The Stomach Capacity is Reduced in Intrauterine Growth Restricted Piglets Compared to Normal Piglets

Intrauterine growth restriction and its impact on intestinal morphophysiology throughout postnatal development in pigs

Intrauterine growth restriction (IUGR) compromises fetal development, leading to low birth weight, and predisposes to gastrointestinal disorders. Pigs that suffered IUGR present poor postnatal development, resulting in great economic losses to the industry. The small intestine may be involved with impaired development, but studies investigating this issue are still limited. Thus, the present study aimed to investigate small intestine morphofunctional alterations in IUGR pigs throughout the production phases (birth to 150 days). IUGR pigs presented lower body weight from birth to the finishing phase (P < 0.05). Although histomorphometrical parameters were not affected during the pre-weaning period, their commitment was observed specifically in the duodenum of the IUGR group at older ages (P < 0.05). The most detrimental effects on the small intestine, such as deeper duodenum crypts’ depth, lower villus height:crypt depth ratio and absorptive area, increased apoptosis and lower proliferation of the duodenum epithelium were noticed at 70 days of age (P < 0.05). Additionally, IUGR pigs presented the lowest chymotrypsin and amylase activities at 70 and 150 days of age, respectively (P < 0.05). These findings may contribute to the elucidation of morphofunctional disorders of the small intestine in IUGR pigs throughout the different production phases, suggesting that poor postnatal development may be due to intestinal damage.

Piglet Morphology: Indicators of Neonatal Viability?

The morphological measures, crown-to-rump length (CR), and abdominal circumference (AC) have been suggested to be as good, if not better, than birth weight for predicting piglet performance. We explored the relationships between CR and AC, and piglet weights at birth and 24 h, to investigate their predictive value for piglet survival. Piglet weight and AC at birth and 24 h, and CR at 24 h were recorded for 373 piglets born to 31 sows. Morphological measures were categorised into two levels for weight and three levels for AC and CR. Further, AC and CR groupings were concatenated to create a new variable (PigProp) to describe the proportionality of piglet morphology. Proportionate piglets had equal CR and AC levels, and disproportionate piglets had contrasting levels. Birth AC was a good predictor of colostrum intake (p < 0.001) when accounting for birth weight, but 24 h weight and PigProp were good indicators of actual colostrum intake (p < 0.001 for both). The significant interaction of colostrum and PigProp showed that within the smaller piglet groups, those who had greater than 200 g of colostrum had higher 24 h weight and survival (p < 0.001 both). As expected, as body weight and colostrum intake increased, so did weight change to d 21 (P = 0.03 and trend at p = 0.1, respectively). A similar pattern was seen with increasing PigProp group (p < 0.001); however, piglets from the disproportionate group 1,3 had the greatest observed weight change (5.15 ± 0.06 kg). Our data show morphological measures may be more predictive of piglet viability in terms of both performance and survival than weight and there may be subgroups that have higher than expected chances of survival.

Piglet Viability: A Review of Identification and Pre-Weaning Management Strategies

Simple Summary

Neonatal piglet viability is decreasing in concert with the selection for ever-greater numbers of piglets born per sow per year. Their survival depends on the early intervention and management strategies used by production staff. This paper will review current and novel methods used to identify these piglets, some of the factors affecting their viability, and management strategies commonly used within production systems to improve their survival.

Abstract

Increased attention on the effects of the global push for a larger litter size has focused on the increased occurrence of piglets with decreased viability, which have lighter birthweights and a reduced ability to thrive in early life. To improve their odds of survival, interventions must be timely and targeted. This requires the early identification of low-viability pigs and appropriate strategies to manage them. Using novel measures such as abdominal circumference and crown to the rump length in conjunction with birth weight may provide an improved protocol for the identification of those at most risk of preweaning mortality. Further, identifying these at-risk piglets allows interventions to increase their colostrum intake and heat provisions shortly following birth. The appropriate management of the pre- and post-partum sows will improve the chances of decreasing the number of piglets born with lower viability. However, this outcome is constrained by limitations in resources such as technology and staffing. If these challenges can be overcome, it will allow for greater control and increased effectiveness in the implementation of current and new management strategies.

