- Email: [email protected]
Fall-breeding beef females failing to conceive during spring breeding
The Professional Animal Scientist 32 (2016):243–247; http://dx.doi.org/10.15232/pas.2015-01457 ©2016 American Registry of Professional Animal Scientists. All rights reserved.
F afailing ll-breeding beef females to conceive during spring breeding
A. Gomes da Silva,*† D. C. Adams,* and R. N. Funston*1 *University of Nebraska–Lincoln West Central Research and Extension Center, North Platte 69101; and †Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
ABSTRACT A study was conducted to evaluate the economics of retaining ownership and rebreeding nonpregnant spring-calving cows to be sold as pregnant fall-calving cows. Spring-born crossbred females diagnosed as nonpregnant after the regular spring breeding season were used over a 2-yr period at 2 locations, Gudmundsen Sandhills Laboratory (GSL) and West Central Research and Extension Center (WCREC). A partial budget analysis was performed to evaluate the economic aspects of this strategy; total cost was calculated by adding the purchase price, feeding and management cost, breeding expenses, and 6% annual interest rate on the purchase price. The net cost of one pregnant cow was calculated as the difference between total cost and cull value, divided by the number of pregnant cows. A sensitivity analysis evaluated the economics of retaining and rebreeding for market scenarios for the last 5 yr at different pregnancy rates. The overall rebreeding pregnancy rate was 86.1% at GSL and 80.0% at WCREC; the percentage of the pregnant cows that conceived in the first 21 d of the breeding season was 84.4% at GSL and 66.6% at WCREC. The increasing cow prices from November to April and a greater market price for pregnant females resulted in Corresponding author: [email protected]
1
a net gain of $520.29 and $616.81 per pregnant female for GSL and WCREC, respectively. Simulation performed using market prices for the last 5 yr demonstrated the strategy is cost effective in different market scenarios, excluding 2012/2013 because of drought—feed prices were the highest and cow prices the lowest of the 5 yr analyzed. Other than atypical scenarios like drought, positive economic results may be possible even at low pregnancy rates, but as the pregnancy rate increases, net proceeds also increase. Key words: culling, fall-calving cows, marketing beef females
INTRODUCTION Probably no single aspect of beef herd management is as complicated, or has potentially greater economic impact, as the cow culling and replacement decision (Melton, 1980). Conventional wisdom has been that nonpregnant beef females should be sold after pregnancy detection to avoid extra feeding expenses. Culling young females for pregnancy failure can be extremely costly to a beef enterprise because they have not yet become profitable (Roberts et al., 2015). Most often, these nonpregnant beef females are culled and sold into the
slaughter market. These sales represent, on average, 10 to 20% of total gross income for the beef producer (Sawyer et al., 2004). The cull cow market has traditionally been seasonal, with October and November monthly average cull cow prices being the lowest for the year because Nebraska beef production is predominantly based on a spring calving system, lending itself to November cow culling. Alternatively, cull beef females may be retained until a period of historically higher market prices and, depending on feed costs, placed on a high energy diet, thus capturing greater weight and prices (Funston et al., 2003). The United States cowherd is at historical low levels, and several offsetting factors support herd expansion, including unprecedented cow–calf returns, ongoing global beef demand growth, and timing within the current cattle cycle (Tonsor and Schulz, 2015). Therefore, the decision not only to replace breeding females but increase retention to ultimately increase beef supplies must also be considered. An alternative replacement or expansion opportunity is keeping the nonpregnant beef female to rebreed. This may not be a traditional option, but the variability in cull cow and feedstuff prices suggests an alternative
244 could exist. Therefore, a study was conducted to evaluate the economics of retaining ownership and rebreeding nonpregnant spring-calving beef females to be sold as pregnant fallcalving cows.
MATERIALS AND METHODS Animals Spring-born crossbred beef females diagnosed nonpregnant after the regular spring breeding season were used over a 2-yr period at 2 locations, the Gudmundsen Sandhills Laboratory (GSL; yr 1, n = 61; yr 2, n = 72; Whitman, NE) and the West Central Research and Extension Center (WCREC; yr 2, n = 15; North Platte, NE). The GSL females were composite Red Angus × Simmental, and approximately 80% were primiparous or entering their first breeding season before the beginning of the study (on average, 25 mo old; ranging from 15 mo to 7 yr old). The GSL females weighed 393 ± 57 kg at the beginning of the study and 452 ± 60 kg when they were sold. The GSL females were exposed for a 45-d natural service breeding season before the beginning of the study. Pregnancy diagnosis was determined by ultrasound in October, 45 d after bull removal. The WCREC heifers were primarily Angus and 15 mo of age. The WCREC heifers weighed 444 ± 60 kg at the beginning of the study and 473 ± 14 when they were sold. Prior to the breeding season they were synchronized with a melengestrol acetate–prostaglandin F2α (PG) protocol before AI, and following AI they were placed with bulls for 60 d. Pregnancy diagnosis was performed in October via rectal ultrasound, 45 d after bulls were removed.
