Nuer’s oxytocin

As I mentioned earlier in this blog, the Nuer people are strongly linked to cattle in complex ways that are not always understandable to us. What I will describe here is part of this people-cattle interaction that ensures the survival of both in rather harsh conditions.

As with most cattle belonging to African pastoralists, they are of a placid nature and used to constant handling from an early age and milk is probably the most important commodity they produce although sales of oxen are also practiced by the Nuer.

As it is common practice the world over, Nuer cattle are milked after the milk let-down have been stimulated by allowing the calf to suckle briefly and then withdrawn. This action stimulates nerve receptors in the cow teats which induce oxytocin release within a few minutes. This compound, a, hormone causes the cells around the milk-producing alveoli to contract and squeeze out the milk, pushing it down the ducts towards the teat as well as dilating the milk ducts making it easier for the milk to flow down them.

On a visit to a Nuer cattle kraal we came across a very unusual sight, even for a veterinarian that had worked with cattle most of the time. A Nuer woman was blowing strongly, rhythmically and repeatedly into the vagina of a cow for about five minutes, taking rests in between as the effort needed was evidently great.

After the operation, she proceeded to milk the animal, obtaining about one litre of milk. After a while, the process was repeated an more milk obtained.

Enquiries about the practice revealed that the cow had aborted recently but that it was also performed on those cows which have lost their calves or are giving poor milk yields. I took pictures to document the practice and these are presented in a slideshow at the bottom as they are strong pictures that show the operation in great detail.

Later, at the laboratory I checked the literature for this phenomenon and did not find any records of it among the books I had at my disposal. However, I learnt that stretching of the cervix induces oxytocin secretion, increasing uterine motility and probably it also induces milk let-down, probably explaining how the curious practice works.

Years later, in 2010, checking through old papers and pictures I found the notes and prints of the oxytocin observation in Gambela and looked for it on the internet. I found several interesting references to the practice, including one by Wilfred Thesiger during his travels through Sudan [1] and several references to the practice of “cow blowing” in Wikipedia [2] where I learnt that it was quite an ancient and widespread practice throughout the world and that Gandhi stopped drinking cow milk after he came to know about the process known as “phooka” or “doom dev” in India that he considered cruel.

It was the comprehensive work of LeQuellec [3] on the evidence of the practice in ancient cultures that called my attention and prompted me to get in touch with him to discuss my observation. He was interested and encouraged me to publish the observations and so I did [4].

Although the physiological aspects of the practice can be explained, it still leaves unclear in my mind how early “milkers” linked the insufflations with milk let down and started to use it to their advantage. Is it that they have seen milk dripping at calving time? Or is it that they believed the udder to be the end of a continuous system which starts in the vagina and blowing through it will expel the milk? I still do not know.

[1] Thesiger, W. (1983). Arabian Sands. Collins. p.48.

[2] See:

[3] Le Quellec, Jean-Loic (2011). Provoking lactation by the insufflation technique as documented by the rock images of the Sahara. Anthropozoologica 46, 65-125. See:

[4] de Castro, J. J. (2011). Nuer’s oxytocin. Cahiers de l’AARS — N° 15, 27-28.

Gambela fireworks

Another time in Gambela for work, after a successful day working successfully on our tick-infested cattle without getting stuck in the mud! When returning to the hotel after the work, we passed in front of the compound where the personnel from the Soviet Union [1] were housed. The place looked like a fortress and its gates were usually closed. That afternoon, however, the gates were open and we had a chance to see that there was, for a change, some movement but we did not stop to ask!

After my usual afternoon walk among the Nuer kraals nearby (a hung-up from my time with the Maasai), I went back to the hotel for a well deserved shower. As usual, tired, we decided to have an early dinner as we were departing early the following morning.

One of my walks among the Nuer cattle in the neighbourhood of our hotel. note that each animal is tied to its peg, ready to spend the night.

Regarding our muddy showers, we soon learnt how to handle them. The trick was to have plastic water bottles with holes punched at the bottom that we would hang from the shower head and, in this way, rinse ourselves from any remaining mud (sometimes we needed two though!). Apart from that, the rooms were comfortable and well-kept and the food adequate, all considering the circumstances.

Gambela hotel.

That evening as usual there were four or five dining customers and there was the habitual choice of either a piece of chicken or a beef cutlet, both with chips. We felt that our teeth were up to the challenge that particular night and asked for the latter that, as expected it took a while coming. That night, the importance of this issue was soon forgotten.

