Potential risk factors related to pig body weight variability from birth to slaughter in commercial conditions

Effects of increasing dietary arginine supply during the three first weeks after weaning on pig growth performance, plasma amino acid concentrations, and health status

A total of 425 weaned pigs (Exp. 1: 225 pigs [5.8 ± 0.9 kg]; Exp. 2: 200 pigs [6.1 ± 1.2 kg]) were used to determine the optimal dietary standardized ileal digestible (SID) arginine (Arg) level in early nursery diets based on growth and health responses. The basal diet in Exp.1 was formulated to meet SID Arg recommendation (0.66%; NRC, 2012) and in Exp. 2, SID Arg was set to simulate current industry practices for feeding nursery pigs (1.15 %). Basal diets were supplemented with 0.3%, 0.6%, 0.9%, and 1.2% of l-arginine to provide five levels of dietary SID Arg. Experimental diets were fed during phases I (days 0 to 7) and II (days 8 to 21) with common diets until market. Feed disappearance and body weight (BW) were measured on days 7, 14, 21, and 43. Final BW was recorded at first removal of pigs for market. Pen fecal score was assigned daily from days 0 to 21. Plasma immunoglobulin A (IgA) was determined on days 0, 7, and 14 and amino acids (AAs) concentration and plasma urea nitrogen (PUN) on days 0 and 14. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of dietary Arg. Optimal SID Arg was determined by fitting the data with piecewise regression, using growth performance as the primary response variable. In Exp. 1, dietary Arg linearly increased (P < 0.1) BW, average daily gain (ADG), and gain to feed ratio (G:F) ratio on day 21, as well as reduced (χ2 = 0.004) the percentage of pigs that lost weight (PLW) in week 1 by 29%. Dietary Arg resulted in linear improvement (P = 0.082) of ADG for the overall nursery period and quadratic improvement (P < 0.1) of final BW at marketing. In Exp. 2, dietary Arg linearly increased (P < 0.05) ADG and average daily feed intake (ADFI) in week 1, BW and ADFI (P < 0.1) on day 14, as well as reduced (χ2 ≤ 0.001) PLW in week 1. From days 0 to 21, G:F was improved quadratically (P < 0.1). Dietary Arg linearly increased (P < 0.1) ADG and BW on day 43. Dietary Arg supplementation decreased the incidence (χ2 < 0.05) of soft and watery feces during the first weeks after weaning and lower concentration of plasma IgA on days 7 and 14. Dietary Arg linearly and/or quadratically influenced plasma AA concentrations (P < 0.05), including an increase in Arg, Leu, Phe, Val, citrulline, ornithine, and PUN concentrations. Overall, weaned pigs exhibit optimal nursery growth performance and health when provided with dietary SID Arg ranging from 1.5% to 1.9%. This dietary range contributes to a reduction in the occurrence of fall-back pigs and improvements in final BW at marketing.

Utilizing productivity and health breeding-to-market information along with disease diagnostic data to identify pig mortality risk factors in a U.S. swine production system

Aggregated diagnostic data collected over time from swine production systems is an important data source to investigate swine productivity and health, especially when combined with records concerning the pre-weaning and post-weaning phases of production. The combination of multiple data streams collected over the lifetime of the pigs is the essence of the whole-herd epidemiological investigation. This approach is particularly valuable for investigating the multifaceted and ever-changing factors contributing to wean-to-finish (W2F) swine mortality. The objective of this study was to use a retrospective dataset ("master table") containing information on 1,742 groups of pigs marketed over time to identify the major risk factors associated with W2F mortality. The master table was built by combining historical breed-to-market performance and health data with disease diagnostic records (Dx Codes) from marketed groups of growing pigs. After building the master table, univariate analyses were conducted to screen for risk factors to be included in the initial multivariable model. After a stepwise backward model selection approach, 5 variables and 2 interactions remained in the final model. Notably, the diagnosis variable significantly associated with W2F mortality was porcine reproductive and respiratory syndrome virus (PRRSV). Closeouts with clinical signs suggestive of Salmonella spp. or Escherichia coli infection were also associated with higher W2F mortality. Source sow farm factors that remained significantly associated with W2F mortality were the sow farm PRRS status, average weaning age, and the average pre-weaning mortality. After testing for the possible interactions in the final model, two interactions were significantly associated with wean-to-finish pig mortality: (1) sow farm PRRS status and a laboratory diagnosis of PRRSV and (2) average weaning age and a laboratory diagnosis of PRRS. Closeouts originating from PRRS epidemic or PRRS negative sow farms, when diagnosed with PRRS in the growing phase, had the highest W2F mortality rates. Likewise, PRRS diagnosis in the growing phase was an important factor in mortality, regardless of the average weaning age of the closeouts. Overall, this study demonstrated the utility of a whole-herd approach when analyzing diagnostic information along with breeding-to-market productivity and health information, to measure the major risk factors associated with W2F mortality in specified time frames and pig populations.

Variability in feed intake the first days following weaning impacts gastrointestinal tract development, feeding patterns, and growth performance in nursery pigs

