Final Report for OS03-011
Summary 1 describes the exploration of methods of gastro-intestinal parasites infection avoidance for grazing goats. Adult female goats were grazed on a sorghum sudangrass, BMR, annual hybrid during peak parasite infection periods. Goats were not dewormed or supplemented by grain during the grazing period. All goats recovered from lactation and gained significant weight during the grazing period. Goats in the study maintained acceptable body condition and were only mildly anemic. Fecal egg counts were held at tolerable levels without medication. Removing goats from parasite infected spring pastures to rapid growing summer annuals is an effective method of parasite avoidance. Seeding small blocks of high producing warm season annuals is cost effective and a nutritionally viable method of providing adequate nutrition while reducing parasite infections.
Summary 2 describes the possibility of using co-grazing, or mixed species grazing (goats and cows) as a means of reducing gastro-intestinal parasite in grazing goats. However, in this case, there were no treatment effects. Abnormally wet and mild weather conditions created excessive summer growth. Goat stocking rates were too low to accommodate the growth of tall fescue. End of rotation, residual dry matter mass was 1400 lbs DM/acre or 9 inches of pasture height. As a result, of the pasture height, few parasite infections occurred in 120 days of grazing. Modest pasture heights 4-5 inches may provide enough barrier protection for parasite infection avoidance.
Kentucky farmers have lost 75% of the burley tobacco crop due to production reduction (formerly valued at $6 Billion/year). Many small and limited resource tobacco farmers are hoping that meat goat production will replace a part of the primary farm income generated by four to five acres of tobacco. Presently five acres of burley tobacco would provide a farm family approximately $12,000 annually. This is a modest income but few agricultural alternatives can replace such an income. Reductions have caused small to moderate size family farm operators to looking for alternatives to tobacco in an effort to avoid total extinction. Presently meat goat production provides economic hope for small farmers in Kentucky and other southeastern states. However, most Kentucky producers (2600 producers and 70,000 goats in the state, USDA, Farm Service Agency, 2002 LCP status report) have been involved in the industry less than 2 years. Therefore producer education is a high priority for the Kentucky Cooperative Extension Service and is a priority for many southern eastern states.
Kentucky has many strong attributes that supports the production of meat goats. The state location is within one days drive to major goat meat markets and goat consuming populations. Secondly, forage and browse plant diversity is unsurpassed by any other state in the southeast. Furthermore, Kentucky’s Department of Agriculture (KDA) has distributed over 3 million dollars to Kentucky farmers for the purchase of meat goat seed stock, handling equipment and barn renovation. State Agricultural Diversity Programs are funded by tobacco company payments to tobacco producing states. In addition, KDA has designated two agricultural economists to assist Kentucky farmers in market meat goats.
Recent estimates indicate that 75% of the goat farms are not using forage resources effectively. Kentucky goat farmers are pen feeding expensive commercial feeds. Pen feeding is not a sustainable alternative due to the cost of feed and narrow margins for goat meat. Secondly, the animal is poorly suited for continuous concentrate feeding. Many metabolic problems are associated with high concentrate feeds. The majority of the research relating to this topic was done in the western U.S. and furthermore the work was dairy goat related. There is a need for research and simultaneous Extension education.
Kentucky’s number one goat health problem is internal parasites. Rampant herd infections together with drug resistance will hinder and possibly eliminate goat production in Kentucky if integrated methods of management are not incorporated into the present drug based protocol. Southwestern states environmental conditions mimic the natural habitat of the goat. These climates are characterized by low annul rain fall, sparse vegetation, and scrub-tree browse conditions. By comparison, Kentucky’s climate is classified as temperate having mild temperatures, abundant rainfall, and high humidity. Kentucky pastures experience long periods of wet foliage conditions which often linger throughout the year. Rain and humid conditions insure the productivity of Kentucky grasses, forbs and browse plants but at the same time increase the threat of internal parasite devastation of goat herds. By contrast, arid climates seen in the southwestern United States stop infections early in the year while Kentucky conditions foster larvae development through out most of the year. Nationally, the incidence of gastro-intestinal parasites and resulting development of parasite resistance to almost all anthelmintics is an obstacle to overall sustainability of small ruminant development.
Farmers, Extension Agents, Veterinarians and industry professionals must be made aware of integrated approaches to managing both nutrition and parasites. These are immediate industry concerns requiring localized information and Extension education. The above statement is supported by the voice of 400 Kentucky goat producers (20% of Kentucky producers) attending two SARE PDP funded Kentucky State University, Third Thursday, Sustainable Goat Production education events. These producers participated in the Lessoning Forms held March and October 2002. Likewise the SARE PDP Kentucky Funds sponsored the 2001 – 2002 Kentucky Agricultural Advancement Counsel meeting 2002, made up of one farmer representative and a County Extension Agent form each (120 counties) county in Kentucky. This prestigious group of agricultural leaders stated that the lack of education and research on goat production is a primary barrier to diversification for the post-tobacco agricultural community.
The primary objective of this work, Experiment 1, was to evaluate methods of gastro-intestinal parasite avoidance and to demonstrate these methods to producers, educators and veterinarians. Secondly to demonstrate to farmers the use of forages as a primary feed source for adult female goats. Third, validate through research, antidotal information that clams certain pasture management techniques are effective tools for reducing gastrointestinal parasites infection in goats.
All of the objectives were achieved through applied research, demonstration and related educational programs. Goat producers participated in the project and goat producers were informed by personal observation thus facilitated technology exchange via farmer to farmer contact.
The first study evaluated as well as demonstrated establishment methods, grazing management and benefits of a warm season annual forages. The forage component used in this study was a sorghum sudan grass hybrid with the brown mid-rib (BMR) gene (SSG-BMR). The SSG-BMR was seeded the first week of June, 2003 and grazing began July 7 and ended on September 17 resulting in a total grazing time of 70 days. The annual crop was seeded directly into a tall fescue pasture with a no-tillage drill. The tall fescue was sprayed with an herbicide, glyphosate, isopropylamine salt, (Roundup®) at a rate of 2 pints/acre prior to seeding. The seeding rate was 35 lbs of sorghum sudan seed per acre. Goats were maintained on pasture without shelter, water and mineral were provided.
Twenty four dry pregnant does were randomly allocated to 6 grazing paddocks. Four goats were placed in each paddock. The paddocks were divided by grazing blocks each randomly assigned a treatment of non-rotated or rotated. Blocks in rotation moved forward at 7 day intervals without access to the previously grazed sections. At the same time non-rotated blocks grazed continuously without rotation and maintained full accesses to the entire grazing area. The overall stocking rate was 9.6 head/acre. The rotationally grazed group were placed in a series of 5 paddocks each approximately 3600 ft2 with an in paddock stocking density of 48.2 head/acre. The non-rotated group had free access to 18,000 ft2 area.
All 24-goats on test were dewormed, weighted, body scored (1=very thin, 5=obese) and assessed for anemia by inspection of the lower eye membrane (1=not anemic, 3=very anemic). Internal parasite assessments were made by fecal egg counts (FECs) at deworming and prior to entry into the grazing study. The study was conducted during the peak gastro-intestinal parasite infection period (July 7 –September 17). All goats in the study were not dewormed or supplemented by grain for the entire 70 day period. Weighing, sampling and assessments were made on July 7, August 17 and September 17. Goats began grazing the SSH-BMR at 12-14 inches of height. Square foot samples were collected at 0, 7, 14 and 21 days post grazing. The forage was weighed dried and reweighed for determinations of percent dry matter. Furthermore, sub-samples of these cuttings were analyzed for nutrient content. SSH-BMR was sampled on September 17, 2004.
Experiments 2 used twenty four dry open does and they were randomly allocated into 6 grazing paddocks. Each paddock was determined to be 0.22 acres resulting in a stock density of 18-goats/acre. The goats were grazed for 21 days and rotated forward into a second, third and fourth set of 0.22 acre paddocks. Grazing duration was June 1 through September 28 for a total of 120 days of grazing. Goats were grazed together with 3 Holstein cows and the cows grazing 21 days behind the goats. Cows grazed behind goats on paddocks 1, 3 and 5 while paddocks 2, 4 and 6 were mowed to cow grazing height.
All goats were de-wormed, August 28 and returned to their assigned paddock grazing sequence. Goats grazed paddock regrowth for 28 days. Each goat was then evaluated for gastro-intestinal parasite eggs by (FEC) and assigned an anemia rating by FAMACHA methodology (color assessment of the lower eye membrane, ratings 1-5, 1=not anemic, 5=extremely anemic).
Experiment 1: All does grazed in rotation (R) and non-rotationally grazed (Non-R), gained weight, 28.1 lbs/70 days (0.40 lbs/day) for the Non-R and 23.3 lbs/70 days (0.33 lbs/day) for the R group. Weight gains in this study were not statistically different. Goats in both treatments maintained acceptable body condition (Non-R = 2.9, R = 2.5) for the 70 day grazing period. Does were observed to be only moderately anemic after 70 days without deworming. The color of the mucus membrane for Non-R was 1.6 and the R group was 1.7. Parasite egg counts at the end of the 70 day grazing period for the Non-R and R groups was 173.0 and 207.0 eggs/gram of feces (Direct count, Wisconsin Method). All 24 goats gave birth 1 and 2 months after removal from the plots. All goats kidded successfully and average 2.0 kids/female.
SSH-BMR grazing statistics indicate that the regrowth rate was 98.4 lbs of dry matter/day. The regrowth rate progress upward from day 0 to day 21 post grazing. Day 7 accumulated 39.3 lbs, day 14, 126.0 lbs and day 21, 129.3 lbs of dry matter for a total gain of 2716 lbs of dry matter in 21 day. The average, relative feed value (RFV) for the SSH-BMR was 76.5, likewise the average percent crude protein (CP), and total digestible nutrients (TDN) were 9.0% and 49.7% respectively. Furthermore, the average percentages of fiber content was divide by acid detergent fiber (ADF) was 40.0% and the neutral detergent fiber (NDF) was 70.2%.
Conclusions made from the observed data were that SSH-BMR is a suitable feed for dry pregnant does during early to late gestation. It appears that a CP level of 9.0% and TDN of 50% is quite adequate for pregnant does in the early and advanced stage of gestation. ADF percentages as high as 40% and NDF at 70% do not appear to be a limiting factor in providing good nutrition for does.
Secondly, as permanent pasture growth rates and nutrient content decline in mid- June, goat herds can be move off of permanent pastures onto highly productive patches of warm season annual crops. In addition, while goats grazing summer annuals, permanent pastures have time for dry matter regrowth and reduction of gastrointestinal parasite larvae numbers residing on blades of grass and in manure piles. SSH-BMR provides an up-right growing plant that allows grazing goats the opportunity to avoid intestinal parasite infection by grazing above the parasite infection zone.
SSH-BMR is a highly productive warm season annual that integrates well with cool seasons perennial forages such as tall fescue and orchardgrass. SSH-BMR is conducive to higher stocking rates when compared to conventional cool season pastures. Stocking rates can be increase by at least 4 to 5 times that of cool season pastures. This annual forage has a rapid regrowth rate of approximately 100 lbs of dry matter/acre/day. This gives an accumulation of 3000 lbs of dry matter in three weeks of rest.
The Non-R group appeared to thrive as well as the R group. This may be attributed to the under stocking of available forage resources. The stocking rate was not high enough to adequately control the growth of the SSH-BMR. Grazing goats were highly selective in diet choices. The stocking rate for the non-R sections should have been at least twice the 9.6 goats/acre.