Synchronization Protocol and Rebreeding GSL. Females were synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) on d 0 followed by CIDR removal and PG (Lutalyse, Zoetis) on d 7
Gomes da Silva et al.
before a 60-d natural service breeding season beginning November 13. A 1:25 bull-to-cow ratio was used. Pregnancy diagnosis was determined by ultrasound 30 d after bulls were removed; 2 wk later nonpregnant cows were sold. Pregnant cows were sold 2 mo after pregnancy detection at a local livestock auction. WCREC. Heifers were synchronized with CIDR and gonadotropinreleasing hormone (GnRH; Fertagyl, Intervet Inc., Millsboro, DE) on d 0 followed by CIDR removal and PG on d 7 and AI 60 h later. Estrus detection patches (Estrotect Heat Detectors, Rockway Inc., Spring Valley, WI) were used to detect standing estrus, and the second gonadotropinreleasing hormone injection was administered at fixed-time AI only to heifers that did not have their patches rubbed. Heifers were AI November 11 and after AI were placed with bulls until sold at local livestock auction (approximately 170 d). Pregnancy diagnosis was determined by ultrasound 135 d after AI.
Diet GSL. Hay and supplement (29% CP; 0.90 kg/d per head) were fed from November to February. The cows diagnosed as nonpregnant were sold March 1, and in yr 1 the pregnant cows grazed meadow pastures until April. In yr 2 the pregnant cows were fed hay until they were sold in April. WCREC. Heifers grazed winter range from November to April with a self-fed cooked molasses 30% CP tub, consuming approximately 0.23 kg/d per head. After the rebreeding season, nonpregnant heifers were sold April 14, and the pregnant heifers were sold 2 wk later.
Economic Analysis A partial budget analysis was performed to compare economics of selling nonpregnant cows immediately after pregnancy diagnosis (November) versus rebreeding to be sold as pregnant fall-calving cows in a potentially more favorable market (April).
During the study, hay prices ranged from $99 to $143 in yr 1 and from $83 to $121/t in yr 2; an average hay cost of $121/t for yr 1 and $97.21/t for yr 2 was assumed. Grazing meadow cost per animal was considered to be $1/d, the cost of grazing winter range per animal was also assumed to be $1/d, and basic management and yardage for each female was estimated at $0.30/d. The supplement ($424/t, DM basis) was composed of processed grain by-products, plant protein products, roughage products, calcium carbonate, molasses products, urea, vitamin A supplement, copper sulfate, zinc oxide, magnesium sulfate, and monensin. Average feeding costs per day are presented in Table 1. Cow value at the beginning of the study was calculated from the Nebraska average price reported by the USDA Agricultural Marketing Service for the corresponding date and respective average BW. Total breeding
Table 1. Average feedstuff prices for each location $/d per head Description Hay3 Winter pasture Meadow pasture Supplement4 Yardage
GSL1
WCREC2
1.43 — 1.00 0.18 0.30
— 1.00 — 0.08 —
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE): hay and supplement (0.90 kg/d per head) were fed from November to February. In yr 1 the females grazed meadow pastures March and April. In yr 2 hay and supplement were fed until females were sold in April. 2 West Central Research and Extension Center (WCREC, North Platte, NE): heifers grazed winter range and received supplement (0.23 kg/d per head) from November to April. 3 Hay cost assumed as $121/t for yr 1 and $97.21/t for yr 2. 4 Supplement containing approximately 29% CP, DM priced at $424/t. 1
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Table 2. Average hay and animal prices used in the sensitivity analysis of rebreeding nonpregnant females for market scenarios for the last 5 yr Description Hay ($/t) Cow initial value ($/head) Cull cow ($/head) Pregnant cow ($/head)
cost for GSL females included CIDR (Eazi-Breed CIDR, Zoetis Inc.) cost at $11.25/cow, a single PG injection at $2.87/cow, and labor expense of $5/cow. Breeding cost for the WCREC heifers included CIDR cost at $11.25/heifer, a single PG injection at $2.87/heifer, GnRH injection at $2.68/injection, estrus detection aids at $1.16/patch, semen at $25/dose, and technician expense of $8/cow. Total cost was calculated by adding the purchase price, total feeding cost, breeding expenses, and 6% annual interest rate on the purchase price. The net cost of one pregnant cow was calculated as the difference between total cost and cull value, divided by the number of pregnant cows. Net gain was calculated as the difference between pregnant female price and net cost.
