Molasses as an Alternative Energy Feed Source for Organic Dairies

Final Report for GNE10-011

Project Type: Graduate Student
Funds awarded in 2010: $14,426.00
Projected End Date: 12/31/2010
Grant Recipient: University of New Hampshire
Region: Northeast
State: New Hampshire
Graduate Student:
Faculty Advisor:
Dr. Andre Brito
University of New Hampshire
Faculty Advisor:
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Project Information

Summary:

Organic dairies are faced with the challenge of sourcing and purchasing organic feed grains. These grains particularly corn, are often in short supply and highly expensive. This study replaced the traditional corn meal (CM) found in many organic dairy rations with liquid molasses (MOL). Molasses was chosen for its high palatability and high energy content. To complete this study 20 lactating Jersey cows from the Burley-Demeritt Organic Dairy Research Farm of the University of New Hampshire (UNH) were utilized to investigate the effects of liquid MOL vs. CM on milk production, milk composition, and nitrogen (N) utilization. Income over feed cost (IOFC) analysis was also done to determine whether profitability is improved by feeding MOL over CM. The feeding trial began in June 2010 and ended in September 2010 with most of the laboratory analyses completed in 2011. Cows in this study had access to mixed species pasture for about 18 h/day from June to mid-September. Along with pasture a ration consisting of approximately 2.0 kg of dry matter (DM) from either MOL or CM along with 3.0 kg of DM from a grass-legume mix baleage was fed to cows twice daily. Cows fed MOL had increased (P < 0.01) supplement (MOL + baleage) DM intake (DMI). Pasture DMI was numerically higher in cows supplemented with MOL resulting in numerically higher total DMI (supplement + pasture). Milk yield was also numerically higher (+1.0 kg/d) in cows fed MOL vs. CM. Concentrations of milk urea N (MUN) and plasma urea N (PUN) were both significantly decreased in cows fed MOL vs. CM indicating improvement in N utilization. However, despite the slight numerical increase in milk yield in cows fed MOL, the cost of feeding it was $0.24/lb higher compared to MOL resulting in reduced IOFC.

Introduction:

As milk prices fluctuate and input costs increase, dairy farms seek lower-cost feed alternatives to maintain or improve milk production while reducing feed costs to improve overall farm profitability. This has been most evident within the organic dairy sector, as organic grain prices have been traditionally higher relative to conventional grain prices. Thus, organic dairy farmers have experimented with a variety of supplemental grains and alternative feed sources, including molasses.
Sugar cane MOL is a rich source of sugars, particularly sucrose, is available in organic form, and may be a viable supplement option in place of CM. However, there is little literature available that evaluates MOL as the only supplement for grazing dairy cows. Anecdotal results, as reported by organic dairy farmers, are mixed - some farms use MOL successfully while others report major milk production or body condition losses. Also, it has been anecdotally proposed that MOL has three times more energy than CM, allowing for a lower feeding rate. While there is research available that evaluated MOL as an energy supplement in confined dairy cows. There is no specific data available in the scientific journals regarding the impact of using MOL as the only supplemental source of feed to grazing dairy cows. Additionally, there is no research data available to verify that molasses is higher in energy, as it is generally considered to be equivalent to CM.
Feeding a high energy source like MOL or CM is critical for balancing the dietary needs of grazing dairy cattle. Pasture tends to be very rich in rumen-degradable protein which is transformed into ammonia in the rumen. A high energy feed source is necessary to balance the rumen-degradable protein which allows for the conversion of ammonia into microbial protein. If a high energy feed source is not available, ammonia will be detoxified to urea in the liver and lost as N in urine, which is major source of environmental pollution. Not only does the lack of a high energy feed source result in increased N excretion to the environment, it can also lead to some serious negative impacts on the dairy cow (NRC, 2001). The process of detoxifying ammonia to urea through the urea cycle in the liver is an energy expensive process that requires the cow to draw energy from her body stores (NRC, 2001). Cows with high levels of circulating urea tend to lose body condition and suffer from poor reproductive performance. Sucrose present in MOL is more quickly degraded in the rumen than starch present in CM (Chamberlain et al., 1993), thus suggesting that feeding MOL can balance the supplies of energy and degradable protein in the rumen leading to improved N utilization in grazing dairy cattle.
We hypothesized that MOL supplementation will enhance N utilization and microbial protein synthesis which may be responsible for the positive responses in milk production, milk composition, and body condition anecdotally observed by organic dairy farmers currently feeding MOL.

