Saturday, 14 October 2017

HSNO Regulation Economics

Rod Oram has highlighted two facts about New Zealand's EPA
  1. It is using a new method called "net benefit" to evaluating hazardous substances and new organisms; and
  2. There is no written description of the new method.
Gleaned from an interview with EPA Chief Scientist Jacqueline Rowarth, Oram tells us that the net benefit method entails...
weighing up the financial, health and environmental costs of a substance against its economic benefits. For example, Rowarth says, Roundup, and other forms are glyphosate, are highly beneficial to farmers because they reduce weeds and significantly increase crop yields.“It’s a very difficult calculation,” she says. However much economics goes into the analysis, “ultimately there is a final point that becomes subjective” about wider societal values.
Exactly how does that work? I asked her. “We’re trying to formalise that because more people are challenging decisions. 
Does the EPA have a guide to this methodology? “I’ve been exploring this in press articles…and a document is being prepared internally on this.”
So basically they're making it up as they go along. Instead of sticking with the precautionary principle, the EPA seems to weighing up things without measuring them first.

Worse, there appears to be no international guidance on how to do this. On the contrary, according to Rowarth...
The EPA is a world leader for its work on “net benefit” analysis.... “Our scientists are being invited abroad” to give presentations on the methodology,
To me, this sounds like another round of the "light-handed regulation" New Zealand used for privatised monopolies in the 1990s. Pushed by extremist economists, this ill-fated idea was also hailed as world leading. Not one country followed though, so we weren't so much leading the world as heading off down a blind alley. Eventually, New Zealand endured a very painful re-calibration of regulatory expectations, though not before the privateers locked-in $2-3bn of un-earned capital gains in the electricity distribution sector alone.

As part of the re-calibration, the Commerce Commission as regulator was instructed by Parliament to develop "input methodologies" setting out in detail how regulation was going to be applied, to consult on these methods and for its decisions to be subject to a specially-enabled High Court review. All of this effort was designed to avoid regulating "on the fly" as the EPA now apparently does.

So the omens are not good. But what are the economic arguments against the EPA's novel method? There are two: it is conceptually wrong; and it is fraught with severe practical challenges.

The Concept
Back in the late 90s I visited a colleague who was an economics professor at Stanford and learned that a common description of a hopeless student there was "not clear on the concept".  In this EPA matter, the concept is the precautionary principle which goes like this:
if an action or policy has a suspected risk of causing severe harm to the public domain (affecting general health or the environment globally), the action should not be taken in the absence of scientific near-certainty about its safety
Notice that the level of risk is not specified and could have a low, even a very low probability. What matters is that "severe harm" might ensue. Examples of potential severe harm in the HSNO context include widespread disruption of human endocrine systems, depression and other forms of mental illness, and unintended consequences from the outdoor release of GMOs. These all count as "severe harm". Under the precautionary principle the onus would be on those seeking approval to prove "scientific near certainty".

One economic rationale for this approach is that disasters are best avoided if possible. Disaster insurance might possibly help, but ask the good people of Christchurch if they feel properly compensated. Or try to buy insurance against the expected mega-quake from the Hikurangi Subduction Zone

In the HSNO context though, the potential disasters are not natural in the sense of being beyond human influence. Far from it, any disasters will be the result of decisions made by humans at the EPA to approve the release of hazardous substances and/or new organisms. We can't insure against these disasters, so the EPA should not expose us to them.

The effect of the precautionary approach is to place an onus of proof on those wanting approval for a HSNO and to set a high bar (near certainty) for that proof. This is fully consistent with the real options literature, which requires that the timing of irreversible decisions made under uncertain conditions be delayed until the upside benefits are well in excess of the potential costs.

By contrast, the net benefit approach is based on expected values. If the EPA's probability-weighted assessment is that benefits exceed costs, then it will release the HSNO.

Here's a way to think of the difference between these approaches. Imagine you were in charge of Christchurch back in the day, and you had to decide whether to allow houses to be built on liquifaction-prone land. The precautionary principle would direct you to avoid exposing people to disaster, so you'd decline the request, markets would adjust and houses would be built somewhere else.

The property developers who bought swampy land cheap and now want to build houses will be advocating the net benefit approach. They'll have plausible-sounding economists and power-points for Africa, and they'll be regaling you with all the massive benefits of seeing things their way. If you ask about the risk of disaster, they'll assign it a tiny probability so that an expected (probability-weighted) value analysis aligns with their request, while gently suggesting that perhaps you shouldn't be such an old worry wart. 

So, yes, there is a huge difference and no, the net benefit approach does not properly accommodate disaster risk. That's why we use the precautionary approach.

Incidentally, the precautionary principle is baked into the HSNO Act. The purpose of the Act (s4) is to
protect the environment, and the health and safety of people and communities, by preventing or managing the adverse effects of hazardous substances and new organisms
To me, if you 'protect' a thing or person you would ensure they were not exposed to even a small risk of disaster. Parents of young children are usually clear on this concept. 

Section 7 of the HSNO Act is titled "precautionary approach" and requires that
All persons exercising functions, powers, and duties under this Act ... shall take into account the need for caution in managing adverse effects where there is scientific and technical uncertainty about those effects.
Finally, Schedule 1AA of the Act is the Stockholm Convention on Persistent Organic Pollutants which is explicitly based on the precautionary principle.

Practicalities of Net Benefit Approach
You'll have gleaned by now that I think the EPA is barking up a blind alley, probably the one where Jacqueline Rowarth buries all the strawmen she keeps murdering in the popular press. For the record though, I should just finish with a few questions for the EPA in the event that it proceeds down this track. I'll focus on glyphosate for now....

1. How do you measure annual and cumulative exposure to glyphosate for New Zealanders?
2. What probability do you assign to a New Zealander contracting cancer from exposure to glyphosate?
3. How did you estimate that probability?
4. In your model, what is the cost of a New Zealander contracting cancer?

Saturday, 7 October 2017

Strike Three: Rowarth has to walk

We all make mistakes and some people are psychologically incapable of admitting or apologising for them. This personality trait is probably detrimental to a scientist's career, but need not be fatal if the mistakes are few, minor and uncorrelated.

None of these defenses is available to Jacqueline Rowarth, who is still the Chief Scientist at NZ's Environmental Protection Agency despite committing three significant and correlated errors in less than a year, in the opinion of other scientists.

Strike One
Rowarth's appointment was reported on 10 August 2016 and she took up her role at the end of October 2016. Even before getting her feet under the desk, on 3 October 2016, she claimed that the Waikato River was one of the five cleanest rivers in the world. The Freshwater Scientists' Society schooled her publicly, noting her reliance on poor quality data that was also out-of-date. The Society's president Marc Schallenberg also commented on a later statement from Rowarth:
Ms Rowarth's later comments in an letter to NZ Farmer that E Coli in the river would pass the European Union's swimability test were also wrong, he said. He said she used median values and not maximum values to assess the data.
To my knowledge, these embarrassing errors have never been acknowledged or corrected by Rowarth. For it's part, the EPA chose to focus on timing details, saying:
"it would be comment on statements she made while employed in a previous role".
Strike Two
On 20 April 2017, Rowarth and Doug Edmeades participated in a radio discussion about whether freshwater scientist Mike Joy is an extremist. Edmeades had previously supported Rowarth's false statements about the quality of the Waikato River. This discussion prompted the NZ Association of Scientists to write to its members with a "reminder of the rules" concerning public debates between scientists. Association President Craig Stevens was quoted as follows:
"In this particular area we're talking about freshwater and land use. "It's an issue that's incredibly important for New Zealand from a number of perspectives. "We were concerned that some of this was proceeding in the media in a way that was not helpful for getting the facts across."
Again, Rowarth declined to comment.

Strike Three
One of the roles of the EPA is to regulate pesticides. It is well known that the International Agency for Research on Cancer (IARC) has decided that glyphosate is probably carcinogenic. Note that this is raw glyphosate, not the stronger formulations sold to farmers in New Zealand.

The EPA recognises IARC as “one of the two respected sources for information on carcinogenicity” but decided to not to accept its determination on glyphosate, commissioning an alternative review of the same evidence from a single NZ scientist, Wayne Temple, who as luck would have it came to the opposite view, that "glyphosate is unlikely to be genotoxic or carcinogenic to humans".

Rowarth has been working hard to support the EPA's position but running into serious scientific criticism including this strong piece from sciblogs, which itself leans on background work by former Green MP Steffan Browning and independent researcher Jodie Bruning. Now the issue has finally hit the mainstream media with this Rod Oram report, noting among other howlers that the Ministry for the Environment is reviewing the whole EPA, quoting Sir Peter Gluckman as saying "We don’t fully understand what they [the EPA] do" , and that Rowarth is not aware her employing agency is under review.*

I will have more to say soon about the EPA's "net benefit" approach to pesticide regulation, on which Rowarth is relying in the glyphosate matter.