Suddenly we heard a few loud explosions nearby that shook the windows of the dining room to a point that I was convinced that they would shatter. “We are under attack!” I immediately told Mabel and we moved under the table, in case we were hit! Of course, we were not the only ones that did this and soon, all dinners were looking at each other in wonder through a forest of table and chair legs!

Although the heavy explosions did not happen again, there was intense shooting noises from what seemed to be heavy guns as well as the pop-pop-pop of the ubiquitous AK47s. In the middle of the confusion, we saw a pair of fast-moving legs going through the entrance door and that, after a few minutes, came back to announce something in Amharic that made people return to their food!

We imitated them while trying to find out what was happening. A waiter came and kindly explained to us that we were not under attack (relief!) but rather we were hearing a celebration by South Sudanese people stationed nearby. When asked about the reason, he replied that the Sudanese People’s Liberation Army (SPLA) had captured an important city (Kurmuk?) and the news had just arrived. Now we understood the movement we had seen earlier at the Soviet compound!

Knowing that we were not the target of the shooting we hurriedly finished our, by now cold food, and withdrew to the safety our room! While walking in the open we could see the green lines that the tracing bullets were drawing in the dark sky. As they seemed that they were being shot from places nearby, I decided to get my torch and go for a walk to investigate from a safe distance.

Perhaps one hundred metres from the hotel I found the first group of excited revellers (some probably drunk already). Lots of dancing was going on around a battery shooting in the air. Not being a weapons expert, I recall the battery I saw being a twin-barrelled gun that a recent search indicated that it could have been a ZU23 anti-aircraft gun. Satisfied my curiosity and after confirming that the atmosphere was one of celebration, I returned to the hotel.

Celebrations went on for a long time and I was wondering the amount of ammo that was being wasted and I fell sleep, while thinking how crazy the situation we had been through was as well as the futility of wars.

[1] Nick-named the “Popovs” mimicking the sound of the AK47s’ shooting!


As soon as you got closer to Gambela it became clear that you were entering a totally different environment. Located at the confluence of the Baro River and its tributary the Jajjabe, the city was just over 500 metres in elevation, hot and humid with an average yearly temperature of 27°C and 1200mm of annual rainfall (see also:

The bridge over the Baro river at the entrance of Gambela. Credit: T U R K A I R O, CC BY 2.0, via Wikimedia Commons.

At the time, apart from the original Nilotic Anuak and Nuer inhabitants, there were a large number of people from the highlands (Amhara, Oromo, Tigrayan, etc.). Some of them were those who still remained after being brought there by the controversial resettlement schemes being driven by the Government at the time.

These people were moved from their homeland during or after the famine and many, as soon as they could, abandoned their resettlement schemes to get back to their homes, often traveling thousands of kilometers risking the stern measures that they could expect if caught.

The Anuak and Nuer were by far the predominant ethnias. The former built their villages along the banks and rivers of both south-eastern South Sudan as well as south-western Ethiopia. Their population is today estimated between 250 and 300 thousand people. Their subsistence economy largely depended on their rivers as they grew their crops in the riverbanks and they also keep some cattle. During the dry season they fished and hunted the animals that came to drink.

The Nuer are a larger population of about 2 million, concentrated in the Greater Upper Nile region of South Sudan (where they are the second largest ethnic group) and Ethiopia. They are nomadic pastoralists who herd cattle for a living.

An ox being admired for its hide and special horns.

Their cattle serve as companions and define their lives being of the highest symbolic, religious and economic value. So, their lives revolve around their cattle, although some horticulture is also practiced. Their relationship with their cattle is complex and it has been studied by several anthropologists [1] [2].

Although they eat meat and some of their cattle under certain circumstances, their diet primarily consists of fish and millet. We met many of them and most showed long scars in their foreheads. They get these markings (gaar) as part of their initiation into adulthood.

The most common pattern among males consists of six parallel horizontal lines which are cut across the forehead with a razor and applying ash for them to protrude afterwards. Dotted patterns are also common among some Nuer groups and among females. Several of the ethnias in Africa do this and the Dinkas, also from Sudan, also have scars that follow different patterns.

Nuer youngsters and the bushsnob (with a blue cap at the back…).

While travelling in Gambela, the scars on the foreheads were useful to distinguish among Nuer and Anuak and to greet them accordingly: male to the Nuer and dereyote to the Anuak.