The present study investigated the effects of voluntary feed intake (FI) the first days after weaning on gastrointestinal development and protein fermentation the first week after weaning and growth performance and feeding patterns during the nursery phase. A total of 144 mixed-sex weaned pigs (24 ± 2 d old; 7.2 ± 0.8 kg body weight [BW]) were allocated to 12 pens with 12 pigs/pen. Each pen was equipped with an electronic feeding station for monitoring individual FI during a 40-d study. Pigs were classified based on their cumulative FI over the initial 3 d after weaning (FId1-3) being above or below their pen median FId1-3 (high = 919 ± 244 g or low = 507 ± 222 g FId1-3). Similarly, weaning BW classes (BW0; high = 7.72 ± 0.59 kg or low = 6.62 ± 0.88 kg BW) were created to study interactions with FId1-3. Two female pigs with either a high or a low FId1-3 per pen (n = 24) were selected for sampling at d6 and were used to study gastrointestinal development and fermentation products in the small intestine. Feeding patterns per day, FI, and growth performance were measured individually. Low FId1-3 pigs had lower (P < 0.05) daily FI during d0 to d8, d8 to d15, and d22 to d28, BW on d15, d22, d29, and d40, and average daily gain during d0 to d8, d22 to d29, and d29 to d40 compared to high FId1-3. High FId1-3 pigs increased (P < 0.05) the number of visits to the feeder between d1 to d13 and d31 to d35, and the time spent per visit only for d1 to d4 (P < 0.05). The daily rate of FI (g/min) was higher (P < 0.05) for High FId1-3 pigs on d6, d8, d9, and d10, and again several days later (d20 to d39). In addition, the high FId1-3 × high BW0 interaction improved daily FI during d18 to d40 compared to low FId1-3 × low BW0 class (P < 0.05). For the sampling on d6, low FId1-3 pigs had a lighter small intestine, colon, and pancreas, and reduced villi length, smaller villi surface area, and a lower number of goblet cells size in jejunum (P < 0.05), while concentrations of lactic acid, histamine, and cadaverine in small intestinal content were increased (P < 0.05). In conclusion, pigs with high FId1-3 became faster eaters with higher FI and growth rates toward the second half of the nursery, which was similar and additive for pigs with higher weaning BW. High FId1-3 was also associated with greater development of the gastrointestinal tract and a reduced protein fermentation 1-wk after weaning.

Classification of light Yorkshire pigs at different production stages using ordinary least squares and machine learning methods

Pig homogeneity and growth are major concerns for the pig industry today. Variability in pigs' size has a strong impact on profitability as uniformity plays a key role in the overall economic value of pigs produced. This research focused on statistical methods to identify pigs at risk of growth retardation at different stages of production. Data from 125 083 Yorkshire pigs at weaning (18-28 d), 59 533 pigs at the end of the nursery period (70-82 d) and 48 862 pigs at slaughter (155-170 d) were analyzed under three different cut-points (lowest 10, 20 and 30%) to characterize light animals. Records were randomly split into 2:1 training:testing sets, and each training data set was analyzed through an ordinary least squares approach and four machine learning algorithms (decision tree, random forest, and two alternative boosting approaches). A wide range of weighting functions were applied to give increased relevance to lighter pigs. Each resulting classification norm was used to classify light pigs in the testing data set. Both sensitivity and specificity were retained to construct the receiver operating characteristic curve, and the statistical performance of each analytical approach was evaluated by the area under the curve (AUC). In all production stages and cut-points, the random forest machine learning algorithm provided the highest AUC, closely followed by boosting procedures. For weaning BW (WW), factors related to birth BW and litter size accounted for more than 75% of the important prediction factors for light pigs. BW at the end of the nursery period and slaughter BW analyses revealed a similar pattern where WW and BW at the end of the nursery period accounted for more than 40 and 50% of statistical importance among the prediction factors, respectively. Machine learning algorithms are useful tools to easily evaluate the risk factors affecting the efficiency and homogeneity in swine. Since the BW at birth and weaning are key factors, sow nutrition and feeding management during gestation and lactation, along with piglet management during lactation, are identified as important influences on pig weight variability.

The effect of the proportion of Modern European ancestry on grower and sow performance of pigs in smallholder systems in Uganda

Several factors, including breed, lead to divergent performance of pigs for production and reproduction traits in different environments. A recent genomics study showed that Modern European (ME) pig breeds contribute to the ancestry of smallholder pigs in the Hoima and Kamuli districts, Uganda. These pigs were also involved in a longitudinal study with several traits recorded, including 540 body weights (WT) of 374 growing pigs, 195 records of total number of piglets born alive (TBA) of 157 sows, and 110 total number weaned (TNW) records of 94 sows. Linear mixed-effects models were used to test for the significance of environmental effects, including housing system, geographic location, and the season when the events occurred as well as animal-specific effects like age, sex, parity, and farrow-to-weaning interval. Stepwise model reduction starting from models with all main effects and pairwise interactions was applied. The final models were then expanded to include proportions of Modern European (ME) ancestry for the subset of animals genotyped, following genomic ancestry analysis based on a Porcine 50K SNP Chip. ME ancestry proportions ranged from 0.02 to 0.50 and were categorized into three classes (low/medium/high ME) based on 33.3% quantiles. The effects of ME classes on WT and TBA were not significant. ME showed a significant effect on TNW. Sows with a high proportion of ME weaned 2.4 piglets more than the low group, the medium ME group being intermediate. This study used genomic data to investigate the effects of genetic ancestry on the performance of smallholder pigs in Uganda. The proportion of Modern European ancestry did not exceed 0.50, therefore not allowing for the comparison of local versus pure "exotic" types of pigs. For the range of ancestries observed, which is the relevant one for current smallholder systems in Uganda, differences were small for the body weight of growing pigs and the number of piglets born alive, while higher proportions of ME ancestry resulted in significantly more piglets weaned. The availability of genotypes of a higher number of growing pigs would have been beneficial for drawing conclusions on the effect of ME ancestry on the growth rates of smallholder pigs in Uganda.

