Higher Backfat Research Articles

Konjac flour-mediated gut microbiota alleviates insulin resistance and improves placental angiogenesis of obese sows

Our previous study revealed that dietary konjac flour (KF) could remodel gut microbiota and improve reproductive performance of sows, but its underlying mechanisms remain unclear. This experiment aimed to investigate how dietary KF improves reproductive performance of obese sows. Here, 60 sows were assigned into three groups according to their backfat thickness: normal backfat sows fed with control diet (CON-N), high backfat sows fed with control diet (CON-H) and high backfat sows fed with KF inclusion diet (KF-H). The characteristics of sows and piglets were recorded. Next, fecal microbiota transplantation (FMT) was performed on female mice, followed by recording the characteristics of female mice. The results showed that compared with CON-H group, KF-H group showed downtrend in stillbirth rate (P = 0.07), an increase in placental efficiency (P < 0.01) and average piglet weight (P < 0.01); coupled with a decrease in the values of homeostasis model assessment-insulin resistance (P < 0.01); as well as an increase in placental vascular density and protein expression of angiogenesis markers (P < 0.01). As expected, sows fed KF diets had improved abundance and diversity of gut microbiota. More importantly, compared with CON-H(FMT) group, KF-H(FMT) group showed improvement in reproductive performance and insulin sensitivity (P < 0.05), as well as an increase in placental labyrinth zone and protein expression of angiogenesis markers (P < 0.05). Furthermore, we found a content increase (P < 0.05) of SCFAs in both KF-H group sow and KF-H (FMT) group mice. Overall, KF supplementation could alleviate insulin resistance, promote placental angiogenesis, and ultimately improve the reproductive performance of sows via gut microbiota remodeling.

Pen Versus Crate: A Comparative Study on the Effects of Different Farrowing Systems on Farrowing Performance, Colostrum Yield and Piglet Preweaning Mortality in Sows under Tropical Conditions.

The present study was performed to determine the farrowing performance of sows, newborn piglet characteristics, colostrum yield, milk yield and piglet preweaning mortality in a free-farrowing pen compared to a conventional farrowing crate system in a tropical environment. A total of 92 sows and 1344 piglets were included in the study. The sows were allocated by parity into two farrowing systems, either a free-farrowing pen (n = 54 sows and 805 piglets) or a crate (n = 38 sows and 539 piglets). Backfat thickness and loin muscle depth of sows at 109.0 ± 3.0 days of gestation were measured. Reproductive performance data including total number of piglets born (TB), number of piglets born alive (BA), percentage of stillborn piglets (SB) and percentage of mummified foetuses (MF) per litter, farrowing duration, piglet expulsion interval, time from onset of farrowing to the last placental expulsion, piglet preweaning mortality rate, percentage of piglets crushed by sows and number of piglets at weaning were analysed. In addition, piglet colostrum intake, colostrum yield, Brix index and milk yield of sows were evaluated. On average, TB, BA, farrowing duration, colostrum yield and milk yield during 3 to 10 and 10 to 17 days of lactation were 14.7 ± 2.8, 12.8 ± 3.1, 213.2 ± 142.2 min, 5.3 ± 1.4 kg, 8.6 ± 1.5 kg, and 10.4 ± 2.2 kg, respectively. Sows kept in the free-farrowing pen tended to produce more colostrum than crated sows (5.5 ± 0.2 vs. 4.9 ± 0.2 kg, p = 0.080). Piglets born in the free-farrowing pen had a higher colostrum intake than those in the crate system (437.0 ± 6.9 and 411.7 ± 8.3 g, p = 0.019). However, the piglet preweaning mortality rate (26.8 ± 2.9 vs. 17.0 ± 3.8, p = 0.045) and the proportion of piglets crushed by sows (13.1 ± 2.1 vs. 5.8 ± 2.7, p = 0.037) in the free-farrowing pen were higher than those in the crate system. Interestingly, in the free-farrowing pen, piglet preweaning mortality rate in sows with high backfat thickness was higher than that in sows with moderate (37.8 ± 5.1% vs. 21.6 ± 3.6%, p = 0.011) and low (21.0 ± 6.2%, p = 0.038) backfat thickness. Moreover, the incidence of crushing in sows with high backfat thickness was higher in the free-farrowing pen than in the crate system (17.6 ± 3.6 vs. 4.0 ± 5.7, p = 0.049), but this difference was not detected for sows with moderate and low backfat thickness (p &gt; 0.05). Milk yield of sows during 3 to 10 days (8.6 ± 0.2 vs. 8.6 ± 2.3, p &gt; 0.05) and 10 to 17 days (10.2 ± 0.3 vs. 10.4 ± 0.4, p &gt; 0.05) did not differ between the two farrowing systems. In conclusion, piglets born in the free-farrowing pen had a higher colostrum intake than those in the crate system. However, the piglet preweaning mortality rate and the proportion of piglets crushed by sows in the free-farrowing pen were higher than in the crate system. Interestingly, a high proportion of piglet preweaning mortality in the free-farrowing system was detected only in sows with high backfat thickness before farrowing but not in those with low and moderate backfat thickness. Therefore, additional management in sows with high backfat thickness (&gt;24 mm) before farrowing should be considered to avoid the crushing of piglets by sows.

Preliminary identification and analysis of differential RNA editing between higher and lower backfat thickness pigs using DNA-seq and RNA-seq data.

RNA editing is an essential post-transcriptional regulatory mechanism. However, few studies have investigated the functional RNA edits in the economic traits of livestock on a genome-wide scale. Pigs are one of the most important livestock species and their fat is the principal organ involved in the regulation of adipose deposition. Here, we used three full-sibling pairs, with each pair comprising a pig with higher backfat (BF) thickness and lower backfat thickness, to identify RNA editing events based on whole-genome and transcriptome sequencing data. A total of 60,903 non-redundant RNA editing sites with 59,472 (97.7%) A-to-G edits were detected using a revised bioinformatics pipeline. A specific sequence context with G preference was found one base downstream of the edited site, and the editing level was associated with the distribution of nucleotides across nearly sites. Moreover, the A-to-G editing sites mostly occurred in the pig-special short interspersed nuclear elements, Pre0_SS. Comparing the difference between pigs with higher BF and lower BF, we found 211 differentially edited sites (DESites). Functional enrichment analyses revealed a significant enrichment of genes containing DESites in terms of adipose deposition. The DESites located in the six adipose-related genes (SKP1, GSK3B, COL5A3, MDM4, NT5C2, and DENND2A) were selected as candidate RNA editing sites associated with adipose deposition, and thus require further evaluation. This study mined the potentially functional RNA editing sites in pig adipose tissue and indicated that RNA editing may play an important role in adipose deposition, which provides a new insight into the post-transcriptionally mediated regulation mechanism of fat development.

Identification of candidate genes that specifically regulate subcutaneous and intramuscular fat deposition using transcriptomic and proteomic profiles in Dingyuan pigs

Subcutaneous fat and intramuscular fat (IMF) deposition are closely related to meat production and pork quality. Dingyuan pig, as a native pig breed in China, low selection leads to obvious genetic and phenotypic differences in the population. Individuals with extreme fat content in the population are ideal models for studying the mechanism of fat deposition. In this study, we used RNA-Seq and tandem mass tags-based (TMT) proteomics to analyze the key pathways and genes that specifically regulate subcutaneous fat and IMF deposition in Dingyuan pigs. We identified 191 differentially expressed genes (DEGs) and 61 differentially abundant proteins (DAPs) in the high and low back fat thickness (HBF, LBF) groups, 85 DEGs and 12 DAPs were obtained in the high and low intramuscular fat (HIMF, LIMF) groups. The functional analysis showed that the DEGs and DAPs in the backfat groups were mainly involved in carbohydrates, amino acids, and fatty acids metabolism, whereas the IMF groups were involved in the insulin pathway, longevity, and some disease-related pathways. We found 40 candidate genes that might tissue-specifically lipids deposition for subcutaneous and intramuscular fat. Our research provides theoretical reference materials for the improvement of fat deposition traits of local pig breeds in my country.

Open Cows in a Beef Cattle Enterprise Managed in a Seasonal Breeding Program? An Appraisal of Their Reproductive Performance Based on Body Fat Reserves

A comparison between two distinct levels of back fat thickness in open cows, females not becoming pregnant during the previous breeding season, was carried out in order to evaluate their reproductive performance prior to the next natural mating in a seasonal breeding program. Thirty open cows from the previous breeding season were divided evenly by age and back fat thickness (BFT) in two groups. HBFT (high back fat thickness ≥ 70 mm) and LBFT (low back fat thickness ≤ 70 mm), values statistically different between groups (P < 0.05). The study was divided into three phases in which the formation of CL and follicular dynamics were recorded by ultrasound and progesterone. Also, serial monitoring of glucose, urea and triglycerides and back fat thickness were studied. A fertile bull previously approved from a breeding soundness evaluation was introduced after the third phase and remained with the herd for 90 days. No differences were found in the follicular dynamics; the number of animals cycling in the two groups and fertility were also similar (80%). Differences in urea and triglycerides were found in cows with high scores of BFT. In conclusion, the decision of keeping open cows to the next breeding season must be based on an economical advantage to the farmer.

Sow-related factors affecting the postweaning feed intake in Landrace × Large White females.

During the weaning-to-estrus interval (WEI), a high feeding level is usually offered to recover losses due to lactational catabolism. However, several factors can affect the appetite, possibly impairing the efficacy of this strategy. This study aimed to investigate the effect of sow-related factors on average daily feed intake (ADFI) during WEI in 142 primiparous and 458 multiparous sows. After weaning, the sows received 4.3 kg/day of feed and the wastage was recorded. The ADFI after weaning was lower in primiparous than multiparous sows, and on estrous day than in 2 and 3 days preceding estrus (P ≤ 0.05). In primiparous sows, lower ADFI was observed if they had higher backfat thickness at 112 days of gestation (BFT ≥ 11.5 mm) or higher reserves at weaning (BFT ≥ 10.5 mm, caliper units ≥ 12 or ≥ 157 kg; P ≤ 0.05). Higher body reserves at the end of gestation (caliper units ≥ 12, BFT ≥ 11.0 mm, or BCS ≥ 3.0) or weaning (caliper units ≥ 13, BFT ≥ 12.5 mm) negatively affected the ADFI in multiparous sows (P < 0.04). Weaned litter size ≤ 11 piglets (P = 0.06) and shorter lactation length (P< 0.01) decreased the ADFI in primiparous sows. Greater loss in caliper units during lactation tended to reduce ADFI in primiparous and multiparous sows (P ≤ 0.07). Multiparous sows with greater losses in BFT and BCS had lower ADFI (P ≤ 0.03). The ADFI during WEI is reduced when sows are in estrus or if they have greater body reserves.

MiR-144-3p Targets FoxO1 to Reduce Its Regulation of Adiponectin and Promote Adipogenesis.

MicroRNAs (miRNAs), as a series of important short-chain non-coding RNAs, play an important post-transcriptional role in many biological activities, including adipogenesis. miR-144 is significantly upregulated in type II diabetes (T2D), and is considered to be an important biomarker for T2D. However, although the occurrence of T2D is inextricably linked to adipogenesis, whether miR-144 directly regulates adipogenesis remains to be further explored. In this paper, we demonstrate that miR-144 has a higher expression level in a porcine high backfat group, and it has a significant positive effect on promoting the differentiation of pre-adipocytes. FoxO1 is a target gene of miR-144, and inhibits the differentiation of pre-adipocytes. On the other hand, we demonstrate that FoxO1 can bind to the AdipoQ gene promoter, then regulate the AdipoQ expression by binding to the FoxO1 binding site in the AdipoQ promoter -1,499 to -1,489 bp and -1,238 to -1,228 bp regions, especially the -1,499 to -1,489 bp region. Meanwhile, miR-144 and FoxO1 co-expressional research has also shown that both factors regulate adipogenesis. To sum up, our research indicates that miR-144 targets FoxO1, thus reducing its expression and inhibiting its promotional effect on adiponectin, thereby alleviating the inhibitory effect of adiponectin on adipogenesis.

Factors influencing pre-ovulatory follicle diameter and weaning-to-ovulation interval in spontaneously ovulating sows in tropical environment.

Follicle development and timing of ovulation are indicators of the reproductive performance of sows. The present study aimed to determine factors influencing pre-ovulatory follicle diameter and weaning-to-ovulation interval (WOI) in spontaneously ovulating sows in tropical climates with special emphasis on breed, parity and backfat thickness at weaning. In total, 80 sows were included in the study. Follicle development was determined by using transrectal real-time B-mode ultrasonography every 6hr after standing oestrus. Weaning-to-oestrous interval (WEI), oestrous-to-ovulation interval (EOI), WOI and the diameter of graafian follicles were investigated in relation to breed, parity number (1, 2-3 and 4-7) and backfat thickness (low, moderate and high) of sows. Overall, WEI, EOI, WOI and the pre-ovulatory follicle diameter were 92.5±21.6hr, 64.3±19.3hr, 156.3±29.1hr and 10.3±2.0mm, respectively. Pre-ovulatory follicle size was smaller in primiparous sows compared with sows of greater parity, 4-7 (9.7±0.51 and 11.7±0.52mm, respectively, p<.05). Weaning-to-ovulation interval was positively correlated with WEI (r=0.75, p<.001) and EOI (r=0.66, p<.001), but negatively correlated with size of the graafian follicle (r=-0.34, p<.01). Sows with a shorter WEI had a larger pre-ovulatory follicle diameter (at 64hr after oestrus) (r=-0.37, p<.01). Sows with low backfat thickness had a WOI 23.4hr longer than those with moderate backfat thickness (p<.05) and 17.6hr longer than sows with a high backfat thickness (p=.140). The follicle diameter in primiparous sows with high backfat thickness (11.7±1.1mm) was higher than in those with low (8.9±0.7mm, p<.05) or moderate (8.6±0.8, p<.05) backfat thickness. In conclusion, factors influencing follicle diameter and WOI in sows included parity number and backfat thickness at weaning. The impact of backfat thickness on follicle diameter, WEI and WOI was most pronounced in primiparous sows.

Effect of backfat thickness during late gestation on farrowing duration, piglet birth weight, colostrum yield, milk yield and reproductive performance of sows

Sow milk is important for the survival and growth of suckling piglets. The reserved backfat of sows during late gestation may influence foetal development and milk synthesis. We investigated the effect of backfat thickness of sows at 109 days of gestation on farrowing duration, piglet birth weight, colostrum yield, milk yield and reproductive performance, using 73 sows and 1,291 piglets. Backfat thickness was measured when the sows entered the farrowing house at 109 days of gestation, using A-mode ultrasonography, and sows were classified into three groups: LOW (≤12.5 mm, n = 24), MODERATE (13 to 15 mm, n = 30) and HIGH (≥15.5 mm, n = 19). Sow parameters included backfat thickness at 10, 17 and 21 days postpartum, backfat loss during lactation, farrowing duration, total number of piglets born per litter (TB) and number of piglets born alive per litter (BA), proportion of stillborn piglets (SB) and mummified foetuses per litter (MM). Piglet parameters consisted of the birth interval and body weight of the piglets at 0,1,3,10 and 17 days postpartum. Colostrum intake of the piglets, colostrum yield and milk yield from days 3–10 and 10–17 of lactation were calculated and compared among groups of sows with different backfat thickness at 109 days of gestation. Farrowing duration and birth interval were 275.0 ± 187.5 and 14.8 ± 27.1 min, respectively. Both the duration of farrowing and the birth interval did not differ among sows with LOW, MODERATE and HIGH backfat thickness (P>0.05). Piglet weight at birth, TB, BA and MM did not differ among groups (P>0.05). However, SB in sow with LOW backfat thickness at 109 days of gestation was higher than sows with MODERATE (P = 0.024) backfat thickness. The proportion of stillborn piglets per litter in sow parities 3 to 6 was higher than in parities 1 and 2 (P<0.05). The highest SB was observed in sow parities 3 to 6 with low backfat thickness. Milk yield of sows between 3 and 10 days of lactation increase as backfat thickness at day 109 of gestation increased (r = 0.32, P = 0.008). However, backfat thickness at 109 days of gestation was negatively correlated with backfat loss during lactation (r=-0.42, P<0.001). Backfat thickness increase by 1.0 mm at day 109 of gestation resulted in an increased milk yield between 3 and 10 days of 271 g per day (P = 0.008). Backfat thickness of sows at 109 days of gestation influenced milk yield during 3 to 10 days of lactation and SB in sow parity numbers 3 to 6. However, high backfat thickness resulted in a high backfat loss during lactation.

