Are Smaller-Framed Cattle Really More Economical?
In recent years, a certain idea has been heavily pushed in the beef industry - that smaller-framed cows are inherently more economical. The reasoning seems straightforward: smaller animals consume less feed, so their maintenance costs should be lower. While this logic holds at face value, a deeper examination of research across multiple ruminant species - including domestic cattle, sheep, goats, and wild ruminants - paired with practical experience reveals a much more nuanced reality. Larger cows, when properly managed, often outperform smaller cows in productivity, reproductive efficiency, and long-term profitability.
On our farm, calving-age heifers typically weigh between 1,400 and 1,600 pounds at around 24 months of age, while mature cows often range from 1,600 to 1,800 pounds (with a few exceptional individuals exceeding 2,000 pounds). All cows are weighed after calving to provide a consistent measure of their full weight potential so that we can calculate an accurate weaning efficiency. These cows are not bred for size; they are selected for structural soundness, maternal reliability, and the ability to thrive on pasture without grain supplementation. One standout cow weighed 2,097 lbs on her most recent post-calving weigh-in, yet continues to rebreed on her first heat, calve unassisted, and wean the heaviest calf in the herd (with excellent weaning efficiency) every year. Our biggest cow is our most efficient? That goes against what many in the industry preach - so what’s going on? Let’s take a deeper dive to see what these studies are omitting.
Frankly, the research supports what we’ve observed, but only if you look at the overall picture and not just a snapshot. A study conducted by the Louisiana State University AgCenter compared cows averaging 1,210 lbs with those weighing around 1,377 lbs. The larger cows consumed only about two pounds more dry matter per day but weaned calves an average of 32 pounds heavier (LSU AgCenter, 2020). This demonstrates that small increases in intake can yield proportionally greater returns in weaned calf weight - particularly relevant when evaluating efficiency on a per-pound basis. After all, calves are sold by weight.
Similar findings were reported in a Nebraska Sandhills study involving over 1,600 crossbred cows. Each 100 kg (220 lbs) increase in cow weight was associated with a 2.7 kg (5.94 lbs) increase in calf birth weight and a 14.8 kg (32.5 lbs) increase in weaning weight, alongside improved average daily gain (Funston et al., 2012). While smaller cows initially showed higher feed efficiency (when considering intake relative to calf weight alone), this advantage diminished once fertility and lifetime productivity were factored in. Crucially, the study noted that smaller cows exhibited reduced fertility and lower pregnancy rates, meaning fewer calves per cow over her lifetime. This fertility limitation directly offsets any feed savings smaller cows might provide and reduces total beef production relative to inputs. This is often conveniently left out of the conversation.
Further evidence comes from feedlot trials at Kansas State University, where larger-frame steers (51–53 inch hip height) achieved higher daily gains and heavier carcass weights with better net returns than smaller-framed animals (Kansas State University, 2018). These findings mirror the conclusions of a Canadian Journal of Animal Science review, which noted that selecting for moderate-to-large-framed cattle reduces the number of animals needed to meet beef production targets, ultimately improving economic efficiency per unit of meat produced (Canadian Journal of Animal Science, 2016). This evidence shows that larger-framed cattle can efficiently produce meat at a competitive level.
A Financial Perspective
To understand the economics of cow size, let’s consider two herds of equal size, 30 cows each, but differing in mature weights. The first herd is composed of smaller-framed cows averaging about 1,200 pounds, while the second herd consists of medium to large-framed cows averaging around 1,500 pounds.
Smaller cows wean calves weighing approximately 500 pounds, while larger cows wean calves closer to 650 pounds (Lalman et al., 2000; Funston et al., 2012). Using fall 2024 Ontario feeder calf prices - roughly $5.45 per pound for smaller calves and $5.00 per pound for larger calves (Beef Farmers of Ontario, 2024) - the smaller-cow herd would wean a total of 15,000 pounds of calf (30 × 500 lbs), generating about $81,750 in gross revenue. The medium-large herd would wean 19,500 pounds (30 × 650 lbs), producing approximately $97,500 in gross revenue.
Feed costs in Ontario typically range between $460 and $515 per cow annually, depending on size and feeding practices (Beef Research Canada, 2023; Manitoba Agriculture, 2022). Smaller cows averaging 1,200 pounds incur feed costs closer to $460 per year, while medium to large-framed cows averaging 1,500 pounds require roughly $515 annually. This translates to total feed expenses of about $13,800 for the small-cow herd and $15,450 for the larger-cow herd.
