Sharing knowledge at international conference on ruminant lameness

Chile is a country as diverse as it is long and narrow. It stretches more than 2,650 miles from the hot, arid deserts of the Atacama in the north, down through the lush wine, fruit and dairy regions, and through the fjords to the vast pastures of Patagonia.

Valdivia is one of the oldest cities in the southern hemisphere and is found in the beautiful lakes region of southern Chile.

The Universidad Austral de Chile in Valdivia hosted the 10th International Conference on Lameness in Ruminants, providing the opportunity to learn more about lameness and Chile as a country – and how agriculture has played a fundamental role in its past and will in its future.

Chilean dairy industry

Home to 18 million people and half a million dairy cows, Chile was a net importer of dairy produce until 2004. However, the past decade has seen a move towards the country becoming a major player in the global market.

About 16,000 dairy farms exist in the country, employing nearly 40,000 people. More than 85% of Chile’s dairy cows are found on pasture-based systems in the south of the country, accounting for the seasonality of production. In these regions, rainfall is more consistent than in other parts of the country; 1,500mm to 2,000mm falls per year.

In the central and northern regions, there has been a trend towards housing cattle for part of the year to avoid pasture damage, although few, if any, herds are housed all year.

Chile is divided into regions and dairy farming predominates in two southern regions – region XIV and region X (Figure 1). Region XIV mainly consists of family farms, with an average herd size of 100 cows and lactation yield of more than 4,500 litres. In contrast, region X has seen the development of larger, corporate-run farms where average herd size is closer to 1,000 cows and yields much higher at more than 7,500 litres (Chesterton, 2015).

In 2014, the Chilean dairy industry produced 2,149 million litres of milk at an average farm gate price of 300 Chilean pesos per litre (about 27p), a decrease in price of 3.7% on the previous year despite similar production levels. Available figures for 2015 show a large decrease in production at the start of the year, mainly down to the impact of drought affecting grass growth during the early part of the year (Figure 2).

Consumer patterns

It is hard, if not impossible, to find fresh milk in a Chilean supermarket. Instead, UHT milk and milk powder is sold.

A large demand for milk powder still exists because, in some parts of the country, families do not have refrigerators in which to keep UHT milk fresh after opening.

However, over recent years, consumption of milk powder has been falling and UHT rising. Despite this change in consumer buying, milk powder production will remain an important product of the dairy industry.

More than 75 million litres of milk are used in the production of whole milk powder and government food programmes use a significant proportion. In the winter months, when production is low, milk powder is reconstituted to produce fluid milk, which is then used to produce dairy products that have a constant demand throughout the year.

Thanks to the thriving wine industry, Chile has also seen a big increase in the consumption of cheese – more than 85 million litres of milk finds its way into cheese each year. In 2009, 5.8kg per capita was consumed, compared to 9kg in 2014. By comparison, the UK consumes 11.6kg and the US 15.5kg per capita (CLAL).

Lameness in Chile’s dairy cattle

Like many countries around the world, lameness is a serious welfare issue on many Chilean dairy farms with a reported average lameness prevalence of 26% (range 8.2% to 45.1%; Chesterton, 2015).

At the conference, Neil Chesterton shared his experiences of consulting in Chile over the past four years, and how the causes and risk factors for lameness in Chile compared to his home country of New Zealand.

It was interesting to note not only Chile benefited from his input, but also New Zealand, highlighting the importance of international involvement and discussions on this worldwide problem.

The predominant causes of lameness in Chile’s pasture-based systems are similar to those seen in other parts of the world, with white line disease predominating (62% of lesions). Sole injury accounted for one in five cases, all pointing towards a common cause of trauma to the hoof from cow tracks and concrete yards.

Due to the pasture-based systems, it is common for cows to walk long distances each day, with paddocks being up to 1.5km from the parlour and, in some instances, 3km – exacerbating any shortcomings in track design and management.

Due to the undulating land in the main dairy regions, the tracks are not flat, therefore increasing the level of trauma to the hoof. When combined with the fact tracks tend to be too narrow for the size of the herd, and persistent high rainfall leads to poaching of the tracks and softening of the hooves, it creates the perfect situation for lameness.

The link between poor stockmanship and lameness has been clearly identified in many countries. In New Zealand, in particular, the use of a quad bike to herd cows has been associated with an increased risk of lameness. While quad bikes are not common in Chile, horses are (Figure 3). They may not be able to reach the speeds of quad bikes, but horses naturally walk faster than cows and there is a risk of the horseman rushing cows down the tracks, leading to compaction of the herd and an inability for the cows to select the best path to walk.

Given space and time, cows walk with their heads looking at the ground so they can determine where to place their front feet and avoid stones or holes. When rushed or compacted, they have to raise their heads over the backs of other cows, losing their ability to determine where they place their feet. In addition, more pressure is placed on the feet when the cows are having to force their way into the rest of the herd when not walking at their natural pace.

The type of soil found in Chile further exacerbates the risk factors for lameness. Chile has a very volcanic landscape, with its volcanoes forming part of the “ring of fire” that circles the Pacific Ocean. They are also far from dormant, with the most recent eruption just north of Valdivia in May 2015 when Villarrica erupted.

The volcanic gravel left behind by centuries of eruptions is abrasive to the horn of the cow’s foot, increasing the wear rate to the sole and exposing the underlying corium to traumatic damage (Figure 4). While using a less abrasive material on the walking surface is preferable, this is difficult to source in Chile and presents a problem for future prevention strategies.

While the tracks create risk factors for lameness, so does the concrete of the collecting yard and milking parlour. When pasture or tracks are poached and churned up, there is a risk of cows bringing gravel and stones on to the concrete, which can then lead to trauma to the soles or punctures when soles are thin.

Stockmanship in the collecting yard has also been recognised as a common cause of stress in Chilean herds and highlights the need for training in stress-free stockmanship, as is the case in numerous countries.

Conclusion

Chile is a unique country, with a diverse range of climates allowing it to produce a wide range of quality food products. However, despite its niche qualities, it shares much common ground with other countries when it comes to tackling lameness.

Chile has clearly benefited from collaboration with New Zealand, but the benefit has not just been one-way; as much can be learned from similarities between countries as from differences. Thus, the importance of international collaboration and sharing knowledge remains key in tackling lameness – not only in the UK, but worldwide.

I look forward to the 2017 conference in Munich.