Nutrient optimization for sustainable goat production systems in the southeastern U.S.

Nutrient optimization for sustainable goat production systems in the southeastern U.S.

Summary

Feed cost is the major variable cost for meat goat production. Goats raised for meat need high quality feed in most situations and require an optimum balance of many different nutrients to achieve maximum profit potential. Therefore, profitable meat goat production can be only achieved by optimizing the use of high quality forage and browse, and minimizing the use of expensive commercial feeds. This can be achieved by developing a year-round forage program allowing for as much grazing as possible throughout the year. For this project, six different forage combination (grasses and legumes) were planted in September of 2009 for winter grazing. Twelve paddocks, 0.5 acre each were planted, where two paddocks represented each grass/legume combination. For the first year, forage samples were collected monthly starting from February through May of 2010. Multi-culture forage systems had similar forage dry matter (DM) production for grasses and grasses in combination with legumes for the month of February. However, forage DM production in March was significantly higher for wheat and rye (WR) + berseem clover (BC) compared with other combination followed by WR + Australian pea (AP) + hairy vetch (HV) + BC , WR + AP+ HV, WR+ HV, WR + AP, and WR combination; P < 0.01). In April 2010, forage DM production reached maximum, but lower in nutrients composition. Dry matter production for WR or WR + HV (P < 0.01) was lower than other combination groups in April 2010 (Figure 1). Botanical legume composition was higher in multi-cultural forage systems (> 3 species) than mono- or two-legume forages combination. The chemical composition of forages; crude protein (CP), soluble protein, neutral detergent fiber (NDF), ether extract, in vitro dry matter digestibility (IVDMD), Ca, P, Mg, S, Na, Fe, Cu, Mn, nitrate, non fibrous carbohydrates (NFC), and estimate of net energy (NE) for lactation, remained similar with varying species of grass/legume forage combination, but acid detergent fiber (ADF), ash, K, Cl, Zn, net energy for maintenance (NEm), and net energy for gain (NEg) were varied among multi-forage combination (P < 0.05-0.001). Forage CP content in all treatment groups was highest in March than February and April, but NDF content continuously increased with time. The data indicated that when grasses are combined with at least one legume had higher DM production; wheat and rye in combination of berseem clover had highest DM yield; and plant maturity and time under Alabama filed condition is an important factor affecting the forage quality and quantity.

Objectives/Performance Targets

1. 1) Determine pasture quality changes using multi-culture grasses, and grasses in combination with legumes;

   2) Determine animal health, performance and carcass quality of goats when browse is incorporated in the feeding system and when grazing multi-culture grasses, and grasses in combination with legumes;

   3) Determine soil quality changes using multi-culture grasses, and grasses in combination with legumes;

   4) Identify and assess economic characteristics and optimum economic return of different goat production (grazing/browsing) systems;

   5) Evaluate adaptability (on an experiment station with goats) and demonstrate applicability (on three small farms) of an integrated year round forage system using commercial goats, pure bred goats, and goat co-foraging with cattle.

   For this report Objectives 1, 2, and 3 will be addressed

Accomplishments/Milestones

Objective 1. Determine pasture quality changes using multi-culture grasses, and grasses in combination with legumes

Winter Grazing

For this objective, 6 forage combination (grasses/legumes), for winter gazing were planted in duplicates on 12 pasture paddocks of 0.5 acres each. Seedbeds were prepared in September of 2009, according to the recommendations with proper amounts of seeds, per acre, for respective forages and were planted in October. Six different forage combination were: (1) annual rye grass/wheat (RW), (2) RW + Berseem clover (BC), (3) RW + Australian pea (AP), (4) RW + Hairy vetch (HV), (5) RW + AP + HV, and (6) RW + HV + AP + BC (Table 1).

Summer Grazing

For summer grazing, six different forage combination has been planted including (1) bermudagrass (BG), (2) sericea lespedeza (SL), (3) BG + SL, (4) BG+ soybeans (SB), (5) BG+ brown top millet (BTM), (6) BG+ BTM + SB. Seedbeds were prepared in October 2009 for SL and April for the rest of the forage combination.

