June 11, 2007	Monday	Jamadi-ul-Awwal 25, 1428

THE livestock sector contributes nearly 50 per cent to value addition in the agriculture sector, and almost 11 per cent to GDP, which is higher than the contribution of the crop sector (47.4 per cent in agriculture and 10.3 per cent in GDP).

The role of livestock sector in the rural economy is very critical as 30-35 million rural population is engaged in this sector for their livelihood. Within the livestock sector, milk is the largest and the single most important commodity. Despite decades of neglect, Pakistan is the fifth largest milk producer in the world.

Cotton plays an important role in the economy. It accounts for 8.6 per cent of the value- added in agriculture and about 1.9 per cent to GDP. During the year 2005, the crop was sown on an area of 3.096 million hectares with production of 12.42 million tons. In addition to providing raw material to the local textile industry, the surplus lint is exported. Cottonseed is an important source of oil used in cooking. Low grade oil is also utilised in soap and lubricant manufacturing. Residual seedcake is a valuable protein concentrate used for livestock feed.

Cottonseed meal is an excellent protein supplement for cattle. The limitations on effective utilisation of this product in rations for swine and poultry are of minor significance for ruminant animals. Both decorticated and un-decorticated cottonseed meal have a constipating effect on cattle, which is beneficial in feeds with high molasses content. Calves are susceptible to harmful effects of gossypol because of incomplete rumen development. Hence it is recommended that concentrates for calves under five months of age should contain no more than 10-15 per cent cottonseed meal.

Cottonseed meal has relatively low rumen degradability and is, therefore, a good source of by-pass protein and especially useful in rations for milking cows. Producers obtained over 9 litres of milk/day over 300 days with peak milk yield at 12 litres/day, by supplementing sugarcane tops and roadside grasses with 0.25 kg cottonseed cake/litre milk. The results were the same as those obtained with 0.5 kg/litre of commercial compound feed (17 per cent CP).

Cottonseed meal can also be used in rations for growing chickens if the free gossypol does not exceed 0.03 per cent. Below this level, iron (2:1 iron to free gossypol) will completely overcome the depressing effect. As cottonseed is low in lysine, it may be necessary to make up for this deficiency by adding lysine. Prepress solvent-extracted meal may be used in layer feed if the gossypol has been inactivated with iron (4:1 iron to free gossypol), if the free gossypol content is not above 0.4 per cent.

As determination of the amount of free gossypol in a meal requires laboratory facilities, ferrous sulphate may routinely be added to diets containing cottonseed meal. For instance, for layers 0.05 per cent iron (corresponding to 0.25 per cent ferrous sulphate septahydrate) can routinely be included in diets containing up to 10 per cent cottonseed meal and up to 0.16 per cent iron in rations containing greater amounts. Broilers cannot tolerate more than 0.07 per cent iron in diet.

Whole cottonseed may be used as a feed for mature cattle, as is often done where proper milling equipment is not available. It is usually soaked in water and fed in small quantities as a supplement to green feed. Compared to the extracted meal, it has lower protein content and much higher oil content. High levels may cause scouring. The degradability characteristics of the protein should be similar. Delinting of fuzzy whole cottonseed to delinted whole cottonseed results in a higher protein and fat content and lower fibre content.

Cottonseed hulls are the parts of the cottonseed head that is left after the cotton and meal have been extracted and are normally considered to be a very low quality feed for ruminants. The results of two recent trials have shown that they are capable of supporting moderate growth rates in sheep. When a small amount of by-pass protein was added to the diet of cottonseed hulls + urea + 50 g lucerne + vitamins/minerals, the growth rate of lambs exceeded 130 g/day and wool growth was increased from 6 to 9 g/day.

Investigation of the rumens of these animals showed that protozoa were either eliminated or in very low population densities. This could be the reason why cottonseed hulls support such reasonable growth rates, even without supplementation with by-pass protein. Intake of cottonseed hulls by sheep is higher (c. 1 kg DM/day) than would be expected of a 40 per cent digestible feed and this is possibly associated with a rapid breakdown of the indigestible material in the rumen. As cotton hulls are available at the mills where the meal is produced, mixtures of meal and hulls can be bought. An economical fattening ration for cattle is 20 per cent meal and 80 per cent hulls, together with 3-4 kg of grass daily and a mineral supplement.

Various experiments with dairy cows showed that the roughage value of cotton hull is better than grass hays and nearly equal to high quality Bermuda grass but inferior to mixed clover hay. There is no effect when a cottonseed hull is substituted for corn or barley. There is some evidence that cottonseed hulls fibre maintains milk and fat yield even when DM digestibility of the diet declines as a result of substitution of cottonseed hulls for lucerne hay. In some diets, cottonseed hulls may have a special value because of a stimulatory effect on feed intake, not through improvement in digestibility.

Cottonseed hulls have frequently been included in complete diets for young, growing and lactating cattle. Replacement of rice bran with up to 20 per cent cottonseed hulls did not affect milk yield or fat content of buffaloes. Cotton wood is also used in some countries as a cattle fodder. Stems, branches and leaves can be ground, ensiled or hydrolysed with sodium hydroxide for feeding to beef cattle.

So, it is concluded that cotton, in addition to supplying raw material for fibre and oil industry in Pakistan can contribute towards the development of livestock industry. Cotton crop can uplift the production of meat and milk in the country by providing feed to livestock in the form of cottonseed cake, whole cottonseed, cottonseed hulls and cotton wood.