After subtracting the feed costs from gross revenue, the smaller herd nets about $67,950, while the larger herd nets $82,050 - a difference of over $14,000 favouring the larger cows.
Now, consider reducing the medium-large herd by five cows, bringing it down to 25 animals, while the small-cow herd remains at 30. The 25 larger cows would wean 16,250 pounds of calf, generating about $81,250 in gross revenue (16,250 lbs × $5.00/lb). Their feed costs would total approximately $12,875 (25 × $515). After subtracting feed expenses, the net profit for this 25 head large-cow herd comes to roughly $68,375.
Despite having five fewer cows, the medium-large framed herd still out-earns the small-framed cow herd by over $400. The benefit of managing fewer animals also reduces labor and veterinary expenses, which in smaller Ontario herds often average $120 and $30 per cow annually, respectively (Beef Farmers of Ontario, 2023; Ontario Ministry of Agriculture, 2024; Canadian Beef Cattle Research Council, 2022). This means cutting five cows can save roughly $600 annually in labor costs, plus $150 in herd health-related expenses. Moreover, fewer cows reduce wear on equipment and infrastructure, lower bedding and handling costs, and simplifies overall management which offers additional benefits.
It’s also worth quickly mentioning replacements. While larger-framed replacement heifers may carry higher upfront costs (wether raised or bought in), they often deliver greater long-term value. Multiple studies show that larger cows tend to have superior longevity, higher breed-back rates, and fewer reproductive problems compared to their smaller counterparts (Funston et al., 2012; Canadian Journal of Animal Science, 2016). These larger cows typically remain productive in the herd longer and raise more pounds of calf over their lifespan. When they do exit the herd, their heavier mature weight also yields more revenue as cull cows - further improving their lifetime return.
So, while the initial assumption is that larger cows incur higher costs - primarily feed - their superior performance and longevity more than compensate for these expenses, ultimately delivering greater returns.
Physiological Foundations
While the financial side of cow size often gets the most attention, there’s a solid physiological reason larger-framed cows often outperform smaller ones in real-world grazing (and feedlot) systems. Much of it comes down to how ruminants use energy and process food - especially under variable conditions.
To start, larger cows are more efficient than many assume. According to Kleiber’s Law, metabolic rate increases at roughly 0.75 the power of body mass. That means a 1,600-pound cow doesn’t need 30% more energy than a 1,200-pound cow, even though she weighs 30% more (McNab, 2010). On a per-pound basis, she’s actually using energy more efficiently. It’s a bit like comparing vehicles - except in this case the heavy-duty truck gets better mileage per pound than the compact sedan. Bigger cows may eat more overall, but what they do with that energy is biologically more efficient.
Then there’s gut capacity. Larger ruminants can retain digesta longer, allowing more time to break down fibrous and lower-quality forage. This is explained by the Jarman–Bell Principle, which shows that larger-bodied animals are better equipped to extract energy from poor forage due to their greater rumen volume and longer fermentation time (Demment & Van Soest, 1985). That same capacity lets them fully capitalize on lush, high-quality pasture too - there’s no trade-off. The idea that big cows don’t suit marginal systems doesn’t hold up biologically.
This ties directly into how well they handle nutritional stress. During drought, cold snaps, or periods of poor pasture growth, smaller cows - especially if lactating - tend to lose condition faster. They have fewer reserves and less capacity to handle a drop in feed quality or intake. That condition loss can delay or prevent return to estrus, reduce conception, and stretch out calving intervals (Funston et al., 2012; O’Connor et al., 2018). If they’re already pregnant, energy deficits increase the risk of embryonic loss or abortion (Clinical Theriogenology, 2024; Missouri Extension, n.d.). And the effects don’t stop with the cow. Calves born to nutritionally stressed dams often come in lighter, grow slower, and have weaker immune function - impacts that follow them for the rest of their lives (Morris et al., 2014). In sheep, a study also shows that lambs born to underfed ewes have lower lifetime twinning rates and overall reduced fertility, likely due to developmental constraints in utero (Greenwood et al., 2000). These aren’t just theoretical concerns - they’re patterns producers see play out year after year.
