6 A goat farmer in a semi-arid region relies on natural browse and crop residues to feed a herd of 50 dairy goats. During the dry season, forage quality dec...

(a) Two nutrients likely to become deficient in the dry season [2]

When forage quality declines during the dry season, browse and crop residues become lignified and less nutritious. Any two of:

1. Protein - dry, mature forage has much lower crude protein than young green growth, often falling below the minimum needed for milk production. [1]
2. Energy / carbohydrates - dry forage has lower digestibility, so the goats extract less metabolisable energy per kilogram eaten. [1]
3. Vitamins (especially vitamin A) - green forage is the main source of carotene (pro-vitamin A), and dried forage loses much of this.
4. Minerals - trace element supply may fall if the forage species change or dry out.

(b) One locally available protein supplement [1]

Any one of: cottonseed cake, groundnut cake, sunflower cake, leucaena or calliandra leaves (tree legume foliage), or soybean meal. [1] These are high-protein feedstuffs available in many tropical and semi-arid regions.

(c) Explanation of feed conversion ratio [2]

1. Feed conversion ratio (FCR) is the amount (mass) of feed consumed by an animal. [1]
2. Divided by the amount of product gained or produced - for example, kilograms of body weight gained or litres of milk produced. [1]

A lower FCR means the animal is more efficient at converting feed into product. For example, if a goat eats 4 kg of feed to produce 1 litre of milk, the FCR is 4:1.

(d) Two practical steps to maintain milk production in the dry season [2]

Any two of:

1. Conserve forage as hay or silage during the wet season for feeding in the dry season, ensuring a continuous supply of reasonable-quality roughage. [1]
2. Supplement the diet with concentrate or protein-rich feeds (oilseed cakes, cereal bran) to compensate for the decline in forage quality. [1]
3. Plant drought-tolerant fodder crops or fodder trees (e.g. leucaena, mulberry) that stay green longer into the dry season.
4. Provide urea-molasses blocks, which improve rumen function and the digestibility of dry roughage.

(e) Why water intake increases on dry roughage [1]

Dry roughage absorbs water in the digestive tract, and the animal needs more water to soften and digest the dry feed. [1] Fresh green forage already contains 60-80% moisture, but crop residues may contain less than 15%, so the animal must drink substantially more to compensate.

(f) One vitamin important for young kids [1]

Any one of: vitamin A (for growth, immune function, and vision), vitamin D (for calcium absorption and bone development), or vitamin E (for muscle development and antioxidant protection). [1]