Serum metabolomic characterization in pigs in relation to birth weight category and neonatal nutrition

The objective of this study was to characterize developmental differences in low birth weight (LBW) and normal birth weight (NBW) piglets with or without pre-weaning nutrient restriction using serum metabolomic profile analysis. At farrowing, 112 piglets were identified as LBW (1.22 ± 0.28 kg) or NBW (1.70 ± 0.27 kg) and were randomly assigned to receive normal nutrition (NN) or restricted nutrition (RN) (6 h/day no suckling) from days 2 to 28 post farrow (n = 8 pigs/group). On day 28, piglets were weaned onto a common diet. Fasted blood samples were obtained on days 28 and 56 (n = 8 pigs/group) and were analyzed using quantitative metabolomics via a combination of direct injection mass spectrometry with a reverse-phase LC-MS/MS custom assay. Data were normalized using logarithmic transformation and auto-scaling. Partial least squares discriminant analysis (PLS-DA) was carried out to further explore the differential metabolites among the groups (metaboanalyst.ca) with an integrated enrichment and pathway topography analysis. On day 28, LBW piglets had lower levels of essential amino acids as well as reduced metabolites associated with fatty acid oxidation, glycolysis, and the tri-carboxylic acid (TCA) cycle compared to the NBW group. The overall reduction of metabolites associated with energy production and regulation suggests that LBW vs. NBW are in an energy-survival state. On day 56, LBW pigs had increased utilization of fatty acids and resultant ketone production, evident by increased carnitines, acetoacetate, β-hydroxybutyrate, and glycerol compared to NBW pigs. In addition, compared to the NBW pigs LBW pigs had a consistent decrease in serum glucose and lactate as well as reduced TCA cycle metabolites: pyruvate, succinate, citrate, and α-ketoglutaric acid similar to day 28. Low reliance on glycolysis and the TCA cycle and higher glycerol production in the LBW pigs may indicate impairments in glucose tolerance at 56 d. In summary, LBW piglets appear to have more metabolic alterations in early life, which is not resolved with adequate nutrition or refeeding and may elucidate physiological and metabolic mechanisms of poor growth and life performance compared to NBW pigs later in life.

Influence of dietary n-3 long-chain fatty acids on microbial diversity and composition of sows' feces, colostrum, milk, and suckling piglets' feces

Introduction

Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces.

Methods

Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning.

Results and Discussion

n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

The effect of the ryanodine receptor gene on the reproductive traits of Welsh sows

The reproductive performance of sows largely determines the efficiency of the entire pig farming industry. The purpose of our work is the evaluation of polymorphism of the ryanodine receptor gene and its impact on the reproductive traits of sows of the Welsh breed of pigs. For this study, 148 pigs of the Welsh breed were used. The reproductive traits of sows were evaluated in two adjacent generations. We conducted a comprehensive assessment of the reproductive ability of sows using the SIRQS (selection index of reproductive qualities of sows), determined phenotypic consolidation coefficients and assessed the genetic potential of the animals’ productivity. The polymorphism of the RYR1 gene was determined using polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). Data processing was performed using single-factor analysis of variance (ANOVA). Polymorphism of the ryanodine receptor gene in sows of the Welsh pig breed was evaluated. 8.0% of the animals were identified as carriers of the mutant allele of the RYR1 gene. However, no homozygous RYR1-nn animals were found. Pigs of the maternal generation carrying the homozygous NN genotype had better reproductive performance in all indicators. Sows that were carriers of the mutant allele were characterized by lower values of the genetic productivity potential compared with the entire estimated population for all productive traits. Sows which were free of the mutant allele of the RYR1 gene were characterized by large values of the SIRQS index. The values of the coefficients of phenotypic consolidation of the number of live born piglets in sows without the mutant allele were lower than in sows with the mutant allele n. Better performance of sows free of the mutant allele of the RYR1 gene was established over sows carrying it in all evaluated traits of reproductive capacity (for different traits P ranged from 0.021 to 1.0*10–4), except for number of piglets born alive per sow in the daughter generation. Sows with the NN genotype had better selection index values by 15.7% in the maternal generation and by 10.2% in the daughter generation. In order to increase the reproductive ability of sows in the studied population of Welsh pigs and achieve similar results in other herds of this breed, animals free from the mutant allele of the RYR1 gene should be selected for further reproduction in the process of breeding, while on the contrary, carriers of this gene should be gradually eliminated from the herd. To carry out breeding work, further research is needed on the entire population of Welsh pigs for the RYR1 gene.

Fecal Microbiota and Hair Glucocorticoid Concentration Show Associations with Growth during Early Life in a Pig Model

Identifying characteristics associated with fast or slow growth during early life in a pig model will help in the design of nutritional strategies or recommendations during infancy. The aim of this study was to identify if a differential growth during lactation and/or the nursery period may be associated with fecal microbiota composition and fermentation capacity, as well as to leave a print of glucocorticoid biomarkers in the hair. Seventy-five commercial male and female pigs showing extreme growth in the lactation and nursery periods were selected, creating four groups (First, lactation growth, d0−d21; second, nursery growth, d21−d62): Slow_Slow, Slow_Fast, Fast_Slow, and Fast_Fast. At d63 of life, hair and fecal samples were collected. Fast-growing pigs during nursery had higher cortisone concentrations in the hair (p < 0.05) and a tendency to have a lower cortisol-to-cortisone ratio (p = 0.061). Both lactation and nursery growth conditioned the fecal microbiota structure (p < 0.05). Additionally, fast-growing pigs during nursery had higher evenness (p < 0.05). Lactation growth influenced the relative abundance of eight bacterial genera, while nursery growth affected only two bacterial genera (p < 0.05). The fecal butyrate concentration was higher with fast growth in lactation and/or nursery (p < 0.05), suggesting it has an important role in growth, while total SCFA and acetate were related to lactation growth (p < 0.05). In conclusion, piglets’ growth during nursery and, especially, the lactation period was associated with changes in their microbiota composition and fermentation capacity, evidencing the critical role of early colonization on the establishment of the adult microbiota. Additionally, cortisol conversion to cortisone was increased in animals with fast growth, but further research is necessary to determine its implications.

Characteristics of thermal images of the mammary gland and of performance in sows differing in health status and parity

Precision livestock farming can combine sensors and complex data to provide a simple score of meaningful productivity, pig welfare, and farm sustainability, which are the main drivers of modern pig production. Examples include using infrared thermography to monitor the temperature of sows to detect the early stages of the disease. To take account of these drivers, we assigned 697 hybrid (BHZP db. Viktoria) sows to four parity groups. In addition, by pooling clinical findings from every sow and their piglets, sows were classified into three groups for the annotation: healthy, clinically suspicious, and diseased. Besides, the udder was thermographed, and performance data were documented. Results showed that the piglets of diseased sows with eighth or higher parity had the lowest daily weight gain [healthy; 192 g ± 31.2, clinically suspicious; 191 g ± 31.3, diseased; 148 g ± 50.3 (p < 0.05)] and the highest number of stillborn piglets (healthy; 2.2 ± 2.39, clinically suspicious; 2.0 ± 1.62, diseased; 3.91 ± 4.93). Moreover, all diseased sows showed higher maximal skin temperatures by infrared thermography of the udder (p < 0.05). Thus, thermography coupled with Artificial Intelligence (AI) systems can help identify and orient the diagnosis of symptomatic animals to prompt adequate reaction at the earliest time.

Comparison of effects of a single dose of MHYOSPHERE® PCV ID with three commercial porcine vaccine associations against Mycoplasma hyopneumoniae (Mhyo) and porcine circovirus type 2 (PCV2) on piglet growth during the nursery period under field conditions

Pigs routinely undergo stressful vaccination procedures, which are often unavoidable given the unavailability of safer alternatives, challenging animal welfare. The available vaccines for Mycoplasma hyopneumoniae (Mhyo) or Porcine circovirus type 2 (PCV2) are mostly administered intramuscularly in association to prevent Porcine respiratory disease complex (PRDC). MHYOSPHERE® PCV ID is the first vaccine protecting from both agents by intradermal route. This randomized, blind-field trial aimed to compare the effects of MHYOSPHERE® PCV ID with those of three different intramuscular associations of commercially available vaccines. A total of 7072 21-day-old piglets from 12 consecutive batches in one farm were randomly vaccinated with MHYOSPHERE® PCV ID (G1) or Ingelvac CircoFLEX® + Hyogen® (G2), Porcilis® PCV + M + PAC® (G3), and Porcilis® PCV + Hyogen® (G4). Growth performance during the nursery period and adverse reactions (ARs) after vaccine administration were monitored. Average Daily Weight Gain (ADWG) during the first 7 days post-weaning in G1 was 10.92, 3.03, and 20.08 g/day higher than in G2, G3, and G4, respectively, and 0.65, 4.06, and 9.58 g/day higher than in G2, G3, and G4 during the entire nursery period, respectively. G1 ADWG was significantly higher than G4 during both periods and significantly higher than G2 during the first 7 days post-weaning. Incidence of systemic ARs in G2 and G4 was 0.03% and 0.32%, respectively; none were recorded in G1 and G3. Replacing the usual intramuscular vaccination with MHYOSPHERE® PCV ID results in higher growth performance during the first weeks after weaning with no systemic ARs.

Limiting Dietary Lysine Increases Body Weight Variability by Restricting Growth Potential of the Lightest Growing Pigs

Simple Summary

Finding strategies to manage variability in growing pig operations is of major importance to avoid the extra costs associated with inefficient barn usage or penalties at the processing plants when pigs are not correctly sorted. The aim of this study was to determine whether dietary amino acid density can have an impact on body weight variability in a population of growing pigs. Feeding diets with a reduced amino acid density had a negative effect because they increased body weight variability of pens composed of the smallest pigs. For instance, in those pigs, the coefficient of variation, which is used as a measure of variability, increased significantly at the end of the experiment when dietary amino acid density was reduced. It was observed that this effect was explained by a growth restriction that was more severe the lightest the pigs were at the start of the trial. Hypothesizing that posteriorly there would be no differences in growth between those restricted pigs and the normally fed ones, the differences in growth would result in around 5–10 additional days to reach marketing weight. In conclusion, severe nutritional restrictions can negatively affect growing pigs’ body weight variability.

Abstract

The goal of this experiment was to determine the implications of dietary standardized ileal digestible lysine (SID Lys:NE) on body weight variability of growing pigs grouped in three initial body weight categories (BWCAT). Animals (N = 1170) were individually weighed and classified in 3 BWCAT (Lp: 32.1 ± 2.8 kg, Mp: 27.5 ± 2.3 kg, and Sp: 23.4 ± 2.9 kg). Afterward, pens were randomly allocated to five dietary SID Lys:NE treatments (3.25 to 4.88 g/Mcal) that were fed over 47 days. Pen coefficient of variation of Sp at day 47 was linearly increased when reducing SID Lys:NE (p < 0.01), from 9.8% to 15.4% between the two extreme dietary levels. The linear effect was different in Sp compared to Lp (p < 0.05) as no effect of SID Lys:NE was reported in the latter BWCAT (p = 0.992). Further analysis showed that this effect was explained by a growth restriction that was more severe the lightest the pigs were at the start of the trial. To summarize, swine body weight variability can be negatively affected when SID Lys requirements are not fulfilled.

Health status of slaughtered animals as indicated by postmortem inspection at slaughterhouses

The study focused on the comparison of health of cattle, pigs, sheep, goats, rabbits, poultry and ostriches slaughtered in slaughterhouses in the Czech Republic based on the occurrence of findings detected during a postmortem veterinary inspection in the period from 2010 to 2019. The level of health was expressed as the so-called PA index obtained by the ratio of the number of findings to the total number of observations (15) during the pathoanatomical examination in the slaughterhouse multiplied by one hundred. Mammals (cattle, pigs, sheep and goats) generally had a higher PA index than birds (domestic chickens, turkeys, ducks, geese, ostriches), with the exception of kids and rabbits. The highest PA index was found in cows (15.13) and piglets (12.18); whereas the lowest PA index was found in broiler chickens (0.102), rabbits, and geese (both 0.14). In poultry, the PA index values were below 1, with the exception of laying hens (PA index 2.165). A higher PA index was found in a group of adult animals (the PA index ranged from 2.17 to 15.13) and groups of young animals culled from farms (the PA index ranged from 10.79 to 12.18) than in fattened animals (the PA index ranged from 0.10 to 5.32). A comprehensive overview of the health condition of slaughtered animals enables the farmers, veterinarians, transporters and slaughterhouse operators to take appropriate and precisely targeted preventive measures, thereby increasing the animal welfare and health in the future while reducing the incidence of carcass damage.

Pregnancy in pigs: the journey of an early life

Embryo mortality is responsible for greater losses in litter size in pigs. It is well known that pregnancy establishment is a complex process, and important changes occur continuously in both the corpora lutea and the endometrium, which varies depending on the pre-natal development phase: embryonic, pre-implantation or fetal stages. The placenta is a key organ responsible for the exchange of nutrients, metabolites and respiratory gases between mother and fetuses. The porcine placenta is diffuse, epitheliochorial, and placentation begins with implantation, which involves specialized cell adhesion and cell migration, leading to the attachment of the trophectoderm to the uterine endometrial lumen epithelium. The efficiency with which the placenta provides adequate amounts of nutrients and oxygen to the fetus is crucial for proper fetal growth and development. In the last decades, emphasis on selection for sow prolificacy has resulted in a substantial increase in the number of piglets born per litter, which had a direct effect on piglet quality, compromising birth weight and litter uniformity. Placental insufficiency will lead to fetal intrauterine growth restriction. This review addresses the main events of early embryo development, including preimplantation and implantation periods. In addition, placentation and its role on fetal development are covered, as well as intrauterine growth restriction, as it is a natural condition in the pig, with long lasting detrimental effects to the production chain.

High levels of standardized ileal digestible amino acids improve feed efficiency in slow-growing pigs at late grower-finisher stage

Slow-growing pigs negatively affect production efficiency in conventional pig farms by increasing the occupation time of the facilities and being a limiting factor for the All-In/All-Out swine production systems. This subset of pigs is usually managed with the rest of the pigs, and their nutrient requirements may not be fulfilled. The purpose of the present study was to compare the productive performance of slow- and fast-growing pigs to different standardized ileal digestible (SID) amino acids (AA) dietary levels at late grower-finisher stage. A total of 84 pigs were weighed, tagged, and classified as slow-growing (SG; n = 48; 24.1 ± 1.38 kg) or fast-growing pigs (FG; n = 36; 42.7 ± 1.63 kg) at 11 weeks of age. Pigs were housed in mixed sex pens (n = 8 SG+6 FG/pen) equipped with feeding stations to record daily feed intake per individual pig. Pigs were assigned to three dietary treatments resulting in a 2 × 3 factorial arrangement at 15 weeks of age. Isoenergetic diets were formulated by increasing the ideal protein profile based on the following SID lysine (Lys) levels: 0.92%, 1.18% and 1.45%. Pigs were weighed bi-weekly until 21 weeks of age. Fast-growing pigs were 33.7 kg heavier, gained 255 g/day and consumed 625.5 g/day more than SG pigs (p < 0.001). No interaction or diet effects were observed for final body weight, average daily gain and average daily feed intake (p > 0.05). However, feed conversion ratio was 0.3 lower for SG pigs fed 1.45% SID Lys/AA compared to SG pigs fed 0.92% SID Lys/AA (p = 0.002). Feed conversion ratio was not different within the FG pigs' dietary treatments (p > 0.05). The efficiency of SG pigs may be improved when dietary SID AA levels are increased from 0.92 up to 1.45% SID Lys/AA. Thus, nutrient requirements may vary depending on growth rate at the same age, and SG pigs may require higher dietary SID AA levels than FG pigs to achieve similar productive performance.

A Meta-Analysis to Understand the Relationship between Pig Body Weight and Variation from Birth to Market

Simple Summary

Understanding and managing variation in live weight within a pig population is key for swine producers to avoid economic penalties at processing plants. The objective of this meta-analysis was to determine the relationship between coefficient of variation (CV) and standard variation (SD) as a function of body weight for pigs and develop equations to predict CV and SD of a population of pigs from birth to market weight. Results reveal that there is a quadratic relationship between variation and body weight. Coefficient of variation decreases as live weight increases, but the slope is less pronounced as body weights became greater. Conversely, SD increases quadratically as body weight (BW) increases, with a less pronounced slope when BW is high within the population. Thus, the equations developed can be an effective tool for producers to predict normal BW variation within a group of pigs, which can then aid in the development of marketing strategies for finishing pigs.

Abstract

This meta-analysis aims to understand the changes in pig body weight (BW) variation from birth to market and develop prediction equations for coefficient of variation (CV) and standard deviation (SD) as a function of BW. Standard deviation is the measure of dispersion of a set of values from the mean and CV is the SD expressed as a percentage of the mean. Data collected from 16 papers and data sets yielded 117,268 individually weighed pigs with sample size ranging from 120 to 4108 pigs. Polynomial regression analysis was conducted separately for each variation measurement. The resulting prediction equations (CV (%) = 20.04 − 0.135 × (BW) + 0.00043 × (BW)², R² = 0.79; SD = 0.41 + 0.150 × (BW) − 0.00041 × (BW)², R² = 0.95) suggest that there is a quadratic decreasing relationship between the CV of a population and BW, the slope gets smaller as mean BW increases from birth to market. A quadratic increasing relationship is observed for SD, with slope being smaller as mean BW of pigs increases from birth to market. These prediction equations can be used by swine producers to estimate expected CV and SD of BW among a population of pigs.

Management and Feeding Strategies in Early Life to Increase Piglet Performance and Welfare around Weaning: A Review

The performance of piglets in nurseries may vary depending on body weight, age at weaning, management, and pathogenic load in the pig facilities. The early events in a pig's life are very important and may have long lasting consequences, since growth lag involves a significant cost to the system due to reduced market weights and increased barn occupancy. The present review evidences that there are several strategies that can be used to improve the performance and welfare of pigs at weaning. A complex set of early management and dietary strategies have been explored in sows and suckling piglets for achieving optimum and efficient growth of piglets after weaning. The management strategies studied to improve development and animal welfare include: (1) improving sow housing during gestation, (2) reducing pain during farrowing, (3) facilitating an early and sufficient colostrum intake, (4) promoting an early social interaction between litters, and (5) providing complementary feed during lactation. Dietary strategies for sows and suckling piglets aim to: (1) enhance fetal growth (arginine, folate, betaine, vitamin B12, carnitine, chromium, and zinc), (2) increase colostrum and milk production (DL-methionine, DL-2-hydroxy-4-methylthiobutanoic acid, arginine, L-carnitine, tryptophan, valine, vitamin E, and phytogenic actives), (3) modulate sows' oxidative and inflammation status (polyunsaturated fatty acids, vitamin E, selenium, phytogenic actives, and spray dried plasma), (4) allow early microbial colonization (probiotics), or (5) supply conditionally essential nutrients (nucleotides, glutamate, glutamine, threonine, and tryptophan).

Maternal Supplementation with Polyphenols and Omega-3 Fatty Acids during Pregnancy: Effects on Growth, Metabolism, and Body Composition of the Offspring

Simple Summary

The present study aimed to determine benefits and risks of a dietary supplementation combining hydroxytyrosol and n3 polyunsaturated fatty acids (PUFA) on developmental patterns and metabolic traits of offspring in swine, a model of intrauterine growth restricted (IUGR) pregnancies. There were no deleterious effects on the reproductive traits of the sows and the postnatal features of the piglets. Piglets from the supplemented sows, in spite of a lower mean weight and corpulence at birth, showed higher average daily weight gain and fractional growth rate afterwards. Consequently, they reached higher weight and corpulence with increased muscle development and better lipidemic and fatty acids profiles than control offspring at juvenile stages.

Abstract

Maternal supplementation with antioxidants and n3 PUFAs may be a promising strategy to reduce the risk of intrauterine growth restriction and preterm delivery, which may diminish the appearance of low-birth-weight neonates. The present study aimed to determine benefits and risks of a dietary supplementation combining hydroxytyrosol, a polyphenol from olive leaves and fruits, and n3 PUFAs, from linseed oil, on developmental patterns and metabolic traits of offspring in swine, a model of IUGR pregnancies. The results obtained indicate that maternal supplementation with hydroxytyrosol and n-3 fatty acids during pregnancy has no deleterious effects on the reproductive traits of the sows (prolificacy, homogeneity of the litter, and percentage of stillborns and low-birth-weight, LBW, piglets) and the postnatal features of the piglets (growth patterns, adiposity, and metabolic traits). Conversely, in spite of a lower mean weight and corpulence at birth, piglets from the supplemented sows showed higher average daily weight gain and fractional growth rate. Thus, at juvenile stages afterwards, the offspring from the treated group reached higher weight and corpulence, with increased muscle development and better lipidemic and fatty acid profiles, in spite of similar adiposity, than offspring in the control group. However, much caution and more research are still needed before practical recommendation and use in human pregnancies.

Increasing Dietary Lysine Impacts Differently Growth Performance of Growing Pigs Sorted by Body Weight

An experiment was conducted analyzing whether growing pigs classified in different initial body weight categories (BWCAT) have a different response to increasing standardized ileal digestible lysine to net energy ratio (SID Lys:NE), to assess whether light pigs might benefit from being differentially fed. A total of 1170 pigs in pens of 13 were individually weighed, classified in 3 BWCAT (Lp: 32.1 ± 2.8 kg, Mp: 27.5 ± 2.3 kg, and Sp: 23.4 ± 2.9 kg), and afterwards pens were randomly allocated to 5 dietary SID Lys:NE treatments (3.25 to 4.88 g/Mcal) fed over 47 days. Results reported a greater linear improvement of growth and feed efficiency of Sp compared to Lp when increasing SID Lys:NE. Modelling the response to SID Lys:NE using quadratic polynomial models showed that the levels to reach 98% of maximum growth from day 0-47 were 3.67, 3.88, 4.06 g SID Lys/Mcal NE for Lp, Mp, and Sp, respectively. However, due to the overlapping SID Lys:NE confidence intervals at maximum performance, it was not possible to determine if requirements were different between BWCAT. Summarizing, the results suggested that feeding small pigs greater SID Lys:NE than large pigs can improve their performance and increase the efficiency of the overall production system.

Predicting Productive Performance in Grow-Finisher Pigs Using Birth and Weaning Body Weight

This study aimed to (1) investigate the effect of birth and weaning body weight (BW) on performance indicators of grow-finisher pigs and (2) estimate birth and weaning BW cut-off values in order to identify slow growing pigs (SGP). Pigs (n = 144) were classified as SMALL (0.9 ± 0.13 kg) or BIG (1.4 ± 0.20 kg) at birth and re-classified as SMALL (5.4 ± 1.6 kg) or BIG (6.3 ± 1.91 kg) at weaning. Individual BW was recorded bi-weekly, and feed intake was recorded on a daily basis. Average daily gain (ADG) and feed intake, feed conversion ratio (FCR) and days to target slaughter weight (TSW) were calculated. SMALL-SMALL pigs had lower ADG (p < 0.05) requiring 167.1 days (i.e., 14.2 extra days) to TSW (p < 0.05) compared with BIG pigs at birth and/or weaning. However, FCR was similar between groups (p > 0.05). Pigs weaned at <3.7 kg BW would likely be SGP. Pigs born at ≥1.1 kg BW or weaned at ≥6.4 kg BW are more likely to reach TSW at 22 weeks of age. The results suggest that birth BW might not be the best predictor for subsequent performance, as some small-born pigs were able to catch up with their bigger counterparts. The cut-off values identified could be used to design specific management and nutritional strategies for SGP.