Sensitivity Analysis A sensitivity analysis evaluated the economics of retaining and rebreeding
2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
76.68 929.07 1,055.46 1,749.32
106.98 1,175.50 1,280.63 2,003.20
235.09 1,157.69 1,062.15 1,390.00
121.22 874.97 1,324.05 1,699.25
97.21 1,396.13 1,615.83 2,420.20
strategy for market scenarios for the last 5 yr (2010/2011 to 2014/2015) at different pregnancy rates. An analysis was performed for each location (WCREC and GSL), considering the WCREC heifers were timed AI and the GSL heifers were synchronized and placed with bulls for 60 d. Heifers were considered to be 15 mo old for both locations. Feeding was assumed to be similar for the 2 locations, hay and supplement for a 160-d period. Average hay prices for each year were obtained from the Nebraska average price reported by the USDA Agricultural Marketing Service (2010–2015). Cow and heifer values in November, March, and April were calculated from the Nebraska average price reported by the USDA Agricultural Marketing Service (2010–2015) for the corresponding date and respective average BW. Average hay and animal prices used in the sensitivity analysis are presented in Table 2. Total breeding costs were assumed to be similar
Table 3. Reproductive performance in the rebreeding season Description
GSL1
WCREC2
n AI pregnancy rate (%) Overall pregnancy rate (%) Conceived in the first 21 d (%)
133 — 86.1 84.4
15 53.3 80.0 66.6
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE): cows were synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) on d 0 followed by CIDR removal and prostaglandin F2α (PG; Lutalyse, Zoetis) on d 7 before a 60-d natural service breeding season, 1:25 bull-to-cow ratio. 2 West Central Research and Extension Center (WCREC, North Platte, NE): heifers were synchronized with CIDR and gonadotropin-releasing hormone (Fertagyl, Intervet Inc., Millsboro, DE) on d 0 followed by CIDR removal and PG on d 7 and AI 60 h later. After AI, heifers were placed with bulls for 170 d. 1
each year. Breeding expenses for GSL females included CIDR, a single PG injection, and labor. Breeding cost for the WCREC heifers included CIDR, PG, GnRH, heat detectors, semen, and technician labor.
RESULTS AND DISCUSSION The overall pregnancy rate was 86.1% at GSL and 80.0% at WCREC (Table 3). A high percentage conceived in the first 21 d of the breeding season (84.4 and 66.6% at GSL and WCREC, respectively). Females calving earlier in the calving season will be more adaptable to the fall calving system and be more productive as fall-calving cows (Cushman et al., 2013). The partial budget analysis of rebreeding a female that would be culled is presented in Table 4. The total cost per female was $1,487.62 and $1,703.76 for GSL and WCREC, respectively. Feeding expenses were lower for WCREC heifers because no hay and a minimal amount of supplement were fed. Rebreeding expenses were lower for GSL because the cows and heifers were not AI. An important breeding expense in natural breeding systems is bull cost; nevertheless, it was not included in the breeding expenses in this study because it was assumed the operation already had bulls not in use after the spring breeding season. An alternative approach to calculate the bull cost is to divide the costs for the 2 breeding seasons. In this scenario, the rebreeding season has the additional advantage of increased bull use, reducing the breeding costs of the regular breeding season.
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Table 4. Partial budget analysis of rebreeding a nonpregnant beef female $/beef female Description Initial value (November) (re)Breeding expenses3 Feeding expenses4 Interest (6%) Total cost Cull cow value (March) Net cost Sale value (April) Net gain
GSL1
WCREC2
1,168.89 19.12 270.58 29.03 1,487.62 1,475.45 1,502.71 2,023.00 520.29
1,422.41 57.63 188.16 35.56 1,703.76 1,549.26 1,742.38 2,359.19 616.81
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE; cows and heifers). West Central Research and Extension Center (WCREC, North Platte, NE; heifers). 3 Breeding expenses include for GSL cost of technician, controlled internal drugrelease insert (CIDR; Zoetis, Florham Park, NJ), and prostaglandin F2α (Lutalyse, Zoetis) and for WCREC cost of technician, semen, CIDR, prostaglandin F2α, heat detectors, and gonadotropin-releasing hormone. 4 Feeding expenses for approximately 160 d for GSL yr 1: hay and supplement from November to February and meadow pastures from March to April; for GSL yr 2: hay and supplement from November to February and hay from March to April; and for WCREC (yr 2): winter range and supplement from November to April. 1 2
Another bull-related expense that might increase breeding costs is the necessity of retesting the bulls before the rebreeding season for trichomoniasis. Trichomoniasis is associated with early-term abortions and reduction in revenue because of pregnancy losses (Rae, 1989). The low cost of testing breeding bulls compared with the magnitude of losses this disease can cause suggests that retesting for trichomoniasis may be a prudent decision.
Despite the differences in breeding and feeding costs between the 2 locations, the difference in the total cost between locations is primarily due to initial price. Heifers at WCREC were all 15 mo of age and had higher market price per hundredweight in November compared with older females that made up 20% of the GSL females. The best candidates for this strategy, in fact, are young females, such as
heifers and primiparous cows. Those females have more productive life remaining and the greatest potential for added value when sold later as a pregnant cow compared with its current value as a cull cow. Although younger females have higher risk of being culled due to pregnancy failure with their second and third calves, older cows have less productive life remaining, and it is less likely there would be enough extra value to capture to make the strategy profitable. The remaining nonpregnant females were sold in March, and they had a market price lower than the total cost for both locations (Table 4), adding to the net cost. Thus, as the percentage of nonpregnant cows increases or the value of these animals decreases, the net cost per pregnant female increases. Pregnant cows sold in April increased in value compared with November prices by approximately 73 and 66%, for GSL and WCREC, respectively. The increasing cattle prices from November to April and a greater market price for pregnant females resulted in a net gain of $520.29 and $616.81 per pregnant female for GSL and WCREC, respectively. The higher net gain for WCREC is due to the greater sale price for pregnant heifers compared with older pregnant cows. In addition to the seasonality of the market, the value difference between slaughter and pregnant cows is mainly responsible for making the strategy presented in this study profitable.