In contrast, larger cows tend to be more resilient. Their size supports more internal reserves - fat, muscle, gut fill - that buffer them through tight periods. It’s not about having fat cows, but about having the metabolic insurance to maintain reproduction and calf growth through stressful periods. And once conditions improve, they bounce back faster than their smaller counterparts. This advantage isn’t unique to cattle. In an OMAFRA sheep study it was found that heavier ewes weighing over 50 kg at breeding had conception rates above 80%, compared to around 65% for those under 40 kg, particularly in low-input settings (OMAFRA, 2016). Similarly, in goats - especially those adapted to harsh environments - larger animals showed better heat stress tolerance and improved utilization of low-quality forage, which translated into higher fertility and kid growth rates (Devendra, 1992).
In addition, research on wild ruminants offers further insight into how body size influences resilience. A long-term genetic study of Soay sheep - an isolated population that has been wild for thousands of years on in the Scottish Archipelago - found that larger individuals consistently carried lower burdens of intestinal parasites, as measured by fecal egg counts (Hayward et al., 2011; Wilson et al., 2004; Nussey et al., 2007). This indicates a positive genetic correlation between body size and parasite resistance - larger sheep weren’t just bigger, they were hardier. Importantly, the study found no evidence of a trade-off between growth and immunity. Instead, these traits were genetically aligned: animals predisposed to be larger were also more likely to resist parasitic infections. These findings suggest that even in wild systems, larger ruminants are better equipped to maintain health under natural parasite pressure - another biological advantage that complements their superior digestive capacity and reproductive resilience.
Temperature tolerance plays a role too - especially in areas like ours, where it’s not uncommon to swing from -35°C in winter to 40°C in summer. From an evolutionary and ecogeographic standpoint, larger body size is also associated with increased cold-stress tolerance. This principle, known as Bergmann’s Rule, describes how animals in colder climates tend to evolve larger body masses, which help conserve heat through a lower surface-area-to-volume ratio. This trend is observable not only in cattle but also across wild and domestic ruminants, from reindeer and bison to northern-adapted sheep and goat breeds. Fossil and paleo records also reveal that as the climate cooled during the Ice Age, many large herbivores followed this evolutionary trajectory, increasing in body size over time to better cope with the harsher conditions and poorer vegetation quality (Geiger et al., 2017; McNab, 2010). Larger animals generally retain body heat more efficiently, making them better suited to withstand prolonged cold, wind, and wet conditions without compromising body condition or reproductive performance (Geiger et al., 2017; McNab, 2010).
At the same time, larger cows are not at a disadvantage in hot climates despite this common belief. As long as they have access to shade and water (which is just as relevant to smaller animals), their greater internal reserves help them withstand heat-induced drops in feed intake or pasture quality. When high temperatures suppress appetite and growth, smaller animals may decline quickly, while larger ones continue producing and maintaining condition thanks to a larger body reserve and more efficient forage use (Devendra, 1992; Mota-Rojas et al., 2020). A comparative study of standard-size vs. dwarf cattle breeds in Kerala, India further supports this. The average temperatures there are 30°C to 35°C (45°C to 50°C with humidex), quite a hot and humid climate. The findings of the study showed that the larger cattle actually maintained lower heat stress signs and demonstrated more stable thermoregulation under thermal pressure that their dwarf counterparts (Thomas et al., 2019).
In short, larger cows are physiologically better equipped to deal with the realities of grazing-based production: uneven forage quality, seasonal weather swings, parasites and the nutritional demands of lactation. These aren’t just theoretical traits - they show up in herd performance, year after year.
The Trouble with Weaning Efficiency
Weaning efficiency (WE) - typically defined as calf weaning weight divided by dam weight - is often touted as a convenient benchmark for maternal productivity. On paper, it seems to level the playing field by measuring how much saleable weight a cow produces relative to her size. But in practice, the metric is riddled with inconsistencies that make it difficult to interpret across seasons, let alone different herds under different management practices.
