Landrace Gilts Research Articles

Effect of Body Weight and Age at Puberty and Mating on Subsequent Gilt Development Weights, Litter Traits, and Colostral Immunoglobulin G of the F1 Large White X Landrace Gilts

Effect of Body Weight and Age at Puberty and Mating on Subsequent Gilt Development Weights, Litter Traits, and Colostral Immunoglobulin G of the F1 Large White X Landrace Gilts

Experimenting with Pig-based Skin Model for Burns. Testing of Mean Literature Findings.

Introduction: Animal models that closely mimic human burn wound healing processes are essential for developing effective burn wound treatments. Pigs are useful animal models for studying burn wound healing. From their extensive literature review, Andrews and Cuttle (2017) reported mean temperature and exposure time values. This study was done to provide initial burn depth for another experiment comparing two burn wound treatments. The secondary goal was to validate a systematic review on porcine burn model standardization. Material and Methods: Six four-week-old Large White x Landrace gilts were housed in a closed structure for 10 days to acclimatize. The procedures were performed under general anesthesia. A round 2.5 cm copper plate welded to an aluminum rod with a wooden handle caused the injuries. The burning device was used to reach a contact temperature of 110 C on the pig's skin. The objective was to create a superficial partial thickness (SPT) burn for 10 seconds (Group 10s) and a deep partial thickness (DPT) burn for 20 seconds (Group 20s) using a plate heated at 110ºC. No stabilizer or pressure controller was used. Wounds were conclusively dressed and harvested 24 hours later. The usual hematoxylin-eosin protocol was used to cut and stain 4-micron sections. Results: A significant difference (p 0.01) was observed in dermis involvement, with a mean of 85.61 % (95% CI= 80.62 to 90.61) for group 10s and 123.71% (95% CI= 114.91 to 132.50) for group 20s. An exposure time of 20 seconds increased dermis depth-related total collagen denaturation by almost 50% compared to 10 seconds. Conclusions: In conclusion, our experiment produced DPT burns in 10 seconds and FT burns in 20 seconds without a pressure application device.

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 ± 127.1g; P < 0.001) and total extraparenchymal tissue (1,691.0 vs. 2,407.0 ± 125.3g; 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 ± 2.7kg 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 ± 0.53mg/g DM) and RNA (7.76 vs. 12.33 ± 0.70mg/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 ± 2.8ng/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.

195 The Impact of Developmental Housing Type on Toe Growth and Wear in Sows

Abstract Swine housing systems are ever-changing to improve animal husbandry. Recently, gilts are being transitioned from gestation stalls to pens with resulting phenotypic effects being unclear. Toe growth and wear are often negated during structural analysis, with objective data of their trends being limited. Therefore, the objective of this study was to determine the impact of housing type on toe growth and wear during gestation of golts. York x Landrace gilts (n = 321) were used at the UNL ENREC swine farm. Gilts were randomly assigned to either pen (4 pigs/pen; 2.09 m2/pig) or stall (2.06 x 0.48 m) housing at 210 days of age. For analysis, gilts were lifted in a Feet First Chute (Zinpro) to permanently mark the lateral toes on the left front and back feet at ~1 cm from the coronary band. Toe length above and below the mark was measured with a digital caliper. Measurements took place before breeding (PRE), at day 30 (D30), day 57 (D57), and day 100 (D100) of gestation, and at weaning (WEAN). Estimated marginal means were calculated with regards for development group, housing type, and initial toe lengths. From PRE to D100, stall housed gilts had greater (P &amp;lt; 0.01) front growth (32.5 vs. 26.8 mm), similar front wear (-25.3 vs. -23.4 mm), greater (P &amp;lt; 0.01) back growth (39.1 vs. 34.3 mm), greater (P &amp;lt; 0.01) back wear (-32.3 vs. -28.1 mm), a greater (P &amp;lt; 0.01) total front length (41.6 vs. 39.6 mm), and a slightly longer total back length (45.5 vs. 45 mm). From D100 to WEAN, pen housed gilts had more (P &amp;lt; 0.05) back wear (-5.12 vs. -4.32 mm) and subsequently less (P &amp;lt; 0.01) total back growth (4.88 vs. 6.50 mm); with no other differences showing significance. These results suggest that housing can alter feet conformation with stall developed gilts having longer toes when entering farrowing.

