The study was conducted in rural areas in the agroecological zones of the Center, Center-West, Northwest, and Northeast of Côte d’Ivoire. The choice of these areas is justified by the fact that they are the main breeding areas for N’Dama bulls. The Marahoué ranch has the largest population of purebred N’Dama cattle.

The agroecological zone of the Centre, covered 4 administrative localities (Bouaké, Brobo, Toumodi and Dimbokro) of three regions (Gbêkê, Bélier, N’Zi). This part of the country has a relatively flat relief, with a succession of high plateaus known as the Baoulé Chain. The vegetation is composed of wooded savannah, grassland savannah and mesophilic gallery forests along the watercourses. The hydrographic network of the Centre is mainly made up of the Bandama river and its tributary the N’Zi. There are also lakes and rivers [10] . In the Center of the country, rainfall is less abundant (from 1000 to 2500 mm).

The Northwest region covers the administrative districts of Ouaninou and Touba in the Bafing region, and Sipilou in the Tonkpi region. The Bafing region is crossed by rivers and the relief is made up of mountains, plateaus, valleys and plains. The vegetation consists of a transition zone straddling the forest and the savannah. The annual rainfall is around 1127 mm. The region has a humid tropical Sudano-Guinean climate. Its rainy season runs from April to October and the dry season from November to March . The Tonkpi Region is located in the far west in the mountain district. In this region, the series of lowlands is linked in places with very rugged areas with contours varying between medium slopes and altitudes sometimes exceeding 1000 m . Rainfall levels vary between 1300 and 2400 mm per year. Temperatures are mild and average 24˚C. The Tonkpi region is irrigated by the Sassandra river in the east and the Cavally river in the west, each with numerous tributaries that promote vegetation consisting of 80% rainforest .

The Northeast region covers the Bouna department in the Bounkani region. The Bounkani region exhibits a very pronounced geomorphological diversity. The peaks of the ridges, often blunt, can reach 700 meters high . The region, once made up of grassy and wooded savannahs, is now heavily shrubby, with gallery forests along the region’s rivers and streams. Comoé park made up of savannahs and open forests with an area of 11,090 km² covers almost half of the territory. The region has a Sudanese climate. It is characterized by a dry season that runs from November to March, a rainy season that lasts from April to October, and a harmattan that lasts from November to February . The region is bordered to the west by the Comoé river and to the northeast by the black volta river.

Created in 1975, the Marahoué ranch’s mission is the selection, multiplication, conservation and distribution of N’Dama cattle only. It is located in the center-west of Côte d’Ivoire between the Worodougou and Béré regions. The vegetation is a savannah with Andropogon macrophylles on the plateaus with dense forests and gallery forests along the Marahoué River and its tributaries. The vegetation is being invaded by woody and thorny plants (Solannum verbacifolium, Harungana madagascariensis, Trema guineensis, Dicrostakis gomerata, Acacia ataxacantha, Mimosa pigra) [12] . The climate is Baoulean with a long rainy season (from March to June) and a long dry season (from July to August). The average annual rainfall is 1182 mm [13] .

Through documentation and support from agents of the Ministry of Animal and Fisheries Resources, the N’Dama cattle breeding areas in Côte d’Ivoire were determined. These are the Northwest region which borders Guinea (cradle of the Guinean type N’Dama), the Central region which concentrates the majority of N’Dama cattle improvement projects, the Northeast region where the N’Dama is used in plantations and the Marahoue ranch. The accessibility of the farms, the availability of breeders and the size of the herd were the criteria for selecting the farms. The size of the herds ranged from 15 to 50 head of N’Dama cattle.

In real livestock farming, cattle led by herdsmen travel long distances in search of pasture. They are very often in conflict with farmers. The animals are periodically distributed salt and not given any vitamin supplements. At nightfall, they return to the camp where they are kept in night pens. The animals are most often cared for by the herdsmen themselves. Most of the animals do not receive any external deworming. Internal deworming of cattle is the most common practice on these farms. As for the Marahoué ranch, the animals are led to pasture, to water, and to night pens every day from 8 a.m. to 4 p.m. The Marahoué river and its tributaries, are the watering sites for the herds. During the dry season, the animals’ feed is supplemented with cottonseed. The animals are treated weekly during the rainy season and fortnightly during the dry season. They are treated for external parasites with Aphacypermethrin. Internal deworming is mostly performed on young animals.

The phenotypic description of N’Dama cattle was carried out in two phases. A total of 201 cattle, including 22 males and 179 females aged four years and older, were sampled. The first phase took place from December 2016 to January 2017 in rural areas in the regions of Bafing, Gbêkê, N’Zi, Bélier and Tonpki. This part of the data has been the subject of a previous study carried out by [3] . The second phase took place from January to February 2024 at the Marahoué ranch and then in farming system in the Bounkani region. Qualitative traits such as ear orientation, eyelid color, muzzle color, coat color, back profile, horn orientation, presence of frontal spot and dewlap development were the variables used to describe the cattle. Each animal was observed once and described using these qualitative variables with the naked eye. The age of the animals was determined based on their dentition and the number of striations on their horns ( Table 1 ).

Data were entered into Excel 2016 software. Variable modalities were expressed as percentages. The chi-square goodness-of-fit test was used to compare the proportions between the different modalities of a variable in order to determine which modalities, appear frequently in each type of system. A multiple correspondence analysis (MCA) was performed to verify the segregation of individuals in a factorial design based on categorical variables. The optimal number of groups was determined using fastcluster software. The typology of these different groups was performed by crossing the most discriminating variables, the system variable and the group variable, using a Chi-square test. The significance level used for the interpretation of statistical tests is 5%. All analyses were performed using R 4.4.2 (R Core Team, 2024) and XLSAT 2024 software.

Table 2 shows the frequencies of occurrence of qualitative trait modalities production system. The N’Dama described in this study shows phenotype variability for all descriptors. It has a coat of various colors (fawn, white, sandy, gray and black), five different horn shapes (lyre, crescent, cup, crown, back), three phenotypes describing the profile of the back (straight, concave, convex), and two modalities for the rest of the characters ( Figure 1 , Figure 2 and Figure 3 ). The Chi-square test comparing the different proportions of the modalities tells us that some phenotypes are more frequent than others (p < 0.001). Thus, in the general study population, the N’Dama frequently has a fawn-colored coat (83.1%), ears carried horizontally (95.1%), lyre shaped horns (44.3%), a straight back (87.1%), unpigmented eyelids (75.1%), bicolored horns (86.6%) and is without a forehead spot (94.5%). Specifically, the N’Dama from the farming environment has, in addition to the fawn-colored coat (68.2%), other types of coat color (piebald-black, black, white, grey) at 31.8%. They have all types of horn, but mostly lyre horn (58.9%). Some subjects in this population have pigmented eyelids (39%) and others do not (61%). In this population, the N’Dama has a straight, concave and convex back at frequencies of 75.7%, 15.8% and 8.4% respectively. It has bicolored horns and horizontal ears in general (91%). The N’Dama from the Marahoué ranch, on the other hand, has only a fawn-colored coat (100%), a straight back (100%), and ears carried horizontally (100%). Like the farming system N’Dama, the N’Dama from the ranch has all horn types, but in roughly equal proportions. It has mostly eyelids (91.5%) and an unpigmented muzzle (91.5%). In particular, all the cattle on the ranch with pigmented muzzle have pigmented eyelids (8.5%). Those with unpigmented muzzle also had unpigmented eyelids (91.5%). Dewlap is medium and low in 43.6% and 56.4% of cattle in this system respectively.

The values outside the braquets represent the number of cattle. The values inside the braquets represent the frequencies (%). Fawn* = ginger fawn, wheaten fawn, red fawn; Other color* = piebald-black, black, white, grey, sand; χ² = Chi-square; p = probability; df = degree of liberty; Other shape* = crown, back; Bi-colour* = black and white; unicolour* = black, white; T. system = traditional system.

Multiple correspondence analysis (MCA) was used to determine the factors of morphological variability in N’Dama cattle according to qualitative variables. The results of this analysis show that factor 1 alone summarizes 64.44% of the information contained in the study population ( Table 3 ). Factor 1 allows us to qualitatively differentiate cattle through four variables. These variables are coat color (Rbe), horn shape (Fcn), eyelid color (Cpp) and muzzle color (Cmu). Eyelid color, with a contribution of 33.88%, is the most important in defining factor 1 followed by muzzle color (30.70%), coat color (24.48%) and horn shape (10.2%). Factor 1 therefore described cattle according to eyelid, muzzle and coat color. It also identifies them to horn shape. The modalities fawn coat (Rbe-1), other coat color (Rbe-2), unpigmented muzzle (Cmu-1), pigmented muzzle (Cmu-2), unpigmented eyelids (Cpp-1), crescent-shaped horn (Fcn-2) and pigmented eyelids (Cpp-2) are well represented on the factor. Axis 1 therefore perfectly explains the variability brought about by these modalities. With negative test values significantly different from zero (p < 0.05), the tawny coat (−3.835), unpigmented muzzle (−4.295) and unpigmented eyelids (−4.512) characters form a group of variables at the extreme left of the factor. Opposite this variable group, the characters other color type coat (3.835), crescent-shaped horn (2.371), pigmented muzzle (4.295) and pigmented eyelids (4.512) also form another variable group ( Figure 4 ). Fawn-colored N’Dama therefore tend to have unpigmented muzzles and eyelids. N’Dama with other coat colors (piebald-black, black, white, grey) tend to have crescent-shaped horns and pigmented muzzles and eyelids.

Cos2: square cosine; The values in bold represent the Cos2 and the largest contribution, F: factor.

Determination of the optimal classes was performed with a partitioning algorithm using the higher inertia relative loss criteria method. Figure 5 shows the inertia jumps obtained from the transformation of the categorical variable matrix into hclust class objects. Analysis of this figure shows that the optimum number of hierachical groups is two. Cross-referencing these groups with the overall study population gives us the composition of each group ( Table 4 ). Figure 6 shows the projection of these groups in the factorial plane of the MCA (F1; F2). Group 1, located in the negative part of axis 1, is made up of 153 N’Dama cattle. The second group, opposite group 1, comprises 48 cattle. The factors farming system had a significant effect on group formation (p < 0.001). Group 1 comprises 65 cattle from the farming environment (42.48%) and 88 cattle from the Marahoué ranch (57.51%). The second group comprises 42 cattle from the farming system (87.5%) and 6 from the ranch (12.5%). The most discriminating variables determined by the MCA all had significant effects on the variation of individuals in the different groups ( Table 3 ). The first group is made up of N’Dama with fawn-colored coats (96.73%), lyre-shaped horns (49.67%), unpigmented eyelids (97.38%) and unpigmented muzzles (90.1%). The second group is characterized by N’Dama with piebald-black, black, white, and grey coat color (60.41%), and crescent horns (52.08%). Their eyelids are pigmented (95.83%), as is their muzzle (97.91%).

The values outside the braquets represent the number of cattle. The values inside the braquets represent the frequencies (%). Fawn* = ginger fawn, wheaten fawn, red fawn; Other color* = piebald-black, black, white, grey, sand; df = degree of liberty; p = probability; Other shape* = crown, back; Bi-colour* = black and white; unicolour* = black, white; T. system = traditional system; % = percentage.