Meantime, these three episodes make it painfully clear that Rowath is a national embarrassment to a country that markets itself as 100% Pure, where most citizens genuinely care about our environment and many are actively striving to live up to the slogan. She has to go.

*Update 8/10/17: It seems that Peter Gluckman's comments about a review were mis-interpreted: MfE is constantly responsible for monitoring the EPA but no special review is underway.

Thursday, 5 October 2017

DairyNZ Director Elections

DairyNZ is a statutory monopoly, empowered by Parliament to levy all dairy farmers and spend the cash on "industry good" work, including research. The directors of DairyNZ are responsible to levy-payers. We trust them to direct the management of DairyNZ in spending the funds we provide. So the election of new directors, closing at noon on 24 October 2017, really matters if you care about the scientific direction of this industry.

In 2015, DairyNZ offered an online Q&A facility where we could post questions for director candidates to answer, out in the open where everyone could see. For frankly flaky reasons, that facility is no longer enabled, though it still sits there behind the DairyNZ website.

I used the online facility in 2015 to ask candidates about their views on funding research into biological farming, written up here. Responses ranged from supportive (2 candidates) through demanding proof the research would have a positive outcome (3) and buck-passing to other agencies (4), all the way to the bottom where 1 guy flatly denied there is anything new to learn.

That last guy, the denialist, was not just elected but made chairman of the board of DairyNZ. Michael Spaans was also a Fonterra director, but in January 2017 he "stepped down from the boards of Fonterra and DairyNZ, citing ill-health". He seems to have got better though, enough to be back in the driving seat at DairyNZ anyway.

Against that background I emailed the six director candidates for this election, pointing them to this post about some very cool nitrogen-fixing bacteria and posing the same questions used in 2015:
Despite the critical role of soil in pasture-based dairying, DairyNZ has no research efforts looking at how to harness/farm the biological life in soils. If elected, would you advocate for such research? Why or why not?
Four of the six candidates responded, the omissions were Cole Groves and Jim van der Poel.

Ian Brown went for the "prove it" camp, saying that he would
need to see a case put forward to understand the benefits that may accrue to dairy farmers and the industry as a whole
What Ian is really saying here is "bring me a company that expects to make cash out of this idea". As if that's the only test of potentially valuable industry good research. It doesn't occur to Ian that there could be different ways of doing things that are (a) much better for farmers but (b) won't increase profits for any existing suppliers to dairy farmers.

Colin Glass didn't address the questions but he did send me a long email that sounded like his stump speech.

Grant Coombes did much better. He'd read the background material, endorsed a couple of the key points and committed to advocating for "a larger % spend on all R&D including soil science". That's not what I was hoping for as an outcome to be honest. I have no opinion on whether budgets should be shifted from outreach etc to R&D: what I'm asking for some investment into the biological aspects of soil science.

The stand-out winner was Mark Slee, who I later discovered already has a record of achievement in sustainable dairying. Despite this background Mark said "Biological farming is not an area I have explored but I’m keeping an open [mind] on all possibilities moving forward". Nor was this just lip service: Mark also said he is attending the field day at Brian Clearwater's farm near Peel Forest on 12th October to get "better informed about biological farming practices". Then he did some more digging and emailed the next day with some slide packs about the Backtrack farm where there is a matched trial underway, supported by DairyNZ, that apparently has a biological focus.

Mark gets my vote and I hope he'll get one of yours too. He's not an advocate for biological farming, far from it. But he's open-minded enough to seriously consider it, which is all you can ask for in a research director.

I'll admit that as a practitioner I'm nervous about how Mark will react to the field day at Brian's place. A lot of what we do is a direct challenge to standard agronomy, which is why the vast bulk of scientific agronomy doesn't even consider these methods. That makes them under-investigated, not inferior or fatally flawed, as you might gather from reading certain pundits in the rural press. 

Science works on falsification. Unless and until DairyNZ can prove there is no value in trying to foster soil biological life, it should be actively investigating the potential benefits.