Table 5. Sensitivity analysis of rebreeding nonpregnant females for market scenarios for the last 5 yr at different pregnancy rates—GSL Pregnancy rate (%) 10 30 50 70 90
Net proceeds ($/heifer exposed; GSL—NSB)1 2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
−92.16 52.44 197.03 341.62 486.21
−207.67 −55.82 96.02 247.86 399.71
−802.44 −730.17 −657.91 −585.65 −513.38
63.66 147.12 230.59 314.05 397.51
−84.79 85.58 255.95 426.31 596.68
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE) natural service breeding (NSB): synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) on d 0 followed by CIDR removal and prostaglandin F2α (Lutalyse, Zoetis) on d 7 before a 60-d NSB season, 1:25 bull-to-cow ratio. Feeding was considered to be hay and supplement for a 160-d period.
1
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Rebreeding beef females
Table 6. Sensitivity analysis of rebreeding nonpregnant females for market scenarios for the last 5 yr at different pregnancy rates—WCREC Pregnancy rate (%) 10 30 50 70 90
Net proceeds ($/heifer exposed; WCREC—TAI)1 2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
−91.01 35.56 162.14 288.72 415.29
−206.05 −76.86 52.34 181.54 310.73
−860.31 −808.62 −756.94 −705.26 −653.57
92.52 150.11 207.69 265.27 322.86
−57.27 83.81 224.89 365.97 507.05
West Central Research and Extension Center (WCREC, North Platte, NE) fixed-time AI (TAI): synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) and gonadotropin-releasing hormone (Fertagyl, Intervet Inc., Millsboro, DE) on d 0 followed by CIDR removal and prostaglandin F2α (Lutalyse, Zoetis) on d 7 before TAI. After TAI 60 h later, heifers were placed with bulls for approximately 170 d. Feeding was considered to be hay and supplement for a 160-d period.
1
The data presented in Table 4 indicate that delayed selling of cull cows is not a highly profitable strategy. If, instead of rebreeding the nonpregnant spring-calving cows, we had simply retained to sell as slaughter cows in March, we would have a $6.95/head profit for GSL and $96.87/head loss for WCREC. Despite the seasonal behavior of the market, with high prices in March and April and lows from September to November, the costs for feeding during this period can equalize or even overcome greater cow prices. Small operations, depending on the number of cull cows, may find that the extra labor and expense of keeping them throughout the winter may outweigh the benefit. The sensitivity analysis is presented in Tables 5 and 6 for GSL and WCREC, respectively. Considering feeding costs the same for both locations and considering all animals as 15-mo heifers, GSL had the greatest return. However, when available, less expensive feeding strategies should be considered to improve economic return. Because of additional costs with AI, the natural service breeding had reduced breeding costs, increasing the net proceeds per heifer exposed at a given pregnancy rate. In the present study all females were sold at livestock auction, and AI pregnant
females were not valued differently than females pregnant by natural service. Furthermore, the USDA Agricultural Marketing Service does not provide alternative prices for females pregnant via AI or natural service. If higher market prices exist for AI pregnant heifers and cows and exceed the increased AI costs, it is recommended to use AI to increase profits. The rebreeding strategy was not cost effective in the 2012/2013 scenario. As a result of the 2012 drought, feedstuff prices in 2012 were greatest and market prices lowest; consequently, production costs were greater than gross proceeds. As a result, in 2012/2013 this management practice was not profitable, regardless of pregnancy rate. With the exception of 2012/2013, the strategy appears to be cost effective even at a modest pregnancy rate. However, as pregnancy rate increases, net proceeds increase.
IMPLICATIONS In the present study, satisfactory reproductive and economic performances were achieved by retaining nonpregnant females and rebreeding for a fall calving season. The strategy provides an alternative to potentially increase financial returns with cull beef females.
LITERATURE CITED Cushman, R. A., L. K. Kill, R. N. Funston, E. M. Mousel, and G. A. Perry. 2013. Heifer calving date positively influences calf weaning weights through six parturitions. J. Anim. Sci. 91:4486–4491. Funston, R. N., J. A. Paterson, K. E. Williams, and A. J. Roberts. 2003. Effect of body condition, initial weight and implant on feedlot and carcass characteristics of cull cows. Prof. Anim. Sci. 19:233–238. Melton, E. B. 1980. Economics of beef cow culling and replacement decisions under genetic progress. West. J. Agric. Econ. 5:137–147. Rae, D. O. 1989. Impact of trichomoniasis on the cow-calf producer’s profitability. J. Am. Vet. Med. Assoc. 194:771–775. Roberts, A. J., M. K. Petersen, and R. N. Funston. 2015. Beef Species Symposium: Can we build the cowherd by increasing longevity of females? J. Anim. Sci. 93:4235–4243. http://dx.doi.org/10.2527/jas.2014-8811. Sawyer, J. E., C. P. Mathis, and B. Davis. 2004. Effects of feeding strategy and age on live animal performance, carcass characteristics, and economics of short-term feeding programs for culled beef cows. J. Anim. Sci. 82:3646–3653. Tonsor, G. T., and L. L. Schulz. 2015. Beef Species Symposium: Economic considerations related to U.S. beef herd expansion. J. Anim. Sci. 93:4227–4234. http://dx.doi.org/10.2527/ jas.2014-8473. USDA Agricultural Marketing Service. 2010–2015. Nebraska Livestock Custom Report. https://marketnews.usda.gov/mnp/ ls-report-config.
