(a) Worsted system of wool processing (10 marks) (b) Platform tests for determination of milk quality (10 marks) (c) Occupational…

(a) Worsted System of Wool Processing The worsted system is a specialized method of wool processing designed to produce smooth, lustrous, and durable yarns, distinct from the woollen system, which cards the wool but omits combing. The process runs through scouring (and carbonising if burrs are present), carding, gilling, and a critical combing stage. Combing aligns the fibers parallel to one another and removes short fibers, known as noils, as well as impurities. This alignment ensures that the resulting sliver consists primarily of long, uniform staple lengths. The combed sliver (top) is then drawn, made into roving and spun into yarn. Because short fibers are removed, the worsted yarn has a higher twist and greater strength compared to woolen yarn, resulting in a fabric that is dense, resistant to pilling, and capable of holding a fine finish. This system is mainly used for long-staple wools, such as Merino, to manufacture fine suiting, dress fabrics, and high-end apparel. The noils are sold separately for woollen goods, while worsted yarn commands a premium.

(b) Platform Tests for Milk Quality Platform tests are rapid, field-applicable methods used at milk collection centers to assess the quality and safety of raw milk before procurement. These tests are crucial for ensuring hygiene and preventing the adulteration of the milk supply chain. The first is the organoleptic test (smell, taste, appearance), which rejects off-odour, discoloured or abnormal milk at once. The Clot on Boiling (COB) test detects developed acidity or abnormal milk (colostrum, mastitic milk) by boiling a sample; absence of clotting indicates acceptable acidity, and the alcohol or alizarin-alcohol test (mixing milk with 68% alcohol) flags milk with high acidity or poor heat stability. The Sediment Test measures physical impurities like dirt and hair, while the Specific Gravity test using a lactometer helps detect water addition or cream removal. Rapid kits detect adulterants such as starch (iodine test), cane sugar, urea and neutralisers, and fat/SNF are read on electronic milk analysers. The Methylene Blue Reduction Test (MBRT) takes hours, so it is a laboratory rather than a platform test. These tests give farmers immediate feedback and keep spoiled or adulterated milk out of the processing chain.

(c) Occupational Zoonotic Health Hazards Occupational zoonoses are infectious diseases transmitted from animals to humans through professional exposure. In the livestock sector, workers such as veterinarians, abattoir staff, and dairy handlers face significant risks. Brucellosis is a major concern, transmitted through contact with infected fluids, causing undulant fever and joint pain. Q-fever, caused by Coxiella burnetii, is often aerosol-transmitted during calving or handling placentas. Leptospirosis, a bacterial infection, is acquired through contact with urine-contaminated water or soil. Tuberculosis and rabies are also prevalent risks for those handling sick or dead animals. Anthrax is a critical hazard; while hide porters are classically at risk of cutaneous anthrax ('hide porter's disease') from handling infected hides, wool handlers are at risk of inhalational anthrax ('woolsorter's disease') from dust containing spores. Prevention requires strict adherence to personal protective equipment (PPE), including gloves, masks, and protective clothing. Vaccination programs for high-risk groups, regular health surveillance, and proper disposal of animal carcasses are essential.

(d) Preslaughter Care of Food Animals Preslaughter care is the management of animals from arrival at the abattoir until slaughter, directly impacting meat quality and animal welfare. Proper lairage management involves providing adequate space, ventilation, and shade to reduce stress. The Prevention of Cruelty to Animals (Slaughter House) Rules, 2001 require animals, after veterinary inspection, to rest in lairage for 24 hours before slaughter, allowing muscle glycogen recovery, which is crucial for preventing quality defects. Feed is typically withdrawn 12 to 24 hours before slaughter to reduce rumen fill and facilitate evisceration, while clean water is provided ad libitum to prevent dehydration. Humane handling is paramount; prolonged stress from rough handling or overcrowding depletes muscle glycogen, resulting in Dark, Firm, and Dry (DFD) meat in cattle, while acute stress just before slaughter causes rapid lactic acid buildup, producing Pale, Soft, and Exudative (PSE) meat in pigs. These defects reduce shelf life and consumer acceptance. Furthermore, preslaughter care ensures compliance with animal welfare laws, such as the Prevention of Cruelty to Animals Act, which mandates humane treatment. By minimizing stress, the meat retains its natural pH and color, enhancing its market value.

(e) Defects of Whole and Skim Milk Powder Milk powder defects arise from processing, storage, and formulation errors, affecting flavor, texture, and solubility. Common defects include browning, caused by the Maillard reaction between lactose and proteins during high-temperature processing or warm storage. Oxidised (tallowy) flavour results from lipid oxidation and is chiefly a defect of whole milk powder because of its fat, while skim milk powder suffers more from browning, stale flavour and insolubility. Oxidation is promoted by too low a preheat (which leaves fewer protective sulphydryl groups), copper or iron contamination, and exposure to light and oxygen. Scorched particles occur when milk is overheated during spray drying, causing caramelization of lactose. Caking and insolubility are major issues, where the powder clumps and fails to dissolve properly, usually due to high moisture content or improper packaging. The primary causes include excessive preheating temperatures, high residual moisture, and poor storage conditions. Prevention involves precise control of drying parameters, such as inlet and outlet temperatures, to avoid scorching. Nitrogen flushing of packaging reduces oxygen exposure, preventing oxidation. Adding antioxidants can further stabilize the product. Maintaining low moisture content and using hermetic packaging prevents caking. Regular quality control checks for acidity and fat stability are essential.