(a) Describe the methods of estimating inbreeding coefficient and breeding value of animals. (20 marks) (b) Suggest measures…

(a) Estimation of Inbreeding Coefficient and Breeding Value Inbreeding coefficient (F) is the probability that the two alleles at a locus in an individual are identical by descent.

Methods for F:

• Path coefficient (Wright): for individual X with common ancestor A, F_X = Σ (½)^(n₁+n₂+1) (1 + F_A), where n₁ and n₂ are the numbers of generations from A to the sire and the dam; sum over all paths through all common ancestors.
• Tabular (Henderson's numerator relationship matrix): the diagonal element is 1 + F, and F of an individual is half the relationship between its sire and dam, F_X = ½ a_SD. It suits large pedigrees and computers.
• Genomic: runs of homozygosity from SNP chips.

Breeding value (BV) is twice the average deviation of an animal's progeny from the population mean, or the additive genetic merit of the animal. Methods:

• Own performance: BV = h² (P − P̄), for single-record, early traits.
• Pedigree and family-based estimation, using the performance of ancestors, sibs or half-sibs, weighted by relationship and h².
• Progeny testing: BV of sire = 2n h² / [4 + (n − 1) h²] × (progeny mean − herd mean), where n is the number of progeny.
• Selection index, combining several sources and traits.
• BLUP: best linear unbiased prediction under a mixed model; the animal model uses the full relationship matrix and corrects for contemporary-group and herd effects, so animals without progeny can be compared. The sire model estimates a sire's transmitting ability, which is half BV.
• Genomic BLUP using SNP chips, which gives higher accuracy at birth. Accuracy is the correlation between true and estimated BV.

(b) Milk Production and Supply Chain During Natural Calamities Measures:

• Before: preparedness plans linked to State and District Disaster Management Plans under the Disaster Management Act, 2005; silage and hay banks and fodder seed reserves; vaccination and deworming; livestock insurance; identification and ear-tagging of animals; safe shelters on raised ground.
• During: evacuation of animals to cattle camps, with fodder, water and mobile veterinary teams; mineral mixture and electrolytes for stressed animals; hand milking and portable milking equipment; fodder transport, including by rail.
• Supply chain: backup generators, solar and chilling at Bulk Milk Coolers and Milk Chilling Centres; insulated tankers; alternate collection routes and mobile collection units; dairy cooperatives (NDDB and State Federations) to coordinate procurement, and quality testing so spoilt milk is not marketed; spray-drying for surplus milk and UHT/powder conversion.
• After: veterinary health camps for mastitis, FMD, haemorrhagic septicaemia and ketosis; disease surveillance; carcass disposal; replacement animals, credit and insurance claims for farmers; and restoration of cooperatives. Platforms like INAPH and e-Gopala help with animal records and tracking.

(c) Pedigree Selection Pedigree selection is selection of an animal on the basis of the recorded performance of its ancestors (parents, grandparents) and sometimes collateral relatives, not its own phenotype or progeny. The pedigree index weights ancestors' performance by their relationship with the candidate, and BLUP now includes it.

Process: keep pedigree and performance records; compute the average ancestral performance, or the pedigree index, for candidates; select those with the highest value as sires or dams.

Advantages: selection can be made at birth, before the animal can show its performance; useful for sex-limited traits (milk yield in bulls) and traits expressed late (longevity, lifetime production) or with low heritability; cheap and quick; and it shortens the generation interval.

Disadvantages: accuracy is lower than progeny testing since it relies on indirect information; each ancestor contributes progressively less, and accuracy falls beyond two or three generations; pedigree and recording errors and environmental differences bias the information; it ignores Mendelian sampling, the individual's own merit; and inbreeding may rise. Hence it is used mainly for early screening.