1. Introduction
Numerous factors affect U.S. cow-calf profitability. Some factors are outside of the control of producers, such as prevailing market prices and weather. But others, such as breed and frame size, are controllable determinants of profitability. Of interest in this study are how differences in birth weights, calving interval, weaning weights, and feed expenses vary across Angus-, Red Angus-, and American Aberdeen-influenced cow herds and how those differences translate into profits. The three breeds derive from the same lineage but have developed under different selection pressures. In 1873, four Angus bulls were transported from Scotland to Kansas (American Angus Association, 2020). Over the next decade, 1,200 Angus cattle were imported to the Midwest, eventually becoming the American Angus breed (American Angus Association, 2020). Red Angus cattle was derived from Angus cattle but with red pigmentation due to a recessive gene (Oklahoma State University, 2015).
The origins of the Aberdeen breed date to 1974. An Angus herd at the Trangie (Australia) Research Center was separated into a “Lowline” herd, who had low yearling growth rates, and a “Highline” herd, who had high yearling growth rates (Barnett, Reference Barnett2020). After 15 years of researching the two herds, the “Lowline” herd stabilized at 30% smaller than the “Highline” herd (Barnett, Reference Barnett2020). “Lowline” cattle were imported into the U.S., becoming the American Aberdeen breed. Aberdeen cows are known for their calving ease, docility, low feed requirements, and higher stocking rates (Barnett, Reference Barnett2020).
While these three breeds have a common origin, selection pressures have changed genetics and phenotypes, including mature weight. This is relevant as mature beef cow weight has steadily increased in U.S. herds (Wiseman, Lalman, and DeVuyst, Reference Wiseman, Lalman and DeVuyst2018), leading to increased weaning weights. However, Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018) found the marginal gains from heavier weaned calves from larger cows are offset by increased feed costs due largely to lower stocking rates, so larger cows had lower economic returns. Since the Aberdeen breed was selected for lighter cow weights, the results from Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018) suggest potential for higher cow-calf profits than their Angus and Red Angus cousins.
Calving interval, that is, the number of days between subsequent calving, also affects cow-calf profitability. A narrow calving window (<60–90 days) translates into more uniform calves and larger lot sizes at auction, potentially increasing returns. Ward, Ratcliff, and Lalman (Reference Ward, Ratcliff and Lalman2017) found that calves marketed in uniform lots of 10 head or more receive higher premiums than smaller non-uniform lots. Williams et al. (Reference Williams, Raper, DeVuyst, Peel and McKinney2012) found a lot selling one calf had prices $7.00/cwt less than a lot selling ten calves for identical weight and quality.
Ideally, a cow will produce one calf at the same time each year after being successfully bred during a breeding window. If a cow does not successfully rebreed in the allotted time, the producer must decide whether to transition her to a later breeding season, cull her, or retain her with delayed calving (Carpenter and Sprott, Reference Carpenter and Sprott2020). Cow-calf operations with tight calving intervals were more profitable (Amundson, Reference Amundson2020). Tight calving intervals lead to more uniform calves that better meet demand (Howard, Reference Howard2013). Brown et al. (Reference Brown, Durham, Cobb and Knox1954) concluded that calving intervals are influenced by calf’s sire, nutrition, age, and the birth weight of the cow’s previous calf. Titterington et al. (Reference Titterington, Lively, Dawson, Gordon and Morrison2017) reported dam breed and age and calving month significantly affect calving interval. According to Frazier et al. (Reference Frazier, Sprott, Sanders, Dahm, Crouch and Turner1999), higher birth weight resulted in longer mature cow calving interval. Birth weight and weaning weight predicted calving interval but were affected by changes in growth traits (Frazier et al., Reference Frazier, Sprott, Sanders, Dahm, Crouch and Turner1999). Doren, Long, and Cartwright (Reference Doren, Long and Cartwright1986) found “weaning weight of the previous calf was positively correlated with postpartum conception and calving interval.”
Given previous research, it is possible, even likely, that genetic and phenotypic differences between Angus, Red Angus, and Aberdeen breeds differentially influence calving interval. Beef cows with recorded influence, that is percentage breed cows, from these three beef breeds are evaluated here. We hypothesize these cows differ in calving interval, weaning weights, revenues, and associated production costs. To determine the economic impact of genotypic and phenotypic differences between these breeds, we estimate models of birth weight, calving interval, and weaning weight. Feed costs, a critical component in economic returns, are approximated using a ration software tool. We then use these models to estimate expected biologic and economic returns by breed.
