Productive Parameters in Sheep Farming: Meat, Milk, and Wool
Sheep farming is a versatile livestock activity that produces meat, milk, and wool (in addition to hide and manure). Unlike other species, sheep utilize diverse pastures and marginal lands, require low investment in infrastructure and minimal personnel, and provide multiple products in relatively short cycles.
ANIMAL PRODUCTION
7/22/20256 min read
Sheep farming is a versatile livestock activity that produces meat, milk, and wool (in addition to hide and manure). Unlike other species, sheep utilize diverse pastures and marginal lands, require low investment in infrastructure and minimal personnel, and provide multiple products in relatively short cycles (1). Various zootechnical parameters are used to assess their efficiency: weight gain, feed conversion, carcass yield, age at first lambing, lambing interval, prolificacy, milk production, and wool quality. These indicators are described below and illustrated with examples from representative breeds.
Meat Production: Gain, Conversion, and Carcass
Average Daily Gain (ADG): Indicates how much weight a lamb gains on average per day during fattening. For meat breeds, values of 250–350 g/day are expected. For example, Merino lambs in Spain typically reach ~300 g/day (2). Lamb fattening is considered profitable if the ADG exceeds 300 g/day (3). Highly specialized meat breeds (e.g., Hampshire Down, Dorper) can exceed 350 g/day, while very hardy breeds or those under extensive grazing are in the lower range.
Feed Conversion Ratio (FCR): This is the amount of feed consumed per kg of weight gained. In fattening sheep, it usually ranges from 4–6 kg of feed per kg of gain. Optimal values are lower (e.g., <5) in wool breeds or under intensive management, and higher (6–8) in very hardy grazing lambs. In general, efficiency is lower than in pigs but comparable to cattle, given the smaller size of sheep and their ability to utilize low-quality forages.
Carcass Yield: This is the percentage that the carcass weight (hot or cold) represents relative to the pre-slaughter live weight. In sheep, it is usually close to 50%. For example, in young Merinos weighing ~25–35 kg live, a carcass yield of ~49–51% is reported (4). Generally, sheep carcasses have about 45–50% yield (5), similar to cattle (50–55%) and goats. Lamb meat is usually tender and mild in flavor.
Key Reproductive Parameters
Age at First Lambing: Ideally, ewes have their first lambing between 12 and 14 months of age (6). This means the ewe is bred during her first estrus (6–8 months of age) and lambs around one year old. In demanding situations, it can be brought forward, but very early ages can hinder bodily development. In less intensive systems, however, it is common for the first lambing to occur between 16–24 months.
Lambing Interval: Typically, this is 8 to 12 months. In conventional autumn-spring management, ewes lamb once a year (interval ≈12 months). Accelerated systems aim for one lambing every ~8 months (3 lambings in 2 years) (7), by utilizing out-of-season estrus, to increase annual meat production.
Prolificacy (Lambs per Lambing): Varies by breed and management. In wool breeds like Merino sheep, it is low to moderate (~1.2 lambs per lambing) (8); in meat breeds or crosses, the average can be 1.5–2 (many twin lambs). On average, a Merino ewe produces 1.2 lambings/year with ~1.4 lambs per lambing (8). Ewes usually give birth to one or two lambs; this is more than cows (1 calf) and less than some specialized dairy goats.
Fertility and Weaning: Ovulation and weaning rates are usually high (70–90%) if feeding management is adequate. For example, adult ewes are expected to have 95–100% fertility during the fertile season (6). However, lamb losses (stillbirths, pre-weaning mortality) reduce effective production.
Milk Production
Sheep's milk is primarily used for fine cheeses (Manchego, Pecorino, etc.). The relevant parameters are production per lactation, lactation length, and milk composition.
Milk Production: Dairy sheep breeds (e.g., Manchega, Lacaune, Assaf) are specialized for high yields, though they are a minority. In wool breeds like Merino, ~275 kg of milk per lactation are reported (9). This is equivalent to ~5–6 L/day during 150–180 days of lactation. Intensive dairy sheep can exceed 300–400 kg/lactation.
Milk Quality: Sheep's milk is very rich in solids. It contains ~17.6% dry matter, with 6.5% fat and 5.4% protein (10). These values significantly exceed those of cow's milk (13.5% DM, 4.8% fat, 3.2% protein) (10) and goat's milk (14.2% DM, 4.9% fat, 4.3% protein). This makes it ideal for high-quality cheeses with low whey volume. For comparison:
% Total Solids: Sheep (17.6%), Goat (14.2%), and Cow (13.5%).
% Fat: Sheep (6.5%), Goat (4.9%), and Cow (4.8%).
% Protein: Sheep (5.4%), Goat (4.3%), and Cow (3.2%).
All these data come from typical analyses of sheep, goat, and cow milk (10).
