A Watussi steer with perfectly aurochs-like horns

Recently I found a video of a Watussi individual with very aurochs-like horns. Normally, Watussi bulls' horns look more like that. This individual however has horns that have a perfectly aurochs-like curvature (yes the horns are very large, though there were Pleistocene aurochs bulls with horns only a little smaller). I was not surprised that this individual is obviously a steer. Steers often tend to have more aurochs-like horns. Why is that? I explain this in this post. Horn length and consequently shape is determined by developmental factors. Development is deeply changed in domestic animals, usually there is a premature stop in development, causing the animals to display paedomorphic features. Thus it is not far-fetched to assume that horns tend to stop growing earlier in domestic animals, producing the horn shapes they have (usually less curved than in the aurochs). Steers, however, have an atypical development as their gonads are removed. The body does not know when to stop development and thus they grow larger, taller and also the horns grow longer (for another example, go here). Coincidentally, this developmental elongation compensates the developmental delay that results from domestication, resulting in a wildtype-like outcome. This is what we see in the Watussi steer. 

This has two implications for "breeding-back". For once, it means that bulls with banana-shaped forwards-facing horns (as we see it in many primitive breeds and "breeding-back" cattle) actually have the right genes for an aurochs-like horn curvature (the horns would also end up longer). It are developmental factors that result in the domestic condition. Furthermore, the big question is then: can "breeding-back", with the cattle that we have, produce perfectly aurochs-like horns at all? Selecting just on the phenotype that we want would not reverse the developmental changes from wildtype to domestic that we have in cattle. However, there are occasionally bulls with horns very close to the original aurochs horn shape, such as some Maronesa bulls (and also cows). And maybe it is not a coincidence that this breed has also retained a substantial degree of colour dimorphism. 

Two Tauros bulls with good horns

Most examples of Tauros cattle from the Tauros Programme don't have that good horns. Mostly they face outwards too much and lack the inwards curve. This goes for cows as much as for bulls. However, today I was addressed to two photos of two Tauros bulls with comparably good horns from the Loozerheide, Netherlands. 

Go here and here. The head of the first bull resembles some Taurus bulls quite closely. The second bull might have Maronesa ancestry but I could be wrong on that. 

It's really good to see Tauros bulls with such nice horns, it makes me hope that future Tauros cattle will develop better horns than the current majority. However, I think the project still needs a breed that reliably and truly adds slenderness, long legs and large size. Maremmana alone probably will not do it.