2. Bio-economic Model
It is assumed that the producer’s objective is to maximize weighted average expected returns to fixed costs, labor, and management from cow-calf production by choosing sire and dam breeds. Mathematically,
$${\mathop {Max}\limits_{D,S} \sum\limits_{m = 1}^{10} {[E[(Weaning \, Weight(D,S,Age \, at \, weaning(CI,D,S)] \times E[Price(Weaning \, Weigh{t_m})} ] \\ \quad + E(CullCowRevenue(D)) - E[Cost(Cow \, weigh{t_m},ag{e_m},D)]) \times p(m) \times CC\% ]/Acres \, per \, head(Cow\;weigh{t_m})} $$
where D and S are dam and sire breeds, respectively, t is the age of the cow, CI is calving interval, p(m) is the proportion of the cow herd of age m, and CC% is the percent calf crop. The model is normalized on acres required per head assuming pasture acres are fixed for a producer. Even though per head profits might be highest for a breed, higher forage requirements, and thus lower stocking rates, means fewer heavy-weight cows can be stocked on a given acreage. Total profits can then be higher for lighter-weight cows with lower per head profit but a higher stocking rate.
To calculate weighted average profits, weaning weights were estimated for Angus- (AN), Red Angus- (AR), and Aberdeen-(LOFootnote 1 ) influenced beef cows and bulls. Weaning weights were estimated functions of birth weights and calf age at weaning (among other variables), similar to Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018). Given the potential for calving interval to differ between sire and dam breeds, calving interval was also estimated and used to calculate calf weaning age on October 31, the assumed weaning date. Empirical model specifications for birth weight, calving interval, and weaning weights are discussed below.
2.1. Empirical Models
2.1.1. Calf Birth Weight Model
A model, modified from Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018), was used to estimate birth weight as a function of dam and sire breeds, dam’s weight, age, and age squared, year of birth, and calf sexFootnote 2 and specified as:
$${ CalfBirthWeigh{t_{ist}} = {\alpha _1} + {\alpha _2}AD{G_{i,t - 1}} + {\alpha _3}CowBCSatWea{n_{i,t - 1}} + {\alpha _4}CowWeightAtWea{n_{i,t - 1}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \,\,\, + {\alpha _5}CowAg{e_{it}} + {\alpha _6}CowAge_{it}^2 + {\alpha _7}A{R_{it}} + {\alpha _8}L{O_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \,\,\, + {\alpha _9}C\_A{R_{it}} + {\alpha _{10}}C\_L{O_{it}} + {\alpha _{11}}C\_Unkwn \\ \quad \quad \quad \quad \quad \quad \quad \quad \,\,\, + {\alpha _{12}}C\_U{K_{it}} + {\alpha _{13}}C\_Con{t_{it}} + {\alpha _{14}}CalfBirthYea{r_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \,\,\, + {\alpha _{15}}CalfSe{x_{it}} + {e_{it}} + {v_t} + {d_i} + {\rho _s}} $$
where
$CalfBirthWeigh{t_{ist}}$
denotes calf birth weight for dam i, sire s, and year t, α
1 denotes the intercept (base of Angus sire and Angus dam).
$AD{G_{i,t - 1}}$
denotes the average daily gain from the dam’s previous calf during nursing.
$CowBCSatWea{n_{i,t - 1}}$
denotes the dam’s body condition score at her previous weaning.
$CowWeightAtWea{n_{i,t - 1}}$
denotes the dam’s weight at her previous weaning.
$CowAg{e_{it}}$
denotes the age of the dam and was estimated in quadratic form.
$A{R_{it}}$
denotes a Red Angus sire and
$L{O_{it}}$
is an Aberdeen sire.
$C\_A{R_{it}}$
denotes a Red Angus dam,
$C\_L{O_{it}}$
is an Aberdeen dam,
$C\_UNKW{N_{it}}$
are the dams of unknown breeds,
$C\_U{K_{it}}$
are dam breeds from the UK (other than AN, AR, and LO), and
$C\_CON{T_{it}}$
are Continental dam breeds.
$CalfBdateYea{r_{it}}$
is the year that the calf was born.
$CalfSe{x_{it}}$
indicates calf sex ϵ{Heifer, Bull}. The error term, e
it
, and random effects for year v
t
, individual dams d
i
, and individual sire ρ
s
are assumed to be independent and normally distributed for dam i, sire s, and year t.
2.1.2. Calving Interval Model
Calving interval was specified as:
$${LnCalvingInterva{l_{ist}} = {\beta _1} + {\beta _2}BirthWeightRati{o_{i,t - 1}} + {\beta _3}AD{G_{i,t - 1}} + {\beta _4}CowBCSatWea{n_{i,t - 1}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \, + {\beta _5}CowWeightAtWea{n_{i,t - 1}} + {\beta _6}CowAg{e_{it}} + {\beta _7}CowAge_{it}^2 + {\beta _8}A{R_{it}} + {\beta _9}L{O_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \, + {\beta _{10}}C\_A{R_{it}} + {\beta _{11}}C\_L{O_{it}} + {\beta _{12}}C\_Unkwn + {\beta _{13}}C\_U{K_{it}} + {\beta _{14}}C\_Con{t_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \, + {\beta _{15}}CalfBirthYea{r_{it}} + {\beta _{16}}CalfSe{x_{it}} + {\varphi _{ist}} + {r_t} + {\tau _i} + {\chi _s}} $$
where
$LnCalvingInterva{l_{ist}}\;$
denotes the natural logarithm of the number of days between each calving for dam i and year t. β
1 denotes the intercept for an Angus sire and Angus dam.
$BirthWeightRati{o_{i,t - 1}}$
is lagged birth weightFootnote
3
divided by dam weight at weaning from the previous year. The error term ϕ
it
and random effects for dam τ
i
, sire χ
s
, and year r
t
are assumed to be independent and normally distributed.
2.1.3. Weaning Weight and Dam Weight Models
A model also modified from Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018) was used to estimate weaning weight as follows:
$${ CalfWeaningWeigh{t_{ist}} = {\delta _1} + {\delta _2}A{R_{it}} + {\delta _3}L{O_{it}} + {\delta _4}CalfBirthWeigh{t_{it}} + {\delta _5}AgeAtWea{n_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad + {\delta _6}CowBCSatWea{n_{i,t - 1}} + {\delta _7}CowWeightAtWea{n_{i,t - 1}} + {\delta _8}CowAg{e_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad + {\delta _9}CowAge_{it}^2 + {\delta _{10}}C\_A{R_{it}} + {\delta _{11}}C\_L{O_{it}} + {\delta _{12}}C\_Unkw{n_{it}} + {\delta _{13}}C\_U{K_{it}} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad + {\delta _{14}}C\_Con{t_{it}} + {\delta _{15}}CalfBirthYea{r_{it}} + {\delta _{16}}CalfSe{x_{it}} + {u_{it}} + {w_t} + {\phi _i} + {\eta _s}} $$
where
$CalfWeaningWeigh{t_{ist}}$
denotes calf weaning weight for a calf from dam i, sire s, and year t, δ
1 denotes the intercept for an Angus sire and Angus dam. The error term u
it
and random effects for dam ϕ
i
, sire η
s
, and year w
t
are assumed to be independent and normally distributed. For each breed, dam weight at age two through ten was estimated as
$$CowWeightAtWea{n_{it}} = {\theta _1} + \sum\limits_{n = 2}^4 {{\theta _i}CowBree{d_{it}} + } {\theta _5}CowAg{e_{it}} + {\theta _6}CowAge_{it}^2 + {\gamma _{it}} + {\omega _i}$$
where ω i is random effect by cow. These cow weights were used to simulate calf birth weight, calving interval, and calf weaning weight.
2.1.4. Simulated Returns
To compute revenue by dam and sire breed, birth weight, calving interval, and weaning weight models were calculated using equations (2)–(5) using mean values of right-hand-side variables for each breed and dam age. Nine combinations of dam and sire breeds were included in the calculations. First, cow weights were simulated using equation(5). Second, bull and heifer birth weights were simulated using the regression results from equation(2) and cow weights from (5). Third, using the calculated cow weights and birth weights, calving intervals were calculated using equation(3). Last, using prior simulated values, weaning weights by dam and sire breeds for steer and heifer calves were calculated using equation(4). These results, along with 2010–2019 calf priceFootnote 4 data from Oklahoma auctions (Livestock Marketing Information Center, 2020), were used to calculate heifer and steer revenues by year, cow age, dam breed, and sire breed. The number of heifers sold was adjusted to account for heifers retained as replacements for culled cows. Using cow weights for each breed and age and the percent of cows culled by age (taken from Azzam et al., Reference Azzam, Azzam, Nielsen and Kinder1990), expected cull cow revenue was computed and included in annual revenue.
