WEANING OF PIGS: OPTIMAL MANAGEMENT AND NEW CHALLENGES – an 8-part series
- What happens at weaning
- Objectives at weaning for a sow
- Piglet management around weaning
- Housing the piglet after weaning
- Feeding of the sow
- Piglet feeding at weaning
- Age at weaning
- Types of weaning according to the age of the piglet.
… and finally, a self-assessment exercise to recapitulate the whole topic.
Emilio Magallón Botaya – Veterinarian specialising in Economics and Pig Production.
Sara Beitia Delgado – Agronomist Engineer – La Almenara Farm
Pablo Magallón Verde – Technical Service PIC
David Roldan Feringan – Veterinarian-Granja La Almenara
Patricia Prieto Martínez – Veterinary Service Inga Food
Images provided by the authors
Weaning is one of the most critical moments in the life of the piglet, as it involves stress due to the separation from the mother, the change of facilities and the change in the composition of the diet, among other aspects, so it is essential to work carefully during this phase of production.
Management of the piglet during weaning
It is important to be clear about the objectives to be achieved during weaning of piglets. Likewise, the moment when the piglets are separated from the sow is key. All the actions we take with the animals during this period will have consequences later on. Even the design of the facility influences the final result.
OBJECTIVES AT WEANING FOR THE PIGLET
Obviously, our objective is to obtain a quality piglet at weaning, so that it will transition to the start at this stage, and we will have good technical and economic performance. A quality piglet will be one that:
- Is of an adequate age (minimum 21 days) and weight at weaning (minimum 6 kg on average with very little variability with respect to the average of the group).
- Optimum health status.
- High intake capacity (average daily intake (ADI) and high average daily gain (ADG).
- Adequate maturity and intestinal health.
The importance of each of these aspects is reviewed below.
- Adequate weaning weights
Variation of weaning weights is an unfavourable occurrence, which has been highlighted with the advent of hyperprolific genetics, mainly due to dispersion of birth weights and reduced milk and colostrum intake. It is very important to feed and water the sow correctly at this stage to maximise milk production. Weaning weight is a very important factor as it is related to mortality in the later rearing and fattening phases (see figure 1).
- Optimum health status
The most important factor affecting mortality is the health status of the piglets at weaning. The piglet progressively loses passive immunity after weaning before it has fully developed acquired immunity, so if piglets are of conflicting health origins, they will suffer multiple problems and post-weaning mortality will increase, this would then be increased if we mix piglets weaned from different origins.
- High intake capacity and Daily Gain
Regular and high intake of the piglet is necessary (figure 2). Some of the strategies to achieve these objectives are:
- Supplying piglets with the same type of feed as they consume in the final maternity phase.
- High quality diets with tasty and palatable ingredients.
- Handle the feed correctly, administering it several times a day, having extra dishes, working with mash in the first days, applying water with rehydrating agent in round hoppers…
- Water of biochemical and bacteriological quality, supplied at suitable temperatures.
- Climatic comfort. Temperatures at weaning of 28 °C.
- Adequate maturity and intestinal health.
Maturity and intestinal health are terms closely associated with the age of the piglet at weaning and the capacity for feed intake at that time.
The later the piglet is weaned, the more prepared the piglet is generally. When an immature piglet is weaned, digestive problems or the so-called “post-weaning syndrome” (diarrhoea, dehydration, loss of body condition and increased mortality) usually occur.
Related to these concepts we can find the 4 situations summarised in table 1.
Table 1: Summary of situations at weaning – Own elaboration.
Situation 1: very unfavourable
This is the most unfavourable situation, as the piglets are not only immature but also underweight. These piglets are very sensitive to the lack of “thermal comfort”. They have an immature digestive system so they need highly digestible ingredients, and the feed intakes achieved at weaning are extremely low so they will need nutrient dense diets.
Situation 2: unfavourable
Piglets with adequate weaning weights but inadequate intestinal maturity. This situation usually occurs with the heaviest piglets in the litter, so-called strict sucklers, who do not recognise the new food source at weaning, leading to a period of anorexia and weight loss.
