(a)(i) Write in detail about milk and meat borne diseases and their control. (10 marks) (a)(ii) Discuss in detail the vetero…

(a)(i) Milk-borne and Meat-borne Diseases and Their Control

Milk-borne diseases arise from pathogens shed into milk by infected animals (udder infection or systemic disease) or introduced during milking and handling:

1. Bovine tuberculosis (Mycobacterium bovis): cervical lymphadenitis and extra-pulmonary tuberculosis in humans.
2. Brucellosis (Brucella abortus, B. melitensis): undulant fever and joint pain in humans; abortion in animals.
3. Q fever (Coxiella burnetii), listeriosis (Listeria monocytogenes, dangerous in pregnancy), salmonellosis, campylobacteriosis, and Shiga-toxin-producing E. coli (haemolytic uraemic syndrome).
4. Intoxications from staphylococcal enterotoxin and Bacillus cereus.

Control of milk-borne disease: testing and control of tuberculosis, brucellosis (vaccination of calves under the National Animal Disease Control Programme) and mastitis; clean milking, cooling milk to below 4°C, and hygienic transport; pasteurisation (HTST 72°C for 15 seconds, or LTLT 63°C for 30 minutes) or boiling before consumption; avoiding raw-milk products; screening for antibiotic residues; and HACCP-based controls under the FSS Act, 2006.

Meat-borne diseases:

1. Parasitic: taeniasis and cysticercosis (Taenia saginata from beef, T. solium from pork, the latter causing neurocysticercosis), trichinellosis (Trichinella spiralis), toxoplasmosis and sarcocystosis.
2. Bacterial: salmonellosis, campylobacteriosis, E. coli O157:H7, Yersinia enterocolitica, Clostridium perfringens, botulism, and anthrax from meat of animals that died of the disease.
3. Prion: variant Creutzfeldt–Jakob disease linked to BSE.

Control of meat-borne disease: ante-mortem and post-mortem inspection in licensed slaughterhouses (never slaughtering animals that died or are anthrax suspects); condemnation of affected carcasses or organs; slaughter hygiene and avoidance of gut contamination; chilling and an unbroken cold chain; freezing to kill cysts (e.g. T. saginata cysts are inactivated at –10°C for about 10 days); thorough cooking to a core temperature of about 70–75°C; deworming of pigs and sanitary disposal of human faeces; and removal of specified risk materials in BSE-risk countries.

(a)(ii) Vetero-legal Aspects of Sudden Death of a Cow

Sudden death of a cow often becomes a legal matter because of suspected poisoning or malicious killing, disputes between neighbours, insurance claims, and claims against sellers, transporters or a veterinarian for negligence.

Legal framework: killing or maiming an animal, including by poisoning, is mischief under Section 325 of the Bharatiya Nyaya Sanhita, 2023 (formerly Sections 428–429 of the IPC); cruelty, including neglect and lack of food and water, is an offence under Section 11 of the Prevention of Cruelty to Animals Act, 1960; state cattle preservation laws may apply to cow slaughter; investigation proceeds under the Bharatiya Nagarik Suraksha Sanhita, 2023; and under Section 39 of the Bharatiya Sakshya Adhiniyam, 2023 (formerly Section 45 of the Indian Evidence Act) the veterinarian's opinion is admissible as expert evidence, although the court weighs it with other evidence.

Role of the veterinarian:

1. Post-mortem examination on a written requisition from police, a magistrate or the insurer, after identifying the carcass (ear tag, colour, markings) and recording the time of death.
2. If anthrax is suspected (sudden death, bleeding from natural orifices, absence of rigor mortis), the carcass must not be opened; a blood smear is examined and the carcass is disposed of safely.
3. Examination to establish cause of death, distinguishing natural causes (haemorrhagic septicaemia, black quarter, bloat, hypomagnesaemia, snake bite) from lightning or electrocution and from poisoning (cyanide, nitrate, organophosphates, urea, arsenic, oleander).
4. Collection of viscera for toxicology: stomach and rumen contents, liver, kidney, blood and suspect feed, each in separate clean sealed containers, preserved in saturated common salt solution or refrigerated (not in formalin), with a control sample of the preservative.
5. Chain of custody: sealing, labelling, a sample-forwarding letter and dispatch through the police to the State Forensic Science Laboratory, with signatures at every transfer.
6. A clear written report with findings and an opinion on the cause and approximate time of death, and appearance in court as an expert witness when summoned.

(b) Manufacture of Mother Starter and Bulk Starter

Starters are active cultures of lactic acid bacteria: mesophilic (Lactococcus lactis subsp. lactis and cremoris, with Leuconostoc or diacetyl-producing strains for flavour, used for dahi, cheese and butter) or thermophilic (Streptococcus thermophilus with Lactobacillus delbrueckii subsp. bulgaricus for yoghurt).

Mother starter: good-quality skim milk or reconstituted skim milk powder, tested free of antibiotic residues, is sterilised in small bottles or flasks (121°C for 15 minutes, or steamed at about 90°C for 30–60 minutes on successive days). It is cooled to the incubation temperature and inoculated aseptically with about 1% of a pure (commonly freeze-dried) culture. Mesophilic cultures are incubated at 21–22°C for 16–18 hours, and thermophilic cultures at 42–43°C for 3–4 hours, until a firm curd forms with about 0.8–0.9% acidity. The mother starter is cooled to 4–5°C and transferred daily to maintain activity; it is handled in a separate culture room with sterile pipettes.

Intermediate and bulk starter: mother starter (1–2%) is used to inoculate an intermediate starter, which in turn inoculates the bulk starter in a closed, jacketed, stainless-steel starter tank. The milk is heated to 90–95°C for 30–60 minutes, cooled to incubation temperature, inoculated, gently mixed and then incubated without agitation (to avoid wheying off). When the required acidity is reached, the starter is cooled to 4–5°C and used within a day, usually at 1–2% of cheese milk. Many plants now use frozen or freeze-dried direct-to-vat set (DVS) cultures, which avoid daily transfers.

Defects in starters and their prevention:

1. Slow or no acid production: caused by bacteriophage attack, antibiotic residues or sanitiser residues in milk, weak or over-ripened culture, or wrong incubation temperature. Prevented by phage-resistant strains and rotation of cultures, phage-inhibitory media (phosphate or citrate), heat treatment of starter milk, antibiotic screening, rinsing equipment free of sanitiser, and correct temperature.
2. Off-flavours (unclean, yeasty, malty, bitter): contamination with coliforms, yeasts or other organisms, or proteolytic strains. Prevented by aseptic transfer, sterile media, filtered air in the culture room, routine purity checks (microscopy, coliform test) and use of non-bitter strains.
3. Lack of flavour (low diacetyl) or over-acid flavour: imbalance between acid- and flavour-producing strains, or over-incubation. Prevented by correct incubation time and temperature and periodic renewal of the culture.
4. Whey separation, gassiness or ropiness: agitation during coagulation, gas-forming contaminants or ropy strains. Prevented by quiescent incubation and culture purity.

(c) FSSAI Standards for Egg Products

The standards are in Regulation 2.5.3 (Egg and Egg Products) of the Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011. Weight-based grading of table eggs is done separately under AGMARK.

Fresh eggs (2.5.3.1): unwashed, not dry-cleaned eggs collected at least once a week, with a clean, sound shell free from cracks, leaks and faecal contamination. The whole egg contents fall within specified ranges: water 68.2–76.4%, protein 12.5–14.3%, fat 10.5–15.0%, carbohydrate 0.3–1.3% and ash 0.7–1.4%. Eggs should be consumed within about 2 weeks at ambient temperature (30 ± 5°C) or 5 weeks under refrigeration (2–8°C).

Frozen egg products (2.5.3.2): frozen whole egg, yolk or albumen made from pasteurised liquid egg (pasteurisation at 61–63°C for about 5 minutes) and frozen at –23.3°C to –40°C. Minimum solids are 22.0% for whole egg, 40.0% for yolk and 10.5% for white; minimum fat is 9.8% (whole egg) and 25.0% (yolk); minimum protein is 10.5% (whole egg), 15.0% (yolk) and 10.0% (white). Indicators of spoilage are limited (β-hydroxybutyric acid not more than 10 mg/kg, lactic acid not more than 1,000 mg/kg, succinic acid not more than 25 mg/kg), and extraneous matter is restricted (no particle over 1 mm in 100 g, and not more than 100 mg/kg).

Whole egg powder (2.5.3.3): made by drying pasteurised, desugarised liquid whole egg. It must have at least 95.0% total solids, not more than 2.0% moisture, at least 41.2% lipid and at least 45.0% protein.

All egg products must also meet the microbiological requirements of Appendix B, including criteria for pathogens such as Salmonella, and the general labelling and packaging regulations.