (<b>X -insulin action</b>). With time, insulin action declines at a rate calculated by the <b>P2</b> proxy. <b>Insulin sensitivity</b> (<b>IS</b>) is calculated as P2/P3.</p><p></p><p></p><p></p> <p>By itself. The glucose efficiency (<b>Sg</b>) is the capacity of the glucose to mediate its own disposal.</p> <p>Mediated by insulin. The elevated concentration of blood glucose induces the production of insulin by the pancreas. The acute insulin response (<b>AIRg</b>) represents the production of insulin by the pancreas during the first 10 minutes after glucose injection. Insulin is transferred into the interstitial space (<b>P3—insulin introduction rate</b>) from the bloodstream and reaches the peripheral tissues to mediate glucose disposal (<b>X -insulin action</b>). With time, insulin action declines at a rate calculated by the <b>P2</b> proxy. <b>Insulin sensitivity</b> (<b>IS</b>) is calculated as P2/P3.</p> <p>Finally, the disposition index (<b>DI</b>) (multiplication of IS and AIRg) is used to describe β-cells responsiveness.</p

Immunohistochemical detection of PCNA protein in equine prepubertal testes.

<p>Representative testicular sections for foals born to forage fed (A, n = 6), or barley and forage fed dams (B, n = 7), with respective negative controls (C and D). Lumen scores are represented within each tubule for F foals in testicular section (E) and B foals in testicular section (F). Arrow heads indicate Sertoli cells, white arrows, gonocytes and black arrows, peritubular cells. ST: seminiferous tubule, IT: interstitial tissue, V: vacuoles. All cellular types constituting the seminiferous epithelium, Sertoli cells and gonocytes are positive for PCNA staining. Scale bar = 0.05 mm.</p

Experimental design from insemination of the broodmares until foals’ 24 months of age.

<p>From insemination until 7 months of gestation, pregnant mares were managed as one same herd in the same pasture. From the 7^th month of gestation, they were housed in individual boxes and allocated to one of two groups: fed with forage only (F, n = 12) or with forage and flattened barley (B, n = 12) until foaling. From 3 days until 6 months of age, foals were in pasture with their dams [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0169295#pone.0169295.ref031" target="_blank">31</a>]. They were weaned at 6 months and housed in open barns and fed the same amount of feed, following the INRA recommendations for growing foals [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0169295#pone.0169295.ref029" target="_blank">29</a>]. Colts were castrated at 12 months as a routine procedure. From 12 to 19 months of age, all yearlings were managed in the same pasture. At 19 months of age, all yearlings were housed in open barns and between 20 and 24 months of age, they were over nourished using an automatic feeder (+140% of INRA energy requirements, +135% of NRC energy requirements hatched part).</p

Effects of the feeding challenge and age (median and IQR) on acute insulin response to glucose (AIRg), insulin sensitivity (IS), disposition index (DI) and glucose effectiveness (Sg), basal plasma glucose (GB) and basal plasma insulin (IB) in yearlings whose dams were fed with barley and forage (B, n = 10) or forage only (F, n = 10), at 19 and 24 months of age.

<p>Effects of the feeding challenge and age (median and IQR) on acute insulin response to glucose (AIRg), insulin sensitivity (IS), disposition index (DI) and glucose effectiveness (Sg), basal plasma glucose (GB) and basal plasma insulin (IB) in yearlings whose dams were fed with barley and forage (B, n = 10) or forage only (F, n = 10), at 19 and 24 months of age.</p

Primers sequences used for amplification of equine products in RT-qPCR assays in testicles of prepubertal colts.

<p>Primers sequences used for amplification of equine products in RT-qPCR assays in testicles of prepubertal colts.</p

Mares FSIGT

Data from the Frequently Sampled Intravenous Glucose Tolerance Test (FSIGT) performed in mares at 300 days of gestation. AIRg=Acute pancras response, DI=Disposition index, SI=Insulin sensitivity, Sg=Glucose effectivness, GB=Basal glucose, IB=Basal insulin

Foals FSIGT

Data from the Frequently Sampled Intravenous Glucose Tolerance Test (FSIGT) performed in growing foals at 180, 360 and 540 days of age. AIRg=Acute pancras response, DI=Disposition index, SI=Insulin sensitivity, Sg=Glucose effectivness, GB=Basal glucose, IB=Basal insulin