Transcriptome analysis of miRNA and mRNA in the livers of pigs with highly diverged backfat thickness

Fat deposition is very important in pig production, and its mechanism is not clearly understood. MicroRNAs (miRNAs) play critical roles in fat deposition and energy metabolism. In the current study, we investigated the mRNA and miRNA transcriptome in the livers of Landrace pigs with extreme backfat thickness to explore miRNA-mRNA regulatory networks related to lipid deposition and metabolism. A comparative analysis of liver mRNA and miRNA transcriptomes from pigs (four pigs per group) with extreme backfat thickness was performed. We identified differentially expressed genes from RNA-seq data using a Cufflinks pipeline. Seventy-one differentially expressed genes (DEGs), including twenty-eight well annotated on the porcine reference genome genes, were found. The upregulation genes in pigs with higher backfat thickness were mainly involved in fatty acid synthesis, and included fatty acid synthase (FASN), glucokinase (GCK), phosphoglycerate dehydrogenase (PHGDH), and apolipoprotein A4 (APOA4). Cytochrome P450, family 2, subfamily J, polypeptide 34 (CYP2J34) was lower expressed in pigs with high backfat thickness, and is involved in the oxidation of arachidonic acid. Moreover, 13 differentially expressed miRNAs were identified. Seven miRNAs were associated with fatty acid synthesis, lipid metabolism, and adipogenic differentiation. Based on comprehensive analysis of the transcriptome of both mRNAs and miRNAs, an important regulatory network, in which six DEGs could be regulated by differentially expressed miRNAs, was established for fat deposition. The negative correlate in the regulatory network including, miR-545-5p and GRAMD3, miR-338 and FASN, and miR-127, miR-146b, miR-34c, miR-144 and THBS1 indicate that direct suppressive regulation may be involved in lipid deposition and energy metabolism. Based on liver mRNA and miRNA transcriptomes from pigs with extreme backfat thickness, we identified 28 differentially expressed genes and 13 differentially expressed miRNAs, and established an important miRNA-mRNA regulatory network. This study provides new insights into the molecular mechanisms that determine fat deposition in pigs.

The Effects of Maternal Obesity on Porcine Placental Efficiency and Proteome.

Simple SummaryThe placenta plays an important role in the growth and development of a fetus and in maintaining a healthy pregnancy. The placenta is also sensitive to suboptimal intrauterine conditions, such as maternal obesity. Although previous studies have indicated that maternal obesity is associated with placental dysfunction, we are still far from elucidating the molecular mechanisms underlying this phenomenon. In this study, proteomic technique was employed to compare the proteomic profiles of the placentas of sows with different backfat thicknesses. We revealed that excessive backfat of sow is associated with abnormal carbohydrate and lipid metabolism, mitochondrial dysfunction, and increased oxidative stress and inflammation in the placenta. Our results promote the understanding of decreased placental efficiency induced by maternal obesity.Maternal obesity is associated with impaired maternal metabolism and affects the developmental programming of the fetus. The placenta is dysfunctional when exposed to an obese intrauterine environment and can transduce and mediate detrimental maternal impacts to the fetus through mechanisms that remain largely unknown. The main objective of this study was to investigate the effects of maternal obesity on the porcine placental proteome and to analyze the deregulated proteins and potential pathways predicted to be disturbed in obese placentas, using sows with high backfat as a model of obese pregnancy. The sows were divided into two groups based on their backfat thickness: normal backfat (NBF, 17–22 mm; n = 30) and high backfat (HBF, ≥23 mm; n = 30) as the maternal obesity group. The placental tissues used for the proteomic and biochemical analyses were obtained through vaginal delivery, and the maternal blood samples used to determine the metabolic parameters were collected at day 107 of pregnancy. Our study demonstrated that HBF sows had significantly decreased placental efficiency, increased plasma-free fatty acids and triglyceride levels, and increased proinflammatory cytokines plasma levels (p < 0.05). HBF placentas had significantly higher malondialdehyde level, lower total antioxidant capacity and antioxidase activity, increased triglyceride content and enhanced proinflammatory tumor necrosis factor- α (TNF-α) and interleukin-6 (IL-6) contents (p < 0.05). Among the 4652 proteins identified using the proteomic method, 343 were quantified as differentially abundant proteins, which were involved in many vital biological processes. Based on our bioinformatic and placental biochemical analyses, we concluded that maternal obesity is associated with abnormal carbohydrate and lipid metabolism, mitochondrial dysfunction, decreased steroid hormone biosynthesis, and increased oxidative stress and inflammation in the placenta. The results of this study are undoubtedly valuable to other researchers.

