Note: Although this was Number 3’s third successful litter, we had to clip the piglets’ teeth because she got angry while nursing. We had the same issue with Auntie Brownie who farrowed on July 29, 2018, during a hot and humid season. Humidity is particularly high, which is more difficult for gestating and farrowing sows. There were 13 piglets in this litter, which is one of our highest, and thus a higher incidence of crushing was expected. Our sows seem to want to keep only 8 piglets per litter.
Gestation 115 Days Serviced by Pinky Boar June 30, 2018. Farrowed October 23/24, 2018.
Nest building started at 5:45PM, October 23. Number 3 took some time building her nest, spent a lot of time just standing in the middle of the pen, looking around, assessing the nest and environment. There might’ve been insufficient nesting material. Must take note of the quantity and quality of nesting material next time.
Farrowing, October 23, 2018 at 11:44PM
Farrowing went on until around 3:30AM October 24. At around 4:10AM, Number 3 got up and lay on a piglet for a minute. She must’ve known she was lying on a piglet so she got up, rooted the nesting material and lay down again, letting the piglets nurse. When piglets are unable to squeal when laid on, the mother is often but not always unaware of what has happened.
October 24 – Around 6AM I noticed one dead piglet, a large male, most probably due to crushing. In the night, Number 3 had already crushed 2 piglets including this one. The second piglet was hidden underneath the nest and I discovered it only 3 days later.
In the video above, Number 3 is very tired and overheating. Trevor tries to cool her down with some water. In hot and humid climate, water might increase humidity. We are installing a fan to correct this problem.
In the video above, the piglets are 1 day old. Number 3 lies on the nest, reluctant to nurse. It is in the early morning and she is panting as the heat and humidity builds up. October and November are hot and rainy months.
Fighting amongst piglets during nursing begins by 12:18PM and Number 3 gets upset by this. Although Number 3 does her best to adjust her position whenever there is fighting, as well as getting up immediately when a piglet squeals, the situation worsens as Number 3 gets more exhausted and stressed by the heat and the pain from piglets’ teeth whenever they fight at her teats. By noon-time the following day, we decided we need to cut piglets’ teeth.
October 25 – Teeth clipping done at 3PM. Nursing situation is much better after teeth clipping. During this time, we saw a piglet had an injured front leg but this got better over the next several days. This piglet remained very active and became one of the largest in the litter despite the injury.
In the video above, day old piglets have discovered the piglet escape hatch and explore the ‘Piglets’ Restaurant’ where fresh soil and green forage is provided. The piglets sample the soil right away and this is their source of iron when iron supplements are not available.
October 26 – While rescuing a smaller brown piglet from crushing, I found a dead piglet, one of the larger ones, crushed during fighting perhaps or during heat stress at high noon.
In the video above, piglets are 2 days old. Video was taken at night. Piglets’ teeth have been clipped so the mother no longer gets angry during nursing. However, the mother still feels very exhausted and may be suffering from heat stress. She is lying and adjusts her position, pushing the piglets with her hindquarters. This and numerous movements make it appear as if the mother is careless. She also doesn’t get up immediately when a piglet is overlaid or stepped on. Note the piglet with a limp. This piglet’s foot was probably stepped on by the mother. Piglets recover well from these types of injuries.
October 27 – I found a dead piglet in the nest in an advanced state of decomposition indicating it may have been crushed on the first day or may have been stillborn.
In the above video, piglet are 4 days old and quite active after teeth clipping and no iron supplements. Soil was spread in the creep space and ‘Piglets’ Restaurant’ which the pigs eat since day 1.
November 2 – I found a piglet crushed, a large male piglet, 9 days old. This is very disappointing. Hot and humid, Number 3 is panting heavily, and the crushing might be due to heat stress. We are implementing some changes which we hope will reduce heat stress and the incidence of crushing.
We separated Number 3 from her piglets on November 28. Piglets were 35 days old but already eating solid food. We had no serious scour problems. Piglets were sold 10 days later.
The Problem of Crushing
For 2019, we are implementing changes which we hope will reduce the incidence of piglet mortality due to crushing. See Piglet Crushing Management.
Here are some videos of Number 3’s piglets
In the video below, while her piglets are out in the garden, Number 3 plays in her pen. I get very nervous when such a big pig starts running like this with little piglets around her. So it is good that piglets are able to go out so the mother has the chance to relax.
Note: This is the first time we had to clip piglets’ teeth because Auntie Brownie, now on her third parity, got very angry whenever she nursed her piglets. No teeth cutting was needed on first and second parity. The months June-July were very hot and humid. I think this aggravated the problem of mastitis, making Auntie Brownie very sensitive to piglets’ teeth. This time, we also had a high crushing number of 4 piglets, with 12 live born piglets. 8 were weaned successfully.
Gestation 111 Days Serviced by Pinky Boar on April 9, 2018. Farrowed July 29, 2018.
During gestation, Auntie Brownie made loud grunting noises indicating call for bath. I gave her a few baths during high daytime temperatures. She also created a pit, cooled it with her urine and lay in it. Unfortunately, high humidity and dew point during these months didn’t help. We have changed feeds, employ wet feeding, installed an electric fan for Auntie Brownie’s next farrowing and see if we will get better results.
Nest building started a day before farrowing. I saw Auntie Brownie pawing the ground so I gave her some dry banana leaves. She took it and began nest building, then rested. She kept at this for the whole day, seemingly too lazy to build a satisfactory nest. This must be because of the heat and humidity.
