1. INTRODUCTION TO MANAGEMENT

This is a term which is very loosely used and, in fact, is one of the most complicated aspects of farming today. In certain circumstances it can be regarded as the most important factor of all. Management in Dairying is beset with problems as it entails a tremendous amount of attention to detail. The purpose of this section is to draw your attention to these details and to list the factors which should be considered top priority.

When considering management in relation to the Dairy enterprise, one should look at the different sections within the unit before deciding what is required in terms of management. The different sections that can be identified are:

  • The Calf Unit;
    • The Heifer Unit;
    • The Cow Unit and;
    • The Dairy.

These represent only a few of the units within the dairy but they are probably the most important. Within each unit, there can be a further breakdown to detail requiring basic management skills.

It will be assumed that the calf unit is specialised unit and while there are not many details to be considered in this unit, the farmer still has to provide suitable housing and routine

feeding of milk with the gradual introduction of roughages. Calf identification and inoculation also require specific attention.

The calf has first to pass through the danger period. That is from the time of birth, for the first 4 days, when the calf is feeding colostrum from the cow which is essential for the first days of its life, until it is weaned and sent to join the replacement stock. Good management is vital to this unit,  from every perspective for the serious farmer. ( See Module 5 on Calf Rearing)

Management of the heifer and a thorough understanding of its growth and development is important, as we are producing what we hope is going to become a productive replacement for an unproductive animal in the herd. What follows then is a summary of the more important points to remember when rearing heifers for replacement. This, of course, is apart from routine dipping and dosing programmes which have to be carried out.

2.   MANAGEMENT OF THE DAIRY HEIFERS

It has already been emphasised that the most important single factor in determining the financial outcome from a dairy herd is the productive capacity of the individual cows. The most positive method of producing or developing a high yielding herd is by replacing the poor producers with “well bred” home-raised heifers of greater productive capacity. Such heifers should be from the best cows in the herd; and they should be served by a pure-bred bull which has been selected for ability to transmit high production with a considerable capacity for converting feed into milk.

The farmer who follows the opposite plan of purchasing his replacements will often be badly disappointed, even if he is careful to buy only heifers or cows whose appearance is promising. The farmer from whom he buys will naturally desire to retain for his own herd the heifers out of his  very

best cows. In addition to the difficulty of buying animals which will prove profitable, there is also much more danger of introducing disease when the replacements to the milking herd are continually purchased.

This illustrates the necessity of knowing exactly what one has in terms of genetic potential, and the best source of information in this regard is the farmers own personal records.

GROWTH

Growth is one of the oldest of phenomena, yet we have hardly begun to understand the principles underlying it. Growth has been defined as: the increase in volume in living material.

It is the result of three processes:

  • Multiplication of cells
    • Enlargement of cells
    • Deposition of intercellular substances

The first two are more important than the third. It has been established that the impulse to grow is implanted at the time of fertilisation of the ovum, and that the growth of the germ cell of the animal, from the time of fertilisation to that of birth, represents an initial gain of 1000% per day. It has been established that 98% of the growth impulse is used up at the time of birth.

Just as there are two factors related to milk production, so there are two factors related to growth:

  • Internal factors
    • External factors

The external factors are greater in importance to the farmer because they can be influenced by him to a greater or lesser extent.

Growth is characterised by two main functions, i.e. that of Early Maturity, and that of Late Maturity. The variation of growth in different animals is largely inherited. In other words, an animal inherits the capacity to grow. It will reach a certain size if given favourable conditions, and it will not exceed the genetic ceiling even under ideal conditions. Under adverse conditions there may be retardation in growth and the animal may never reach its full potential.

3.   MEASURING GROWTH

Since the fleshy part of the animal does not gain at the same rate as the skeleton, growth cannot be measured from live-mass alone. It has been established from certain observations that the best way to measure growth would be to measure the height of the withers. Thus, two methods can now be employed to measure growth:

  • Live-mass gain
    • Wither height

Table 1: Live-mass gain of dairy heifers

Age in months BirthHolstein Friesland Kg 44Jersey Kg 25
15433
6180126
12324236
18414300
24500372
36594431

Why Stress Growth?

The most important reason for stressing this phenomenon is that it can be controlled to a certain degree through management.

4.   FEEDING THE DAIRY HEIFER

Opinion as to the best manner in which to feed dairy heifers is divided. After the heifer is past the danger stage which is always present with young calves, and before she has reached the productive stage, the tendency has been to leave her to nature with as little care as possible. But this is incorrect and the heifer should be treated in exactly the same manner as a fully producing cow. That is, all the requirements for maintenance and production must be fully satisfied. But in these lectures we do not have space to deal with this in any detail. You must remember, however, that this aspect of management is very important.

The following tables give the Nutrient Requirements for heifers of different sizes and for large and small breeds.

Table 2: Daily nutrient requirements for growing heifers

Daily nutrient requirements for
growing heifers (Small Breeds)
Live-mass (kg)CP DCP
1000.3700.262
1500.4350.2952.7
2000.50.333.4
2500.570.3654
3000.640.3954.5
3500.7150.4304.9
4000.80.4655.2
4500.8850.4955.3
Daily nutrient requirements for
growing heifers (Large Breeds)
Live-mass (kg)CP DCP
1000.3200.211.6
1500.3900.2452.3
2000.4650.2802.9
2500.5500.3203.5
3000.5900.3303.8
3500.5850.3153.7
4000.5550.2903.6
4500.5800.3103.4

5.   FACTORS AFFECTING GROWTH

The most important factor to look at here is the live-mass of the animal in relation to her milk production. Observations carried out have revealed the following facts:

  • With an increase in live-mass there is a corresponding increase in milk yield and butter fat.
    • This is true of all breeds and illustrates quite clearly the necessity of having a good animal in terms of live-mass at the start of her productive life.
    • But there must be a distinct difference between fit animals and over-fat animals. Heavily fed animals become late breeders and as a result of this, become inferior milk producers. The over-fat heifers develop low-quality fatty udders with limited milk-secreting tissue result in poor production.

At this stage, it is quite clear that emphasis has been placed on feeding, and the results of such feeding. It is possible at this stage to discuss at length what to feed the animals and what would be the ideal live-mass of the animal when put to the bull for the first time. However, this is not necessary. The next most important aspect to look at is, in fact, the Age of Breeding.

AGE OF BREEDING

Effect of Early Breeding on Size of Animals

The age at which heifers should be bred depends upon several factors of which farm experiments carried out in the United States of America have shown these as follows:

  • Gestation had little effect on the rate of growth.
    • Lactation, on the other hand, did have a decided effect on growth when compared with heifers of the same age, un-bred or pregnant.

The most decided effect on the size of the heifer is when she is fed a light ration during the growing phase and is also bred to calve early.

This is probably the main reason why there are so many undersized cows found in many herds. This  is also true for the beef herds, where the same principles are involved. This indicates a lack of understanding of the principles of growth and is indicative of mismanagement.

EFFECT OF EARLY CALVING ON MILK PRODUCTION

Heifers that are well grown and somewhat mature will produce more milk during the first lactation than heifers calving at a younger age. But if we are to look at this a little more closely, we want to

observe the effect of early or late calving on the life-time production of the cow.

Again from observations carried out in the United States, the following facts were revealed:

The greatest difference in production with early breeding was in the first lactation. The observations made was clear, that it was important to have relatively mature heifers at the time of the first  calving to ensure a substantial and economic life-time production.