All the forages for winter grazing were newly sown with no-till drill methods after bush-hog (Figure 2 a). The area for each forage combination (2 rep x ½ acre) was planted in October 26, 2009 and April 15, 2010 for winter and summer forages, respectively. Seeds were drilled at the different seeding rate (Table 1). After forages emerged for winter and summer forages, respectively, fertilizer (16-16-16; K:P:N, respectively) was applied at 500 lbs/ac in November 19, 2009 and May 15, 2010, respectively. However, due to the severe drought in summer of 2010, and sandy soils at the Tuskegee University George Washington Carver Agricultural Experiment Station, summer forages subsequently died (Figure 1b), thus providing no summer data. We will re-sown and grazed in 2011. We have plans to invest in water irrigation system for summer forage in 2011 to accomplish our objectives.

To accomplish goals for this project Tuskegee University has invested (supported) $35,000 for primitive fencing (Figure 1 a) of 12 acres of pastureland and another $16,000 was invested for cross fencing of 24 ½ acre paddocks. SARE project and NRCS project (PI’s another project) together had to invest the rest of the funding ($22,000) for cross-fencing due to budget cuts (Figure 1 b). First winter 2009-2010 and summer forages (2010) could not be grazed; however, data on forage production for winter grazing are reported here. As indicated above, due to sever drought in Macon County and throughout the southeast, summer forages did not survive in our sandy soils.

Forage mass (kg DM/ha), botanical composition and forage chemical composition were measured on February, March and April 2010. On each occasion four random quadrate per paddock were cut using a hand-clipper for biomass. The forage samples were then oven-dried at 90 degree C for 18 h, and weighed. For laboratory analysis, four quadrates of herbage on offer were cut to ground level from each paddock. Samples were combined for each paddock, mixed, and divided, with the first part used for botanical composition assessments and the second part for chemical analysis.

Statistical analysis

All data were analyzed as repeated measure with production system included in the model as a fixed effect using the Proc GLM procedure of SAS (SAS Inst. Inc., Carry, NC). Differences among means, for all analysis, were determined by least square means procedure with the protected F-test (P < 0.05).

Results

Forage biomass changes

The benefit of using multiple species on the same pasture comes from the fact that different animals have different plant preferences. Multi-culture forage dry matter (DM) production (Figures 3 and 4) in February 2010 was similar between grasses and grasses in combination with legumes. However, forage DM production in March was significantly different in the following order: Wheat and rye (WR) + Berseem clover (BC) > WR + Australian pea (AP) + hairy vetch (HP) + BC > WR + AP+ HV > WR+ HV > WR + AP > WR combination; P < 0.01). In April, forage DM production was higher, but lower in nutrient contents. Average forage DM production was lower (P < 0.01) for WR or WR + HV than other combination group. Botanical legume composition was higher in multi-cultural forage system (>3 species) than grasses- or two-grass/ legume combination (Figure 5).

Forage chemical composition

Forage chemical composition of multi-cultural forage system is presented in Tables 2. The crude protein (CP), soluble protein, NDF, Oil, IVDMD, Ca, P, Mg, S, Na, Fe, Cu, Mn, nitrate, NFC, and NEl remained similar with varying species of legume forage combination, but ADF, ash, K, Cl, Zn, NEm, and NEg were varied among multi-forages combination (P < 0.05-0.001).

There was no significant interaction between sampling time (Feb, Mar and April) x multi-forage combination for CP, ADF, oil, IVDMD, Ca, Mg, S, Na, Fe, Cu, Mn, NFC, and NEl. However, there was a forage sampling time x multi-forage combination interaction (P<0.05-0.01) for NDF, P, K, Cl, Zn, and NEm (Figure 6). Forage CP content was higher in March than February and April (Table 3), but DM and NDF content continuously increased with time. The data indicated that plant maturity and forage growth are important factors affecting forage quality and forage DM production.

Forage total CP, P, and K biomass output

Total CP output was calculated by multiplying average DM output per month by average CP %. Total CP output was highest for RW+BC+AP+HV and lowest for RW+HV and RW combination. RW in combination with BC or AP improved CP output by 10 and 3% respectively; however, addition of HV decreased the CP output by 8%. Two-legume combination, RW+AP+HV and three-legume combination, RW+AP+HV+BC improved CP output by 19 and 30% respectively. If soil N and organic matter improve accordingly, it will reduce future N application.
Total P output was highest for three-legume combination and lowest for RW+AP. Three legume combination improved P output by 14% over RW alone. One legume combination, RW+BC had higher P output than all other counterparts and two-legume combination; However, RW alone had higher P output than all one or two legume combination.

Total K output was higher for RW, RW+HV, and RW+ three-legume combination than other two or one legume combination.

Forage nutrient output and animal requirement

Average crude protein content of pasture forages (16.7 to 18.3%) meets and exceeds requirement for meat goats and dairy goats. Average in vitro digestible matter as indicated by IVDMD (72 to 74.2%) is above 67% minimum requirement for ruminants and will provide optimum TDN for meat or dairy goats. Levels of ADF ranging from 22.2 to 23.8 and NDF ranging from 40.1 to 40.8 are ideal for growing and lactating goats. The ratio between Ca:P is optimum at 2:1 for ruminants. Two legume combination and RW+AP provided closer to optimum ratios of 1.74 and 1.67, respectively approaching ideal level. All forages are deficient in majority of macro and micro minerals especially NA, Cu and Se; therefore, mineral supplementation is recommended when goats grazing winter or summer grasses.

2) Determine animal health, performance and carcass quality of goats when browse is incorporated in the feeding system and when grazing multi-culture grasses, and grasses in combination with legumes;

As mentioned above we could not gather animal data because of budget cuts and delays in fencing. However, fencing for winter grazing is ready now. All pastures are planted similar to last year and we are waiting for rain. Pastures will be stocked with at least 4 animals each and animals will be continuously graze different paddocks. Results will be included in the next progress report.

3) Determine soil quality changes using multi-culture grasses, and grasses in combination with legumes;
Preparations are underway for this project. Soil samples for 6 winter pastures in duplicates were collected at the end of season (May 10). Results will be reported in the next progress report.

4) Identify and assess economic characteristics and optimum economic return of different goat production (grazing/browsing) systems.

More data is needed to assess optimum economic returns of multi-culture pasture (grass and legumes) vs grass only. Total crude protein output from each treatment combination will be calculated. This data along with soil nitrogen and organic matter improvement will be factored in determining optimum forage system. Animal performance data as well as length of pasturing will also affect profitability and economic feasibility of the system.

5) Evaluate adaptability on an experiment station with goats and demonstrate applicability (on three small farms) an integrated year round forage system using commercial goats, pure bred goats, and goat co-foraging with cattle.

For this objective two producers (Mr. Bennie Simmons; Dallas Co. AL and Ms. Sandra Simon; Talladega Co. AL; Fig. 7) have been identified and are currently working with our team. We already have purchased multi-forage seeds and are ready for planting for winter forages 2010.

Problems Encountered

Project officially started July 1, 2009, when funding became available for the project. A technical assistant was hired and plant seeds and fertilizer for winter forages were ordered and forages were planted in 6 ½ acre paddocks in duplicate by October 2010.
First winter 2009-2010 and summer forages (2010) could not be grazed because of lack of fencing; however, data on forage production for winter forages are reported here. Due to sever budget cuts cross fencing was delayed for winter of 2009-2010 and summer of 2010.
We have been experiencing drought frequently in this area and this necessitates development of irrigated pastures, if grazing is recommended for summer. The cost of irrigation facility should be factored in the cost and benefits of such a system. We will try again in 2011 and 2012 for summer grazing and if needed economics of establishing irrigated pastures will be provided.

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• Table 2
• Table 3
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• Table 1

Impacts and Contributions/Outcomes

We feel using proper forages for winter grazing followed by summer forages can provide for year-round foraging. However, combination of forages used for grazing should be selected to optimize animal performance, enhance the soil property and reduce methane or ammonia emission from feces while reducing dependency on petrochemical fertilizer. Fencing is a major expense when encouraging farmers to divide pastures and plant winter forages for grazing. However, the next limiting factor is the price of fertilizer. We are hoping that combining legume forages with grasses will increase protein output as well as restore N in soil, thus reducing dependency on petroleum-based fertilizer. We also hope some of these combination may reduce methane and ammonia emission from animal feces for more sustainable environment.

Collaborators: