Claw lesions and lameness lead to the impairment of animal welfare, health and longevity of sows, a challenge the pork industry continues to battle.
“Sow lameness has a remarkable effect indirectly on a sow farm’s reproductive efficiency,” says Jason Ross, who serves as the chair of the Department of Animal Science at Iowa State University. “Sow lameness is a primary reason sows leave the herd early and as a result, compromises pigs weaned per sow per year.”
Recent studies by Zinpro have focused on quantifying the impact of lameness and claw lesions on reproduction and developing assessment tools to help producers make changes on a per-herd basis.
“Reproduction is the consequence of having a healthy sow, and to have a healthy sow, it is important to have all the organs and systems working correctly,” says Ton Kramer, business manager for Zinpro in South America.
The legs and the feet create the interaction between the animal and the environment, he explains.
“It’s important to have healthy feet and legs to allow the animal to manifest behaviors — going to feed, looking for water, reproducing — as best as possible,” Kramer says.
To better understand the prevalence and severity of claw lesions on farms, Zinpro created a database with more than 30,000 sows and recently started collecting performance data on total born and born alive piglets per sow.
What is the Severity of Sow Claw Lesions?
Using a dataset of more than 6,000 sows, researchers assessed sow’s feet, assigned lesion scores during lactation, and recorded reproduction performance.
“The research showed the animals that have higher severity of the lesions, especially due to overgrowth and erosion or white line lesions, are the animals that had the lowest number of piglets born alive and the highest stillbirth rate,” Kramer says.
The data showed 40% of sows were in the high or severe lesions cluster. This means these sows had 5% fewer piglets born alive, which can have a big effect on the economic sustainability of a production system, Kramer says.
Another study sought to establish a standardized method for evaluating claw lesions, which is crucial for recognizing, treating and preventing these disorders in sows.
In that study, a total of 3,583 sows from 20 Brazilian sow herds, were randomly selected and scored for lesions on the hind legs after parturition. In addition, 845 finishing pigs were randomly selected from a population of 6,000 slaughter pigs and scored for lesions on the left hind leg during pork processing.
Lesion scores were based on a four-point scale evaluating heel overgrowth and erosions, heel-sole crack, separation along the white line, horizontal and vertical wall cracks, overgrown toes and torn claws, according to Zinpro. A lesion index (L-Index) was calculated as a sum of the higher scores from each lesion, per sow or finishing pig.
Nutrition from the Ground Up
When it comes to nutrition, physiologically the most important function is keeping an animal alive and nutrients are first portioned to the main organs, Kramer says.
“When we think about ligaments, skin, mucosa and the claws, they are not the most important organs to keep an animal alive, so in situations of stress, they will not receive the amount of nutrients needed to make them better quality,” he explains.
If the animal has good quality of claws, the animal is likely to be in good health. Kramer notes the animal will be able to walk well, get food and water easier and maintain life better. Reproduction will be better, too.
“If you consider the inflammation, pain and stress related with the claw lesions, the animal will not perform as well because the inflammation that is related with the lesions will change other hormones that affect reproduction,” Kramer says.
Common Lesions Found in Sow Herds
Two lesions – heel overgrowth and erosion and white line – usually occur in different phases of life.
“Heel overgrowth and erosion increases on prevalence and severity during the reproductive life because as the sow grows, the weight bearing on the heels will increase,” Kramer says.
White line lesions are related more with young animals.
“We see gilts developing faster and faster and this is affecting tissue formation,” Kramer says. “The claws are not mature enough to support all the challenges on the farm — the movement of the animals, the moisture in the air, and the slatted floor environment.”
Kramer notes with pen gestation, there is more animal interaction.
“There are more fights happening as animals interact in a higher frequency, generating lesions and damaging the claw, therefore white line lesions are much more frequent on younger gilts than older animals,” he says.
Lesion Lessons
Kramer says it’s important to know if lesions are a problem in your herd. He recommends producers perform two assessments a year to understand claw health and the type of lesions present, as well as the severity of lesions in the animals.
“This is the first point to understand what is happening in the herd,” he says. “It is also important to understand flooring, handling and management, then nutrition. Assessing these will bring opportunities to understand what is in the feed, what is in the water that the animals are consuming, allowing producers to make the adjustments.”
Understanding the factors that affect claw lesions, including the environment, stress, genetics and nutrition, provides producers with opportunities to make adaptations.
“Any condition of stress will result in a change of the nutrient partitioning and inflammation will change the demands of nutrients,” he says. “Making the movement, transport and interaction of the animals as calm as possible will reduce the possibility of generating these lesions.”
Modern swine genetics have been selected for higher production and with that comes higher nutrition demands, Kramer says.
“Sows are producing 35 to 40 piglets per sow per year,” Kramer says. “This results in a higher demand of nutrients. Because of this, sows are not able to obtain all these nutrients to build a stronger claw. With proper nutrition, we can increase the possibility of having a healthier animal in the herd, or a healthier herd, and this will help to allow the animal to manifest their genetic productivity.”