Farrowing, July 29, 2018 at 10AM
The farrowing was without incident, 12 piglets born alive. However, within the first hour of birth, piglets started fighting which upset Auntie Brownie. Although fighting at the teats within a few hours of birth is not unusual, I found it unusual that Auntie Brownie got hurt so easily, and the fighting was frequent. I think that piglet fighting is an indication of poor milk flow. This may confirm the problem of mastitis or agalactia due to heat stress.
In the video above, Auntie Brownie is very tired and obviously having problems nursing her 1-day old piglets. Intervention is needed when this happens.
July 30 – 2 piglets were crushed to death and 1 was injured by overlaying. It seemed that Auntie Brownie was deliberately overlaying her piglets because she was hurt and upset by them fighting at her teats. Brownie’s teats seemed hard when I pressed them in the morning, but by late afternoon, her teats seemed much softer. It is possible that her teats were sensitive because of mastitis. I also wondered if the piglets’ teeth were sharper than the usual we’ve had before. I inspected the teeth of one of the dead piglets and I saw needle teeth that were thin and sharp, instead of the usual triangular shape with the pointed tip. Not all the piglet’s teeth are like that, and I am not sure if such teeth do make a difference.
July 31 – Teeth-clipping went well this morning, there are 9 piglets left. 1 piglet got crushed last night. Brownie drank water but did not eat. White discharge. Piglets went to the mother to suckle and the situation seemed better, although nursing is less frequent (every 1-2 hours); hoping later nursing will be on regular. I hope things progress from now on and that the mother quickly recovers.
August 1 – It is Day 3. Suckling is much more peaceful since teeth clipping. The injured piglet remains feisty and active. Piglets look forward to exploring the Escape Hatch/Restaurant/Garden after nursing, particularly brightens up sluggish piglets. The injured piglet seem to be the first to want to go out. Nursing was hourly and sometimes 15-30 min intervals. Brownie is drinking and eating well. She is getting Amoxicillin antibiotics in her water (for 3 days).
In the video above, piglets are 6 days old and go out into the garden several times each day, particularly after nursing.
August 5 – Piglet got crushed this afternoon. We were unable to revive it. This was a 7-day old piglet, very active and was seen fighting with litter-mates just a few hours ago. I believe this is accidental crushing, which happens when the piglet is unable to squeal so the mother is unaware that a piglet is being laid over. The piglet may have been very tired and was deep asleep.
The ground in front of the trough has become tough and slippery and this area seem to be where crushing fatalities often occur. This area will need to be dug up and wood shavings spread to soften the ground and reduce slipping.
In the video above, piglets are 11 days old. The piglet with the injured leg fights for milk. She is also the first one to go out of the escape hatch to play in the garden.
Video above shows Auntie Brownie interacting with her piglets, very much aware that I am filming her. With 4 or possibly 5 piglets crushed by the mother, the piglets have developed a very cautious relationship with their mother who at the same time is their source of life and nutrition. Through ambivalent socialisation with their mother, the ability of piglets to develop this alertness at the first few hours of birth is crucial to their survival.
Weaning the Piglets
September 3 – Auntie Brownie separated from her piglets, now about 38 days old. However, we put the runt with her, the one that got injured by crushing. We usually sell piglets at 45 to 55 days old, or after all signs of scour, if any, are gone. There was some scouring in this litter starting on day 2-3 after weaning which was treated with Apralyte. Because of early treatment, scours were gone in a few days.
The Problem of Crushing
For 2019, we are implementing changes which we hope will reduce the incidence of piglet mortality due to crushing. See Piglet Crushing Management.
We have been keeping pigs for almost 9 years now and our accommodation for pigs, in a tropical backyard setting, have changed over the years. Here’s how things developed, plus an outlook for the future.
The Tethered Pig
As often practised by people in our village with very limited space and resources, we kept pigs on a leash and tied them to a tree during the daytime and then tied them under the house at night. If we had 2 pigs we had to keep them a distance from each other. Otherwise their leash would get tangled up and they may get hurt. Our first fatteners and a gilt were tethered pigs. When our gilt was about to farrow, we built a little pen for her. The pigs were fed in modified large plastic containers.
In the video below, the gilt Miss Piggy is tethered next to the goat house under a tree.
The video below shows a conventional concrete pigpen commonly found in our village. A boar and 5 sows are kept in individual pens.
The Penned Pig
We started with a small pen, about 8 square meters. It was made of strong bamboo and had nipa palm fronds for roofing. The flooring was just soil with some sawdust and rice hull mixed in. We kept a fattener in this pen. Later, we enlarged the pen to about 20 square meters. We raised our first boar, kept two gilts, had a sow farrow in this larger pen. We also kept 1-2 fatteners at a time here.
In the video below, Bootleg, who had just undergone hernia repair surgery, plays ball in a pen made of bamboo and wood.
In the video below, sow Number 3 farrowed for the first time, to 4 piglets in this bamboo pen. The piglets are 2 weeks old in this video. We installed a creep rail with warming lamp which the piglets never used! In the latter part of the video, Number 3 is shown eating from the wooden trough. After many months of use, water leaks out of the trough and floods that area.
