Performance, biosecurity practices and antimicrobial usage in Montbéliarde dairy farms in Northern Cameroon

Abstract

To improve local milk production, the Cameroonian government re-imported Montbéliarde heifers from Europe through a World Bank-funded project. This study aimed to assess the performance of Montbéliarde cows distributed in Northern Cameroon, as well as biosecurity implementation and antimicrobial use (AMU) among the beneficiary farms. Data were collected in all the farms that agreed to participate. In total only 75% (48/64) of farms that received Montbéliarde were still operating one year after the end of the project. The rest (16/64) reported to having sold their animals due to the high feed costs and challenges related to animal health management. In addition, the average daily milk production per cow was estimated at 9.1 ± 3.1 kg (95% CI: 7.4–11.6). Only 38.2% of farms had a good level of biosecurity compliance. Biosecurity measures relating to health and calving management were the least implemented. The majority of participants had limited knowledge of AMU (76.5%) and antimicrobial resistance (91.2%). Moreover, more than 90% of antibiotics were overdosed during cattle treatment. These findings highlight a serious concerns in terms of the sustainability of importing Montbéliarde cows. The authors recommend that the government urgently implement measures such as subsidize the feed/drug, and train farm workers on cattle management and AMU.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-026-50197-8.

Background

Livestock farming plays an important socio-economic role, contributing significantly to the development of many countries around the world¹. Among livestock products, the demand and production of milk continue to increase rapidly due to population growth, rising incomes, changing lifestyles and diets. Cow milk dominates this sector, accounting for 81% of total production². World milk production is projected to grow faster than other agricultural commodities at a rate of 1.6% per annum by 2032^3,4. In Africa, dairy production is vital for generating income and serves as a fundamental component of food security, and cultural identity^5–7. In 2021, the total milk production in Africa was about 50 million tons, representing approximately 6% of global milk production⁸, while the gross production value of raw cattle milk was estimated at over USD 14 billion⁹.

In Cameroon, dairy production is particularly important, contributing over 17% to agricultural Gross Domestic Product¹⁰. Milk is not only an essential product but also an important source of income for the Cameroonian population¹¹. However, local cattle breeds are characterized by low milk production (1.4 to 2 L/cow/day)¹². This is not only due to genetics but also to poor dairy farm management practices. Poor management practices increase the occurrence and spread of infectious diseases such as foot-and-mouth disease, bovine trypanosomosis, and mastitis, which have a serious impact on milk production^12–15. The milk production deficit was estimated at 170,000 tons per year¹² which necessitate the importation of milk products, leading to a considerable drain on financial resources. This results in significant losses to the national economy. Therefore, increase national milk production is essential to reduce these losses.

To improve local milk production, in 2016, the Cameroonian government decided to re-import Montbéliarde heifers from Europe through a major World Bank-funded livestock project. This was done nearly a century after (1934) the first introduction of Montbéliarde cattle in Cameroon during the colonial period¹⁶. This decision may have been based on several factors. First, the growth of the dairy industry in many African countries has been partly attributed to cross-breeding programs^9,17. Second, the Montbéliarde breed may has been selected for its robustness, and resilience in various environments^18,19, as well as its good fertility. Additionally, cross-breeding with other dairy breeds can improve resistance and fertility²⁰. Furthermore, the Montbéliarde breed is one of the most productive dairy cattle breeds in the world with an estimated production of 6,000 kg of milk/lactation²¹. The milk produced by the Montbéliarde is of high quality in cheese dry matter (higher fat/protein ratio)²⁰. A total of 493 Montbéliarde cattle were imported and distributed throughout the country.

Beneficiaries who received Montbéliarde cattle from 2021 under the above-mentioned project have been trained on different topics related to dairy farming (dairy farm management, artificial insemination, health management, etc.). In addition, they received financial supported. The training also included the implementation of biosecurity in dairy farms. Biosecurity plays a crucial role in preventing and controlling livestock diseases, leading to improved animal health, and increased productivity and economic sustainability of farms^22–24. This is especially true in dairy farms, where infectious diseases can significantly reduce milk production.

Three years after receiving Montbéliarde cattle, and one year after the end of the project, this study was conducted to evaluate the performance of Montbéliarde cows distributed to farmers in the Northern regions of Cameroon, as well as biosecurity compliance and antimicrobial use (AMU) among the beneficiary farms. .

Results

Socio-demographic characteristics of respondents

Of the 64 commercial farms that received Montbéliarde cattle in the study area, 48 (75.0%) were still operating during the study period, of which 34/48 (70.8%) were surveyed for biosecurity, and AMU: 26 (76.4%) in the Adamawa, 4 (11.8%) in the North, and 4 (11.8%) in the Far North regions. According to the available data, six and eight farms received the Montbéliarde cattle in the North and Far North regions, respectively. Fourteen (25%) farmers refused to take part in the study. Among them (14/48), the majority reported that they had sold their cattle and the rest said that their animals had died. Among the 34 farmers who agreed to participate in this study, the majority were male (32/34) and aged 30–39 years old (12/34). More than half of the participants had secondary level of education (23/34) and had received training in livestock farming (20/34). Most of the respondents (29/34) had more than 10 years of cattle farming experience (Table 1).

Table 1.

Socio-demographic characteristics of farmers in the study regions (n = 34).

Variable	Number	Percentage (%)
Age (years)
30–39	12	35.3
40–49	11	32.3
≥ 50	11	32.4
Gender
Male	32	94.1
Female	2	5.9
Educational level
Informal	4	11.8
Primary	5	14.7
Secondary	23	67.6
University	2	5.9
Training in livestock farming
Yes	20	58.8
No	14	41.2
Experience in cattle farming (years)
3–5	2	5.9
6–10	3	8.8
> 10	29	85.3

Cattle farm characteristics

Table 2 provides an overview of the farm characteristics. The majority of farms (29/34) visited had received 2 to 5 Montbéliarde heifers. At the time of the survey, most of the farms (17/34) had between 1 and 5 Montbéliarde cows. More than half of the farms (19/34) had a mixed herd containing other cattle breeds (Holstein and local breeds) in addition to Montbéliarde. Slightly more than one-third of farms had a veterinarian (13/34) who was in charge of animal health. According to the contracts between farmers and veterinarians, the majority (67.7%) mainly intervened in case of problems. Most of the farmers (20/34) reported feed as the main constraint for Montbéliarde rearing. In the dairy farms visited, digestive diseases such as gastroenteritis were the most frequently reported diseases in Montbéliarde breed in all the regions of the study. This category of disease was reported in 70% of the farms visited. Other animal diseases such as mastitis (23.5%), foot and mouth disease (11.8%), trypanosomiasis (8.8%), and contagious bovine pleuropneumonia (8.8%) were also reported by farmers. All the farmers were able to identify the symptoms associated with these diseases.

Table 2.

Characteristics of cattle farms in the Northern regions of Cameroon (n = 34).

Variables	Number	Percentage (%)
Number of Montbéliarde received
2–5	26	76.5
6–9	3	8.8
≥ 10	5	14.7
Number of Montbéliarde cows in the farm
1–5	17	50.0
6–10	9	26.5
>10	8	23.5
Other dairy breeds present in the farm
None	15	44.1
Holstein	8	23.5
Local breeds	2	5.9
Both Holstein and local breeds	9	26.5
Person in charge of animal health in the farm
Veterinary doctor	13	38.2
Veterinary nurses	8	23.5
Veterinary doctors and nurses	1	2.9
Livestock technician	11	32.3
None	1	2.9
Frequency of visit of the health specialist in the farm
1–2 visits/month	10	30.3
3–4 visits/month	1	3.0
In case of problem	22	66.7

Performance of Montbéliarde cattle

The average age at first calving of cows in the study area was 2.44 ± 0.25 years (95% CI: 2.40–2.50), with a gestation length of 272.56 ± 15.01 days (95% CI: 269.01-276.12). In general, the average daily milk production per cow was 9.1 ± 3.1 kg (95% CI: 7.40–11.60). The quantity of milk produced (14.0 ± 4.9 kg) in the Far North region was significantly (p = 0.01) higher than that of the other regions (9.9 ± 3.7 kg and 8.3 ± 2.8 kg in the Adamawa and North regions, respectively). The daily production during the first month (9.4 ± 1.8 kg) was significantly (p < 0.05) higher than in the second (8.9 ± 1.6 kg) and third month (8.1 ± 1.6 kg). The maximum milk production recorded was 21.1 kg per day. The mean BCS recorded was 2.6 and no variation was observed according to the region. More than a quarter (27.7%) of the farms surveyed reported having had at least one abortion since receiving the Montbéliarde animals (Table 3).

Table 3.

Performances of Montbéliarde cattle in the Northern Regions of Cameroon.

Variables	Adamawa	North	Far North	Total
Age at first calving (year)	2.48 ± 0.26	2.41 ± 0.22	2.32 ± 0.13	2.44 ± 0.25
Gestation length (days)	273.50 ± 12.76	266.28 ± 14.56	276.50 ± 10.61	272.56 ± 15.01
Initial milk production (kg)/day	9.9 ± 3.7	11.5 ± 3.8	14.0 ± 4.9	10.4 ± 3.9
Maximum milk production (kg)/day	19.6	19.3	21.1
Daily milk production/cow (kg)**	9.2 ± 3.0	8.3 ± 2.8	14.2 ± 3.2	9.1 ± 3.1
Body condition score	2.7 ± 0.6	2.5 ± 0.5	2.50 ± 0.5	2.6 ± 0.6
Weight of cattle (kg)
1–3 years (n = 90)	247.5 ± 83.5	208.0 ± 3.8	208.01 ± 3.8	239.6 ± 69.1
> 3 years (n = 140)	582.1 ± 77.6	614.3 ± 42.2	621.0 ± 34.3	587.8 ± 74.4

**P < 0.01. Each value represents the mean ± the standard deviation. Data about body condition score and cattle weight were collected from 159 cows of the 34 farms while the rest of data concerned 71 cows of 6 farms having the record of daily milk production per cow.

Level of biosecurity in cattle farms

Less than half (38.2%) of the 34 farms visited had a good biosecurity level (≥ 50%). More farms in the North region (50.0%) compared to the Adamawa (38.5%) and Far North (25.0%) regions had a good level of biosecurity. Overall, the total biosecurity mean score of the farms that received Montbéliarde cattle in the Northern regions of Cameroon was 45.7% (SD = 7.3), with a median of 46.5% and a range of 27–58% (Table 4). The mean score of internal (25.4% range 14–42%) was lower than external biosecurity score (64.2% range 39–78%). Among the different subcategories, biosecurity measures relating to 'health (mean score 7.9%) and calving (mean score 11.9%) management were the least applied by farmers, while the highest mean scores were observed for ‘purchase and reproduction of cattle’ (mean score 91.5%), followed by ‘visitors and farmworkers’ (mean score 66.9%). Concerning the variation of biosecurity according to interviewers’ profiles (Table S1, Supplementary material 2), or farm characteristics, a significant difference (p < 0.05) was only found between external score of farms managed by respondents who had received training in livestock rearing (mean score 61.4%) and those who had not (mean score 70.0%).

Table 4.

Biosecurity score (%) in farms that received Montbéliarde cattle in the Northern Regions of Cameroon.

Variables	Mean	SD	Median	Min	Max
Total external biosecurity score	64.2	11.7	69.5	39	78
Purchase and reproduction	91.5	17.3	100.0	40	100
Transport and carcass removal	36.6	8.2	36.0	20	54
Feed and water	37.3	9.5	35.0	0	55
Vistors and farmworkers	66.9	14.7	66.0	42	92
Vermin control and other animals	51.4	13.0	56.0	20	70
Total internal biosecurity score	25.4	7.4	0.24	14	42
Health management	7.9	15.2	0	0	57
Calving management	11.9	7.0	11.5	0	26
Calf management	26.7	8.9	27.0	11	44
Dairy management	39.4	11.0	43	12	58
Adult cattle management	51.8	17.4	50	27	70
Working organization and equipment	58.3	23.3	69	17	75
Overall biosecurity score	45.7	7.3	46.5	27	58

SD : Standard deviation ; Min : Minimum ; Max : Maximum.

Farmers’ knowledge concerning AMU and AMR

In general, less than a quarter of farmers in the study area had good knowledge (score ≥ 50%) concerning AMR (23.5%) and AMU (8.8%). In the North and Far North regions, all the farmers had insufficient knowledge about AMR. The overall mean AMU and AMR knowledge scores of farmers were 33.6% (range 0-100) and 16.6 (range 0-100), respectively. Farmers with a higher level of education had a significant (p < 0.001) higher AMU knowledge score (85.3%) than the others (Table S2, Supplementary material 2). All the farmers reported using antibiotics to treat viral diseases in cattle. Less than one-third (29.4%) of farmers were aware of AMR, and 20.6% recognized that AMU for preventive purposes could lead to AMR development. Only 2.6% of respondents agreed that using the same antimicrobials for a long time could cause AMR (Fig. 1). Concerning AMR, farmers aged between 60 and 69 years had a statistically (p = 0.002) lower average score (0%) than the others (Table S3, Supplementary material 2). In addition, even with an insufficient knowledge level, farmers who had received training in livestock rearing had a significantly (p = 0.031) higher mean score (25.9%) than those without training (4.76%).

Fig. 1.

Farmer’s knowledge about antimicrobial resistance (AMR) in the Northern Regions of Cameroon. AMU: antimicrobial usage.

Farmers’ practices concerning AMU

All the farmers surveyed had a good level of AMU practices. The overall mean score of AMU practices was 87.4% (range 78.1–90.4). There was a significant variation in the level of AMU practices according to the region (p = 0.031) and the age (p = 0.004) of the respondents (Table S4, Supplementary material 2). Farmers of the North region scored significantly higher than others (90.4%). Almost all the farmers (97.2%) admitted to continuing selling milk even when cattle were under antibiotic treatment.

Antimicrobials frequently used in farms surveyed

Overall, 12 commercial antibiotics containing 10 different active substances (AS) belonging to 6 classes of antibiotics were used in the farms visited in the Northern regions of Cameroon. All these drugs were administered to cattle through the intramuscular route. The majority of treatments were administered to treat digestive (53%) and respiratory diseases (39%) disorders. A total of 51 AS were used in the 34 farms during the six months preceding the survey. The majority of drugs used had one (83.3%) or two (16.7%) AS. Oxytetracycline (33.3%) was the most frequently AS used followed by ceftiofur (27.4%), spiramycin (11.8%), penicillin (9.8%) and sulfate dihydrostreptomycin (9.8%). Tylosin, trimethoprim, and sulfamethoxazole were only used by farmers in the Far North region, while spiramycin was only used in Adamawa. Ceftiofur was used by 86% of farmers in Adamawa and 14% of farmers in North. Oxytetracycline, dihydrostreptomycin and penicillin were used in all the study regions. In terms of class of antibiotic used, macrolides (28.6%) was the most commonly used, followed by beta-lactams (16.6%), aminoglycosides (16.3%), and tetracyclines (15.6%). According to WHO categorization, 47.1% of the AS were categorized as HIA while 52.9% were classified as critically important for human medicine, with 25.5% of CIA and 27.4% of HPCIA.

