Controlled Grazing on Foothill Rangelands

Controlled Grazing on Foothill Rangelands

Summary

Objectives

1. Demonstrate controlled grazing on foothill/annual grassland and irrigated pasture
2. Demonstrate monitoring procedures to assess range condition and trend and livestock performance
3. Teach research based controlled grazing practices to livestock producers
4. Compare effects of controlled grazing to conventional grazing on livestock production and economic performance
5. Compare effects of controlled grazing to conventional grazing and livestock exclusion on plant communities
6. Determine effects of controlled grazing on trace mineral nutrition of cattle
7. Determine effects of controlled grazing on parasitism in cattle

Abstract

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 five Grazing Academies and three 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 regard to fencing, water development, and pumping with solar and ram pumps. Grazing planning was used to ensure rest periods of 30 to 45 days during fast growth and 90 to120 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 percent over historical levels. Plant 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 animals’ 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 percent 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 percent. Weaning rate was 92 percent for both years. Heifer conception rates were 80 percent. 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 spring calves kept to 11 months of age.

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 percent in February to less than four percent by October. Energy levels declined 40 percent between March and July and then remained relatively stable.

Dissemination of Results

In March 1997 we posted a web site on the Internet Developed project web site (www.foothill.net/~ringram). The site has received over 6400 hits. 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.

Four audio tape programs (California Grazing Academy Audio Tape Series) 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.

Potential Benefits or Impacts on Agriculture

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 percent by applying controlled grazing principles. Applying herd effect proved effective in eliminating Italian thistle populations.

Farmer Adoption and Direct Impact

We encourage the development of at least 16 paddocks per group of animals and advocate adjusting rest periods as plant growth rate, using the shortest graze periods possible (consistent with required rest), using high stock densities, and matching stocking rate with carrying capacity. We recommend using herd effect to rejuvenate range with moribund plants or capped soils and matching the livestock enterprise (species, age, size of animal, and season of use) to the environment supporting production. We suggest using low-stress livestock handling techniques and electric fences for livestock control in many situations. We strongly recommend the crunching of numbers to determine the economic and financial consequences of management decisions.

Future Recommendations or New Hypothesis

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 acknowledge that not 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 the following:
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.

This summary was prepared by the project coordinator for the 2000 reporting cycle.

Collaborators: