Productive Programming in a Farrow-to-Finish Swine Operation
A closed-cycle swine farm integrates all production stages: breeding, farrowing, weaning (nursery), and finishing. The sow's complete production cycle spans approximately 20-22 weeks. From breeding to farrowing takes 16-17 weeks of gestation, followed by 3-4 weeks of lactation in farrowing crates.
ANIMAL PRODUCTION
6/24/20254 min read
A closed-cycle swine farm integrates all production stages: breeding, farrowing, weaning (nursery), and finishing. The sow's complete production cycle spans approximately 20-22 weeks (1). From breeding to farrowing takes 16-17 weeks of gestation, followed by 3-4 weeks of lactation in farrowing crates (2). Piglets are weaned at 21-28 days of age, with sows returning to estrus within ~1 week post-weaning (2). This system defines pig flow: each weaned piglet spends 5-7 weeks in nursery/transition and 14-15 weeks in finishing (3) until reaching 100-115 kg (23-25 weeks total age). The sow's complete reproductive cycle (breeding-post-weaning estrus) is ~21 days; gestation lasts ~114 days, and the wean-to-estrus interval typically ranges 3-7 days (4,5).
Production Stages
Gestation (breeding-farrowing): Lasts ~114 days (16-17 weeks) (2). On farms, sows in heat are inseminated, typically with a repeat breeding 24-36 hours later. After farrowing, sows begin lactation in farrowing rooms.
Farrowing and Lactation: Sows occupy farrowing crates with litters for 3-4 weeks (21-28 days) (2). During lactation, piglets are fed to reach 5-8 kg at weaning. Weaning age (21 vs. 28 days) depends on farm system and production goals (6).
Weaning and Nursery (transition): Post-weaning, piglets enter nursery facilities for 5-7 weeks (3) until reaching ~18-25 kg. This phase typically uses all-in/all-out (AIAO) management with strict climate/nutrition protocols to ensure health and growth.
Finishing: Pigs then move to finishing barns for 14-15 weeks (3) until reaching 100-115 kg market weight. Exact duration depends on target slaughter weight.
Each phase requires specialized facilities (farrowing crates, nursery rooms, finishing pens) with appropriate space allowances. Optimizing weaning age (e.g., 21-28 days) helps synchronize pig flow, as early weaning may compromise piglet health while late weaning reduces annual cycles (2,6).
Batch Management: Continuous vs. Batch Flow
The breeding program organizes sows into homogeneous groups (batches) bred, farrowed, and weaned within close intervals (7). Depending on interval between batches (weekly, 2-, 3-, 4-, or 5-week systems), operations use weekly or multi-week batch management (8). Batch systems offer organizational (group tasks) and health advantages by concentrating farrowings and allowing complete facility cleaning/disinfection between groups (9).
Batch programming formula:
"Number of batches = Total reproductive cycle (days) / Batch interval (days)"
Lactation length is the variable parameter (10). For planning, calculate how many batches fit within the complete reproductive cycle. Example: With 4-week lactation in a 21-week total cycle, 5 batches rotate continuously. In practice, batch intervals balance group size (sows per farrowing room) with available infrastructure.
Small herds may use continuous flow ("all-in, all-out"), but modern farms prefer strict batch systems. Continuous flow mixes age groups and complicates cleaning, increasing health risks. AIAO systems fill each barn with one uniform group, then completely empty and sanitize before repopulating, breaking pathogen transmission chains (11).
Farrowing and Weaning Scheduling
The reproductive program determines how many sows farrow weekly or every n weeks. A key goal is complete farrowing batches (filling all farrowing crates) per cycle. Thus, breedings are scheduled on fixed days (e.g., every Monday) to concentrate farrowings (avoiding weekends) (12). For example, all sows weaned on Thursday will return to estrus together within 4-6 days (5), simplifying heat detection and AI to a single session.
Fixed weaning age (21 or 28 days) determines subsequent breeding schedules (6). Example: In a 3-week AIAO weaning system, one batch is weaned every 21 days and bred 4-5 days later; after 16 weeks, the same batch farrows again. Group weaning (single weekly weaning day) synchronizes cycles for constant piglet flow. Repeat breeders (non-pregnant sows) recycle in ~21 days and must be properly reintegrated to maintain flow.
Facility Design and Sizing
Facility layouts are based on animal flow and expected production rates. Each phase must accommodate peak animal numbers simultaneously. Key criteria:
Farrowing Rooms: Number of crates equals simultaneous farrowings. Calculated as: weekly farrowings × (weeks of lactation). Example: A 120-crate farm may organize as:
Weekly management: 4-5 farrowing rooms (e.g., 4×30 or 5×24 crates) for ~30 weekly farrowings (13).
Biweekly batches: 2 rooms of 60 crates each (14).
4-5 week batches: 1 room of 120 crates (15).
Each sow requires 2.5-3.0 m² (metal crate with comfortable bedding).
Gestation: Pens or stalls are sized by density. EU standards recommend ≥2.25 m²/gestating sow (16). Group housing may reduce this to ~2.0 m² (gilts post-breeding: ~1.64 m²) (16).
Nursery: Houses weaned piglets (4-25 kg) in small pens (20-30 pigs/pen) with slatted floors. Space requirements:
<10 kg: ~0.15 m²/pig
10-20 kg: ~0.20 m²/pig (17).
Finishing: Pens hold growing pigs (25-100+ kg) in larger groups. Minimum space by live weight:
30-50 kg: ~0.40 m²
50-85 kg: ~0.55 m²
85-110 kg: ~0.65 m² (17).
Each pen typically holds 20-50 pigs.
Facilities should follow linear flow (gestation → farrowing → nursery → finishing), with quarantine areas for gilts (3-5 week acclimation). All barns should operate under AIAO to minimize age mixing.
Rotation and Space Optimization
For maximum efficiency, strictly synchronize sow movement through stages. Example: In a 5-week batch system, weaning at 21 days creates a ~20-week reproductive cycle (16.5 + 3 + 0.5 weeks), divisible by 5 (18). Thus, 4 batches operate in parallel - as one batch enters farrowing, another exits 5 weeks later, maintaining constant occupancy.
AIAO in nursery and finishing breaks the pathogen cycles of continuous flow (11). Group weaning (single weekly weaning day) induces synchronized estrus 4-6 days post-weaning (5), enabling complete batch breeding in two services (at onset and 24h after estrus).
Finally, ensure complete farrowing batches (e.g., maintain extra gilts to cover pregnancy failures) (19). Continuous replacement (40-50%/year) must be scheduled to avoid disrupting farrowing rhythm. With rigorous flow and proper facility rotation, space utilization is optimized, stabilizing annual piglet output.
Sources: Phase durations and flowcharts (2,3); reproductive management (5,18); batch systems (7,9); facility sizing (11,13, 16, 17).
(1, 2, 3, 4) produccion-animal.com.ar
(5) Manejo de la reproducción en cerdos - Manejo y nutrición - Manual de veterinaria de Merck
https://www.merckvetmanual.com/es-us/manejo-y-nutrici%C3%B3n/manejo-de-la-reproducci%C3%B3n-cerdos/manejo-de- la-reproducci%C3%B3n-en-cerdos
(6) Destetes de 21 o 28 días, ¿Cómo incide en los lechones?
https://porcinews.com/destetes-de-21-o-28-dias-como-incide-en-los-lechones/
(7, 8, 10, 13, 14, 15) Manejo en bandas. ¿Mi granja funciona correctamente? Los principios del manejo en bandas – Plataforma de Servicios Ceva para Porcino
(9) Manejo en bandas porcino: ¿Cómo pasar de un sistema de bandas semanal a bandas superiores a una semana?
https://swinehealth.ceva.com/es/blog/manejo-en-bandas-porcino
(11) PORCICULTURA: El valor del sistema todo dentro/todo fuera y destete temprano
https://www.produccion-animal.com.ar/produccion_porcina/00-produccion_porcina_general/38- importancia_enfermedades.pdf
(12) Gestión del objetivo de partos para lograr una edad destete óptima (I) - Artículos - 3tres3 LATAM, la
página del Cerdo
(16, 17) DIMENSIONAMIENTO DE EXPLOTACIONES
https://www.avparagon.com/pdfs/documentos/instalaciones/CCANTIN_DIMENSIONAMIENTO.pdf
(18) Aplicación del manejo en bandas cada 5 semanas en explotaciones con po - Artículos - 3tres3
LATAM, la página del Cerdo
(19) Microsoft Word - 510 Scheduling Pig Flow.doc
https://www.ipic.iastate.edu/publications/510.schedulingpigflow.pdf
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