Quantitative antimicrobial use

The quantity of antibiotics used in cattle farms, expressed as Defined Daily Dose (DDD) and Used Daily Dose (UDD) is presented in Table 5. Oxytetracycline, representing more than half of the antimicrobial used (53.4%) was the most frequently used antibiotic, followed by spiramycin (12.8%), penicillin (10.3%), and dihydrostreptomycin (10.0%). In terms of dosage, HIA (65.9%) was the main group of antibiotics used. CIA and HPCIA represented 28.2% and 5.9%, respectively. Based on the UDD to DDD ratio, almost all the AS (96.1%) were misused, with 90.2% overdosed (Table 5). Only sulfamethoxazole and trimethoprim were correctly dosed.

Table 5.

Daily dosages (mg/kg), dosing ratios and total amount of antimicrobials used (g) in visited dairy farms in the Northern Regions (Cameroon).

Antimicrobial class	Active substance	DDD (mg/kg)	UDD (mg/kg)	UDD/DDD	Total used [g (%)]
HPCIA					144.0 (5.9)
Cephalosporine	Ceftiofur	1.0	8.2	8.2	144.0 (5.9)
HIA					1 615.8 (65.9)
Beta-lactam	Penicillin	8.0	35.3	4.4	252.0 (10.3)
Tetracycline	Oxytetracycline	14.2	37.7	2.6	1309.8 (53.4)
Sulphonamides Diaminopyrimidines	Sulfamethoxazole	20.0	21.2	1.1	45.0 (1.8)
	Trimethoprim	4.0	4.2	1.1	9.0 (0.4)
CIA					693.0 (28.2)
Macrolides	Spiramycin Tylosine	9.4 10.0	35.3 38.8	3.8 3.9	315.0 (12.8) 132.0 (5.4)
Aminoglycosides	Dihydrostreptomycin	8.0	19.8	2.5	246.0 (10.0)

Defined Daily Dose (DDD), Used Daily Dose (UDD), Underdosing: UDD/DDD < 0.8; correctly dosing: 0.8 ≤ UDD/DDD ≤ 1.2; overdosing: UDD/DDD > 1.2, HPCIA: highest priority critically important antimicrobials, CIA: critically important antimicrobials, HIA: highly important antimicrobials.

All the critically important antibiotics for human medicine (CIA and HPCIA), as well as 79.2% of HIA, were overdosed (Table 6). In total 46 out of 51 treatments administered to animals were overdosed.

Table 6.

Correctness of dosage (ratio UDD/DDD) of antibiotics used in cattle farms.

Active substance	Total number of treatments	Underdosing (%)	Correctly dosing (%)	Overdosing (%)
Ceftiofur hydrochloride	14	0	0	14 (100)
Oxytetracycline chlorydrate	1	0	0	1 (100)
Sulfate dihydrostreptomycin	5	0	0	5 (100)
Oxytetracycline	13	1 (7.7)	0	12 (92.3)
Dihydrate oxytetracycline	3	2 (66.7)	0	1 (33.3)
Penicilin G procaine	5	0	0	5 (100)
Spiramycin	6	0	0	6 100)
Sulfamethoxazole	1	0	1 (100)	0
Trimethoprim	1	0	1 (100)	0
Tylosine	2	0	0	2 (100)
Total	51	3 (5.9)	2 (3.9)	46 (90.2)

Underdosing: UDD/DDD < 0.8; correctly dosing: UDD/DDD within the range of 0.8 and 1.2; overdosing: UDD/DDD > 1.2.

Relationship between AMU and farmers’ knowledge of AMU and AMR

Results showed a significant (p = 0.007) moderate negative correlation (r = − 0.481) between farmers’ knowledge of AMR and the quantity of antibiotics used. However, no correlation was found between the quantity of antibiotic used and farmer’s knowledge of AMU.

Effect of biosecurity on antibiotic use and performance

The quantity of antimicrobial did no different significantly (p > 0.05) between farms with good and poor biosecurity level. Nevertheless, the quantity of antibiotics used in farms with poor biosecurity remained slightly higher (27.8 mg/kg) than the others (24.8 mg/kg). Data analysis did not show a correlation between the quantity of milk produced by Montbéliarde cows (p > 0.05, r = 0.11) or the mortality rate (p > 0.05, r = − 0.11) and the biosecurity level of the farms. The correlation analysis performed did not indicate an association (p > 0.05) between farmers’ knowledge of AMU and biosecurity implementation in their farms. A significant (p < 0.05) moderate negativecorrelation (r = − 0.40) between biosecurity and BCS was also found in the study area.

Discussion

To increase milk production to meet population demand, the Cameroonian government re-imported Montbéliarde cattle which were distributed in different batches to farmers throughout the country. The majority of these cattle (80%) were distributed in the Northern regions (North, Adamawa, and Far North). hree years after the distribution of the first batch of animals and one year after the end of the project, this study was conducted to evaluate the performance of the cattle imported and assess the biosecurity practices and their relationship with AMU in the beneficiary farms.

The results showed that only one year after the end of the project, out of the 64 farms that had benefited from the Montbéliarde cows in the Northern regions, only 75% were still operating. This finding highlights a serious problem regarding the sustainability of the project in term of milk production. In fact, despite the support provided to farmers, they still continued to experience substantial difficulty in rearing the Montbéliarde breed. This is due to the constraints associated with this cattle breed, which requires significant investment in terms of nutrition and health management compared to local cattle breed they usually rear. All this could suggest that the targeted objectives of the government to increase local milk production and reduce importation of dairy products may not be achieved. This could also be the result of the limited inclusivity or a lack of an interdisciplinary approach during the design and the implementation of the project under which Montbéliarde cattle were imported.

The average age at first calving of Montbéliarde cows recorded in this study was 2.44 ± 0.25 years (95% CI: 2.40–2.50). A similar result was reported in Morocco⁴⁰ where the age at first calving of Montbéliarde was 2.5 years. This age falls within the range of favorable age at first calving (2.2–2.5 years) for the best lifetime performance of the Montbéliarde. Indeed, first calving between this range results in a better production and productivity performances such as daily milk yield, lactation persistence, length of life, productive life, and lifetime milk yield⁴¹. The average age at first calving of the Montbéliarde cattle breed was estimated at 2.9 years in Algeria⁴² and 2.6 years in Bulgaria⁴³. The divergence with our results could be explained by the variation in rearing systems, health management, and animal nutrition.

The average daily milk production per Montbéliarde cow was estimated at 9.1 ± 3.1 kg (95% CI: 7.4–11.6) in the study area. This production is lower than the 17.5 kg of daily milk per cow anticipated when importing this breed. This low production is likely due to poor quality of feed given to animals in addition to the poor animal health reflected in the recorded suboptimal health management. Farmers in this study pointed out feed supply as the major constraint in Montbéliarde rearing. In Algeria, the quantity of daily milk produced per Montbéliarde cow was estimated at 11.3 kg⁴². The difference with our findings could be attributed to the difference in the feed distributed to the animals. During the study conducted in Algeria, cows received improved feed ration while in our study area, just a few farmers used improved feed.

The overall biosecurity score recorded on the farms surveyed was low (mean score of 45.7%) with the majority of farms (61.8%) having poor level of biosecurity. This finding was unexpected, given that all farmers had received training on dairy farm biosecurity under the project. This is due to inadequate farm infrastructure (poor housing, insufficient feed storage facilities, and absence of a foot bath) and insufficient financial resources to ensure the biosecurity compliance. Our results are in agreement with Dhaka et al.²⁹ who reported a similar overall biosecurity score among 94 dairy farms in India. In Ethiopia, Harun et al.⁴⁴ reported that 55% of the 20 dairy farms surveyed had a poor biosecurity level. The discrepancy with our results (61.8% of farms with poor biosecurity) could be attributed to the difference in the herd size because all the farms involved in the study conducted in Ethiopia had more than ten cows whereas less than 25% of farms in our study had a comparable herd size. Several studies^30,48 have shown that the level of on-farm biosecurity implementation increases with the herd size. Poor implementation of biosecurity measures or hygiene has been correlated with low production performance^44–46 and increase prevalence of common bacterial infections⁴⁷ on dairy farms.

Biosecurity scores related to health (7.9%) and calving (11.9%) management were ranked lowest. This could be due to the higher economic investment needed to implement these measures. Furthermore, we observed an absence of calving pens and quarantine facilities or protocols on the majority of the farms visited. Similarly, Moje et al.⁴⁹ reported that among the 380 dairy farms included in their study in Ethiopia, 83% did not check the health status or quarantine newly introduced animals and 87% lacked isolation pens for sick and newly introduced cattle. Poor health management practices, such as the absence of quarantine facilities, can significantly contribute to the persistence of infectious diseases within farms resulting in reduced cow production. In addition, poor calving management practices can negatively affect the health, welfare, and productivity of dairy cows, and calves^50,51.

The recurrent diseases reported in Montbéliarde cattle were gastroenteritis, foot and mouth disease, infectious mastitis, trypanosomosis, and contagious bovine pleuropneumonia. All these diseases are among the priority diseases in Cameroon^52,53. The occurrence of these diseases on the farms surveyed may be attributed to the fact that newly imported Montbéliarde cows were not yet resilient in the new environment and were therefore more susceptible to pathogens. Poor health management practices on these farms may contribute to the increased spread of these diseases. The reported diseases are known to have serious impacts on milk production, animal health, and on the general condition of the animals, leading to high treatment costs and mortality and substantial economic loss for producers^54–56. The presence of zoonotic disease (trypanosomosis) among the diseases reported highlights a potential public health concern.