Effects of Protein Restriction on Performances and Meat Quality of Cinta Senese Pig Reared in an Organic System.

Simple SummaryFat contained in meat is an important contributor to sensory traits: it increases meat tenderness and flavor. In commercial pigs, increasing meat’s fat was obtained by feeding, until the fattening period, a diet slightly lower in protein respect to their requirements. Local pig breeds, such as Cinta Senese, are known as obese pigs because their great potential to deposit fat, which is mainly stored in backfat deposits. This study was aimed to assess if protein restriction in growing can further increase meat’s fat without alter overall body fatness of obese pigs. The normal feeding management and the restricted one were compared in two groups of Cinta Senese pigs. Results showed that protein restriction during the growing phase affected only few traits. The restricted animal was more able to use the protein in feeding, but few modifications were found in the chemical composition of meat, including the meat’s fat, that remained unchanged. So, obese genotype might be less responsive to this kind of feeding management.In lean genotypes, protein restriction during growing increases intramuscular fat content without affecting the overall carcass fatness. The present study aims to assess the feasibility of applying this feeding management on an obese pig, the Cinta Senese, since obese genotypes are characterized by great lipogenic potential often leading to excessively high backfat deposits. Twenty pigs of average weight 38 kg, were divided in two groups, the first group was fed a protein restricted diet (9% of crude protein), while the second one a normal diet (13.5% of crude protein). During finishing, both groups were fed the same diet (10% of crude protein). Average daily gain, protein conversion index, backfat thickness, carcass weight, and prime cuts were determined. A loin sample joint was dissected in intermuscular fat, bone, subcutaneous fat, longissimus lumborum, and psoas major. On longissimus lumborum, physical and chemical analysis was carried out. The fatty acid profile of longissimus lumborum and loin subcutaneous fat were determined. Data were analyzed by analysis of variance. Protein conversion index resulted lower in the restricted group, while backfat was slightly greater. Meat quality traits were not affected by feeding management. Slightly modifications in subcutaneous outer layer fatty acids profile were observed. The protein restriction during growing did not seem a suitable mode of feeding management for Cinta Senese pigs.

Identification and Functional Prediction of Long Intergenic Non-coding RNAs Related to Subcutaneous Adipose Development in Pigs.

An increasing number of studies have shown that long intergenic non-coding RNAs (lincRNAs) are a very important class of non-coding RNAs that plays a vital role in many biological processes. Adipose tissue is an important place for storing energy, but few studies on lincRNAs were related to pig subcutaneous fat development. Here, we used published RNA-seq data from subcutaneous adipose tissue of Italian Large White pigs and identified 252 putative lincRNAs, wherein 34 were unannotated. These lincRNAs had relatively shorter length, lower number of exons, and lower expression level compared with protein-coding transcripts. Gene ontology and pathway analysis indicated that the adjacent genes of lincRNAs were involved in lipid metabolism. In addition, differentially expressed lincRNAs (DELs) between low and high backfat thickness pigs were identified. Through the detection of quantitative trait locus (QTL), DELs were mainly located in QTLs related to adipose development. Based on the expression correlation of DEL genes and their differentially expressed potential target genes, we constructed a co-expression network and a potential pathway of DEL’s effect on lipid metabolism. Our study identified and analyzed lincRNAs in subcutaneous adipose tissue, and results suggested that lincRNAs may be involved in the regulation of subcutaneous fat development. Our findings provided new insights into the biological function of porcine lincRNAs.

Comparing pig breeds with genetically low and high backfat thickness: differences in expression of adiponectin, its receptor, and blood metabolites

Here we characterized gene expressions in subcutaneous adipose tissue and blood metabolites of pigs with genetically low backfat (Landrace) and high backfat (Meishan). As pigs aged from 1 wk-to 3-mo old, mRNA levels of adipose-specific genes increased, although their gene expressions coding for major enzymes involved in lipid metabolism (lipoprotein lipase, fatty acid synthase, and hormone-sensitive lipase) did not differ between lean and fat pigs. Instead, there were significant effects for adiponectin and its receptor AdipoR1 mRNA levels between the two breeds of which respective expressions were lower and higher in Meishan by 3 mo of age. Contrary to changes in gene expressions, the concentrations of blood glucose, triglyceride (TG), and NEFA in both breeds decreased during growth, and 3-mo-old Meishan evidenced lower glucose with higher TG than the Landrace. The homeostasis model assessment insulin resistance (HOMA-IR) index was also calculated from the measurements of fasting glucose and insulin concentration, and Meishan showed a higher value than the Landrace. We next examined these differences in Landrace and Meishan crossbreds, which were phenotypically distinguishable by the backfat thickness as the former lean type and the latter fat type. As with the purebreds, high backfat Meishan crosses showed the characteristics of lower glucose and higher TG in circulating levels and also lower adiponectin transcripts in subcutaneous adipose tissue. Collectively, our results demonstrate that levels of adiponectin and its receptor gene expressions, blood glucose, blood lipids, and HOMA-IR in pigs vary between lean and fat. These observations strongly suggest the possibility that overall metabolic differences rather than adipocyte ability itself contribute to the fatness of genetically high backfat pigs.

Additional feeding during late gestation improves initial litter weight of lactating sows exposed to high ambient temperature

ABSTRACT The present study investigated the impacts of additional feeding (AF; containing 16% excess feed than control diet in the last two weeks of gestation) during late gestation period and different backfat thickness (BFT) including low (<20 mm) and high (≥20 mm) backfat on reproductive performance, litter size, blood metabolites, hormonal profiles, colostrum, and milk composition of sows from day 90 of gestation to farrowing, and from farrowing to weaning during summer (average 28.3 °C). Fifty-four crossbred sows (Yorkshire × [...]

Factors affecting estrus and ovulation time in weaned sows with induced ovulation by GnRH administration in different seasons.

Follicle development in post-weaning sows is influenced by various factors. To control ovulation time using hormone, factors that influence ovulation should be investigated. The present study was performed to evaluate the effect of GnRH (buserelin) administration in relation to season and sow parameters on ovulation time in weaned sows. Seventy-seven weaned sows were divided into the following groups: control (hot season, n=21; cool season, n=16) and treatment (hot season, n=22; cool season, n=18). Sows were kept in a close house equipped with an evaporative cooling system. Ovulation time was determined every 6 hr using transrectal ultrasonography. Administration of 10 µg buserelin at 72 hr after weaning affected estrus-to-ovulation interval (EOI) and weaning-to-ovulation interval (WOI) in sows (P<0.05). The percentage of sows that ovulated between 44–56 hr after injection was higher in the cool season than in hot season (P<0.05). Weaning-to-estrus interval (WEI) and injection-to-estrus interval (IEI) were affected by season (P<0.05). Body condition score (BCS) of sows influenced EOI (P<0.01). Sows with low backfat thickness, lactation length <20 days, or litter weight ≥67 kg, had delayed injection-to-ovulation interval (P<0.05). In conclusions, buserelin administration (10 µg, at 72 hr after weaning) advanced ovulation. Hot season prolonged ovulation time. Sows that were weaned with lactation length of at least 20 days, litter weight less than 67 kg, or BCS of at least 3, had better responses to buserelin injection. High backfat reserve after weaning is important for ovulation induction response by buserelin injection.

PSVI-29 Increased N6-methyladenosine in LBW placentas from sows with high backfat thickness is negatively associated with FTO.

