Multinutrient lick blocks for dairy cattle in Gansu province, China

Multinutrient lick blocks were manufactured for Holstein-Friesian cattle in Gansu province to improve the low milk yield caused by unbalanced feed and nutrient deficiencies. Three formulae (for cows, heifers and calves) have been formulated. The manufacturing process of the blocks has been tested using two types of presses. Supplementation with blocks increased milk yield by 6.7% and daily gains of growing heifers by 15.5%. Body condition was also improved.

In China, Holstein-Friesian cattle are mostly kept in sheds. The average milk yield per cow in Gansu is 20% lower than the national average due probably to imbalaned feeding systems. The forage consists mainly of wheat straw since green fodder is only available for four or five months of the year.

The use of licking blocks is not a new practice for the Chinese farmers. Multinutrient blocks (Sansoucy et al 1987) provide non- protein nitrogen (NPN) in the form of urea also minerals and vitamins. This helps create an optimal ruminal environment which stimulates the digestion of the basal diet increasing not only digestibility but also the roughage intake.

Blocks are highly palatable when they contain molasses; they are consumed in small amounts throughout the day due to their hardness -- a feature that increases the efficiency of urea use. They are easily transported and offered to the animals.

Three formulae were chosen to satisfy the needs of: cows, heifers and calves). The price and the processing characteristics of the ingredients are given in Table 1).

The blocks were made by mixing the molasses and urea first. This mixture was heated and the salt added, followed by the addition of the rest of the ingredients previously mixed together. The complete mixture was than pressed and the resulting blocks were wrapped immediately.

Table 1. Formulae of the multinutrient lick blocks for dairy animals

Ingredients	Cow	Heifer	Calf

Molasses	8	10	15
Urea	16	12
Salt	26	26	22
Ground corn	5	5	10
Lime	10	10	10
Clay	11.2	15	15
Bone meal	-	-	5
Mineral mixture	23.8	22	22.2
Total	100	100	100

This work also included the design and building of press machines for the formation of blocks. The characteristics of two presses are shown in Table 2.

Table 2. Characteristics of presses used for making the blocks

Press type	Power source	Dimensions (m)	Weight (kg)	Work pressure (kg/cm2)	Production capacity (kg/h)

9YK-50	Hydraulic	0.6x0.7x1.0	240	52	50
Manual	jack (50
	tonnes)

9YK-150	Hydraulic	0.75x0.4x2.0	640	176	150
electrical	pump
(0.75Kw)

To determine the effects of block on animal performance, extended feeding trials have taken place in five dairy farms (State, Collective and Private) with a total of 344 Holstein-Friesian animals. One trial was carried out to determine the effect on milk production of 30 cows during a period of 121 days, another to evaluate the growth of 42 heifers.

Blocks made using both press machines were of a good hardness; the breaking strength was 44 kg/cm2. The nutritional values and composition of the three block formulae are given in Table 3. The blocks were of good quality, did not absorb moisture, did not become mouldy or nor did they lose shape when exposed to rain or sunshine.

Daily consumption (g/d) was on average 150, 100 and 50 for cows, heifers and calves, respectively.

Table 3. Nutritional characteristics of the multinutritional lick block.

	Cow	Heifer	Calf

Dry matter (%)	95.8	95.1	96.1
% in dry matter
N x 6.25	40.0	31.1	20.0
Ca	2.3	1.1	4.3
P	5.0	3.3	0.4
In mg/kg DM
Cu	933	651	140
Zn	5412	1814	1002
Mn (mg/kg)	3140	2825	804
Fe	1193	1198	1124
I	113	-	-
Co	17	5	5
Se	57	26	42
Vit D3	0.03	0.04	0.02
Vit E	-	-	0.20

Results from the test with dairy cows are given in Table 4. Cows supplemented with the block had an average milk yield of 20.7 kg/day which is 1.3 kg or 6.7% higher (P<0.01) than the average of the control group.

Table 4: Effect of the multinutrient block on the daily milk yield.

	Number	Milk yield
		(kg/day)

Control	15	19.4
Block	15	20.7
Probability		<0.01

In the growth trial, animals having access to the licking blocks had a daily gain of 0.835 kg/day which is 0.112 kg/day (P<0.05) higher than the control group (Table 5). Animals supplemented with the licking blocks would reach 380 kg body weight (weight at the first service) 65 days earlier, giving an earlier first calving.

Table 5. Effect of blocks on the average daily gain of heifers.

	Number of animals	Daily gain (kg)

Control	21	0.723
Block	21	0.835
Prob		P<0.05

Other advantages observed during the animal feeding trials on the farms were better skin coat and better body condition. The Lin Ze dairy farm in Gansu reported savings on the animal health budget during the year of block supplementation and that the annual death rate had dropped from 6 to 1% during the three years of block feeding.

The results in this study show that multinutrient molasses-based blocks improve the productivity of dairy animals. Blocks are easily produced and transported. In addition, they can be incorporated in daily feeding regimes with very few difficulties. The formulae can be adapted according to the feeding regime and to the kind of animal. It may be concluded that there is a good future for licking blocks in China.

Sansoucy R, Aarts G, and Leng R 1987 Molasses-urea blocks as a multinutrient supplement for ruminants. In "Sugar cane as feed", Animal Production and Health paper No. 72. FAO: Rome