Lactation Curve in Cattle: Definition and Importance

The lactation curve is the graphic profile of a cow's milk production throughout its productive cycle (from the end of the colostrum phase until drying off). It typically spans about 305 days of milking and approximately 60 days of dry period before the next calving.

ANIMAL PRODUCTION

7/30/202511 min read

The lactation curve is the graphic profile of a cow's milk production throughout its productive cycle (from the end of the colostrum phase until drying off). It typically spans about 305 days of milking and approximately 60 days of dry period before the next calving (1, 2). In practice, the goal is one calving per year: cows are milked for about 305 days and then dried off for 50–60 days before the next calving (2, 3). This indicator is fundamental because it allows for the evaluation of the productive performance of each cow and the herd, and enables management and genetic selection decisions. Understanding the shape of the curve helps maximize production at key moments and improve profitability (4, 5). For example, optimizing the curve allows for more consistent milk revenues throughout the year, which is especially valuable in intensive dairy systems (5, 6).

Phases of the Lactation Curve

The lactation curve is characterized by several stages:

Onset of lactation: After calving, colostrum is removed, and commercial milking begins. Daily production rapidly increases in the first few weeks as feed intake rises and the mammary gland becomes active (4, 7).
Ascent to peak: The rate of production increase (upward slope) defines how quickly the maximum point is reached. This lactation peak usually occurs between 4 to 10 weeks postpartum (approx. 1-2 months) in specialized dairy breeds (5, 8). In well-fed Holstein cows, the peak can be around 30–40 L/day, while in Jersey it is lower (in the cited study, 36 L/d vs 25 L/d) (8).
Peak production: This is the maximum daily level. From there, the curve begins to decline. Young cows (heifers) usually reach their peak slightly earlier and at a lower volume than mature cows, but they maintain the level with more persistence (8, 9).
Decline and persistence: After the peak, daily production gradually drops. Lactation persistence refers to how flat or steep this decline is. A persistent curve is flatter (the decline is slow) and is often associated with cows that maintain production better after the peak (10, 11). In practice, young cows often have greater persistence: studies show that primiparous cows lose production more slowly than adult cows, indicating greater persistence in heifers (9, 10).
Final phase and dry-off: Near the end of lactation, production drops sharply. Finally, the cow is dried off, ceasing production for a period before the next calving.

Factors Affecting the Curve Shape

The shape of the lactation curve is influenced by multiple genetic and environmental factors. In general, any factor affecting the cow before or after calving will modify the curve, either "flattening" (greater persistence) or "shortening" (shorter duration or lower peak) milk production (5, 12). The most relevant factors include:

Breed and genetics: Specialized dairy breeds (Holstein, Jersey, Brown Swiss, Normande, etc.) are genetically selected for high production and steep curves (high peaks). In contrast, adapted Zebu breeds (Gir, Brahman, Sahiwal, etc.) or dual-purpose crosses often have lower peaks but sometimes better persistence and heat adaptation (13, 14). Within a breed, genetic persistence can be increased by using bulls with a high persistence breeding value (EBV). For example, bulls with a persistence EBV >100 produce daughters with flatter curves (less milk early and more later) (15).
Parity (lactation number): Cows in their first lactation have not yet completed their growth, which is why they produce less initially. Studies have shown that the second lactation can increase total production by ~28% compared to the first (16). With each additional lactation, the peak is usually higher, but the decline slope is steeper, reducing relative persistence (10, 16). In fact, under grazing conditions, primiparous cows showed lower production than multiparous cows until week 20, then caught up, suggesting greater persistence in heifers (9).
Nutrition and feeding management: Diet is crucial for achieving a good peak and maintaining production. A poorly fed cow (insufficient energy or protein levels) will have a lower peak and a faster drop. Similarly, poor body condition before or during lactation (both low and excessively high) will affect the curve (5). It is crucial to balance the ration for cows with the highest potential, avoiding energy deficits in early lactation. Maintaining good body reserves and a positive energy balance reduces risks (less curve shortening) (5, 11).
Health status: Metabolic diseases (ketosis, hypocalcemia), mastitis, or other health problems impair dairy performance. For example, postpartum hypocalcemia can reduce early production; mastitis increases the curve's decline. A healthy herd tends to maintain better production.
Reproductive management: Reproductive status indirectly influences the curve. Cows that conceive early tend to dry off sooner (shorter lactation), while a difficult calving can hinder the curve. Ideally, insemination aims for conception around 60–80 days into lactation, so the cow can be dried off at 305 days and calve every ~12 months (2, 3). Excessive open days prolong lactations (low efficiency per additional day without offspring) or require very long dry periods.
Climate and seasons: In seasonal grazing systems (e.g., in temperate or tropical regions), the peak may align with seasons of better forage. Argentine studies show that cows calving in spring achieve higher and more sustained peaks than those calving in autumn; the calving season can modify the decline pattern (9, 16). Likewise, heat stress (intense heat) reduces intake and usually lowers the lactation peak and shortens the curve.
Milking frequency and photoperiod: More frequent milking (e.g., 3 times/day) increases the peak and favors persistence. Exposing cows to long days (16-18 hours of light) increases production and flattens the curve (17).