A persistent problem observed in the non-R group was continuous consumption of the new growth. There was no net accumulation of regrowth in plots grazed without rotation. Goats preferred the new growth from previously grazed areas to the maturing stand of SSH-BMR ahead of them. Furthermore, Non-R goats preferred to stay in the previously grazed area over entering taller growth foraging areas. Similar behavior was observed in later demonstrations. This social effect was not seen in the rotational group. The avoidance situation was made less severe, in later demonstrations by cutting walking strips (3 ft wide) down the center of the foraging area or along fence lines defining the boundaries of the foraging area. By observation, goats prefer a 360º field of view over entering tall forage with a high degree of view obstruction.
Finally, if grazing goats are not forced to move within a single grazing perimeter, they socialize between grazing events at one location in the field. The social location was in proximity to the initial starting point of grazing. These types of herd gathering within a single location may be an ideal site for parasite egg unloading and accumulation of parasite eggs and larva. As goats consume ground sprout regrowth and weed species close to the soil line, goats may become parasitized. This social activity may have increased parasite loads in the Non-R group. Egg counts at the end of 70 day period were within treatment range but the goats were not heavily parasitized or severely anemic.
Similarly, goats grazing in rotation may have become infected with internal parasites when DM was allowed to become limiting within a paddock. In such conditions goats were observed to graze weeds and annual grasses, as ground sprouts, close to the soil line. An overall residual grazing height must be selected an observed if effective parasite avoidance is to be successfully achieved. Likewise, the egg load indicated a need for treatment but the goats were not extremely parasitized or anemic.
In summary, grazing SSH-BMR in midseason is an effective means of avoiding parasite infections. However, observations made during this study should forewarn producers regarding over-grazing of warm season annuals particularly in rotational systems. If goat numbers are concentrated, as in this study, and the tall forage becomes limiting, the goats will graze low to the ground on what ever is available to them. Pastures should be managed with a high enough stocking rate to reduce underutilization of forage. Little to no regrowth will be accumulated if a 2 – 3 week rest period is not given. Move animals off the SSH-BMR when approximately 25% of the foliage remains on the plant. Set residence time, time spent grazing a paddock at 7 to 10 days. Provide 3 – 4 grazing paddock and allow a 14 - 21 day rest period. Companion grazers such as cows and horses can be used to control over growth conditions. Finally, under good growing condition, dedicate 1/4 -1/3 acre of SSH-BMR for each pasture acre or for every 5 adult goats.
Experiment 2: There was no treatment effects in experiment 2 related to type of grazing management. Goats in co-grazing (Co-G) management, grazing behind cows were similar to goats grazing (G) behind mechanical mowing. The average weigh of Co-G goats was 96 lbs and G goats 97 lbs at the onset of the June 04 grazing season The September 28 weights were similar for Co-G goats and G goats at 97 lbs and 99 lbs respectively. Likewise, body condition score (BCS) increased slightly from June 04 to July 04 but the average BCS for Co-G goats and G goats was 1.9 for the 120 day grazing period. FAMACHA readings averaged 3.1 for both groups. Fecal egg counts averaged 8.7 and 42.0 eggs/gram of fecal material for the Co-G and G groups. Goats from both treatments contracted low levels of parasite infections and less than 1/3 of the goat herd was de-wormed during the study. Deworming decisions were made on FAMACHA readings for each goat in the study.
A review of the weather conditions for June-September, may explain why there were few parasite infections for the 120 day study. Above normal temperatures and precipitation prevailed in the spring and summer of 2004. Rainfall deviations from normal was seen in June, +0.06 inches; July, +0.99 inches; August, +0.71 inches; and September, +0.76 inches (UKAWC-2005). These conditions were favorable for parasite development and infection however, parasitize infections did not reach critical levels.
Furthermore, these same weather conditions also created favorable pasture growth conditions. The tall fescue did not go into dormancy and rapid pasture growth continued the entire grazing season. Goats continued to graze in paddocks for 21-days with a stocking density of 18 goats/acre, yet few infections occurred.
