MILK QUALITY OR QUANTITY?
In the last 2 nutricles, we covered the nutritional strategies to prepare well the gilt to her first pregnancy and then to ensure a long and productive reproductive life. Today, we are going to discuss about the strategies to maximize the production of colostrum and milk during each lactation.
The importance of the quality and quantity of both colostrum and milk do not need to be explained. By feeding well the piglets during their first weeks of life, we are ensuring they have an optimal development.
To improve the quality of colostrum, we need to work on the immune status of the mother. The immune products found in colostrum are predominantly derived from sow’s serum, and this process occurs over the last 4 weeks of the gestation. Applying nutritional strategies during the last 4 weeks of gestation can enhance the quality of colostrum (higher Ig content and high fat content). Several strategies are advised to boost sow immunity including live yeasts and yeasts extracts, tributyrin, conjugated linoleic acid and monolaurin.
Monolaurin is a fatty acid with 12 carbons. Because of its medium chain and its amphiphilic characteristics, Monolaurin is absorbed through the lymphatic system without being destroyed by the liver like most of the compounds that go through the portal vein. Monolaurin is therefore one of the only additive that will end up in the colostrum and protect the piglets. Lauric acid is a natural component of all mammals milk. The addition of monolaurin in lactation diets is therefore a way to leverage a natural pathway to provide anti-microbial and anti-viral compounds to piglets in their early life.
The increase of fat content in the diet at the end of gestation will increase as well the lipid portion of colostrum which could positively contribute to the piglet development during the first few days of life.
Regarding the colostrum and milk quantity, the strategies are multiple but they start with the farrowing process itself. The colostrum quality declines as the lactation progresses so those piglets born first get the best quality and highest quantity of colostrum. It is therefore important to ensure a farrowing process as short as possible. There are 3 major dimensions to study.
AVOID OVERWEIGHT SOWS
Sows should not be overweight. Ensure sow body condition is corrected during the second trimester of gestation and that sows are offered a higher plan of nutrition in the last trimester (see last month nutricle). Sows should have a body condition score of 3.0-3.5 at the time of farrowing. If the sows are overweight, they will experience difficult farrowing. Sows with a history of stillborn pigs should be assisted to avoid complications and long farrowing
CALCIUM ABSORPTION Calcium and Vitamin D are two essential nutrients for ensuring strong uterus contractions and accelerating the farrowing. Calcium is indeed responsible for moving troponin away from the site where myosin is supposed to act to exercise the contraction force.
We cannot increase the calcium carbonate content in the diet without creating problems (antagonism with phosphorus, increase of acid binding capacity in the stomach). The Calcium strategy needs therefore to focus on increasing its absorption to ensure that we cover nutritional requirement especially important at that stage. The limiting factor for absorbing calcium is not its import from the gut to the enterocytes but rather its export from the enterocytes to the blood. For this export process, the calcium will use a CaBP (calcium binding protein) that is built mainly from arginine and vitamin D. Nutritionists should therefore be very attentive to the level of arginine and vitamin D supplied to the sow during lactation.
Another strategy for mobilising calcium in the blood would be to reduce dietary dEB (dietary electrolytes balance).
The dEB is the balance between the cations (sodium and potassium) and the anions (chloride) in the feed. When we are increasing the quantity of cations (Sodium and Potassium) in relation to the anions (chloride), which happen when we increase dEB, we are bringing more (+) than (-). To maintain neutral situation, the enterocytes will excrete some H+ resulting in an increase of blood pH. To ensure a constant blood pH (around 7.3), the pituitary gland will react by mobilising uptake of calcium into the bones resulting in normalization of the blood pH. By removing the 2+ from calcium out of the blood, we are maintaining neutral electrical status without having to excrete any H+). – see our nutricle “Can blood be acidic?”
