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Effect of Hay Feeding Methods on Cow Performance, Hay Waste, and Wintering Cost
The Professional Animal Scientist 23 (2007):246–252
Effect of Hay Feeding Methods on Cow Performance, Hay Waste, and Wintering Cost D. G. Landblom,*1 G. P. Lardy,† R. Fast,‡ C. J. Wachenheim,§ and T. A. Petry¶ *Dickinson Research Extension Center, North Dakota State University, Dickinson 58601; †Animal and Range Sciences Department, North Dakota State University, Fargo 58105; ‡Agriculture and Technical Studies Department, Dickinson State University, Dickinson 58601; §Agribusiness and Applied Economics Department, North Dakota State University, Fargo 58105; and ¶Extension Agricultural Economics, North Dakota State University, Fargo 58105
ABSTRACT A 3-yr investigation was conducted to determine the effect of hay feeding methods on cow wintering cost. A conventional method of rolling round bales out on the ground was compared with shredding round hay bales on the ground with a bale processor and with feeding hay in a tapered-cone round bale feeder. The cows used in the study were in the third trimester of pregnancy and were fed for an average of 59 d during the test period. Data recorded from the multipleyear study was then used to prepare an economic analysis model with operating budgets for 100- and 300-head reference herds. Feeding bales in a tapered-cone round bale feeder increased cow weight gain (P < 0.01), tended to increase rib fat depth (P = 0.06), reduced estimated hay consumption by an average of 10.2% compared with rolling bales out on the ground or using a bale processor to shred hay on the ground (P < 0.01), and reduced hay waste in the first 2 yr of the study when alfalfa-grass hay was fed, but not in the last year when oat hay was fed. The tapered-cone round
1
Corresponding author: douglas. [email protected]
bale feeder reduced waste, decreased the amount of hay required per cow, and decreased wintering cost per cow while maintaining body condition. Overall, for the 3 yr evaluation period, using the tapered-cone round bale feeder reduced wintering cost by 21.0% for a 100-cow reference herd and 17.6% for a 300-cow reference herd compared with feeding with a bale processor. Key words: beef cow, feeding method, hay, wintering cost
INTRODUCTION Winter feed cost makes up a large portion of production costs for North Dakota beef cattle producers and is the single largest variable influencing profitability (Miller et al., 2001). Over the last 5 yr, winter feed costs averaged $144 per head for producers participating in North Dakota’s Farm and Ranch Business Management Program (Swenson, 2006). The most common method for putting up hay in North Dakota is the large round bale, and rolling round bales out on the ground has been the most common method of feeding hay (Figure 1). However, power takeoff (PTO)-driven bale processors are becoming popular as reducing labor
becomes more important (Figure 2). A number of different bale feeders are commercially available. Recently, a tapered-cone round bale feeder has also been introduced (Figure 3). Previous reports suggest that feeder type and animal behavior can influence the amount of hay wasted by beef cattle. Buskirk et al. (2003) reported losses with various feeder types of 3.5% (tapered-cone), 6.1% (ring), 11.4% (trailer), and 14.6% (cradle feeder). Depending on storage method, forage storage time, forage type, and environmental conditions, forage DM losses can range from 2 to 18% (Belyea et al., 1985; Baxter et al., 1986; Huhnke, 1987). Hay processors have gained acceptance because they are reported to reduce overall investment in machinery compared with tub grinding and feeding hay with a mixer wagon. Although bale processing machines do not have mixing capabilities, they can be used effectively for filling bunks or for feeding on the ground, especially with ‘stemmy’ hays, because the stems are chopped and essentially mixed in the windrow as the cattle are fed, effectively eliminating or reducing sorting problems. Bale processors are also associated with considerable dust when forage is being processed.
Performance of Cow Hay Feeding Methods
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consumption necessary to maintain cow body condition, labor inputs, wintering cost, and hay waste when hay was either rolled out on the ground, shredded with a bale processor on the ground, or fed in a tapered-cone round bale feeder.
MATERIALS AND METHODS
Figure 1. Round bale roll out - the conventional hay feeding method in which round bales were rolled out on the ground.
Considering the 3 methods available for feeding hay during the win-
ter, this study was designed to compare cow wintering performance, hay
Figure 2. Power take-off (PTO)-driven round bale processor — feeding shredded hay from round bales using a PTO-driven round bale hay processor.
Three hundred sixty crossbred cows averaging 610 kg (n = 144 during yr 1 and n = 108 in both yr 2 and 3) were assigned randomly to one of twelve 2.02 ha wintering lots located at the Dickinson Research Extension Center (Dickinson, ND). There were 4 pen replicates per treatment. Treatments were as follows: 1) conventional method — round bales fed by rolling bales out on the ground, 2) round bales shredded with a PTOdriven bale processor and fed on the ground, and 3) round bales fed by placing the bale in a taperedcone round bale feeder. The investigation was conducted during North Dakota’s coldest months of January and February each year. The mean 24-h ambient temperature for January and February, during the period between 2000 and 2004, was −8.4°C and −8.9°C for January and February, respectively. Cows were weighed, visually scored for BCS, and measured for rib fat depth using real-time ultrasound at the beginning, middle, and end of the 59-d study. Starting and ending weights were the average of 2 consecutive daily weights, and the midweight was taken before feeding on the appointed day. The BCS was a subjective numeric evaluation of fatness obtained using a 1 to 9 scoring system where “1” is extremely thin and “9” is extremely fat (Eversole et al., 2000). Subcutaneous fat depth measurements were taken using a SonoVet2000 ultrasound instrument (Universal Medical Systems, Bedford Hills, New York) equipped with a 3.5 MHz transducer (17.2 cm
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Figure 3. Tapered cone round bale feeder — feeding long hay with the tapered-cone round bale feeder.
