Supplementation in newborn piglets is a key factor to focus on within the pig industry. In the last 10-15 years, there has been a tendency to select the most prolific sows, with litters greater than 12 live/calving piglets or even greater than 15 in some cases.(Guo et al., 2015) This however, results in greater heterogeneity regarding birth weight.
Larger litters have higher energy and nutritional needs as well as greater health challenges (Baxter et al., 2013; Rutherford et al., 2013).
- Fetal and neonatal deaths can be attributed to physiological immaturity and lack of energy storage in piglets, often resulting in weak animals.
- In large litters, there is an increase in low-weight piglets’ frequency of (<1 kg). These piglets find themselves at a disadvantage when competing for colostrum.
The epidemiology of pre-weaning mortality is complex, however, lack of energy is the main cause.(Lin et al., 2015) Resulting in hypothermia, and leading to mortality due to crushing, weakening, amongst other causes (Cara-mori et al., 2010).
The use of liquid diets enriched with milk and fat, has had good results, positively affecting the growth of small piglets during lactation or after weaning.
This review aims to characterize different feed sources that can contribute to adequate energy supplementation, reducing mortality and improving piglet performance during the lactation phase.
Importance of energy consumption in newborn piglets
Appropriate energy intake for newborn piglets is especially important for maintaining body temperature.
- Fat reserves of newborns are low (about 20g/kg) and do not contribute significantly to their energy supply, since the capacity to undergo gluconeogenesis in this period is still not fully developed (Boyd et al. , 1982).
At 32-34ºC, glycogen stores of piglets that did not have access to colostrum will be scarce within 16 hours (Theil et al. , 2011).
These reserves can be depleted in 10 to 16 hours at 18-26ºC, depending on the environmental and body conditions of the piglet at birth.
The consequences of the depletion of this energy source are hypoglycemia, hypothermia and death (Xu and Cranwell, 2003). The first three days of life are considered the most critical phase. This is due to the challenge of maintaining energy balance, when the energy source is quickly depleted.
[register]It is known that with litter size increases, there is greater competition for colostrum and milk. Which many times leads to some piglets not being able to ingest sufficient quantities.
- Therefore, other sources of energy precursors may be important for metabolic homeostasis.
Thus, vegetable oils have been studied with the aim of improving energy intake and immune system response in newborns (Santos et al. , 2015; Turner et al. , 2015).
During the first days of life, high levels of lactase activity within the small intestine favor the use of dairy substitutes as an alternative energy source. (Xu and Cranwell, 2003).
These nutrients have also shown to be efficient in improving performance and immunity through their amino acids’ contribution. Which supports their use during this early stage.
Use of lipid sources in nutritional supplementation of piglets
Colostrum contains approximately 3.5% lactose and 5.9% fat. Both of these are quickly available for metabolism and heat production (Xu and Cranwell, 2003).
In newborn piglets, oral supplementation with coconut fat (composed of MCFAs) during the first 12 hours can provide better survival conditions with a reasonable energy intake and without a decrease in colostrum consumption (Chiang et al., 1989).
Benevenga et al. (1989) suggested that medium-chain triglycerides can be used as a supplementary energy source for low birth weight piglets. This is not the case for medium-weight piglets (≤1200kg) which do not benefit from fatty acid supplementation in the same manner. Subsequently, Domingues (2001) observed a numerical increase in total serum protein values for piglets supplemented with coconut fat.
- In piglets weaned at 21 days the addition of medium-chain triglycerides in the diet can have similar results to diets with antibiotics.
MCFAs are also studied because they have protective effects on intestinal structure. Resulting in increased villus height, reduced crypt depth, and an increased villus/crypt ratio (Diericket et al., 2003).
Different concentrations of n-3 and n-6 PUFAs were observed in sow milk. Such observations were made in studies where sows received n-3 PUFA supplements at the beginning or end of gestation and continued to receive supplements until at least 14 days after calving (Boudry et al. , 2009; Binter et al., 2011).
- Supplementation with PUFA n-3 and n-6 was effective for the recovery of intestinal lesions in malnourished piglets, promoting greater enterocyte growth and the reduction of histological alterations caused by malnutrition (López-Pedrosa et al. , 1999).
Pure glycerol is an energy-rich product (3682 kcal EM/kg for freshly weaned piglets), which can be easily digested and metabolized (Kerr et al., 2009). In addition to this, several studies evidenced positive effects of glycerol on amino acid retention as cited by Cerrate et al. (2006),
- This is due to the fact that glycerol is able to spare gluconeogenic amino acids by inhibiting the activity of enzymes like phosphoenolpyruvate, carboxykinase and glutamate dehydrogenase. Which as a result favors body protein deposition.
Several studies have been conducted on the use of glycerol as an energy source for pigs, from the transition stage to growth and completion. Being able to demonstrate the great potential of this product as an energy source (Lammers et al., 2008; Zijlstra et al., 2009; Kerr, 2011).
Once absorbed, glycerol can be converted to glucose through gluconeogenesis or oxidized for energy production through glycolysis and the Krebs cycle (Guyton and Hall, 2006).
Escudos et al. (2011) reported that supplementation with 5% glycerol reduced blood urea, suggesting better nitrogen use compared to diets containing 0 or 10% glycerol.
Final considerations
Rapid evolution of genetics within the pig industry needs to be accompanied with technological innovations at the nutritional level. Literature on newborn piglet supplementation is varied and should be related to the different sources used, such as carbohydrates, lipids and/or amino acids.
Nontheless, energy supplementation soon after birth is viable. This is especially true for piglets that are born with low weight. Making a contribution towards the best use of these animals’ genetic potential.
Source: Manzke et al., Arch. Zootec. 65 (252): 585-591. 2016.
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