Later, we built two more pens of about the same size, so that we could rotate the pigs and allow the empty pens to fallow and get cleaned up. The two new pens were made of coconut and some scrap lumber, bamboo, nipa and tarpaulin roofing. The pigs were fed in large plastic container or modified rubber tires. Later, we decided to build troughs out of mahogany planks. The troughs can be filled with food and water from outside the pens. The pigs couldn’t turn over the troughs so the food and water didn’t get spilled. This made feeding much easier. We tried installing pig drinkers but as the pigs got bigger they destroyed those things.
In the video below, five new piglets enjoy the soil and grass in a large pen made of coconut lumber, some bamboo and scrap pieces of wood. In less than a week, all that grass is gone.
In the video below, 3-day old piglets play fight in the same pen shown above. The piglets were born in this pen.
Over 2 years, we used these pens. We kept a boar, 3 sows, a few fatteners in these pens. We had 4 farrows in these pens. Over the years, these pens required a lot of maintenance and emergency repairs. The wood rotted and pigs escaped several times. Ducks went into the pens and got eaten by pigs. The roof rotted and leaked when it rained and flooded the pens with mud. The pigs loved the mud but when there was too much mud, there was no dry place for them to sleep in. We desperately needed better pens.
In the video below, 2 young boars are fed on a tire cut in half. When it rained and the pen became very muddy, it became impossible to keep feeding the pigs this way. We got stuck in the mud!
The pens have half meter walls made of concrete and over that are fences made of strong mahogany wood planks. The fences have gaps for good ventilation and sun exposure. The fencing for the boar pen is higher (about 4 feet high) than those for the sows (about 3 feet high) because the boar is much bigger and can jump out of the pen. These pens are a spacious 22-25 square meters. The farrowing pen has a creep rail and an escape hatch. The escape hatch allows the piglets to go out into the garden. The farrowing pen has LED lighting and an extra socket for a heat lamp for piglets born in the cool season.
All the pens have concrete troughs built along the side wall of the pen. The troughs can be filled with food and water from outside the pens.
In the video below, sow Auntie Brownie is with her piglets in the maternity pen. The trough and creep rail is visible, as well as the escape hatch behind the creep rail.
Two of the pens are right next to each other with a gate in between. The boar stays in one pen and the sow is placed in the other. This boar-sow contact allows the sow to go in heat and makes it easier for us to detect when the sow is in heat. If it is time to mate the pigs, we just open the gate in the middle (see video below).
The roofs of these pens are made of galvanised iron sheets, built at a height of 9-12 feet for ventilation and sun. Unfortunately, the roofing material are thin and may need to be replaced in a couple of years. The gates of the pens are made of galvanised iron pipes which we painted over. The floors of the pens are soil mixed with saw dust and many other natural materials such as dry banana leaves and coconut leaves. We have also sprayed the floor of the pens with lactic acid bacteria solution (LABS) and added some IMO (indigenous microorganisms).
We need to keep the sow more comfortable in the farrowing pen during the hot summer months. We plan to put an electric fan in the farrowing pen and direct it towards the creep rail. We hope this would encourage the sow to farrow next to the creep rail which will protect the piglets better from crushing.
We need to fence an area of the garden around the farrowing pen so that when the piglets are out in the garden, they will not wander away outside of the property where they could be in danger (particularly by dogs). The fenced area needs to be large enough for the piglets to run around in and should at the same time keep the piglets away from sections of the garden where we don’t want them to go. The fences should be short (2 feet or less), strong but not imposing and should be made of material where vine plants can grow over. At the same time, the fences should not get in the way when we rotate sows from one pen to another.
Coconuts and mahogany pods fall on the roof of the pens and if this persist, the roofs will be destroyed. We plan to cut these trees. This will allow the fruit trees, native trees and shrubs already growing in the area to flourish and provide shade and forage for the animals.
We would also like edible fruiting vines to grow up the pigpens and over the roof. This will provide shade and food for humans and animals. We are working to have more vegetation grow around the pigpens.
We will also have to continue using IMOs and LABS in our pigpens. We think that these, plus sufficient ventilation and sunlight, destroy pathogens in the pens. When we fallow a pen, that’s also when we harvest good organic compost which enrich the gardens where soil is very poorly and rocky.
Basic Principle of Natural Environment for Housing Pigs
Below is a good video that explains the design principle of housing for Natural Farmed pigs. We did not implement this design completely in our pigpens but we do our best to keep the principle of re-creating something as close as possible to a natural forest environment, the natural home for the domestic pigs’ ancestor, the wild boar.
Here is another interesting video (below, in 3 parts) that explains the importance of environment, welfare and public health in pig farming. Several examples of sustainable and profitable systems shown may be useful for those seeking better ways of raising pigs.
Stocking Densities for Pigs
There are several recommendations based on welfare regulations on stocking densities for pigs. Most of the figures are based on accommodation in temperate or non-tropical settings. We believe that because of high temperatures and humidity in the tropics, the minimum space required for pigs should be larger than those recommended in the link below.
We will post updates once we have implemented the improvements planned for next year. If you have any questions about our pig accommodations, don’t hesitate to leave a comment and we’ll do our best to reply.
According to studies, average pre-weaning mortality in loose farrowing systems commonly range from 20-33%. This is twice greater than that normally occurring in confinement farrowing crates. The major cause of piglet mortality in a loose-farrowing system is piglets being laid on by sows (often called ‘piglet crushing’). A survey of 40 producers using loose-farrowing systems in the midwestern United States indicated that average pre-weaning mortality of piglets was 26.4% and average litter size weaned was 6.7.