An age distribution of cows, taken from Azzam et al. (Reference Azzam, Azzam, Nielsen and Kinder1990) as modified by Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018), was used to weight the distribution of calf weaning weights and revenues based on dam age. Revenues were then averaged across the 10 years. Based on the culling model, 19 heifers were retained annually for 100-head breeding herd. We assumed 85% of the retained heifers breed with the balance culled as feeder heifersFootnote 5 .
3. Data
Data on cows, bulls, calves, and calving season were collected from North Dakota State University’s Dickenson Research Extension Center (DREC) research herd. In the 1990s, DREC started discussing the benefits of small cows versus large cows and began breeding larger heifers to several breeds, including Angus, Red Angus, and Aberdeen bulls. DREC’s research focused on comparing breed efficiency. Data were collected from 2001 to 2018 and consisted of 1,204 observations from primarily spring-calving cowsFootnote 6 with lineage from each of the three Angus-derived breeds and other beef breeds. Data included sire of dam breed, dam birth date, sire breed, calf birth date, calf sex, calf birth weight, calf weaning date, calf weaning weight, dam weight at weaning, and dam body condition score. Summary statistics for the data are shown in Table 1. As average daily gains of nursing calves are critically important in determining weaning weights, these are reported in Table 2.
Table 1. Summary statistics (n = 1204)
Table 2. Average daily gain (lb/day) for nursing calves a
a ADG was calculated from birth to weaning using the DREC data set.
AN = Angus-influenced; AR = Red Angus-influenced; LO = America Aberdeen-influenced.
Feeder calf and cull cow prices from North Dakota (LMIC, 2020) and the age distribution model were used to calculate weaned calf, cull feeder heifer, and cull cow revenues. Pasture, hay, and protein supplementation requirements were calculated using CowCulatorFootnote 7 (Lalman and Gill, Reference Lalman and Gill2013). The feed requirement calculations are based on cow weight, stage of gestation/lactation, body condition score, and target body condition score.Footnote 8 Given the climate in western North Dakota, cows were assumed to graze smooth brome grass pastures for 7 months and fed hay for the remaining 5 months each year. Protein in the form of 20% range cubes was used to supplement protein as required. Rations were computed for each breed by cow age and month of the year, resulting in 360 rations. Annual requirements for pasture, hay, and protein were computed by summing across months by age and breed.
Smooth brome grass pasture yields varied from 1500–2700 pounds per acre (Manske, Reference Manske2018). Using a pasture utilization rate of 25% (Meehan et al., Reference Meehan, Sedivec, Printz and Brummer2018), acres of pasture were computed for each breed and cow age by month under each of the grass yields. Acreage requirements were then multiplied by the age distribution model to generate a weighted average acreage requirement by dam breed, that is, acres of pasture per cow. Pasture utilization rates were then varied from 25% to 50% to assess the sensitivity of the model to this parameter.
Hay was assumed fed from October through March with an 80% utilization rate (Sexten et al., Reference Sexten, Moore, McMurphy, Mourer, Linneen, Brown, Richards and Lalman2021). Dividing the annual hay requirement by 0.8 generated annual hay purchases for each breed and age. Then, the distributions of hay purchases were weighted by the age distribution and summed to generate the weighted average hay purchased, that is, pounds of hay fed per cow. Pounds of protein (20% range cubes) fed were similarly computed, assuming a 100% utilization rate. USDA National Agriculture Statistics data were used for North Dakota pasture lease rates and hay prices (USDA, 2019). Protein (20% range cube) prices were from Stillwater Milling Company (2020). Per head cow fixed and variable costs were taken from Doye and Lalman (Reference Doye and Lalman2011) based on cow weight. Percent calf crop was set at 85% (UNL, 2015).
4. Results and Discussion
4.1. Regression Results
Calf birth weight, calving interval, and calf weaning weight models were estimated using PROC MIXED in SAS Enterprise Guide 9.4 (SAS Institute Inc., 2012). Results for the four models are discussed below.