In summary, the curve reflects the interaction of genetics and management. Greater genetic potential and better management (nutrition, health, environment) generally lead to higher production and better persistence curves (5, 18).

Differences: Dairy, Dual-Purpose, and Beef Cattle

Dairy-specialized cows (dairy Bos taurus) exhibit lactation curves far superior to others. For example, Holstein cows under high nutrition conditions can produce tens of thousands of liters in a lactation (e.g., 10,000–12,000 L with ease, even exceptional cases >20,000 L) (19, 20). Jersey cows produce less volume (6,000–10,000 L per lactation) but with high fat content (13). Other European breeds (Brown Swiss, Normande) can also exceed 6,000 L; for instance, 6,000–7,000 L/lactation is reported for Normande and 10,000–12,000 L for Brown Swiss (20). These curves have very high peaks (30–40 L/d) and rapid declines, aiming for maximum daily yields.

In dual-purpose cattle farming (Bos taurus × Bos indicus, or rustic crossbreeds), yields are intermediate. For example, Girolando cattle (5/8 Holstein + 3/8 Gyr mix) adjusted to 305 d/lactation produce an average of about 3,500 kg (22). Gyr cows in the tropics produce an average of 9–12 L/day (2,500–4,000 kg per lactation) (14), although in India, exceptional cases can reach up to 50 L/d (23). In practice, tropical crosses (Holstein × Brahman, Holstein × Gir, etc.) usually yield several thousand kg, offering greater climatic hardiness.

In beef cattle, lactation primarily aims to ensure calf growth. British beef breeds traditionally wean calves at good weights: studies in Argentina report ~900 kg of milk in 230–240 days of lactation for Shorthorn or Aberdeen Angus, compared to ~592 kg for Hereford (24). This equates to average daily milkings of 3–5 kg/d. Zebu breeds (Brahman, Nelore) are less milky: for example, pure Brahman yielded about 2 kg/d (≈600 kg/lact) and Santa Gertrudis (5/8 Shorthorn + 3/8 Brahman) about 6.8 kg/d (25). In extensive beef farming systems, the curves are lower, with low peaks and sharp declines, as production is limited by pastures and maximum milk output is not sought. In these systems, nutritional management (forage level) largely determines the curve's shape (24, 26).

