Meeting the demands of goats with forage

Maize silage forms an integral part of the ration for Will Frost’s award-winning herd of goats on Forde Abbey Estate in Somerset. Maintaining its quality is essential to their performance and wellbeing.

To all intents and purposes, a milking goat is much like a dairy cow in miniature – at 65kg it’s around one tenth the weight, and production is 10% that of a high yielding Holstein. 

So, when dairy farmer, Will Frost, switched to goats from black-and-whites over 20 years ago, he had exactly the right background to deal with their management at Forde Grange Farm, rented from Forde Abbey Estate near Chard in Somerset.

He obviously adapted well, as by 2019 he had been awarded Dairy Farmer of the Year in the prestigious Farmers Weekly Awards – an accolade which had never before been won by anyone other than a farmer milking cows. 

However, it was long before this that he recognised the peculiarities of the species he had taken on, and clearly understood that its management had to be fine-tuned to reflect its quirks.

Now milking around 2,500 Saanens as part of a 650-acre (263-ha) contract-farming operation with Forde Abbey, he says both nutrition and environment have to be carefully balanced.

“If you get her nutrition and environment right, the goat has the ability to reach her peak production at 100 days and maintain a fairly flat lactation for several years,” he says. “Apart from those females which are selected to breed replacements, our goats normally only kid once – we have some which are 1,000 days in milk.”

The herd’s resulting average annual production weighs in at around 1,200 litres at 3.71% fat and 2.71% protein on twice-a-day milking, all supplying a liquid contract for Delamere’s Shepton Mallet dairy.

High D-value forage

Maintaining the goats’ production, health and optimum body condition throughout their extended lactation is a balancing act, in which nutritionist, Sam Cottam, from Advanced Ruminant Nutrition, plays an important part.

“On Will’s farm, we are maximising the use of forage to optimise both cost-effectiveness and animal health, and with goats, it is even more important than with dairy cows that the forage has a high digestibility.

“Goats will eat even more than cows as a percentage of their bodyweight, generally consuming dry matter about 5-6% percent of their weight, compared with dairy cows at 3-4%,” he says.

“Their gut retention time is therefore lower, which means the rumen has less time to use the forage, so to get more out of it, the forage needs to be more digestible.”

Achieving a high digestibility (D-value) in the maize silage is addressed from the very start, beginning with the choice of varieties.

“We grow around 300 acres [121ha] of maize of which 200 acres [81ha] are for the goats,” says Will. “We start by selecting early varieties – normally maturity class eight or nine – which will typically be harvested in mid- to late-September, at a dry matter between 30% and 35%.”

These actions – plus the choice of low lignin, high digestibility maize varieties – help in achieving the highest possible D-value, which in Will’s silage is typically around 72 to 73.

“Then it’s down to reducing clamp losses, by eliminating oxygen as fast as possible by speedy filling and effective packing and sheeting,” adds Sam.

For this, Will chops the crop to 10-12mm and usually uses a SilaPactor for added compaction. This has the scope to increase the density of the forage in the clamp by up to 40%.

In addition to 150-micron side-sheets, Farmguard is used on the top of the clamp. This is an innovative, seven-layer single sheet with up to 100 times the oxygen impermeability of standard silage sheeting. 

Also fully recyclable, Will says he will repurpose the Farmguard sheeting for a second year, using it for a composting trial he is undertaking as part of the Triple Axe River Catchment Project.

Fast lactic fermentation

“The goal with the maize silage is to convert carbohydrates to lactic acid as this is the most efficient fermentation and involves no loss of carbon dioxide [CO2],” continues Sam. “Alternative fermentation pathways produce CO2 which you don’t see and which represents a loss of energy.

“Lactic acid is a strong acid and the faster you create it, the quicker you achieve a drop in pH, which in itself inhibits microbial growth,” he says.

For this reason, Will has stuck with Safesil Pro as his maize silage preservative over the decades, which has been independently proven to achieve long-term storage stability through the type of fermentation Sam describes.

Body condition in late lactation

Another consideration with the late lactation goats is the avoidance of too much body condition, particularly when it’s considered that some groups average 600 days in milk.

“The goats are in groups of 200 to 250 and we closely monitor their intakes,” says Sam. “If, for example, the late lactation groups were eating 20% more than 

they’d been rationed for, we would reduce the energy density of their ration by cutting concentrates and increasing forage, which would take out cost and improve animal health.”

Negative energy balance

In early lactation, the opposite issue has to be addressed as Sam says goats are more prone than cows to falling into negative energy balance.

“They will readily lose 10% of their bodyweight and seemingly have no metabolic issues,” he says. 

However, unlike a cow which may become ketotic in early lactation, the goat’s problem time is more likely to be late in her pregnancy.

“The big drain in the goat comes from the foetus, especially if she’s carrying multiple kids,” he says. “Historically, we have therefore given these pre-kidders the same ration as the high yielding group, including protected fat, to maintain energy intakes.”

However, the team has recently devised a pre-kidders’ ration with higher protein and a custom mineral pack. This has improved the quality of colostrum and early lactation milk, reduced udder oedema and helped maintain body condition and intakes in early lactation. 

Most critically, the quality of home-grown feeds remains high in all rations whether that’s grass silage, preserved with Safesil Challenge or crimped wheat, preserved with CrimpSafe 300.

With goats generally able to manage a high starch diet, its high levels in crimp come in particularly useful.  

“Two years ago, we all had to deal with very high feed prices, especially for soya. Cows’ milk price went up at the same time, whereas goat milk did not,” says Will. “Having a high proportion of home-grown feed in the ration was a great help to our bottom line at the time. It’s also useful for marketing and is generally a good principle.”