4.1.1. Birth Weight
The coefficient estimates, standard errors, and level of significance for the calf birth weight model are shown in Table 3. The coefficient for cow weight at previous weaning (
${ CowWeightAtWean}_{i,t-1}$
) is positive and statistically significant, implying larger cows birthed heavier calves. The coefficient for cow age (
${ CowAge}$
) is positive and statistically significant, and the coefficient for cow age squared (
${ CowAge}^{2}$
) is negative and statistically significant. Taken together, birth weight increased in cow age up to age six and then declined. Of the sire breeds, only the Aberdeen coefficient (
${ LO}$
) is statistically significant, decreasing birth weight by 5.0 pounds relative to Angus sires. The Aberdeen-influenced dam coefficient (
$C\_ { LO}$
) is also negative and statistically significant, decreasing birth weight by 9.4 pounds relative to Angus-influenced dams. Heifer calves were 6.2 pounds lighter than bull calves.
Table 3. Regression results for birth weight (lb), natural log calving interval (days), and weaning weight (lb)
a Fixed effects for year omitted for brevity.
b Dam breeds are Angus influence (base), Red Angus-influenced, and American Aberdeen-influenced.
*P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001.
4.1.2. Calving Interval
The coefficient estimates for the natural logarithm of calving interval (
${ LnCalvingInterval}$
) model are also shown in Table 3. The coefficient for calf birth weight divided by cow’s weight at weaning of previous calf (
${ BirthWeightRatio}_{i,t-1}$
) was positive and significant at P ≤ 0.001. Heavy calves relative to dam weight increased the following calving interval similar to the findings of Frazier et al. (Reference Frazier, Sprott, Sanders, Dahm, Crouch and Turner1999). This may be due to increased nutritional demands during pregnancy delaying breeding and/or increased damage to the reproductive tract during calving. Average daily gain of the previous calf (
${ ADG}_{t-1}$
) is negative and significant at the P ≤ 0.05 level. Frazier et al. (Reference Frazier, Sprott, Sanders, Dahm, Crouch and Turner1999) also reported that calving interval decreased as weaning weight increased. This may be due to higher metabolic efficiency of the dam leading to both higher ADG of her calves and shorter calving interval.
4.1.3. Calf Weaning Weight
The coefficient estimates for the calf weaning weight model (
${ CalfWeaningWeight}$
) are shown in Table 3. The coefficient for calf birth weight (
${ CalfBirthWeight}$
) was positive and statistically significant. Heavier calves at birth are heavier at weaning, with each pound of birth weight adding 2.3 pounds of weaning weight. The coefficient for cow body condition score (BCS) at the previous calf weaning (
${ CowBCSatWean}_{t-1}$
) was negative and statistically significant. This result seems counter intuitive but may be related to lower milk production. Cows producing less milk may be better able to maintain BCS but wean lighter calves. The coefficient for cow weight at weaning (
${ CowWeightAtWean}$
) was positive and statistically significant, meaning heavier cows wean heavier calves. The coefficient for cow age (
${ AgeAtCalving}$
) was positive and statistically significant. The coefficient for cow age squared (
${ CowAge}^{2}$
) is negative and statistically significant. Combined these two coefficients indicate that cows weaned their heaviest calves at age six or seven. Both of the two reported sire breeds were statistically significant. At weaning, Red Angus-sired calves were 15.2 pounds lighter at weaning and Aberdeen-sired calves were 56.8 pounds lighter on average, than Angus-sired calves. Calf sex coefficient (
${ CalfSex}$
) was negative and statistically significant, indicating heifer weaning weight was 26.9 pounds lighter than steer weaning weight.
4.1.4. Dam Weight at Weaning
Table 4 provides the regression results for dam weight at weaning (equation 5) by breed and age. Coefficients for cattle breeds were negative and statistically significant when compared to the base dam breed, Angus-influenced. The coefficient for dam age was positive and statistically significant, while the coefficient for dam age squared was negative and statistically significant. This implies that dam weight at weaning increases up to about age ten and then declines; however, most cows are culled at or before age ten. These regression results were used to simulate dam weights for each breed from ages two through ten.
Table 4. Regression results for dam weight (lb) at weaning by breed and age (n = 1,203)
a Angus-influenced dam base. Other breeds omitted for brevity.
*P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001.