Examples of Curves by Breed

As concrete examples, typical curves or adjusted models in different breeds can be cited:

Holstein-Friesian: The world's leading breed. Characterized by a very high peak (~35–40 L/d) at 40–60 days postpartum and a sharp decline in subsequent months. With good feeding, it can have lactations >10,000 kg. For instance, in Spain, an average of around 12,000 L (305 d) with 3.7% fat is reported (19).
Jersey: Smaller in size, its peak is lower (~25–30 L/d), but it maintains a higher fat percentage (4–5%). They reach lactations of 6,000–10,000 kg. They adapt better to forage-rich diets; studies indicate 5,000–6,000 L in extensive tropical systems (13).
Normande: A dual-purpose breed with a dairy bias. Moderate peaks (~20–25 L/d) and good composition. They produce ~6,000–7,000 L/lactation (21).
Brown Swiss: High production almost at Holstein levels. Peaks of ~35 L/d, with lactations of 10,000–12,000 L (20).
Gir (Bos indicus): A dairy Zebu breed originating from India. Under moderate conditions, it yields ~9–12 L/d (approx. 3,000 L/lact) (14). However, in its native India, exceptional animals reaching 50 L/d have been reported (23).
Brahman and Santa Gertrudis: Pure Brahman is not very milky (~2 kg/d according to some references) (25), while Santa Gertrudis (a Zebu-British mix) can yield ~6–7 kg/d. In Brazilian pastures, Gyr-Holstein crosses (Girolando) achieve ~3,500 kg/lact (22).
Latin American Criollas: Criolla or Criollo Limonero breeds typically produce ~2,000–3,000 kg/lact (FAO data suggests ~2,500 kg) with lactations of ~240–300 days. Their curves are flat due to adaptation to extensive grazing.

In comparative studies, for example, Holstein and Jersey cows under similar conditions showed similarly shaped curves, but Holsteins had 33% higher production in the initial phase (7). Jerseys reached their peak earlier (3 weeks vs 5 weeks) but at a lower volume (8). This type of study is used to adjust mathematical models (Wood, Wilmink, etc.) that describe the curve and allow for the estimation of parameters (initial level, ascent/descent rate, etc.) (5, 27).

Associated Productive Parameters

When analyzing a lactation curve, several key parameters are usually defined:

Lactation length: Months the cow is in production. In intensive systems, it is normalized to ~305 days (2); in extensive livestock farming, it may be shorter.
Total production: Accumulated liters at the end of the normalized lactation (e.g., 305 days). Reflects overall efficiency.
Peak production: Maximum daily liters achieved, an index of performance at the critical stage.
Persistence: Rate of decrease after the peak. It is quantified in various ways (production ratio at 280 d vs 60 d, descent slope, etc.) (10). Flatter curves (high persistence) imply relatively more late production. It is favorably associated with cow health and longevity (11, 18).
Calving interval (CI): The period between one calving and the next. Ideally, ~365–380 days (1 year) is sought. This means drying off the cow around 305 days of lactation to achieve an annual cycle (2, 3). A long CI (low conception or long rests) extends the curve or results in more dry cows, reducing annual efficiency.
Days open (DO) and reproductive indices: Although not directly part of the lactation curve, they are linked because reproductive status determines lactation length and body condition, affecting the curve's shape.

Higher total production and peak usually lead to reduced relative persistence. For example, in Holstein cows, it was observed that third lactations with higher peaks had steeper declines (10). Therefore, in dairy herd evaluation, indices like "days to peak" or "degree of persistence" are calculated to make decisions.

Practical Strategies to Improve the Lactation Curve

To optimize the lactation curve in the operation, several management practices are recommended:

Adequate nutrition at each stage: Balance the diet according to the phase. In the initial phase, sufficient energy and protein must be ensured (e.g., balanced concentrates with high-quality forages) to promote the peak. It is useful to define the ration based on the performance of the most productive cows (28). Maintaining the same feed quality for the entire herd and reviewing production records helps detect anomalous drops. It is also advisable to maintain body condition (~BCS 3–3.5) during lactation, supplementing silages or grains if necessary (5, 28).
Effective reproductive management: Early insemination (around 60–80 days postpartum) is key to getting the cow pregnant during production and being able to dry her off on time (60 days before calving) for a CI of ~365 days (2, 3). The reproductive program must be coordinated so that lactation is not unnecessarily prolonged, nor cows dried off excessively.
Genetic selection for persistence: Incorporating bulls with high persistence (good EBV) produces daughters with flatter curves. This improves production stability and, in the long term, herd health (11, 15).
Health control and stress management: Prevent metabolic diseases (e.g., balancing pre-calving calcium) and mastitis; also, mitigate heat stress through shade, ventilation, or cooling in warm seasons. A stress-free cow can express her genetics better.
Milking frequency and photoperiod: Milking more frequently (e.g., 3 times/day at peak) increases the peak and can improve persistence. Extending day length (light >16 h/day) also promotes production and prolongs the lactation curve (flatter curve).
Continuous monitoring: Keeping weekly production records allows for management adjustments. Unusual drops in the curve should be quickly detected, and the cause corrected (feeding, health, failed insemination, etc.) (5, 28).

