Sustainable Year-Round Forage System for Goat Production in the Southern USA
Series of experiments were conducted to evaluate carrying capacity or stocking rates of mimosa fields, when rotationally browsed, and Marshall ryegrass pasture, when continuously grazed by goats. Samples and data from prior experiments were analyzed. It appeared that 4 goats/acre was sufficient for mimosa browse system and based on data of animal performance on Marshall ryegrass, 8-11 goats/acre were superior to 14 or 17 goats /acre. Carcass characteristics of goats raised on different feeding systems are also summarized and reported.
- Study the pattern of foliage removal from mimosa by goats, and determine the optimal
degree and frequency of defoliation.
Establish the optimal stocking rates and associated animal weight gain for goats when
feeding on mimosa in summer, and annual ryegrass in winter.
Determine whether mimosa has any anthelmintic effect when browsed by goats.
Determine carcass quality and if there is a consumer preference for meat from browse-
Compare productivity of goats on ryegrass with that of cattle.
Evaluate (on an experiment station) and demonstrate (on two small farms) an
integrated year-round forage system of mimosa in summer and annual ryegrass in winter for goat production by limited resource farmers.
Results obtained for this objective in prior years have been applied for 2004 browsing study. Altering canopy structure by pruning stems to about 2 ft and allowing only limited re-growth prior to defoliation is more effective in achieving more uniform partial de-foliation. Due to goat market structure, 2004 browsing study started first week of August and ended at mid October; however, goats could be introduced to mimosa browse 4-6 weeks earlier. Forth of July is a major holiday for goat sale, thus, it is hard to find stocker goats and goat prices are at their prime during this time.
Mimosa Study (Summer Browse):
Mimosa paddocks were prepared as described in prior report. Results of goat production on mimosa browse are as follows:
Average daily gain on mimosa for goats is about 80 g/day when goats are browsing rotationally at 20 goats/5 acres. Mimosa appears more nutritious, indicated by chemical analysis, rather than animal performance The chemical composition of mimosa warrants higher gains; however, either an imbalance in energy to protein ratio or presence of compounds such as condense tannins may be the hindering factor. Some of our mimosa samples have been sent to University of California-Davis for further analysis. More research is needed to formulate appropriate supplement for goats on mimosa browse.
Market data for 20 bucks on mimosa browse indicates that $/lb ranged from $1.2 to $1.25 for choice to prime goats. As indicated the difference in the price of prime goat or just choice is not significant and does not warrant effort for producing better conditioned goats in Alabama.
Intake study and carcass data are currently being evaluated and will be reported in the final report.
Experiment 2 and 3, December 15- 2003, 2004- April 2003, 2004:
These experiments were conducted to determine the optimum stocking rate of goats grazing on annual Marshall ryegrass. Four approximately one-acre paddocks were prepared and 8, 11, 14 and 17 animals (buck kids) were randomly assigned to these paddocks and start grazing on December 15, 2003 and again 2004. Average daily gains were 55, 71, 135 and 153 g/day for stocking rates of 17, 14, 11 and 8 goats/acre, respectively; however, disc meter readings were 3, 4, 5 and 5.5 inches, respectively. Based on the results of these experiments stocking rates at 8-11 goats/acre are appropriate and there is a direct relationship between average daily gain of goats and disc meter reading for ryegrass pastures.
This objective was accomplished and results were reported in 2004 annual report.
Experiments were conducted to evaluate animal performance and carcass quality for goat kids raised on different feeding systems, grazing on bahiagrass pasture, browsing mimosa or grain fed indoors. Some information on carcass quality are reported here and more data is currently being analyzed and will be reported in final report
The effect of production systems on growth and carcass traits of semi purebred (87.5%) or crossbred (50.0%) castrated Boer kids was determined. Twenty four semi purebred (initial BW 23.15 + 0.74 kg) and twenty one crossbred (initial BW 18.99 + 0.79 kg) kids were used. Treatments consisted of: 1) a concentrate grain diet (CONC) containing 40% dairy pellets (CP 15.5%, NDF 24% DM basis), 40% soybean hulls (CP 13%, NDF 58% DM basis), and 20% bermudagrass hay (CP 11%, NDF 66% DM basis); 2) bahaigrass pasture (BG) (CP 8%, NDF 70% DM basis) supplemented with 150g/hd/d dairy pellets; 3) Mimosa browse (MB) (CP 21%, NDF 38% DM basis) supplemented with 100g/hd/d cracked corn (CP 9%, NDF 28% DM basis). The growth period consisted of 14 wk. Animals were slaughtered when a final BW of 35.0 + 5.0 kg was obtained or when the forage season ended. At 48 h postmortem, various yield measurements were collected. There were no breed-type differences after adjusting for initial weight, harvest weight or days to harvest using analysis of covariance. Semi pure and crossbred Boer kids receiving the BG treatment had lower ADG (46.2 g/d + 5.33; P < 0.0001) than goats receiving the MB treatment (80.8 g/d + 5.28) and required more days on feed to reach harvest end points. Goats receiving the CONC treatment exhibited the highest ADG (141.3 g/d + 5.37 ;P < 0.0001) and reached harvest end point two to four wk faster than BG or MB treatments. Goats from the CONC treatment had heavier hot carcass and cold carcass weights (P < 0.05) with higher dressing and shrinkage percentages (P 0.10) in kidney pelvic fat, back fat, adjusted fat thickness, bone weight, percent lean weight or carcass selection grade between treatment groups. Carcasses from the CONC and MB groups were heavier with larger LM area (P < 0.05) than carcasses of the BG group. These results indicated that feeding Boer kids with a CONC diet produced heavier carcasses and larger LM area and goats on browse with less input performed superior than goats receiving concentrate on BG.
More data on this objective will be summarized in final report.
Two independent producers have been identified. We have started preliminary preparations of the farms. Strength and weaknesses have been identified and recommendations have been given. We are currently working with these producers and their farms are used as demonstration sites.
A video is under preparation and will be completed and will be submitted as a part of outreach package for this project.
First buck sale and show was conducted in conjunction with Tuskegee University Goat Day. More than 5 bucks from annual Marshal ryegrass study were sold. This marked the first such an event for more than 20 years on Tuskegee University campus.
A workshop on rygrass pasture will be conducted on April 30, and another workshop on summer grazing and browse will be conducted this summer. Studies such as grazing and browsing take more than 2-3 years to show results. Projects with limited time frame do not allow for the results to be confirmed.
Impacts and Contributions/Outcomes
A combination of mimosa in the summer and annual Marshall ryegrass in the winter is likely to provide an outstanding year-round forage system for goat production by limited resource farmers in the southern US. However, more data is needed to develop the best management practices for this system, and to clearly demonstrate its superiority over typical systems currently being used. Current data confirmed that mimosa provides an excellent alternative feed for summer; however, mimosa appears more nutritious, indicated by chemical analysis, rather than animal performance. The chemical composition of mimosa warrants higher gains; however, either an imbalance in energy to protein ratio or presence of compounds such as condense tannins may be the hindering factor. Annual ryegrass as winter pasture for goats is very promising; however, 8-11 goats per acre maybe sufficient, for maximum yield, and requires intensive management.
Animal and Poultry Sciences
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Agronomy and Soils
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Animal and Dairy Sciences
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