Final Report for SW96-021
[Note to online version: The report for this project includes tables and figures that could not be included here. The regional SARE office will mail a hard copy of the entire report at your request. Just contact Western SARE at (435) 797-2257 or firstname.lastname@example.org.]
Research projects at the site examined the effects of controlled grazing on the environment, livestock performance and profitability, and analyzed the potential of spring calving on annual rangeland. The same site was used as a demonstration project on low-stress livestock handling, and appropriate tools and equipment for pasture management and livestock control. Educational projects included the 5 Grazing Academies and 3 project field days.
The 250-acre site was subdivided into 23 rangeland paddocks and stocked with 20 cows and heifers during the two years of the project spring calving occurred. Water was developed to every paddock using both permanent and portable water points. Innovative technologies were demonstrated with regards to fencing, water development, and pumping with solar and ram pumps. Grazing planning was used to ensure rest periods of 30-45 days during fast growth and 90-120 days during slow growth. Carrying capacity was estimated at the end of the growing season and stocking rates were adjusted according to these estimates. Implementation of controlled grazing principles allowed stocking rate to increase 51.4% over historical levels. Species composition did not change during the life of the project. The application of concentrated animal impact removed thistle infestations.
The project herd was established consisting of fall calving cows. Calving season was switched to spring to match the animal's greatest demand with nature's largest supply, eliminating the need to purchase energy off the farm (hay) and feed to the animals. Cows were in body condition score (BCS) 7.9 at calving in 1998. In 1999, they were in BCS 6.6 at calving. Conception rates were 100% for the two years breeding season occurred in the summer. The calving interval for cows bred in summer 1998 to calve in spring 1999 was 357 days. The calving rate for 1998 and 1999 spring calving cows was 100%. Weaning rate was 92% for both years. Heifer conception rates were 80%. They calved for the first time in spring 1999 at BCS 4.7.
Comparing the calf weights of fall- and spring-born calves at similar ages revealed a 53-pound advantage for six-month-old fall calves. By 11 months of age, there was no difference. Highest economic returns of $250 per cow were generated with this approach.
Keeping cows and calves together for as long as possible improved weight gain on the calves. Calves weaned at six months of age were 30 pounds lighter at selling than calves weaned at nine months of age. Body condition was the indicator for weaning. Cows with calves were weaned when cows reached a BCS 5; they must be weaned one to two months before they calve again, even if their body condition is adequate.
Forage samples were collected on a monthly basis for the purpose of developing a supplement that made up for all deficiencies except for energy - which would come from the land. Three years of data show crude protein declining from 21% in February to less than 4% by October. Energy levels declined 40% between March and July and then remained relatively stable.
• Demonstrate controlled grazing on foothill/annual grassland and irrigated pasture
• Demonstrate monitoring procedures to assess range condition and trend and livestock performance
• Teach research based controlled grazing practices to livestock producers
• Compare effects of controlled grazing to conventional grazing on livestock production and economic performance
• Compare effects of controlled grazing to conventional grazing and livestock exclusion on plant communities
• Determine effects of controlled grazing on trace mineral nutrition of cattle
• Determine effects of controlled grazing on parasitism in cattle
Objective: Demonstrate controlled grazing on foothill range/annual grassland and irrigated pasture.
The project ranch is a 250-acre watershed located at the UC Sierra Research and Extension Center. When first starting the project, the site consisted of 4 paddocks and 2 permanent watering points. Existing fencing and watering sites were ignored in planning for site because it might have inhibited the choice of a more favorable layout. The final design was competed in February 1996 and implemented by June 1996. The layout consisted of 23 rangeland and two irrigated pasture paddocks. Irrigated pasture paddocks were strip-grazed using 12-30 temporary paddocks. After 1997, irrigation was terminated on the project site.
The final layout included 4 smaller teaching paddocks for the California Grazing Academy and 3 grazing exclosures. Four permanent water points and over a mile of polypipe were established and laid throughout the watershed. An additional 12 water points were established using portable water hydrants. Water can then be delivered into portable watering troughs.
