It has been suggested that gut microbiota play a critical role in maternal metabolic oxidative stress responses and offspring growth. However, whether the gut microbiota and oxidative stress status ...of the sows affect the litter performance during lactation is unclear. A total of 66 Yorkshire sows were identified as high (H) or low (L) litter performance sows based on litter weight at day 21 of lactation. Ten sows per group with similar parity, backfat thickness, and litter weight after cross-foster from the H or L group were collected randomly to analyze the oxidative stress and gut microbiota during lactation. The result showed that the serum total antioxidant capacity was higher in the H group, while 8-hydroxy-deoxyguanosine and thiobarbituric acid reactive substances were lower in the H group at farrowing. Four distinct clusters of bacteria were related to litter performance and reproductive periods of sows. Twelve differentially abundant taxa during gestation and 13 taxa during lactation were identified as potential biomarkers between the H group and the L group. Moreover, the litter performance and the antioxidant capacity of sows were positively correlated with
but negatively with
and
. In conclusion, this study found that gut microbiota and oxidative stress were significantly correlated with the litter performance of sows during lactation.
The objective of this study was to determine the effects of dietary crude protein (CP) levels on intestinal antioxidant status, tight junction proteins expression, and amino acids transporters levels ...in squabs. A total of 180 pairs of White King parent pigeons approximately 10 mo old were randomly assigned to 5 groups with 6 replications of 6 pairs of parental pigeons each, and were fed with 14, 15, 16, 17, and 18% CP diets for 46 d, respectively. Dietary increasing CP levels increased final body weight (linear and quadratic, P < 0.05), serum urea nitrogen (linear, P<0.05) and triglyceride levels (quadratic, P < 0.05), and reduced kidney relative weight (quadratic, P < 0.05) in squabs. Final body weight of squabs in the 18% CP diet group was higher than that of the 14, 15, and 16% CP diet groups (P < 0.05) but was similar to that of the 17% CP diet group (P > 0.05). Increasing dietary CP levels reduced intestinal malondialdehyde contents (linear and quadratic, P < 0.05) and jejunal total superoxide dismutase (T-SOD) activity (linear, P < 0.05), and enhanced (linear and quadratic, P<0.05) ileal catalase and T-SOD activities in squabs, and these effects were more prominent in the 17% CP diet group. Graded CP levels up-regulated the mRNA expression of intestinal zonula occludens 1 (linear, P < 0.05), solute carrier family 7 members 9 (linear, P < 0.05) and claudin 1 (CLDN1, linear and quadratic, P < 0.05), ileal CLDN3 and solute carrier family 6 members 14 (linear, P < 0.05) but lowered jejunal solute carrier family 6 member 14 (quadratic, P<0.05) mRNA expression in squabs. The effects of dietary CP levels on intestinal tight junction proteins expression were more apparent when its supplemental levels were 18%. These results suggested that increasing parental dietary CP levels ranged from 14 to 18% during breeding period improved growth and intestinal function of squabs, with its recommended level being 17%.
Sow milk contains necessary nutrients for piglets; however, the relationship between the levels of metabolites in sow milk and lactation performance has not been thoroughly elucidated to date. In ...this study, we analysed the metabolites in sow milk from Yorkshire sows with high lactation (HL) or low lactation (LL) performance; these categories were assigned based on the weight gain of piglets during the entire lactation period (D1 to D21). The concentration of milk fat in the colostrum tended to be higher in the HL group (P = 0.05), the level of mannitol was significantly lower in the HL group (P < 0.05) and the level of glucuronic acid lactone was significantly higher in the HL group (P < 0.05) compared to those in LL group. In mature milk, the levels of lactose, creatine, glutamine, glutamate, 4-hydroxyproline, alanine, asparagine, and glycine were significantly higher (P < 0.05) in the HL group than those in LL group. The level of fatty acids showed no significant difference between the two groups in both the colostrum and mature milk. This study suggested that lactation performance may be associated with the levels of lactose and several amino acids in sow milk, and these results can be used to develop new feed additives to improve lactation performance in sows.
Due to their beneficial effects on human health, antioxidant peptides have attracted much attention from researchers. However, the structure-activity relationships of antioxidant peptides have not ...been fully understood. In this paper, quantitative structure-activity relationships (QSAR) models were built on two datasets, i.e., the ferric thiocyanate (FTC) dataset and ferric-reducing antioxidant power (FRAP) dataset, containing 214 and 172 unique antioxidant tripeptides, respectively. Sixteen amino acid descriptors were used and model population analysis (MPA) was then applied to improve the QSAR models for better prediction performance. The results showed that, by applying MPA, the cross-validated coefficient of determination (Q²) was increased from 0.6170 to 0.7471 for the FTC dataset and from 0.4878 to 0.6088 for the FRAP dataset, respectively. These findings indicate that the integration of different amino acid descriptors provide additional information for model building and MPA can efficiently extract the information for better prediction performance.
Multi-suckling systems aim to improve animal welfare, but in these systems, a large variation is seen in piglet growth rate. Birthweight (BiW) plays an important role in explaining the variation in ...body weight (BW) gain of piglets. This study aims to investigate the relationships between BiW and piglet traits up to day 44 postpartum (p.p.). A total of 55 sows were used. The growth rate and mortality were assessed for all piglets. Feed and milk intake, behaviours, and skin lesions were assessed in four focal piglets per litter. Focal piglets were divided into four groups based on their BiW class (high BiW (HBiW) vs. low BiW (LBiW)) and growth rate class (fast vs. slow). Results showed that increased mortality was observed in piglets with a BiW below 1.1 kg. Birthweight was positively related with the number of sucklings (β = 2.8 no./kg of BiW per 7.5 h), corresponding to milk intake (β = 102 g/kg of BiW per day), and to a lesser extent, to the intake of sow feed (β = 44 g/kg of BiW per day) in week 6. Birthweight was positively related with the number of skin lesions (β = 4.3 no./kg of BiW) in week 4. We found no indications that fast-growing LBiW piglets differed from fast-growing HBiW piglets, however, fast-growing piglets of both HBiW and LBiW tended to eat more feed (485 ± 18 vs. 420 ± 17 g/day,
= 0.068), were present less often at teats of alien sows (1.1 ± 0.2 vs. 1.8 ± 0.3,
= 0.010), and had more skin lesions (9.0 ± 0.6 vs. 7.4 ± 0.4,
= 0.047), compared to slow growing piglets. Our study, thus, provides little insight into the traits that affect catchup growth in a multi-suckling environment but increases insight into the differences between fast-growing and slow-growing piglets, regardless of their birthweight class.
As a new energy‐supply service solution to address massive, distributed energy access to the power system, a virtual power plant has higher transmission reliability and real‐time communication ...requirements. To achieve collaborative optimisation, distributed load and energy resources must be aggregated using new information and communication technology. This study analyses underlying communication technologies for virtual power plant interaction from the perspective of standardisation, efficiency, reliability, and security, summarises the application of blockchain, cloud‐edge collaboration, machine learning, and other new information and communication technologies in virtual power plant energy trading, interaction, and scheduling, and proposes ideas for addressing shortcomings in interaction. To improve virtual power plant interaction, performance parameter mapping between communication and business technology, and multilevel virtual power plant interaction technology are proposed.
•The failure modes and causes of NOS525 hot forging die were clarified.•A coupled hardness-temperature-structure simulation heat treatment model was constructed by JMatPro and Deform software.•The ...life extension measures of the die were put forward.•The heat treatment process of NOS525 material was optimized.
A NOS525 steel rotary flat binaural hot forging die frequently failed too early due to collapse and wear in service. In this paper, the rotating planar binaural failure die was taken as the research object. Firstly, the sample design and sample processing of the failure die with different depths and directions were carried out. The material composition, hardness and metallographic structure of the samples were analyzed, and the tensile and impact properties were tested by direct-reading spectrometer, Rockwell hardness tester, optical microscope, scanning electron microscope, MTS testing machine and impact testing machine, etc. Meanwhile, with the help of Deform-HT software and JMatPro software, the coupling simulation of hardness, temperature and structure of the heat treatment of NOS525 steel was realized, and the hardness change of the material after heat treatment was predicted and verified by heat treatment test. The research results show that the composition of the die material is abnormal, especially the excessive P and C elements, at the same time, there is a phenomenon of quenching overheating and insufficient tempering, resulting in insufficient strength, toughness and hardness of the die material, in addition, the die surface is subjected to the cold and hot alternating load, and finally, the die surface collapses and wear too soon, resulting in its failure. Through the combination of heat treatment simulation optimization and test, the optimal heat treatment temperature of NOS525 steel was finally determined, that is, the quenching temperature of 1090℃, the first tempering temperature of 560℃, the second tempering temperature of 600℃, the third tempering temperature of 600℃, so that the mechanical properties of the material have been significantly improved.
•The failure modes and causes of Cr12Mo1V1 crimping die were clarified.•The life extension measures of the dies were put forward.•The simulation model of multi-body contact deformation is constructed ...by Deform software.•The structure designs of the electrical connector dies were optimized.