Wednesday, 27 September 2017

On the selling of markets

Markets in everything is a recurring theme on the popular economics blog Marginal Revolution (sample). The underlying idea is that markets arise naturally to co-ordinate voluntary exchange and it's often best for governments to just keep out of the way so this can happen.

Sometimes government is already "in the way" though, and markets won't arise without help. The NZ wholesale electricity market is a good example. With government assistance, this market opened in 1996. It was entirely unregulated until 2003 when a regulator was installed after persistent failure by the industry to agree on its own self-governing rules.

The more interesting cases are where governments want to coerce private agents for broader economic reasons. Greenhouse gas emissions are a good example. New Zealand has made commitments internationally and the government is on the hook financially for those commitments. There is a strong economic case for obliging emitters within New Zealand to pay their own way, rather than have the taxpayer pick up the tab, which is effectively a subsidy. Pricing doesn't just force polluters to pay though, it also underpins the business case for investing in mitigation.

It's well known that there are two basic ways of pricing emissions: a tax, which regulates the price; or a cap which regulates the quantity and promotes trading. Suzi Kerr has recently outlined the relative merits of these options, focusing (rightly in my view) on the promotion of certainty and concluding that "if you want more certainty, work for stronger political consensus and stable policy". Suzi notes that the price of carbon has been undermined by politicans in Australia and New Zealand, despite there being a tax in Australia and a trading scheme (ETS) in New Zealand. 

These are terrible outcomes for both countries because they strand mitigation investments and make future investors fear the same treatment. In what follows, I'm going to assume we've solved the political problem somehow, for example by using legislation that seeks to bind future governments such as Reserve Bank Act. Now, should we prefer a trading scheme or a tax? Well, if price certainty is what we're after the answer is clearly a tax.

That's the wrong answer though if you have an ideological aversion to taxes. This is why, when other forms of pollution become public issues, the NZ Initiative needs to push a different line. Thus, the water tax proposed by Labour is characterised as "guessing at prices" as a preface to discussing trading schemes. Eric Crampton recently outlined such a scheme...
Set a catchment-level cap on water extraction so that the aquifer is sustainable, set a minimum river flow so that the river is a river, then run the kind of trading regime that Raffensperger and Milke designed.
This is not an alternative to anything relevant, including the status quo. As I outlined previously, we already have catchment level caps in place along with an obligation on the relevant councils to eliminate over-allocations. Moreover, there is already a secondary market for irrigation water in Canterbury (the current price is around 80c/cubic metre) and the next round of plans at other councils is already enabling such markets elsewhere. Feel free to deride the Canterbury market as lacking depth and liquidity though: these are definitely over-the-counter trades rather than the stuff of an economist's wet dream, but that's because of limited demand for trades. Until recently, exactly the same criticism would have applied to the wholesale market for natural gas in New Zealand, and it can still be levelled at wholesale hedge contract trading of electricity in New Zealand. Yes there can be markets in everything, but only if/when/where enough people want to trade.

Neither is Eric's plan an alternative to a water tax of the type promoted by Labour because it yields no revenue for cleaning up waterways. Which is probably the point. If your aim is less government, you'll instinctively resist things that would give them more money.

Now let's get below the proposed water tax to the underlying environmental quality issues. Take nitrate pollution as an example, though the concepts apply equally well to pesticides and other things that pollute the physical commons. We have two problems here: one is ongoing pollution and the other is cleaning up past pollution, lots of which is yet to become obvious.

The more market approach is to cap the quantity of something, thereby creating the scarcity needed for a market to function. Obvious problems include: whether to cap inputs (eg urea) or outputs (eg N leaching as estimated by the model urea sellers developed and own); how exactly to decide the number of free units to gift to existing farmers (a lobbyist's paradise, right there); and how to pay for the clean up. Eric will be along shortly to talk you through these details.

The tax approach is to estimate the environmental cost of nitrate pollution and set this as a tax. I'd favour taxing the input because it's less costly and because I don't trust the model used to predict leaching. The tax revenue can then be used for clean-up.

If you've been following along, you'll have noticed that trading schemes have one political advantage over taxes: you can pay off polluters with free credits. Not fully, because you do need some scarcity to force people into your market, but the squeaky wheels can be greased. Taxes will have a greater impact on behaviour and therefore meet stronger resistance. This is why it makes sense to use a glide-path with low initial rates increasing over time to allow people to adjust, much as suggested by Lance Wiggs.

Friday, 22 September 2017

Helping Plants Fix Nitrogen

There's an interesting story in the latest Modern Farmer about work by Bayer that seeks to persuade ordinary plants to fix nitrogen from the atmosphere, the same trick legumes do in a joint-venture with Rhizobia. It's well worth a read if you're into sustainable farming.

For me, this story underlines two sad facts. If you'll bear with me while I describe them, I'll reward you at the end with a positive suggestion.

The first sad fact is that agricultural science has been fully corrupted by private money. When DairyNZ spends our levy money on research it frequently partners with the private sector. This biases the research away from general purpose technologies in favour of things that can be more narrowly commercialised. For example, instead of seeking to understand below-ground farming by examining options for fostering various bacteria, fungi and protozoans, we get "precision agriculture" research aimed at getting the most value out of bagged urea. This is partly because the urea vendors want to paint themselves as good guys (while still selling lots of urea) and partly because other folks are keen on selling the sensors and other equipment you'll need for precision agriculture.

Mainly though, its because DairyNZ can't imagine that biological farming as practiced in New Zealand could be worth investigating. The notion that promoting symbiosis between plant roots and living organisms in the soil could reduce the need for bagged fertiliser seems offensive on some visceral level. Have a read of what happened when I asked DairyNZ folks about this a couple of years ago.

Second, and equally sad, we're going to have to either figure this out for ourselves or wait until our kind input suppliers have figured out how to turn a dollar out of it. We've known for some time that the big agchem companies are quietly working away on biological methods, knowing of course that today's input-intensive agriculture is looking less and less sustainable as time goes on. The Bayer project reported on by Modern Farmer is further evidence of this plan.

It's plausible to argue that it doesn't really matter too much if this new frontier of farming ends up being sold to us by Bayer and their mates. I'm less sanguine, partly because this approach will probably take much longer than a collective research effort aimed at creating a general purpose technology. The reason is that Bayer don't just need to make it work: they also need to make it work in a way that delivers revenue to Bayer. By contrast, if we were doing the actual public good research DairyNZ is supposed to be doing, the revenue consequences would be irrelevant. A larger set of methods would be available for consideration so it'd be easier & quicker to find one that worked.

OK. So much for the misery. Here's the bright spot: you can try exactly this same trick at home. Bayer understandably didn't disclose the bacteria it is working with, but there's a strong possibility it'll be Azotobacter chroococcum, first discovered in 1901. Read about this wonderful bacteria here. We've been buying it in bags, mixing it in with our foliar sprays, and using it to inoculate seeds before sowing. It seems intuitively plausible that sustainable populations of this bacteria could become established under suitable soil conditions, at which point there would be no need for further spreading.

Thursday, 21 September 2017

Bullshitters Paradise

It was always on the cards that deceit would play a big role in New Zealand's election, having been so successful in the 2016 Brexit referendum and US elections. Britain's experience showed us that egregious bullshit can be very effective, using this bus to pretend that the public health system would be massively better off under Brexit.

Around the same time, in the US, highly-targeted deceit services were being sold to the Russians by Facebook, and the establishment candidate was making a ridiculous claim that his administration would build a southern border wall paid for by Mexico.

Both of these claims blur the Frankfurt boundary between bullshit and lies. Even if they start out as bullshit, once the questions start being asked the lies emerge.

I once worked with an economist who built an expert witness business this way. He took it as a challenge to support outrageous ideas for well-heeled clients. These reports would usually feature a bold claim, backed by plausible rhetoric, lots of literature citations and plenty of tables and charts: weighty. Questioned, he'd first stick to his guns until things got too intense, at which point a different second order claim would be advanced as if it were support for the first. Nail him on that one and you'll get a third order claim, and so on. This strategy often works, so he got lots of work. Eventually he got caught out under a cross-examiner's blowtorch and called out in the judge's decision as an advocate rather than an independent expert: end of career.

Political process are much less intense. Bullshit can morph into lies without being exposed because there is no judge solely charged with determining the truth. The news media does its best, but is ill-equipped to cope with the flood of bullshit and indeed relies for its content on access to the bullshitters.

This is why we are still seeing big lies put about, long after they've been thoroughly debunked, such as:

  • Britain's 350m pounds/week for the NHS;
  • Trump's stupid border wall & its funding by Mexico; and closer to home
  • Steven Joyce's mythical $11.7bn.

