HOW OUR PIGS SEE THE WORLD

Photo: Mr & Mrs S Hricko

The Pigs Eyesight

The OSBPG Charity is always looking to investigate the wonders of pigs and this topic is by no means any different as we look to the topic of the vision of Pigs.

Pigs possess dichromatic vision, enabling them to perceive the world in blue, green, and various shades of red. However, unlike humans, they are unable to distinguish the millions of colour variations due to the absence of certain large wavelength cones in their vision.

In practical terms, this means that while pigs can identify all variations of blue and green, they lack the ability to distinguish between different shades of red with varying wavelengths.

It’s important to note that it is not only Oxford Sandy and Black Pigs that are not colour blind it is the same with all pigs; they see the world similarly to humans but in solid, distinct colours.

The Colour Vision of Pigs

Pigs can see blue, green, and red colours but are sensitive to different wavelengths as compared to humans. They are dichromatic animals. It means the cones in their eyes are only primarily sensitive to small and medium wavelength colours, i.e., blue and green.

Simultaneously, humans are trichromatic; hence the cones in our eyes can perceive small, medium, and prominent wavelength colours, i.e., blue, greenand red. However, according to a recent study by PigVision Institute, it is unveiled that pigs’ eyes are least sensitive to red colour up to 650 nm.

It demonstrates that there is a slight possibility that pigs can sense a small portion of red colour.  You will see the picture below, which show how we and pigs acknowledge different colours.

As justified by the recent studies, pigs’ eyesight can perceive green and blue colours at peak wavelength sensitivity at 439 nm (blue colour) and 556 nm (green colour).

Studies have shown that photoreceptors in a pig’s eye can just about recognise the colour of red, at a reading of under 650 nm.  In comparison, humans can see every shade of colour formed under the visible spectrum ranging from 380 nm to 720 nm.

The Way Pigs See the World

Pigs are not colour-blind and can see the world in colour. They are near-sighted and have a wide range of visual fields with a little bit of depth perception.  However, their vision is not as clear as ours.  It is estimated that the optical power of the pig eye is far much greater than the optical power of humans. Therefore, at far distance their vision will sense a duller outlook.

Also, being dichromatic, the colour perception of the pigs is limited to the blue-green shades. Additionally, their photoreceptors identify the colour red vaguely.  You will see from the images on the right, how pigs see the world compared to us.

It is said that pigs see objects as solid colours with dull vision. For example, pigs may see blue sky but cannot identify clouds and rainbows because of being near-sighted.

It has been mentioned before, here on the OSBPG Charity, that to help our pigs with feeling comfortable with their surroundings using solid colours like red, green, and blue for the nearby objects so that pigs can easily distinguish them in the form of water buckets and/or feeding vessels or enrichment toys will be very welcomed.

Apart from the vision, pigs have really good ears and noses. They can sense the world a lot more through sound and smell. Most of the time, they rely on their ears and nose for navigation and surroundings rather than the vision.

Also, their nostrils are sensitive, and through them, they can recognize their owners. Pigs’ vision is indeed poor compared to us, but if we compare their eyesight with say, cattle, they can see a lot better.

Do Pigs Have Night Vision

Pigs cannot see in the dark. Like nocturnal animals, they do not have a thin layer of reflective tissue on the back of their retina called tapetum lucidum. Pigs are diurnal and love to take rest at night. Also, their eyes evolved with more cones than rods that help them differentiate many colours rather than the ability of night vision.

Having fewer rods in their eyes makes it strenuous for pigs to identify the shapes of nearby objects even in the moonlight. Their vision is the same as humans at night. Humans also have very few rods in their eyes; that’s why we are not able to see anything in the dark.

There are two types of photoreceptors in the retina:  cones and rods.

Cones are responsible for colour vision, and rods help to sense the light. Both the human and pig eyesight are concentrated towards cones.

Should the need arise to move during the night, pigs will rely on their sense of smell and sound.

The Pigs Eyesight

Pigs have poor eyesight compared to humans, but they have an average vision in contrast to other animals. It primarily depends on which animal we are comparing them to.