The first major inconsistency lies in how and when cow weight is recorded. Industry convention often uses weight at weaning, after the cow has raised a calf through months of lactation - frequently her lowest body condition point of the year (Funston et al., 2012; O’Connor et al., 2018). Cows under forage or heat stress may lose significant weight by weaning, which inflates the apparent weaning efficiency. In contrast, weighing cows shortly after calving - once fetal and placental weight has been shed, but before lactation takes its toll - offers a more stable and biologically representative measure of the cow’s true mass (Devendra, 1992; McNab, 2010). This method reduces the bias introduced by environmental stressors and management variability that disproportionately affect lighter cows with fewer body reserves.
This matters because smaller-framed cows are more likely to experience rapid body condition loss during periods of nutritional stress. A weaning efficiency metric that rewards cows for being lighter - even if that weight loss reflects declining health and fertility - can mask long-term inefficiencies. Larger cows, with more body reserves and greater digestive capacity, are often better able to maintain weight, rebreed on time, and support steady calf development through those same periods (Demment & Van Soest, 1985).
Another problem with WE arises from how calf weights are adjusted. The 205-day adjusted weaning weight is a standard tool - but only meaningful when applied uniformly. If some calves are creep-fed while others aren’t, or if pasture quality varies dramatically, calf weights can reflect management inputs more than maternal merit (Morris et al., 2014). Smaller cows are sometimes favored under this system simply because their calves are easier to supplement or creep feed, producing a misleading efficiency advantage.
Environmental conditions further complicate matters. In drought years, cows - especially small ones - may wean smaller calves but lose more weight themselves, paradoxically resulting in higher WE percentages. In good years, both cow and calf weights rise, but the ratio may stay flat or decline, obscuring actual gains in output. Without context, a high WE figure might mean either a highly efficient cow or a nutritionally stressed one raising a small calf on minimal reserves.
Finally, the reliability of weaning efficiency depends entirely on accuracy - and many producers don’t use scales regularly, or at all. Visual estimates or old average weights are common, and these shortcuts are especially problematic when comparing across frame sizes. A cow who’s size is over or underestimated skewers the entire metric and may unfairly penalize an animal whose true contributions are greater.
In theory, the weaning efficiency metric is intended to balance calf productivity against dam maintenance cost. In practice, though - especially when applied inconsistently or without context - can produce misleading comparisons. Cows that lose weight during lactation may appear more efficient simply because they’re lighter at weaning, while cows that maintain good body condition are penalized by a heavier denominator. Larger cows, in particular, may be unfairly judged, even when their added mass reflects superior maternal capacity and long-term resilience - not excessive input cost. When these cows rebreed reliably and wean heavier, healthier calves year after year, their true efficiency becomes apparent - just not always in the weaning efficiency formula.
“Eggs in One Basket”? The Risk Argument
Another common argument in favor of smaller cows is the idea of “not putting all your eggs in one basket.” If a rancher can run more small cows for the same total feed as fewer big cows, then losing one has less impact - or so the thinking goes. While this sounds risk-savvy and forward thinking in theory, it doesn’t always play out that way in practice.
Smaller cows generally produce smaller calves and may have lower pregnancy and weaning rates. This means that even with more cows - total pounds of weaned calf per acre (or per ton of forage) may not increase - and it may even decline. If a larger cow produces heavier, healthier calves with more consistency and stays in the herd longer, the loss of one such animal could still represent a net economic gain over several smaller cows with poorer lifetime performance.
Furthermore, running more animals means higher handling and labor demands, increased infrastructure wear, more exposure to injury, and potential compounding of disease pressure. In challenging forage years or health events, more animals may not be an asset - they can be a liability. Risk mitigation isn’t only about herd size - it’s also about structural soundness, health history, and productivity per unit. A fewer number of well-built, reproductively efficient cows may offer greater consistency and long term resilience than a larger group of less-productive animals.
Safety Considerations
Another argument occasionally raised against larger cows is the perception that they are harder or more dangerous to manage. However, animal behavior and handling risks are more closely tied to temperament, personnel training, and facility design. Studies in small ruminants show that flighty or aggressive temperaments pose greater risk to handlers than animal size (Kilgour & Dalton, 1984). In fact, smaller-framed cattle can give a false sense of safety, leading handlers to take less precautions or take riskier actions - despite the reality that a 1,000-lb cow can cause just as much injury as a 2,000-lb cow if mishandled.