Net Portal Appearance of Amino Acids in Iberian and Landrace Pigs Fed Different Protein Content in the Diet

Iberian pigs have low rates of muscle protein deposition compared with modern breeds. Differences in net portal appearance (NPA) of amino acids (AA) might partially explain that. NPA of AA was measured in six Iberian and six Landrace gilts (28 kg) fitted with catheters in portal and mesenteric (para-aminohippuric acid infusion) veins, and carotid artery. Blood samples from porta and artery were simultaneously taken at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, and 6-h after feeding two isoenergetic diets (14-14.5 MJ metabolizable energy/kg dry matter) with different crude protein (145 (LCP) and 187 (HCP) g/kg dry matter) content. NPA of essential AA (EAA) and non-essential AA (NEAA) was lower (p < 0.05) in Iberian than Landrace pigs, and in LCP than HCP diet. Fractional absorption (NPA/AA intake) of EAA, NEAA, and total AA was, respectively, 36, 49, and 44% lower in LCP than HCP diet in Iberian pigs; and 8, 2, and 4% greater in Landrace pigs. Fractional absorption of EAA, NEAA, and total AA was 42, 68, and 60% lower in Iberian than Landrace pigs fed LPC diet; and 1, 36, and 26% when fed the HCP diet. NPA of AA may partially explain the low growth rate of Iberian pigs.

Choline supplementation regulates gut microbiome diversity, gut epithelial activity, and the cytokine gene expression in gilts.

Choline is an essential nutrient that is necessary for both fetal development and maintenance of neural function, while its effect on female ovarian development is largely unexplored. Our previous study demonstrated that choline supplementation promotes ovarian follicular development and ovulation, although its underlying mechanism was unclear. To uncover the potential regulation pathway, eighteen female Yorkshire × Landrace gilts were fed with either standard commercial diet (Control group, n = 9) or choline supplemented diet (Choline group, additional 500 mg/kg of control diet, n = 9) from day 90 of age to day 186. At day 186, feces samples were analyzed for effects on the gut microbiome using 16S ribosomal RNA gene V3-V4 region sequencing with Illumina MiSeq, serum samples were analyzed for trimethylamine (TMA) and trimethylamine-N-oxide (TMAO) using HILIC method, and jejunum tissues were analyzed for immune related gene expression using qRT-PCR. Our results show that choline supplementation did not alter the circulating level of TMA and TMAO (P > 0.05), but rather increased gut microbiome alpha diversity (P < 0.05). Beta diversity analysis results showed that the choline diet mainly increased the abundance of Firmicutes, Proteobacteria, and Actinobacteria, but decreased the abundance of Bacteroidetes, Spirochaetes, and Euryarchaeota at the phyla level. Meta-genomic analysis revealed that choline supplementation activated pathways in the gut microbiota associated with steroid hormone biosynthesis and degradation of infertility-causing environmental pollutants (bisphenol, xylene, and dioxins). To further verify the effect of choline on intestinal activity, a porcine intestine cell line (IPEC-J2) was treated with serial concentrations of choline chloride in vitro. Our data demonstrated that choline promoted the proliferation of IPEC-J2 while inhibiting the apoptotic activity. qRT-PCR results showed that choline significantly increased the expression level of Bcl2 in both IPEC-J2 cells and jejunum tissues. The expression of IL-22, a cytokine that has been shown to impact ovarian function, was increased by choline treatment in vitro. Our findings reveal the beneficial effect of choline supplementation on enhancing the gut microbiome composition and intestinal epithelial activity, and offer insights into how these changes may have contributed to the ovarian development-promoting effect we reported in our previous study.

Potential Role of LYN, CCL2, ITGB3 and IL6 Genes in the Immune Response of Porcine Buccal Mucosa Cells

Abstract The genes considered in this study, namely, LYN, CCL2, ITGB3 and IL6 can be related to immune response in porcine buccal mucosa cells primary cultured in vitro. These genes are also responsible for, inter alia, cell migration, differentiation, proliferation and apoptosis, intracellular signal transduction, extracellular matrix binding and wound healing. A total of 20 pubertal crossbred Landrace gilts bred on commercial farms were used to obtain buccal mucosa cell cultures, which were harvested on the 7th, 15th and 30th day after initiation of the culture. Expression levels of LYN, CCL2, ITGB3 and IL6 were evaluated employing Real-Time Quantitative Polymerase Chain Reaction. All studied genes showed expression. The expression of CCL2 on day 15 was the highest of all factors measured. The greatest difference between the measurements occurred in gene IL6, between 7th and 15th day, while the least difference between the measurements occurred in gene LYN, between 7th and 15th day. Moreover, on the 7th day, LYN presented the lowest expression among all studied genes. Although in vitro conditions are much more controlled than in vivo conditions, all the factors that may positively or negatively affect cultured cells still cannot be fully predicted. Nevertheless, LYN, CCL2, ITGB3 and IL6 are a valuable starting point for studying further immunological processes in oral mucosal epithelial cells. Given their high regenerative potential, research into them is a highly valuable source of information for future wound healing therapies, where immunological processes should be carefully considered.

Body size measurement and live body weight estimation for pigs based on back surface point clouds

Body measurement is an important link in monitoring the growth of livestock in breeding management. Conventional measurements are notoriously difficult, unstable, stressful and time-consuming. 3D Computer vision technology has demonstrated its superiority in body size measurement and live body weight estimation because it has advantages of being both non-contact and effective. The objective of this paper was validating the use of single-frame surface point clouds to measure the body size, and develop a model to estimate the pig weight. With a limit bar not applied, a Kinect camera was fixed above the drinking area allowed multiple images of pigs to be captured at one time in a group-house. Body size parameters were extracted from back surface point clouds, and subsequently used as independent variables to build the three regression analysis models: i) stepwise regression analysis, ii) ridge regression analysis, and iii) partial least squares regression analysis. An experiment was conducted on fifty pigs in a group-house, half of which were Landrace gilts, half were Yorkshire shoats. The result of size measurement showed the mean relative absolute errors of body length, height, shoulder width were 0.7%, 1.8%, and 3.3%, respectively. Final ridge regression equation was developed with an R2 of 0.958 and a MAE of 2.961 kg. It was concluded that the proposed methods based on Kinect v2 was shown to be accurate and reliable for body size measurement and live body mass estimation.

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.

Confirmation of differentiation clusters’ and endoglin markers preset in porcine buccal mucosa cells

Abstract Several genes, namely CD44, CD90, CD105 and PCNA may be important in differentiation of porcine mucosa cell cultures. These genes are, inter alia, responsible for cell adhesion to extracellular matrix and its constituent secretion, cytoskeleton organization, epithelial to mesenchymal transition or proper course of DNA replication. A total of 20 pubertal crossbred Landrace gilts bred on commercial farms were used to produce buccal mucosa cultures, which were harvested on the 7th, 15th and 30th day after initiation of the culture. Expression levels of CD44, CD90, CD105 and PCNA were evaluated employing Real-Time Quantitative Polymerase Chain Reaction. CD44, CD90 and PCNA showed an unchanged expression pattern. Expression of CD44 on day 7 was the highest of all factors measured. The greatest difference between the measurement on 7th and 30th day was found in the PCNA gene. These results broaden the understanding of the transcriptome changes in porcine buccal mucosa cells for the duration of in vitro cultivation. Nevertheless, it is very important to consider that the in vitro conditions do not fully reflect the changes taking place in the living organism. It appears that tissues of the oral cavity possess high regenerative potential, and constitute suitable model for wound healing investigation. Running title: Confirmation of differentiation clusters’ and endoglin markers preset in porcine buccal mucosa cells

Effect of Acrylamide Supplementation on the Population of Vasoactive Intestinal Peptide (VIP)-Like Immunoreactive Neurons in the Porcine Small Intestine.