4.1.5. Simulation Results
Using the regression estimates from the birth weight equation(2) and dam weights (5), birth weights were simulated. Average daily gain varied depending on sire and dam breeds (see Table 2). Body condition score was held at 5.5 at calving and 5.0 at weaning (OSU, 2021). Other variables were held at breed mean values. Table 5 reports the simulated birth weights by dam and sire breed and age of dam. As expected, younger cows birth lighter calves, calf birth weight peaks at cow age 6–7. For an Angus dam and Angus sire, bull calf birth weights range from 79 to 96 pounds as the dam age increases from two to six, and heifer birthweights range from 73 to 89 pounds. For a Red Angus dam and Red Angus sire, bull calf birthweights range from 81 to 97 pounds, and heifer birth weights range from 75 to 91 pounds. For an Aberdeen-influenced dam and Aberdeen sire, bull calf birth weights range from 64 to 80 pounds, and heifer birthweights range from 58 to 74 pounds. There is about a ten-pound increase in birth weight for Angus and Red Angus-sired calves compared to Aberdeen.
Table 5. Simulated steer and heifer calf birth weight (lb)
AN = Angus-influenced; AR = Red Angus-influenced; LO = American Aberdeen-influenced.
Using the regression estimates for equation(3) and simulated dam weights and calf birth weights, calving intervals were simulated for each dam breed × sire breed for cow ages two through ten. Little difference was observed in calving intervals by dam age. No significant difference was found for dam and sire breeds. However, the heavier a dam’s previous calf was relative to her weight, the longer the calving interval.
4.1.6. Simulated Calf Weaning Weights
Using the regression estimates from equation(4) and simulated cow weight, birth weights, and calving intervals, weaning weights were simulated. Table 6 shows simulated steer and heifer weaning weights. As expected, first-calf heifers and young cows wean lighter calves because younger cows are still growing and likely not producing as much milk as older, mature cows (Andresen et al., Reference Andresen, Wiseman, McGee, Goad, Foote, Reuter and Lalman2020). The weaning weights peak at dam ages 6–7. As expected, heifer weaning weights are about 40 pounds lighter than steer calf weaning weights. Of course, calves from LO sires and/or dams weigh substantially less at weaning than the other Angus-derived breeds. Table 7 reports simulated weaning weight to cow weight ratios. The heaviest ratios are Aberdeen-influenced dams × Angus or Red Angus sires. The lightest ratios are from Aberdeen sires.
Table 6. Simulated steer and heifer calf weaning weight (lb)
AN = Angus-influenced; AR = Red Angus- influenced; LO = American Aberdeen-influenced.
Table 7. Simulated weaning weight to cow weight ratios
AN = Angus-influenced; AR = Red Angus-influenced; LO = American Aberdeen-influenced.
4.1.7. Simulated Revenues, Costs, and Returns
Calf sales and cull cow revenues by dam breed are given in Table 8. As expected, revenue per head has a similar pattern as calf weaning weights. Angus- and Red Angus-influenced dams earned, on a per head average, more than Aberdeen-influenced dams regardless of sire breed. Both Angus and Red Angus calf revenues and cull revenues were always higher than the American Aberdeen-influenced dams. These results were driven, primarily, by weights. Heavier Angus- and Red Angus-influenced cows weaned heavier calves and, so, both cull cow and calf revenues were higher. The average revenues during the 10-year period were likely rather high in comparison to other historical returns.
Table 8. Annual revenues ($/hd) by dam and sire breed
a Cows are not purebred, rather influence or “percentage.”
There is one caveat needed. As Aberdeen Angus cows and bulls are smaller-framed, there is the possibility of frame score 3 (FS3) calves. Small-framed calves are often discounted in the sale barn. Newport (Reference Newport2013) reported small-framed calves sold for $22 per head less than comparable larger-framed calves. The data do not include calf frame scores. However, some evidence is available from the regression models. Percentage Aberdeen cows had 23-pound lighter calves at weaning (Table 3) but Aberdeen sires had calves weighing 57 pounds less than Angus-sired calves. Further, Aberdeen-influenced cows weighed 241 pounds less than Angus-influenced cows. So, it seems unlikely that the Aberdeen-influenced cows bred to Angus or Red Angus bulls had FS3 calves. Conversely, it does seem likely that Aberdeen-influenced dams bred to Aberdeen bulls did produce some percentage, perhaps a majority, FS3 calves. So, we apply the $22 per head discount from Newport (Reference Newport2013) to the Aberdeen-sired calves from Aberdeen influence cows.
