(a) Mention the steps involved in cryopreservation of bull semen. (10 marks) (b) Discuss the points to be considered during care…

(a) Cryopreservation of Bull Semen

1. Collection: semen is collected with an artificial vagina (electro-ejaculation only for bulls that cannot mount), usually twice a week with two ejaculates per collection day.
2. Evaluation: volume, colour, concentration (by photometer) and mass activity (at least +3) are checked; ejaculates with initial progressive motility of at least 70% are accepted.
3. Dilution (extension): semen is diluted at 30–35°C in Tris–citric acid–fructose–egg yolk extender (or an egg-yolk-free soya lecithin extender) containing about 6–7% glycerol as cryoprotectant and antibiotics (gentamicin, tylosin, lincomycin–spectinomycin), to give 20 million sperm per dose.
4. Filling and sealing: extended semen is filled into 0.25 mL French mini-straws, sealed and printed with bull and batch details.
5. Cooling and equilibration: straws are cooled slowly to 4–5°C and held for about 3–4 hours so that glycerol equilibrates across sperm membranes.
6. Freezing: straws are frozen in a programmable biological freezer, or in liquid nitrogen vapour about 4 cm above the liquid for about 10 minutes, and then plunged into liquid nitrogen at −196°C.
7. Post-thaw check and storage: a sample straw is thawed at 37°C for 30 seconds; batches with at least 50% post-thaw motility are stored in liquid nitrogen containers and distributed for artificial insemination.

In India these steps follow the Minimum Standard Protocol for semen stations of the Department of Animal Husbandry and Dairying.

(b) Care and Management of the Neonatal Calf

• At birth: clear mucus from the nose and mouth, rub the calf with clean straw or let the dam lick it to stimulate breathing and circulation, and see that it stands and suckles.
• Navel care: cut the cord about 5 cm from the body with a clean instrument (tie it only if it bleeds) and dip it in 7% tincture of iodine, repeating for 2–3 days, to prevent navel ill and joint ill.
• Colostrum: the most important point. The first feed should be given within one to two hours of birth, because the gut absorbs antibodies best in the first 6 hours and gut closure is nearly complete by 24 hours; about 10% of body weight should be fed on the first day, and good colostrum has more than 50 g/L of IgG.
• Feeding after colostrum: whole milk at about one-tenth of body weight a day, with calf starter (about 20–22% crude protein) and good hay from the second week to develop the rumen.
• Housing and hygiene: clean, dry, well-bedded, draught-free individual pens for the first weeks, protection from cold and heat, and clean feeding utensils.
• Identification and records: ear tag (Pashu Aadhaar) and record birth weight, dam and sire.
• Health care: deworm against Toxocara vitulorum at about 10 days and again at 3 weeks (especially buffalo calves); disbud at 1–2 weeks; watch for calf scours, pneumonia and navel ill; vaccinate from about 4 months of age (FMD, haemorrhagic septicaemia, black quarter; brucellosis for female calves at 4–8 months).
• Weaning: gradual, once the calf eats about 1 kg of starter a day.

(c) Characteristics of Gir and Sahiwal Cattle Gir: the home tract is the Gir forest region of Saurashtra, Gujarat (Junagadh, Amreli, Bhavnagar and Rajkot). It has a prominent, convex forehead, long pendulous ears folded like a leaf with a notch at the tip, and curled horns that turn back and then up, giving a half-moon look. The coat ranges from red to spotted red and white; the skin is loose and pliable, and bulls have a large hump. Cows weigh about 380–400 kg and bulls 550–600 kg. Average lactation yield is about 1,500–2,500 kg, with elite cows over 3,000 kg, and milk fat is about 4.5–5%. The breed is hardy and heat- and tick-tolerant, and has been used abroad, notably in Brazil, where Gir × Holstein crosses form the Girolando.

