Maternal Dietary Nitrate Supplementation Lowers Incidence of Stillbirth in Hyper Prolific Sows under Commercial Circumstances

The objective of the current experiment was to investigate whether or not maternal dietary nitrate supplementation, a nitric oxide (NO) precursor, could reduce piglet losses under commercial circumstances. In the current experiment, 120 hyper prolific gilts and sows (Landrace x Yorkshire: Danbred) on a commercial farm in Denmark received either a control lactation diet or a lactation diet containing 0.1% of calcium nitrate (containing 63.1% of nitrate) from approximately 5 days pre-farrowing until day 4 of lactation. The number of piglets born total, alive, and stillborn, as well as birth weights, weights after cross-fostering (approximately 1 day of age), 24 h after cross-fostering, day 3 of age, and at weaning was recorded. Placentas of sows were collected after expulsion and scored on redness. No effect of nitrate supplementation was found on piglet weight, piglet growth, placental redness score, and pre-weaning mortality during lactation. Maternal dietary nitrate supplementation decreased stillbirth percentage with 2.5% (9.9 vs. 7.4%; p = 0.05). It can be concluded that maternal dietary nitrate supplementation shows the potential to decrease the incidence of stillbirth in hyper prolific sows.

Organic Acids Improve Growth Performance with Potential Regulation of Redox Homeostasis, Immunity, and Microflora in Intestines of Weaned Piglets

The objective of this study is to evaluate the effects of organic acids on piglet growth performance and health status. A total of 360 weanling pigs (5.3 ± 0.6 kg) were randomly allotted to 3 treatment groups with 12 replicates of 10 pigs/pen. Piglets were fed the same basal diet and given either water (control) or water plus 2.0 L/Ton organic acid (OA) blends, such as OA1 or OA2, respectively, for 7 weeks. Compared to the control, OA1 and OA2 improved growth performance and/or reduced the piglets’ diarrhea rate during the various periods and improved small intestinal morphology at days 14 and/or 49. OA1 and OA2 also increased serum CAT and SOD activities and/or T-AOC and, as expected, decreased MDA concentration. Moreover, at day 14 and/or day 49, OA1 and OA2 increased the jejunal mRNA levels of host defense peptides (PBD1, PBD2, NPG1, and NPG3) and tight junction genes (claudin-1) and decreased that of cytokines (IL-1β and IL-2). Additionally, the two acidifiers regulated the abundance of several cecum bacterial genera, including Blautia, Bulleidia, Coprococcus, Dorea, Eubacterium, Subdoligranulum, and YRC2. In conclusion, both of the organic acid blends improved piglet growth performance and health status, potentially by regulating intestinal redox homeostasis, immunity, and microflora.

Composition of the Fecal Microbiota of Piglets at Various Growth Stages

Gastrointestinal (GI) microbiota play an important role in promoting growth in piglets. However, studies on microbiota composition at various growth stages are lacking. We measured body weights of Jinfen White and Mashen piglets every 7 days and collected their fecal samples by rectal swabbing at nine time points during suckling (1–28 days) and nursery (35–70 days) stages to gain insight into microbiota variability during piglet growth. The fecal microbiota were characterized via 16S rRNA gene sequencing to analyze the effects of microbial diversity on piglet growth and development preliminarily. The results showed that although the two breeds of piglets have similar body weights at birth, weaned Jinfen White piglets demonstrated a significantly greater body weight and daily weight gain than weaned Mashen piglets (P < 0.01). A total of 1,976 operational taxonomic units (OTUs) belonging to 27 phyla and 489 genera were uncovered, in which the highest numbers of OTUs belong to the phyla Firmicutes and Bacteroidetes. Lactobacillus, Bacteroides, and Prevotellaceae NK3B31 groups accounting for 12.4, 8.8, and 5.8% of OTUs, respectively, showed relatively high abundance at the genus level. Nine sampling time points were divided into three growth stages, namely, immediate postfarrowing (1 day old), suckling (7, 14, and 21 days old), and nursery (28, 35, 49, 63, and 70 days old), on the basis of the results of microbial diversity, principal coordinate, and co-occurrence network analyses. In addition, it identified 54 discriminative features in the microbiota between two breeds of piglets by LEfSe analysis, in which 17 genera enriched the microbiota community of Jinfen White piglets. Finally, abundances of 29 genera showed significant positive correlations with body weights and daily weight gain of piglets. Conversely, abundances of 12 genera demonstrated significant negative correlations with body weights of piglets. The results of our study will provide a theoretical basis for succession patterns in fecal microbiota of piglets and suggest the need for meticulous management of piglets in pig production.

Positive Human Contact and Housing Systems Impact the Responses of Piglets to Various Stressors

This experiment studied the effects of lactation housing systems and human interaction on piglets’ responses to routine stressors. Forty litters of piglets were reared in either a standard farrowing crate (FC) or a loose farrowing and lactation pen (LP; PigSAFE pen) and received either routine contact with humans (C) or regular opportunities for positive human contact (+HC; 3 min of patting, stroking and scratching 5 times/week). Behavioural and physiological responses to routine husbandry procedures, weaning, novelty and humans were studied in addition to effects on piglet growth, injuries and survival. Compared to C piglets, +HC piglets vocalised for shorter durations (p = 0.018) during husbandry procedures and showed a lower intensity of escape behaviour during iron injection (p = 0.042) and oral vaccination (p = 0.026) at 3 d of age, capture at 2 wk of age (p < 0.001), and intramuscular vaccination (p = 0.005) at 3 wk of age. +HC piglets at 2 wk of age were faster than C piglets to approach (p = 0.048) and interact (p = 0.042) with a stationary unfamiliar human. Compared to LP piglets, FC piglets showed a lower intensity of escape behaviour during capture and iron administration by a stockperson at 3 d of age (p = 0.043). FC piglets at 2 wk of age were faster than LP piglets to approach (p = 0.005) and interact (p = 0.027) with a novel object and approach (p = 0.009) and interact (p = 0.008) with an unfamiliar human. FC piglets had fewer injuries than LP piglets at 2 wk of age (p = 0.004). +HC pigs had fewer injuries than C pigs after weaning (p = 0.003). After weaning there were more pigs from LP than FC observed to be upright (both stationary, p = 0.002 and walking, p = 0.024), vocalizing (p = 0.004), nosing another pig (p = 0.035) and nosing the pen floor (p = 0.038). There were no significant effects on neutrophil:lymphocyte ratios or plasma cortisol concentrations 1.5 h after weaning. However, 25 h after weaning +HC pigs had higher haptoglobin concentrations than C pigs (p = 0.002), and C/LP pigs had higher cortisol concentrations than +HC/LP and C/FC pigs (p = 0.012). There were no significant effects on piglet growth, the number of piglets born alive or the number stillborn, however there were more piglets weaned from FC than LP (p = 0.035). The results from this experiment raise questions that require further research on the ability of pigs reared in loose pens to cope with stressors such as exposure to humans, novelty, husbandry procedures and weaning. This experiment also provides evidence that regular positive human interaction reduces pigs’ fear of humans and husbandry procedures imposed by stockpeople. More research is required to determine if any of these effects are sustained long-term.

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.

PSII-26 Early- and mid- lactation milk traits are associated with piglet growth during lactation

Preweaning piglet growth is tied to milk quality and consumption. To determine the relationship of milk components from parity 1–4 dams and piglet growth, early and mid-lactation (d 2 and 16) milk samples were collected from 48 litters and analyzed for protein, fat, somatic cell count, lactose, solids, total solids, and milk urea nitrogen. Each milk trait was categorically identified at 25, 50 or 75 percentiles as low, moderate, or high, respectively. Mixed models (SAS); dam repeated, sire random, and adjusted for parity and litter size; were used to determine association of individual milk traits with piglet lactation growth (gain calculated from body weights at birth, d10, and weaning; WN). Moderate levels of d2 milk protein were associated with the greatest gain during lactation in comparison to low and high levels (Table 1). High levels of d2 milk lactose and d2 solids were both related to piglet gain over the lactation period (Table 1). Evaluation of d16 milk traits with piglet gain over lactation indicated high levels of d16 fat, d16 solids, and d16 total solids had the greatest gain in comparison to moderate and low levels of each trait (Table 1). Within phase of lactation weight gain, association of d2 or d16 milk traits with early weight gain (birth to d10) or late weight gain (d10 to WN) were performed. The greatest early lactation gains (birth to d10) were associated with moderate levels of d2 protein, high levels of d2 lactose and d2 solids, and low levels of d2 MUN (Table 2). High levels of milk fat, lactose, and solids at d2 were associated with piglet gain during late lactation (d10 to WN; Table 3). In general, greater levels of lactose in d2 milk and fat in d16 milk were associated with piglet gain during lactation.

PSVI-10 Mint oil, yeast cell, and ɣ-tocopherol supplementation in gestation and lactation diets on the antioxidant status of the sow and offspring performance during the suckling period

Times of high metabolic activity can lead to increased incidence of oxidative stress in gestating and lactating sows which may impact suckling piglet performance. Identifying products that could help alleviate this stress would be beneficial. A study assessed yeast cell, mint oil, and ɣ-tocopherol supplementation in gestation and lactation diets on sow antioxidant status and offspring performance to weaning. A total of 53 sows and gilts (206.2 ± 35.3 kg at breeding) were assigned to one of 4 diet regimens: Control (CON), control + yeast cell at 0.15% (YC), control + mint oil at 10 ppm (MO), and control + ɣ-tocopherol at 200 ppm (GT). Diets were provided from breeding through weaning (lactation day 21 ± 2). Control diets were formulated to meet nutrient requirements in gestation (3279 kcal ME/kg, 0.63% SID Lys) and lactation (3279 kcal ME/kg, 1.06% SID Lys). Yeast cell, mint oil and ɣ-tocopherol were added as a top dress once daily. Sow variables evaluated were weight at beginning and end of each period, feed intake, litter characteristics at birth, and antioxidant status in serum, colostrum and milk. Piglet growth during suckling was determined. Data were analyzed as randomized complete block and Tukey’s adjustment as means separation test. Maternal diet had minimal impact on gestation or lactation feed intake or sow body weight. There was no effect on litter size or piglet birth weight. Piglets from GT-fed sows tended to be heavier at weaning than YC piglets due to differences in daily gain. Glutathione content in colostrum and d14 milk samples did not differ by maternal treatment. D14 milk Glutathione content was 40%, 59%, 62%, and 51% greater in CON, YC, MO, and GT sows, respectively, compared to colostrum. No difference in superoxide dismutase content in serum and d14 milk observed. Inclusion of ɣ-tocopherol in sow gestation and lactation diets enhanced suckling piglet growth; connection to sow antioxidant status remains unclear.