Maternal obesity is associated with low birth weight (LBW), especially in the domestic animals, such as pigs. However, the underlying mechanism how the LBW occurs in the obese pregnancy has not been well clarified.This study was to determine the role of N6-methyladenosine (m6A) modifications in LBW placenta in maternal obesity.1090 multiparous sows were divided into three groups (Low group: backfat thickness ≤17mm, Medium group: backfat thickness 18-20mm, High group: backfat thickness ≥21mm) to analyze the percentage of LBW piglets. 56, 38, and 56 placentas were collected from sows of each group respectively for the further research. Compared with the other two groups, the sows with high backfat thickness increased the percentage of piglets with birth weight ≤0.9kg and ≤1.0kg significantly. In LBW placentas from a high group, the expression of key genes related to placental angiogenesis, PPARγ and VEGFA showed a remarkable decrease, as well as lower vascularity density. Intriguingly, we for the first time reported that m6A modification was significantly increased in LBW placentas from a high group.The expressions of the demethylase, FTO were decreased at mRNA level as well as the protein level. The specific m6A methylations modified in the PPARγ and VEGFA were enhanced in LBW placentas from the high group. We deduce that the m6A modifications modulated by FTO in the key genes may regulate the placental development, resulting in the LBW.

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.

Maternal obesity aggravates the abnormality of porcine placenta by increasing N6-methyladenosine.

The growing prevalence of overweight or obese pregnancies shows an increasing risk for aberrant fetal growth and postnatal complications. Maternal obesity is associated with low birth weight (LBW) of piglets. However, the development of LBW from maternal obesity is not well understood. This study attempts to investigate the novel RNA modification N6-methyladenosine (m6A) in the placenta tissues by using sows with high backfat thickness as a model for obese pregnancy. Forty four placentas from eight sows (backfat thickness ≥21 mm) were divided into four groups by piglet weight, with group1 being LBW group (<1.0 kg), group2 (1.0-1.4 kg), group3 (1.4-1.6 kg), and group4 (>1.6 kg) as the comparative groups of normal birth weight. QPCR was used to measure the mRNA levels of the genes and western blot was used to test the content of proteins. At the same time, LC-MS/MS method was built to test the content of m6A modification in the placental RNA, and finally MeRIP-QPCR technology was employed to check the specific m6A modification in the key genes. Compared with the comparative groups, the expression levels of PPARγ, VEGFA, ABHD5, and GPR120 in both mRNA and protein decreased noticeably in the LBW group. It was also observed that the density of the H&E stained vessels became attenuated in LBW group. Importantly, for the first time, the increased m6A levels were found in LBW placentas. Lower protein level of FTO (the key demethylase of m6A) was observed in LBW placentas, whereas no difference was found among the four groups in the expression levels of METTL3, the main methyltransferase of m6A. By using MeRIP-QPCR technology, the m6A modification in PPARγ, VEGFA, ABHD5, and GPR120, as well as FTO, was considerably enhanced in the placentas from LBW group. We infer that in maternity obesity, the higher m6A modification displayed in the genes related to placental development, lipid metabolism and angiogenesis may result in the down regulation of these genes, which could be associated with m6A demethylase FTO.

Investigation of carryover effect of prior fibre consumption on growth, serum and tissue metabolic markers in Ossabaw pigs fed a high-fat diet.

Carryover effect of prior fibre consumption on metabolic markers was investigated. Treatments were arranged in 2×2 factorial with 2 fibre sources, 4% inulin or cellulose (Solka-Floc®) and fat levels (5 or 15%) for the low-fat diet (LFD) and high-fat diet (HFD) respectively. Pigs were fed the two fibre diets for the first 56d (nursery phase), and thereafter fed either the LFD or HFD containing no added fibre source from d56 to 140 (growing phase). Pigs on the HFD were heavier (p=.05) than those on LF (64.61 vs. 68.38kg), regardless of prior fibre type consumed. Pigs that were fed cellulose during the nursery and later fed the HFD had the highest ADG (p<.05). Feeding the HFD resulted in higher back fat (BF) (13.41 and 18.18±0.12mm for LFD and HFD, respectively; p<.01). The HFD resulted in higher (p<.01) insulin (0.014 and 0.016±0.001mg/L for LF and HF respectively) and glucose (100.89 and 125.03±4.39mg/dl for LF and HF respectively) concentrations in the serum. Inulin increased (p≤.02) jejunal expression of SREBP-1c and CL-4, but reduced (p<.05) TNFɑ and IL-6 expression in the ileum. Alpha-diversity was significantly different (p<.05) between the inulin and cellulose fed pigs at the end of the nursery and finishing phases. Therefore, inulin feeding before a HFD may lead to reduction in ADG and inflammatory markers in the small intestine of pigs, and thus prevent future metabolic disorders.