REFERENCES:
National Research Council. 2001. NRC. Nutrient requirements of dairy cattle. 7th rev. ed. Natl. Acad. Sci. Washington, D.C.

Chamberlain, D. G., S. Robertson, and J.J . Choung. 1993. Sugars versus starch as supplements to grass silage: Effects of ruminal fermentation and the supply of microbial protein to the small intestine, estimated

Sanderson, M. A., C. A. Rotz, S. F. Fultz, and E. B. Rayburn. 2001. Estimating forage mass with a commercial capacitance meter, rising plate meter, and pasture ruler. Agron. J. 30:1281-1286.

Project Objectives:

Objective 1: Evaluate the impact of molasses vs. corn meal supplementation on enhancing milk production, milk components, and microbial protein synthesis while reducing N output to the environment in pasture-based systems. All laboratory analyses regarding milk composition (e.g., fat, protein, lactose, and MUN) were completed and statistically analyzed. All laboratory analyses regarding feed nutrient composition (e.g., DM, crude protein, starch, sucrose, amino acids, neutral detergent fiber, acid detergent fiber, crude fat, etc.) were completed and analyzed. All laboratory analyses regarding urinary N excretion (e.g., total N, urea N, and ammonia N), estimation of urinary volume (creatinine), and estimation of microbial protein synthesis (allantoin and uric acid) were completed. All analyses regarding animal performance (e.g., milk production, body weight gain, and nutrient intake) were completed and statistically analyzed. All plasma analyses (e.g., PUN, nonesterified fatty acids, and amino acids) were completed. Milk fatty acid analysis is being currently analyzed in the laboratory of Dr. Yvan Chouinard (University Laval; Québec City, Quebec, Canada) and will be included in future presentations and publications of this project. With the exception of milk fatty acid analysis, this objective has been completed. Statistical analyses of all urinary data, milk fatty acids profile, plasma nonesterified fatty acids, and plasma amino acids and will be completed and included in future outreach activities, as well as popular press and scientific publications.

Objective 2: Evaluate the impact of molasses vs. corn meal supplementation on enhancing farm profitability. Income over feed cost analyses were completed.

Cooperators

Click linked name(s) to expand
  • Dr. Andre Brito
  • Dr. Kathy Soder

Research

Materials and methods:

Housing and Feeding of Dairy Cattle

Twenty lactating Jersey cows housed at the University of New Hampshire’s Burley-Demeritt Organic Dairy Research Farm were assigned randomly to one of two supplementation treatments: 1) MOL (12% of diet DM) or 2) CM (12% of diet DM). The supplements were top-dressed on a grass-legume baleage (fed at 18% of diet DM) and were fed individually twice daily following milking using Calan doors (American Calan, Northwood, NH) to assure each cow received the correct treatment. Molasses and CM averaged (% of DM): 5.35% vs. 7.85% CP, 68.9 vs. 0.12% starch, and 1.53 vs. 50.1% sucrose, respectively.

Pasture Sampling and Management

Cows were segregated by treatment into two grazing groups. Each group was provided a new paddock averaging 0.10 hectares twice daily. Grazing times were (from about 08:00 to 14:00 and then again from 18:30 to 04:30) from early June to mid-September for a total of approximately 110 days. Group pasture intake was estimated using pre- and post-grazing pasture height measurements using a pasture ruler and a rising plate meter (Sanderson et al., 2001). Pasture herbage samples representative of that harvested by the grazing cows were collected for nutrient analyses by wet chemistry (e.g., DM, crude protein, starch, sucrose, amino acids, neutral detergent fiber, acid detergent fiber, crude fat, etc.). Supplements were sampled weekly and composited monthly for nutrient analyses (see above). Clipped herbage was collected, weighed, and sampled for botanical composition (proportion of legumes, grasses, and weeds).

REFERENCES:
Sanderson, M. A., C. A. Rotz, S. F. Fultz, and E. B. Rayburn. 2001. Estimating forage mass with a commercial capacitance meter, rising plate meter, and pasture ruler. Agron. J. 30:1281-1286.

Milk, Blood, and Urine Sampling

During each of four collection periods (June, July, August and September), blood samples were collected twice (am and pm), cows were weighed on three consecutive days, and milk samples were collected on two consecutive days (am and pm). Daily milk yield was recorded for the duration of the trial.
Milk samples were analyzed for milk fat, protein, lactose, and MUN by mid infrared spectrophotometry (Dairy One Cooperative Inc., Ithaca, NY). Plasma samples were analyzed for PUN, nonesterified fatty acids, and amino acids.
Spot samples of urine were collected twice daily after each milking on 2 consecutive days every month during the grazing season, and analyzed for allantoin and uric acid for estimation of microbial protein synthesis and for creatinine for estimation of urinary volume. Urine samples were also analyzed for total N, urea N, ammonia N.

Data Analyses

The experimental design was a completely randomized block design. Cows were blocked by parity, stage of lactation, and milk production, and assigned to one of two supplementation treatments. Data was analyzed using the MIXED procedure of SAS (SAS Institute Inc.,Cary, NC) for a completely randomized design with repeated measures over time.

Economic Analysis

Economic analysis was conducted to determine IOFC using market prices for CM ($0.16/lb) and MOL ($0.40/lb) obtained from Lakeview Organic Grain. Milk was sold to Dairy Farmers of America Inc. at an average price of $0.30/lb (see Table 2).

Strategies Adopted to Engage Organic Dairy Farmers
Organic dairy farmers were engaged through participation in focus group interviews, presentation in farmers’ workshops (e.g., 2012 Vermont Organic Dairy Workshop), popular press articles (e.g., NODPA news, GRAZE), and fact-sheets.

Research results and discussion:

Intake of supplement (baleage + MOL or CM) was significantly greater (P < 0.001) for cows fed MOL vs. CM (Table 1). Pasture and total DMI were numerically greater for cows fed MOL than for those fed CM. Likewise, no significant differences (P > 0.05) were observed for milk yield and yields and contents of milk components comparing these two energy sources. However, cows fed MOL had lower MUN (P = 0.03) and PUN (P < 0.01) compared to those fed CM, suggesting improvement in N utilization. There were no significant differences (P > 0.05) in body weight gain between treatments. Economic analysis showed a $-0.46/day difference in total IOFC between MOL and CM. Total IOFC for CM averaged $6.41/day while that for MOL averaged $5.95/day (Table 2)

Discussion

Cows fed the MOL supplement consumed significantly more DMI than those fed the CM supplement likely as a result of the higher palatability of MOL compared to CM. Although the increase in pasture DMI cannot be explained by MOL palatability, it was numerically higher in cows fed MOL. The increase in DMI from pasture and supplement in cows fed MOL resulted in numerical increases in both milk yields and milk components.
Both the MUN and PUN were significantly lower for the cows fed MOL compared to those fed CM, indicating an improvement in N utilization. Because MOL is more quickly degraded in the rumen than CM, it is possible that cows fed MOL were more efficiency converting ammonia into microbial protein leading to reduced MUN and PUN when compared to CM.
Based on IOFC calculated using CM, MOL and milk prices at the time of study it does not appear economically beneficial to supplement grazing Jersey dairy cows with MOL.

Research conclusions:

In general, MOL performed similarly to CM at the low feeding levels of the current study. While greater levels of MOL supplementation may change the results, cost of feeding as well as possible detrimental effects of too much sucrose in the rumen must be considered as reduced nutrient digestibility may result. The decision to feed MOL or CM as an energy supplement to grazing dairy cows should be based on the cost of each feed on a DM basis. It is important to note, however, the MOL did reduced MUN and PUN strongly indicating the less N was excreted to the environment. The close collaboration of the project PI with Extension personnel from UNH Cooperative Extension, UVM Extension, NRCS, NOFA-VT, NODPA, Organic Valley, and StonyField will leverage project results. Organic dairy farmers can now make informed decisions about the feasibility of using MOL as an alternative energy source to CM in their family farms.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Results of this research were presented by Dr. Brito at the 2011 Northeast Pasture Consortium annual meeting. A poster detailing this project was presented by Dr. Brito at the National Joint Meeting in New Orleans July 2011. Dr. Brito also discussed this research at the Wisconsin Grazing Conference held during the World Dairy Expo in Madison-WI last October. Kristen Greene a former UNH undergraduate presented a poster with this research at the UNH Undergraduate Research Conference which took place in April, 2011. Popular press articles based on this research and other projects in collaboration with NRSC and the USDA-ARS were published on the AgriView website, GRAZE magazine, and NODPA news. Specifically, the fact sheet detailing results of this research and other related research conducted on MOL vs. CM was distributed directly to organic dairy farmers at grazing field days and events.