Acrylamide is one of the harmful substances present in food. The present study aimed to establish the effect of acrylamide supplementation in tolerable daily intake (TDI) dose (0.5 µg/kg b.w./day) and a dose ten times higher than TDI (5 µg/kg b.w./day) on the population of vasoactive intestinal peptide-like immunoreactive (VIP-LI) neurons in the porcine small intestine and the degree of the co-localization of VIP with other neuroactive substances (neuronal nitric oxide synthase (nNOS), substance P (SP), and cocaine- and amphetamine-regulated transcript peptide (CART)). In our work, 15 Danish landrace gilts (5 in each experimental group) received capsules (empty or with low or high doses of acrylamide) for a period of 28 days with their morning feeding. Using double immunofluorescence staining, we established that acrylamide supplementation increased the number of neurons showing immunoreactivity towards VIP in all types of enteric nervous system (ENS) plexuses and fragments of the small intestine studied. Moreover, both doses of acrylamide led to changes in the degree of co-localization of VIP with nNOS, SP, and CART in intramural neurons. The observed changes may be the adaptation of neurons to local inflammation, oxidative stress, or the direct toxic effects of acrylamide on intestinal neurons, also referred to as neuronal plasticity.

45 A permutation test for validation of genomic estimated breeding values

Abstract Previous studies have shown that the accuracy of Genomic Estimated Breeding Value (GEBV) as a predictor of future performance is higher than the traditional Estimated Breeding Value (EBV). The purpose of this study was to estimate the potential advantage of selection on GEBV for litter size (LS) compared to selection on EBV in the Canadian swine dam line breeds. The study included 236 Landrace and 210 Yorkshire gilts born in 2017 which had their first farrowing after 2017. GEBV and EBV for LS were calculated with data that was available at the end of 2017 (GEBV2017 and EBV2017, respectively). De-regressed EBV for LS in July 2019 (dEBV2019) was used as an adjusted phenotype. The average dEBV2019 for the top 40% of sows based on GEBV2017 was compared to the average dEBV2019 for the top 40% of sows based on EBV2017. The standard error of the estimated difference for each breed was estimated by comparing the average dEBV2019 for repeated random samples of two sets of 40% of the gilts. In comparison to the top 40% ranked based on EBV2017, ranking based on GEBV2017 resulted in an extra 0.45 (±0.29) and 0.37 (±0.25) piglets born per litter in Landrace and Yorkshire replacement gilts, respectively. The estimated Type I errors of the GEBV2017 gain over EBV2017 were 6% and 7% in Landrace and Yorkshire, respectively. Considering selection of both replacement boars and replacement gilts using GEBV instead of EBV can translate into increased annual genetic gain of 0.3 extra piglets per litter, which would more than double the rate of gain observed from typical EBV based selection. The permutation test for validation used in this study appears effective with relatively small data sets and could be applied to other traits, other species and other prediction methods.

10.4314/sajas.v40i5.65262

In a 2 x 2 factorial design, attainment of puberty in 32 Black Indigenous (BI) and 60 SA Landrace (SAL) gilts was studied under the effects of two treatment diets fed individually ad libitum. Treatment 1 contained 160 g CP and 13.6 MJ DE/kg DM, and Treatment 2, a 25% dilute of Treatment 1 using wood shavings, contained 120 g CP and 10.2 MJ DE/kg DM. Target weights set for BI gilts were from 10 to 50 kg and for SAL, 15 to 120 kg. A sample was slaughtered at each target weight. Reproductive organs were removed, measured and the number, size and physiological state of follicles recorded. Carcasses were deboned and the soft tissue analysed for moisture, protein and fat content. Treatments affected growth significantly. Cumulative mass (lnkg) was regressed against cumulative ME intake (lnME) with b the allometric coefficient in a linear autoregressive model. A change in b indicated a change or breakpoint of physiological development. Puberty was taken to coincide with the breakpoint. Age and weight at puberty differed by treatment for each genotype. Estimated live weight fat (percentage) and carcass fat (percentage) at these ages show a close range between genotypes and treatment diets.

