Secondary Effects of Behavior-based Pasture Management

Secondary Effects of Behavior-based Pasture Management

Summary

During this reporting period, we conducted the goat feeding trial at the University of Hawaii research station to evaluate any effects of Christmasberry (Schinus terebinthifolius) and indigo (Indigofera suffruticosa) on internal parasite loads as indicated by fecal egg counts.  While goats used in the experiment had access to both Christmasberry and indigo at their home ranch, for reasons undetermined, only a few goats ate any significant amount, offered making data difficult to interpret. This experiment will be repeated this year to attempt to get a better intake and measure any response.

Ordering and acquiring GPS collars proved unexpectedly difficult and lengthy. The PI contacted four vendors and eventually found one (Lotek Wireless) that met project needs slightly in excess of budgeted expenses. The collars apparently had to be manufactured upon purchase, a process that took several weeks. Thus deployment of GPS collars was delayed until December 2013. It is anticipated that a no cost extension will be requested as to make up for delays to capture both wet and dry season data, which has more significance to producers than data from one season alone.

We produced a brief video on livestock bonding for display at the Hawaii Cattlemen’s Council convention held November 15 – 16, 2013. Approximately 200 people attended the event and several visited the booth with the looped video. The PI received many positive comments and interest in the project based on the video.

Objectives/Performance Targets

Objective 1: Quantify effects of certain pasture plants during wet and dry season on internal parasite loads of livestock. Performance Target: Aim to have trials completed by month 12 (July 2013) following project start conducted at the UH College of Tropical Agriculture and Human Resources (CTAHR) Kauai Agricultural Research Center (KARC). 

From July to August 2013, 32 goats weighing on average 18kg were borrowed from Tony’s Goats (Kapaa, Kauai) for this trial and located on a two-acre napier grass (Pennisetum purpureum) dominated pasture at KARC. The goats were acclimatized for two weeks and rotated every five to seven days through four paddocks. During this period nine goats were pulled from the project owing to health reasons, such as heavy parasite load or foot problems. We thus eliminated the Christmasberry + Indigo treatment group for his round leaving Control (seven goats), Christmasberry (eight goats) and Indigo Supplement (eight goats) treatment groups. For supplementation, indigo was collected from Haupu Ranch near Nawiliwili Harbor, and Christmasberry was collected from the roadside near Puhi. The control supplement was at first a commercial feed of similar quality to the other treatment groups, but this was changed to napier grass on day five of the trial, owing to the fact that the other groups were not eating much of their supplements. These supplements were promptly refrigerated and fresh samples were collected every other day. Eggs per gram of strongyloid type eggs was determined for each goat by a Modified McMaster method before first supplementation to establish a baseline infection rate. Goats were also weighed before and after the two week feeding period. Initially, goats were penned overnight and offered the supplements for two hours before removing and weighing refusals and releasing goats to pasture. Fecal egg counts were again determined after seven days. As very little of the supplements were being eaten in the two hour period, supplements were left out in feed bins until evening for the final week. This increased intake, but overall intake remained low. Results and further discussion are presented in the Accomplishments/Milestones section.

Objective 2: Quantify in situ pasture use relative to parasite loads and weed forage quality in animals trained to eat weeds and in untrained animals using GPS collars. Performance Target: Complete at least two observation periods per ranch by end of month 12 following project start (July 2013).

Purchasing and acquiring GPS collars turned out to be an unexpectedly lengthy process. One vendor was identified out of four to meet our project needs and could meet terms close to but slightly over our budget. The collars are apparently made to order; a process which took several weeks. We received them finally in the middle of the above feeding trial, which took priority at the time. In coordinating with ranches, we decided to deploy the collars first with Haleakala Ranch in meeting Objective 3 in December 2013. Furthermore, one project collaborator, Tom’s Goats, sold his business, making those trained animals unavailable. New groups will have to be trained to eat weeds on Kauai or fed weeds to make this Objective make sense.

Objective 3: Quantify any differences in pasture use by bonded animals compared to non-bonded animals. Performance Target: Complete at least two observation periods at Haleakala Ranch by end of month 12 (July 2013).

We deployed GPS collars on two goats, two sheep and two cattle that were part of a bonded group in December 2013. We collected location and head position data for two weeks on a five-minute cycle. We will deploy collars again in the next month on non-bonded animals to compare pasture use, namely in proximity to other species.

Objective 4:  Generate management recommendations based on findings. Performance Target: Publish results and recommendations by month 18 (December 2013).

Obviously, delays in acquiring equipment and poor performance of the feeding trial necessitating another run has delayed this timeline somewhat. We are working on collecting data to give meaning to any recommendations that can be made.

Accomplishments/Milestones

Objective 1

The penned goats ate very little of the supplements offered, from 2.2 – 4.4% of their estimated daily dry matter intake across treatment groups (Table 1). Intake increased after leaving supplements available for the entire 12 – 14 hour grazing period. 

Figure 1 shows a nominal decline in mean eggs per gram (EPG) determined by treatment group. Given the small amount of supplements eaten, any causal relationships drawn would be spurious. Furthermore, all groups maintained levels higher than 1,000 EPG, which is often considered a point when to treat with dewormer.

Objective 3

We deployed GPS collars at Haleakala Ranch in December 2013 to track how bonded livestock use a pasture (Figure 2).  The data are currently being analyzed.

• Table 1. Average dry matter intake per head per day by treatment group; Range of total grams eaten per head per day; and average percent total daily dry matter intake by group.
• Figure 2. Two heifers, two goats, and two sheep bonded together were collared to study pasture use for a period of 2 weeks in December to January 2013 – 2014.
• Figure 1. Eggs per gram (EPG) as determined by fecal egg count averaged by treatment group. The orange line indicates a level above which requires deworming treatment.

Impacts and Contributions/Outcomes

We created a brief video introducing the concept behind multi-species livestock bonding for presentation at a booth at the Hawaii Cattlemen’s Convention in November 2013. Approximately 200 people attended the convention, representing the bulk of the state’s cattle producers. Several in attendance also raise goats or sheep in addition to cattle. The video was well-received based on feedback given in-person at the convention and follow-up inquiries made to the PI. A copy of the video can be sent upon request owing to technical problems converting the video to a format accepted by the SARE database.

Collaborators: