Parity affects mammary development in late-pregnant swine

The goal of this project was to determine whether various measures of mammary development differed between gilts and multiparous sows at the end of gestation. During gestation, Yorkshire × Landrace gilts (n = 19) and sows (second and third gestations, n = 17) were fed one daily meal of a conventional corn-based diet, where the amount fed was based on body weight (BW) and backfat thickness (BF) at mating. On day 110 ± 1 of gestation, a jugular blood sample was obtained from all gilts and sows to measure insulin-like growth factor-1 (IGF-1), glucose, free fatty acids, and urea. On that same day, BW and BF were measured and animals were euthanized. Mammary glands from one side of the udder were dissected for compositional analyses. The fifth gland of the contralateral row of mammary glands was sampled for histology and immunohistochemical localization of Ki67. There was less total parenchyma (1,437.4 vs. 2,004.7 ± 127.1 g; P < 0.001) and total extraparenchymal tissue (1,691.0 vs. 2,407.0 ± 125.3 g; P < 0.001) in mammary glands of gilts compared to those from sows. When these values were expressed per kg BW (226.0 and 284.0 ± 2.7 kg for gilts and sows, respectively), parenchymal mass did not differ (P > 0.10), while extraparenchymal tissue weight tended to be less in gilts than sows (P = 0.07). All components within the parenchyma differed by parity (P < 0.001). Specifically, parenchymal tissue from gilts contained a greater proportion of fat and dry matter (DM), a lower proportion of protein, and lower concentrations of DNA (6.59 vs. 9.35 ± 0.53 mg/g DM) and RNA (7.76 vs. 12.33 ± 0.70 mg/g DM) than that from sows. On the other hand, the circumference of alveolar lumens was greater in gilts than sows (P < 0.001), while the percentage of epithelial cells that were positive for Ki67, a marker of cell proliferation, was greater in sows than gilts (P < 0.05). Circulating concentrations of IGF-1 were greater in gilts than in multiparous sows (45.0 vs. 27.3 ± 2.8 ng/mL, P < 0.001). None of the other blood variables were changed by parity. Results show a marked effect of parity on mammary gland development in swine. At the end of gestation, the mammary glands of gilts had less parenchyma with lower epithelial proliferation than glands from multiparous sows. These differences could alter the response of mammary tissue to various nutritional or endocrine signals. This information is crucial for the development of management strategies designed to maximize sow milk yield.

Optimal protein concentration in diets for sows during the transition period

The aim of the present study was to determine the optimal concentration of dietary protein required in transition diets for multiparous sows that enhance the farrowing process, colostrum production, and subsequent lactation performance. Forty-eight multiparous sows were allotted to one of six dietary treatments according to body weight (290 ± 3 kg) and parity (3.8 ± 0.2) from day 108 of gestation until 24 h after the onset of farrowing. The diets were isoenergetic and contained increasing concentrations of dietary protein (expressed as standardized ileal digestible [SID] Lys) and were supplied at a daily feed supply of 3.8 kg. On day 108 of gestation and days 2, 7, 14, 21, and 28 of lactation, body weight, and back fat thickness were recorded, and blood was sampled on day 108 of gestation, at the onset of farrowing, and days 3, 10, 17, and 24 of lactation from the sows for analysis of plasma metabolites. On day 115 of gestation, urine, and feces were collected for nitrogen (N) balance. The number of liveborn and stillborn piglets and time of birth were recorded and blood from every fourth piglet was sampled at birth for blood gas analysis. Piglets were weighed individually from birth until weaning, to estimate the colostrum and milk yield of the sows. Colostrum and milk samples were collected, and their compositions were determined. On days 3 and 28 of lactation, sows were injected with deuterium oxide to estimate body composition. The N utilization was maximized when the concentration of SID Lys in the transition diet was 6.06 g/kg (P < 0.01). When urinary concentrations of urea were expressed relative to creatinine, the relative concentration of urea remained low until a dietary concentration of 6.08 g SID Lys/kg, above which the relative concentration of urea increased (P < 0.01). Stillbirth rate increased linearly with increasing SID Lys concentration in the transition diet (P < 0.001), thus the concentration of SID Lys should be kept as low as possible without impairing sow performance excessively. A carry-over effect on milk yield was observed, showing that a dietary SID Lys concentration of 5.79 g/kg during transition optimized milk production at an average yield of 13.5 kg/d (P = 0.04). Increasing loss of body fat in lactation was observed with increasing SID Lys concentration in the transition diet (P = 0.03). In conclusion, the transition diet of multiparous sows should contain 5.79 g SID Lys/kg when fed 3.8 kg/d (13.0 MJ ME/kg), for a total SID Lys intake of 22 g/d.

Oral administration of domperidone in the first or third week of lactation: effects on prolactin concentrations and mammary gene expression in sows and piglet growth

The scope of the present study is endocrine and metabolic control of sow lactation. This project aimed to determine the impact of increasing prolactin concentrations via oral administration of the dopamine receptor antagonist domperidone in the first or third week of lactation in sows. Effects on sow hormonal and metabolic status, lactational performance, and gene expression in mammary epithelial cells were determined. Primiparous sows were divided in 3 treatments: 1) 10 mL of vehicle (table syrup) per os twice daily during the first and third weeks of lactation (Control, CTL, n = 23), 2) 0.5 mg/kg of domperidone per os twice daily during the first week of lactation (LACT1, n = 23), or 3) 0.5 mg/kg of domperidone given per os twice daily during the third week of lactation (LACT3, n = 22). Treated sows also received 10 mL of the vehicle twice daily during the other treatment period. Litter size was standardized to 12 ± 1 and piglets were weighed at birth, 24 h, and on d 8, 15, 22 (weaning), 35, and 56. Sow feed intake was recorded daily. Representative milk samples were obtained on d 7 and 21 of lactation for compositional analyses, and milk fat globules were used to measure mRNA abundances of various genes. Jugular blood samples were obtained from sows on d 1, 7, 14, and 21 of lactation to measure concentrations of prolactin, IGF-1, insulin, urea, and FFA. Concentrations of prolactin were increased (P < 0.01) at the end of the 7-d treatment period with domperidone, whether imposed in the first (LACT1) or third (LACT 3) week of lactation. No other blood variables were affected by treatments and neither was milk composition (P > 0.10). Sow BW, backfat thickness, or feed intake were not altered by treatments (P > 0.10), but piglet BW tended to be greater in litters from LACT3 compared with CTL sows on d 22 and 35 (P ≤ 0.10). Gene expression of EGF in milk fat globules tended to be (LACT1, P < 0.10) or was increased (LACT3, P < 0.05) after treatment, and the effect in LACT1 sows was maintained until d 21 of lactation. The mRNA abundance of SPP1 was increased (P < 0.05) in LACT1 vs CTL sows on d 7, and that of 3 major milk proteins tended to be (CSN1S2 and WAP, P < 0.10) or was greater (LALBA, P < 0.05) in LACT3 vs CTL sows on d 21 of lactation. Oral administration of domperidone during the first or third week of lactation increased prolactin concentrations and altered mRNA abundances of selected genes in milk fat globules. Yet, only the LACT 3 treatment positively affected piglet performance.

Effects of sustained hyperprolactinemia in late gestation on the mammary parenchymal tissue transcriptome of gilts

BACKGROUND

Gilts experiencing sustained hyperprolactinemia from d 90 to 109 of gestation showed an early onset of lactogenesis coupled with premature mammary involution. To better understand the molecular mechanisms underlying the premature mammary involution observed in these gilts, a transcriptomic analysis was undertaken. Therefore, this study aimed to explore the effect of hyperprolactinemia on the global transcriptome in the mammary tissue of late gestating gilts and identify the molecular pathways involved in triggering premature mammary involution.

METHODS

On d 90 of gestation, gilts received daily injections of (1) canola oil until d 109 ± 1 of gestation (CTL, n = 18); (2) domperidone (to induce hyperprolactinemia) until d 96 ± 1 of gestation (T7, n = 17) or; (3) domperidone (until d 109 ± 1 of gestation (T20, n = 17). Mammary tissue was collected on d 110 of gestation and total RNA was isolated from six CTL and six T20 gilts for microarray analysis. The GeneChip® Porcine Gene 1.0 ST Array was used for hybridization. Functional enrichment analyses were performed to explore the biological significance of differentially expressed genes, using the DAVID bioinformatics resource.

RESULTS

The expression of 335 genes was up-regulated and that of 505 genes down-regulated in the mammary tissue of T20 vs CTL gilts. Biological process GO terms and KEGG pathways enriched in T20 vs CTL gilts reflected the concurrent premature lactogenesis and mammary involution. When looking at individual genes, it appears that mammary cells from T20 gilts can simultaneously upregulate the transcription of milk proteins such as WAP, CSN1S2 and LALBA, and genes triggering mammary involution such as STAT3, OSMR and IL6R. The down-regulation of PRLR expression and up-regulation of genes known to inactivate the JAK-STAT5 pathway (CISH, PTPN6) suggest the presence of a negative feedback loop trying to counteract the effects of hyperprolactinemia.

CONCLUSIONS

Genes and pathways identified in this study suggest that sustained hyperprolactinemia during late-pregnancy, in the absence of suckling piglets, sends conflicting pro-survival and cell death signals to mammary epithelial cells. Reception of these signals results in a mammary gland that can simultaneously synthesize milk proteins and initiate mammary involution.

Dietary supplementation with lysine (protein) in late pregnancy does not enhance mammary development in multiparous sows

This project was conducted to determine if providing standardized ileal digestible (SID) Lys at 40% above estimated requirements (NRC, 2012), with the concomitant increased protein intake, from days 90 to 110 of gestation stimulates mammary development in multiparous sows. From day 90 of gestation, Yorkshire × Landrace multiparous sows (parities 2 and 3) were fed 2.6 kg/d of either a conventional diet (CTL, control, n = 17) providing 14.8 g/d of SID Lys or a diet providing 20.8 g/d of SID Lys via additional soybean meal (HILYS, n = 16). The diets were isoenergetic. Concentrations of IGF-1, glucose, free fatty acids (FFA), urea, and amino acids (AA) were measured in jugular blood samples obtained on days 90 and 110 of gestation. Sows were necropsied on day 110 ± 1 of gestation to obtain mammary glands for compositional and histological analyses. Backfat or BW changes of sows during late gestation were unaffected by treatment (P > 0.10), as was the case for fetal BW (P > 0.10). None of the variables measured in mammary tissue were altered by supplementary Lys (P > 0.10). Circulating IGF-1, glucose, and FFA did not differ (P > 0.10) between HILYS and CTL sows on day 110 of gestation, whereas concentrations of urea were greater (P < 0.01) in HILYS versus CTL gilts. Concentrations of Ile and Thr in plasma were also greater (P < 0.05), and those of Glu were lower (P < 0.01) in HILYS than CTL sows. These results demonstrate that feeding Lys (via protein) above current NRC recommendations during late gestation does not improve mammary development of multiparous sows. Hence, the use of a two-phase feeding strategy to provide more Lys (protein) to multiparous sows during this period is not necessary.

The effect of moderate energy and protein restriction during gilt development on changes in body weight and backfat depth and subsequent lactation performance

Eighty-eight gilts [initial body weight (BW) 49.8 ± 0.8 kg] were recruited to determine the effects of moderate energy and protein restriction during the development period on changes in BW and backfat depth (BF) and subsequent lactation performance. Gilts were randomly assigned to one of four feeding programs: 1) standard commercial diet fed ad libitum (CON), 2) standard commercial diet fed 10% or 3) 20% below ad libitum, or 4) a high-fiber diet fed ad libitum [2.5 times more fiber (neutral detergent fiber) than the commercial diet to dilute net energy and crude protein by approximately 20% and 13%, respectively; FIB]. The gilts were housed individually and received the feeding programs between 90 and 190 (breeding) d of age and standard gestation and lactation diets thereafter. Litters were standardized to 12 ± 1 pigs within 48 h of farrowing; weaning occurred at 20.0 ± 0.4 d of age. Gilts that received the 20% restricted program had lower overall average daily feed intake (ADFI) during the development period (2.64 ± 0.04 kg; P < 0.05) versus all other feeding programs and gilts that received the 10% restricted program had lower ADFI than FIB and CON, which were not different (2.96 vs. 3.44 and 3.47 ± 0.04 kg for 10%, FIB and CON, respectively; P < 0.05). Plasma free fatty acid (FFA) concentrations on day 180 of age were lower for gilts that received the 10% and 20% restricted programs compared to gilts that received the FIB and CON programs, which were not different (97 and 86 vs. 220 and 149 ± 29 µEq/L, respectively; P < 0.05). Plasma concentrations of glucose, urea, prolactin, and IGF-1 were not different among feeding programs on day 180 of age. At breeding, gilts that received the FIB and 10% programs had lower BW and BF versus CON (145.7 and 144.8 vs. 155.2 ± 0.9 kg and 14.4 and 14.8 vs. 16.5 ± 0.2 mm for BW and BF, respectively; P < 0.05) but greater BW than gilts that received the 20% restricted program (137.9 kg; P < 0.05). The BW and BF of gilts did not differ at the end of gestation or at weaning. The ADFI of sows during lactation and offspring birth weight and growth rate during lactation and the 5-wk nursery period were not influenced by gilt development feeding program. Therefore, a high-fiber feeding program could be used in group-housing gilt-development scenarios, where feed is offered ad libitum, to control BW and BF prior to breeding without influencing milk production in the subsequent lactation period.

Exogenous porcine somatotropin administered to late pregnant gilts alters liver and muscle functionalities in pig foetuses

Neonatal maturity depends on the maternal capacity to provide nutrients for foetal growth. This study aimed to investigate the effects of systemic administration of recombinant porcine somatotropin (pST), one of the main regulators of growth and metabolism, to pregnant gilts during late gestation on circulating nutrients and expression levels of genes in liver and skeletal muscle of their 110-day-old foetuses. Gilts received either daily injections of sterile water (control [CTL] group, n = 15) or of 5 mg of pST (pST group, n = 17) from days 90 to 109 of gestation. At day 110 postconceptus, pairs of foetuses (one of small and one of average size within a litter) were selected. Circulating fructose concentrations were greater, but circulating concentrations of urea were lower in pST than in CTL foetuses. Expression levels of genes involved in carbohydrate and lipid metabolism were more affected by pST treatment in liver than in muscle. Hepatic molecular changes suggest an inhibition of energy-consuming processes (glycogen and lipid biosynthesis) and the activation of energy-producing pathway (mitochondrial oxidation) in pST compared to CTL foetuses. Expression levels of some genes involved in intracellular degradation of proteins were greater in the liver of pST foetuses, and combined with lower uremia, this suggests a higher utilisation of protein sources in pST foetuses than in CTL foetuses. In muscle, molecular changes were mainly observed in the IGF-insulin axis. Altogether, pST-treated gilts seem to have a greater ability to support foetal liver development by the reorientation of energy and protein metabolism.

Review: Physiology and nutrition of late gestating and transition sows

The physiology during late gestation and the transition period to lactation changes dramatically in the sow, especially during the latter period. Understanding the physiological processes and how they change dynamically as the sow approaches farrowing, nest building, giving birth to piglets, and producing colostrum is important because these processes greatly affect sow productivity. Glucose originating from assimilated starch accounts for the majority of dietary energy, and around farrowing, various organs and peripheral tissues compete for plasma glucose, which may become depleted. Indeed, physical activity increases shortly prior to farrowing, leading to glucose use by muscles. Approximately ½ to 1 d later, glucose is also needed for uterine contractions to expel the piglets and for the mammary gland to produce lactose and fat for colostrum. At farrowing, the sow appears to prioritize glucose to the mammary gland above the uterus, whereby insufficient dietary energy may compromise the farrowing process. At this time, energy metabolism in the uterus shifts dramatically from relying mainly on the oxidation of glucogenic energy substrates (primarily glucose) to ketogenic energy supplied from triglycerides. The rapid growth of mammary tissue occurs in the last third of gestation, and it accelerates as the sow approaches farrowing. In the last 1 to 2 wk prepartum, some fat may be produced in the mammary glands and stored to be secreted in either colostrum or transient milk. During the first 6 h after the onset of farrowing, the uptake of glucose and lactate by the mammary glands roughly doubles. Lactate is supplying approximately 15% of the glucogenic carbon taken up by the mammary glands and originates from the strong uterine contractions. Thereafter, the mammary uptake of glucose and lactate declines, which suggests that the amount of colostrum secreted starts to decrease at that time. Optimal nutrition of sows during late gestation and the transition period should focus on mammary development, farrowing performance, and colostrum production. The birth weight of piglets seems to be only slightly responsive to maternal nutrition in gilts; on the other hand, sows will counterbalance insufficient feed or nutrient intake by increasing mobilization of their body reserves. Ensuring sufficient energy to sows around farrowing is crucial and may be achieved via adequate feed supply, at least three daily meals, high dietary fiber content, and extra supplementation of energy.

Review: Improving the performance of neonatal piglets

Newborn piglets have a high incidence of preweaning mortality that is not only associated with low birth weights but also with the presence of intra-uterine growth-restricted (IUGR) piglets. Such IUGR piglets are commonly seen in litters from hyperprolific sows as a result of insufficient placental transfer of nutrients. Nutritional strategies can be used prior to and during gestation to enhance foetal development and can also be implemented in the transition period to reduce the duration of farrowing and increase colostrum yield. Recent findings showed that the energy status of sows at the onset of farrowing is crucial to diminish stillbirth rate. Newborn piglets often fail to consume enough colostrum to promote thermostability and subsequent growth, and this is particularly problematic in very large litters when there are fewer available teats than the number of suckling piglets. One injection of 75 IU of oxytocin approximately 14 h after farrowing can prolong the colostral phase, hence increasing the supply of immunoglobulins to piglets. Nevertheless, assistance must be provided to piglets after birth in order to increase their chance of survival. Various approaches can be used, such as: (1) optimising the farrowing environment, (2) supervising farrowing and assisting newborn piglets, (3) using cross-fostering techniques, (4) providing nurse sows, and 5) providing artificial milk. Although research advances have been made in developing feeding and management strategies for sows that increase performance of their newborn piglets, much work still remains to be done to ensure that maximal outcomes are achieved.