Transcriptomic profile of genes encoding proteins responsible for regulation of cells differentiation and neurogenesis in vivo and in vitro – an oocyte model approach

Abstract The growth and development of the oocyte is essential for the ovarian follicle. Cumulus cells (CCs) - a population of granulosa cells - exchange metabolites, proteins and oocyte-derived paracrine factors with the oocyte through gap junctions, to contribute to the competency and health of the oocyte. This bi-directional communication of the cumulus-oocyte complex could be better understood through the micro-analysis of a porcine oocyte gene expression before in vitro maturation (IVM) and after. Additionally, the study of the somatic and gamete cells differentiation capability into neuronal lineage would be promising for future stem cell research as granulosa cells are easily accessible waste material from in vitro fertilization (IVF) procedures. Therefore, in this study, the oocytes of 45 pubertal Landrace gilts were isolated and the protein expression of the COCs were analyzed through micro-analysis techniques. Genes belonging to two ontological groups: neuron differentiation and negative regulation of cell differentiation have been identified which have roles in proliferation, migration and differentiation. Twenty identified porcine oocyte genes (VEGFA, BTG2, MCOLN3, EGR2, TGFBR3, GJA1, FST, CTNNA2, RTN4, MDGA1, KIT, RYK, NOTCH2, RORA, SMAD4, ITGB1, SEMA5A, SMARCA1, WWTR1 and APP) were found to be down-regulated after the transition of IVM compared to in vitro. These results could be applied as gene markers for the proliferation, migration and differentiation occurring in the bi-directional communication between the oocyte and CCs. Running title: Differentiation and neurogenesis in oocyte cells

The processes of homeostasis, chemotaxis and organic and inorganic response are significantly up-regulated during short-term oral mucosal cells in vitro cultivation

Abstract Mucous membranes appear in various parts of the whole body performing similar functions. However, they differ based on where the mucosa is located. It functions as a barrier in such systems as: respiratory, urogenital and digestive . In this study we will be focusing strictly on the oral mucosa. Keratinocytes and fibroblasts, which mainly form the structure of the oral mucosa, are subjected to numerous factors. Being one of the million parts that build the animal organism, they are involved in various processes. In this study, we will try to confirm that in the in vitro culture of oral mucosa cells, the expression of our selected genes undergoes significant changes which are tied to such processes as: homeostasis, chemotaxis and organic/inorganic response of the organism. For this study, 20 pubertal crossbred Landrace gilts were used. After slaughter, samples of buccal pouch mucosa were obtained and transported to the laboratory. The excised tissue was prepared and processed due to protocols. The final pellet was resuspended in supplemented DMEM. Once the cultures attained 70–80% confluency, they were passaged. Total RNA from each pooled sample was subjected to two rounds of sense cDNA amplification. The cDNA was processed on microarrays. Analysis of the scanned arrays was performed. The files were imported into downstream data analysis software. The DAVID analysis showed that differently expressed genes belongs to 56 Gene ontology groups. In this paper we focused on “cellular divalent inorganic cation homeostasis”, “chemical homeostasis”, “chemotaxis”, “homeostatic process” and “response to organic substance” GO BP terms. These sets of genes were subjected to hierarchical clusterization procedure. In summary, the data we collected showed primarily changes in gene expression that occurred in the thirty-day cell culture of oral mucosa tissue. We assume that indicated genes could be new gene markers for studied processes. Running title: Homeostasis in oral mucosa cells

Computed tomography evaluation of gilt growth performance and carcass quality under feeding restrictions and compensatory growth effects on the sensory quality of pork