It works the other ways around when we are increasing anion as chloride (decrease dEB). Too much negative charges will lead to a mobilization of calcium from the bones to the blood as a compensation mechanism to avoid the absorption of H+ from the intestine that would have led to a decrease of blood pH. As result, calcemia will increase. Increasing calcemia by reducing dEB is exactly what the sows need around farrowing. The optimal decrease of dEB between the lactation and gestation diet is estimated at 50-100 mEq. The problem is that it is difficult to reduce the balance between sodium and chloride as both are coming from salt. We need to replace salt by a source of sodium like sodium bicarbonate or sodium formate that does not carry chloride. 1kg of Sodium formate per ton of feed will reduce dEB by 15 mEq. The sodium formate has a doubleadvantage versus the bicarbonate. It does not affect the diet acid binding capacity (bicarbonate increases stomach pH) and it brings some formate that will demonstrate antibacterial properties in the gut. As Calcium is an important component of milk, a proper Calcium strategy will contribute to higher milk production. Indeed, Calcium level in the milk is not varying much. When the sow does not have sufficient calcium, instead of reducing calcium concentration in the milk, she is reducing the milk quantity. Nutritionists should therefore pay a special importance to sow calcemia around farrowing and during lactation.
This dEB strategy together with the use of precursor of Arginine to improve dietary calcium absorption demonstrated strong effects on effective parturition, increase of number of piglets born alive, faster onset colostrum and milk production and higher piglet survivability. CONSTIPATION Constipation could be a major obstacle for proper farrowing for two reasons. Firstly, because constipation can represent a physical obstacle to the passage of piglets in the uterus. Secondly, because constipation will trigger complications, often not identified by farmers – see our nutricle “Constipation is darker than it looks” Constipation -> No more transit -> Bacterial development-> Production of enterotoxins -> Reduction of prolactin hormones -> Decrease of colostrum and milk production up to -40% Indeed, the enterotoxaemia caused by the constipation will have a direct effect on the level of prolactin produced by the sow as it was demonstrated by Prof Chantal Farmer in a 2001 publication. She injected in sows 3 different E.Coli enterotoxins from E.Coli and she noticed a reduction of the concentration of prolactin in the blood that can last up to 8 hours.
Constipation often happens few days before farrowing because of a reduction of daily fibre intake. Indeed, we are changing diets from a gestating diet with a high fibre level to a lactation diet with lower fiber level. Moreover, the sows are naturally reducing the meal size before the farrowing day. As a result, the quantity of fibre present in the gut can be reduced up to 5 times. As insoluble fibre is the substrate for gut motility, a significant decrease of fibre intake leads to a slow down of the transit and then constipation.
The negative effect of constipation is largely underestimated in Asia, especially if the sows do not have access to clean and fresh water in sufficient quantity. Farmers often get used to the situation and do not work to prevent it.
To limit this syndrome, it is critical to ensure a sufficient level of fibre both in the gestating diet (around 22% of total dietary fiber) and the lactating diet (18% of total dietary fiber) which can be difficult (and therefore expensive) to reach by nutritionist when using only standard ingredients – see our nutricle “Is it Soluble or Insoluble?”
By increasing fibre level in the lactating diet, we are accelerating transit and increase feed intake. This strategy is particularly important in hot climate where the heat is naturally depressing sow feed intake. To promote higher colostrum and milk production, it is critical to boost sow feed intake during lactation. We already shared several strategies in previous nutricles as the use of net energy instead of metabolisable energy (see our nutricle “Net is better than gross”) increase fat level, multiply number of meals and provide fresh water.
Around farrowing, we need to ensure sows are not off feed. Sows will naturally reduce their appetite prior to farrowing but it’s important we don’t withhold feed from her. She is at risk of low glycogen levels and will experience farrowing fatigue if her energy levels aren’t sufficient.
Split suckling is an effective management tool to enhance the distribution of colostrum intake. Once the last piglet is born (the placenta has been expelled), you should separate the first 4-5 born piglets by placing them into a tub under the heat lamp and set a timer for a maximum of 40 minutes. You can then ensure that the last born piglets access the anterior teats. This will allow them to access more colostrum with less competition. We are targeting a minimum colostrum intake of 250gm/piglet. If the sows farrowing has been very long, the litter is very large or the piglet vitality is poor, you may need to split suckle twice (selecting 4-5 different piglets for the second round).