PSVII-9 The Impact of Increasing Dietary Manganese on the Reproductive Performance of Sows

The objective of this study was to determine the effect of dietary manganese (ProPath Mn, Zinpro Corporation) on the reproductive performance of sows. Sows (N = 39; 231 ± 8 kg) were randomly assigned to 1 of three dietary levels of Mn (CON: 0 ppm Mn; PRO20: 20 ppm Mn; PRO40: 40 ppm Mn). Experimental treatments were initiated at breeding and continued through 2 parities. Sows were blocked by parity within each farrowing group and dietary treatments were represented within each block. Data were analyzed as a randomized complete block design using the MIXED procedure of SAS with diet as a fixed effect and block as a random effect. Dietary treatment did not affect sow body weights (P &gt; 0.10). Lactation feed intake was increased in PRO20 sows compared with CON and PRO40 sows (P &lt; 0.05). PRO20 and PRO40 sows farrowed heavier piglets (CON 1.23 kg; PRO20 1.57 kg; PRO40 1.40 kg; P = 0.001) with improved average daily gain to weaning (CON 213 g/day; PRO20 237 g/day; 220 g/day; P &lt; 0.05), compared with CON sows. Milk fat content (average from d 7 and 14 of lactation) was reduced in PRO20 (5.5%) and PRO40 sows (6.1%; P &lt; 0.05) compared with CON sows (7.8%), possibly due to increased milk demand from the piglets. There were no significant differences in milk mineral concentrations during lactation or piglet tissue Mn-superoxide dismutase (MnSOD) activity at weaning (P &gt; 0.10). On day 3 of lactation, prolactin concentrations were similar across treatments (P &gt; 0.10), whereas progesterone concentrations tended to differ in response to Mn level (CON 23.70 ng/mL; PRO20 26.15 ng/mL; PRO40 22.10 ng/ml; P = 0.09). Supplementary dietary Mn throughout 2 gestation and lactation cycles led to increased birth weights and pre-weaning growth of piglets.

Dietary supplementation with lysine (protein) stimulates mammary development in late pregnant gilts

The goal of this project was to determine if standardized ileal digestible (SID) lysine provided at 40% above estimated requirements, with the concomitant increase in protein intake, from days 90 to 110 of gestation would stimulate mammary development in gilts. From day 90 of gestation, Yorkshire × Landrace gilts were fed 2.65 kg of either a conventional diet (CTL, control, n = 19) providing 18.6 g/d of SID Lys or a diet providing 26.0 g/d of SID Lys via additional soybean meal (HILYS, n = 19). Both diets were isoenergetic. Jugular blood samples obtained on days 90 and 110 of gestation were used to measure concentrations of insulin-like growth factor-1 (IGF-1), metabolites, and amino acids (AA). Gilts were necropsied on day 110 ± 1 of gestation to obtain mammary glands for compositional analyses, immunohistochemistry, and analysis of mRNA abundance for AA transporters and markers of cell proliferation and differentiation. The HILYS gilts gained more body weight (P < 0.01) during the experimental period compared with CTL gilts, and had greater fetal weights (1.29 vs. 1.21 ± 0.03 kg, P < 0.05). There was no difference in circulating IGF-1, glucose, or albumin (P > 0.10) between HILYS and CTL gilts on day 110 of gestation, whereas concentrations of urea and free fatty acids were greater (P < 0.01), and those of Trp and Ala were lower (P < 0.05), in HILYS than CTL gilts. The provision of lysine at 40% above estimated requirements increased total mammary parenchymal mass by 44%, as well as total parenchymal fat, protein, DNA, and RNA (P < 0.01). The mRNA abundance of ACACA was greater (P < 0.05) in HILYS than CTL gilts, while only the AA transporter SLC6A14 tended (P < 0.10) to be greater. Results demonstrate that providing dietary Lys above current National Research Council recommendations in late gestation increases mammary development in gilts. Results also indicate that Lys may have been limiting for protein retention. These data suggest that the use of a two-phase feeding strategy during gestation, whereby dietary Lys is increased from day 90, could benefit potential sow milk yield in the subsequent lactation.

Prolactin and the swine mammary gland

Prolactin is a hormone that is most important for mammary development in swine. It is also essential for both the onset and the maintenance of lactation. In early studies, exogenous recombinant porcine prolactin was used to detect its biological effects on mammary tissue. In these studies, a stimulatory role of prolactin for mammary development of prepubertal gilts was demonstrated. However, when injected throughout lactation, prolactin did not increase sow milk yield likely because mammary receptors were saturated. The secretion of prolactin is largely under negative regulation via dopamine. Inhibition studies using the dopamine agonist bromocriptine showed that prolactin is required in the last third of gestation to sustain mammary development in gilts. When creating a hyperprolactinemic state during that same period, with the dopamine antagonist domperidone, differentiation of mammary epithelial cells was stimulated and milk yield in the subsequent lactation was increased. Domperidone given throughout lactation also led to greater milk yield. A study using domperidone in prepubertal gilts, however, did not reproduce the stimulatory effect of exogenous prolactin on mammary development and demonstrated that timing of the prolactin increase in relation to age of the animals is most important to elicit a response on mammary tissue. Attempts were made to use feed ingredients such as the plant extract from milk thistle, sylimarin, to stimulate prolactin secretion in sows. However, even though prolactin concentrations were increased, this augmentation was not important enough to have an impact on mammary development in late gestation or to increase milk yield. The current knowledge that hyperprolactinemia has beneficial effects for mammary development at various physiological stages and can enhance milk yield in swine leads to new avenues in elaborating strategies that could be used at the farm level to improve sow lactation performance.

Providing domperidone throughout lactation enhances sow lactation performance

The goal of this project was to determine the effects of domperidone given throughout lactation on hormonal and metabolic status, lactational performance, and gene expression in mammary epithelial cells of sows. Second parity sows were divided in two treatment groups: 1) daily intramuscular injections with canola oil (Control, CTL, n = 24), or 2) daily intramuscular injections with 0.5 mg/kg body weight (BW) of domperidone (DOMP, n = 23). Injections were given at 08h05 starting the day after farrowing until weaning. Over the first 4 d of treatment, DOMP sows also received 0.5 mg/kg BW of domperidone per os twice daily, whereas CTL sows were fed the vehicle. Litter size was standardized to 11 ± 1 within 24 h of birth and piglets were weighed at birth, 24 h postpartum, and on days 7, 22 (weaning on day 23), 35, and 56. Sow feed intake was recorded daily. Representative milk samples were obtained aseptically on day 21 of lactation from 15 sows per treatment for compositional analyses and milk fat globules were used to measure mRNA abundances of various genes. Jugular blood samples were obtained from all sows on days 2, 8, 16, and 23 of lactation to measure concentrations of prolactin, insulin-like growth factor-1 (IGF-1), leptin, adiponectin, insulin, glucose, urea, and free fatty acids (FFA). Concentrations of prolactin (P < 0.001) and FFA (P < 0.01) were increased in DOMP compared with CTL sows, whereas concentrations of insulin were decreased (P < 0.05). Urea concentrations were increased by treatment (P < 0.05) on days 16 and 23 of lactation, and those of IGF-1 were increased (P < 0.01) on day 16. Piglets from DOMP sows were heavier than those from CTL sows on day 22 (P < 0.01). Milk composition was unaffected by treatment. The mRNA abundance in milk fat globules for casein beta and whey acidic protein were lower (P ≤ 0.05) in DOMP than CTL sows. The long form of the prolactin receptor and the signal transducer and activator of transcription 5A mRNA abundances tended to be lower (P < 0.10) in DOMP than CTL sows. In conclusion, hyperprolactinemia induced by domperidone during lactation affected the endocrine and metabolite status of sows and stimulated growth of their suckling piglets.