We soon learnt that Gambela could be either very dry or very wet, depending of the season. The trip was tough as we usually travel from the Bedele height to Gambela following the curvy murram road behind a convoy of a couple of dozen relief lorries that were almost impossible to overtake safely.

We swallowed lots of dust, an experience I do not wish to repeat, particularly when the hotel in Gambela did not offer the best washing facilities to the disgust of Mabel.

Mabel trying the shower at the Gambela hotel!

Worse than the dust was the black mud during the rainy season and getting badly stuck whilst trying to get to our study cattle was not rare. Getting stuck is usually a nuisance but doing it with a LWB Land Rover demanded lots of work in order to pull it out. In no time, the tire grooves would get stuffed with sticky mud and just turn without gripping anything! Only lifting the wheels would do and, if trees were around, the winch would save us! I noted then that the Nuer would work hard at digging while the job was clearly below the people from the highlands that mostly watched! I had the excuse of being the driver.

Hard at work!
Finally tired but out of the mud!

So, on arrival to Gambela we would find a bungalow at the only hotel suitable for ferengi (foreigners) that offered reasonable rooms and, as I mentioned and showed you above, reasonable showers with muddy water!

Gambela hotel.

Life in Gambela during the hot days happened by the river and we also had the impression that not much mixing between ethnic groups took place, the highlanders staying on one side while the Nilotic would stay in their own river patch.

During the night people came out from their houses and we saw quite a lot of movement in the streets and lots of youngsters, probably Nuer, playing volleyball and basketball in a few fields that were scattered around town. By the way, basketball courts were very common in Ethiopia, probably as common as football fields, probably the influence of past efforts from USA churches?

As some of our Ethiopian veterinary colleagues were educated in Cuba, they knew a number of Cuban human doctors and other technical assistance personnel that were working in the area. We met some of the doctors that had interesting stories to tell and I still remember their amusement when telling us that no operating table was long enough for the Nuer with the consequence that their legs were always sticking out and interfering with their movements!

We also met a young Ethiopian that worked assisting the Anuaks with their fishing activities and, one day we accompany him to his working area nearby to watch people fishing. This was a great experience as we saw the wealth of fish that the Baro river offered.

Among the memories I have was to see some medium size greyish catfish being treated wth utmost respect by the fishermen. When I asked the reason why these were not touched, a fish was placed on one of them and it immediately died! These were electric catfish! I had a good look at them just in case I would hook them in future. These were most likely Malapterurus electricus, a fish found throughout the Nile basin and capable of delivering an electric shock of up to 350 volts that they generate from an electric organ that, in the case of the catfish, runs the entire length of its body [3].

The visit to the fishing community planted the idea in my mind that we could also fish so during the next visit we took one afternoon off and tried to fish. We searched for a spot a distance away from Gambela, trying to avoid the overfished areas near the town, and chose a large rock (away enough from the water) from where we tried our luck for Nile perch or anything that would like to take a chunk of meat. Unfortunately, after a couple of hours we still got nothing and, after watching a few rather large crocodiles swam past, we decided to go back to our hotel before dark.

The Gambela river where we fished.

The crocodiles reminded us again of the dangers lurking in the African rivers and the risks that the local people exposed themselves while living close to rivers. The chain of thought made me remember the story of an American that was taken by a crocodile while entering one of these rivers, but I could not remember where it had happened.

Then I remembered that I had read about this in an amazing book written by Peter Beard called “Eyelids of Morning” that presents a rathe gruesome account of the incident that I thought then had happened in Lake Turkana, the area the book deals with. Once back in Bedele I looked for the story in the book and, to my surprise, the incident had taken place in Gambela!

In 1966, a young Peace Corps volunteer by the name of William Olson had gone to Gambela with a group of colleagues and they decided -unwisely- to go for a swim in the Baro river. Mr. Olson was taken by a rather large crocodile that was later shot and his remains recovered [4]. So it was that we were probably fishing at a spot near where this accident had happened but, luckily, we did not consider a dip in the river despite the intense afternoon heat.

[1] Evans-Pritchard, E. E. “The Sacrificial Role of Cattle among the Nuer.” Africa: Journal of the International African Institute, vol. 23, no. 3, 1953, pp. 181–198. JSTOR, Accessed 15 Nov. 2020.