length). Before the cross-sectional ribeye images were captured, an 8 × 20 cm area of hair, located over the longissimus dorsi muscle and the space between the 12th and 13th ribs, was clipped to ≤ 5 mm, curry combed to remove loose hair and debris, and a liberal amount of vegetable oil was applied to the skin as an air-excluding couplant. With the ultrasound probe placed over the longissimus dorsi muscle oriented in alignment with the anatomical separation between the 12th and 13th ribs, subcutaneous fat measurements were taken at a point three-fourths of the width of the cross-sectional ribeye image as prescribed by the Ultrasound Guidelines Council (UGC, 2007) for live animal evaluation. Quantity and quality of hay offered and feeding time for each system was recorded. Individual bales were weighed and core sampled for subsequent nutrient analysis. For yr 1 and 2 of the study, alfalfabromegrass-crested wheatgrass hay was offered; however, during the
third yr of the study, oat hay was offered. Chemical analysis for the forage offered each year, as determined with wet chemistry, is shown in Table 1. For DMI prediction (NRC, 1996), the NEm of the mixed hay fed was estimated at approximately 1.146 Mcal/kg (1.07, 1.14, and 1.31 Mcal/kg for crested wheatgrass, bromegrass, and alfalfa hay, respectively). Based on the current DMI prediction equation for second and third trimester beef cows (NRC, 1996), initial DMI was estimated according to the following formula: DMI = (SBW0.75 × (0.04997 × NEm2 + 0.04361)/ NEm)
[1]
where SBW0.75 is shrunk body weight (weight, kg × 0.95) to the 0.75 power, and NEm is expressed in Mcal/kg. The DMI value was further adjusted weekly for temperature fluctuations as follows: ≥ −12.2°C, no adjustment; −12.2 to −15.0°C, DMI was increased 7%; −15.0 to −17.8°C, DMI was in-
creased 10%; and when temperatures declined to a range between −17.8 and −23.3°C, DMI was increased 16%. Based on cow progeny growth performance, cow lactation ability was estimated to be ≥ 9.1kg of daily milk; therefore, DM offered was increased 1.10kg/d. An adjustment for mud was not required given the temperature ranges previously described for January and February. Calculation of initial DMI, using the current NRC (1996) prediction formula, served as the reference point for hay offered; however, changes in BCS and ultrasound fat depth that occurred between the initial measurement and trial midpoint measurement were used to determine the adequacy of the amount of hay offered. When the difference between initial and midpoint ultrasound fat depth change declined, the amount of hay offered to the rollout and bale processor groups was increased 10.2 and 15.1%, respectively, to maintain similar BCS and fat depth across treatments. Hay waste was measured to account for the decline in BCS by securing two 1.016 × 2.032 m carpets to the ground, and daily hay offerings were fed over the carpets for 3 consecutive d in each of the 4 pen replicates per feeding method treatment. The carpets were cleaned 24 h after feeding, and the residual forage and fines were collected, dried (60°C for 72 h), weighed, and analyzed for nutrient content using wet chemistry. Fecal contamination of residual forage could be considered a problem; however, very few fecal droppings were found on the carpet sample areas and the droppings that were found on the carpet samples were frozen and easily discarded. Care was taken to insure that any forage pieces attached to the frozen droppings were removed and retained with the sample collected. Area of waste was not measured the first year of the study. The second year,
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Table 1. Forage analysis Feeding method
Yr 1: Alfalfa-bromegrass-crested wheatgrass hay DM, % Ash, % CP, % ADF, % NDF, % Calcium, % Phosphorus, % IVOMD,2 % Yr 2: Alfalfa-bromegrass-crested wheatgrass hay DM, % Ash, % CP, % ADF, % NDF, % IVOMD, % Yr 3: Oat hay DM, % Ash, % CP, % ADF, % NDF, % IVOMD, %
Round bale roll out
PTO1-driven round bale processor
Tapered-cone round bale feeder
P value
95.2 −9.0 14.6 38.9a 53.9 1.1 0.23 58.1
94.9 9.2 14.4 39.3a 54.6 1.0 0.22 56.2
95.1 8.9 14.6 40.7b 53.1 1.0 0.22 56.7
0.47 0.12 0.87 0.008 0.81 0.92 0.80 0.20
95.9c 7.9b 9.6b 39.3 60.7 59.1
96.8a 8.5a 12.1a 39.6 60.2 57.4
96.1b 7.4c 9.7b 41.0 61.5 58.9
<0.01 0.05 0.08 0.42 0.70 0.64
88.9 9.1b 12.8a 39.2 70.5 60.7b
89.5 9.8a 12.9a 39.7 72.9 63.2a
88.2 9.6a 13.4b 39.2 70.9 60.4b
0.17 <0.01 0.02 0.83 0.10 <0.01
Means within a row with different superscripts differ (P < 0.10). PTO = power take-off. 2 IVOMD = dietary in vitro OM disappearance. a–c 1
area of hay waste was estimated manually by taping the length and width in several locations, and the third year the area of waste was measured using GPS spatial mapping. Using an Ag-132 Trimble Receiver (Trimble Navigation Ltd., Sunnyvale, CA), the feeding area of waste perimeter was walked. Geolink software (Michael Baker Corp., Moon Township, PA), an interface between the Trimble receiver and Arcview software (Environmental Systems Research Institute Inc., Redlands, CA), created a polyline, which was processed by Arcview into a polygon. Arcview and the Fujitsu monitor (CDW Corp., Vernon Hills, IL) were then used to calculate the area of the polygon. Cow growth, BCS, hay intake, fat depth, and waste data were ana-
lyzed as a complete randomized design with the GLM procedure of SAS (SAS Inst., Inc., Cary, NC) using pen as the experimental unit. The model included treatment and year and the 2-way interaction between treatment and year. When an interaction was not significant, the data was combined and reanalyzed. Differences were considered significant when P < 0.05, tendencies when 0.05 < P < 0.10, and nonsignificant when P > 0.10.