Pigs are dichromats, and their eyes have cones that qualify them to distinguish mainly blue-green colours. Also, they are near-sighted; still, they can see up to 300 feet which is far better than an elephant. Not only the sight, but they can also hear from far distances.

In summary, pigs indeed have functional vision, but when it comes to colour perception and clarity, their visual capabilities fall short in comparison to humans.

Pig Vision vs Human Vision

Pig Vision

  • Have a dichromatic vision and can see blue and green colours at best.
  • Doesn’t have night vision
  • Can see up to 90 meters

Human Vision

  • Have a dichromatic vision and can see blue, green, and red colours at best
  • Doesn’t have night vision
  • Can see up to 3 miles
Photo: Mr & Mrs G Hogg

The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190469) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

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Piglet Observation – Part VII

Economic Considerations Regarding Low Birth Weight Pigs

As we know, and have experienced ourselves as we observe our Oxford Sandy and Black (OSB) low birth weight pigs, they can thrive when managed and nourished correctly. With meticulous care, these OSB piglets can achieve enhanced growth rates and therefore reduce pre-weaning mortality rates.

The economic implications of raising Oxford Sandy and Black low birth weight pigs can hinge on these few factors:

  1. Feed Efficiency: Their capacity to efficiently convert feed into growth.
  2. Production Variation Costs: Expenses associated with managing variation throughout the production process.
  3. Market Conditions: The prevailing prices of pigs and feed in the current market.

These factors collectively determine the economic viability of rearing low birth weight pigs, and with the right strategies, their performance can yield positive results.

You can also tune in to the OSBPG Podcast HERE and listen to leading pig nutritionist discuss pig feed and nutrition. Whilst there subscribe to the OSBPG Podcast and be apart of engaging discussions.


The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190469) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

Piglet Observation – Part VI

Enhancing Nutrition for Improved Piglet Growth

Instead of increasing feed levels, it’s worth considering an improvement in nutrition. Selecting the right starter feed regime is vital to minimise the growth slowdown that our Oxford Sandy and Black (OSB) piglets may experience during the transition from liquid to solid feed.

Feeding a high-quality starter diet, supplemented with extra feed (matching the last diet of the starter regime), can enhance the performance of low birth weight OSB piglets up to 10 weeks of age. This approach can result in similar nursery exit weights for both low birth weight and normal birth weight pigs.

However, it is important to note that feeding a high-quality diet is less effective when introduced at nine weeks of age, indicating a critical intervention window.

Research indicates that not only do low birth weight pigs benefit from an improved dietary regime, but it is also cost-effective for producers. This approach yields a higher return per pig compared to a standard commercial regime, which has a lower margin over feed cost. For normal birth weight pigs, the standard commercial feed regime remains the most economical choice with the greatest margin over feed cost.

At weaning, separating OSB low birth weight pigs allows for selective feeding with an improved regime, as heavier OSB pigs are better suited for a standard commercial diet.

Further research reveals that nutritional treatments at different stages can impact outcomes such as:

  • Specialised diets introduced at weaning can enhance performance throughout the nursery phase and are more cost-effective than using a standard commercial regime.
  • Offering supplementary milk doesn’t significantly improve the performance of low birth weight piglets, but it does reduce birth weight variation in mixed litters.
  • Low birth weight pigs may not experience substantial benefits from a diet higher in amino acids and energy when fed from nine weeks of age.

The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190469) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

Piglet Observation – Part V

Pre-weaning care of the Oxford Sandy and Black Piglet

Creating a non-competitive environment for your Oxford Sandy and Black piglet during the early stages of life is crucial for the smaller piglets, as previously explained in “Piglet Observation Part IV“. This environment can be established through cross-fostering.

Supplemental milk, such as sow replacement milk or goat’s milk, can effectively reduce the variation in birth weights, ensuring a more consistent growth to slaughter weight.

By combining these two management techniques, we can effectively control costs, rather than providing supplemental milk to a larger number of litters unnecessarily.