In general, the goal is to obtain a balanced lactation curve: a high peak but without the cow excessively losing body reserves, while maintaining reasonable persistence. Flat curves are desirable because they reduce the negative energy balance postpartum and translate into healthier and longer-lived cows (11, 18).

Regional Examples

Latin America: In tropical systems, Criolla breeds or crosses with Holstein typically predominate. For example, in Costa Rica, a Jersey cow was observed to produce about 1.8 L/day less on average than a similar Holstein (day 2 to day 305) (29). In Argentina, field studies in grazing herds found that cows calving in spring achieved higher and sustained peaks than those calving in autumn (9, 16). In South American beef cattle, British breeds allow for weaning heavy calves (~900 kg milk/lact) (30).
Europe: With intensive systems, European Holstein cows typically average between 7,000 and 10,000 kg/lact (e.g., Holstein in Spain ~12,000 L) (19, 20). The EU as a whole reported an average apparent yield of ~7,800 kg/cow in 2023 (31), with Nordic and Baltic countries above and Eastern Europe below that average. Additionally, native breeds such as Brown Swiss or Jersey also contribute to high dairy production in the EU (13, 20).
India and Asia: India is the world's largest milk producer, based on Zebu cows (Gir, Sahiwal) and buffaloes. In their native region, some Gir cows can yield up to 50 L/d at peak (23). However, most small producers achieve modest yields (~1,360 L/year per cow) (32) due to extensive systems. In general, native Asian breeds have very flat curves but low peaks (e.g., 20–30 L at peak).
United States: Primarily Holsteins are used in intensive confinement. The average yield per cow (including pasture) was 23,391 lb in 2019 (≈10,600 kg) (33). There, the typical 305-day curve follows the classic pattern: peak around 60–70 d with ~35–40 L/d, gradually declining. It is worth noting that in the U.S., modern selection strategies have significantly increased lactation yield (+10.6% from 2010–2019) (33).

Each region adapts the curve to the available production system: climate, breeds raised, and feeding levels mean that there is no single global "standard curve," but rather variations depending on the environment (5, 32).

References

The information above is based on updated scientific and technical literature, dairy farming reports, and regional case studies (2, 4, 5, 13, 22, 24, 31, 33), among others. Each cited data point can be consulted in the linked sources.

(1) Cómo analizar una curva de lactancia en vacas lecheras | Fedegán

https://www.fedegan.org.co/como-analizar-una-curva-de-lactancia-en-vacas-lecheras

(2, 4, 5, 9, 12, 16) IDIA_9_1_armado final.qxp

https://www.produccion-animal.com.ar/produccion_bovina_de_leche/produccion_bovina_leche/139-curva_produccion.pdf

(3) CURVA DE LACTANCIA | Engormix

https://www.engormix.com/lecheria/miscellaneous/curva-lactancia_f6848/

(6, 11, 15, 18, 34) La persistencia de la lactancia: una herramienta

https://www.vikinggenetics.com/es/noticias/la-persistencia-de-la-lactancia

(7, 8, 27) C:\RevistaWeb\Sistemas.wpd

https://www.produccion-animal.com.ar/produccion_bovina_de_leche/razas_lecheras/106-curvas_lactancia.pdf

(10, 17) Evaluating Milk Peak and Persistency Using DHIA Data Part 1

https://extension.psu.edu/evaluating-milk-peak-and-persistency-using-dhia-data-part-1