Economic Analysis of Winter Feeding Methods Production measurements and efficiency, time required for feeding, equipment and machinery inputs, and depreciation were used to develop an economic analysis model
to compare the 3 feeding methods using both 100- and 300-head reference herds in the model. The 2 herd sizes in the model represent the 2 most common cow herd sizes in North Dakota (North Dakota Agricultural Statistics, 2005). The model assumed a winter feeding period of 135 d and hay priced at $42.50/ton. The tapered-cone round bale feeders were valued at $800 each and assumed to feed 13 to 15 cows. The round bale processor was priced at $15,000. It was assumed that bale processor cutting flails would be replaced every 2,500 bales at a charge of $250, including labor. Tractor expenses were based on a 110-horsepower unit in all treatments, and allocation was based on typical use in other farm activities, of which win-
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Table 2. Three-year effect of hay feeding method on cow performance and hay intake Feeding method Round bale roll out Cow performance Cows, n Days fed Initial BW, kg Final BW, kg BW gain, kg ADG, kg Hay/cow, kg Yr 1 Yr 2 Yr 3 Hay/cow per day, kg Yr 1 Yr 2 Yr 3 BCS3 Initial Final BCS change Rib fat depth change, mm Yr 1 Yr 2 Yr 3
120 59 616.7 639.2 22.5a 0.381a 815a 1021a 917a 14.0a 18.6a 14.3a
PTO1-driven round bale processor 120 59 614.0 643.9 29.9b 0.507b 799b 1,067b 1,022b 13.6a 19.4b 16.0b
5.88 5.83 −0.04 −0.80a 1.32a −0.72a
5.77 5.80 0.029 −0.53b 1.18a −1.42b
P value Tapered-cone round bale feeder
SE
Yr
Trt
Yr × Trt
120 59 618.9 655.0 36.1b 0.611b
— — 11.75 10.83 2.72 0.046
— — 0.18 0.07 0.46 0.40
— — 0.96 0.58 <0.01 <0.01
— — 0.99 0.96 0.16 0.144
14.21 — —
<0.01 — —
<0.01 — —
0.004 — —
0.21 — —
<0.01 — —
<0.01 — —
0.0003 — —
5.94 6.01 0.07
0.087 0.083 0.081
<0.01 <0.01 <0.01
0.38 0.15 0.60
0.63 0.10 0.22
0.30c 2.22b −1.02c
0.38 — —
<0.01 — —
0.06 — —
0.39 — —
692c 925c 878c 11.9b 16.8c 13.7c
Values with unlike superscripts differ significantly (P < 0.05). PTO = power take-off. 2 Trt = treatment. 3 1 to 9 scale (1 = extremely thin; 9 = obese). a–c 1
ter feeding is one (Lazarus and Selley, 2002). Operation and ownership costs were $27/h, including a $7/h labor charge. Based on feeding time measured for each feeding method, the tractor time allocation
for filling the round bale feeders was calculated to be 3 min/bale and 5 min/bale for the bales either rolled out on the ground or shredded with the PTO-driven bale processor.
RESULTS AND DISCUSSION Cows were fed to maintain or improve their starting body condition prior to calving. Chemical analysis of the forages offered during the 3-
Table 3. Quantitative estimate of feeding area waste for each hay feeding method Feeding method Item Alfalfa-grass hay, kg Oat hay, kg 1 2
PTO = power take-off. Trt = treatment.
P value
Round bale roll out
PTO1-driven round bale processor
Tapered-cone round bale feeder
SE
Yr
Trt2
Yr × Trt
61.5 48.4
52.5 28.1
12.1 90.3
9.72 —
0.09 —
0.30 —
<0.01 —
Performance of Cow Hay Feeding Methods
Table 4. Three-year economic analysis comparing hay feeding methods for 100- and 300-head cow herds Feeding method
Item Hay consumed/d, kg Hay fed, metric tons2 100-cow herd 300-cow herd Hay cost/cow, $ Total hay cost, $ 100-cow herd 300-cow herd Equipment costs,3 $ 100-cow herd, per cow 300-cow herd, per cow Per 100-cow herd Per 300-cow herd Tractor operation costs,4 $ Cost per cow Per 100-cow herd Per 300-cow herd Total nonhay expense, $ Per cow, 100-cow herd Per cow, 300-cow herd Per 100-cow herd Per 300-cow herd Total expense, $ Per 100-cow herd Per 300-cow herd Total cost per cow, $ 100-cow herd 300-cow herd Hay cost, as % of total cost 100-cow herd 300-cow herd
Round bale roll out
PTO1-driven round bale processor
Tapered-cone round bale feeder
15.6
16.3
14.2
210.5 632.2 98.58
220.5 660.3 103.11
190.9 572.8 89.45
9,858 29,574
10,311 30,934
8,945 26,834
— — — —
12.98 7.62 $1,298 $2,288
5.13 5.13 $513 1,538
10.44 1,044 3,131
10.92 1,092 3,275
5.68 568 1,705
10.44 10.44 1,044 3,131
23.90 18.55 2,390 5,564
10.81 10.81 1,081 3,243
10,902 32,705
12,701 36,497
10,026 30,077
109.0 109.0
127.0 121.7
100.3 100.3
90.4 90.4
81.2 84.8
89.2 89.2
1
PTO = power take-off. Metric tons of hay fed over a 135-d period. Hay was priced at $42.50/ton. 3 Each bale feeder cost $800 and fed 13 cows in the analysis model. Bale feeders were depreciated over 12 yr. The bale processor cost $15,000. It was depreciated over 12 yr for the 100-cow operation and 7 yr for the 300-cow operation. Cutting flails were replaced every 2,500 bales at a total replacement cost of $250 including labor charge. 4 A 110-HP tractor was used regardless of system; model expense referenced from Lazarus and Selley (2002). Ownership expenses calculated assuming the tractor experienced typical use in other farm operation activities. Operation and ownership costs are $27/h including a $7/h labor charge. Tractor time is 3 min per bale for the bale feeder and 5 min per bale for roll out and bale processor systems. 2
yr investigation is shown in Table 1. Statistically, no year × treatment interactions for growth and BCS were identified; therefore, data for
the 3-yr study was pooled (Table 2). Cows fed using the conventional method in which bales are rolled out on the ground gained less (P <
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0.01) than when cows were fed with either the bale processor or tapered-cone round bale feeder. Starting, ending, and BCS change differed between years, but there were no differences due to treatment (P = 0.15). In addition to the subjective BCS, ultrasound fat depth measurements were used to quantify body condition change associated with each feeding method. Significant variation was measured between years (P < 0.01) and there was a tendency for increased fat depth within year (P = 0.06). During the first 2 yr of the study, cows fed using the tapered-cone round bale feeder had greater rib fat depth increase than either the roll out or bale processor methods. During the third year of the study, rib fat depth change declined from the start to the end of the test feeding period, but the magnitude of the decline did not differ between feeding methods. Cows used during the third year were in better overall body condition at the start of the test feeding period, which may have contributed to the observed condition decline. The decline suggests that the level of energy supplied to all cow groups was not sufficient to maintain the initial BCS. Hay offered to maintain BCS was greatest for cows fed with the bale processor, intermediate when bales were rolled out, and the least when cows were fed using a tapered-cone round bale feeder (P < 0.01). On average, when compared with the tapered-cone round bale feeder, 5.0 and 15.3% more hay was offered per cow using the roll out and bale processor methods, respectively. Waste contributed to the increased amount of hay required among the roll out and bale processor cow groups (Table 3). An estimate of waste suggested that type of hay and firmness of bales played a significant role in success with the tapered-cone round bale feeder. When dense alfalfa-grass hay bales were tied tightly and strings were not removed for feeding, waste
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around the tapered-cone round bale feeder was 4.3 to 5.0 times less than either the roll out or bale processor methods, respectively. However, when loose, poorly tied oat hay bales were fed in the tapered-cone round bale feeder, waste was numerically decreased but did not differ with the bale processor (P = 0.30). Bale processors are used for all sorts of hay whether coarse or fine textured and shred the forage as it is being discharged from the machine, reducing particle size. Shredding with the bale processor is associated with considerable dust (wasted feed) and fine particles that, when fed on the ground, are difficult for cattle to pick without eating dirt as well. Our research team observed that for maximum effectiveness when using a bale processor to shred hay, a bale processor would be best suited to deliver hay into bunks. However, our study did not evaluate offering shredded hay in bunks as one of the treatments. Over the 3-yr period, these data suggest that hay waste is minimal with the taperedcone round bale feeder when bales are dense, adequately tied, and strings are not removed prior to feeding. Economic model analysis suggests that feeding with a tapered-cone round bale feeder offers substantial cost savings per cow arising from a reduction in the amount of hay offered, equipment cost, and feeding time. Wintering cost per cow for the 100-cow reference herd was $109, $127, and $100 for rolling out bales, shredding with a bale processor, and feeding bales in a ta-
Landblom et al.
pered-cone round bale feeder, respectively (Table 4). The per-cow cost using a 300-cow reference herd was $122 compared with $127 for the 100-cow reference herd fed with the processor due to differences in the rate of depreciation between the 2 herd sizes in the economic model. Using a bale processor to shred bales into windrows before feeding was the most expensive due to greater equipment ownership cost and greater hay intake per cow necessary to maintain a comparable condition compared with the tapered-cone round bale feeder. Rolling bales out and shredding into windrows with a bale processor increased hay consumption and winter feed cost.
IMPLICATIONS Using dense, properly tied bales, the tapered-cone round bale feeder was a superior winter hay feeding method when compared with either rolling bales out on the ground or shredding on the ground with a bale processor. Tapered-cone round bale feeders reduced waste, decreased the amount of hay required per cow from 5.0 to 15.3%, and decreased wintering cost per cow while maintaining body condition. Economic analysis for the 3 wintering seasons identified an economic advantage for using the tapered-cone round bale feeding method.
ACKNOWLEDGMENTS Partial funding for this project was provided by the North Dakota
Beefline Initiative, North Dakota State University, Agricultural Experiment Station.
LITERATURE CITED Baxter, H. D., B. L. Bledsoe, M. J. Montgomery, and J. R. Owen. 1986. Comparison of alfalfa-orchardgrass hay stored in large round bales and conventional rectangular bales for lactating cows. J. Dairy Sci. 69:1854. Belyea, R. L., F. A. Martz, and S. Bell. 1985. Storage and feeding losses of large round bales. J. Dairy Sci. 68:3371. Buskirk, D. D., A. J. Zanella, T. M. Harrigan, J. L. Van Lente, L. M. Gnagey, and M. J. Kaercher. 2003. Large round bale feeder design affects hay utilization and beef cow behavior. J. Anim. Sci. 81:109. Eversole, D. E., M. R. Browne, J. B. Hall, and R. E. Dietz. 2000. Body Condition Scoring Beef Cows. Virginia State University Cooperative Extension Service Publication. http:// www.ext.vt.edu/pubs/beef/400-795/400795.html Accessed April 2007. Huhnke, R. L. 1987. Large round bale alfalfa storage. Appl. Eng. Agric. 4:316. Lazarus, W., and R. Selley. 2002. Farm Machinery Economic Cost Estimate for 2002. Univ. Minnesota Ext. Serv., St. Paul. Miller, A. J., D. B. Faulkner, R. K. Knipe, D. R. Strohben, D. F. Parrett, and L. L. Berger. 2001. Critical control points for profitability in the cow-calf enterprise. Prod. Anim. Sci. 17:295. National Research Council. 1996. Nutrient Requirements of Beef Cattle. 7th rev. ed. Natl. Acad. Press, Washington, DC. North Dakota Agricultural Statistics. 2005. North Dakota Agric. Statistics Serv. Bull. No. 74:83. Fargo, ND. Swenson, A. 2006. North Dakota Farm and Ranch Business Management Annual Rep. North Dakota State Univ. Ext. Serv., Fargo. Ultrasound Guidelines Council. 2007. Iowa Falls, IA. www.aptcbeef.org/site/298/default.aspx Accessed April 2007.
Effect of Hay Feeding Methods on Cow Performance, Hay Waste, and Wintering Cost D. G. Landblom,*1 G. P. Lardy,† R. Fast,‡ C. J. Wachenheim,§ and T. A. Petry¶ *Dickinson Research Extension Center, North Dakota State University, Dickinson 58601; †Animal and Range Sciences Department, North Dakota State University, Fargo 58105; ‡Agriculture and Technical Studies Department, Dickinson State University, Dickinson 58601; §Agribusiness and Applied Economics Department, North Dakota State University, Fargo 58105; and ¶Extension Agricultural Economics, North Dakota State University, Fargo 58105
ABSTRACT A 3-yr investigation was conducted to determine the effect of hay feeding methods on cow wintering cost. A conventional method of rolling round bales out on the ground was compared with shredding round hay bales on the ground with a bale processor and with feeding hay in a tapered-cone round bale feeder. The cows used in the study were in the third trimester of pregnancy and were fed for an average of 59 d during the test period. Data recorded from the multipleyear study was then used to prepare an economic analysis model with operating budgets for 100- and 300-head reference herds. Feeding bales in a tapered-cone round bale feeder increased cow weight gain (P < 0.01), tended to increase rib fat depth (P = 0.06), reduced estimated hay consumption by an average of 10.2% compared with rolling bales out on the ground or using a bale processor to shred hay on the ground (P < 0.01), and reduced hay waste in the first 2 yr of the study when alfalfa-grass hay was fed, but not in the last year when oat hay was fed. The tapered-cone round
1
Corresponding author: douglas. [email protected]
bale feeder reduced waste, decreased the amount of hay required per cow, and decreased wintering cost per cow while maintaining body condition. Overall, for the 3 yr evaluation period, using the tapered-cone round bale feeder reduced wintering cost by 21.0% for a 100-cow reference herd and 17.6% for a 300-cow reference herd compared with feeding with a bale processor. Key words: beef cow, feeding method, hay, wintering cost
INTRODUCTION Winter feed cost makes up a large portion of production costs for North Dakota beef cattle producers and is the single largest variable influencing profitability (Miller et al., 2001). Over the last 5 yr, winter feed costs averaged $144 per head for producers participating in North Dakota’s Farm and Ranch Business Management Program (Swenson, 2006). The most common method for putting up hay in North Dakota is the large round bale, and rolling round bales out on the ground has been the most common method of feeding hay (Figure 1). However, power takeoff (PTO)-driven bale processors are becoming popular as reducing labor
becomes more important (Figure 2). A number of different bale feeders are commercially available. Recently, a tapered-cone round bale feeder has also been introduced (Figure 3). Previous reports suggest that feeder type and animal behavior can influence the amount of hay wasted by beef cattle. Buskirk et al. (2003) reported losses with various feeder types of 3.5% (tapered-cone), 6.1% (ring), 11.4% (trailer), and 14.6% (cradle feeder). Depending on storage method, forage storage time, forage type, and environmental conditions, forage DM losses can range from 2 to 18% (Belyea et al., 1985; Baxter et al., 1986; Huhnke, 1987). Hay processors have gained acceptance because they are reported to reduce overall investment in machinery compared with tub grinding and feeding hay with a mixer wagon. Although bale processing machines do not have mixing capabilities, they can be used effectively for filling bunks or for feeding on the ground, especially with ‘stemmy’ hays, because the stems are chopped and essentially mixed in the windrow as the cattle are fed, effectively eliminating or reducing sorting problems. Bale processors are also associated with considerable dust when forage is being processed.
Performance of Cow Hay Feeding Methods
247
consumption necessary to maintain cow body condition, labor inputs, wintering cost, and hay waste when hay was either rolled out on the ground, shredded with a bale processor on the ground, or fed in a tapered-cone round bale feeder.
MATERIALS AND METHODS
Figure 1. Round bale roll out - the conventional hay feeding method in which round bales were rolled out on the ground.
Considering the 3 methods available for feeding hay during the win-
ter, this study was designed to compare cow wintering performance, hay
Figure 2. Power take-off (PTO)-driven round bale processor — feeding shredded hay from round bales using a PTO-driven round bale hay processor.
Three hundred sixty crossbred cows averaging 610 kg (n = 144 during yr 1 and n = 108 in both yr 2 and 3) were assigned randomly to one of twelve 2.02 ha wintering lots located at the Dickinson Research Extension Center (Dickinson, ND). There were 4 pen replicates per treatment. Treatments were as follows: 1) conventional method — round bales fed by rolling bales out on the ground, 2) round bales shredded with a PTOdriven bale processor and fed on the ground, and 3) round bales fed by placing the bale in a taperedcone round bale feeder. The investigation was conducted during North Dakota’s coldest months of January and February each year. The mean 24-h ambient temperature for January and February, during the period between 2000 and 2004, was −8.4°C and −8.9°C for January and February, respectively. Cows were weighed, visually scored for BCS, and measured for rib fat depth using real-time ultrasound at the beginning, middle, and end of the 59-d study. Starting and ending weights were the average of 2 consecutive daily weights, and the midweight was taken before feeding on the appointed day. The BCS was a subjective numeric evaluation of fatness obtained using a 1 to 9 scoring system where “1” is extremely thin and “9” is extremely fat (Eversole et al., 2000). Subcutaneous fat depth measurements were taken using a SonoVet2000 ultrasound instrument (Universal Medical Systems, Bedford Hills, New York) equipped with a 3.5 MHz transducer (17.2 cm
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Figure 3. Tapered cone round bale feeder — feeding long hay with the tapered-cone round bale feeder.
length). Before the cross-sectional ribeye images were captured, an 8 × 20 cm area of hair, located over the longissimus dorsi muscle and the space between the 12th and 13th ribs, was clipped to ≤ 5 mm, curry combed to remove loose hair and debris, and a liberal amount of vegetable oil was applied to the skin as an air-excluding couplant. With the ultrasound probe placed over the longissimus dorsi muscle oriented in alignment with the anatomical separation between the 12th and 13th ribs, subcutaneous fat measurements were taken at a point three-fourths of the width of the cross-sectional ribeye image as prescribed by the Ultrasound Guidelines Council (UGC, 2007) for live animal evaluation. Quantity and quality of hay offered and feeding time for each system was recorded. Individual bales were weighed and core sampled for subsequent nutrient analysis. For yr 1 and 2 of the study, alfalfabromegrass-crested wheatgrass hay was offered; however, during the
third yr of the study, oat hay was offered. Chemical analysis for the forage offered each year, as determined with wet chemistry, is shown in Table 1. For DMI prediction (NRC, 1996), the NEm of the mixed hay fed was estimated at approximately 1.146 Mcal/kg (1.07, 1.14, and 1.31 Mcal/kg for crested wheatgrass, bromegrass, and alfalfa hay, respectively). Based on the current DMI prediction equation for second and third trimester beef cows (NRC, 1996), initial DMI was estimated according to the following formula: DMI = (SBW0.75 × (0.04997 × NEm2 + 0.04361)/ NEm)
[1]
where SBW0.75 is shrunk body weight (weight, kg × 0.95) to the 0.75 power, and NEm is expressed in Mcal/kg. The DMI value was further adjusted weekly for temperature fluctuations as follows: ≥ −12.2°C, no adjustment; −12.2 to −15.0°C, DMI was increased 7%; −15.0 to −17.8°C, DMI was in-
creased 10%; and when temperatures declined to a range between −17.8 and −23.3°C, DMI was increased 16%. Based on cow progeny growth performance, cow lactation ability was estimated to be ≥ 9.1kg of daily milk; therefore, DM offered was increased 1.10kg/d. An adjustment for mud was not required given the temperature ranges previously described for January and February. Calculation of initial DMI, using the current NRC (1996) prediction formula, served as the reference point for hay offered; however, changes in BCS and ultrasound fat depth that occurred between the initial measurement and trial midpoint measurement were used to determine the adequacy of the amount of hay offered. When the difference between initial and midpoint ultrasound fat depth change declined, the amount of hay offered to the rollout and bale processor groups was increased 10.2 and 15.1%, respectively, to maintain similar BCS and fat depth across treatments. Hay waste was measured to account for the decline in BCS by securing two 1.016 × 2.032 m carpets to the ground, and daily hay offerings were fed over the carpets for 3 consecutive d in each of the 4 pen replicates per feeding method treatment. The carpets were cleaned 24 h after feeding, and the residual forage and fines were collected, dried (60°C for 72 h), weighed, and analyzed for nutrient content using wet chemistry. Fecal contamination of residual forage could be considered a problem; however, very few fecal droppings were found on the carpet sample areas and the droppings that were found on the carpet samples were frozen and easily discarded. Care was taken to insure that any forage pieces attached to the frozen droppings were removed and retained with the sample collected. Area of waste was not measured the first year of the study. The second year,
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Performance of Cow Hay Feeding Methods
Table 1. Forage analysis Feeding method
Yr 1: Alfalfa-bromegrass-crested wheatgrass hay DM, % Ash, % CP, % ADF, % NDF, % Calcium, % Phosphorus, % IVOMD,2 % Yr 2: Alfalfa-bromegrass-crested wheatgrass hay DM, % Ash, % CP, % ADF, % NDF, % IVOMD, % Yr 3: Oat hay DM, % Ash, % CP, % ADF, % NDF, % IVOMD, %
Round bale roll out
PTO1-driven round bale processor
Tapered-cone round bale feeder
P value
95.2 −9.0 14.6 38.9a 53.9 1.1 0.23 58.1
94.9 9.2 14.4 39.3a 54.6 1.0 0.22 56.2
95.1 8.9 14.6 40.7b 53.1 1.0 0.22 56.7
0.47 0.12 0.87 0.008 0.81 0.92 0.80 0.20
95.9c 7.9b 9.6b 39.3 60.7 59.1
96.8a 8.5a 12.1a 39.6 60.2 57.4
96.1b 7.4c 9.7b 41.0 61.5 58.9
<0.01 0.05 0.08 0.42 0.70 0.64
88.9 9.1b 12.8a 39.2 70.5 60.7b
89.5 9.8a 12.9a 39.7 72.9 63.2a
88.2 9.6a 13.4b 39.2 70.9 60.4b
0.17 <0.01 0.02 0.83 0.10 <0.01
Means within a row with different superscripts differ (P < 0.10). PTO = power take-off. 2 IVOMD = dietary in vitro OM disappearance. a–c 1
area of hay waste was estimated manually by taping the length and width in several locations, and the third year the area of waste was measured using GPS spatial mapping. Using an Ag-132 Trimble Receiver (Trimble Navigation Ltd., Sunnyvale, CA), the feeding area of waste perimeter was walked. Geolink software (Michael Baker Corp., Moon Township, PA), an interface between the Trimble receiver and Arcview software (Environmental Systems Research Institute Inc., Redlands, CA), created a polyline, which was processed by Arcview into a polygon. Arcview and the Fujitsu monitor (CDW Corp., Vernon Hills, IL) were then used to calculate the area of the polygon. Cow growth, BCS, hay intake, fat depth, and waste data were ana-
lyzed as a complete randomized design with the GLM procedure of SAS (SAS Inst., Inc., Cary, NC) using pen as the experimental unit. The model included treatment and year and the 2-way interaction between treatment and year. When an interaction was not significant, the data was combined and reanalyzed. Differences were considered significant when P < 0.05, tendencies when 0.05 < P < 0.10, and nonsignificant when P > 0.10.
Economic Analysis of Winter Feeding Methods Production measurements and efficiency, time required for feeding, equipment and machinery inputs, and depreciation were used to develop an economic analysis model
to compare the 3 feeding methods using both 100- and 300-head reference herds in the model. The 2 herd sizes in the model represent the 2 most common cow herd sizes in North Dakota (North Dakota Agricultural Statistics, 2005). The model assumed a winter feeding period of 135 d and hay priced at $42.50/ton. The tapered-cone round bale feeders were valued at $800 each and assumed to feed 13 to 15 cows. The round bale processor was priced at $15,000. It was assumed that bale processor cutting flails would be replaced every 2,500 bales at a charge of $250, including labor. Tractor expenses were based on a 110-horsepower unit in all treatments, and allocation was based on typical use in other farm activities, of which win-
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Table 2. Three-year effect of hay feeding method on cow performance and hay intake Feeding method Round bale roll out Cow performance Cows, n Days fed Initial BW, kg Final BW, kg BW gain, kg ADG, kg Hay/cow, kg Yr 1 Yr 2 Yr 3 Hay/cow per day, kg Yr 1 Yr 2 Yr 3 BCS3 Initial Final BCS change Rib fat depth change, mm Yr 1 Yr 2 Yr 3
120 59 616.7 639.2 22.5a 0.381a 815a 1021a 917a 14.0a 18.6a 14.3a
PTO1-driven round bale processor 120 59 614.0 643.9 29.9b 0.507b 799b 1,067b 1,022b 13.6a 19.4b 16.0b
5.88 5.83 −0.04 −0.80a 1.32a −0.72a
5.77 5.80 0.029 −0.53b 1.18a −1.42b
P value Tapered-cone round bale feeder
SE
Yr
Trt
Yr × Trt
120 59 618.9 655.0 36.1b 0.611b
— — 11.75 10.83 2.72 0.046
— — 0.18 0.07 0.46 0.40
— — 0.96 0.58 <0.01 <0.01
— — 0.99 0.96 0.16 0.144
14.21 — —
<0.01 — —
<0.01 — —
0.004 — —
0.21 — —
<0.01 — —
<0.01 — —
0.0003 — —
5.94 6.01 0.07
0.087 0.083 0.081
<0.01 <0.01 <0.01
0.38 0.15 0.60
0.63 0.10 0.22
0.30c 2.22b −1.02c
0.38 — —
<0.01 — —
0.06 — —
0.39 — —
692c 925c 878c 11.9b 16.8c 13.7c
Values with unlike superscripts differ significantly (P < 0.05). PTO = power take-off. 2 Trt = treatment. 3 1 to 9 scale (1 = extremely thin; 9 = obese). a–c 1
ter feeding is one (Lazarus and Selley, 2002). Operation and ownership costs were $27/h, including a $7/h labor charge. Based on feeding time measured for each feeding method, the tractor time allocation
for filling the round bale feeders was calculated to be 3 min/bale and 5 min/bale for the bales either rolled out on the ground or shredded with the PTO-driven bale processor.
RESULTS AND DISCUSSION Cows were fed to maintain or improve their starting body condition prior to calving. Chemical analysis of the forages offered during the 3-
Table 3. Quantitative estimate of feeding area waste for each hay feeding method Feeding method Item Alfalfa-grass hay, kg Oat hay, kg 1 2
PTO = power take-off. Trt = treatment.
P value
Round bale roll out
PTO1-driven round bale processor
Tapered-cone round bale feeder
SE
Yr
Trt2
Yr × Trt
61.5 48.4
52.5 28.1
12.1 90.3
9.72 —
0.09 —
0.30 —
<0.01 —
Performance of Cow Hay Feeding Methods
Table 4. Three-year economic analysis comparing hay feeding methods for 100- and 300-head cow herds Feeding method
Item Hay consumed/d, kg Hay fed, metric tons2 100-cow herd 300-cow herd Hay cost/cow, $ Total hay cost, $ 100-cow herd 300-cow herd Equipment costs,3 $ 100-cow herd, per cow 300-cow herd, per cow Per 100-cow herd Per 300-cow herd Tractor operation costs,4 $ Cost per cow Per 100-cow herd Per 300-cow herd Total nonhay expense, $ Per cow, 100-cow herd Per cow, 300-cow herd Per 100-cow herd Per 300-cow herd Total expense, $ Per 100-cow herd Per 300-cow herd Total cost per cow, $ 100-cow herd 300-cow herd Hay cost, as % of total cost 100-cow herd 300-cow herd
Round bale roll out
PTO1-driven round bale processor
Tapered-cone round bale feeder
15.6
16.3
14.2
210.5 632.2 98.58
220.5 660.3 103.11
190.9 572.8 89.45
9,858 29,574
10,311 30,934
8,945 26,834
— — — —
12.98 7.62 $1,298 $2,288
5.13 5.13 $513 1,538
10.44 1,044 3,131
10.92 1,092 3,275
5.68 568 1,705
10.44 10.44 1,044 3,131
23.90 18.55 2,390 5,564
10.81 10.81 1,081 3,243
10,902 32,705
12,701 36,497
10,026 30,077
109.0 109.0
127.0 121.7
100.3 100.3
90.4 90.4
81.2 84.8
89.2 89.2
1
PTO = power take-off. Metric tons of hay fed over a 135-d period. Hay was priced at $42.50/ton. 3 Each bale feeder cost $800 and fed 13 cows in the analysis model. Bale feeders were depreciated over 12 yr. The bale processor cost $15,000. It was depreciated over 12 yr for the 100-cow operation and 7 yr for the 300-cow operation. Cutting flails were replaced every 2,500 bales at a total replacement cost of $250 including labor charge. 4 A 110-HP tractor was used regardless of system; model expense referenced from Lazarus and Selley (2002). Ownership expenses calculated assuming the tractor experienced typical use in other farm operation activities. Operation and ownership costs are $27/h including a $7/h labor charge. Tractor time is 3 min per bale for the bale feeder and 5 min per bale for roll out and bale processor systems. 2
yr investigation is shown in Table 1. Statistically, no year × treatment interactions for growth and BCS were identified; therefore, data for
the 3-yr study was pooled (Table 2). Cows fed using the conventional method in which bales are rolled out on the ground gained less (P <
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0.01) than when cows were fed with either the bale processor or tapered-cone round bale feeder. Starting, ending, and BCS change differed between years, but there were no differences due to treatment (P = 0.15). In addition to the subjective BCS, ultrasound fat depth measurements were used to quantify body condition change associated with each feeding method. Significant variation was measured between years (P < 0.01) and there was a tendency for increased fat depth within year (P = 0.06). During the first 2 yr of the study, cows fed using the tapered-cone round bale feeder had greater rib fat depth increase than either the roll out or bale processor methods. During the third year of the study, rib fat depth change declined from the start to the end of the test feeding period, but the magnitude of the decline did not differ between feeding methods. Cows used during the third year were in better overall body condition at the start of the test feeding period, which may have contributed to the observed condition decline. The decline suggests that the level of energy supplied to all cow groups was not sufficient to maintain the initial BCS. Hay offered to maintain BCS was greatest for cows fed with the bale processor, intermediate when bales were rolled out, and the least when cows were fed using a tapered-cone round bale feeder (P < 0.01). On average, when compared with the tapered-cone round bale feeder, 5.0 and 15.3% more hay was offered per cow using the roll out and bale processor methods, respectively. Waste contributed to the increased amount of hay required among the roll out and bale processor cow groups (Table 3). An estimate of waste suggested that type of hay and firmness of bales played a significant role in success with the tapered-cone round bale feeder. When dense alfalfa-grass hay bales were tied tightly and strings were not removed for feeding, waste
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around the tapered-cone round bale feeder was 4.3 to 5.0 times less than either the roll out or bale processor methods, respectively. However, when loose, poorly tied oat hay bales were fed in the tapered-cone round bale feeder, waste was numerically decreased but did not differ with the bale processor (P = 0.30). Bale processors are used for all sorts of hay whether coarse or fine textured and shred the forage as it is being discharged from the machine, reducing particle size. Shredding with the bale processor is associated with considerable dust (wasted feed) and fine particles that, when fed on the ground, are difficult for cattle to pick without eating dirt as well. Our research team observed that for maximum effectiveness when using a bale processor to shred hay, a bale processor would be best suited to deliver hay into bunks. However, our study did not evaluate offering shredded hay in bunks as one of the treatments. Over the 3-yr period, these data suggest that hay waste is minimal with the taperedcone round bale feeder when bales are dense, adequately tied, and strings are not removed prior to feeding. Economic model analysis suggests that feeding with a tapered-cone round bale feeder offers substantial cost savings per cow arising from a reduction in the amount of hay offered, equipment cost, and feeding time. Wintering cost per cow for the 100-cow reference herd was $109, $127, and $100 for rolling out bales, shredding with a bale processor, and feeding bales in a ta-
Landblom et al.
pered-cone round bale feeder, respectively (Table 4). The per-cow cost using a 300-cow reference herd was $122 compared with $127 for the 100-cow reference herd fed with the processor due to differences in the rate of depreciation between the 2 herd sizes in the economic model. Using a bale processor to shred bales into windrows before feeding was the most expensive due to greater equipment ownership cost and greater hay intake per cow necessary to maintain a comparable condition compared with the tapered-cone round bale feeder. Rolling bales out and shredding into windrows with a bale processor increased hay consumption and winter feed cost.
IMPLICATIONS Using dense, properly tied bales, the tapered-cone round bale feeder was a superior winter hay feeding method when compared with either rolling bales out on the ground or shredding on the ground with a bale processor. Tapered-cone round bale feeders reduced waste, decreased the amount of hay required per cow from 5.0 to 15.3%, and decreased wintering cost per cow while maintaining body condition. Economic analysis for the 3 wintering seasons identified an economic advantage for using the tapered-cone round bale feeding method.
ACKNOWLEDGMENTS Partial funding for this project was provided by the North Dakota
Beefline Initiative, North Dakota State University, Agricultural Experiment Station.
LITERATURE CITED Baxter, H. D., B. L. Bledsoe, M. J. Montgomery, and J. R. Owen. 1986. Comparison of alfalfa-orchardgrass hay stored in large round bales and conventional rectangular bales for lactating cows. J. Dairy Sci. 69:1854. Belyea, R. L., F. A. Martz, and S. Bell. 1985. Storage and feeding losses of large round bales. J. Dairy Sci. 68:3371. Buskirk, D. D., A. J. Zanella, T. M. Harrigan, J. L. Van Lente, L. M. Gnagey, and M. J. Kaercher. 2003. Large round bale feeder design affects hay utilization and beef cow behavior. J. Anim. Sci. 81:109. Eversole, D. E., M. R. Browne, J. B. Hall, and R. E. Dietz. 2000. Body Condition Scoring Beef Cows. Virginia State University Cooperative Extension Service Publication. http:// www.ext.vt.edu/pubs/beef/400-795/400795.html Accessed April 2007. Huhnke, R. L. 1987. Large round bale alfalfa storage. Appl. Eng. Agric. 4:316. Lazarus, W., and R. Selley. 2002. Farm Machinery Economic Cost Estimate for 2002. Univ. Minnesota Ext. Serv., St. Paul. Miller, A. J., D. B. Faulkner, R. K. Knipe, D. R. Strohben, D. F. Parrett, and L. L. Berger. 2001. Critical control points for profitability in the cow-calf enterprise. Prod. Anim. Sci. 17:295. National Research Council. 1996. Nutrient Requirements of Beef Cattle. 7th rev. ed. Natl. Acad. Press, Washington, DC. North Dakota Agricultural Statistics. 2005. North Dakota Agric. Statistics Serv. Bull. No. 74:83. Fargo, ND. Swenson, A. 2006. North Dakota Farm and Ranch Business Management Annual Rep. North Dakota State Univ. Ext. Serv., Fargo. Ultrasound Guidelines Council. 2007. Iowa Falls, IA. www.aptcbeef.org/site/298/default.aspx Accessed April 2007.