23.0 MANUFACTURE AND UTILISATION OF MULTINUTRITIONAL FEED BLOCKS (MB).

23.1 What are feed blocks and their main effects on animals ?

Feed blocks are a feed supplement which can enhance efficient utilisation of native and improved pastures. Their main effect on animals is to increase appetite and intake of poor-quality forages and pastures which boosts animal performance and consequently improves productivity. The solid mixture contains urea (10%), salt (10%) and local by-products incorporated into a block structure that is licked by animals.

23.2 What are the ingredients in the formula of blocks?

whatever the applied formula, the common ingredients in feed block are:

Table 16. Two satisfactory formulas which can be successfully applied in PlC's:

Ingredient

Formula 1 (kg per 100)

Formula 2 (kg per 100)

Copra meal

45

60

Molasses

20

0

Cement

15

20

Urea

10

10

Salt

10

10

TOTAL

100

100

Water

25

40

 

23.3 How to make feed blocks?

The manufacture technique is simple, and easily accessible to small farmers. The equipment required is very simple and relatively cheap. Mixing may be done by hand, in a concrete mixer or in a horizontal barrel mixer. Whatever the applied formula, the steps for making the blocks remain the same. These steps consist of: weighing, mixing, moulding and drying. Small (10 to 20 kg ) or large (50 to 100 kg) quantities can be prepared in each batch

 

The procedure presented hereafter is concerning uses Formula I [see above]. Steps for making up the mixture (100 kg) are:

23.3.1 Mixing

(i) Urea (10 kg) is mixed with salt (10 kg) in a large container. A solution is made up

using 25 litres of water. Avoid urea lumps as this could lead to animals being poisoned due to an overdose. Then add molasses (20 kg) and stir the mixture well with a wooden stick for five to ten minutes (see Photo 31.)

(ii) The specified amount of copra meal (45 kg) is placed on the ground in a round heap on a hard and even concrete drying floor. Then add to it the amount of cement ( 15 kg). The mix of copra meal-cement is thoroughly mixed using shovels and/or forks (see Photos 32 and 33). For preparation of small amounts ( 10 kg ) the mixture can be prepared by hand in a large plastic bowl (see photo 34.)

(iii) when the mix of copra meal-cement is carefully mixed, form a hole in the middle of the heap and gradually sprinkle by hand or using water sprinkler the mixed solution of "molasses-salt-urea" and carefully knead until a uniform paste of good consistency has been prepared (balls should not disintegrate when moulded in the hands). If these balls tend to crumble, then one should add a little more water (3 or 5 litres) and continue mixing (see Photo 35.).

23.3.2 Moulding

Once the mixture has been properly kneaded, small amounts are progressively stacked into separate moulds. The cubic mould type (20 x 20 x 20 cm) consists of four flat pieces of wood in which slots have been made so that they can be easily assembled to form the mould and then later dismantled when the brick is removed (see Photo 36.)

The mixture is then strongly compacted in the mould using a heavy wooden or metal pounding rod (see Photo 37.). Simpler motilds can also be used, such as half buckets, cans cut to size or any other receptacle which is locally available. Taking the bricks out the motilds may be eased if they are lined to start with, using plastic sheet

23.3.3 Drying

(i) Once the mixture has been well compacted, the blocks are carefully taken out of the moulds and arranged on a drying floor (see Photo 38.), preferably in the shade as the strong sun can cause cracking in the blocks. The blocks will dry and be ready for use after about 10 days. Blocks weighing 8.5 to 10 kg when dried can be made with this type of mould.

The blocks should be sufficiently resistant for transport and hard enough to withstand licking without crumbling (if too friable large chunks could be munched by animals thus increasing the risk of urea toxicity).

If blocks are not hard enough or are friable, this could be due to:

-errors in the quantities of the ingredients (probably insufficient water)

insufficient uniformity in preparing the mix, mainly pellet forming from wet copra meal

insufficient packing down of the mix into the mould, poor quality bonding material: cement which is too old, poor solutions with only part of certain ingredients being dissolved (urea, salt,...)

If friability persists despite all these precautions, increase the amount of the bonding agent. On the contrary, if blocks are too hard the amount of cement can be reduced to I 0% instead I 5%. when the quantity of the cement is increased or decreased, incorporation rate of copra meal must also be modified.

Once dried the blocks can be stored in a dry place for several months up to year. Their quality varies very little.

23.4 How to use feed blocks?

Blocks constitute a feed supplement that improves utilisation of poor quality-forage and unbalanced grasses. How to use these blocks depends upon the feeding system. If the animals graze pasture, the farmer can leave the blocks available to them in a sheltered trough (see Photo 39). when animals remain in confinement (animals being milked or fattened ) and are fed with silage and cut grasses, the farmer can leave the blocks available at all times in feed box.

Finally one should always recall that blocks contain urea which can be toxic if consumed in excess of the normal dose; it is therefore recommended to respect the following precautions:

a. Only give the blocks to ruminants because only ruminants are able to take advantage of the urea in the blocks. The blocks should be not given to pigs, equines, chicken. Calves can have access to blocks after the age of 2-3 months. Wet blocks (due to rainfall ) become very soft and can easily cause intoxication due to urea high intake. Consequently blocks should be always kept under shelter and far from water trough

b. Blocks should be used as a supplement and not as the basic ration. Feedblocks are catalytic" supplements which allow ruminants to take better advantage of native and improved grasses or protein-poor by-products (from bananas, crop roots....). But they should not be used to replace them.

A minimum of coarse forage in the rumen is essential. Therefore, the farmer should not give the blocks to an animal with an empty belly as one risks causing feed poisoning due to an excessive consumption of urea.

c. when first introducing blocks it is advisable to respect a transition period. Offer blocks progressively over a period of two weeks so that the animal becomes adapted to this new supplement which contains urea. when animals are reluctant, the farmer can put some copra meal or other appetising product, such as molasses, salt or chopped grassed on top of the block to help the animal become accustomed to it. Once the animals are adapted to the supplement, they will regulate their intake on their own and the blocks can be left available all the time.

d. The feed block intake per head varies between 250 to 400 g I day for adult cattle when intake is lower or higher, the farmer may check the hardness of blocks. This can be corrected

by modifying the proportion of bonding agent in the formula: add more to increase hardness or

reduce it to make the block softer.

e. Finally availability of the blocks should be regular and continuous so as to avoid having to undergo another adaptation period for the animal, which in fact will take another two weeks each time distribution of these blocks has been discontinued.