Welcome to The Dairy Mail

by Liza Bohlmann

Milk farmers who aim to excel in a competitive market can do so by paying more attention to the details of their farming operation,especially when it comes to feed conversion efficiency.

The many facets of farming mean that precision farming can be implemented in almost every aspect of farming – whether crop production, feed rations or computerised herd monitoring.

Most farms, including many pasture-based dairy farms, have some form of additional feed and feed supplements available to the dairy herd. Taking care of the detail of the correct combination and amount of feed and supplements can improve the productivity of the herd while improving the bottom line.

In most totally mixed ration (TMR) feed­ing systems, maize silage is the bulk feed for dairy cows. However, not all silage is created equal. Without analysing feed and knowing the mycotoxin status of the particular silage bunker in use or the quality of roughage ­included in the ration, it becomes very difficult to prepare a balanced TMR for dairy cows. This in turn affects the productivity and feed-to-milk conversion rate.

At the recent Alltech Global Dairy 500 seminar hosted in Lexington, Kentucky, USA, Dr Mike Hutjens from the University of Illinois spoke to dairy farmers about feed efficiency, focusing on how to increase the net income without compromising quality.

South Africa was represented at the event by Nigel Lok, MPO director and Easter­n Cape dairy farmer, who was invited as one of the speakers.

Hutjens highlighted the benefits of the measurement and improvement in feed efficiency. This includes several measurable variables including the cost per cow per day, feed cost per cow and cost per pound of dry matter.

According to Hutjens the progressive farmer should aim to produce milk for less than US$6 per cow. This translates (at an R/$ exchange of R7,15) to R42,90.

He warns against reducing the feed programme by cutting back on concentrates, feed additives and quality silage and roughage.
“This can be detrimental to feed efficiency. If you move from 80 lb (36,29 kg) to 70 lb (31,75 kg) feeding will become less efficient. There’s a lot of money to be made by measuring and improving feed efficiency.”

In order to measure and track efficiency, Hutjens highlights three methods:
• Use a dairy software program
• On-farm measurements
• Adjusted feed efficiency (AFE)
“Nutrition does play a role in feed ­efficiency; therefore, producers should consult with their nutritionist or feed company to see how rations and supplements can ­improve.”

Precision pays
Kenneth Botha, technical director: Ruminants at Afgri Animal Feeds, says the focus for ­productivity on a dairy farm must be efficiency.

Improved efficiency means the farmer needs to produce the same amount of milk with less feed or more milk with fewer cows or both on a dairy farm.

“To accomplish this, the dairy farmer must aim to produce the highest quality of self-grown roughages and use the correct concentrate and supplements to complement these roughages,” says Botha.

“It is always difficult for a nutritionist to formulate a diet if there are only low-quality roughages available. Many dairy farmers do not measure efficiencies; therefore, they cannot measure the efficiency of individual dairy cows or growing heifers. If one does not measure, one cannot improve,” says Botha.

Individual cow management
One of South Africa’s most knowledgeable farmers on the subject of individual feedin­g specific to each cow’s needs is Nigel Lok who farms with Jerseys, Holsteins and crossbred Jersey-Holsteins.

Taking individual control of each cow in his herd is how Lok manages his pasture­-based herd on his farm, Robhoek, in the Tsitsikamma. Cows have pedometers to monitor activity (this makes heat spotting easier) and electronic ID tags that register each cow’s weight, milk production and also keeps record of treatments, vaccinations and artificial insemination, among others.

The individual computerised control over every cow at every milking is incorporated into an automatic supplement and concentrate feed system. In this way, Lok can ­manage each cow as an individual to her own genetic ability.

At Robhoek, the automated AfiMilk ­monitoring system and incorporated individual in-parlour feed system helped to improve milk production by 30% with the same cost structure.

AfiMilk is a world leader in dairy technology innovation by Afikim, an Israeli-based company. Globally, AfiMilk systems and products have been installed in more than 50 countries with more than 1 600 computer­ised management systems, 110 000 milk ­meters and over a million ID tags, monitoring dairy herds day and night.

The individual and herd data collected electronically enables the farmer and personnel to monitor the early onset of mastitis effectively, analyse individual milk yield and components, monitor each cow’s production throughout the lactation period, ­metabolic problems, body weight and oestrus ­(indicated by increased activity).

Each cow is fitted with a pedometer, which combines two functions: by acting as an electronic ID for every single cow in the herd and a steps counter, which indicates the activity level of the cow.

According to Lok’s testimony on the effectiveness of the system, he has concluded that feeding is the basis of everything.

“If we can feed cows properly and keep them on the correct weight curve, we’ll get the maximum benefit. Afikim enables us to calculate and determine the cow’s ideal body weight, check her body weight through her lactation and make adjustments automatically to her feeding to keep her on the correct weight curve, at the same time feeding her for production.

“The carry-over benefit of this has been an increase in fertility. We brought our intercalving down – from 410 days, we are down to 379 days, after implementing the system. Initially, we spent a lot of time on it. However, it has come to a point where it is pretty much automated.

“The cows that go off their weight or go off their food or where production drops, will be sorted and separated automatically as the system will identify those cows, herd them automatically and print the automated report so that the stockmen can do what is needed,” Lok states in his testimony on Afimilk.

Looking after rumen health
Beyond the feeding trough lies the rumen and here too the farmer must manage and monitor more precisely for better results. Managing this power plant of the cow is as important as any other management tools used towards more precise farming.

Rumen health is critical for efficient conversion of dairy cow feed into nutrients. Rumen disorders such as acidosis (suurpens) is a major cause of economic losses and herd health issues in the dairy industry and important in maintaining the rumen health and overall welfare of the animal.

Rumen health of dairy cows includes taking care of and gaining more knowledge on specific focus areas. These include the impact of rumen pH on ruminal digestion, the occurrence and prevention of sub-acute rumen acidosis, maintenance of an optimum rumen function and ruminal adaptations during the transition period.

One of the concepts to understand is that rumen health has much to do with the way beneficial microbes operate in the rumen. These microorganisms help the cow digest her food.

Speaking to Richardt Venter, Vitam International’s product manager: Ruminants, South Africa, he makes it clear that feeding the rumen correctly is of utmost importance.

“The feeding concept for the modern day dairy cow with its improved genetics means that feeding should evolve alongside improved animals,” says Venter.

Feeding the beneficial microbes in the rumen and creating a suitable environment for these little digestion helpers should be part of any feed regimen.

“The cow’s rumen is a fermentation ­organ and fermentation occurs with the help of ­microorganisms. This is what distinguishes the ruminant from other animals and enables the cow to use roughage (grass, silage and others) as food,” he continues. Keeping this in mind, the occurrence of acidosis should be considered when compiling a ration in conjunction with an accredited animal feed consultant.

“Cows are designed to eat roughages but we also feed them concentrate feeds consisting of grains such as maize, wheat, sorghum, oilcake (from high-protein sources such as soya, sunflower and cotton oilcake) and other products such as hominy chop and wheat bran that can cause acidosis.

“The fermentation tempo of these grains is so fast that acid such as lactic acid increase too much too fast. This results in the rumen pH decreasing to an unnaturally low level. A too-low rumen pH adversely affects the microbe population in the rumen. This means that these microbes die off, leaving the rumen with an incomplete microbe population and a decreased ability to ferment the feed inside the rumen.

“When all the microbes are destroyed a situation known as rumen stasis occurs and the rumen will be rock hard and packed with undigested feed, making it impossible for feed to move from the rumen to the rest of the digestive system.”

There are two acidosis types, Venter explains. Sub-acute rumen acidosis (SARA) occurs when the animal’s rumen pH is consistently low and verging on overly acidic levels. A pH below 6,0 for longer than four hours per day is considered as SARA.

Cows presenting a pH below 4,0 for short periods per day is relatively normal for cows on concentrate rations. However, if this low pH is maintained for more than four hours per day, the rumen can be damaged. A pH that is constantly below 5,5 amounts to acute acidosis.

To help prevent acidosis – and if it is known that low rumen pH is a problem – the farmer can use ‘buffers’ such as bicarbonate of soda and magnesium oxide, or any commercial buffer, Venter advises.

Prevention
“There are also specific products available that act on lactic acid in the rumen. This includes the commercial form of live Megasphera elsdenii, which acts on lactic acid in the rumen.

“However, prevention is better than cure and the prevention of a low rumen pH should be the feed consultant’s aim. This starts with the correct feed formulation and maintaining the correct concentrate and roughage ratio. Unfortunately, it is not as simple as employing a 60:40 or 50:50 ratio, as factors such as effective energy levels and the tempo of starch fermentation must be taken into account for each ration,” Venter says.

“Products such as Levucell SC are live yeasts that can act preventatively against acidosis, since it reduces the production of lactic acid indirectly and improves the usage of lactic acid indirectly. This helps to reduce feeding intervals, increase the frequency of feeding and thus the production of saliva which is the most important buffer against a too low pH.”