Performance and Meat Quality of Intrauterine Growth Restricted Pigs

Intrauterine growth restriction defined by increased brain-to-liver weight ratio affects postnatal growth and protein efficiency in pigs

Intrauterine growth restriction (IUGR) refers to impaired foetal growth during gestation, resulting in permanent stunting effects on the offspring. This study aimed to investigate the effects of IUGR on growth performance, body composition, blood metabolites, and meat quality of pigs from birth (n = 268) to slaughter (n = 93). IUGR piglets have prioritised brain development as a foetal adaptive reaction to placental insufficiency. This survival mechanism results in a higher brain-to-liver weight ratio (BrW/LW). One day (±1) after birth, computed tomography (CT) was performed on each piglet to assess their brain and liver weights. A threshold value of 0.78 (mean + SD) was chosen to divide the piglets into two categories - NORM (BrW/LW < 0.78) and IUGR (BrW/LW > 0.78). Moreover, each piglet was classified as either normal (score 1), mild IUGR (score 2), or severe IUGR (score 3) based on the head morphology. BW was recorded weekly, and average daily gain (ADG) was calculated for lactation, starter, grower, and finisher periods. Body composition was assessed after weaning (29.6 ± 0.7 d), at 20 kg (64 ± 7.2 d), 100 kg (165 ± 12.3 d), and on the carcasses using Dual-energy X-ray absorptiometry (DXA). Content and deposition rates of single nutrients, as well as energy and CP efficiency, were measured at 20 and 100 kg. Feed intake was recorded from 20 kg to slaughter. Meat quality was assessed on the carcasses. A total of 70% of the piglets assigned a score of 3 were NORM according to their BrW/LW. The IUGR category showed a lower ADG in the lactation (P < 0.01), starter (P = 0.07), and grower phases (P < 0.05) and a reduced CP efficiency in the grower-finisher period (P < 0.01) compared to the NORM group. IUGR pigs had a lower gain-to-feed ratio in the finisher period (P = 0.01) despite similar average daily feed intake, and they required more days (P < 0.01) to reach the slaughter weight. Additionally, their meat was darker (P = 0.01) than that of NORM pigs. The BrW/LW was inversely proportional to the ADG from birth to slaughter and negatively correlated with the CP deposition rate and efficiency in the grower-finisher period (P < 0.01). Furthermore, the higher the BrW/LW, the longer it took the pigs to reach the slaughter weight (P < 0.01). In conclusion, the identification of IUGR piglets based on the head morphology does not always agree with an increased BrW/LW. IUGR affects growth performance from birth to slaughter, CP efficiency in the grower-finisher period and meat quality.

Determining the Effect of Pancreatic-like Enzymes (PLEMs) Added to the Feed of Pregnant Sows on Fetal Size of Piglets to Minimize IUGR Syndrome Caused by Fetal Malnutrition

The present study aimed to develop a feeding strategy for pregnant sows that involved the prenatal administration of a mixture of pancreatic-like fungal enzymes, such as lipase, amylase, and protease, at (1) 1-115 days of gestation (group D1) and (2) 80-115 days of gestation (group D2) and to carry out a comparison with groups of sows that were not receiving such supplementation (negative control (NC) and positive control (PC)). It was found that the administration of the enzyme supplement resulted in a significant shortening of gestation (p ≤ 0.01). The pancreatic enzymes administered to sows had a significant effect on the number of liveborn piglets and weaned piglets, which was higher compared with the control groups that did not receive supplementation: D1-12.1 ± 1.1 and 11.12 ± 1.1 and D2-12.8 ± 1.3 and 11.75 ± 0.07 vs. the control groups KN-10.7 ± 1.0 and 9.62 ± 0.95 and KP-10.9 ± 1.2 and 10.15 ± 1.0 (p < 0.006), respectively. Significant changes in piglet growth were observed after weaning up to 70 days of age. During this period, the most favorable growth parameters were observed in groups D2 (420 ± 91 g) and PC (407 ± 103 g), in which piglets obtained a mixture of pancreatic enzymes (lipase, amylase, and protease) at 3 weeks of age, and significantly higher weight gain and feed intake were observed compared with groups NC (378 ± 114 g) and D1 (381 ± 96 g) (p ≤ 0.007). In contrast, insulin levels were significantly lower in groups D1 and D2, with values of 6.8 IU/mL and 6.7 IU/mL, respectively, compared with groups NC (14.6 IU/mL) and PC (16.6 IU/mL) (p ≤ 0.01). Piglets in group D2 had a significantly better feed conversion ratio (FCR) of 1.604 ± 0.10 compared with the other dietary groups: KN-1.986 ± 0.14; KP-1.704 ± 0.11; and D1-1.932 ± 0.15 (p ≤ 0.03). Histological imaging confirmed a significantly thicker intestinal epithelium and intestinal mesenteron in animals from groups D2 and PC (p ≤ 0.03). Animals from the groups KP, D1, and D2 receiving enzymes showed a highly significant increase in the surface area of pancreatic follicles and pancreatic surface area compared with the group without KN supplementation (p < 0.01). Furthermore, significantly higher activity of the brush border enzyme lactase was observed in groups D1, D2, and PC, with values of 32.90 ± 3.99, 30.00 ± 6.83, and 29.60 ± 29.60, respectively, compared with group NC, with a value of 21.80 ± 3.27 (p ≤ 0.01).