The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190469) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

Piglet Observation – Part IV

Photo: Lydia Johnston

Cross- Fostering

When dealing with large litters and you have simultaneous farrowings, there may be an opportunity to implement a fostering procedure, transferring your Oxford Sandy and Black piglets from a larger farrowing to a smaller farrowing. This practice can be of benefit as well as ensuring the welfare of sow and piglets which begins with careful observation of the piglets.

Identify those piglets that show signs of lethargy and lacklustre. These observations will serve as indicators for taking action, possibly including the decision to foster the struggling piglet and at the same time provide essential sustenance such as electrolytes or additional milk.

Cross-fostering your low birth weight Oxford Sandy and Black piglets with littermates of similar weight can significantly improve their daily weight and overall health with the added bonus of high expectations for pre-weaning performance.

We are aware that smaller piglets competing with their larger siblings are at a disadvantage. Therefore, whenever possible, it is advisable to create foster litters consisting of the smallest piglets born on a given farrowing day. It is essential to introduce these small piglets to a sow that is in her early stages of motherhood, preferably on her first or second litter. Sows in their second year, for instance, tend to have smaller teats that are better suited for the small mouths of these piglets. This thoughtful approach can greatly benefit the piglets’ growth and overall well-being of the Oxford Sandy and Black Pig.

You might discover our blog titled “Piglet/Weaner – Being Prepared” to be a valuable resource for additional guidance and assistance.


The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190469) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

Piglet Observation – Part III

Photo: Mrs H Ellaway

Selection for Breeding and Observational approaches for the Newborn

Selection for Breeding

Among us, some maintain a closed herd, while others do not, often due to the practicality of keeping two sows not justifying the presence of a boar. In such cases, the option of hiring a boar becomes viable. Regardless of the approach, prioritising biosecurity remains crucial. Should hiring a boar is your preference, ensure you know the boar’s recent history; when was the boar last hired out, his health plan (wormed, vaccinated for ery/parvo) and, of course, ensure that the boars’ size suits your sow or gilt.

When selecting Oxford Sandy and Black pig (OSB) breeding stock, choose from OSB sows and gilts that have consistently produced robust litters. This indicates their strong placental efficiency, which ensures optimal oxygen and nutrition exchange therein. Furthermore, each breed possesses distinct attributes that are essential for going forward for breeding and advancing our breed’s quality. To better understand these attributes, explore the Oxford Sandy and Black Pig breed conformation HERE

Piglet Observation Approach

Being present during the farrowing process is not only exciting but also immensely helpful. It allows you to monitor various critical aspects, starting from the moment the OSB sow/gilt begins farrowing until the last piglet is born, and you witness the completion of the farrowing process with the passing of the two afterbirths. Additionally, you can ensure that every piglet receives its crucial first dose of colostrum. It is worth noting that colostrum declines approximately six hours after the onset of farrowing.

Your presence enables you to assist vulnerable piglets in accessing teats ensuring they receive nourishment without difficulties.

By closely monitoring the farrowing process, you can also promptly identify any signs of ill health among the piglets and follow the prescribed veterinary protocols for treatment. Moreover, you can verify that the piglets are positioned either on or under a heat source and not heaped up on top of each other which will indicate that they are cold. Bear in mind that the piglet has no brown fat (used by mammals to generate heat quickly) so the piglet cannot use fat to generate heat in cold conditions. Therefore, piglets require environmental temperatures of 34°C or more for the single new born piglet, or 25-30°C or more for the piglet able to huddle in order to maintain body temperature.


The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190469) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

PIGLET OBSERVATION – Part II

Photo: In pig gilt with 11 days to go. Francesca an Oxford Sandy and Black Pig Gilt photo taken on 22 January 2023 farrowed on 2 February 2023.

Enhancing the In-pig Sow Nutrition

Although the last month of pregnancy is the period when the main growth rate of the foetus takes shape, we, Oxford Sandy and Black Pig keepers must take into consideration the whole of the gestation period to take advantage of the opportunity to influence birth weights.

