Heartwater, the Kidding Season and Handling Goats as Goats

#The thermometer said no, and twenty-two goats died anyway

Twenty-two Boer goats died in a week in the Cathcart region of the Eastern Cape, with thirty to forty more on neighbouring Gwatyu. On clinical evaluation the animals had normal temperatures. At Onderstepoort a Saanen doe went down with hypersensitivity, flicking eyes and paddling legs at an ordinary 39 °C; she was worked up as a pituitary abscess and confirmed as heartwater only on a brain smear at post-mortem (Leask, Pettey & Bath, JSAVA 84(1), 2013).

Rule heartwater out on the thermometer and you will miss it. That is the shape of everything here: the thermometer, the FAMACHA card and the sheep race are all tools calibrated on another animal.

#The tick that decides where you can keep goats

In the Mnisi communal area of Mpumalanga, Amblyomma hebraeum — the bont tick — made up 66.2% of adult ticks collected off goats. Ehrlichia ruminantium, the heartwater organism, was in 17.4% of adult ticks and 28.4% of pooled nymphs. The tick was there all year, with adults peaking in November and nymphs in July. The authors call it "a major obstacle preventing the upgrade of local goat breeds" (Mnisi survey).

The authoritative statement on susceptibility is qualitative: imported breeds of sheep and goats, "especially Angoras", are highly susceptible, while indigenous populations of endemic areas may be resistant, and stock under nine days old carry a natural resistance unrelated to the dam's immunity (Yunker, 1996). Mortality percentages for naive goats circulate widely, are not in that review, and should not be repeated.

The afebrile picture is documented in Boer goats and in a Saanen. The authors record that it has not been diagnosed in any indigenous breed other than Boer goats. Upgrading an indigenous herd with a commercial ram buys growth rate and buyer familiarity — and this risk with it.

Mnisi also changes where you look. A. hebraeum adults and nymphs preferentially attach in the interdigital space between the claws, causing secondary infection and lameness — seen in 89% of households. Check ears and never lift a foot and you are inspecting the wrong end of the goat.

Your risk assessment has three local parts. Is the vector here? This course's research could not establish whether Amblyomma hebraeum occurs at Meyerton or in Sedibeng — the biggest open question behind the Delta Farms health plan. Ask the state vet; do not assume either way. What have your animals been exposed to? The goats that die are the over-protected ones and the ones trucked in clean; the handbook's advice is to hold immunity "by letting a small number of ticks stay on the animals" (Handbook). What season is it? Your own tick counts across a year beat any published curve.

#FAMACHA in a goat: use it, and know what it misses

FAMACHA is a South African invention: score lower-eyelid colour on a laminated card, drench only the anaemic animals. It came out of a resistance crisis. Resistance in Haemonchus was found on all 52 farms surveyed in Mpumalanga and KwaZulu-Natal, 8% of strains were under 40% susceptible to all four anthelmintic groups, and the authors called SA's resistance level "possibly the highest that has so far been recorded in the world" (Van Wyk et al., 1999).

Three limits, and a goat farmer needs all three.

It detects anaemia, so it covers the blood-suckers — principally wireworm. Tapeworm, conical fluke and the scour species are invisible to it; the field handbook prints this in capitals. A pot-bellied, poorly grown kid with good pink eyelids still has a worm problem. It runs the other way too: a pale animal in mid-winter may be anaemic from something other than worms.

It is less well validated in goats than in sheep, and its own authors say so: "The FAMACHA system may not be as applicable to goats as to sheep, but further work is necessary" (Van Wyk & Bath, 2002). Its supporting trial data came from sheep, including a Merino stud.

The resistance surveys were on sheep too. Goats clear many anthelmintics faster, so the position is probably worse rather than better — but that is inference, not SA data.

There is SA goat evidence for targeted treatment. In a Bergville, KwaZulu-Natal trial with 172 indigenous goats across 15 communal herds, a single mid-summer tactical treatment with copper oxide wire particles cut faecal egg counts by 89.0% against untreated controls — 2 347 to 264 eggs per gram, while controls drifted from 2 652 to 2 709 (Spickett, de Villiers et al.). Read the attribution: 89.0% is the tactical treatment's own effect, with FAMACHA-triggered symptomatic treatment running across both groups, and the authors conclude the two work together. Copper is a toxicity risk in small ruminants — a veterinary decision, and no product or amount appears in this course.

#Choosing the kidding season

There is no universally right kidding date in South Africa. There are three defensible ones, and the field handbook gives all three with their costs.

The handbook's own summary is that "the optimal kidding time is from April to September when the weather is drier and the parasite burden lower", with the recommended pattern mate November/December, kid April/May. The market lesson already gave you one reason to hold a six-week breeding season; here is the husbandry reason. Six weeks gives one uniform group of kids to manage, and it makes the barren does visible instead of letting them hide in a herd that kids all year.

Work it for a real farm. Sixty does on the Highveld, where wireworm runs November to April with the killing months late January to April, and cold snaps still kill kids in September.

• Spring kidding puts newborns into the September cold and their first three months inside the worm peak — both documented kid killers, on the same animal, in the same quarter.
• November kidding solves the cold and keeps the worms, and asks you to mate in June–July, when Highveld standing hay has already collapsed in protein.
• Autumn kidding drops kids as the worm season closes, weans onto crop residues, and — as the earlier lesson on the live-goat market showed — leaves well-conditioned animals running into the December and Easter peaks.

Here, autumn wins; on a sweetveld farm with a different calendar it may not. The rule is not the date. It is that you choose against your own parasite and cold calendar, then hold it.

#Handling goats as goats

A goat is not a small sheep in the race either. They move in family groups — work with the group rather than splitting it. They jump and they look for the gap: the practical SA answers are shadecloth hung over poles above the kraal walls, permanent fencing with proper gates, and interlocking slatted panels (about 3 m × 1.5 m) from a local engineering works — transportable, quick to erect, a high initial outlay with an almost indefinite life.

Stand behind the shoulder to push an animal forward; move briskly down the outside of the race in the same direction to move the group up it. Catch above the hock, never lower, or you damage the leg. Hold horns at the base, never the tips. Keep the goat upright when trimming hooves — and while it is up, look between the claws for the ticks from the first half of this lesson.

Least intuitive: habituation is a physiological necessity, not a nicety. The Angora lesson showed what acute stress does to a goat's blood glucose. A handled animal can be scored, weighed and loaded without spending reserves it may need.

Before the next breeding season, get your state vet to settle in writing whether Amblyomma hebraeum occurs on your farm, then pick up ten goats' feet and count what is between the claws. Those answers and your own cold calendar set your kidding date — and the kidding date sets most of the rest.