The Health and Welfare of Pigs from the Perspective of Post Mortem Findings in Slaughterhouses

The health and welfare of pigs was evaluated on the basis of the data on patho-anatomic findings obtained during the veterinary examination of pigs slaughtered in slaughterhouses in the Czech Republic in the period from 2010 to 2017. High numbers of lesions in organs found especially in lungs (finisher pigs 41%, sows 24% and piglets 52%), kidneys (finisher pigs 14%, sows 32% and piglets 15%) and liver (finisher pigs 12%, sows 18% and piglets 19 %) indicate impaired health and welfare of pigs transported for slaughter. The differences in the number of findings between finisher pigs, sows and piglets were statistically significant (p < 0.001). The character of most findings was chronic, which document health and welfare problems occurring on farms as a result of the current pig husbandry. However, acute findings were also detected and indicated processes occurring shortly before and during transport to the slaughterhouse. An important finding is the incidence of parasitic lesions in the liver in finisher pigs (finisher pigs 4%, sows 1% and piglets 1%) that documents persistent occurrence of parasitic invasions on pig farms. Findings of traumatic lesions on limbs in sows and piglets (finisher pigs 0.08%, sows 0.14% and piglets 0.15%) are far below the frequency of the findings in organs; however, their incidence should be further reduced by adjusting the technology of housing, transport and handling. In conclusion, the level of health and related welfare of pigs based on the assessment of post mortem findings in the slaughterhouses vary. Overall, the worst situation is in piglets, followed by sows and the best evaluated are finisher pigs. Post mortem inspection revealed significant numbers of patho-anatomic changes even in pigs considered fit to be transported to the slaughterhouse and slaughtered for human consumption. It is clear that there is still a considerable space for improving the level of health and welfare of the individual categories of pigs.

L-arginine supplementation during the final third of gestation improves litter uniformity and physical characteristics of neonatal piglet thermoregulation

The study assessed the effects of dietary L-arginine supplementation from days 85 to 115 of gestation on sow performance, litter quality, piglet physiology and survival variables in the first 24 hr of life. Twenty multiparous sows, with a history of hyperprolificacy (more than 14 piglets per litter), were used. A completely randomized experimental design was used, consisting of two treatments: feed supplemented or not with 1% L-arginine from days 85 to 115 of gestation. The experimental unit consisted of the sow and its respective litter, using 10 replicates per treatment. The sows were distributed into the treatments based on body condition and parity. Supplementation with L-arginine reduced the within-litter standard deviation and the within-litter coefficient of variation of piglet weight at 24 hr by 54 g and 4.14 percentage points respectively (p = .029; p = .035). Supplementation with 1.0% L-arginine decreased the percentages of piglets weighing less than 800 g by 5.60 and 5.08 points at birth and at 24 hr of life respectively. Piglets from sows supplemented with L-arginine had higher (p = .088) average rectal temperatures at birth and lower (p = .030) rectal temperature at 24 hr of life in comparison with control piglets. No significant differences in placental weight or estimated colostrum production and intake were observed in the first 24 hr of life. At 24 hr of life, piglets weighing less than 1,000 g and from supplemented sows had lower (p = .048) surface/mass ratios and higher body mass index (p = .070). Piglets from supplemented sows and who weighed 1601 to 1,800 g had lower body mass index and ponderal index (p = .002; p = .003). Supplementation with L-arginine during the final third of gestation reduces the incidence of unviable piglets (<800 g) and improved litter uniformity and piglets' body conformation within the first 24 hr of life.

Phytogenic actives supplemented in hyperprolific sows: effects on maternal transfer of phytogenic compounds, colostrum and milk features, performance and antioxidant status of sows and their offspring, and piglet intestinal gene expression

Phytogenic actives (PA) are plant-derived natural bioactive compounds that may promote livestock health and well-being, as well as improve growth performance and production efficiency. The current study aims to evaluate their effects on sows and their offspring. Eighty-one hyperprolific sows (up to parity 7) were assigned to 3 experimental treatments. Control sows were offered a nonsupplemented diet during gestation and lactation, and treated sows were fed the control diet supplemented with 1 g/kg of a blend of PA (BPA) in lactation (L) or during gestation and lactation (GL). An evaluation was made of placental and milk maternal transfer of these BPA and colostrum-milk features, sows and piglets antioxidant status, reproductive performance (litter size), body weight (BW) changes, weaning-estrus interval, and litter performance. Finally, piglet´s jejunum gene expression was measured. The BPA supplementation during gestation (GL) increased the number of piglets born alive (P = 0.020) and reduced (P < 0.05) the newborn piglets BW, while there were no differences among treatments on the suckling (day 20) and weaned (day 7) piglets BW (P > 0.05). Dietary phytogenic volatile compounds reached GL placental fluid, and milk of L and GL sows (P < 0.05). Moreover, colostrum protein in GL and milk fat content in L and GL were increased (P < 0.05). Milk of GL showed inhibitory activity against Bacillus subtilis and Staphylococcus aureus (P < 0.05). Antioxidant status of GL sows showed an enhanced (P < 0.05) of catalase (CAT) and total antioxidant capacity levels at early gestation (day 35), whereas higher levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzymes at late gestation (day 110). Likewise, GL newborn piglets showed higher CAT levels, whereas both CAT and SOD levels in suckling piglets, as well as CAT, SOD, and GSH-Px in weaned piglets, were increased in L and GL (P < 0.05). Jejunum messenger ribonucleic acid abundance of suckling piglets in L and GL groups showed overexpression of barrier function MUC2, digestive enzyme IDO, and immune response PPARGC-α, TNF-α, TGF-β1, and IL-10 genes (P < 0.05). In conclusion, dietary BPA supplementation in hyperprolific sows increased the litter size (born alive) and improved the composition and bioactivity of colostrum and milk, besides, modified the antioxidant status of sows and their offspring, as well as the suckling piglets gut health gene expression. Several BPA volatile compounds were prenatal and postnatal maternally transferred (placental fluid and milk).

