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0109 PD: Can dairy production be both economically and environmentally sustainable?

Jude Capper Published on 23 December 2008

It’s not often you see the words sustainability and profitability in the same sentence.

The most commonly heard view is that sustainable agriculture refers to low input-low output systems that are less concerned with maximizing production and more reminiscent of historical agriculture, with management practices similar to those used 40 or 50 years ago. This often leads to confusion and conflict as to what sustainability means in the context of the modern dairy system.

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To evaluate the true sustainability of agricultural systems, we need to consider a triangle with three sides: economic viability, environmental impact and social responsibility. If we have a system or practice that significantly reduces the carbon footprint of dairying but is prohibitively expensive to implement or a management practice that allows us to produce milk more profitably but that is unacceptable to the consumer, we have huge challenges to overcome.

However, this also provides us with opportunities for education both within the industry and by outreach to the retailer and consumer. One of the most often-heard consumer misconceptions is that everything was better in the ‘good old days’ of the 1940s and 50s.

To see just how far we’ve come, let’s compare modern ‘factory farming’ to milk production in 1944 – the peak year for dairy cows (25.6 million head) in the U.S.

Back then the average herd contained six cows, each yielding 4,572 pounds per year and fed a pasture-based diet. Antibiotics, artificial hormones and inorganic fertilizers weren’t yet used, and A.I. was only just becoming available as a breeding technique.

This fits perfectly with the consumer ideal of traditional, small-scale, local food production and the perception that there were no environmental, economic or social concerns in the ‘good old days’.

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However, total 1944 milk production was 117 billion pounds; whereas in 2007 we produced 59 percent more milk (186 billion pounds) from 64 percent fewer cows (9.2 million).

This increase in productive efficiency (milk output per unit of resource input) has been achieved by advances in nutrition, genetics, management and welfare that allow us to understand and care for cows in modern systems far better than we did in the past. Improving productive efficiency by spreading the fixed costs over more units of production is a concept that’s extremely familiar to accountants and factory managers.

This process also occurs during milk production, albeit in a slightly different way, as although cows can be thought of as ‘milk-production machines,’ there are two vital differences.

Firstly, factory-based machines only consume energy when they’re being used – at the end of the day they can be turned off. By contrast, cows require nutrients for maintenance regardless of whether or not they are producing milk.

Secondly, factory machinery can be instantly replaced as needed, with no prior investment in the new machine, but each cow has an associated heifer replacement that has nutrient requirements for maintenance and growth. The nutrients required to maintain the population (cow, dry cow and heifer) can therefore be considered as the fixed costs of milk production.

If milk yield per cow drops and more cows are added to the herd to maintain the same milk supply to the processor, approximately 41 pounds of extra feed dry matter per day is required to maintain each cow plus equivalent dry cow and heifer, thus reducing efficiency.

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If milk yield increases, the opposite is true: two cows managed under the same system and each weighing 1,500 pounds will both have the same maintenance energy requirement, but their total energy requirement will increase according to milk yield.

A cow producing 33 pounds per day will require a total of 21.4 Mcal per day whereas a cow producing 65 pounds per day will require 31.6 Mcal per day. This equates to an energy cost of 0.65 Mcal per pound milk for the 33-pound cow compared to 0.48 Mcal per pound milk for the 65-pound cow, i.e., reduced feed cost per unit of milk.

Regardless of the production system, in these difficult financial times, producing more milk per unit of feed through improved efficiency is crucial to ensure economic sustainability.

It seems obvious that modern dairying is not only economically sustainable, but also more environmentally sustainable than historical systems. As we make gains in efficiency, we produce more milk, using fewer resources (feed, land, water, energy and fertilizer).

Yet we often hear that the carbon footprint per cow has doubled – modern cows are bigger, they eat more, drink more and produce more waste and methane. This is true, but it’s only part of the story.

To allow true comparisons between different dairy systems we need to look at the entire production process, which means accounting for the resource requirements to maintain all animals (milking cows, dry cows, heifers and bulls) in the population and to express the carbon footprint per gallon of milk produced, not per cow or per acre.

When we account for the improvements in efficiency over the past 60 years, we see that the carbon footprint per gallon of milk has been reduced by 67 percent between 1944 and 2007 – an amazing achievement and a strong advocacy message that we need to relay to the processor, retailer and consumer.

Back in 1800, each farm could only produce enough food to feed one other family; nowadays, with our highly efficient agriculture, each farmer produces, on average, enough food to feed 125 other people.

However, we remain in the midst of a global food crisis, with an ever-increasing national and global population and a need to increase food production by 60 percent in the next 50 years.

The challenge to the dairy industry is to continue to make efficiency gains that improve profitability, reduce resource use and cut the carbon footprint of dairy production while improving outreach and education to reassure the consumer that U.S. milk is safe, wholesome, healthy and nutritious.

True sustainability within the dairy industry can therefore only be achieved by a balance between economic viability, environmental impact and social responsibility. PD

Dr. Jude Capper is a post-doctoral research associate within Professor Dale Bauman’s group in the Animal Science Department at Cornell University.

Dr. Jude Capper

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