F afailing ll-breeding beef females to conceive during spring breeding
A. Gomes da Silva,*† D. C. Adams,* and R. N. Funston*1 *University of Nebraska–Lincoln West Central Research and Extension Center, North Platte 69101; and †Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
ABSTRACT A study was conducted to evaluate the economics of retaining ownership and rebreeding nonpregnant spring-calving cows to be sold as pregnant fall-calving cows. Spring-born crossbred females diagnosed as nonpregnant after the regular spring breeding season were used over a 2-yr period at 2 locations, Gudmundsen Sandhills Laboratory (GSL) and West Central Research and Extension Center (WCREC). A partial budget analysis was performed to evaluate the economic aspects of this strategy; total cost was calculated by adding the purchase price, feeding and management cost, breeding expenses, and 6% annual interest rate on the purchase price. The net cost of one pregnant cow was calculated as the difference between total cost and cull value, divided by the number of pregnant cows. A sensitivity analysis evaluated the economics of retaining and rebreeding for market scenarios for the last 5 yr at different pregnancy rates. The overall rebreeding pregnancy rate was 86.1% at GSL and 80.0% at WCREC; the percentage of the pregnant cows that conceived in the first 21 d of the breeding season was 84.4% at GSL and 66.6% at WCREC. The increasing cow prices from November to April and a greater market price for pregnant females resulted in Corresponding author: [email protected]
1
a net gain of $520.29 and $616.81 per pregnant female for GSL and WCREC, respectively. Simulation performed using market prices for the last 5 yr demonstrated the strategy is cost effective in different market scenarios, excluding 2012/2013 because of drought—feed prices were the highest and cow prices the lowest of the 5 yr analyzed. Other than atypical scenarios like drought, positive economic results may be possible even at low pregnancy rates, but as the pregnancy rate increases, net proceeds also increase. Key words: culling, fall-calving cows, marketing beef females
INTRODUCTION Probably no single aspect of beef herd management is as complicated, or has potentially greater economic impact, as the cow culling and replacement decision (Melton, 1980). Conventional wisdom has been that nonpregnant beef females should be sold after pregnancy detection to avoid extra feeding expenses. Culling young females for pregnancy failure can be extremely costly to a beef enterprise because they have not yet become profitable (Roberts et al., 2015). Most often, these nonpregnant beef females are culled and sold into the
slaughter market. These sales represent, on average, 10 to 20% of total gross income for the beef producer (Sawyer et al., 2004). The cull cow market has traditionally been seasonal, with October and November monthly average cull cow prices being the lowest for the year because Nebraska beef production is predominantly based on a spring calving system, lending itself to November cow culling. Alternatively, cull beef females may be retained until a period of historically higher market prices and, depending on feed costs, placed on a high energy diet, thus capturing greater weight and prices (Funston et al., 2003). The United States cowherd is at historical low levels, and several offsetting factors support herd expansion, including unprecedented cow–calf returns, ongoing global beef demand growth, and timing within the current cattle cycle (Tonsor and Schulz, 2015). Therefore, the decision not only to replace breeding females but increase retention to ultimately increase beef supplies must also be considered. An alternative replacement or expansion opportunity is keeping the nonpregnant beef female to rebreed. This may not be a traditional option, but the variability in cull cow and feedstuff prices suggests an alternative
244 could exist. Therefore, a study was conducted to evaluate the economics of retaining ownership and rebreeding nonpregnant spring-calving beef females to be sold as pregnant fallcalving cows.
MATERIALS AND METHODS Animals Spring-born crossbred beef females diagnosed nonpregnant after the regular spring breeding season were used over a 2-yr period at 2 locations, the Gudmundsen Sandhills Laboratory (GSL; yr 1, n = 61; yr 2, n = 72; Whitman, NE) and the West Central Research and Extension Center (WCREC; yr 2, n = 15; North Platte, NE). The GSL females were composite Red Angus × Simmental, and approximately 80% were primiparous or entering their first breeding season before the beginning of the study (on average, 25 mo old; ranging from 15 mo to 7 yr old). The GSL females weighed 393 ± 57 kg at the beginning of the study and 452 ± 60 kg when they were sold. The GSL females were exposed for a 45-d natural service breeding season before the beginning of the study. Pregnancy diagnosis was determined by ultrasound in October, 45 d after bull removal. The WCREC heifers were primarily Angus and 15 mo of age. The WCREC heifers weighed 444 ± 60 kg at the beginning of the study and 473 ± 14 when they were sold. Prior to the breeding season they were synchronized with a melengestrol acetate–prostaglandin F2α (PG) protocol before AI, and following AI they were placed with bulls for 60 d. Pregnancy diagnosis was performed in October via rectal ultrasound, 45 d after bulls were removed.