Assuming a yield of 2100 pounds of smooth bromegrass per acre, weighted average required pasture acres over 7 months were 24 acres for Angus, 24.3 acres for Red Angus, and 20.3 acres for Aberdeen cows.Footnote 9 Table 9 provides the calculated feed expenses showing Angus cows, on average, cost $640 to feed per year, while Red Angus cows required $645 in feed costs, and Aberdeen cows required $593. These costs are driven by the differences in weight between the breeds. It was assumed that one bull was needed for every 25 cows. Per head costs for owning a bull were estimated to be $50, assuming a bull cost $3,000 with a $1000 salvage value, depreciated over 5 years, and required $850 in feed and veterinary expenses annually. Table 9 also reports other variable expenses (veterinary, marketing, labor, etc.) and fixed costs per head.
Table 9. Weighted average feed quantities and costs and other costs by dam breed a
a Assumes smooth bromegrass yields of 2100 lb per acre.
AN = Angus-influenced; AR = Red Angus-influenced; LO = American Aberdeen-influenced.
As expected, sire breeds × dam breeds that weaned heavier calves, received higher revenue per head. Red Angus-sired calves we slightly heavier at weaning than other calves and Red Angus cull cows weighed more at culling, resulting in higher per head revenue. Of course, Aberdeen-sired calves were lighter weight, and these mating systems earned the least revenue per head. Aberdeen-influenced cows weaned lighter calves, earning the lower revenue than Angus- and Red Angus-influenced cows.
Red Angus bulls generated the highest returns per head between the three sire breeds. Calves from the Red Angus sires were slightly heavier than Angus-sired calves and much heavier than Aberdeen-sired calves, resulting in higher returns per head. Somewhat unexpectedly, Aberdeen-influenced cows having higher per head returns than the other dam breeds with the same sire breed in several grass yield scenarios. Across the grass yield scenarios, the highest per head return breeding system was Red Angus sires on Aberdeen-influenced cows. The difference in returns per head is largest in low grass yield scenarios as the larger-framed cows required relatively more acres per head. These results are driven largely by weaning rate ratios and cow feed costs. The highest weaning rate ratios (Table 8) were with Red Angus sires with Aberdeen-influenced cows. With Aberdeen cows having the lower cost per head (Table 9) and higher wean weight ratios with Red Angus bulls, return per head for this paring are higher than other breeding systems.
However, producers are constrained by grazing acres, so net returns per head are often a misleading measure of profitability.Footnote 10 Rather, the ability to generate higher returns per acre is the appropriate metric as in equation(1). So, the returns per head reported in Table 10 were divided by the acres required per head to generate returns per acre. These returns are reported in Table 11.
Table 10. Weighted average returns to fixed costs, labor, and management ($/hd) by dam and sire breed and pasture yield (lb/ac)
AN = Angus-influenced; AR = Red Angus-influenced; LO = American Aberdeen-influenced.
Table 11. Weighted average returns to fixed costs, labor, and management ($/ac) by dam and sire breed and pasture yield (lb/ac)
AN = Angus-influenced; AR = Red Angus-influenced; LO = American Aberdeen-influenced.
When normalized on acres required per head, there are advantages for the Aberdeen-influenced cow bred to Angus or Red Angus sires. The Aberdeen dam bred to a Red Angus sire generated the highest per acre returns with a $1–$6 per acre advantage over an Angus sire. Angus and Red Angus sires had very similar results, with $1 per acre of each and certainly with the confidence of our model results Aberdeen-sired calves were the lowest returning. These matings had the lowest weaning weights, resulting in low per head and per acre returns. Robustness of these results was evaluated by varying grazing efficiency and hay feeding loss. Neither change the qualitative conclusions. Improved grazing utilization improves profitability of all breeds and favors Aberdeen-influenced cows. Improved hay feeding efficiency improves profitability of all breeds with negligible impact on relative returns.
5. Conclusions and Implications
We investigated the differences in profitability between Angus, Red Angus, and Aberdeen-influenced beef cow herds due to birth weight, calving interval, weaning weight, and feed expense. Regression models of calving weights, calving intervals, and calf weaning weights were estimated by cow breed using data from the Dickinson Research Extension Center. Using these models, revenues by dam and sire breed were simulated for 10 years of price data. Pasture, hay, and protein supplementation needs were estimated using Cowculator (Lalman and Gill, Reference Lalman and Gill2013), and associated feed costs were calculated by breed. Returns to fixed costs, labor, and management were computed by sire breed and dam breed, resulting in nine sire by dam breed returns.