The use of portable water systems builds extra flexibility in providing additional water points. Polypipe laid above ground has been used to deliver the water. The only major problem encountered was extremely hot water (120 degrees) being delivered to smaller portable water troughs in the irrigated pasture. This required burying approximately one mile of pipe to lower water temperatures to 80 degrees or less in the summer.
Alternative methods of pumping were explored using gravity and solar power. Gravity power utilized a ram pump. We have been able to pump 15 gallons an hour with 25 feet of head with a 1 inch ram pump using 5 foot of fall. This translates to 360 gallons a day.
Solar pumping is accomplished using an M3 solar pump. This pump is powered by a 75 watt solar panel and can deliver up to 7.5 gallons a minute with 3 foot of head and 2 gallons a minute with 23 feet of head. The pump floats in the water and is connected to the panel by a submersible electric cable. We have been very pleased with the performance, portability, and reliability of this pump.
Two wire paddock subdivisions were accomplished using a smaller gauge hi-tensile wire as part of a fencing system called Spider fencing. The use of Spider fencing enabled rapid fence construction with a minimal need for bracing. Flexibility of the spider wire was demonstrated in 1998 as an oak tree fell on part of the fence line. After 30 cuts with a chain saw to remove the tree, the wire popped back up in place with no need for repair. The fence was powered with a solar powered low impedance energizer.
Grazing planning and monitoring were developed using a grazing chart. This chart was used to plot future moves into different paddocks. In addition to planning, the chart was used to record days of grazing and number of stock days for each paddock, cow weight and body condition, and amount of monthly rainfall. Rest periods were 30-45 days during fast growth and 90-120 days during slow growth or the dormant season. Rest periods were timed for the needs of perennial grasses, which comprise approximately 10% of the project area. Graze periods varied from 1-2 days during fast growth to 5-8 days during slow or dormant growth.
The project herd was established with the principles of a high production / low cost nutrition program. These principles are:
• Time of calving to match demand of the cow with supply of nature
• The cow's ability to store and relinquish energy in the form of body fat
• A balanced supplement that accounts for forage deficiencies - except energy.
Using this approach, the land is the only source of energy. In order to implement this approach, you must match demand with supply. We switched the cow herd from fall to spring calvers because of the ample forage supplies in spring.
We timed calving to begin approximately April 1st to give cows a month on adequate feed to regain body condition. The most important factor in getting a cow to have a calf every year is body condition at calving. Cows in adequate body condition are much more likely to re-breed on schedule than cows in poor body condition.
The project herd was established with 27 pregnant cull cows in June 1996. The cows were predominately a Hereford X Angus cross and weights ranged from 1,015 to 1,365 pounds. Body condition (measure of the relative fat cover of an animal) averaged 5.7 (Scores range from 1-9 with 1 being emaciated to 9 being obese). Calves were born from October 20 until December 23. One cow died while giving birth. Another cow did not calve. Cows calved at a BCS 5.
In January 1997 the herd consisted of 25 lactating cows (calves were 20-70 days of age) and one open dry cow. Rest periods in January and February were 80-100 days. Grazing was severe as little growth was occurring due to lack of rain. Despite heavy rains in a 5 day period around the first of the year, little subsequent moisture fell in January-March. Growth slowed to a standstill. Cows received no hay or supplement.
Cow body condition dropped 0.6 during this period - 4.3 to 3.7. These scores indicate that cows would have difficulty re-breeding in time to have a calf in 1997 if we were attempting to stay with fall calving. Since we were switching to spring calving, the cows would have time to recover to be bred in the summer.
Due to lack of forage growth, one dry cow and 5 lactating cows were culled in January, leaving us with 20 pair. Continued dry weather in March and April meant more culling would be needed to make sure the herd had sufficient forage supply. We decided to maintain the herd at 20 pair until after the California Grazing Academy (end of April). The week after the Academy we culled 7 cows and weaned and shipped the steer calves. This reduced number down to 13 cows and 10 heifer calves.
Heifer calves were not weaned until breeding season began June 25th. Breeding season lasted 47 days. Two Angus bulls were used to service the cows. After breeding season, the calves were combined with the cows to form one herd. This increased the number of paddocks available per herd, increased stock density and reduced labor requirements.
Conception was confirmed at 100% in December. Cows went into winter at body condition score 7 and increased to an 8 by the time calving season began. In contrast to 1997, the El Nino of 1998 provided excellent forage conditions throughout fall, winter, and spring.
Cows began calving March 31, 1998 and ended on May 11th. Heifers had to be separated from the calving cows because they were curious about the calves. Several people had expressed concern about the potential for udder problems, cows producing too much milk, and pneumonia. We did not encounter any problems in our first year of spring calving.
The herds were combined when breeding season began on May 28th. At this time, half of the cows (earliest calvers) and half the heifers were put with 2 Angus bulls. This was the early calving group. The remainder of cows and heifers were put with the bulls on June 21st. This was the late calving group. Breeding season ended on August 10th.
The two calving groups were implemented to prepare for future expansion of the project. This would be the first step in helping producers determine when spring is. The early calving group would calve closer to the start of rapid growth, while the late calving group would calve a month later. The late calving would have the opportunity to graze lush growth prior to calving and put on condition. The early calving group would not have an opportunity to graze lush forage prior to calving, but would have adequate feed after calving.
Objective: Demonstrate monitoring procedures to assess range condition and trend and livestock performance.
Range Condition and Trend
In spite of stocking reductions made in response to severe spring drought in 1997, the project site produced 10,674 stock days). This was a 30% increase over historical stocking days. In 1998, the amount of stock days further increased to 12,421. This is a 26% increase over the previous year and a 64% increase over historical stock days.
Paddocks had an average of 800-1200 pounds of residual dry matter from the 1996-97 and 1997-98 growing seasons left at the start of new growth in 1997 and 1998 (visual estimate).
Two years of data is insufficient to draw conclusions, however the data does show an increase in perennial grasses and clover and less bare soil on irrigated pastures in 1997. Transects did not detect any significant changes on rangeland paddocks after one year. However, several photo-points showed dramatic changes in cover. The color photos show pictures of photo-point 4 taken in December 1995 and December 1996 (seven months after the start of the project).
Cows have been weighed and body condition scored on a monthly basis since July 1996. Switching calving season from fall to spring saw body condition rise 52% from 3.7 in January 1997 to 7.7 in January 1998. Cows calved at BCS 5 in the fall of 1996 and BCS 8 in spring 1998.
The 1998-99 year is the first normal production year for the project. Cows calved in spring, were re-bred in the summer, lactated until early winter, and then calved again in spring 1999. In December 1998, body condition score was 35% higher than in December 1996. Cows in early to mid-lactation on low quality and quantity fall feed have a difficult time maintaining the needed body condition to get re-bred. The only way to maintain condition is to purchase an energy source and feed to the cows.
The cows had a calving interval of 357 days. This is almost unheard of, according to ranchers when they saw the results.
Spring calves gained better than the fall calves through the first 3 months after calving. The last two months, the fall calves gained rapidly on lush spring feed and weighed 62 more pounds at the end of 7 months. The spring calves weighed the same as the Fall 96 heifers did at 11th months of age.
Two weaning treatments were applied to the Spring 98 calves. On October 26, six cows with the lowest body condition scores were weaned (average BCS of 5.3). The other six cows kept their calves (average BCS of 6.8) until January 21st. Weaning was accomplished by separating the cows from the calves from one weigh day to the next (29 days for Oct-Nov and 36 days for Jan -Feb). The replacement heifers were also combined with the weaned calves. Face to face contact was maintained for the first couple of days and then the cows were moved off. When the calves were re-combined, they mothered up, but did not nurse. This method minimizes the amount of time that 2 separate herds have to be maintained.
