Sustainable goat farming: Pasture enhancement and diet selection by goats

Sustainable goat farming: Pasture enhancement and diet selection by goats

Summary

Meat-goat farming is becoming popular to many small-scale farmers in Alabama. However, making this business sustainable is a challenge, especially with the existing poor pastures and grazing practices. Not much information is available on suitable forages for improving goat pastures and managing them sustainably. The objectives of this study were 1) to improve the existing goat pastures by incorporating selected cool-season forages, and 2) to determine goats’ preference for the selected forages. The study was conducted in Selma and Phenix City, Alabama as a randomized complete block with three replications in each site. Five treatments: mixture of Marshall ryegrass (Lolium multiforum) and one of the selected cool-season legumes (arrowleaf clover, Trifolium vesiculosum; berseem clover, Trifolium alexandrinum; crimson clover, Trifolium incarnatum; hairy vetch, Vicia villosa; and winter peas, Pisum sativum) and a control of sole Marshall ryegrass plantings were tested. Pastures were managed with rotational grazing. Forage biomass before grazing, and forage height both before and after grazing were measured. Marshall ryegrass-crimson clover and Marshall ryegrass-hairy vetch mixtures were most productive among the treatments. All selected legumes and Marshall ryegrass were readily eaten by goats from the very beginning, except winter peas, which was consumed well from the second grazing. The first-year study results show that 1) crimson clover and hairy vetch are the most competitive legumes to be planted with Marshall ryegrass for enhancing goat winter pastures although goats would readily consume any of the selected forages, and 2) the selected forages can be managed well with rotational grazing. More information on the study will be obtained from the second-year results. Findings of this research will be very useful to goat producers and Extension personnel for improving and managing goat pastures, and eventually promoting the sustainability of goat farming.

Keywords: Marshall ryegrass, arrowleaf clover, berseem clover, crimson clover, hairy vetch, rotational grazing, winter peas

Objectives/Performance Targets

1. 1) To improve the existing goat pastures by incorporating selected cool-season forages
   2) To determine goats’ preference for the selected forages

Accomplishments/Milestones

This study was conducted in the farms of two cooperator farmers: Mr. Gregory Scott from Selma and Mr. Nimrod Stephens from Phenix City, Alabama. Each site had ‘sandy’ and ‘loams and light clays’ type of soil. Soil samples from each site were tested for necessary liming and fertilization, and lime and fertilizers were applied based on the soil test recommendations for the selected forages. Lime was applied three months before planting, and fertilizers were applied at the time of planting. The study was set up as a randomized complete block design with three replications in each site. Each replication contained six equal strips, where the selected treatments and a control were randomly allocated. Five treatments: mixtures of Marshall ryegrass (Lolium multiforum) and one of the selected cool-season legumes (arrowleaf clover, Trifolium vesiculosum; berseem clover, Trifolium alexandrinum; crimson clover, Trifolium incarnatum; hairy vetch, Vicia villosa; and winter peas, Pisum sativum) and a control of sole Marshall ryegrass were tested in the study. Seed rate for all grass-legume mixtures contained 60 percent grass and 40 percent legume seeds. Perimeter and cross fencings were established to develop each replication as a paddock for rotational grazing. Continuous water supply was made available to each paddock for the grazing goats. When forages were well established and reached the grazing height, three biomass samples from each strip were clipped to 5 cm within 0.25 m2 quadrats before each rotational grazing began in each replication throughout the 2012 cool-season growing period. After sample collection, goats were allowed to graze the paddocks rotationally. Goats used in this study were mostly Boar, and few Kikos and Nubians in Selma, and Boer and crosses of Boer, Kiko, or Spanish in Phenix City. Forage heights both before and after grazing were measured. During the cool-season growing period, samples were collected three times (sampling sequence 1-3) in Selma and twice in Phenix City study site. Forage biomass data were analyzed using the Mixed model (SAS 9.3) with block as ‘random’ and sampling sequence as ‘repeated’ factors without specifying any covariance structure as this produced the best ‘fit statistics’ for the data set (Littell et al. 2006). Treatment and sampling sequence were the main sources of variation. Alpha probability level for rejection of the H0 (null hypotheses) in favor of Ha (alternative hypotheses) was set at 0.05. Following was the general model used to analyze the forage biomass data.

Where,
Yijk = value of an observation taken at the kth sampling date in jth block and ith treatment
µ = grand mean
?i = main effect of ith treatment, i = 1, 2, ….., 6
?k = main effect of kth sampling sequence, k = 1, 2, 3
(??)ik = interaction effect of ith treatment and kth sampling sequence
eijk = error associated with the kth sampling sequence in jth block and ith treatment

Impacts and Contributions/Outcomes

Objective1. To improve the existing goat pasture by incorporating selected cool-season forages

1. Selma study site
Average grass, legume, and total forage dry matter production in Selma study site is presented in Table 1. There was no effect of treatment, sampling sequence, or treatment and sampling sequence interaction on grass dry matter production. However, all these effects were present for both legume and total dry matter production (Tables 1 and 2). Average legume dry matter production was the highest for crimson clover-Marshall ryegrass and hairy vetch- Marshall ryegrass treatments (Table 1). In Sampling Sequence 2, crimson clover-Marshall ryegrass, hairy vetch-Marshall ryegrass, and winter peas-Marshall ryegrass produced higher legume dry matter compared to other treatments. However, in Sampling Sequence 3, crimson clover-Marshall ryegrass mixture produced the highest legume dry matter among the treatments. Like legume dry matter, average total forage dry matter was the highest for crimson clover-Marshall ryegrass and hairy vetch-Marshall ryegrass mixtures among the treatments. Differences among treatments on total forage dry matter occurred in Sampling Sequence 2 with winter peas-Marshall ryegrass and hairy vetch-Marshall ryegrass treatments performing better than few other treatments and in Sampling Sequence 3 with crimson clover-Marshall ryegrass and hairy vetch-Marshall ryegrass treatments excelling few other treatments.

2. Phenix City study site
Unlike in Selma, this site did not have a good stand of legumes as the cooperator farmer could not stock enough goats to consume tall-grown forages for avoiding shading to the legume seedlings at the very first grazing. So, no significant effect of treatment or interaction effect of treatment and sampling sequence was evident on forage dry matter production. Average forage dry matter production during the 2012 cool-season growing period in this site is shown in Fig. 1.

Objective 2. To determine goats’ preference for the selected forages

1. Selma study site
Goats readily consumed forages from all treatments throughout the cool-season grazing period, except winter peas at the very first grazing. From the second grazing, winter peas were also readily eaten by goats. It can be seen in Table 3 that both grass and legume heights after grazing were significantly reduced compared to the heights before grazing for all treatments. Among the treatments, grass height before grazing was the highest for hairy vetch-Marshall ryegrass, and legume height was highest for winter peas-Marshall ryegrass and hairy vetch-Marshall ryegrass mixtures. Both grass and legume heights after grazing were the highest for winter peas-Marshall ryegrass among the treatments. This result could be because of the avoidance of winter peas by goats at the very first grazing.

2. Phenix City study site
Unlike in Selma, this site had scarce legumes. So, only the average forage height before and after grazing has been presented (Table 4). The grazing pattern remained the same as in Selma with goats avoiding winter peas at the very first exposure, and consuming it well from the second exposure. All other legumes and Marshall ryegrass were eaten well from the very beginning. Forage height for all treatments was significantly reduced after grazing.

Conclusions
Results from the Selma site show that crimson clover-Marshall ryegrass and hairy vetch-Marshall ryegrass mixtures are the most productive among the selected treatments under the given soil, environmental, and management conditions. Grazing study from both study sites indicates that any mixture of Marshall ryegrass and selected legumes is readily consumed by goats, except winter peas for which goats require some time to get used to it. More information on the productivity of the selected treatments and goats’ preference for these treatments will be available from the second-year study. Findings of this study will be very useful for goat producers in Alabama and neighboring states for enhancing pastures and reducing production costs, which will eventually promote the sustainability of goat farming.

References
Littell, R.C., G.A. Milliken, W.W. Stroup, R.D. Wolfinger, and O. Schabenberger. 2006. SAS® for mixed models. 2nd ed. SAS Institute Inc., Cary, NC, USA. 814 p.

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