Results of this research were presented at:
• Northeast Pasture Consortium annual meeting (February 2011, State College, PA) http://grazingguide.net/2011/06/effects-of-cornmeal-and-molasses-on-milk-production/
• UNH Undergraduate Research Conference (April, 2011, Durham, NH)
• American Dairy Science Association/American Society of Animal Science annual meetings (July 2011, New Orleans, LA)
• WI Grazing Conference (January 2012, Eau Claire, WI).
• Popular press publications about the project
o http://www.agriview.com/news/dairy/molasses-or-corn-meal-to-grazing-cows-matter-of-cost/article_ba61efec-da31-11e0-8e1f-001cc4c03286.html

A fact sheet (ftp://ftp-fc.sc.egov.usda.gov/NY/news/factsheets/molasses_case_study.pdf ) was developed and distributed at grazing field days and events.

Publications authored by PI:
1) Ross, S., A. F. Brito, K. J. Soder, K. Greene, A. Green, and P. Y. Chouinard. 2011. Effect of molasses or cornmeal on milk production and nitrogen utilization of grazing organic dairy cows. J. Dairy Sci. 94 (E-Suppl. 1):317. http://m.jtmtg.org/PresDetail.aspx?view=sci&selectby=daytime&dt=7/12/2011&ap=AM&sespage=1&sessionID=4556&prespage=1&presID=46553&prestype=abs

2) Soder, K.J., A.F. Brito, and K. Hoffman. Current research on molasses as an alternative energy source for organic dairy herds. Northeast Organic Dairy Producers Alliance newsletter. Vol. 10, Issue 2, pp. 30-32. 2010. (Popular Press Publication) http://www.nodpa.com/production_forage_molasses_april_2010.shtml

3) Soder, K. J., K. Hoffman, and A. F. Brito. 2010. Effect of molasses, corn meal, or a combination of molasses plus corn meal on ruminal fermentation of orchardgrass pasture during continuous culture fermentation. Prof. Anim. Scientist. 26:167-174. http://pas.fass.org/content/27/1/35.abstract

4) Soder, K. J., A. F. Brito, and K. Hoffman. 2011. Effect of molasses supplementation and nutritive value on ruminal fermentation of a pasture-based diet. Prof. Anim. Scientist. 27:35-42. http://pas.fass.org/content/27/1/35.abstract

5) Soder, K.J., A.F. Brito, S. Ross, and K. Hoffman. 2011. Molasses versus grain: what the research says. GRAZE magazine. Vol.18, No. 7, pp. 8-9. 2011. (Popular Press Publication).

Project Outcomes

Project outcomes:

Feed costs for MOL were $0.26 higher per pound compared to CM. Income over feed costs calculated using milk yield, milk price/lb, MOL price/lb, CM price/lb, baleage price/lb, and pasture price/lb is shown in Table 2. The economic analysis showed a $0.46 difference in IOFC, indicating that despite the numerical increase in milk yield for cows fed MOL it was not enough to make up for its higher cost and the increased pasture DMI. However, significant changes in MOL or CM prices may dictate the economic feasibility of utilizing MOL as a substitute for CM in the future.

Farmer Adoption

Prior to conducting this study organic dairy farmers in the Pennsylvania area had expressed interest in using MOL as an alternative energy source. These farmers were interested primarily in the economics of substituting MOL for CM but also wanted to know how MOL would impact cow health and performance. Based on conversation with and feedback from organic dairy farmers, feed costs would determine the implementation of any supplementation strategy including the use of MOL. Some organic dairy farmers in the region are currently using MOL but its high price is preventing a more widespread adoption.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

The seemingly ever rising price of organic grain led to the development of this study and use of MOL as an alternative feedstuff. Based on the results of this study MOL may be a suitable substitute for CM in some cases. The decision to utilize MOL over CM must be carefully decided on a farm to farm basis based on current grain and milk price. A series of focus groups conducted by the PI showed that organic dairy farmers continue to express interest in research that will improve profitability of organic dairy systems. Therefore, research should be conducted on grazing supplementation strategies for improving profitability while reducing the environmental impact of organic dairy farms in the Northeast. Organic dairy farm profits are shrinking rapidly due to a combination of skyrocketing feed costs and low milk prices. This lowering profit margin will compromise the long term sustainability of organic dairy farming in the region. Farmers need to make informed decisions about grazing management and feeding strategies to remain economically viable.

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.