Restricted feed can affect the body composition of pigs. Body composition can be studied non-destructively in live pigs using computed tomography (CT). The objective was to investigate the effect of different feeding restriction strategies on the productive and carcass quality parameters of gilts during growth via CT images and the effects of such strategies on meat quality, sensory properties and consumer preferences. Moreover, we sought to determine whether CT is a suitable tool for this purpose in this type of study. Thus, 36 Pietrain x (Large White x Landrace) gilts were assigned to the following three feeding strategies: 1) ad libitum feeding (AL) during all fattening periods (AL-AL); 2) AL feeding between 30 and 70 kg target body weight (TBW) followed by restriction (84% of AL) until 120 kg TBW (AL-RV); and 3) restriction feeding (78% of AL) between 30 and 70 kg TBW followed by AL until 120 kg TBW (RV-AL). When the pigs reached 30, 70, 100 and 120 kg, they were CT scanned to obtain the carcass composition parameters. At 120 kg TBW, the pigs were slaughtered, and the carcass and meat quality was determined. The loins were collected for trained panel evaluation and consumer tests. The panellists evaluated the odour, flavour and texture attributes of cooked loins. A total of 120 consumers scored the overall acceptability, tenderness, odour and flavour. The results showed a decrease of 76% and 80% in the average daily gain and average daily feed intake during the restriction period compared with the ad libitum in the growth phase, respectively, and a decrease of 89% and 87% in these parameters during the fattening phase, respectively. A restriction reduces the body fat content during the period of the restriction. Differences in the carcass and cut composition and meat quality were not observed at the end of the experiment among the treatments. Regarding sensory quality, meat from the animals in the AL-AL treatment was tougher than that from animals in the RV-AL and AL-RV treatments. Nevertheless, these differences were not detected by consumers, who did not provide significantly different scores for acceptability. Thus, when preparing feeding strategies, these results should be considered to optimize costs and increase benefits. Furthermore, computed tomography represents a non-destructive technology suitable for determining carcass composition before slaughter.

Genetic and genomic characterization of vulva size traits in Yorkshire and Landrace gilts

BackgroundReproductive performance is critical for efficient swine production. Recent results indicated that vulva size (VS) may be predictive of reproductive performance in sows. Study objectives were to estimate genetic parameters, identify genomic regions associated, and estimate genomic prediction accuracies (GPA) for VS traits.ResultsHeritability estimates of VS traits, vulva area (VA), height (VH), and width (VW) measurements, were moderately to highly heritable in Yorkshire, with 0.46 ± 0.10, 0.55 ± 0.10, 0.31 ± 0.09, respectively, whereas these estimates were low to moderate in Landrace, with 0.16 ± 0.09, 0.24 ± 0.11, and 0.08 ± 0.06, respectively. Genetic correlations within VS traits were very high for both breeds, with the lowest of 0.67 ± 0.29 for VH and VW for Landrace. Genome-wide association studies (GWAS) for Landrace, reveled genomic region associated with VS traits on Sus scrofa chromosome (SSC) 2 (154–157 Mb), 7 (107–110 Mb), 8 (4–6 Mb), and 10 (8–19 Mb). For Yorkshire, genomic regions on SSC 1 (87–91 and 282–287 Mb) and 5 (67 Mb) were identified. All regions explained at least 3.4% of the genetic variance. Accuracies of genomic prediction were moderate in Landrace, ranging from 0.30 (VH) to 0.61 (VA), and lower for Yorkshire, with 0.07 (VW) to 0.11 (VH). Between-breed and multi-breed genomic prediction accuracies were low.ConclusionsOur findings suggest that VS traits are heritable in Landrace and Yorkshire gilts. Genomic analyses show that major QTL control these traits, and they differ between breed. Genomic information can be used to increase genetic gains for these traits in gilts. Additional research must be done to validate the GWAS and genomic prediction results reported in our study.

Transcriptomic analysis of expression of genes regulating cell cycle progression in porcine ovarian granulosa cells during short-term in vitro primary culture

The primary function of ovarian granulosa cells (GCs) is the support of oocytes during maturation and development. Molecular analyses of granulosa cell-associated processes, leading to improvement of understanding of the cell cycle events during the formation of ovarian follicles (folliculogenesis), may be key to improve the in vitro fertilization procedures. Primary in vitro culture of porcine GCs was employed to examine the changes in the transcriptomic profile of genes belonging to “cell cycle”, “cell division”, “cell cycle process”, “cell cycle phase transition”, “cell cycle G1/S phase transition”, “cell cycle G2/M phase transition” and “cell cycle checkpoint” ontology groups. During the analysis, microarrays were employed to study the transcriptome of GCs, analyzing the total RNA of cells from specific periods of in vitro cultures. This research was based on material obtained from 40 landrace gilts of similar weight, age and the same living conditions. RNA was isolated at specific timeframes: before the culture was established (0 h) and after 48 h, 96 h and 144 h in vitro. Out of 133 differentially expressed genes, we chose the 10 most up-regulated (SFRP2, PDPN, PDE3A, FGFR2, PLK2, THBS1, ETS1, LIF, ANXA1, TGFB1) and the 10 most downregulated (IGF1, NCAPD2, CABLES1, H1FOO, NEK2, PPAT, TXNIP, NUP210, RGS2 and CCNE2). Some of these genes known to play key roles in the regulation of correct cell cycle passage (up-regulated SFRP2, PDE3A, PLK2, LIF and down-regulated CCNE2, TXNIP, NEK2). The data obtained provide a potential reference for studies on the process of mammalian folliculogenesis, as well as suggests possible new genetic markers for cell cycle progress in in vitro cultured porcine granulosa cells.

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

Abstract 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 &amp;lt; 0.05) and lost more backfat (P &amp;lt; 0.05) than CTL gilts during treatment. There was a treatment x day effect (P &amp;lt; 0.01) on IGF-1, glucose and urea concentrations in blood. Concentrations of IGF-1 increased fourfold (P &amp;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 &amp;lt; 0.01) and 103 (P = 0.01), and tended to be greater (P &amp;lt; 0.10) on day 109 of gestation in pST gilts. Glucose was greater in pST than CTL gilts on days 96 (P &amp;lt; 0.01), 103 (P &amp;lt; 0.01) and 109 (P = 0.01). Injections of pST did not affect weight of mammary extraparenchyma (P &amp;gt; 0.10) but increased mammary parenchymal mass (1922.2 vs 1576.1 ± 123.9 g, P &amp;lt; 0.05). Mammary parenchyma contained more (P &amp;lt; 0.05) protein, DNA and RNA and less fat (P &amp;lt; 0.05) and dry matter (P &amp;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.

68 Genomic prediction accuracies of vulva size traits in Landrace and Yorkshire gilts

Abstract Recent results indicated that vulva size measured prior to puberty may be predictive of reproductive performance in sows. Therefore, the objective of this study was to estimate genomic prediction accuracies for vulva size traits in purebred gilts. A total of 1,185 Landrace (n = 477) and Yorkshire (n = 708) gilts originated from two different lines were used in this study. All animals had vulva size measurements taken at an average 21.5 weeks of age (SD = 5.8). Measurements included vulva width (VW), vulva height (VH), and vulva area (VA). Genotype data (Geneseek GGP-HD) was available for all animals, for ~40K SNPs. Marker allele substitution effects were estimated using Bayes-B (pi = 0.99) in a model including the fixed effects of contemporary group, line, breed (for multi-breed analysis only) and body weight (covariate), and the random effect of SNPs. Genomic prediction accuracies were estimated using three training and validation strategies: between-breed, within-breed (4 and 6 cross-validation folds for Landrace and Yorkshire, respectively), and multi-breed (10-fold cross-validation, using one-fold per breed for validation at a time). Between-breed accuracies were low and consistently negative, with -0.02, -0.10, and -0.05 in Landrace and -0.05, -0.04 and -0.03 in Yorkshire, for VW, VH, and VA, respectively. Within Landrace, these were moderate, with 0.35 (VW), 0.42 (VH), and 0.56 (VA), whereas lower accuracies were obtained for Yorkshire, with 0.07 (VW), 0.20 (VH), and 0.14 (VA). Multi-breed accuracies were low with 0.14 (VW), 0.14 (VH), and 0.24 (VA) for Landrace, and 0.03 (VW), 0.16 (VH), and 0.09 (VA) for Yorkshire. These results indicate that genomic selection for vulva size traits is possible in Landrace, but limited in Yorkshire gilts. The low between- and multi-breed results suggest that QTL for these traits are in opposite phases between breeds and/or do not segregate in both breeds. Financial support from the Iowa Pork Industry Center is appreciated.