The logical explanation for this phenomenon relates perhaps to pasture height and grazing height. Pasture densities were determined by rising plate before and after grazing. Pasture residuals were determined to be 1400 of dry matter/acre at the end of each grazing period. Estimates of pasture heights were made based on the assumption that 1 acre inch of tall fescue has 150 lbs of dry matter/acre (Ball, D.M., Hoveland C.S. and Lacefield G.D., Forage Crop Pocket Guide). Therefore pasture residual height was estimated to be approximately 9.3 inches of height. This would indicate that goats grazed the tall fescue tops and very little grazing within the canopy. Turn-in heights were determined to average 2500 lbs of dry matter and 16.6 inches of height indicating an overall pasture disappearance of 1300 lbs of dry matter/acre. This number does not reflect regrowth during the grazing period.
These data may confirm a recommendation, not initially considered in this study, which states that maintaining grazing heights, above a theoretical infection zone, estimated to be at 3 – 4 inches above the soil line is perhaps an effective means of parasite avoidance. In light of practical pasture management, pasture residuals should not be as high as 1400 lbs. High forage residuals indicate poor utilization and low nutritional continent. Ideal residuals would be in the 600 to 800 lbs or 5 - 6 inches of residual height. However, in this case it appears that the grazing goats avoided infection by grazing well above the infection zone.
These grazing and novel pasture management techniques were presented at the state, regional and national levels. A state wide meeting entitled the 3rd Annual Kentucky Grazing Conference, held in Lexington, KY was attended by 125 farmers and industry leaders from sever surrounding states. Secondly, a similar presentation was made at the Heart of American Grazing Conference, (HOAGC), held in Evansville, IN. The HOAGC is supported by 7 states which include universities and USDA organizations. The HOAGC conference was attended by an excess of 500 farmers and participants.
Secondly, and extension TV program was filmed on site when the grazing goats on the SSH-BMR. This clip was shown for a month in Kentucky and nationally on a farm news report TV program. In addition, 3 parasite management train-the-trainers were conducted for county extension agents in Kentucky. Topics covered were parasite egg identification, FAMACHA and parasite avoidance through pasture management techniques.
The Kentucky Goat Producer’s News Letter was also use as a means of distributing grazing information. The newsletter is sent to 6 states and is available on the U.K., Animal and Food Sciences web site: www.uky.edu/Ag/AnimalSciences/goats/goat.html,
and the www.uky.edu/Ag/AnimalSciences/goats/presentations/goatpresentations.html site has a web based slide show relating basic elements of parasite management through pasture management. Gastro-Intestinal Parasite Survival Kit for Goats was published in a regional farm news magazine. The topic was later adopted by Intervet as a client educational guide for sheep and goat farmers.
PowerPoint presentations were presented to hundreds of farmers and industry people. PowerPoint’s include Goat Friendly Pasture Series, 2006 Forage Presentation, Parasite Avoidance, Parasite Management Survival Kit, Pulaski Co. Grazing Project, and Raising Goats on a Few Acres (presented at the national meeting of the American Boer Goat Association).
The impact of this study has had a wide and expanding effect on many producers in Kentucky, West Virginia, Tennessee and Indiana. It has taken approximately three years for producers to begin adoption of adding a separate grazing block to their pasture base. We have observe at least 12 individuals in Kentucky who are currently using SSH as a mid-season forage specie as wells 1 in Tennessee, 1 in West Virginia and 2 in Indiana. Furthermore 3 seed companies are using SSH in summer annual goat mixes in their farmer advertisements. In addition, we have 18 farmers in Kentucky who are using rotation and pasture height management as a means of parasite avoidance. Some producers are using pasture sticks to measure pasture height. Adoption of new or different technology is slow; however the current drug resistance situation necessitates rapid adoption.
Areas needing additional study
These methods described above show promise as viable parasite management methods. However, a great deal of work is need in refining management protocols that are both practical for farmers and effective means of parasite abatement. Secondly, successful co-grazing work is needed and if promise is shown, add co-grazing to the arsenal of management procedures.