Technological advances in protein extraction, structure improvement and assembly, digestibility and bioavailability of plant-based foods

Plant-based foods are being considered seriously to replace traditional animal-origin foods for various reasons. It is well known that animals release large amounts of greenhouse gases into the environment during feeding, and eating animal-origin foods may also cause some health problems. Moreover, animal resources will likely be in short supply as the world population grows. It is highly likely that serious health problems ascribed to insufficient protein intake in some areas of the world will occur. Studies have shown that environmentally friendly, abundant, and customizable plant-based foods can be an effective alternative to animal-based foods. However, currently, available plant-based foods lack nutrients unique to animal-based foods. Innovative processing technologies are needed to improve the nutritional value and functionality of plant-based foods and make them acceptable to a wider range of consumers. Therefore, protein extraction technologies (e.g., high-pressure extraction, ultrasound extraction, enzyme extraction, etc.), structure improvement and assembly technologies (3D printing, micro-encapsulation, etc.), and technologies to improve digestibility and utilization of bioactive substances (microbial fermentation, physical, etc.) in the field of plant-based foods processing are reviewed. The challenges of plant-based food processing technologies are summarized. The advanced technologies aim to help the food industry solve production problems using efficient, environmentally friendly, and economical processing technologies and to guide the development of plant-based foods in the future.

Fetal and placental development in early gestation of hyper-prolific sows

Modern hyper-prolific sows produce large litters with a high within-litter variation in birth weight and an increased number of low-birth-weight piglets per litter with higher mortality rates and lower growth rates compared to heavier littermates. This study aimed to describe fetal development in hyper-prolific sows, to characterize differences between large and small fetuses, and to determine when within-litter variation in fetal weight can be detected. Forty-seven multiparous sows were blood-sampled and slaughtered at day 28, 33, 45, 50, and 56 of gestation. Number of fetuses were counted, fetal body and organ weights were measured, and the intrauterine positioning was recorded. Length, width, and area of each placenta was measured and the fetus weight/placental weight ratio was calculated. The umbilical cords of the smallest, medium and the largest fetus of each litter were sampled for histological analysis. In total measurements were obtained for 1161 fetuses. The results revealed no difference in fetal survival between the gestational days (P > 0.05). Intrauterine positioning near the cervix significantly reduced fetal weight at day 56 (P < 0.05). Total litter weight and average fetal weight increased with gestational age and individual fetal weight was negatively affected by litter size from day 33 and onwards (P < 0.05). The coefficient of variation for within-litter variation in fetal weight was higher at day 28 compared to the other gestational days (P < 0.05). Relative brain- and heart weights decreased from day 28-56 (P < 0.001). Small fetuses had relatively heavier brains and hearts at day 45, 50 and 56 (P < 0.001). Size of placenta, fetus weight/placental weight ratio and length of umbilical cord increased with gestational age (P < 0.001). There was a positive correlation between size of placenta and weight of individual fetus (P < 0.001), the weight of the fetus was positively correlated with umbilical cord length (P < 0.001) and the umbilical cross-sectional area was correlated to fetal weight at day 56 (P < 0.01). Individual fetal weight was positively correlated to the fetus weight/placental weight ratio (P < 0.001). In conclusion, fetal growth was affected by litter size, placental weight, and -area, and umbilical cord length. Lightweight fetuses were characterized by having placentas with lower weight and area and shorter umbilical cords. Lastly, within-litter variation in fetal weight was detectable at day 28, and the coefficient of variance remained stable from day 33-56.