Our Figures in Loose-Farrowing Systems
Our sows farrow in a loose-farrowing system, a pen of about 22 square meters. The flooring is a mixture of soil, wood shavings and other dry and green organic matter. The pen has a small fenced area (creep space) and an escape hatch for piglets. The sow is given nesting materials (dry banana leaves) on the day of farrowing. Our current crushing rate – with minimum supervision – is 20%. Mortality due to disease is 0%. The sows, now 3 years and 4 months of age, are healthy and strong, and our piglet post-weaning mortality rate is 0%. The average litter size weaned at 45 days is 8 piglets.
Note: Minimum supervision means we do not intervene during farrowing. We provide nesting materials as soon as the sow asks for them and then we leave the sow alone, watching at a distance of 25 feet. We save piglets from crushing when we see or hear them. Because of minimum supervision during farrowing, we are often unable to determine stillbirths or whether piglets were live born and died through crushing. We have decided to include these mortalities in our crushing statistics.
Farrowing Crates and Farrowing Pens
The use of farrowing crates with supervision can reduce crushing mortalities down to 5-10%. However, piglets and sows raised in these conditions often have a higher incidence of disease and post-weaning mortality than their loose-farrowing counterparts. The use of farrowing crates are under scrutiny for welfare concerns and their use has been banned in some countries. Apart from pasture and loose-farrowing options, there are new designs of farrowing pens to address the concerns of producers. Below are two examples (first and second video).
The videos below show strip-grazing farrowing paddocks and indoor and outdoor systems in the UK.
How we try to reduce the incidence of crushing in a loose-farrowing system with minimum supervision
Give sufficient nesting material. The nesting material of choice in the tropics is dry banana leaves. An abundant amount is necessary, between 15 to 20 large leaves or more depending on the farrowing space. The sow should have plenty of time to process the materials and build her nest. Our sows take 12 hours. She will shred the banana leaves. Sometimes, she is not able to do this well enough. Thus we give her banana leaves that are thoroughly dry so they are easy to shred. We may also cut the banana leaves along the length of the midrib so it is easier to shred and the tough midrib will not trap piglets.
Keep the sow in good body condition. Do not overfeed the sow. Don’t make her overly fat. If the sow is too fat and heavy, she is not agile and flexible. She cannot avoid crushing her piglets and cannot get up quickly when a piglet squeals when crushed. Crushing is also common when the disparity in size of sow and newly born piglets is very large. Thus, research shows that crushing tend to be higher with older sows/higher parity. Our sows are nearly 4 years of age and we do our best to keep them fit and agile.
Feed the sow on a regular schedule. We feed our lactating sows three times a day and we stick to this. Make sure the piglets are not in the path of the sow when you feed her, otherwise, she may step on her piglets in the excitement to eat.
Motivate sows to farrow next to the creep space. This isn’t easy and we’re trying to do this by working with the sow’s natural instincts and not working against it or by force. In a loose-farrowing system, we can’t dictate where the sow decides to build her nest and farrow. Our sows always build their nests away from the farrowing rail/creep space. The sows always want a location that is away from the gate, the feeding trough and the creep space. However, the sow often begins to nurse her piglets away from the nest 24 hours partuition. This is the time when we try to get her to nurse her piglets next to the farrowing rail/creep space. We do this by putting forage material for her to eat near the farrowing rail/creep space and by dripping water over her neck to cool her down in this location. Often, she will favour nursing at a location where she feels comfortable. When it gets too warm in one location, she will move to another.
Provide heating in the creep space for piglets. Piglets seem to avoid bright lights so a bright heating lamp may not be suitable. We have tried incandescent lamps which are not suitable. We currently have infrared lamps which are still too bright. Perhaps a green coloured infrared lamp would be suitable. In a study, piglets are supposedly attracted by green colour. Use heating lamps only when temperatures are low (below 25°C) and only in the first few days to a week of farrowing. We notice that when temperatures go down to 22°C, the piglets will use the heated creep space even with the bright infrared lamp.
Entice piglets to use the creep space. Piglets prefer to sleep in random places and they won’t even start sleeping in the creep space until they are 7 days old. We would really prefer if they used the creep space from Day 1 and avoid lying next to the mother. To get this to happen, we will need to motivate the sow to build her nest next to the creep space. In the video below, Sow Number 3 built her nest about 5 feet behind the creep space, in the corner of the pen. She has always considered this space a safe space for farrowing. We tried to entice piglets to the creep space by putting materials from the nest into the creep space. This did not work very well at all. We tried to entice the piglets by putting soil and grass in the creep space which seemed to have better results because piglets love exploring and eating soil.
Reduce heat stress. Sow housing should be well ventilated and protected from long periods of sunlight. We have switched from dry to wet feeding to see how that may reduce heat stress. We also plan to install an electric fan in the farrowing pen, which may be directed to a cool space near the farrowing rail/creep space to entice the sow to nurse her piglets in that location. ‘Impact of Smallholder Management Strategies on Sow and Piglet Condition’ is an interesting doctoral thesis that shows the importance of some low-investment strategies for improving sow and piglet health and welfare in a tropical setting.
Try to schedule farrowing in cooler months. In lowland locations in the Philippines, this would be in temperatures of 24-29°C. This is fine for sows and not overly cold for piglets. Sows have greater difficulty during the hot summer months and crushing rates are highest during these months.
Establish a positive relationship with the sow, so the sow will not be stressed or threatened when she sees you. Avoid noise, sudden movements, distress. Talk gently, don’t shout. Never hit or hurt a sow.
Treat MMA (mastatis, metritis, agalactia) ASAP. Check for mastitis which may be a reason why a sow would not nurse her piglets and easily get hurt by suckling. If mastitis is not present or cannot be treated within a few hours, grind or clip piglets’ teeth if necessary, for example, when the sow growls and refuses to nurse her piglets. The procedure must be done by an experienced animal technician. It must be done quickly and expertly. It must be done with no or very little piglet squealing. Collect the piglets and clip/grind their teeth away from the sow. Or you can let the sow out of the farrowing pen and process the piglets while she is away. In a loose-farrowing system, no other mutilation should be done – no tail cutting, ear notching or castration.
Rest and relaxation for sow, exercise for piglets. Give the sow some control over the nursing schedule so she doesn’t get irritated by piglets squealing for milk. We try to do this by letting the piglets out of the farrowing pen through an escape hatch. The piglets spend time playing and rooting in the garden outside the pen while the sow rests undisturbed. When she wants to nurse her piglets she calls them. Although this doesn’t happen most of the time, it does help to relax and calm a sow when she can rest away from her piglets. In the above video, the piglets go out into the garden while their mother relaxes in the farrowing pen.In the video below, Sow Number 3 plays in her pen while her piglets are out in the garden. Number 3 is 3 years and 4 months old and yet she likes to play. She plays like this even when the piglets are in the pen, scaring the piglets, but she tries her best not to trample on the piglets.
Understand the personality of your sow. All sows are different. Don’t blame a sow for crushing incidents. Instead, try and understand why crushing happens.
If you witness a crushing incident: Wait for a few seconds to allow the sow to hear the squeal of her piglet and get up. This is an important process that will train the sow to heed the squeals of her piglets. This also trains the piglets to avoid the sow when she is about to lie down, thus sow and piglets learn to coordinate their movements. If the sow doesn’t get up in 10-20 seconds, you may approach her gently and entice her to get up. You can call her or ask her to have some food or water, forage etc. When the sow gets up, the piglet can escape. If the piglet doesn’t move, it may be suffocating. You can revive a piglet that isn’t breathing by holding it upside down and shaking it in a downward direction and giving it several slaps on the back. Put a finger in the piglet’s mouth to clear the airway and induce breathing. Massage its chest to get it to breath. Some studies have shown that piglets crushed for several minutes can still be revived. We have revived a couple of piglets in this manner. The video below shows two piglets that survived crushing. One piglet has a limp but this became better after several days.
Breeding for Good Maternal Instincts and Understanding The Sow
Domestic sows for commercial production have been selectively bred to be prolific. While wild and native sows have a litter of only 3-6 piglets, their domestic counterparts give birth to 12-14 per litter.
If we had a choice, we would prefer that the sow produced a smaller litter of piglets with high birth weight and lower or no crushing incidents. This would probably be the sow’s choice too. We have also wondered if a sow deliberately crushed her piglets when she had too many. An interesting paper on this topic is ‘Maternal behaviour in pigs and its relation to piglet performance and survival’. Some of the interesting theories mentioned in the paper are the following:
Theory of Maternal Investment
Some sows are more responsive to the piglets’ scream than others (Hudson et al. 1991). The question is, what differs those sows from the others? Is there any explanation for this variation? The main opinion about crushing seems to be that sows crush piglets by mistake, and that some sows are more caring than others. Andersen et al. (2005) questioned this a bit by presenting their theory about reducing maternal investment. The point with reducing maternal investment is to be able to have more offspring in the future (Manning & Dawkins, 1998). Most of the fatal crushing occurred the two first days after parturition and this supports Andersen et al. (2005) theory because then the maternal investment is still on a low level. The sows that crushed piglets had generally larger litters and this also support this theory because a large litter means a larger investment (Andersen et al. 2005). If Andersen et al. (2005) theory is correct; how can killing piglets increase the sow’s fitness? Infanticide is present in various species and the causation seems to be species dependent. Female rabbits sometimes kill their young and eat them. Boyd (1985) suggest that this may be one way for the rabbits to adjust the balance of stored nutrients and litter size in relation to the capacity to obtain nutrients from the environment. But this seems not to be the case for pigs because Andersen et al. (2005) do not mention anything about sows eating their crushed piglets.
There is also a theory on sex-biased parental investment called the Trivers-Willard hypothesis. It predicts that parents will bias their sex ratio toward sons when in good condition and toward daughters when in poor condition. That daughters are more benefiting than sons during poor conditions are explained by the notion that males in poor body condition, which can be a result of poor environment, seldom gets a chance to mate (Trivers & Willard, 1979). This theory is sometimes used to explain infanticide. In a study made on wild boars they counted and sex determined fetuses in the uterine of wild boar females killed by hunting and they saw some tendency to biased litters. Small litters contained more males and large litters more females (Servanty et al., 2007). So it seems that there is a relationship between sex-ratio and litter size already early in pregnancy. If sex-ratio can be shifted already before birth it would probably be more inexpensive than provide them with nutrients during the whole pregnancy, give birth to them and then crush them. The piglets’ sex is not noted in Andersen et al. (2005) study so it is unclear if they crushed one sex more than the other.
Nest Building Theory
In a restricted environment, sows are more active during farrowing than sows kept in semi-natural environment (Thodberg et al., 2002). It could be a result of the restricted environment. A restricted sow may become stressed prior to farrowing, and continue to be so during farrowing, because she cannot perform her natural behaviour and build a suitable nest. The findings by Thodberg et al. (1999), that sows were more active prior to farrowing and less active during farrowing when given access to nest material, supports this theory. In a semi-natural environment the sow can express her natural behaviour to a much larger extent so that she might be more satisfied compared with the sows kept indoors. She have unlimited access to different kinds of nesting material so she can build a satisfying nest. If the sow doesn’t get the ability to build a nest she is satisfied with, she might not stop nesting. This is because the later phase of the nesting behaviour is triggered by feedback and external stimuli (Jensen, 1993).
The Isolation Hypothesis
Sows indoors are often kept very close to other sows. Sows living under natural conditions leave the group when they are about to farrow (Jensen, 1989) and it is likely that this behaviour has been evolutionary favoured; that it has increased the sow’s fitness in some way. The hypothesis of why the sow leaves the group is that the isolation is necessary for the piglets and the sow to learn to recognize each other and to avoid cross suckling (Jensen, 1986). One thing that may have a negative impact on the piglets’ survival is that sows kept close to each other can hear vocalizations from the other sows’ piglets. This may habituate her to the sound and way make her less attentive and responsive to the sounds that really mean something: the sounds from her own piglets. It is important that the sow react to distress calls from the piglets, otherwise she might crush them. Crushings often have underlying causes and they are interlinked. The piglet can be weakened for some reason or even already dead when the sow lies down on it. So, the sow cannot be blamed alone but her behaviour can in some cases affect the outcome. If she rises up to a sitting or standing position she may be able to save the piglet because many piglets die of suffocation (Weary et al. 1996). Because there is a genetic correlation between response to piglet distress calls and piglet mortality (Grandinson et al., 2003) it would most likely be possible to affect this trait by genetic selection.
Thodberg et al. (2002) studied maternal behaviour in sows and used animals that previously, at younger age, had been tested for behavioural reactivity. The authors suggest that the extreme sows in this test had similarities to proactive and reactive types described for rodents. These two types of coping styles differ both behaviourally and endocrinologically. In mice, proactive individuals show more active avoidance behaviour, nest-building, routine formation and less flexibility than reactive individuals. Proactive individuals get high levels of catecholamines in the blood when they are stressed, but the cortisol levels stays low. (Catecholamines cause general physiological changes that prepare the body for physical activity (fight-or-flight response); while Cortisol is one of the most widely used biomarkers to detect stress in pigs). For reactive, is it the other way around, they get high levels of cortisol and low levels of catecholamines (Koolhaas et al., 1999). Proactive and reactive coping styles have also been studied in pigs. A study by Janczak et al. (2003) could not confirm that there are different coping styles in pigs whereas Ruis et al. (2000) got results supporting that there is. Thodberg et al. (2002) found that individuals showing proactive behaviour in the behavioural reactivity tests were behaving with less flexibility when it came to nursing. The reactive individuals appeared to be more in control of the nursing behaviour. However, the authors also recorded other traits in this study that did not fit the proactive/reactive theory (Thodberg et al., 2002).
And finally, here is a potential breakthrough in reducing piglet crushing incidents. 😉 In the video below, Sow Number 3 is nursing her piglets in a standing position. Sow Auntie Brownie does this as well. The piglets are 18 days old in this video. If only the sows would do this from Day 1. However, because she was feeling so relaxed by the suckling, Sow Number 3 fell over and nearly crushed her piglets! She got up quickly and continued nursing them, then proceeded to eat. 🙂
And the work continues….
If you have experience with sows and the reduction of crushing incidents in loose-farrowing or pasture systems, we would love to hear from you. Please share your experiences with us in a comment to this post. Thank you and happy farming!
Number 3 was serviced by Pinky Boar on November 13, 2017. Her expected date of farrowing was March 8 (115 days gestation). She farrowed March 9 (116 days). Number 3 has a history of farrowing on time and not earlier. This is her third parity.
First Few Hours – March 9, 2018
Around 1AM, I heard Number 3 making grunting sounds, not desperately asking for nesting material but since she usually does not grunt at this time of the night, I suspected she will be farrowing soon (12-24 hours).
At 6:10AM, our usual feeding time, a small amount of feed was given. I saw that the dry banana leaves we gave her yesterday had been put in one corner of the pen, indicating she was already exhibiting nesting behaviour in the night, thus the grunting sounds several hours ago.
7:00AM, we gave her more dry banana leaves which she collects and starts nest-building, stopping to rest every now and then, until around 10AM.
12:00 noon, I saw a couple of piglets! Farrowing must have started at least 30 minutes earlier. Number 3 farrowed along the lower right corner of the pen near the wall, her head towards us and her back along the wall, so we couldn’t see the piglets as they come out. The piglets are only partly visible through the gaps along the pigpen wall.
12:36PM, there appears to be 2 black and white piglets and 1 brown piglet, all suckling already.
1:41PM, two hours old, first sign of piglets fighting at the teats, so Number 3 starts grunting which helps stop the piglets fighting. While grunting indicates milk flow, I think it also creates strong vibrations across the teats which calms down piglet fights.
2:05PM, a rather lively piglet has started exploring the pen, then quickly returns to the mother.
2:30PM, a piglet travels even further towards the opposite side of the pen and stays there for a while, probably to urinate or defecate.
3:30PM, about 4 hours from the onset of farrowing, Number 3 gets up to eat the afterbirth, drinks water and eats about 400 grams of feeds. We counted 9 piglets born alive.
4:00PM, Number 3 lies on her right side, instead of her left side (her farrowing side) and this resulted in a lot of piglet fighting. The fighting subsides after a while. I think because Number 3 changed her first nursing position, the piglets need time to find their teats which can result in competition for teats.
Nursing takes place every hour, and Number 3 maintained this regimen for the rest of the nursing period.
Above Video: The light brown piglet climbing over the others is Humphrey. His teat is established at the first row upper left side of the mother, parallel to Panda, but he has trouble finding and attaching to it. He remains a very active piglet, but later he was the last to outgrow his scour. The black and white piglet that is unable to attach to a teat is Blackie. She gives up easily when she is unable to find her teat. She is the weakest in the litter and died due to accidental crushing. Panda is the rightmost piglet suckling. He had developmental problems but he attaches very well to his teat and grew to become one of the biggest piglets. The light brown piglet going to the mother’s head with Humphrey is Ihid and is considered the runt in the litter. He is growing fine.
Above Video: The weakest piglet, Blackie, is the focus in this video. I notice that the weakest piglets don’t engage in play and don’t actively explore the environment. Instead, they dig their snouts into the ground persistently. This is obvious even at only 2 days of age. In my experience with pigs of various ages, this persistent behaviour almost always indicated illness.
Some Observations on Farrowing
I was worried that Number 3 would have difficulty farrowing because she has a small vulva and thus possibly, a small cervix and birth canal. Interval between piglets in previous farrowing were 30-45 minutes. However, this time, farrowing was much easier and shorter intervals (5-10 minutes) between piglets. I think it might be due to the fact that this is Number 3’s third parity and because of the addition of calcium in her diet. Calcium metabolism is also fairly good since Number 3 gets plenty of sunlight and exercise.
Above Video: Piglets at 5 weeks of age. Number 3 enjoys having her piglets and at the same time knows how to discipline them when they are fighting.
Above Video: Here, Number 3 is squeezing her way into the piglet creep space so she could eat their food. Because of this situation, we have decided to build a fenced area just outside the Piglet Escape Hatch. We call it the Piglet Restaurant where piglets can eat and drink safely, away from their mother. It is fenced to prevent ducks and chickens from eating the piglet’s food.
Some Observations on Lactation, Nursing and Sow-Piglet Interaction
Above Video: At 2-3 days of age, the piglets have discovered the Escape Hatch. They begin by exploring the soil outside. Later, they go further and eat soil and vegetation. It becomes their routine to go out and play after nursing. This gives the mother the chance to rest and relax inside the pen. Later, we built a fence around this area where the piglets can escape and eat, away from the mother.
Number 3 produced a lot of milk at farrowing. By 7 days of age, milk production became insufficient because I continued giving her only gestation feeds and the lactation feeds have not arrived. When piglets fight and ask the mother for more milk that is a sign there isn’t enough milk production. I tried to rectify the problem by giving Number 3 some papaya fruits and leaves, and by giving her lactating feeds once it became available. This solved the problem in 2-3 days.
However, because of the early scarcity in milk production, fighting among litter-mates became somewhat established and piglets also developed the habit of drinking water from the mother’s trough. Piglet behaviour is developed early on and can be difficult to change. So it is important to start with good conditions.
Number 3 tries to adjust her position during nursing so all piglets have access, except when she is too tired or too relaxed to notice there is trouble amongst piglets. Number 3 also gives special attention to weaker piglets, allowing them to access her teats or continue suckling while the others are asleep.
Above Video: 3-day old piglets fighting. This is Puzzles (black and white spots) and Brownie. These piglets are next to each other at the teats and will continue to fight at the teats until weaning. The mother disciplines pigs that fight.
Number 3 disciplines naughty piglets. When there is fighting at the teats and Number 3 gets hurt, she growls, gets up and nips the piglet that is causing trouble. She actually knows who is being naughty.
Video Above: On piglet discipline, relevant behaviour is in the first 15 seconds of this video. Piglets are 17-days old in this video. In the past several days there has been much fighting at the teats because of one or two very aggressive piglets. Notice the third piglet from the left fighting with the second piglet. Number 3 gets hurt, growls and gets up, then looks for the naughty piglet and nips her. This is how Number 3 disciplines her piglets – she actually knows who is at which teat and who is being naughty. Despite much fighting such as this, Number 3 never savaged any piglets and continued to nurse them. We don’t cut any piglets teeth.
On Crushing/Laying Over
One piglet was crushed accidentally on Day 3. This was a weak piglet, perhaps unable to nurse well on the first hour of birth. The accident was partly my fault. I gave Number 3 a small bath near the trough which motivated her to lie near the trough and nurse her piglets there. That area is a dangerous place for piglets, particularly when the mother gets up for feeding time. This was the same area where the weak piglet was crushed.
Above Video: Number 3 lies in the distance, then calls her piglets to suckle. This is a great technique, reducing risk of crushing or laying over. Piglets are 9 days old here and although Humphrey has already established attachment to his teat, he still likes humping over everybody!
Since a piglet was crushed, the rest of the litter have become more wary of the mother and they try to be more careful and alert. They actually try to avoid sleeping near the trough. The mother also discipline her piglets to keep them from going between her legs or under her teats while she is about to lie down. It is obvious that the mother is aware of the dangers of crushing/laying over. Interaction between sow and piglets is crucial for them to establish communication.
Caring for a Slow, Under-Developed Piglet
One piglet we call Panda is different from the others. He is of normal size but has a somewhat bulbous head, arched back and very slow in response and perception. Initially, he had a weak suckling reflex although he does attach tenaciously to his teat. He doesn’t have the same gait as his siblings and has difficulty getting up.
Above Video: Here is Panda at 10 days of age. He has a somewhat bulbous head, a rigid gait, an arched back, and he doesn’t run around as actively as the others.
Above Video: Here, Panda has difficulty getting up while everyone else is already drinking milk!
Above Video: While piglets actively explore the garden, Panda seems to have difficulty. However, the excitement of the outdoors kept his spirits high and was daily motivated to get better. In the next couple of days, Panda progressively became better, catching up fast on his litter-mates.
Panda received Iron Drops like all his litter-mates. We don’t intervene during nursing and leave him to find his teat and develop good suckling reflex. Drinking water is provided for all piglets in an outside creep-space we call the “Piglet Restaurant.” All piglets are allowed to go out into the garden and eat soil, vegetation. Panda was the weakest but he always looked forward to going out into the garden. The outdoor exercise and abundance of soil and vegetation had a strong positive psychological influence on Panda. In fact, despite his ‘disability’, Panda was quite fierce in defending his teat from the other piglets. In 2-3 weeks, Panda is nearly as active as his litter-mates.
Above Video: 20 days old. Humphrey is a very playful piglet since the beginning. He is parallel to Panda at the teats. Early on, he developed the habit of humping Panda (and other litter-mates), thus his name. In this video, he harasses Panda and Panda squeals. The mother hears this and calls. Humphrey hears the mother and stops, to Panda’s relief, and pretends to have not done nothing wrong by rooting the ground.
Above Video: Here, the piglets are 16 days old, enjoying the garden. Panda is doing much better here and being able to go out into the garden and play has given him great psychological motivation to get better.
Some Observations on Post-Weaning
We separated Number 3 from her litter when the piglets were 45 days of age. All the piglets remained active and playful and eat well. Scour began to set in at Day 2-3 of weaning and remained up to 6 days so I decided to intervene with probiotics. The scour is grey, watery, projectile of various degrees. All piglets remain active and eat well. Piglets were also given green banana leaves. There was some improvement but scour remained. So by Day 10 I decided to give Apralyte treatment, an anti-scour formula, for 5 days.
Day 2 of anti-scour treatment, piglet scours are thicker and not as watery as before and the appetite of the piglets increased immediately. Day 3 of anti-scour treatment, the piglets began to get bigger as well. By Day 4-5, piglets are all back to normal, except for Humphrey who was the last to get rid of his scour completely.
Next time, I must include probiotics in sow/piglet water at least a week before weaning. Although the pigpen has been sprayed with Lactic Acid Bacteria solution, that didn’t seem sufficient. This batch of piglets also had less green forage because of the early provision of piglet crumble feed. We have had better cases in the past wherein piglets did not develop scouring as bad as this and they did not receive any piglet booster or crumble feed. I think next time I should implement early addition of probiotics in piglet diet before, the abundance of green forage and the late addition of any protein-rich feed (piglet booster, crumble, etc) in their diet.
Although we can look after piglets after they are born, I am getting more interested in how to make the piglets healthier while still inside the mother’s womb. Iron deficiency is one of the biggest hurdles. While I am still studying how adjustments to the mother’s diet may help, it is also possible to provide Iron rich forage and soil that piglets can nibble on as early as the first 3 days of life. The pigpen floor has more sawdust than soil, so while the Piglet Escape Hatch into the garden is crucial, I will need to put some clean soil into the pen for the piglets.
Some Observations on Extended Lactation/Nursing (up to 3 months)
Above Video: This is perhaps somewhat embarrassing but Ihid does not care! Here he is still suckling at nearly 9 weeks of age!
We allowed the runt Ihid to stay with Number 3 until he was 90 days of age. Ihid continued to suckle and the mother allowed him to do so but less frequently. Because Ihid was unable to eat well in competition with his mother he has not put on as much weight as his siblings. He developed no scouring.
However, after weaning, Ihid developed scouring after 3 days, so Apralyte treatment was given by day 5, for 3 days. Improvement is observed quickly. An acidifier, citric acid, is also added to Ihid’s water. This is now also given regularly to the adult pigs, ducks and chickens, to lower their gut ph, improve digestion, and reduce effluent. Less messy effluent also means minimized odor and easier management.
Above Video: Ihid the Runt finally weaned at nearly 3 months of age. He misses his mom. We are deciding to keep 2 piglets next time so the pigs don’t become too lonely.
Piglet Weights at Post-Weaning (55 days): 25-16 kilos. The females weigh less than the males. Panda weighed 22 kilos.
Four piglets were sold to two neighbours and three piglets were sold to an orphanage in Dauis. We keep Ihid the Runt. Although we have done this many times before, I still miss the piglets every time! I love each and every single one of them! 🙂