A type of Cr12Mo1V1 electric connection die occured brittle fracture after 200 times of service, and its life was much lower than the design life of the die. In this paper, the 5M1E failure analysis method was adopted, combined with the characteristics of Cr12Mo1V1 cold-work die steel, scanning electron microscopy, direct reading spectrometer, Rockwell hardness tester, metallographic microscope and other means were used to analyze and test the macro fracture morphology, material composition, mechanical properties and microstructure of Cr12Mo1V1 electric connection die. The crimping process of the die was simulated by Deform software. The results show that the material composition is not up to standard, the strength is too low, the internal eutectic carbide is not uniform, the size of carbide exceeds the standard and so on are the root causes of the short life and brittle fracture of the die. In addition, the unreasonable designs of the crack slot and round hole of the die lead to excessive stress concentration in the crimping process of the die, which is too the main reason for the brittle fracture failure of the die. In view of the above factors, the paper puts forward some measures to prolong the life of the electric connection die from the aspects of raw materials, heat treatment, forging process and die structure design.
Taking Shanghai as a case study, this study (i) examines the revival of "hanfu", namely, China's historical national costume, and the state of activities regarding people who wear it and (ii) ...clarifies how spaces in which activities of hanfu wearers take place ("activity spaces" hereafter) are considered.Full-scale activities to revive hanfu began in 2003. Consequently, in some aspects, the formal design of hanfu and the manner of wearing it are unknown. As a result, while some of the surveyed hanfu wearers pursue the "authentic" way of wearing it, many of them are young people who have a short history of wearing hanfu, and many of them tolerate freedom in ways of dressing in hanfu and freer arrangements that do not adhere to traditional formality and etiquette. As for wearing hanfu, while reaching the dual goals of pursuing "authenticity" as a historical costume and "popularizing" ethnic costumes becomes a challenge, the subjects of this study, namely, hanfu wearers, expressed differences in awareness regarding the design of the hanfu they wear and the way they wear it.The characteristics of hanfu as a recently revived national costume are also reflected in the way the wearers select their activity spaces. In other words, hanfu wearers tend to select historical sightseeing spots and similar places as activity spaces because, in such places, people are less likely to give them peculiar looks and it is considered appropriate to wear hanfu. From analysis of such activity spaces, it can be said that while the space for activities is restricted and the hanfu wearers mainly wear hanfu in historical sightseeing spots, the presence of hanfu wearers may play a role in creating the historical image of sightseeing spots and thereby attracting tourists.
In recent years, integral group housing systems, or multi-suckling (MS) systems for lactating sows and their litters have been developed, mimicking the natural living conditions of pigs, as a ...solution to welfare problems of conventional farrowing pens. However, one problem associated with these MS systems is a large variation in growth rate of piglets, a problem that is hampering the introduction of such systems in commercial practice. The main aim of this thesis was to study causes of variation in growth rate of piglets in the MS system during lactation and possibilities to reduce this variation.For effectively designing strategies to reduce growth rate variation, it is crucial to understand the underlying factors that cause this variation. In Chapter 1, potential factors which affect variation in growth rate of piglets in MS systems are discussed, focusing on piglet related characteristics, such as birthweight (BiW), intake of milk and feed, intake associated behaviours and other behaviours.As feed intake of piglets are crucial for the variation in growth rate of piglets, Chapter 2 explored the use of a novel method, the ‘dual alkane method’ to estimate individual feed intake of piglets. In this study, twelve 6.5-week-old individually housed male pigs were offered a diet containing chromium chloride (CrCl3) and the alkane hexatriacontane (C36) as in-feed markers. For three days in a row either once (R1), three times (R3) or five times (R5) daily the piglets orally received a reference marker, either ytterbium chloride (YbCl3) or the alkane dotriacontane (C32). Faecal collections, both total and spot samples were taken on days 2-4. Individually measured feed intake was recorded daily, and was compared to predicted feed intake using the ratio of the dual marker pairs (Yb:Cr and C32:C36). Based on the obtained prediction errors for feed intake with the different procedures, it was recommended to dose the alkane reference marker three times per day for 2 days (days 1-2) and analyse pooled faecal spot samples collected on days 3 and 4. This technique was subsequently used to estimate intake of piglet feed, sow feed and thereby milk intake in two experiments in the MS system (Chapter 3 and 4). The MS system at Pig Innovation Center Sterksel housed 5 sows and their piglets, during a 9 week (Chapter 3) or 7 week (Chapter 4) lactation. The sows could move freely in the system, except for days 0-3 postpartum (p.p.) after farrowing, when they were restricted in individual farrowing pens. Litters were allowed to enter the MS area, i.e., grouping of litters, on days 8-9 p.p. or on days 13-14 p.p. (see Chapter 4). Subsequently, to allow gradual weaning, intermittent suckling (IS) was applied, i.e. forcedly separating sows from piglets for several hours/day from day 28 p.p., and allowing sows to voluntarily leave the MS area from day 35 p.p. until weaning. Piglet weight was assessed for all piglets at different timepoints, but other piglet characteristics were assessed for 4 piglets, the focal piglets, in each litter. These were the piglets with the second lowest (LBW) and second highest (HBW) birthweight from both sexes.
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