Dietary glycine supplementation enhances postweaning growth and meat quality of pigs with intrauterine growth restriction

Pigs with intrauterine growth restriction (IUGR) have suboptimum growth performance and impaired synthesis of glycine (the most abundant amino acid in the body). Conventional corn- and soybean meal-based diets for postweaning pigs contain relatively low amounts of glycine and may not provide sufficient glycine to meet requirements for IUGR pigs. This hypothesis was tested using 52 IUGR pigs and 52 litter mates with normal birth weights (NBW). At weaning (21 d of age), IUGR or NBW pigs were assigned randomly to one of two nutritional groups: supplementation of a corn-soybean meal-based diet with either 1% glycine plus 0.19% cornstarch or 1.19% L-alanine (isonitrogenous control). Feed consumption and body weight (BW) of pigs were recorded daily and every 2 or 4 wks, respectively. All pigs had free access to their respective diets and clean drinking water. Within 1 wk after the feeding trial ended at 188 d of age, blood and other tissue samples were obtained from pigs to determine concentrations of amino acids and meat quality. Neither IUGR nor glycine supplementation affected (P > 0.05) feed intakes of pigs per kg BW. The final BW, gain:feed ratio, carcass dressing percentages, and four-lean-cuts percentages of IUGR pigs were 13.4 kg, 4.4%, 2%, and 15% lower (P < 0.05) for IUGR pigs than NBW pigs, respectively. Compared with pigs in the alanine group, dietary glycine supplementation increased (P < 0.05) final BW, gain:feed ratio, and meat a* value (a redness score) by 3.8 kg, 11%, and 10%, respectively, while reducing (P < 0.05) backfat thickness by 18%. IUGR pigs had lower (P < 0.05) concentrations of glycine in plasma (-45%), liver (-25%), jejunum (-19%), longissimus dorsi muscle (-23%), gastrocnemius muscle (-26%), kidney (-15%), and pancreas (-6%), as compared to NBW pigs. In addition, dietary glycine supplementation increased (P < 0.05) concentrations of glycine in plasma and all analyzed tissues. Thus, supplementing 1% of glycine to corn-soybean meal-based diets improves the growth performance, feed efficiency, and meat quality of IUGR pigs.

Effects of maize silage feeding on growth performance, carcass characteristics, digestive system length, chemical composition, and meat quality of domestic geese

This study aimed to explore the effects of corn silage (CS) on growth performance, carcass characteristics, digestive system length, and some meat quality traits of geese. A total of 35 19-week-old Turkish indigenous male geese with similar body weight were randomly divided into five groups with individual pens of seven geese per group and fed for 84 D. The treatments were composed of a basal diet (100% concentrate feed) without corn silage (0CS), 10% CS + 90% concentrate feed (10CS), 20% corn silage + 80% concentrate feed (20CS), 30% corn silage + 70% concentrate feed (30CS), and 40% corn silage + 60% concentrate feed (40CS). Dietary CS supplementation did not affect growth performance, dressing percentage, liver and gizzard weights, digestive system length of geese, and the organoleptic quality characteristics of meat. The 0CS and 20CS geese had a higher instrumental hardness value than other treatment geese (p < 0.05). Also, the 40CS group had the lowest hardness value (p < 0.05). Adhesiveness value was lower in the 0CS group compared to all silage treatments (p < 0.05). Gumminess value was lower in the 40CS group compared to the control group (p < 0.05). The 10CS treatment reduced the L value of thigh and breast meat compared with those of the other treatments (p < 0.05). The a and b color values and pH values of breast and thigh meats were not affected by dietary CS supplementation (p > 0.05). Fat content of the meat decreased in the 30CS treatment compared to 0CS (p < 0.05). The results of the present study suggest that corn silage could be used up to 40% in the Turkish goose variety diet, without affecting the performance and meat quality, and thus, geese can be produced more economically.