The weaned cows remained at BCS 5.3 though March and then began to increase. The late weaning group declined from a BCS 6.8 in October to a 5.7 at January weaning. They declined to a 5.4 in February and then began to increase. On average, cows in 1999 were a BCS 5.2 in February and increased to a 6.6 in April when the majority of cows calved. They further increased to a 8.1 by June
The early and late weaned groups gained the same amount of weight the first month
post -weaning. The late weaning group gained 35 more pounds in the second month. They maintained this advantage throughout the remaining part of the stocker period until the calves were sold the first week of April, 1999.
Retained heifer calves only gained 0.4 lbs a day from June 25 to November 25, 1997, going from 506 to 571 pounds - a period of 153 days. Over the next 153 days, heifer calves gained 2.3 pounds a day and grew to 967 pounds by May, 1998. Heifers had an average daily gain of 1.3 pounds at 65% of mature body weight. This period is critical for heifers to be gaining at least a small amount of weight in order for them to have the ability to empty and re-fill cells with fat. This is what allows us to use the cow itself as a source of energy during lean feed times.
Heifers were bred in Summer 1998 at a BCS of 6. Heifer reproductive performance reveals an 80% conception rate and 87.5% weaning rate. Heifers began calving at BCS 4.4 in March and continued calving at BCS 4.7 in April. They increased to BCS 5.2 by August, 1999.
Objective: Teach research based controlled grazing practices to livestock producers.
California Grazing Academy
During the 1996-98 period, three California Grazing Academies were held. During this time, 104 ranchers were trained on the practical application of research-based controlled grazing principles. The unique aspect of Academy is the emphasis on hands-on participant involvement. Participants learn by actually applying the principles taught in real pastures with live cattle. Using the project site enables ranchers to see controlled grazing under field condition, view and use innovative hardware, apply principles of low-stress livestock handling, and develop monitoring skills.
Project Web Site
In March 1997 we posted a web site on the Internet. The site includes almost 50 papers on grazing, ecology, nutrition, fencing, and low-stress livestock handling. It also includes information about project events and links to other useful web sites. We have had over 6,400 hits on the site.
California Grazing Academy Audio Tape Series
Four audio tape programs (one on each side of two cassette tapes) were developed by Dave Pratt, Roger Ingram, and Barbara Reed to provide follow-up support for Grazing Academy alumni and introduce other ranchers to controlled grazing principles. Each set of tapes includes a small workbook.
Project Field Days
Project field days were held in 1996, 1997, and 1999 for a total of 120 ranchers. Each field day featured educational programs, project tour, and a project update.
Objective: Compare the effects of controlled grazing to conventional grazing management on livestock production and economic performance.
The proceeding chart compares spring calving and selling at weaning, spring calving and retaining calves as stockers, and fall calving and selling at weaning. Opportunity costs were included in the analysis to reflect the true economic cost of not capitalizing on an alternative investment. We have shown opportunity cost as 10% of the opening inventory value.
Calves born in the fall were 60 pounds heavier at weaning than calves born in the spring. The weight advantage would be offset by having to feed one ton of hay per cow in order to have a successful breed back. Feed conditions in California in the fall are at their lowest with regards to quantity and quality.
Spring calving cows did not require any hay. Feed conditions in California in the spring are at their highest with regards to quantity and quality. Retaining claves at weaning offers the potential for increased economic returns.
The data included here is based on the first two spring calving seasons of the project and should not be interpreted as a recommendation. The key point is that an economic analysis is run on different situations to allow an individual to make an informed choice.
Objective: Compare the effects of controlled grazing to grazing exclusion and conventional grazing management on plant communities.
Three grazing exclosures were developed on the project site at the following locations: riparian area, dryland perennial grass area, and annual rangeland. Transect data has not indicated any significant changes to plant communities.
Objective: Determine the effects of controlled grazing on trace mineral nutrition of cattle.
Monthly forage samples have been taken on the project site since July 1996. These samples are analyzed for crude protein, net energy maintenance, calcium, phosphorous, magnesium, potassium, sodium, iron, zinc, copper, manganese, and molybdenum. These samples are taken to develop a supplement that accounts for all forage deficiencies except energy - which is coming from the land.