[2] See:

[3] Electric fish have specialized organs in their bodies, made up of specialized muscle cells called electrocytes. To regulate electrical discharge, they also have a special trigger organ known as the pacemaker nucleus, a specialized group of neurons in the fish’s brain. When the fish wishes to produce an electric current, it triggers the pacemaker nucleus, which sends a signal to the electrocytes initiating electrical discharge.  The electrocytes then use transmitter proteins to move positive sodium and potassium ions out of the cell, building up an electrical charge. The individual amount of electricity generated per electrocyte cell is small. However, when millions of electrocyte cells function simultaneously, an electric fish is capable of building up charges of hundreds of volts… Electric catfish have electric organs that line their entire body cavities. (From: More details on the electric catfish:

[4] See: for a description of the event that spares the gruesome details.

Tick hunting

Our tick (and later tick-borne disease) studies took us to different places of south-western Ethiopia “officially”, so we took advantage of these trips to get to know the area we were living. In our selected sites (Arjo, Bedele, Metu, Gambela and Fincha’a) the project had purchased some cattle from the local farmers, and they were keeping them for us to assess tick numbers at monthly intervals.

Fincha’a was located 295km north of Bedele, after driving through Arjo. This was a long drive that we did a couple of times. At 2300m Fincha’a was a rather cold and also damp place.

Working at damp Fincha’a.

The latter was probably explained by the existence of a dam that, for a while after its inauguration in 1973, was the largest hydro-electric project in the country. The visit I recall took place during the rains and it rained all the time we were there! This did not help our work nor our potential sightseeing!

A shy boy under a reed “raincoat”.

Despite the bad weather, along the road leading to the town we started seeing tall structures built with very long wooden poles and erected by the side of the road. On the top they had a little house and we were very puzzled by them, guessing that they had some religious significance but unsure of their real meaning.

The structures near Fincha’a.

We got to Fincha’a under rain and, while we checked in our rather basic hotel, my colleagues went to arrange for the tick work to be carried out the following day. The hotel was a basic affair to put it mildly with walls that enabled the sounds from the three rooms on each side of us to be heard! However, aware that that was the best hotel (and probably the only one?), we decided to make the best of it.

The hotel did not offer dinner so that we had to venture on the street to find an eating place and we ended up at a small restaurant where we were the only customers! Luckily it was a really warm place both because of the welcome we got from the family that owned it and thanks to the cooking that was taking place inside. Soon, after chasing the chickens away from the room, we joined in the kitchen activities and learnt a few things.

Mabel trying their hand at cooking under supervision.
Dinner arrived.
Mabel grinding the coffee after dinner.

Apart from food-related information, the lady informed us that the tall wooden structures we had seen were erected by local hunters that would travel east towards the Nile to hunt and, on return, they would build these “shrines” where the buffalo skulls would be placed on display to show their ability. I haste to add that I have not been able to confirm this information beyond what I was told at Fincha’a.

We ate hot (both temperature and taste) local food and had a reasonable night sleep. The following morning, we did our work under rain (not a very pleasant activity as the water runs down your back…) and we were soon on our way back to Bedele, looking forward to our warm and dry bungalow.

We also often travelled East, following the B50 road that, at the time, I did not know it had a name! After about 115km from Bedele we arrived at Metu where we did not stop until we discovered that there were some Cuban doctors working at the Metu hospital.

Passing through Metu.
Spices at Metu market.
Assorted goodies.

They were part of the well-known contingent of doctors from the island that are found in many places in Africa, often in areas that no one else wishes to be! We learnt that among them many specialities were covered and this boosted our confidence in case of a health problem as the facilities that existed in Bedele were rather limited. Luckily, we only visited them socially and we did not need their services.

Their presence was clearly justified judging by the number of people suffering from serious diseases that we found on the road. Apart from the blind being led by holding sticks by young relatives, many young boys and girls showed cases of tinea (ringworm) and scabies. These were mostly treated with Gentian violet with the consequence of lots of purple-stained heads around! Goitre was rather common and even severe cases of elephantiasis could also be seen.

Following the road to the south-east we would come to Gore, a larger town that became known as it was the capital of Ethiopia for a short while. It happened during the Italo-Ethiopian war fought between 1935-1937. In 1935, the Italians attacked from their colonies of Eritrea and Somalia without declaring the war. After conquering Aduwa, they seized Aksum [1] and then moved on Addis forcing Emperor Haile Selassie to leave the country (taking the gold of the Ethiopian Central Bank with him!).