This study identified limited level of knowledge of farmers regarding AMR and AMU. This finding may be explained by the low level of education of the interviewees and their lack of training. In fact, the majority of farmers had not received any training in cattle husbandry. As shown by biosecurity assessment results, this further highlights the shortcomings of the project’s strategy. Farm owners who received training did not pass on the knowledge to the farm workers responsible for managing the farms. In a study conducted by Kallu et al.⁵⁷ in Ethiopia, half of farmers (57.7%) had good knowledge towards AMU and AMR. A higher proportion of ruminant farmers (60.8%) had good knowledge of AMU in Malaysia⁵⁸. The difference with our results could be attributed to the education levels of the farmers. In the Ethiopia study, 23.1% of the farmers had a higher level of education, whereas only 5.9% of the farmers in our study had this educational level.

Even though AMU is limited in dairy farms, the limited resources of farmers in our context, their lack of training in cattle management, and the presence of antibiotic residues in milk reported in previous studies^59,60, motivated the investigation of AMU practices. In farms surveyed, oxytetracycline was the most common used antibiotic for the treatment and control of animal diseases. This could be explained by the fact that oxytetracycline has a broader spectrum of activity. In addition, the cost of this drug may influence farmers’ choice and preference. These findings are consistent with previous reports by Vougat Ngom et al.⁵⁹ in the Far North region of Cameroon, Azabo et al.³⁵ in Dar es Salaam (Tanzania) and Kisoo et al.⁶¹ in Narok, Machakos and Makueni in Kenya where oxytetracycline was among the main antibiotics used by cattle farmers. This might also be attributed to the effectiveness, accessibility, and availability of veterinary medicines containing this AS.

Based on the UDD/DDD ratio of treatments, the majority of antibiotics used by farmers did not comply with the recommended dosages. The majority of antibiotics (90.2%) and all the critically important antibiotics for human medicine were overdosed. This is likely linked to the farmers’ limited knowledge of AMU. Such inappropriate dosing practices in cattle farms have been previously reported in the Far North of Cameroon⁵⁹ and in other African countries^35,62. The overdosing of critically important antibiotics increases the presence of antibiotic residues in milk and the emergence of AMR, representing a serious public health concern especially because farmers reported selling milk from cows under antibiotic treatment.

No correlation between biosecurity and the quantity of antibiotic used or milk production was noticed. The absence of correlation can be attributed to the difficulties encountered in collecting data on antibiotic use which relied on farmers’ recall due to poor record-keeping. This method of data collection can introduce bias, potentially affecting the accuracy of the results. Nonetheless, the quantity of antibiotics used in farms with a poor biosecurity remained slightly higher than in farms with good biosecurity. This highlights the importance of biosecurity in reducing AMU.

This study has some limitations. The main one is related to the fact that data on quantity of antimicrobial use relied primarily on farmers’ recall. This could be subject to potentially bias resulting in an over or underestimation of AMU. In addition, only few farms were assessed for cattle performance. Analysis of data from only 6 farms out of 48 does not support any inference. This implies that the collected data may not fully represent the real situation. Furthermore, additional indicators such as lactation period, peak production, dry period, and calving interval should be considered for a better investigation of the production performance of Montbéliarde cattle. While all these limitations do not invalidate the findings of this study, they should be kept in mind when interpreting the results of this study. A longitudinal assessment of milk production in all the regions of Cameroon where Montbéliarde cows have been distributed is needed to draw more robust conclusions. However, the findings of this study provide valuable insights for future research.

Three years after the distribution of the first batch of Montbéliarde, this study was conducted to assess the performance of Montbéliarde cows imported in Cameroon, as well as to evaluate biosecurity practices and AMU in the cattle farms. The results showed that only 75% of the farms that received Montbéliarde were still operating. Contrary to expectations, a low level of milk production and poor biosecurity were recorded on the farms. The majority of the farmers interviewed had insufficient knowledge of AMU and AMR. Antibiotics used in the farms were generally overdosed during treatment, with significant use of critically important antibiotics for human medicine. Poor biosecurity implementation can result in increased recurrence of animal diseases, reduced milk production and high antimicrobial usage leading to serious economic losses for farmers. That is probably why the majority of farms that received Montbéliarde breed started selling them less than a year after receiving these cattle. Therefore, intervention strategies such as sensitization and training of farmers and farm workers on biosecurity, dairy cattle management and appropriate AMU are vitally important to curb the observed results.

Methods

Study area and design

This cross-sectional and retrospective study was conducted between April and October 2024 in the Northern part of Cameroon which included Adamawa, North and Far North regions. With an estimated population of 1.5 million inhabitants in 2023, the Adamawa region (6th and 8th degrees of North latitude and 11th and 15th degrees of East longitude) has a tropical savannah climate. The dry season lasts from November to April with very little rainfall, and a rainy season occurs from May to October with abundant rainfall. Humidity is relatively high, with a maximum during the rainy season. Temperatures vary between 22 °C and 34 °C, dropping to 10 °C at certain times of the year²⁵. The North region (8th and 10th degrees of North latitude and 12th and 16th degrees of East longitude) has a sahelo-soudanian climate, with a long dry season from October to June and a short rainy season from July to September, with low and irregular rainfall and an average temperature of 35 °C. Humidity is relatively low, especially in the dry season. The population of this region was estimated at 2.6 million inhabitants in 2018²⁶. The Far North region (10th and 13th degrees of North latitude and 13th and 15th degrees of East longitude), with 18% of the country population in 2017 (4.2 millions), has a sahelo-soudanian climate with a short rainy season from July to October with low rainfall, very low humidity and an annual temperature ranging from 26 °C to 28 °C²⁷.

Sampling strategy

The Northern regions were selected for this study because the majority of the Montbéliarde heifers (80%) re-imported by the Cameroon government to improve milk production were distributed in these regions. In total, 493 Montbéliarde cattle were imported in Cameroon and 389 were distributed among farmers of the Adamawa (n = 306), North (n = 32), and Far North (n = 51) regions. Montbéliarde cattle were mainly distributed in these regions because these areas are known as the main cattle production zone in the country¹². The selection of the beneficiaries was based on the projects that they have submitted. They were also supposed to show that they were able to contribute to their projects by providing 10% of the total project cost requested. Each farmer received between 2 and 24 Montbéliarde heifers but 89% of farmers had received between 1 and 6 cattle.

Before data collection, ethical approval was obtained from the scientific research and ethics committee of the School of Veterinary Medicine and Sciences of the University of Ngaoundere (2024/061/UN/ESMV/DAACRS/SSFC). In addition, authorization to carry out the study was obtained at each regional office in charge of livestock of the study regions. These offices also provided us with the list and contacts of the target 64 people who had received Montbéliarde cattle within the framework of the above described project. The objective of the study was to survey all the 64 commercial farms. However, only farmers who gave their consent to participate were included in the study. They were not remunerated for their participation in the study. After obtaining verbal consent from cattle owners, data were collected by well-trained final-year veterinary students under the supervision of senior researchers.

Performance of Montbéliarde cattle

The production and reproduction performance indicators estimated were daily milk production, age at first calving, gestation length, body condition score (BCS), mortality and animal weight. In each farm, the BCS of all the Montbéliarde cows was assessed using the method developed by Bazin²⁸. This method is based on visual observation of certain body regions and anatomical points. The score ranged from 0 (excessively thin) to 5 (excessively fat). Animal weight was estimated as described by Edmonson²⁹.

To evaluate milk production, all farms with the records of daily milk production per cow from the previous year in the three regions were surveyed. In total, data from six farms, with their 72 cows, were used. This represents an estimated 18.5% of the Montbéliarde cows distributed in the study area during the project. The cows were milked twice daily in the morning and in afternoon. The following parameters were used to evaluate milk production.

Initial milk production

Initial milk production was considered as the average milk produced during the 4th, 5th, and 6th days of lactation. The first three days correspond to colostrum secretion, which is not considered as ordinary milk.

Daily milk production

Milk production from the morning and afternoon milking was summed together to calculate the daily milk production per animal.

Maximum milk production

It was determined as the maximum amount of milk produced daily per cow.

Biosecurity assessment in farms

Among the 64 that received Montbéliarde in the study area, biosecurity implementation was assessed in all farms whose owners or managers agreed to participate to this study. This was done during a face-to-face interview with farm owners or managers, followed by on-site technical observations by using the Biocheck.UGent™ questionnaire (Supplementary material 1) as previously described³⁰. This risk-based assessment tool allows quantification of the biosecurity status of dairy farms. In this questionnaire, questions about biosecurity are divided into external and internal biosecurity measures. External measures are related to purchase and reproduction, feed and water, transport and carcass removal, visitors and farm workers, and vermin control and other animals, while internal measures included health management, calving management, dairy management, calf management, adult cattle management, and working organization and equipment. Detailed information on Biocheck.UGent™ system for the dairy cattle is provided by Damiaans et al.³¹. After the survey in the farm, the answers obtained from the respondent were entered on the Biocheck.UGent™ platform (http://www.biocheck.ugent.be) in order to obtain the scores of each biosecurity subcategory. The survey results in a score ranged from 0 to 100 for both external and internal biosecurity subcategories. A score of 0 represents an ‘absolute lack of any biosecurity measures’, while a score of 100 indicates ‘full implementation of all assessed biosecurity measures’.

Farmers’ knowledge and practices about antimicrobial usage and resistance

Data on farmers’ knowledge and practices concerning AMU and antimicrobial resistance (AMR) were collected using a French structured questionnaire adapted from the studies of Moffo et al.³² and Hossain et al.³³. The questionnaire was pre-tested and then validated after interviewing five participants to minimize variations and improve its consistency. These respondents were not included in this study. Out of the 64 farms that received Montbéliarde, the survey was done in all farms where the owners agreed to participate. The persons in charge of drug administration were face-to-face interviewed during the visits in their farms. Indeed, in Cameroon in general, due to the lack of strict regulation concerning drug administration to animals, everyone can purchase and administer veterinary drugs. In a few cases, these questions were translated into Fulani to the participants who did not understand French. The translation was done by the investigators themselves. The questionnaire consisted of six sections: (i) farm localization; (ii) farmers’ socio-demographic characteristics (iii) farm characteristics, (iv) farmers’ knowledge regarding AMU and AMR, and (v) AMU practices. It isavailable from the corresponding author upon reasonable request.