In this situation it is key to get as many piglets as possible to start solid feed early with strategies such as creep feed. It is recommended:
- Use of mash or wet feed.
- Stimulate exploratory behaviour by feeding small amounts of feed several times a day.
- Stimulate water consumption.
- Use high quality and digestible diets and feed supplements to encourage intake.
The main reason why solid feed (creep-feed) is recommended during lactation is that its consumption promotes the familiarisation of the piglets with the type of feed they will receive in the future and, in turn, stimulates the maturity (Pluske et al., 2007) and enzymatic capacity of the intestinal tract.
Situation 3: favourable
In this case these are piglets with low weight, but adequate physiological age. Normally the smaller animals in each litter are more accustomed consuming and exploring the feed to satisfy the nutritional intake that they do not find in the mother’s milk. Thus, when transitioning, they are already accustomed to solid feed intake and show a better adaptation.
With this type of piglets, the main disadvantage is that they are very sensitive to environmental comfort, as they have low body reserves of glycogen and fat, so in this case good facilities and environmental conditions become very important.
Situation 4: optimal
In this case these are piglets with high weaning weights and adequate physiological age or intestinal maturity.
These piglets will have a more favourable starting situation than the rest, since, if the environmental conditions and facilities are adequate, and the feed is of good quality, they will have a good start at weaning (table 2).
Table 2: Temperature and ventilation recommendations throughout the post-weaning phase according to weaning day and season. Adapted from Queiles and Hevia (2006).
TIMING OF WEANING
The process of weaning, when the piglet is separated from the sow, is a key moment. It is a situation of great stress where the rearing place and feeding changes, new hierarchies are established with their new breeding partners, normally grouped by size and/or sex. It is therefore very important to do it correctly.
Time of day when weaning
As a general rule, weaning should be done first thing in the morning, after the sow has been given her first feed. The sow will be calmer, making it easier for her to lie down and suckle the piglets. In this way, the piglets are weaned with a milk feed before facing the latency period, defined as the time from weaning until the piglet has a constant and adequate feed and water intake (figure 3).
Also, for reasons of work organisation on the farms, it is best to wean early in the morning, so that the farrowing rooms can be emptied as soon as possible, and the cleaning of the rooms can begin. It is advisable to leave the rooms washed in the morning so that they can dry overnight. It is recommended to disinfect on dry before the sows enter the next farrowing cycle.
Der Zeitpunkt des Absetzens, wenn das Ferkel von der Sau getrennt wird, ist ein entscheidender Moment. Es ist eine Situation großen Stresses, in der sich der Aufzuchtort und die Fütterung ändern, neue Hierarchien mit ihren neuen Buchtenpartnern entstehen, da normalerweise nach Größe und/oder Geschlecht gruppiert wird. Es ist daher sehr wichtig, hier die richtigen Maßnahmen zu ergreifen.
Piglets, freshly weaned early in the day, prepared for loading and transfer by truck.
Separation of sow and piglets
The most common practice is to wean all sows in the building first and, once they have been moved to the “farrow-to-finish” house, proceed to move the piglets. Ideally, the pens for the weaners in the nursery barn are small or have a capacity for the number of piglets we weaned on average per sow to avoid stress by mixing litters. As this is very difficult in practice, we recommend the smallest possible pens, considering the economic constraints.
Recently, some breeder farms have been built with twice as many farrowing places as usual to be able to wean the piglets and carry out the whole post-weaning phase in the same farrowing house. The idea of making such heavy extra investments with this type of facilities aims to avoid the piglets the strong stress of creating new social groups at such a sensitive time as weaning. It is therefore important to evaluate the benefit from a productive and economic point of view. In these systems, the piglets are not mixed from birth to slaughter, except in the lorries for transfer from post-weaning (Site 2) to the feedlot (Site 3) where two litters are mixed only during transport, the piglets of each litter being marked with a different colour to be put back with those of the same litter in the fattening pigsties.
DAY OF WEEK OF WEANING
What day of the week do we wean?
On a pig farm, the most important tasks for its good management are:
Depending on the day of the week on which weaning is carried out, the covering and farrowing will fit better or worse into the working days of the week. The weekend should be the time when there is the least amount of work on the farm, due to the lower presence of labour. It is therefore very important to choose the right day for weaning. The following farm-specific aspects should be considered:
- Duration of gestation
- Weaning – oestrus interval
- Weaning – service interval
- Breeding schedule
A. Weaning on Thursdays
Traditionally on farms with sows of average gestation around 114 or 115 days, weaning is done on Thursdays, so most sows are covered on Mondays and Tuesdays and farrow on Thursdays and Fridays.
The 4-day weaning interval between weaning and main oestrus allows the bulk of the services to take place on Mondays and Tuesdays, thus avoiding the weekend. The 16 weeks and 3 days gestation length means that the bulk of the group farrows on Thursdays and Fridays, thus avoiding a lot of weekend farrowing.
The main disadvantage of weaning on Thursdays is the control and processing of the litters. Follow-up and adoptions of piglets during the first 3 days of life are critical to reduce maternity losses.
Depending on the day weaning takes place, they will fit the coverings and farrowing better or worse within the working days of the week.
Iron supply (and tail docking and teeth grinding) is another of the farm’s most labour-intensive tasks related to farrowing. Weaning on Thursdays, ideally the next batch of sows should be brought into farrowing on Sunday. That way there is enough time for cleaning and disinfection (3 days) and the sows enter 4 days before farrowing. However as routine work during the weekend is to be avoided, another option is to have them enter on Monday, 3 days before the expected farrowing (table 3). This is probably the most frequent distribution of tasks on farms with a single weekly weaning on Thursday. The work plan is good, but it implies proper litter control during the weekend.
In recent years it has been found that hyperprolific sows have longer gestations, lasting two or three days longer, between 116 and 117 days, so weaning on Thursdays moves farrowing to the end of the week when there is less staff on the farms. Piglet mortality in farrowing takes place during the first 3 days of life, 80%, which is when the piglets require the most attention.
Die gängigste Praxis besteht darin, zunächst alle Sauen Auszustallen und dann mit dem Umsetzen der Ferkel fortzufahren. Neuerdings sind einige Ferkelerzeuger dazu übergegangen, die gesamte Ferkelaufzucht im Abferkelstall durchzuführen. Die Idee zielt darauf ab, den Ferkeln den hohen Stress zu ersparen, der mit der Bildung neuer sozialer Gruppen zu einem so sensiblen Zeitpunkt wie dem Absetzen verbunden ist. Dies erfordert allerdings eine Verdoppelung der Abferkelplätze (oder Halbierung des Sauenbestandes). Es ist daher wichtig, den Nutzen unter produktiven und wirtschaftlichen Gesichtspunkten zu bewerten. In diesen Systemen werden die Ferkel von der Geburt bis zur Schlachtung nicht gemischt, außer beim Transport zum Maststall (Standort 3), wo zwei Würfe nur während des Transports gemischt werden. Die Ferkel jedes Wurfes werden farblich unterschiedlich markiert, um dann im Maststall wieder mit ihren Wurfgeschwistern zusammengestallt zu werden.
Table 3: On-farm tasks with only one weaning per week on Thursdays
Table 4: Weekly work plan
4A: Recommended weekly work plan for lines at 114* and 115** days of gestation.
4B: Recommended weekly work plan for lines at 116/117 days of gestation
B. Weaning at weekends or on Mondays
Thus, with hyperprolific sow genetics that have longer gestations, weaning should be carried out at the weekend or, even better, on Mondays in order to have farrowing at the beginning of the week.
On some large farms, weaning is done every day of the week to make better use of maternity places, but this system is not advisable because it complicates management. Some farms wean two days a week, but this practice, which maximises the use of the maternity units, complicates management and work on the farms (table 4).
The disadvantage of weaning on Mondays with hyperprolific genetics is that the bulk of coverings are on Fridays and Saturdays, and if weaned on Sundays many of the farrowing occur at the weekend. In both cases both litter control and litter processing are done during the week when all the staff is working on the farm.
This series of articles was first published in the professional journal SUIS.