An incremental feeding pattern for Guangdong Small-ear Spotted gilts during gestation: effects on stillbirth rate and muscle weight of progeny

While an appropriate feed intake is crucial for the reproductive performance of sows, there is a lack of recommendations currently for feed allowance of Guangdong Small-ear Spotted gilts during gestation. The effects of 2 different feeding patterns during gestation on the reproductive performance of Guangdong Small-ear Spotted gilts were investigated by assigning 80 gilts to 2 feeding pattern groups with a randomized complete block design in accordance with initial body weight and back fat thickness, followed by treatment with an incremental feeding pattern (IFP) and a concaved feeding pattern, respectively, with no difference in total feed intake. The IFP group showed a significant decrease in the stillbirth rate (P < 0.05) and an upward trend in piglet mean birth weight (P = 0.06). Furthermore, the IFP group exhibited an increase in the weights of stomach, supraspinatus tendon, triceps, and psoas minor in neonatal piglets (P < 0.05). Overall, the results of the present investigation showed that IFP could significantly reduce the stillbirth rate of Guangdong Small-ear Spotted gilts and increase the muscle weight of progeny.

Using Nutritional Strategies to Shape the Gastro-Intestinal Tracts of Suckling and Weaned Piglets

This is a comprehensive review on the use of nutritional strategies to shape the functioning of the gastro-intestinal tract in suckling and weaned piglets. The progressive development of a piglet's gut and the associated microbiota and immune system offers a unique window of opportunity for supporting gut health through dietary modulation. This is particularly relevant for large litters, for which sow colostrum and milk are insufficient. The authors have therefore proposed the use of supplemental milk and creep feed with a dual purpose. In addition to providing nutrients to piglets, supplemental milk can also serve as a gut modulator in early life by incorporating functional ingredients with potential long-term benefits. To prepare piglets for weaning, it is important to stimulate the intake of solid feed before weaning, in addition to stimulating the number of piglets eating. The use of functional ingredients in creep feed and a transition diet around the time of weaning helps to habituate piglets to solid feed in general, while also preparing the gut for the digestion and fermentation of specific ingredients. In the first days after weaning (i.e., the acute phase), it is important to maintain high levels of feed intake and focus on nutritional strategies that support good gastric (barrier) function and that avoid overloading the impaired digestion and fermentation capacity of the piglets. In the subsequent maturation phase, the ratio of lysine to energy can be increased gradually in order to stimulate piglet growth. This is because the digestive and fermentation capacity of the piglets is more mature at this stage, thus allowing the inclusion of more fermentable fibres. Taken together, the nutritional strategies addressed in this review provide a structured approach to preparing piglets for success during weaning and the period that follows. The implementation of this approach and the insights to be developed through future research can help to achieve some of the most important goals in pig production: reducing piglet mortality, morbidity and antimicrobial use.

A dynamic mammary gland model describing colostrum immunoglobulin transfer and milk production in lactating sows

The physiology of the sow mammary gland is qualitatively well described and understood. However, the quantitative effect of various biological mechanisms contributing to the synthesis of colostrum and milk is lacking and more complicated to obtain. The objective of this study was to integrate physiological and empirical knowledge of the production of colostrum and milk in a dynamic model of a single sow mammary gland to understand and quantify parameters controlling mammary gland output. In 1983, Heather Neal and John Thornley published a model of the mammary gland in cattle, which was used as a starting point for the development of this model. The original cattle model was reparameterized, modified, and extended to describe the production of milk by the sow mammary gland during lactation and the prepartum production of colostrum as the combined output of immunoglobulins (Ig) and milk. Initially, the model was reparameterized to simulate milk synthesis potential of a single gland by considering biological characteristics and empirical estimations of sows and piglets. Secondly, the model was modified to simulate more accurately the responses to changes in milk removal rates. This was done by linking the ejectable milk storage capacity to the number of secretory cells rather than being constant throughout lactation. Finally, the model was extended to include the prepartum synthesis of milk and the kinetics of Ig into and out of the mammary gland. A progressive capacity of secretory cells to synthesize milk was used to differentiate the time between the onset of milk synthesis and Ig transfer. Changes in maximum milk removal rate, duration of milk ejection, and nursing interval exerted a great impact on the modeled milk output. Changes by ±60% in one of these parameters were capable of increasing milk output by 28% to 39% during the first 4 wk in lactation compared with the reference parameterization. This suggests that the ability of the piglet to remove milk from the gland exerts a key control on milk synthesis during lactation. Modeling colostrum as the combined output of Ig and milk allowed to represent the rapid decline in Ig concentration observed during the first hours after farrowing. In conclusion, biological and empirical knowledge was integrated into a model of the sow mammary gland and constitutes a simple approach to explore in which conditions and to what extent individual parameters influence Ig kinetics and milk production.