Wool and Fiber Production
For sheep raised for wool (e.g., Merino, Corriedale), the parameters of interest are the wool weight per shear and its quality (micronage). For example, in Merino ewes, the average fleece weight per annual shear is ~3.4 kg for females and ~5.2 kg for males (11). The fiber is very fine (average Merino ~20.5 micrometers in diameter) (12) and of uniform medium length. These characteristics define high-quality fine wool. In contrast, hair or meat breeds (e.g., Dorper, Pelibuey) produce practically no usable wool.
In addition to fineness and weight, clean yield (proportion of useful fiber after degreasing) and uniform fleece length are evaluated. Wool productivity adds to the sheep's income but is usually secondary to meat or milk, except in traditional wool-producing regions.
Comparisons with Bovine and Caprine Livestock
Sheep have productive characteristics intermediate between cattle and goats: smaller animals (50–80 kg), mature faster (1–1.5 years vs. 2–3 in bovines), and have a short gestation period (~5 months, same as goats). Compared to cattle, sheep achieve lower weights and per-head production but can reproduce more times a year and have multiple offspring. Compared to goats, both species share hardiness and dual purpose, but sheep provide wool as a byproduct. For example, while a dairy cow raises 1 calf/year, a sheep can lamb 1–2 lambs/year (6, 8).
In terms of weight gain, sheep fatten faster than most goats but slower than beef cattle (except for highly specialized meat breeds). The table above illustrated that sheep's milk is more concentrated than goat's or cow's milk (10).
Advantages and Challenges of Sheep Farming
Sheep farming presents several competitive advantages (1):
Low Investment and Labor: Requires simple facilities (pen, shade) and minimal personnel (1).
Adaptability: Can utilize diverse pastures and rugged terrain, even in transhumance or extensive systems (13).
Multiple and Rapid Products: Within 6 months, a sheep can generate meat (lambs) and wool, adding value with manure and by-products (hide, lanolin) (14).
Commercial Versatility: By providing meat, milk, and fiber, it allows for market diversification and risk reduction.
Among the challenges are: reproductive seasonality (most breeds cycle in autumn, fixing lambing cycles), losses due to parasites or diseases (gastrointestinal larvae, brucellosis, etc.), volatility of meat and wool prices, and competition with other meats in markets where demand for sheep meat is low. Additionally, the low average productive scale in many countries hinders technification. To be sustainable, systems must optimize health, feeding, and genetics (focused on infertility, prolificacy, wool/milk quality) and secure differentiated markets (artisan cheeses, fine wools, value-added lambs).
Regional Examples of Productive Parameters
Spain (Merino): Under traditional conditions, Merino lambs achieve ~300 g/day of gain (2). Live weight at slaughter is typically 24–28 kg (carcass ≈49% of live weight) (4), and each adult ewe produces ~3.4 kg of fine wool per year (males ~5.2 kg) (11).
Argentina: With a wool-producing heritage, more than 50% of the national sheep inventory consists of Merino or Corriedale breeds (fine wool/dual purpose) (15). Productive parameters similar to European Merinos are reported there, with an average prolificacy of ~1.4 lambs/lambing (8) and wool yields of several kilograms per animal.
Mexico and Central America (Pelibuey): Hardy hair sheep adapted to the tropics predominate (16). The Pelibuey, for example, does not grow wool and is very prolific (lambs almost year-round), although its weight gains are lower than those of European breeds. It is mainly raised for meat (and valuable manure) in hot, extensive systems (16).
Australia: World leader in wool production (fine Merino). There, Merino sheep show fattening parameters comparable to Spanish ones (ADG ~300–350 g/day in intensive systems) and shear ultra-fine wool (15–17 µm).
Collectively, productive data vary by breed, climate, and management but illustrate the differences between systems. Based on these parameters, farmers and technicians can compare the efficiency of their sheep against standards and other species, and thus make decisions to improve the profitability and sustainability of sheep farming.
Sources: Data compiled from technical manuals and studies on sheep breeds (1, 3, 6, 10, 15, 16, 17). Each cited figure corresponds to specialized references in sheep farming.
(1, 5, 10, 13, 14) Microsoft Word - TextoOvino-Caprino2.doc
https://cenida.una.edu.ni/textos/nl01s127o.pdf
(2, 4, 8, 9, 11, 12, 17) Raza ovina MERINA
(3) mla.com.au
(6, 7) Medición del rendimiento reproductivo de las ovejas - Manejo y nutrición - Manual de veterinaria de MSD
https://www.msdvetmanual.com/es/manejo-y-nutrici%C3%B3n/manejo-de-la-reproducci%C3%B3n-ovejas/medici%C3%B3n- del-rendimiento-reproductivo-de-las-ovejas
(15) Ovinos - Producción Primaria | Argentina.gob.ar
(16) Pelibuey - Wikipedia, la enciclopedia libre
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