(a) Describe the procedure for calculating the economics of milk production in commercial dairy farm having five hundred (500)…

(a) Economics of Milk Production in a 500-Cow Crossbred Farm The procedure is a cost-benefit analysis for one year, with the herd of 500 as the base.

Step 1, costs.

• Fixed costs: depreciation on cows (purchase price minus salvage value, over productive life), sheds, equipment and milking machines; interest on capital; insurance; permanent staff salaries; land rent.
• Variable costs: green fodder, dry fodder, concentrate and minerals (usually 60–70% of cost); casual labour; veterinary care, AI and vaccination; electricity, water, transport; interest on working capital; miscellaneous.

Step 2, returns. Gross returns are milk (litres × farm-gate price) plus subsidiary income: sale of calves, culled animals, dung and manure.

Step 3, indicators.

• Gross cost = fixed + variable.
• Net cost = gross cost − subsidiary income.
• Cost of milk per litre = net cost ÷ litres.
• Net income = total returns − gross cost; net income per cow = net income ÷ 500.
• Benefit-cost ratio = total returns ÷ gross cost; above 1 means profit.
• Return over feed cost = gross returns − feed cost.
• Break-even yield or price, and return on investment.

Illustration (assumed values): herd average 8 L/cow/day gives 14.6 lakh L a year. At ₹40/L, milk returns are ₹5.84 crore. With by-product income of ₹0.30 crore, total returns are ₹6.14 crore. If gross cost is ₹5.20 crore, net income is ₹0.94 crore (₹18,800 per cow), net cost is ₹4.90 crore, milk costs about ₹33.6/L, and BCR is about 1.18. Use average milk per cow across lactating and dry animals, and keep records of herd composition by stage.

(b) Precision Dairy Farming and Role of AI Precision dairy farming is the use of sensors, data analysis and automation to monitor each cow continuously, in real time, for health, reproduction, feeding and milk yield, so that decisions are made for the individual animal, not the herd average.

Role of AI in livestock farming:

• Health: machine learning on activity, rumination, temperature and milk-conductivity data predicts mastitis, ketosis and metabolic disease before clinical signs.
• Reproduction: heat detection from activity data and optimal AI timing.
• Computer vision: gait scoring for lameness, body condition scoring, and behaviour and welfare analysis.
• Feeding: individual ration adjustment by yield and health.
• Robotic milking and milk quality (somatic cell count) analysis.
• Prediction of yield and culling decisions, and in poultry and fisheries, monitoring of mortality and feed. In India, e-Gopala and INAPH are herd-data platforms; AI tools are growing in breed identification and disease alerts.

(c) Sex-Linked Genes Sex-linked genes lie on the sex chromosomes: X-linked on the X, Y-linked on the Y in mammals, and Z-linked in birds. They differ from sex-influenced genes, which are autosomal but expressed differently by sex, and from sex-limited genes, which act in one sex only (such as milk yield).

Difference from autosomal inheritance:

• Autosomal genes occur in two copies in both sexes, and reciprocal crosses give the same result.
• X-linked genes are hemizygous in males (XY), so one recessive allele is expressed, and affected males outnumber females. A carrier mother passes the trait to half her sons, an affected father passes his X to all daughters but none to sons: criss-cross inheritance.
• Y-linked (holandric) genes pass only from father to son.
• In birds, the female is ZW, so Z-linked traits reverse the pattern: an affected father passes to all daughters. Barring in chickens and slow feathering are used for autosexing at hatch.
• Females have X-inactivation (dosage compensation); autosomal genes do not. Cattle have 29 pairs of autosomes (2n = 60) and one pair of sex chromosomes.