Hyperprolactinemia using domperidone in prepubertal gilts: Effects on hormonal status, mammary development and mammary and pituitary gene expression

Objectives of this experiment were to determine if the domperidone protocol previously used for gestating gilts can also lead to hyperprolactinemia in growing gilts, and to assess the effects of such a protocol on hormonal status, mammary development and gene expression in mammary and pituitary tissue of gilts at puberty. The impact on future lactation performance was also determined. At 75 ± 3 kg body weight (BW), gilts were divided between: 1) controls (CTL), receiving daily intramuscular (IM) injections of canola oil (1.1 mL) for 29 d (n = 41), and 2) treated (DOMP), receiving daily IM injections with 0.5 mg/kg BW of the dopamine receptor antagonist domperidone for 29 d (n = 40). In addition to that daily injection, treated gilts also received twice daily IM injections with 0.5 mg/kg BW of domperidone over the first 3 d of treatment. Fifteen gilts per treatment were sacrificed at 210 ± 5 d of age to collect mammary glands (for compositional analysis and gene expression) and the anterior pituitary (for gene expression). Remaining gilts were bred and allowed to farrow. Blood was sampled at the onset of treatment and on days 14 and 30. Gilts that farrowed were also blood sampled on days 3 and 20 of lactation. Blood was assayed for prolactin (PRL), leptin, insulin-like growth factor 1 (IGF-1), urea, free fatty acids and glucose. Concentrations of PRL increased after 14 d and 30 d of treatment (P < 0.01) and were lesser on day 3 of lactation in DOMP than CTL gilts (P < 0.01). At puberty, there were tendencies (P < 0.10) for total parenchymal protein and DNA to be greater in DOMP than CTL gilts. Treatment did not affect mRNA abundance of PRL or the long form of the PRL receptor genes in the pituitary gland at puberty but expression level of the dopamine receptor D2 and PRL genes was much lower in pubertal than late-pregnant gilts (P < 0.001). Furthermore, many genes related with PRL had a much greater expression level in late pregnancy than at puberty. On day 20 of lactation, CTL sows had greater concentrations of urea than DOMP sows (P < 0.01). The growth rate of litters was not affected by treatment nor was milk composition (P > 0.10). Even though PRL concentrations were increased with treatment, the absence of effect on mammary development was either due to timing relative to developmental stage, whereby treatment was initiated when gilts were too young, or was because all PRL receptors may have been saturated thereby preventing biological action of additional PRL.

Impact of arginine supplementation on serum prolactin and mRNA abundance of amino acid transporter genes in mammary tissue of lactating sows

This study was conducted to test the hypothesis that supplemental dietary Arg to late-pregnant and lactating sows increases serum prolactin concentrations and mRNA abundance of SLC7A1, SLC7A2, and SLC6A14 in mammary parenchymal tissue. From day 108 of gestation and until day 21 of lactation, sows were fed a diet either supplemented with 0.10 g of l-Arg/kg body weight (BW) per day (n = 10, ARG) or 0.34 g of l-Glu/kg BW per day (n = 10, control). Litters were standardized to 10 piglets on day 1 of lactation and piglets were weighed on days 1, 7, 14, and 21 of lactation. Sow BW was recorded on day 108 of gestation and days 1, 10, and 21 of lactation. Lactation sow feed intake was recorded daily. Mammary parenchymal tissue was biopsied on day 5 of lactation to measure mRNA abundance SLC7A1, SLC7A2, and SLC6A14. On days 4 and 18 of lactation, blood samples were collected from sows at 2, 4, and 6 hr postfeeding to measure serum prolactin concentrations. Milk samples were collected on days 4, 10, and 18 of lactation to measure fat, lactose, urea N, and true protein concentrations. Sow BW, backfat, and feed intake over all sampling days did not differ between treatments. Piglet BW on d 1 tended to be greater for the ARG treatment than the control treatment (P = 0.12). Sow milk yield and composition (fat, protein, lactose, and urea N) and mammary mRNA abundance of candidate genes did not differ between the ARG and the control group. Compared to controls, serum prolactin concentrations tended to be greater (P = 0.08) in ARG sows on day 4 of lactation, and did not differ on day 18. Current findings show a potential beneficial effect of dietary supplementation with Arg to late-pregnant multiparous sows on BW of their piglets on day 1. Dietary Arg supplementation at a rate of 0.10 g/kg BW during late pregnancy and lactation tended to increase serum prolactin concentrations with no increase in mammary transcript abundance of SLC7A1, SLC7A2, and SLC6A14 in early lactation.

Metoclopramide induces preparturient, low-level hyperprolactinemia to increase milk production in primiparous sows

Inadequate milk production by sows often limits the growth of piglets. A successful lactation requires prolactin (PRL)-induced differentiation of the alveolar epithelium within the mammary glands of sows between days 90-110 of gestation. We hypothesized that induction of late gestational hyperprolactinemia in primiparous sows by oral administration of the dopamine antagonist metoclopramide (MET) would enhance mammary epithelial differentiation, milk yield, and piglet growth rate and that these effects would carry over into a subsequent lactation. Twenty-six gilts were assigned to receive either MET (n = 13, 0.8 mg/kg) or vehicle (CON, n = 13) twice daily from days 90-110 of gestation. The same sows were followed into their second lactation without additional treatment. On day 90 of gestation, circulating PRL concentrations peaked 45 min after feeding MET (P < 0.001) and then returned to baseline 3 h later. This response occurred daily out to day 104 of gestation (P < 0.05). Compared with CON, MET-treated gilts had enlarged alveoli on gestation day 110 (P < 0.05). Treatment with MET did not affect feed intake, body weight, or body fatness during pregnancy or lactation. Piglets born to MET-treated sows had both increased body weights and average daily gain on lactation days 14 and 21 (P < 0.05). Milk intake by piglets was estimated from deuterium oxide dilution. Although milk intake by piglets nursing MET sows was not statistically different from those nursing CON sows on day 21 of lactation (P = 0.18), there was a greater increase in milk consumption by piglets born to MET-treated sows between days 9 and 21 of lactation than for those in CON litters (P < 0.001). In one group of second parity sows (n = 11) that were treated with MET during their first gestation, milk yield increased by 21% during their second lactation (P < 0.05) in association with a 14% decline in body fatness across lactation compared with a 7% decline in CON sows (P < 0.05). These findings demonstrate that MET-induced hyperprolactinemia in primiparous sows during late pregnancy can increase milk yield and piglet growth rate, setting the stage for further large-scale studies.

COVID-19 in Kidney Transplant Patients From a Large UK Transplant Center: Exploring Risk Factors for Disease Severity

Background

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has raised concern for the health of immunocompromised individuals, who are potentially at higher risk of more severe infection and poorer outcomes. As a large London transplant center serving a diverse patient population, we report the outcomes of SARS-CoV-2 infection in our cohort of 2848 kidney and/or pancreas transplant patients.

Methods

Data were obtained retrospectively for all transplant patients who attended hospital during the peak of the pandemic and had a positive nasopharyngeal SARS-CoV-2 test.

Results

Sixty-six patients were found to be positive for SARS-CoV-2. Twenty percent were treated as outpatients, 59% were admitted to the general ward, and 21% required intensive care. Treatment consisted of reduced immunosuppression, antibiotics for pneumonia or sepsis, and other supportive treatments. Within our cohort, 12 patients died (18%), with an overall mortality of 0.4%. Predictive risk factors for COVID-19 severity were explored.

Conclusions

Severe disease was associated with lower hemoglobin prior to COVID-19 diagnosis and lower lymphocyte count at the time of diagnosis but not age, sex, ethnicity, or preexisting comorbidities. Lower glomerular filtration rate and higher C-reactive protein were associated with more severe disease. Despite no use of hydroxychloroquine, azithromycin, antiviral, or immunomodulatory medications, our mortality rate (kidney and pancreas transplant patients) is similar to current international rates.

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.

244 The effect of a high-fiber feeding program for replacement gilts on body weight and composition at breeding

Sixty-three gilts were recruited at 90 days of age to evaluate the effects of a high-fiber gilt development feeding program on body weight and composition at breeding. Gilts (initial BW 50.9 ± 0.9 kg) were housed individually and randomly attributed to one of four feeding programs: [1] commercial diet fed ad libitum (CON), [2] commercial diet fed 10%, or [3] 20% below ad libitum, and [4] a high-fiber diet fed ad libitum (25% more fiber than the commercial diet and energy density reduced by 5%; FIB). Gilts received the feeding program between 90 days of age and breeding at ~190 days of age. Body weight and feed disappearance were determined weekly. Backfat depth was determined at 90, 145 (puberty), 160, and 190 (breeding) days of age. Over the entire experimental period, CON and FIB gilts had greater ADFI (mean of 3.50 ±0.07 kg) compared to 10% (2.95 ± 0.06 kg) and 20% gilts (2.70 ± 0.07kg; P &lt; 0.05). The FIB feeding program reduced total energy and lysine intakes to amounts similar to 10%; both intakes were less than CON but greater than 20% gilts (P &lt; 0.05). The ADG of FIB was less between days 145 (puberty) and 160 of age compared to CON gilts (0.86 vs. 1.09 ± 0.07 kg; P &lt; 0.05). At breeding, FIB and 10% weighed less (146.5 ± 1.6 kg) than CON (152.7 ± 1.6 kg) and more than 20% gilts (138.7 ± 1.5 kg; P &lt; 0.05). The FIB had less backfat than CON at breeding (14.9 vs. 16.7 ± 0.5 mm; P &lt; 0.05), but did not differ from 10% or 20% gilts. In conclusion, the FIB feeding program limited energy intake, growth, and body fatness of gilts at breeding, even though gilts were offered feed ad libitum. Therefore, high-fiber feeding programs could be a practical means to control growth rates of developing gilts in commercial scenarios.

241 Metoclopramide induces low-level hyperprolactinemia to increase milk production in sows

Inadequate milk production by sows often limits the growth rate of piglets. A successful lactation requires prolactin (PRL)-induced differentiation of the alveolar epithelium within the mammary glands of sows between gestation days 90–110 (G90-110). We hypothesized that late gestational hyperprolactinemia in primiparous sows induced by feeding the dopamine antagonist metoclopramide (MET) would enhance mammary epithelial differentiation, milk yield, and piglet growth rate, and that these effects would carry over into a subsequent lactation. Twenty-six gilts were randomly assigned to receive either MET (n = 13, 0.8mg/kg) or vehicle (CON, n = 13) twice daily from G90-110. On G90, circulating PRL levels peaked 45 min after MET dosing (P &lt; 0.001) then returned to baseline 3 h later. This response occurred daily out to G104 (P &lt; 0.05). Treated gilts had increased alveolar lumen diameter on G110 (P &lt; 0.05), though feed intake, body weight, and carcass fat percent were not different during pregnancy or lactation. Piglets born to treated sows had increased body weight and average daily gain on lactation days 14 and 21 (P &lt; 0.05). Piglet milk intake was estimated from deuterium oxide dilution. While milk intake by piglets nursing MET sows was not statistically different from those nursing CON sows on day 21 of lactation (P = 0.18), there was a greater increase in milk consumption by piglets born to MET-treated sows between days 9 and 21 of lactation than for those in CON litters (P &lt; 0.001). In one group of second parity sows, milk yield was increased during their second lactation with no additional treatment (P &lt; 0.05) and their carcass fat dropped by 14% (P &lt; 0.05). These findings demonstrate that MET-induced hyperprolactinemia in pigs during late pregnancy can increase milk yield and piglet growth rate, and this response can be sustained into a second lactation in some sows.

Effects of sustained hyperprolactinemia in late gestation on mammary development of gilts

The objective of this project was to determine the effects of sustained hyperprolactinemia for 7 or 20 d on mammary development in late-pregnant gilts. On day 90 of gestation, gilts were assigned to one of 3 groups to receive intramuscular (IM) injections of (1) canola oil (CTL, n = 18) until day 109 ± 1 of gestation; (2) a dopamine receptor antagonist, domperidone (0.5 mg/kg of body weight [BW]) until day 96 ± 1 of gestation (T7, n = 17); or (3) domperidone (0.5 mg/kg BW) until day 109 ± 1 of gestation (T20, n = 17). Domperidone-treated gilts also received 100 mg of domperidone per os twice daily from days 90 to 93 of gestation. Blood was sampled on days 89, 97, 104, and 110 for prolactin (PRL), insulin-like growth factor 1 (IGF1), lactose, urea, and glucose assays. Mammary glands were collected at necropsy, on day 110, for compositional and cell proliferation analyses. Abundance of mRNA for selected genes was also determined in the mammary gland and the pituitary gland. On day 97 of gestation, PRL concentrations were 3 times greater for T20 and T7 than CTL gilts and were also greater for T20 than T7 and CTL gilts on days 104 and 110 (P < 0.001). Concentrations of IGF1 in T20 and T7 gilts were elevated relative to controls on days 97 and 104 and were greater for T20 vs T7 and CTL gilts on day 110 (P < 0.05). There were no treatment effects (P > 0.1) on parenchymal or extraparenchymal tissue weights, or on epithelial proliferation as measured by immunohistochemistry for Ki-67. Treatments did not alter concentrations of dry matter (DM), fat, or DNA (P > 0.1) in parenchyma. Concentrations of RNA (P < 0.05) and protein (P < 0.10) as well as total parenchymal protein, RNA, and DNA (P < 0.05) were lower, or tended to be, in T20 than T7 or CTL gilts. Hyperprolactinemia for 20 d in late gestation increased mRNA abundance of the milk protein genes beta-casein (CSN2) and whey acidic protein (WAP) (P < 0.05) in mammary parenchyma and also decreased mRNA abundance of the long form of the prolactin receptor (PRLR-LF). Increasing PRL concentrations for 7 or 20 d in late gestation had no beneficial effects on the composition of the mammary gland, and sustained exposure to domperidone for 20 d reduced metabolic activity either by a lower expression of the long form of the PRL receptor in mammary parenchymal tissue or, most likely, by the early involution of parenchymal tissue. In conclusion, results do not support the hypothesis that a sustained hyperprolactinemia in late gestation could enhance mammary development of gilts.

Concordance of the Vineland Adaptive Behavior Scales, second and third editions

BACKGROUND

Because of its centrality in the conceptualization of intellectual disability, reliable and valid measurement of adaptive behaviour is important to both research and clinical practice. The manual of the Vineland Adaptive Behavior Scales, recently released in its third edition, provides limited reliability information obtained from a sample composed primarily of typically developing individuals. The goal of this study was to evaluate the concordance of the Vineland-3 with the Vineland-II in a sample more similar in ability level to those in which the Vineland is commonly used.

METHODS

Both editions of the Vineland Interviews were conducted with a convenience sample of 106 parents/caregivers of individuals with neurodevelopmental disability, participating at two neurodevelopmental disorder research clinics. Administrations were up to 7 days apart, but most (90%) were simultaneous. The concordance correlation coefficient (CCC) (95% confidence interval) and mean differences (95% confidence interval) were calculated for domain standard scores and subdomain v-scale scores.

RESULTS

Domain-level CCC ranged from 0.78 [0.70, 0.84] (Communication) to 0.86 [0.76, 0.92] (Motor). Subdomain CCC ranged from 0.71 [0.62, 0.78] (Receptive Language) to 0.91 [0.85, 0.95] (Fine Motor). Vineland-3 scores were lower than Vineland-II scores; 77% of participants had lower Adaptive Behavior Composite scores on the Vineland-3 than on the Vineland-II. For the subdomains, the magnitude of this difference depended upon the level of adaptive behaviour. For Communication, the domain with the lowest CCC, the mean difference ranged from -13.70 [-8.03, -19.35] for a Vineland-II score or 85 to a difference of -19.18 [-12.28, -26.87] for a Vineland-II score of 40.

DISCUSSION

Amongst individuals with intellectual and developmental disabilities, the Vineland-3 produces lower scores than the Vineland-II, and these clinically significant differences tend to be larger for individuals with lower levels of ability. Thus, care must be taken in interpreting scores from the Vineland-3 relative to those obtained from the previous edition.

Effects of supplementing processed straw during late gestation on sow physiology, lactation feed intake, and offspring body weight and carcass quality1

This study investigated the effects of supplementing late gestation sow diets with processed or unprocessed oat or wheat straw on physiology, early lactation feed intake, and offspring performance. One hundred fifty gestating sows were randomly assigned to 1 of 5 dietary treatments (30 sows per diet) from day 86 of gestation until farrowing. Treatments, arranged as a 2 × 2 factorial plus a control, were a standard gestation diet (control) or control supplemented with 10% wheat or oat straw, processed or unprocessed. Sows were fed a standard lactation diet postfarrowing. The processed straws were produced by high-pressure compaction at 80 °C. On day 101 of gestation (day 15 of the trial), blood samples were collected from a subset of sows (n = 8 per treatment) through ear vein catheters and analyzed for insulin, insulin-like growth factor 1 (IGF-1), prolactin, glucose, and urea concentrations. Fecal samples were collected on days 103 to 104 of gestation to determine nutrient digestibility, and feeding motivation was investigated on day 104. Litter characteristics and sow feed intake were recorded for 7 d postfarrowing. Three piglets per litter were selected at weaning, fed standard diets, and followed to market. Treatment had no effect on feeding motivation, piglet characteristics at birth, estimated milk production, and offspring BW at market or carcass quality. Processed straw improved DM digestibility and energy content and the effect was greater with oat straw (straw × processing effect, P < 0.05). Pre- and postprandial glucose concentrations tended to decrease (P < 0.10) with processing of wheat, but not oat straw, and this effect was more apparent in the preprandial samples. Preprandial prolactin concentration increased with oat but decreased with wheat straw, whereas postprandial IGF-1 and prolactin concentration increased with processing of wheat, but not oat straw (straw × processing, P < 0.05). Sow lactation feed intake improved (P < 0.05) with oat straw supplementation relative to wheat straw. Piglet weaning weight increased (P < 0.05) with oat straw supplementation and processing improved (P < 0.05) nursery exit BW. However, straw supplementation, regardless of processing, had no effect on offspring BW at market or carcass quality. Overall, oat straw supplementation had a greater impact on sow physiology and provided benefits for sows in late gestation, and there was some indication that further benefits could be obtained through mild processing.

PSI-7 Effects of sustained hyperprolactinemia in late gestation on mammary development of gilts

This project sought to determine the effects of sustained hyperprolactinemia on mammary development in late-pregnant gilts. Gilts were divided into 3 groups on day 90 of gestation to receive i.m. injections of: 1) canola oil (CTL, n = 18) until day 109 of gestation, 2) domperidone (dopamine receptor antagonist) until day 96 (T7, n = 17) or, 3) domperidone until day 109 (T20, n = 17). Treated gilts also received domperidone orally from days 90 to 93. Blood was sampled on days 97 and 110 for prolactin and IGF-1 assays. Mammary glands were collected at necropsy on day 110 for compositional and cell proliferation analyses. The MIXED procedure of SAS was used for statistical analyses. On day 97 of gestation, prolactin concentrations were greater for T20 and T7 than CTL gilts (19.0, 18.9 and 6.0 ± 1.6 ng/mL, respectively, P &lt; 0.001), and were also greater for T20 than T7 and CTL gilts on day 110 (21.7, 8.9 and 10.0 ± 1.5 ng/mL, respectively, P &lt; 0.001). Concentrations of IGF-1 were greater for T7 and T20 than CTL gilts on day 97, and were greater for T20 vs T7 and CTL gilts on day 110 (P &lt; 0.05). There were no effects of treatment (P &gt; 0.1) on parenchymal or extraparenchymal tissue weights, or on cellular proliferation by immunohistochemistry for Ki67. Treatments did not alter concentrations of DM, fat or DNA (P &gt; 0.1) in parenchyma, while concentrations of protein (P &lt; 0.01) and RNA (P &lt; 0.05) as well as total protein, RNA and DNA in parenchyma (P &lt; 0.05) were lower in T20 than T7 or CTL gilts. Increasing prolactin concentrations for 7 or 20 d in late gestation had no beneficial effects on mammary composition, where sustained exposure for 20 d reduced metabolic activity.

431 Increasing IGF-1 concentrations in late pregnancy stimulates mammary development of gilts

The goal of this project was to determine if increasing insulin-like growth factor-1 (IGF-1) concentrations in late pregnancy can stimulate mammogenesis in gilts. Yorkshire x Landrace gilts (196.2 ± 6.2 kg BW on day 89 of gestation) were separated in two groups: 1) controls (CTL, n = 17) injected with sterile water, and 2) porcine somatotropin-treated (pST, n = 20) injected daily with 5 mg of pST (Reporcin®) from days 90 to 109 of gestation. Gilts were slaughtered on day 110 to collect mammary glands and blood samples were obtained on days 89, 96, 103 and 109 of gestation. Treated gilts gained more BW (P &lt; 0.05) and lost more backfat (P &lt; 0.05) than CTL gilts during treatment. There was a treatment x day effect (P &lt; 0.01) on IGF-1, glucose and urea concentrations in blood. Concentrations of IGF-1 increased fourfold (P &lt; 0.01) in pST compared with CTL gilts on days 96, 103 and 109 of gestation. Insulin values were also greater on days 96 (P &lt; 0.01) and 103 (P = 0.01), and tended to be greater (P &lt; 0.10) on day 109 of gestation in pST gilts. Glucose was greater in pST than CTL gilts on days 96 (P &lt; 0.01), 103 (P &lt; 0.01) and 109 (P = 0.01). Injections of pST did not affect weight of mammary extraparenchyma (P &gt; 0.10) but increased mammary parenchymal mass (1922.2 vs 1576.1 ± 123.9 g, P &lt; 0.05). Mammary parenchyma contained more (P &lt; 0.05) protein, DNA and RNA and less fat (P &lt; 0.05) and dry matter (P &lt; 0.01) in pST than CTL gilts. These findings demonstrate that increasing circulating IGF-1 in late-pregnant gilts can stimulate mammary development both in terms of total parenchymal mass and of parenchymal tissue composition.

Exogenous porcine somatotropin stimulates mammary development in late-pregnant gilts

The goal of this project was to determine if increasing insulin-like growth factor-1 (IGF-1) concentrations in late pregnancy can stimulate mammogenesis in gilts. Yorkshire × Landrace gilts of a similar body weight (BW; 196.2 ± 6.2 kg) on day 89 of gestation were separated in 2 groups, namely, controls (CTL, n = 17) that were injected with sterile water, and porcine somatotropin-treated (pST, n = 20) that received injections of 5 mg of pST (Reporcin). Injections were given daily from days 90 to 109 of gestation and gilts were slaughtered on day 110 to collect mammary glands for compositional analyses. Blood samples were obtained on days 89, 96, 103, and 109 of gestation to measure IGF-1, free fatty acids (FFA), urea, glucose, and insulin concentrations. Treated gilts gained more BW (22.7 vs. 18.2 kg, P < 0.05) and lost more backfat (P < 0.05) than CTL gilts during the treatment period. There was a treatment × day effect (P < 0.01) on IGF-1, glucose, and urea concentrations. Concentrations of IGF-1 increased 4-fold (P < 0.01) in pST compared with CTL gilts on days 96, 103, and 109 of gestation. Insulin values were also greater on days 96 (P < 0.01) and 103 (P = 0.01), and tended to be greater (P < 0.10) on day 109 of gestation in pST gilts. Glucose was greater in pST than CTL gilts on days 96 (P < 0.01), 103 (P < 0.01), and 109 (P = 0.01). Concentrations of urea were lower (P < 0.01) on days 96, 103, and 109 of gestation in gilts receiving pST injections, and FFA was not altered by treatment on any sampling day (P > 0.10). Injections of pST did not affect mammary extraparenchymal tissue weight (P > 0.10) but increased mammary parenchymal mass (1922 vs. 1576 ± 124 g, P < 0.05). The composition of parenchymal tissue was also altered by treatment. Mammary parenchyma from pST gilts contained more (P < 0.05) protein, DNA and RNA and less fat (P < 0.05) and dry matter (P < 0.01) than that from CTL gilts. These findings provide a clear demonstration that increasing circulating IGF-1 in late-pregnant gilts can stimulate mammary development both in terms of total parenchymal mass and of parenchymal tissue composition.

Body condition of late pregnant gilts affects the expression of selected adipokines and their receptors in mammary fat and backfat tissues

The impact of body condition in late gestating gilts on gene expression of selected adipokines and their receptors in backfat and mammary fat tissues was studied. The presence of associations between mammary gland composition variables and the mRNA abundance of selected genes and serum concentrations of adiponectin and leptin was also investigated. A total of 45 gilts were selected at mating based on their backfat depth and were allocated to three groups: (1) low backfat (LBF; 12-15 mm; n = 14), (2) medium backfat (MBF; 17-19 mm; n = 15), and (3) high backfat (HBF; 22-26 mm; n = 16). Gilts were fed different amounts of a conventional diet to maintain differences in backfat depth throughout the gestation period. Blood samples were collected at day 109 of gestation to measure adiponectin and leptin serum concentrations. Gilts were slaughtered on day 110 of gestation, and mammary glands were collected to determine mammary composition. Mammary fat and backfat tissues were also sampled to measure the mRNA abundance of selected genes. In mammary fat tissue, there was an effect of body condition on the prolactin (PRL; P = 0.01), adiponutrin (PNPLA3; P < 0.10), and prolactin receptor long form (PRLR-LF; P < 0.10) genes. There was a greater PRL mRNA abundance in mammary fat tissue from HBF than LBF or MBF gilts (P < 0.05). The PNPLA3 mRNA abundance was lower in HBF than in MBF gilts (P < 0.05), and that of PRLR-LF was lower in LBF than in HBF gilts (P < 0.05). In backfat, body condition affected the mRNA abundance of leptin (P < 0.05) and PNPLA3 (P < 0.01), with the greatest expression levels being observed in HBF gilts for both genes. Association analyses suggest a detrimental effect of high circulating leptin concentrations on gilts mammary development, as reflected by the negative correlations between serum leptin and protein percent (r = -0.66, P < 0.01), and concentrations of DNA (r = -0.62, P < 0.01) and RNA (r = -0.60, P < 0.01) in mammary parenchyma. Current results show that body condition of gilts at the end of gestation can affect the expression of adipokines in mammary fat and backfat tissues, with a different regulation of transcript abundance being observed in these two fat depots. Results also suggest that circulating leptin is strongly associated with mammary gland composition of late pregnant gilts, whereas locally synthesized leptin from mammary fat tissue is not.

Using domperidone to induce and sustain hyperprolactinemia in late-pregnant gilts

Prolactin controls mammary development as well as the lactogenic and galactopoietic processes in sows and increasing prolactin during gestation can augment milk yield. The dopamine receptor antagonist domperidone can increase circulating prolactin concentrations in pigs, but the ideal dose to achieve sustained hyperprolactinemia remains unknown. An experiment was performed to develop a protocol for using domperidone in studies of rapid and sustained hyperprolactinemia in late-pregnant gilts. On day 90 of gestation, gilts were divided into 4 groups: (1) intramuscular (IM) injections of canola oil (3 mL, controls [CTL], n = 9), (2) IM injections with 0.1 mg/kg BW of domperidone (low [LO], n = 8), (3) IM injections with 0.5 mg/kg BW of domperidone (medium [ME], n = 11), and (4) IM injections with 1.0 mg/kg BW of domperidone (high [HI], n = 11). Injections were given daily at 8:05 from days 90 to 109 of gestation. Treated gilts also received domperidone per os (0.5 mg/kg BW) at 8:00 and 20:00 on days 89, 90, and 91 of gestation. Three jugular blood samples were collected from all gilts at 6-h intervals on days 89, 90, and 91 of gestation, then twice daily on days 92, 93, and 94. Thereafter, samples were obtained at 8:00 every other day until day 114 of gestation. Blood was sampled serially from 9 CTL and 11 HI gilts on days 89 and 94 of gestation. On day 89 of gestation, prolactin concentrations for LO, ME, and HI gilts increased within 6 h of domperidone per os (P < 0.001). From days 89 until 93 of gestation, the area under the curve (AUC) for LO, ME, and HI gilts was greater than that for CTL gilts (P < 0.001), whereas from days 89 until 114, ME and HI gilts had greater AUC than CTL and LO gilts (P < 0.05). Results demonstrate that the combination of per os treatment with IM injections of 0.5 mg/kg of domperidone in an oil emulsion leads to the rapid and sustained release of prolactin over 24 d in late-pregnant gilts. Higher doses of domperidone failed to further increase circulating prolactin levels. These findings provide a useful strategy to induce sustained hyperprolactinemia in late-pregnant gilts.

Uptake and virological outcomes of single- versus multi-tablet antiretroviral regimens among treatment-naïve youth in the HIV Research Network

OBJECTIVES

Several single-tablet regimens (STRs) are now available and are recommended for first-line antiretroviral therapy (ART); however, STR use for youth with HIV (YHIV) has not been systematically studied. We examined the characteristics associated with initiation of STRs versus multi-tablet regimens (MTRs) and the virological outcomes for youth with nonperinatally acquired HIV (nPHIV).

METHODS

A retrospective cohort study of nPHIV youth aged 13-24 years initiating ART between 2006 and 2014 at 18 US HIV clinical sites in the HIV Research Network was performed. The outcomes measured were initiation of STRs versus MTRs, virological suppression (VS) at 12 months, and time to VS. Demographic and clinical factors associated with initiation of STR versus MTR ART and VS (< 400 HIV-1 RNA copies/mL) at 12 months after initiation were assessed using multivariable logistic regression. Cox proportional hazards regression was used to assess VS within the first year.

RESULTS

Of 987 youth, 67% initiated STRs. Of the 589 who had viral load data at 1 year, 84% of those on STRs versus 67% of those on MTRs achieved VS (P < 0.01). VS was associated with STR use [adjusted odds ratio (AOR) 1.61; 95% confidence interval (CI) 1.01-2.58], white (AOR 2.41; 95% CI 1.13-5.13) or Hispanic (AOR 2.38; 95% CI 1.32-4.27) race/ethnicity, and baseline CD4 count 351-500 cells/μL (AOR 1.94; 95% CI 1.18-3.19) and > 500 cells/μL (AOR 1.76; 95% CI 1.0-3.10). STR use was not associated with a shorter time to VS compared with MTR use [hazard ratio (HR) 1.07; 95% CI 0.90-1.28].

CONCLUSIONS

Use of STR was associated with a greater likelihood of sustained VS 12 months after ART initiation in YHIV.

Nutritional impact on mammary development in pigs: a review

Milk yield is a crucial component of a sow operation because it is a limiting factor for piglet growth rate. Stimulating mammary development is one avenue that could be used to improve sow milk production. A number of studies have shown that nutrition of gilts or sows during the periods of rapid mammary accretion occurring during prepuberty, gestation, and lactation can affect mammary development. The present review provides an overview of all the information currently published on the subject. Various nutritional treatments can bring about increases in mammary tissue weight ranging from 27% to 52%. It was clearly established that feed restriction from 90 d of age (but not before 90 d) until puberty has detrimental effects on mammary development in pigs. Ad libitum feeding during that period increased mammary parenchymal weight by 36% to 52%. Body condition is also important because gilts that were obese (36-mm backfat) or too lean (12- to 15-mm backfat) in late gestation had less developed mammary tissue. Furthermore, overfeeding energy in late gestation seems to be detrimental. On the other hand, increasing energy and protein intakes of sows during lactation was beneficial for development of mammary tissue. Feeding certain plant extracts with estrogenic or hyperprolactinemic properties may also prove beneficial in stimulating mammary development at specific physiological periods. For example, feeding genistein to prepubertal gilts increased parenchymal DNA by 44%. Even though research was carried out on the nutritional control of mammogenesis in pigs, it is evident that much remains to be learned before the best nutritional strategy to enhance mammary development can be developed.

TRIENNIAL LACTATION SYMPOSIUM/BOLFA: Adipokines affect mammary growth and function in farm animals

The essential role of mammary fat pads in mammary growth and morphogenesis was the first indication that biologically active molecules, secreted from adipocytes or other stromal cells, could regulate endocrine cues for growth and function of the mammary gland. The presence of leptin and adiponectin receptors in mammary tissues suggested that locally produced or circulating adipokines could affect mammary growth and function. Herein, we present the current knowledge on the role of adipokines in mammary cell proliferation and differentiation and in lactogenesis and galactopoiesis in farm animals. We also address the role of milk adipokines in the neonate. Accumulating evidence suggests that adipokines could act as metabolic sensors, regulating mammary growth and function in periods of metabolic adaptations such as late pregnancy and early lactation. Indeed, different experiments reported that adiponectin and leptin expression varies according to physiological stages and nutritional status of the animal. The current review also demonstrates that adipokines, such as leptin and adiponectin, are important regulators of the action of lactogenic hormones in the mammary gland. Findings also suggest important roles for adipokines in growth and intestinal maturation of the neonate.

Impact of diet deprivation and subsequent overallowance during gestation on lactation performance of primiparous sows

The impact of diet deprivation followed by overallowance during gestation on metabolic status of pregnant gilts and their lactation performance was determined. Gilts were fed a standard diet until day 27 of gestation and were subsequently reared under a control (CTL; n = 28) or an experimental (treatment, TRT; n = 26) dietary regimen. The experimental regimen provided 70% (restriction diet, RES) and 115% (overallowance diet, OVER) of the protein and NE contents provided by the CTL diet. The RES diet was given from days 28 to 74 of gestation followed by the OVER diet from day 75 until farrowing. Blood samples were obtained from all gilts on days 28, 75, and 110 of gestation, and on days 3 and 20 of lactation to measure concentrations of IGF-1, urea, FFA, and glucose. Milk samples were collected from 12 sows per treatment on day 19 of lactation and sow feed intake was recorded daily throughout lactation. Piglets were weighed at 24 h (after standardization of litter size), and on days 7, 14, and 21 (weaning). The TRT gilts gained less BW than CTL gilts (17.3 vs. 31.7 kg; P < 0.01) from days 28 to 75 of gestation and more BW (29.5 vs. 21.9 kg; P < 0.01) from days 75 to 110, but their overall gain from mating to day 110 was lower (61.4 vs. 67.2 kg; P < 0.05). Metabolic status during gestation was affected, with TRT gilts having less IGF-1 and urea, and more FFA than CTL gilts on day 75 (P < 0.01), and more urea on day 110 (P < 0.01). Growth rate of suckling piglets, sow lactation feed intake, and standard milk composition in late lactation (DM, fat, protein, lactose) were not affected by treatment (P > 0.10). In conclusion, diet deprivation of gilts as of day 28 of gestation followed by overfeeding from day 75 of gestation until farrowing did not improve lactation performance. It is likely that the compensatory growth that took place in late gestation was not adequate to illicit beneficial effects.

Comparison of major bleeding risk in patients with non-valvular atrial fibrillation receiving direct oral anticoagulants in the real-world setting: a network meta-analysis

OBJECTIVE

To conduct a systematic literature review (SLR) and network meta-analysis (NMA) of real-world studies comparing major bleeding risk among patients with non-valvular atrial fibrillation (NVAF) on direct oral anticoagulants (DOACs) or warfarin.

METHODS

Systematic searches were conducted in MEDLINE and Embase for full-text articles published between January 1, 2003 and March 18, 2017. Eligible studies compared at least two of the following in a real-world setting: warfarin, apixaban, dabigatran, rivaroxaban, or edoxaban. A Bayesian NMA was conducted to estimate hazard ratios (HRs) for major bleeding using a random-effects model.

RESULTS

Eleven studies were included in the NMA. Nine studies included DOACs vs Warfarin comparisons, and four studies included DOACs vs DOACs comparisons (two studies included both comparisons). Median follow-up duration ranged from 2.6-31.2 months. No evidence was identified for edoxaban. Apixaban was associated with a significantly lower risk of major bleeding compared to other oral anticoagulants (warfarin HR = 0.58; 95% credible interval [CrI] = 0.48-0.69; dabigatran = 0.73; 0.61-0.87; rivaroxaban = 0.55; 0.46-0.66). Dabigatran was associated with a significantly lower risk than warfarin (0.79; 0.71-0.88) and rivaroxaban (0.76; 0.67-0.85), and rivaroxaban was not statistically different from warfarin (1.05; 0.91-1.19). Sensitivity analyses with standard dose and sponsorship showed consistent results.

CONCLUSION

DOACs were associated with lower or similar risk of major bleeding compared with warfarin in NVAF patients. Apixaban was associated with a significantly lower risk of major bleeding than other DOACs. Dabigatran was associated with a significantly lower risk of major bleeding compared to rivaroxaban and warfarin.