Using Angus and Red Angus sires, results indicate there are differences in returns per acre across the three cow breeds when measured in the more appropriate metric, dollars per acre. Smaller cows bred to Red Angus bulls resulted in the highest returns across all grass yield scenarios, by $1–$6 per acre. This mating resulted in the highest weaning weight to cow weight ratios (Table 7) and the lowest per cow (Table 9). Although calves weaned from this mating were lighter than calves from Angus-influenced and Red Angus-influenced dams, the reduction in feed cost and higher stocking rate offset the lower weaning weight. However, while confidence intervals were beyond the scope of our model, the differences in returns are likely not statistically significant.
A couple of strong caveats are necessary. Feed costs were simulated and not benchmarked to this herd’s data. Nutritional requirements for Aberdeen-influenced cows in comparison to other beef breeds have not been established. So, we used standard assumptions for feed intake based on weight and known Angus requirements. However, there is potential that differences in selection pressures have resulted in differences in metabolic efficiency between the three breeds—differences that cannot be accounted for with just cow weight, stages of gestation and lactation, and cow age.
Also, a caution is needed regarding sample size: we have one environment. Cows and calves in other environments will perform better or worse in comparison to the environment in western North Dakota. For example, Russell (Reference Russell2014) found that lighter-weight cows were economically superior in nutritionally challenging environments. The colder North Dakota environment may favor a larger cow. Data from several locations are necessary to fully weigh the relative economic merits of Angus-derived breeds.
As U.S. beef cow herd weights have steadily increased (Wiseman et al., Reference Wiseman, Lalman and DeVuyst2018), there is growing evidence that mature cow size has exceeded the optimal weight for the industry. From cow-calf producer to the consumer, it is reasonable to ask, even speculate, that cow size is heavier than economically optimal. Bir et al. (Reference Bir, DeVuyst, Rolf and Lalman2018) found lighter-weight cows are more profitable than heavier-weight cows. Smaller cows require less forage than larger cows, so stocking rates are higher. Aberdeen-influenced herds can assist in downsizing cow sizes but their genetics might offset the gains from increased stocking rates. Here, our analyses find there a small but likely statistically insignificant economic advantage with Aberdeen-influenced cows bred to Angus or Red Angus sire in comparison to Angus and Red Angus cows. So, we cannot definitely conclude that the smaller-framed Aberdeen-influenced cows have economic advantages over their larger-framed cousins. However, there is no evidence of a disadvantage either.
From an industry perspective, smaller cattle better align with consumer preferences. Behrends et al. (Reference Behrends, Leick, Schilling, Yoder and Schmidt2009) and Maples, Lusk, and Peel (Reference Maples, Lusk and Peel2018) reported consumers were willing to pay a premium for thick cut steaks. However, as cow size increases, so does muscle cross-section area in carcasses. This means steaks must be cut thin to meet portion sizes. The current grading system rewards larger ribeye area as it is an indicator of carcass yield. In short, there are misaligned incentives in the beef sector. The higher value of thick cut, smaller cross-sectional area steaks is not being captured and passed through the chain to cow-calf producers. A marketing channel that captures the higher consumer willingness-to-pay and rewards carcasses with smaller ribeye area could possibly improve sector profits. In that case, Aberdeen-influenced cattle are well suited to match consumer preferences. It is worth noting that center cuts (ribeye, T bone, and sirloin steaks) only comprise about 16% of the meat from a boneless, trimmed beef (SDSU, 2020). So, it may be that larger carcass generate the highest return to the beef sector even accounting for lost value from thinner cut steaks. Before recommending an industry shift, the relative performance of Aberdeen-influenced cattle in feedlots and their carcass merit must be evaluated. Armed with multi-environment cow-calf data, feedlot data, and carcass data, a full assessment of the industry impacts of using smaller-framed breeding stock can be completed.
Financial support
Partial funding for this research was provided by Oklahoma Agricultural Experiment Station, Oklahoma State University, Stillwater, Oklahoma.
Conflict of interest
All authors declare that no competing interests exist.
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