Direct Your Attention Beyond the Final Third of Gestation: Emphasis is more than just the last third of gestation, as this period witnesses foetal growth spurts and an opportunity to influence birth weight. Elevate nutrient intake for sows starting from day 80 of gestation to positively impact birth weight. Notably, between days 90 and 115, piglet growth rate increases significantly.

Evaluate Feeding Regime for the Oxford Sandy and Black Gilts: Carefully consider the feeding plan for your breeding gilts. Overfeeding them during the initial stages of gestation can yield both short and long-term effects. The extra feed might be directed towards the gilts’ reserves rather than the developing foetus. This practice could lead to the birth of small piglets and overweight gilts. Once a gilt accumulates excess fat, her productivity might diminish.

Remember it is worth discussing feeding options with your feed nutritionist/feed merchant.

Photo: In pig gilt with 12 days to go. Francesca an Oxford Sandy and Black Pig Gilt photo taken on 22 January 2023


The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190463) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

PIGLET OBSERVATION – Part I

Photo: Mrs R Ford


As we witness the wonderful farrowings with the anticipation of more to come, I thought it a perfect opportunity to delve into the different phases of piglet observation and care this week.

We know that recognising those piglets smaller than their littermates often exhibit delayed growth and require additional attention, and as such the following protocols may aid us to minimise the weight disparity between lighter piglets and their larger siblings.

Investigation of various factors affecting birth weight, with the aim of enhancing the postnatal performance of underweight piglets, has resulted in the following findings.

As most of us have witnessed, a common occurrence is litters with diverse birth weights. These variations tend to increase, with an overall trend toward smaller piglets, when the number born alive is higher. There is no need for alarm; entire litters comprised solely of small piglets do not necessarily indicate an issue, as these piglets can still be viable. With the right conditions, low birth weight pigs can catch up in growth to their normal birth weight counterparts. Nonetheless, early intervention remains crucial.

The prospect of piglet survival rates are low if their weight falls below 1 kg. If possible, try to weigh and gauge the number of piglets below 1kg, document the weights to enable to recognise the developments which will help you to offer extra assistance in their development.

Challenges During Foetal Development

  • Poor foetus and reduced growth of piglets can be identified as early as 30 days of gestation
  • Low birth weight can be a result of an inefficiency of the placenta to transfer nutrients to the foetuses rather than uterine capacity – ensure gilt is not younger than 12 months for service
  • Oxygen Deprivation influences the Critical Factor in Foetal Growth, Central Nervous System Impact, and Survival of Piglets
  • Some piglets may be petite but exhibit excellent vitality and favourable postnatal behaviours, such as rapid suckling, which significantly contributes to their survival.
  • Piglets that are both undersized and weak, which can be indicative of oxygen deprivation, face a significant disadvantage
  • It’s important to highlight that the maternal genotype plays a significant role in determining placental efficiency and, consequently, foetal weight, while the potential for growth and size is influenced by the sire line.

The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190463) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed

THIN SOW SYNDROME

Some of us have experienced our sows and gilts as being very drawn during and after feeding their piglets. The causes have been diagnosed as inadequate feed during lactation, farrowing house being too hot or is due to underfeeding during pregnancy. This effects weight loss and anoestrus (poor return to season).

Causes

The condition results classically from a combination of parasitism – one organism (called parasite) benefits at the expense of another organism usually of different species (worms or mange), low environmental temperatures and inadequate feed intake, particularly during lactation. Weight loss at this time may never be regained. Parasitism is less important when therapy is routinely carried out. In outdoor pig populations, low environmental temperatures are important.

Outdoor sows require at least 200 kg more feed per sow per year than indoor animals. Sow that are kept indoors during the winter cold months should be kept at 22°C and sows in moderate condition at 21°C. Lower temperatures may be tolerated in the presence of bedding. Temperatures below this require extra feed to maintain sow weight gain in gestation.

Feed intake is the most important cause. Feed intake may be affected by bullying, disease, a high environmental temperature in the farrowing accommodation, or an over fat condition at farrowing. Sows should be in condition score 3/4 or 6/10 (fat depth at P2 16-20 mm) at farrowing, which may fall to condition score 2-2.5/4 or 4/10 (fat depth P2 12 mm) after lactation. Unless these criteria are met, total weaning weight of the litter will be reduced, return to oestrus will be delayed and egg numbers will be reduced to give small subsequent litters.

Clinical signs

In extreme cases, being abnormally thin or weak may occur in 30-90% of sows and boars in a herd, associated with hypothermia 36.5-38°C (97-100°F), depraved appetites, restlessness, apathy, and later, difficulty in rising. The skin may be dirty and greasy and there may be surface abrasions. As the condition progresses, failure to return to oestrus and permanent infertility may occur.

Where accurate individual feeding to condition is not practised and bullying occurs, individual animals in a group can be clinically affected. Less than optimal condition are frequently found in winter where temperature control is not practised. Suboptimal condition or even thin sows may be found during the recovery period from disease such as influenza and may be more extreme in lean breeds. Clinical signs of suboptimal condition include increased weaning to service intervals, small litters and low weaning weights. Piglets of sows in suboptimal condition may be restless and demand milk more frequently.

Thin sows may be identified by observation and systematic condition scoring of the herd. Ultrasound is particularly useful for quantitative measurement as scoring is more difficult in older animals due to their conformation. As sows should gain at least 12.5 kg body weight between parities, regular weighing can identify animals in sub-optimal condition. Pressure sores in sows at weaning also indicate poor condition.

Where gilt condition and nutrition in lactation is inadequate, the second litter is the same size or smaller than the first, and low number born may reflect overall sow condition at service. Extended weaning to service intervals and low weaning weights may be due to poor body condition. The causes of poor sow condition should be established. It should be established that feed of adequate quantity and nutrient density is being supplied to each individual especially during lactation and until implantation 10-14 days after service. Parasitism can be ruled out by inspection, by sampling for mange and faecal sampling (which some of you do) for worm eggs and coccidia. The influence of disease may be established by inspection, clinical examination or consultation of the recent history of the herd of the animals concerned.

Treatment and prevention

There is no treatment. The effects of thin sows on litter weaning weights can be reduced by supplementary feeding of the litter, whereby some of us have supplemented with sow replacement milk in the earlier days. The effects on numbers born may be reduced when sows or gilts are in poor condition by delaying service until the next oestrus. Ensure that adequate quantities of food of the correct nutrient density are given to all affected animals and that individual feeding is possible. Environmental temperatures should be restored to normal and anthelminthic or mange treatment should be considered.

Adequate feed intake during lactation and early pregnancy should maintain the weight of the sow and increase it by 10-15 kg between litters by increasing the energy content of lactating rations with fat or feeding three times daily during lactation. It may be necessary to weigh sows after weaning (for those of you that do not have scales please may I remind you that we have a “calculate the live weight” in the OSBPG tools section of our website) in order to ensure that adequate weight gain has occurred between lactations, to assign them to groups for feeding at an appropriate level through pregnancy or to feed individually to condition.

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THE SIGNIFICANT DISEASES CHARTER

Photo: Mrs K Green-Smith

Are You Signed Up?

AHDB have been running this charter to safeguard our pigs in the UK for many years. Whether you have 2 pet pigs or a breeding herd or a keeper bringing on weaners for meat production you will benefit from this important tool.

By signing up you will be alerted by text or email of a disease outbreak in or around your area the alert will warn you of Swine Dysentery or Porcine Epidemic Diarrhoea virus (PEDv).

What to do next

You can sign up through your account PigHub or by emailing Pig.Health@ahdb.org.uk

More information about how to access PigHub can be found HERE.

Take a couple of minutes to check you’re registered next time you log into Pig Hub (its the same password and user name as your eAML2)


The Oxford Sandy and Black Pig Group is UK’s only pig breed that is a registered charity in England & Wales (1190463) and Scotland (SCO52662). We are creating a better future for our breed, the bloodlines and its breeding potential together with our Independent Pork Producers, Breeders and Keepers. Please consider clicking our donate button so we may continue to look after our breed and our supporters.

Follow us on Facebook and see how we support, help and inspire individuals about our rare breed