Sahiwal: it originated in the Montgomery (now Sahiwal) district of Punjab, Pakistan; in India it is found in Punjab, Haryana and the Rajasthan border areas. The colour is reddish dun or pale red, sometimes with white patches; the skin is loose (hence the local name "Lola"), with a heavy dewlap, short stumpy horns, a massive hump in bulls and a large, well-attached udder in cows. Cows weigh about 350–450 kg and bulls 500–600 kg. It is the best indigenous dairy breed, averaging about 2,000–3,000 kg per lactation with 4.5–5% fat, and is heat- and tick-tolerant. It is a parent of the crossbreds Frieswal (Holstein-Friesian × Sahiwal) and Karan Swiss (Brown Swiss × Sahiwal), and abroad of the Australian Milking Zebu and Jamaica Hope.

Both breeds are conserved and improved under the Rashtriya Gokul Mission.

(d) Feeding Strategies of Goats for Chevon Production

• Kid stage: colostrum within the first hour, then the dam's milk; creep feed (about 18–20% crude protein) and tender leaves from 2–3 weeks, so that kids are weaned at about 3 months without a check in growth.
• Growing and finishing: meat kids need energy-dense rations for fast gain. In the semi-intensive system (6–8 hours of grazing and browsing) they receive 150–300 g of concentrate a day (14–16% crude protein, about 70% TDN). In stall-fed (intensive) finishing, a roughage-to-concentrate ratio of about 50:50 or 40:60, or complete feed blocks, gives daily gains of 80–120 g in breeds such as Sirohi, Barbari and Jamunapari, and more in Boer crosses. Kids are usually marketed at 6–9 months and 18–25 kg.
• Protein sources: groundnut, soybean or mustard cake in the concentrate, and tree leaves and pods such as subabul (kept below about 30% of the diet because of mimosine), ber, neem, pipal and Prosopis pods as cheap protein.
• Minerals, salt and water: 1% mineral mixture and 1% salt in the concentrate, and clean water always available. Male kids on concentrates need a Ca:P ratio of about 2:1 and, where needed, 0.5–1% ammonium chloride to prevent urinary calculi.
• Health-linked feeding: introduce grain gradually and vaccinate against enterotoxaemia to prevent acidosis and pulpy kidney disease; regular deworming improves feed efficiency.
• Feeding frequency: concentrates in two meals and roughage several times a day, offered in raised racks to reduce wastage.

(e) Breeding System for Pig Production in India

• Pure breeding of exotic breeds (Large White Yorkshire, Landrace, Hampshire and Duroc) at government and university farms supplies boars and gilts, while registered indigenous breeds such as Ghungroo (West Bengal), Niang Megha (Meghalaya), Doom (Assam), Tenyi Vo (Nagaland) and Mali (Tripura) are conserved for hardiness and local adaptation.
• Crossbreeding, the main commercial system, exploits heterosis in litter size, piglet survival and growth. Common schemes are two-breed crosses (Large White × Landrace F1 sows), three-breed terminal crosses (F1 sows mated to Duroc or Hampshire boars, with all offspring sold for meat) and rotational crossing in smaller herds.
• Grading up of desi pigs with exotic boars suits backyard systems in the North-East, Jharkhand and Kerala. Crossbred varieties have been released, such as Rani (Hampshire × Ghungroo, 50:50) and Asha (Duroc × Rani) from ICAR–National Research Centre on Pig, and Jharsuk (Tamworth × desi) from Birsa Agricultural University.
• Selection of boars and gilts is for growth rate (age at 90 kg), feed efficiency, backfat thickness, litter size at birth and weaning, and number of teats.
• Artificial insemination uses mainly liquid semen stored at 15–18°C for 3–5 days, since frozen boar semen gives poor fertility; it spreads superior boars to small farmers and reduces disease transmission.
• These programmes are coordinated through the All India Coordinated Research Project on Pig, led by ICAR–National Research Centre on Pig, Guwahati, with breeder-farm support under the National Livestock Mission.