Going Up Inflame: Reviewing the Underexplored Role of Inflammatory Programming in Stress-Induced Intrauterine Growth Restricted Livestock

The impact of intrauterine growth restriction (IUGR) on health in humans is well-recognized. It is the second leading cause of perinatal mortality worldwide, and it is associated with deficits in metabolism and muscle growth that increase lifelong risk for hypertension, obesity, hyperlipidemia, and type 2 diabetes. Comparatively, the barrier that IUGR imposes on livestock production is less recognized by the industry. Meat animals born with low birthweight due to IUGR are beset with greater early death loss, inefficient growth, and reduced carcass merit. These animals exhibit poor feed-to-gain ratios, less lean mass, and greater fat deposition, which increase production costs and decrease value. Ultimately, this reduces the amount of meat produced by each animal and threatens the economic sustainability of livestock industries. Intrauterine growth restriction is most commonly the result of fetal programming responses to placental insufficiency, but the exact mechanisms by which this occurs are not well-understood. In uncompromised pregnancies, inflammatory cytokines are produced at modest rates by placental and fetal tissues and play an important role in fetal development. However, unfavorable intrauterine conditions can cause cytokine activity to be excessive during critical windows of fetal development. Our recent evidence indicates that this impacts developmental programming of muscle growth and metabolism and contributes to the IUGR phenotype. In this review, we outline the role of inflammatory cytokine activity in the development of normal and IUGR phenotypes. We also highlight the contributions of sheep and other animal models in identifying mechanisms for IUGR pathologies.

Differences in Intestinal Barrier Development between Intrauterine Growth Restricted and Normal Birth Weight Piglets

Simple Summary

Animals with intrauterine growth restriction (IUGR) are defined as neonates born at term but with low birth weight and a characteristic shape of the head. A number of structural and functional modifications in the IUGR intestine affecting its digestive and absorptive function and impairing intestinal barrier function have been reported in the past. Far less is known about the immune system in the gut of IUGR pigs. Therefore, the aim of the present study was to evaluate the structures of the immune system of the gut mucosa in IUGR neonates. We found that the immune deficiency in the gut mucosa that results from restricted intrauterine development occurs at postnatal day (PD) 7, but it disappears thereafter within a week. However, all examined IUGR piglets had an increased number of intraepithelial leukocytes in the gut mucosa on PD 14. We have shown that the immune system of the gut of IUGR piglets is able to quickly compensate for the immunological deficiency postnatally and hardly shows any morphological disabilities in later life.

Abstract

Intrauterine growth restricted (IUGR) piglets are born at term but have low birth mass and a characteristic shape of the head. Impaired general condition, especially in intestinal function, leads to an increase in the occurrence of diarrhoea and high mortality in the first days of life. So far, the mechanical and immunological gut barrier functions in IUGR are poorly understood. The aim of this study was to microscopically evaluate the early postnatal changes in the gut mucosa occurring in IUGR piglets. Whole-tissue small intestine samples were collected from littermate pairs (IUGR and normal) on postnatal day (PD) 7, 14 and 180 and analysed by light microscopy. We found that in the IUGR piglets, the percentage of intraepithelial leukocytes was reduced in the duodenum on PD 7, but it increased in the proximal and middle jejunum both on PD 7 and PD 14, which suggested the development of an inflammatory process. The number of goblet cells was also reduced on PD 14. The average size of the Peyer’s patches in the distal jejunum and ileum showed significant reduction on PD 7 as compared to normal pigs; however, on PD 14, it returned to normal. On PD 180, we did not find any differences in the measured parameters between the IUGR and the normal pigs. In conclusion, we found that in one-week-old IUGR pig neonates, the gut barrier and the immune system structures display signs of retarded development but recover within the second postnatal week of life.