Synchronization Protocol and Rebreeding GSL. Females were synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) on d 0 followed by CIDR removal and PG (Lutalyse, Zoetis) on d 7
Gomes da Silva et al.
before a 60-d natural service breeding season beginning November 13. A 1:25 bull-to-cow ratio was used. Pregnancy diagnosis was determined by ultrasound 30 d after bulls were removed; 2 wk later nonpregnant cows were sold. Pregnant cows were sold 2 mo after pregnancy detection at a local livestock auction. WCREC. Heifers were synchronized with CIDR and gonadotropinreleasing hormone (GnRH; Fertagyl, Intervet Inc., Millsboro, DE) on d 0 followed by CIDR removal and PG on d 7 and AI 60 h later. Estrus detection patches (Estrotect Heat Detectors, Rockway Inc., Spring Valley, WI) were used to detect standing estrus, and the second gonadotropinreleasing hormone injection was administered at fixed-time AI only to heifers that did not have their patches rubbed. Heifers were AI November 11 and after AI were placed with bulls until sold at local livestock auction (approximately 170 d). Pregnancy diagnosis was determined by ultrasound 135 d after AI.
Diet GSL. Hay and supplement (29% CP; 0.90 kg/d per head) were fed from November to February. The cows diagnosed as nonpregnant were sold March 1, and in yr 1 the pregnant cows grazed meadow pastures until April. In yr 2 the pregnant cows were fed hay until they were sold in April. WCREC. Heifers grazed winter range from November to April with a self-fed cooked molasses 30% CP tub, consuming approximately 0.23 kg/d per head. After the rebreeding season, nonpregnant heifers were sold April 14, and the pregnant heifers were sold 2 wk later.
Economic Analysis A partial budget analysis was performed to compare economics of selling nonpregnant cows immediately after pregnancy diagnosis (November) versus rebreeding to be sold as pregnant fall-calving cows in a potentially more favorable market (April).
During the study, hay prices ranged from $99 to $143 in yr 1 and from $83 to $121/t in yr 2; an average hay cost of $121/t for yr 1 and $97.21/t for yr 2 was assumed. Grazing meadow cost per animal was considered to be $1/d, the cost of grazing winter range per animal was also assumed to be $1/d, and basic management and yardage for each female was estimated at $0.30/d. The supplement ($424/t, DM basis) was composed of processed grain by-products, plant protein products, roughage products, calcium carbonate, molasses products, urea, vitamin A supplement, copper sulfate, zinc oxide, magnesium sulfate, and monensin. Average feeding costs per day are presented in Table 1. Cow value at the beginning of the study was calculated from the Nebraska average price reported by the USDA Agricultural Marketing Service for the corresponding date and respective average BW. Total breeding
Table 1. Average feedstuff prices for each location $/d per head Description Hay3 Winter pasture Meadow pasture Supplement4 Yardage
GSL1
WCREC2
1.43 — 1.00 0.18 0.30
— 1.00 — 0.08 —
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE): hay and supplement (0.90 kg/d per head) were fed from November to February. In yr 1 the females grazed meadow pastures March and April. In yr 2 hay and supplement were fed until females were sold in April. 2 West Central Research and Extension Center (WCREC, North Platte, NE): heifers grazed winter range and received supplement (0.23 kg/d per head) from November to April. 3 Hay cost assumed as $121/t for yr 1 and $97.21/t for yr 2. 4 Supplement containing approximately 29% CP, DM priced at $424/t. 1
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Rebreeding beef females
Table 2. Average hay and animal prices used in the sensitivity analysis of rebreeding nonpregnant females for market scenarios for the last 5 yr Description Hay ($/t) Cow initial value ($/head) Cull cow ($/head) Pregnant cow ($/head)
cost for GSL females included CIDR (Eazi-Breed CIDR, Zoetis Inc.) cost at $11.25/cow, a single PG injection at $2.87/cow, and labor expense of $5/cow. Breeding cost for the WCREC heifers included CIDR cost at $11.25/heifer, a single PG injection at $2.87/heifer, GnRH injection at $2.68/injection, estrus detection aids at $1.16/patch, semen at $25/dose, and technician expense of $8/cow. Total cost was calculated by adding the purchase price, total feeding cost, breeding expenses, and 6% annual interest rate on the purchase price. The net cost of one pregnant cow was calculated as the difference between total cost and cull value, divided by the number of pregnant cows. Net gain was calculated as the difference between pregnant female price and net cost.
Sensitivity Analysis A sensitivity analysis evaluated the economics of retaining and rebreeding
2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
76.68 929.07 1,055.46 1,749.32
106.98 1,175.50 1,280.63 2,003.20
235.09 1,157.69 1,062.15 1,390.00
121.22 874.97 1,324.05 1,699.25
97.21 1,396.13 1,615.83 2,420.20
strategy for market scenarios for the last 5 yr (2010/2011 to 2014/2015) at different pregnancy rates. An analysis was performed for each location (WCREC and GSL), considering the WCREC heifers were timed AI and the GSL heifers were synchronized and placed with bulls for 60 d. Heifers were considered to be 15 mo old for both locations. Feeding was assumed to be similar for the 2 locations, hay and supplement for a 160-d period. Average hay prices for each year were obtained from the Nebraska average price reported by the USDA Agricultural Marketing Service (2010–2015). Cow and heifer values in November, March, and April were calculated from the Nebraska average price reported by the USDA Agricultural Marketing Service (2010–2015) for the corresponding date and respective average BW. Average hay and animal prices used in the sensitivity analysis are presented in Table 2. Total breeding costs were assumed to be similar
Table 3. Reproductive performance in the rebreeding season Description
GSL1
WCREC2
n AI pregnancy rate (%) Overall pregnancy rate (%) Conceived in the first 21 d (%)
133 — 86.1 84.4
15 53.3 80.0 66.6
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE): cows were synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) on d 0 followed by CIDR removal and prostaglandin F2α (PG; Lutalyse, Zoetis) on d 7 before a 60-d natural service breeding season, 1:25 bull-to-cow ratio. 2 West Central Research and Extension Center (WCREC, North Platte, NE): heifers were synchronized with CIDR and gonadotropin-releasing hormone (Fertagyl, Intervet Inc., Millsboro, DE) on d 0 followed by CIDR removal and PG on d 7 and AI 60 h later. After AI, heifers were placed with bulls for 170 d. 1
each year. Breeding expenses for GSL females included CIDR, a single PG injection, and labor. Breeding cost for the WCREC heifers included CIDR, PG, GnRH, heat detectors, semen, and technician labor.