Before leaving he ordered that the capital of Ethiopia to be moved to Gore and appointed his cousin Ras Imru Haile Selassie as Prince Regent during his absence. The latter fell back to Gore to reorganise and continue to resist the Italians but his efforts were fruitless and Gore was occupied at the end of 1936. Ras Imru, with his forces trapped between the Italians and the Sudan border surrendered and he was flown to Italy and imprisoned on the Island of Ponza. So that was Gore’s claim to fame although the town did not have much to show for its history.

Leaving Gore behind, we would drive another 150km west on a wide, dusty and mostly downhill road full of curves following the course of the Baro river towards the Sudan border. The road offered magnificent scenery where we often stopped to stretch our legs and have a look a the rather clean waters of the river.

The heavy relief lorry traffic aiming for the refugee camps in the border with Sudan did not help our progress. Going towards the refugee camps in the Gambela area loaded, they would come back with the trailers “piggy-backed” on the same tracks, the first time I saw this really clever saving technique.

Eventually, full of dust and rather edgy with the road and its traffic, after crossing a large bridge over the Baro river, we would arrive to the town of Gambela, a completely different seen when compared with where we were coming from as Gambela, at 526m was a tropical area, particularly when arriving from Bedele located at almost four times that height!

The bridge over the Baro river in Gambela. Credit: T U R K A I R O / CC BY (

Gambela, located at the confluence of the Baro river and its tributary the Jajjabe was founded because of its location on the Baro river, a tributary of the Nile, which was seen by both the British and Ethiopia as an excellent highway for exporting coffee and other goods from the fertile Ethiopian Highlands to Sudan and Egypt.

Already while crossing the river it was apparent that everything was different but most of all the people that inhabited the area. Although there were some from the highlands, most of them as a result of the ruthless resettlement schemes, this was the territory of the Anuak and the Nuer, people that we had not seen before in the country.

The Anuak belong to the Luo Nilotic ethnic group. They are primarily found in villages situated along the banks and rivers of southeastern South Sudan as well as southwestern Ethiopia, especially the Gambela Region. Group members number between 250,000 and 300,000 people worldwide, many of them following Christianity. The Anuak are an agricultural people, although most families keep some livestock. They are keen on fishing and they set up temporary fishing villages in times of fish abundance.

Anuak fishing in the Baro river.

The Nuer are also of Nilotic origin and inhabit a similar area than the Anuak. Their language belongs to the Nilotic language family and they are closely related to the better known Dinka ethnic group. They are pastoralists who herd cattle and the cattle define their way of living.

Both races are very tall [2] and we often watched them in amazement playing basketball at night (too hot during the day) in the local open courts in Gambela thinking that they would be sought after by the National Basketball Association (NBA) and not knowing that they had done so. Manute Bol, a Dinka of 2.30m (one of the tallest players in the history of the NBA), had been playing for the Washington Bullets since 1985!

About to start working. The picture shows a rather tall gentleman on the right!

The Nuer receive facial markings (called “gaar”) as part of their initiation into adulthood. These consist of scarification that varies within their subgroups, the most common among men being six parallel horizontal lines cut across the forehead although dotted patterns are also common. The scarifications helped me to distinguish people from the two groups and enabled me to greet them properly in their language, “male” to the Anuak and “derejote” to the Nuer.

I will come back with more experiences from Gambela in future posts.

[1] Italian soldiers found one of the Axum obelisks (stelae) (King Ezana’s) fallen and broken in three sections, one of about fifty obelisks in the city of Axum at the time of the discovery. In 1937, it was taken as war booty and moved to Italy after being cut into five pieces and transported by truck to Massawa from where it was shipped to Naples. It was then taken to Rome, where it was restored and erected in front of the Ministry of Italian Africa (later the headquarters of the FAO) where I saw it (pic is already in Media and I found it looking for Rome). It was eventually returned to Ethiopia in 2005.

[2] See: Chali, D. (1995).  Anthropometric measurements of the Nilotic tribes in a refugee camp. Ethiopian Medical Journal 33: 211-7. Among other things, the study concludes that “…The mean height of Dinka men (176.4 +/- 9 cm) and Nuer men (175.7 +/- 9 cm) were significantly higher than that of Anuak men (171.7 +/- 8 cm) and Shilluk men (172.6 +/- 6.1 cm). This study confirms that the Nilotics in Southern Sudan have slender bodies and are amongst the tallest in the world and may attain greater height if privileged with favourable environmental conditions during early childhood and adolescence, allowing full expression of the genetic material…”