From a high of over 20% in late winter, protein will decline to around half that by the end of the growing season in May. Protein will continue to decline throughout the summer to less than 6% in August. By fall, protein may decline to less than 4%.
Energy peaks in February and March at around 0.7 MCALlb of forage. This declines to 0.54 in May and approximately 0.4 MCAL by summer. This is a 40% decline from peak energy. Once forage reaches 0.4 MCAL, it stays at that level until fall greenup.
Based on these results, green and dry season supplements have been formulated. The main difference between the two is the addition of urea in the dry supplement to make up for low protein levels. The urea is being used to feed the microbes contained in the rumen. This keeps microbe populations high and enables the cow to get at all of the energy contained in the forage.
Objective: Determine the effects of controlled grazing on parasitation of cattle.
No work was accomplished in this area due to difficulty in finding an appropriate control group.
• Switching the calving season to spring matched animal demand to forage supply. This eliminated the need for substitute feeding with hay. This reduced both direct and overhead costs, improved gross margins on the cow-calf enterprise, and improved ranch profit.
• Matching animal demand with forage supply provided greater drought management flexibility.
• Stocking rate was increased by 53% by applying controlled grazing principles.
• Applying herd effect proved effective in eliminating Italian thistle populations.
Education and Outreach
• Project Open House, October 1996. 80 attended. Participants heard presentations on range nutrition and range economics. A project site tour followed.
• Project Update for UC Staff, April, 1997. We gave a project overview and demonstrated low-stress livestock handling techniques to 5 extension staff.
• California Grazing Academy, 3 were held during the life of the project. 103 participants attended this 3-day live-in program. Participants learned about pasture ecology and controlled grazing principles.
• California Grazing Academy for Resource Professionals. Two were held for 43 participants. These academies were designed for government agencies and featured additional sections on teaching and research.
• Project Open House, October 1997. 24 attended. Participants received a project overview and heard field presentations on pasture ecology, low-stress livestock handling, herd effect, body condition scoring and electric fencing.
• Developed project web site (www.foothill.net/~ringram). The site has received over 6400 hits. Almost 50 Informational articles are included.
• We conducted programs about the project in Oakdale, Half Moon Bay, Covelo, Petaluma, and Red Bluff to 160 total participants.
• We wrote and produced the California Grazing Academy Audiotape Series that consists of four programs on audiocassette and a workbook.
• The California based public television show "California Heartland" did a story on the project and the Grazing Academy in June, 1998.
• The Sacramento Bee and and Ag Alert carried feature stories on the Grazing Academy and the project.
• Project field days were held July and August, 1999 for 38 participants. Project results were shared and a body condition scoring exercise was conducted.
• The Fall, 1999 UC - SAREP newsletter, Sustainable Agriculture, had an in-depth article about the project.
Education and Outreach Outcomes
Areas needing additional study
It is important to point out that project data is based on two years of spring calving. We have shown it is possible to calve in the spring with no major problems. Several of the findings suggest some definite positive trends, however, they are nothing more than trends. More results are needed over more years. We don’t want to suggest everyone will be able to get a 100 percent conception rate or a 19-day calving season if they make the transition to spring calving.
Other questions that could be answered with more research include:
• How is proper body condition at calving determined? Is it a 6.5 or a 7 BSC or some other number?
• What is a better definition of “spring”? This project started calving April 1. Is it possible to calve earlier or should it be later?
• What needs to be done to heifers to improve conception rates? In the project, they were bred them at BCS 6 and still only generated an 80 percent conception rate.
• How far can a producer allow the cow’s body condition to drop? Is it possible to go down two BSC scores, one and half scores or some other figure?
• What paddock subdivision design is needed to be effective to ration dry feed until forage growth starts again? What happens if this doesn’t occur and the cows calve in the spring? Would similar results be achieved or would supplements be required? No hay was fed during this project.
It would be helpful to do this work on a larger scale over more years with a minimum of 100 cows on 1,000 acres over five years.