Let's give the Minister of Finance the benefit of the doubt and assume that he made an honest mistake when claiming Labour had an $11.7bn hole in its fiscal plan. It was a bold claim and he got it wrong according to every independent economist willing to comment publicly. He got confused about what was in the different budget lines. Mistakes happen: we've all made them. No big deal.

Except if you're unwilling or unable to admit it, like the economist described above. Then you head off down the rabbit holes looking for salvation in second- and third- order arguments. Which is where we are now, on Mr Joyce's account.

Last night, the PM repeated the $11.7bn lie on national television and this morning, the blogging wing of the ruling party posted this report based on work by some un-named economist, who reckons there is still $10.7bn missing.

Having looked at the figures, I can see why this economist is so shy. They've somehow forgotten that the three big line items in government spending (welfare, health + education), which account for 60% of all government spending, are already inflation indexed in Labour's fiscal plan. The allowance required to cover "additional line item spending" is therefore $4.2bn, not $23.5bn. Instead of having a shortfall of 10.7bn, Labour has headroom of $8.6bn.

Are you mesmerised yet? Because that's the aim: you're supposed to get so sick + tired of all the detailed argument that you declare a pox on the whole issue while retaining a suspicion that maybe Labour can't actually do basic arithmetic.

Welcome to the bullshitters paradise.

Thursday, 7 September 2017

Meet our cows

Due to the popular request of one dude on Twitter, this post is about our cows.

We inherited a mixed herd when we bought this place: quite a few Jerseys (the brown ones), a smaller number of black & white Friesan, with the bulk of the herd being cross-bred. We're not too keen on the Fresians because our farm is 25% hills and we milk once-a-day. Fresians are generally larger, less agile on hills and while they produce more milk it contains a smaller percentage of milk solids, which is what we get paid for. Strong udders are essential for once-a-day and our thinking is that it's better if cows are carrying around milk with a higher solids percentage.

The life cycle of a dairy cow begins in the springer paddock, which is where all of the soon-to-calve cows live. Here's a newborn calf taking its first drink from its mother.

They are alone because all the other cows are eating the fresh grass behind the camera that I'd just opened up. Mum was more concerned to complete the birthing process than get a feed of the new grass, so she stayed there for a while, eating the afterbirth and licking her calf clean.

Sometimes it's difficult to match up calves with their mothers. A version of the aunty problem is shown below: they're all interested in the calf but only one is the mother.

Once we've decided on the mother calf pairings, we give the calf a numbered necklace and record the cow & calf numbers together.

Then we leave them alone for at least 24hrs and often 2 or 3 days, contrary to the advice of DairyNZ who say calves should be collected twice a day and fed colostrum to ensure they get those vital mother-child antibodies. We prefer to trust nature. We do monitor things and ointervene if we see this is not happening. Some cows are shocking mothers, and some calves go wandering.

There is no good time to separate a calf from its mother. Beef farmers leave the calves on for several months, and both animals suffer when the resulting strong bond is broken. A couple of seasons ago we left all the calves on their mothers for a month or more and the pain of separation after that was just awful to behold. Now we take the calf when it is 1-3 days old. The high-bred girls stay with us here, and everything else either goes to slaughter or to other people who grow them on for later slaughter.

Either way, all calves come into the shed where we give them dry bedding and milk twice a day. They generally take to the milk feeder pretty well, like these little ones...

Roll forward one year, and those little tykes will look like this.

These are some of our replacement heifers, born last spring and rapidly turning into full sized cows. We'll put some young bulls in with them in mid-October. All going well, by this time next year they'll have calved and be supplying milk. For now though, we're trying to keep these girls growing strongly despite the inevitable feed pinch in late winter / early spring. We make a lot of good hay in the summer and are feeding it to these girls right now: that steel contraption in the foreground is a bale feeder attached to the back of a tractor.

After cows have calved they go into the colostrum mob. Their milk can't be put into the vat for collection/sale so we use it to feed calves. These colostrum mob cows have eaten all their grass for the day and are now scoffing grass silage.

We keep a close eye on the colostrum mob. Eight days after they've calved we start testing their milk for any evidence of mastitis. As soon as a cow's milk is clear, she gets drafted out and put in with the main milking mob. This mob (below) gets the best of everything: plenty of grass, silage top-ups as required, mineral licks, ad-lib salt.

I was hoping to post some pics of my favourites, but that'll have to wait for another day.