Understanding fodder flow

It’s crucial for livestock health and economic efficiency to bring herd size in line with the fodder production of the farm, so that sufficient quality dry matter is provided on an uninterrupted basis.

Understanding fodder flow

Supply of feed is a key factor on any livestock farm, yet this aspect of management is often neglected.

“Basic feed supplies are frequently erratic and inadequate because of poor planning aggravated by inefficient production practices and adverse weather conditions. It’s not economic to plug these gaps with concentrates,” says RI Jones of the Cedara Agricultural Development Institute.

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Concentrates are supplementary feeds and not staples, stresses Jones. “A constant supply of good quality roughage is the solid foundation of profitable dairy farming,” he says.

Fodder includes grazing, hay, silage, and roots.

“The objective of fodder production planning is to match the production capabilities of the farm to the animals’ requirements to obtain the greatest margin on feed costs, within safe limits of natural resource utilisation.”

Method
The first step is to draw up a stock flow programme to plan your fodder flow. Assess the grazing impact on pasture condition and biomass by using a disc pasture meter that measures plant height, or a similar method.

Then use the results of this to determine the correct stocking rate or grazing duration for a particular pasture. As a general guide, stocking densities of pens should not be less than 10m² per adult. Densities on pastures should not exceed 49 mature animals per hectare, with 24 to 26 preferable.

“The carrying capacity of the property, not the owner’s target income, should determine the size of the herd,” says Jones.

Dry matter
Draw up a table of all the animals in each productive and reproductive category for every month of the year. This will give you the total number of animals on the farm.

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Next, weigh or estimate their total weight and total dry material (fodder) needed. From this, calculate the total dry matter requirement per month in the year, using Table 1. These figures are derived from the US National Research Council standards for nutritional needs of ruminants.

Table 1. Nutritional needs of dairy cattle

These simple, well-known standards are generally applicable but can be adapted to specific conditions. See Table 2 for an example of the stock and fodder flow needed for January on a hypothetical farm.

Table 2. Stock and fodder flow required for January on a hypothetical dairy farm

Fodder flow is the total fodder available from each source (veld, pasture, stover) month by month. Ideally, this figure will exactly match the required feed flow, but as this rarely happens naturally, the match should be ‘forced’ by:

Deliberately altering the stock flow by strategic culling and calving; and/or producing more food at particular times; and/or Transferring excess fodder from one time of the year to another as hay, silage, or forage.

If you do not achieve the match, nature will force it on you anyway – firstly as a loss in production and reproduction (low fertility), then as a loss in live weight (thin animals), and ultimately as a loss of animals through forced selling or, in extreme cases, death from starvation. Fortunately, South African dairy farms rarely reach that state, says Jones.

“Nevertheless, the fodder flow often leaves much to be desired. In fact, it’s probably one of the major limiting factors to dairy production in South Africa.”

Symptoms

The problem usually manifests itself in the following ways:

  • An average milk yield below 5 000ℓ/Holstein-Friesland cows’ lactation (herd average of 17ℓ/lactating cow/day), even with generous concentrate level.
  • Concentrate usage exceeding 400g/ℓ of milk, averaged over all cows over the year, often associated with low butterfat level.
  • Large seasonal fluctuations in milk yield, if these are not caused by the calving pattern.
  • Thin heifers, underweight first-calvers (below 90% of mature weight) and poor first lactation results (under 4 000ℓ).
  • A disproportionate number of thin cows in the herd.
  • Low fertility, even among young animals.

“Individually, these problems often arise from causes other than feeding, but if three or more of them occur together, the first place to look for [origin of] the trouble is in the fodder flow,” says Jones.

Source: Hawkins H-J, Stanway R: The Sustainable Dairy Handbook, Nestlé Printers, Bryanston, SA; Jones, RI: ‘Fodder Production Planning for the Dairy Herd’, KZN department of agriculture.