Oxytocin injections in the postpartal period affect mammary tight junctions in sows

The potential impacts of injecting oxytocin (OXY) to sows in the early postpartum period on the quality of mammary tight junctions, milk composition, and immune status of sows and piglets were studied. Postparturient sows received i.m. injections of either saline (control [CTL]; = 10) or 75 IU of OXY ( = 10). Injections were given twice daily (0800 and 1630 h) starting on d 2 of lactation (i.e., between 12 and 20 h after birth of the last piglet), totaling 4 injections. Milk samples were obtained before the first injection (d 2 morning [AM]), before the second injection (d 2 afternoon [PM]), and on d 4 PM and d 5 PM. Blood samples were obtained from sows before milking on d 2 AM, d 2 PM, and d 5 PM. On d 5 of lactation, a blood sample was obtained from 3 piglets per litter. Circulating concentrations of prolactin, IGF-I, lactose, and IgA in sows did not differ between treatments at any time ( > 0.10), but OXY sows had less IgG than CTL sows ( < 0.01) on d 2 PM before the second OXY injection. There were differences in milk composition on d 2 PM, with OXY sows having more IGF-I ( < 0.01), solids ( < 0.05), protein ( < 0.01), energy ( < 0.05), and IgA ( < 0.01) and a greater Na:K ratio ( < 0.01) than CTL sows. These differences were not seen in the next 2 milk samples, except for protein and IgA that still tended ( < 0.10) to be greater in OXY vs. CTL sows on d 4 PM (for protein) and on d 5 PM (for IgA) after the last injection. Milk lactose content was lower in OXY vs. CTL sows on d 5 PM ( < 0.01). Values for immunoglobulin immunocrit, IgG, IgA, and IGF-I in piglet blood did not differ between treatments ( > 0.10). Injecting OXY to sows in the early postpartum period increased leakiness of the mammary tight junctions, improved composition of early milk, and may potentially affect immune status of neonatal piglets.

In vivo measures of mammary development in gestating gilts

Potential links between measures of udder morphology obtained in live pregnant gilts and mammary gland development and composition measured in mammary tissue collected at slaughter were studied. Thirty-three gilts were used. In vivo measures of gland morphology using a tape or ultrasound imaging (parenchymal area measured by ultrasound [AREA]) were obtained on d 108 ± 1 of gestation. Gilts were then slaughtered on d 110 ± 1 of gestation to collect mammary glands for dissection and compositional analyses. The various tape measures were the distance between each teat on one side of the udder (DIST-TEAT), the distance between each teat pair (DIST-PAIR), the length of the udder (sum of all DIST-TEAT), the distance between the base of the teat and the ventral midline section of the udder (MID), and the distance between the base of the teat and the exterior junction of the udder with the abdomen (EXT). The variables MID, DIST-TEAT, DIST-PAIR, and length had very poor correlations with parenchymal weight, extraparenchymal weight, or any of the measured compositional variables. On the other hand, both AREA and EXT were correlated ( < 0.01) with the weight of parenchymal tissue, total parenchymal protein, total DNA, and total RNA. The ultrasound measure AREA and the tape measure EXT were also correlated with each other ( < 0.05). These measures could, therefore, be helpful to estimate mammary development in studies where animals cannot be slaughtered. The tape measure EXT seemed to better reflect the volume of the gland than MID, and it provided as reliable an estimate of parenchymal weight as the measure of parenchymal area using ultrasound while being much easier and cheaper to obtain.

Risk of major bleeding in patients with non-valvular atrial fibrillation treated with oral anticoagulants: a systematic review of real-world observational studies

OBJECTIVE

To conduct a systematic review of real-world (RWD) studies comparing the risk of major bleeding (MB) among patients with non-valvular atrial fibrillation (NVAF) on direct oral anticoagulants (DOACs) or warfarin.

METHODS

MEDLINE, Embase, NHS-EED, and EconLit were searched for RWD studies published between January 2003 and November 2016 comparing MB risk among DOACs and warfarin. Proceedings of clinical conferences from 2012 to 2016 were reviewed.

RESULTS

A total of 4218 citations were identified, 26 of which met eligibility criteria. Most studies were retrospective analyses of administrative claims databases and patient registries (n = 23 of 26); about half were based in the United States (n = 15). Apixaban showed a significantly lower risk of MB versus warfarin in all eight included studies. MB risk was either significantly lower (n = 9 of 16) or not significantly different (n = 7 of 16) between dabigatran and warfarin; there was no significant difference between rivaroxaban and warfarin in all seven included studies. The risk was significantly lower with apixaban versus rivaroxaban (n = 7 of 7) but not significantly different from dabigatran (n = 6 of 7). MB risk was significantly lower (n = 3 of 4) or not significantly different (n = 1 of 4) with dabigatran versus rivaroxaban. No evidence was identified for edoxaban.

CONCLUSION

DOACs were associated with similar or lower risks of MB versus warfarin. A lower MB risk was consistently observed for apixaban, but less consistently for dabigatran; MB risk was similar between rivaroxaban and warfarin. Among DOACs, the risk of MB with apixaban was consistently lower than with rivaroxaban, but similar to dabigatran.

Does duration of teat use in first parity affect milk yield and mammary gene expression in second parity?

It was recently shown that a teat that is not used in the first lactation will have a reduced development and milk yield in the second lactation. In the current study, the impact of imposing a suckling period of 2, 7, or 21 d during the first lactation on piglet performance, milk composition, endocrine status, and mammary gene expression of sows in their second lactation was studied. Pregnant Yorkshire gilts were divided into 3 groups according to lactation length: 1) 2-d lactation (2D; = 20), 2) 7-d lactation (7D; = 20), and 3) 21-d lactation (21D; = 21). After weaning, sows were bred and kept for a second parity. In both lactations, litters were standardized to 12 piglets with 12 functional teats and surplus teats were sealed. In the second lactation, piglets were weighed on d 2, 7, 14, 21 (weaning), 31, and 56 postpartum, and sow feed intake was recorded. On d 110 of gestation and on d 21 of lactation, mammary biopsies were performed on 10 sows per treatment to obtain parenchymal tissue samples for determination of mRNA abundance for , , , , , and genes. Milk samples and jugular blood samples were also obtained from sows on d 21 of lactation. Standard composition analyses (DM, fat, protein, and lactose) were done in milk. Concentrations of prolactin, IGF-1, glucose, and urea were measured in blood. There was a tendency for 21D sows to consume more feed than 2D or 7D sows during the first week of lactation ( < 0.10). There was no treatment effect on BW of piglets at any time until d 56 ( > 0.10). Concentrations of prolactin, IGF-1, urea, and glucose in sows on d 21 of lactation were not affected by treatment ( > 0.10). Dry matter, fat, protein, and lactose contents in milk were not altered by treatment ( > 0.10). On d 110 of gestation, gene expression was greater ( = 0.05) in 21D sows than in 7D sows. On d 21 of lactation, gene expression of was greater ( = 0.05) and that of tended to be lower ( < 0.10) in 7D sows than in 2D sows. The mRNA abundance of also tended to be lower ( < 0.10) in 2D sows than in 7D sows. Results indicate that increasing the duration of lactation from 2 d to 7 d or to 21 d in first-parity sows did not improve growth rate of their piglets in the subsequent lactation. This suggests that suckling of a teat for 2 d during the first lactation is sufficient to ensure optimal mammary development.

Comparative study on the relations between backfat thickness in late-pregnant gilts, mammary development and piglet growth

The potential relation between body condition of gilts in late-pregnancy and litter BW gain as well as mammary development was studied using 2 sets of data. Gilts either from a commercial herd (Part 1, n = 182) or from a series of trials looking at mammary development (Part 2, n = 172) were separated in 3 groups according to backfat thickness (BF) on d 110 of gestation. Group categorization was similar for Parts 1 and 2 of the study and was: low (LOW), 13.6 ± 1.6 mm (mean ± SD); medium (MED), 17.6 ± 1.0 mm (mean ± SD); and high BF (HIGH), 21.8 ± 1.8 mm (mean ± SD) for Part 1, and LOW, 14.2 ± 1.3 mm (mean ± SD); MED, 18.1 ± 1.0 mm (mean ± SD), and HIGH 23.4 ± 2.6 mm (mean ± SD) for Part 2. The effects of BF group on piglet BW gain (Part 1) or on various mammary gland characteristics (Part 2) were determined using ANOVA. Litters from HIGH sows tended to have a greater lactation BW gain than those from LOW sows (P < 0.10). Sows with HIGH BF had more mammary parenchymal tissue and more total protein and total DNA than MED and LOW sows (P < 0.05), which led to greater total protein and total DNA contents (P < 0.05). There were strong positive correlations (P < 0.0001) between parenchymal weight and total protein, total DNA, and total RNA. Results suggest that it is beneficial for primiparous sows to have greater BF (i.e., 20 to 26 mm) at the end of gestation to achieve optimal mammary development and greater litter BW gain in the subsequent lactation.