Quantity of antibiotics used on farms

The quantity of antibiotics used during the six months preceding the survey was assessed in each farm using a data collection sheet developed in French. All the farms involved in biosecurity assessment have also participated to this part of the study. Detailed information concerning antimicrobial agents used was collected from the farm owners, managers, or the veterinarian of the farm. The collected data included the commercial name of the drug, the active substances, the number of animals treated, the treatment doses, the route of administration, the reason for AMU, the frequency of use and the number of days of treatment. Since all the farms relied on recall, photos of the packages and labels of antimicrobials used in cattle were used to minimize bias. Quantification of antibiotic used on each farm was based on dose metrics as described by Martin et al.³⁴. The quantity of active ingredient (milligrams) in each antimicrobial class were calculated as follows:

Active ingredients (mg) = no. of animals treated in the study period x antibiotic concentration (mg/ml) x units per treatment (ml) x treatments per day x number of treatment days.

The Used Daily Dose (UDDvet) was calculated following the below formula³⁵:

• Total mass of antibiotic (mg) = Number of animals treated × concentration (mg/ml) × dose administered per treatment (ml) × frequency of treatment per day × number of days of treatment.

• Biomass treated = Number of animals treated × standard weight.

The standard weight used for calculation was the one recommended by the European Agency for the Monitoring of Veterinary Antimicrobial Consumption (ESVAC), which is 425 kg³⁶. This weight was used because the standard weight of dairy cattle in Cameroon is the one of local cattle breeds. The Defined daily dose (DDDvet) was determined on the basis of the instructions on the drug’s leaflet³⁵. When a single dose was indicated on the label, this was taken as the DDDvet (mg/kg) and if a range of doses was reported, the mean was considered as the DDDvet (mg/kg)³⁷. For combined antimicrobials, the DDDvet value of each active ingredient was determined. In order to assess the appropriateness of dosage used during antibiotic treatment, the UDD to DDD ratio was used. Ratios between 0.8 and 1.2 were considered appropriate dosing, while value below 0.8 and above 1.2 were considered underdosing and overdosing, respectively³⁸.

Data management and statistical analysis

Data collected was first entered into Excel version 16.0., and then checked both quantitatively (number of completed questionnaires) and qualitatively (consistency of the data collected). After cleaning, data were imported into Statgraphic version 19 (Statgraphics Technologies Inc., VA, US) for analysis. Descriptive statistics were used to describe the socio-demographic profiles of the respondents and the characteristics of the farms. For cattle performance, the mean of the indicators were calculated and 95% confidence interval (CI) were reported when appropriate. For biosecurity assessment, a total score of less than 50 out of 100 was considered poor³⁹.

For AMU, antibiotics were categorized into four main groups based on their medical importance and the risk of AMR⁴⁰: highest priority critically important antimicrobials (HPCIA), critically important antimicrobials (CIA), highly important antimicrobials (HIA), and important antimicrobials (IA). Concerning farmers’ knowledge and practices about AMU and AMR, the responses collected were recorded using a binary scale with 1 representing a correct response and 0 representing an incorrect answer. The sum of the correct responses provided by each participant was divided by the total number of items in the category to obtain the score expressed in percentage³³. The mean was considered as a cut-off point to assess poor and better knowledge or practice. Scores were classified as “low” or insufficient scores < 50%, and “good” scores ≥ 50%. After performing a normality test, Wilcoxon and Kruskal-Wallis tests were used to compare two and more than two means, respectively. Pearson correlation test was used to investigate the correlation between two variables. The correlation existed when p < 0.05. Correlation between two variables was classified as weak (r < 0.30), moderate (0.30 ≤ r ≤ 0.50) or strong (r > 0.50). For all the analyses, the significance level was set at 5%.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

V.N.: Conceptualization, Data curation, Formal analysis, Visualization, Writing – original draft, Writing-review & editing, Supervision, Validation. M.A.: Data curation, Formal analysis, Investigation, Visualization, Writing-review & editing. N.E.: Conceptualization, Data curation, Formal analysis, Writing-review & editing. K.N.: Data curation, Formal analysis, Investigation, Visualization, Writing-review & editing. B.Y.: Data curation, Investigation, Visualization, Writing-review & editing. H.S.: Investigation, Visualization, Writing-review & editing. H.K.: Investigation, Visualization, Writing-review & editing. A.Z.: Conceptualization, Writing-review & editing, Supervision, Validation.

Data availability

The raw data supporting the conclusions of this article will be made available by the authors on request.

Declarations

Competing interests

The authors declare no competing interests.

Ethics approval and consent to participate

This study was conducted in accordance with relevant guidelines and regulations and approved by the scientific research and ethics committee of the School of Veterinary Medicine and Sciences of the University of Ngaoundere (2024/061/UN/ESMV/DAACRS/SSFC). Informed consent was obtained from all participants involved in the study.