Commercial pigs are specifically bred and raised for meat within structured agricultural systems designed for efficiency. These animals are distinct from their wild ancestors or those kept as pets. Pork accounts for a significant portion of worldwide meat consumption. Production is segmented into specialized phases, including breeding, farrowing (birth), nursery, and finishing stages, each with a specific operational focus.
Dominant Breeds and Genetic Selection
Modern pork production relies on select breeds chosen for superior genetic traits, such as the Yorkshire, Landrace, Duroc, and Hampshire. Yorkshire and Landrace are selected for maternal characteristics, including large litter sizes and mothering abilities. Crossbreeding these “dam lines” is a common practice to take advantage of hybrid vigor, resulting in offspring with enhanced reproductive performance.
Terminal sire lines, such as Duroc or Hampshire, are selected for traits related to growth and carcass quality. These breeds are known for rapid growth rates, efficient feed conversion, and a high percentage of lean meat. Genetic selection programs focus on improving these economically important traits, which have heritability estimates from 30% to 50%.
Continuous genetic improvement is achieved through performance testing and artificial insemination, which allows for the widespread dissemination of desirable genes. While reproductive traits like litter size have lower heritability at around 10%, consistent selection pressure has still led to significant gains.
Housing Systems and Environmental Management
Commercial pigs are raised in indoor facilities designed to control environmental conditions and optimize production. Farrowing units provide a protected environment for sows and their newborn piglets, often using crates to prevent the sow from crushing the young. After weaning, piglets are moved to nurseries and then to grower-finisher pens.
Ventilation systems maintain air quality by removing noxious gases like ammonia and dust. Temperature control is also managed, as pigs have different thermal needs at various stages. For instance, newborn piglets require a much warmer environment than finishing hogs and often need supplemental heat sources like heat lamps or heated mats.
Slatted floors are commonly used to allow for efficient waste removal and to keep the animals clean. Space allocation is regulated to ensure pigs have enough room to move and lie down comfortably. Waste management is a significant aspect of these operations, with many farms using the collected manure as fertilizer for cropland.
Nutritional Strategies for Commercial Production
The diets of commercial pigs are scientifically formulated to meet nutritional needs at each stage of growth. These feeds are based on cereal grains like corn and wheat for energy and protein sources such as soybean meal. The diet is balanced to provide the necessary amino acids, vitamins, and minerals.
Nutritional requirements change significantly as a pig matures. Starter diets for newly weaned pigs are highly digestible and nutrient-dense to support the transition from sow’s milk. Grower and finisher diets are formulated to promote lean muscle growth and efficient weight gain, while sows have specialized diets for gestation and lactation.
Various supplements and additives may be included to enhance feed efficiency and promote health. Crystalline amino acids are used to meet protein requirements while reducing excess nitrogen excretion. Some diets include products like spray-dried plasma to encourage feed intake in young pigs, and pelleting feed can improve efficiency.
Health Protocols and Animal Welfare Standards
Maintaining herd health involves comprehensive biosecurity measures, vaccination programs, and routine veterinary care. Biosecurity protocols are designed to prevent the introduction and spread of diseases. Common health challenges include respiratory and enteric diseases, managed through vaccination and environmental control. Staff inspect pigs daily to identify any signs of illness or injury for prompt treatment.
Animal welfare is a consideration in pig farming, with standards established by industry bodies and government regulations. These standards address various aspects of a pig’s life, including housing, handling, and health. The “Five Freedoms” of animal welfare serve as a guiding framework, covering freedom from hunger, thirst, discomfort, pain, injury, disease, fear, and distress, plus the freedom to express normal behavior.
Practices like tail docking and teeth clipping are performed to prevent injuries from aggression in group-housed animals. Research into alternative practices and housing systems aims to improve welfare. Environmental enrichment, such as providing straw for rooting, allows pigs to express natural behaviors. Some systems are also moving from gestation crates for sows towards group housing to address welfare concerns.