RESULTS AND DISCUSSION The overall pregnancy rate was 86.1% at GSL and 80.0% at WCREC (Table 3). A high percentage conceived in the first 21 d of the breeding season (84.4 and 66.6% at GSL and WCREC, respectively). Females calving earlier in the calving season will be more adaptable to the fall calving system and be more productive as fall-calving cows (Cushman et al., 2013). The partial budget analysis of rebreeding a female that would be culled is presented in Table 4. The total cost per female was $1,487.62 and $1,703.76 for GSL and WCREC, respectively. Feeding expenses were lower for WCREC heifers because no hay and a minimal amount of supplement were fed. Rebreeding expenses were lower for GSL because the cows and heifers were not AI. An important breeding expense in natural breeding systems is bull cost; nevertheless, it was not included in the breeding expenses in this study because it was assumed the operation already had bulls not in use after the spring breeding season. An alternative approach to calculate the bull cost is to divide the costs for the 2 breeding seasons. In this scenario, the rebreeding season has the additional advantage of increased bull use, reducing the breeding costs of the regular breeding season.
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Table 4. Partial budget analysis of rebreeding a nonpregnant beef female $/beef female Description Initial value (November) (re)Breeding expenses3 Feeding expenses4 Interest (6%) Total cost Cull cow value (March) Net cost Sale value (April) Net gain
GSL1
WCREC2
1,168.89 19.12 270.58 29.03 1,487.62 1,475.45 1,502.71 2,023.00 520.29
1,422.41 57.63 188.16 35.56 1,703.76 1,549.26 1,742.38 2,359.19 616.81
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE; cows and heifers). West Central Research and Extension Center (WCREC, North Platte, NE; heifers). 3 Breeding expenses include for GSL cost of technician, controlled internal drugrelease insert (CIDR; Zoetis, Florham Park, NJ), and prostaglandin F2α (Lutalyse, Zoetis) and for WCREC cost of technician, semen, CIDR, prostaglandin F2α, heat detectors, and gonadotropin-releasing hormone. 4 Feeding expenses for approximately 160 d for GSL yr 1: hay and supplement from November to February and meadow pastures from March to April; for GSL yr 2: hay and supplement from November to February and hay from March to April; and for WCREC (yr 2): winter range and supplement from November to April. 1 2
Another bull-related expense that might increase breeding costs is the necessity of retesting the bulls before the rebreeding season for trichomoniasis. Trichomoniasis is associated with early-term abortions and reduction in revenue because of pregnancy losses (Rae, 1989). The low cost of testing breeding bulls compared with the magnitude of losses this disease can cause suggests that retesting for trichomoniasis may be a prudent decision.
Despite the differences in breeding and feeding costs between the 2 locations, the difference in the total cost between locations is primarily due to initial price. Heifers at WCREC were all 15 mo of age and had higher market price per hundredweight in November compared with older females that made up 20% of the GSL females. The best candidates for this strategy, in fact, are young females, such as
heifers and primiparous cows. Those females have more productive life remaining and the greatest potential for added value when sold later as a pregnant cow compared with its current value as a cull cow. Although younger females have higher risk of being culled due to pregnancy failure with their second and third calves, older cows have less productive life remaining, and it is less likely there would be enough extra value to capture to make the strategy profitable. The remaining nonpregnant females were sold in March, and they had a market price lower than the total cost for both locations (Table 4), adding to the net cost. Thus, as the percentage of nonpregnant cows increases or the value of these animals decreases, the net cost per pregnant female increases. Pregnant cows sold in April increased in value compared with November prices by approximately 73 and 66%, for GSL and WCREC, respectively. The increasing cattle prices from November to April and a greater market price for pregnant females resulted in a net gain of $520.29 and $616.81 per pregnant female for GSL and WCREC, respectively. The higher net gain for WCREC is due to the greater sale price for pregnant heifers compared with older pregnant cows. In addition to the seasonality of the market, the value difference between slaughter and pregnant cows is mainly responsible for making the strategy presented in this study profitable.
Table 5. Sensitivity analysis of rebreeding nonpregnant females for market scenarios for the last 5 yr at different pregnancy rates—GSL Pregnancy rate (%) 10 30 50 70 90
Net proceeds ($/heifer exposed; GSL—NSB)1 2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
−92.16 52.44 197.03 341.62 486.21
−207.67 −55.82 96.02 247.86 399.71
−802.44 −730.17 −657.91 −585.65 −513.38
63.66 147.12 230.59 314.05 397.51
−84.79 85.58 255.95 426.31 596.68
Gudmundsen Sandhills Laboratory (GSL, Whitman, NE) natural service breeding (NSB): synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) on d 0 followed by CIDR removal and prostaglandin F2α (Lutalyse, Zoetis) on d 7 before a 60-d NSB season, 1:25 bull-to-cow ratio. Feeding was considered to be hay and supplement for a 160-d period.
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Table 6. Sensitivity analysis of rebreeding nonpregnant females for market scenarios for the last 5 yr at different pregnancy rates—WCREC Pregnancy rate (%) 10 30 50 70 90
Net proceeds ($/heifer exposed; WCREC—TAI)1 2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
−91.01 35.56 162.14 288.72 415.29
−206.05 −76.86 52.34 181.54 310.73
−860.31 −808.62 −756.94 −705.26 −653.57
92.52 150.11 207.69 265.27 322.86
−57.27 83.81 224.89 365.97 507.05
West Central Research and Extension Center (WCREC, North Platte, NE) fixed-time AI (TAI): synchronized with a controlled internal drug-release insert (CIDR; Zoetis, Florham Park, NJ) and gonadotropin-releasing hormone (Fertagyl, Intervet Inc., Millsboro, DE) on d 0 followed by CIDR removal and prostaglandin F2α (Lutalyse, Zoetis) on d 7 before TAI. After TAI 60 h later, heifers were placed with bulls for approximately 170 d. Feeding was considered to be hay and supplement for a 160-d period.
1
The data presented in Table 4 indicate that delayed selling of cull cows is not a highly profitable strategy. If, instead of rebreeding the nonpregnant spring-calving cows, we had simply retained to sell as slaughter cows in March, we would have a $6.95/head profit for GSL and $96.87/head loss for WCREC. Despite the seasonal behavior of the market, with high prices in March and April and lows from September to November, the costs for feeding during this period can equalize or even overcome greater cow prices. Small operations, depending on the number of cull cows, may find that the extra labor and expense of keeping them throughout the winter may outweigh the benefit. The sensitivity analysis is presented in Tables 5 and 6 for GSL and WCREC, respectively. Considering feeding costs the same for both locations and considering all animals as 15-mo heifers, GSL had the greatest return. However, when available, less expensive feeding strategies should be considered to improve economic return. Because of additional costs with AI, the natural service breeding had reduced breeding costs, increasing the net proceeds per heifer exposed at a given pregnancy rate. In the present study all females were sold at livestock auction, and AI pregnant
females were not valued differently than females pregnant by natural service. Furthermore, the USDA Agricultural Marketing Service does not provide alternative prices for females pregnant via AI or natural service. If higher market prices exist for AI pregnant heifers and cows and exceed the increased AI costs, it is recommended to use AI to increase profits. The rebreeding strategy was not cost effective in the 2012/2013 scenario. As a result of the 2012 drought, feedstuff prices in 2012 were greatest and market prices lowest; consequently, production costs were greater than gross proceeds. As a result, in 2012/2013 this management practice was not profitable, regardless of pregnancy rate. With the exception of 2012/2013, the strategy appears to be cost effective even at a modest pregnancy rate. However, as pregnancy rate increases, net proceeds increase.
IMPLICATIONS In the present study, satisfactory reproductive and economic performances were achieved by retaining nonpregnant females and rebreeding for a fall calving season. The strategy provides an alternative to potentially increase financial returns with cull beef females.
LITERATURE CITED Cushman, R. A., L. K. Kill, R. N. Funston, E. M. Mousel, and G. A. Perry. 2013. Heifer calving date positively influences calf weaning weights through six parturitions. J. Anim. Sci. 91:4486–4491. Funston, R. N., J. A. Paterson, K. E. Williams, and A. J. Roberts. 2003. Effect of body condition, initial weight and implant on feedlot and carcass characteristics of cull cows. Prof. Anim. Sci. 19:233–238. Melton, E. B. 1980. Economics of beef cow culling and replacement decisions under genetic progress. West. J. Agric. Econ. 5:137–147. Rae, D. O. 1989. Impact of trichomoniasis on the cow-calf producer’s profitability. J. Am. Vet. Med. Assoc. 194:771–775. Roberts, A. J., M. K. Petersen, and R. N. Funston. 2015. Beef Species Symposium: Can we build the cowherd by increasing longevity of females? J. Anim. Sci. 93:4235–4243. http://dx.doi.org/10.2527/jas.2014-8811. Sawyer, J. E., C. P. Mathis, and B. Davis. 2004. Effects of feeding strategy and age on live animal performance, carcass characteristics, and economics of short-term feeding programs for culled beef cows. J. Anim. Sci. 82:3646–3653. Tonsor, G. T., and L. L. Schulz. 2015. Beef Species Symposium: Economic considerations related to U.S. beef herd expansion. J. Anim. Sci. 93:4227–4234. http://dx.doi.org/10.2527/ jas.2014-8473. USDA Agricultural Marketing Service. 2010–2015. Nebraska Livestock Custom Report. https://marketnews.usda.gov/mnp/ ls-report-config.