Polyphenols and IUGR Pregnancies: Effects of Maternal Hydroxytyrosol Supplementation on Postnatal Growth, Metabolism and Body Composition of the Offspring

Maternal supplementation with the polyphenol hydroxytyrosol in a swine model of intrauterine growth restriction (IUGR) improves the fetal oxidative status, decreases the appearance of low birth-weight neonates and favors growth during early postnatal stages (lactation). The current study aimed to determine whether hydroxytyrosol supplementation can also improve developmental patterns, metabolic traits, and body composition of the offspring during later postnatal stages (from weaning to adulthood). A total of 21 piglets born from control untreated sows and 20 piglets born from sows treated with hydroxytyrosol during the last two-thirds of pregnancy were selected on the basis of similar body weights at weaning, for avoiding any interfering effects occurred during lactation. The pigs in the treated group had higher average daily weight gain (ADWG) and, therefore, reached higher body weight and corpulence, greater muscle development and higher adiposity than their control counterparts. The following were not found: significant effects on metabolism and body composition except changes in the muscular fatty acid composition of the treated pigs coming from the largest litters; those more affected by IUGR processes. These findings suggest that maternal supplementation with hydroxytyrosol may improve juvenile development of offspring in at-risk pregnancies and pave the way for more specific studies aiming to elucidate effects on adiposity, metabolism, and meat organoleptic characteristics.

Effects of added fat on growth performance of finishing pigs sorted by initial weight

Two studies were conducted to determine whether dietary fat fed to pigs of different weight categories differentially influences growth performance. Both experiments were conducted in a 2 × 3 factorial arrangement with main effects of dietary fat addition (0 or 6% choice white grease) and sort weight category (HEAVY, LIGHT, or MIXED). In experiment 1, 1,032 pigs (initially 30.7 kg) were individually weighed and sorted into two body weight (BW) groups with one group consisting of pigs greater than median BW and the other group less than median BW. Pens were then formed by randomly selecting pigs: 1) only from heavy group (HEAVY), 2) only from light group (LIGHT), or 3) from both heavy and light groups to create a normal distribution around barn BW mean (simulation of unsorted pigs; MIXED). In experiment 2, 1,176 pigs (initially 35.1 kg) were visually sorted into BW groups and assigned to HEAVY, LIGHT, and MIXED pen weight categories. Overall in experiment 1, adding 6% dietary fat increased average daily gain (ADG) of LIGHT pigs, but not HEAVY pigs (HEAVY vs. LIGHT × fat interaction, P = 0.03), but increased (P < 0.05) ADG regardless of sort category in experiment 2. In both experiments, HEAVY pigs had greater (P < 0.05) overall ADG and average daily feed intake (ADFI), but decreased (P < 0.05) G:F compared with LIGHT pigs. However, when HEAVY and LIGHT treatment groups were combined, growth performance and carcass characteristics were similar to MIXED pigs. Sorting decreased coefficient of variation (CV) of final BW but did not affect CV of ADG. In conclusion, because adding fat to the diets of lightweight pigs improved ADG in both experiments, dietary fat could be used selectively in the barn to increase the weight of the lightest 50% of the pigs. However, the sorting pigs into light and heavy weight groups did not improve growth performance or carcass characteristics.

Effect of live yeast Saccharomyces cerevisiae supplementation on the performance and cecum microbial profile of suckling piglets

One mechanism through which S. cerevisiae may improve the performance of pigs is by altering the composition of the gut microbiota, a response that may be enhanced by early postnatal supplementation of probiotics. To test this hypothesis, newborn piglets (16 piglets/group) were treated with either S. cerevisiae yeast (5 x 109 cfu/pig: Low) or (2.5 x 1010 cfu/piglet: High) or equivalent volume of sterile water (Control) by oral gavage every other day starting from day 1 of age until weaning (28±1 days of age). Piglet body weight was recorded on days 1, 3, 7, 10, 17, 24 and 28 and average daily gain (ADG) calculated for the total period. At weaning, piglets were euthanized to collect cecum content for microbial profiling by sequencing of the 16S rRNA gene. ADG was higher in both Low and High yeast groups than in Control group (P<0.05). Alpha diversity analyses indicated a more diverse microbiota in the Control group compared with Low yeast group; the High yeast being intermediate (P < 0.01). Similarly, Beta diversity analyses indicated differences among treatments (P = 0.03), mainly between Low yeast and Control groups (P = 0.02). The sparse Partial Least Squares Discriminant Analysis (sPLS-DA) indicated that Control group was discriminated by a higher abundance of Veillonella, Dorea, Oscillospira and Clostridium; Low yeast treated pigs by higher Blautia, Collinsella and Eubacterium; and High yeast treated pigs by higher Eubacterium, Anaerostipes, Parabacteroides, Mogibacterium and Phascolarctobacterium. Partial Least Squares (PLS) analysis showed that piglet ADG was positively correlated with genus Prevotella in High yeast group. Yeast supplementation significantly affected microbial diversity in cecal contents of suckling piglets associated with an improvement of short chain fatty acid producing bacteria in a dose-dependent manner. In conclusion, yeast treatment improved piglet performance and shaped the piglet cecum microbiota composition in a dose dependent way.