Moreover, larger cows may actually be less prone to injury during breeding, particularly in natural service systems. Although direct research comparing injury rates in cattle is limited, studies in wild ruminants such as elk and red deer support this concept: larger females tend to have higher breeding success and sustain fewer injuries during mating, whereas smaller females bred by significantly larger males are more susceptible to pelvic injuries (Clutton-Brock et al., 1982; Guinness et al., 1978). It stands to reason that cows with adequate frame and structural soundness are less likely to experience pelvic strain, hip displacement, or soft tissue trauma when bred by a mature bull. Conversely, small-framed cows bred to large bulls - which commonly occurs in crossbreeding programs pairing smaller maternal breeds with larger terminal sires - may endure increased physical stress, especially during early estrus when mounting activity is more frequent and vigorous.
Good stockmanship, temperament selection, and proper facilities ultimately have a far greater impact on safety and animal welfare than frame score alone.
Why Dairy Trends Don’t Apply
Much of the recent push toward smaller cows in the beef industry has drawn parallels from dairy, where some operations have begun selecting for slightly lighter-framed cows over the larger-framed ones of previous decades. But it’s important to recognize that dairy and beef operate under fundamentally different systems - with very different measures of performance and efficiency.
Dairy cows are bred and managed to produce milk, not raise calves or maintain condition on variable pasture. Their environments are tightly controlled: stable indoor climates, formulated total mixed rations (TMR), and minimal energy spent on thermoregulation, foraging, or long-distance movement. Crucially, dairy producers are paid based on milk volume (litres), not live weight or carcass weight, so frame size itself has less direct economic impact beyond its influence on production. This means that any conclusions about optimal cow size within dairy systems, especially those operating under barn-based management, don’t necessarily translate to real-world, forage-based beef production, where income is closely tied to pounds of meat produced.
However, when dairy cows are managed under more extensive, pasture-based conditions, the data tells a different story. A large-scale New Zealand study evaluating over 140,000 grazing dairy heifers found that higher pre-calving body weights were strongly associated with increased milk production during first lactation. Specifically, each additional kilogram of body weight at calving was associated with 4.8 to 6 more litres of milk per day in first lactation (Roche et al., 2007). These effects carried through into subsequent lactations as well.
In other words, larger-framed cows performed better under grazing conditions - not because they were being pampered with high-energy feed, but because their greater body capacity and intake potential allowed them to better convert pasture into production. This finding undercuts the assumption that smaller is inherently more efficient, even within the dairy world. When conditions resemble beef production - grazing, variable forage, exposure to the elements - larger animals consistently prove more resilient and productive.
In the End
What’s often overlooked in the discussion around cow size and efficiency is the value of measured performance data and functional soundness. Larger-framed cows, when matched to the environment and managed appropriately, can produce heavier calves with fewer reproductive setbacks, better resilience in challenging conditions, and overall improved lifetime productivity.
Importantly, producers need to know what they’re working with to make educated management decisions - not just rely on visual estimates or breed stereotypes. If producers don’t actually weigh their cattle, assumptions about “small” and “large” are based on guesswork which has no value. What one rancher calls a “moderate cow” might actually be 1,500 pounds or more, placing her well into the mid or upper range in these studies. Without scales or proper frame scoring, it’s easy to misinterpret research findings - and overlook high-performing cows that quietly outproduce their smaller herd mates.
Efficiency should be assessed as a holistic measure - accounting for intake, reproductive success, calf output, longevity, adaptability, and management practicality - not simply minimized cow size and feed intake.
It’s also worth acknowledging that some of the messaging around smaller cows has more to do with breed marketing than cow-calf efficiency. Certain breed associations - especially those tied to popular black-hided programs - have a clear incentive to promote cattle that match a specific visual profile. That often means pushing smaller-framed animals, not necessarily because they perform better, but because they fit a standardized box that helps sell seedstock and supports branded programs. Over time, this marketing has reshaped how “efficiency” is defined - favouring lighter cows even when larger-framed genetics consistently deliver more pounds of calf, better feedlot performance, and greater value for producers. At the end of the day, no marketing message can replace your own records and experience - producers know best what works on their land and in their herds.
Our experience, supported by multiple peer-reviewed studies across cattle, sheep, goat, and wild ruminant production, confirms that bigger cows aren’t inherently less economical; in many cases, they are more productive, more resilient, and more profitable in the long run. You just have to take the time to read and the literature and analyze the proper numbers.
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