Department of Veterinary Medicine and Animal Husbandry, Somali National University, Mogadishu, SomaliaSomalia
University of Somalia, Jidka Warshaddaha, Mogadishu, SomaliaSomalia
Food and Agricultural Organization, Mogadishu, SomaliaSomalia
Also available as PDF (figures and tables appear in the PDF).
Introduction Mastitis is one of the major diseases that affect dairy goat production. It occurs after several microbes invade and colonize the secretory tissue, leading to inflammation of the mammary glands. While mastitis can be caused by many infectious or non-infectious agents, it is classified as clinical and subclinical. Mastitis is one of the major problems and the top complaint from stakeholders of dairy goats in the Banadir region. Objectives The objectives of the study were to determine the prevalence of mastitis in goats and to find out the significant risk factors associated with mastitis in goats. Methodology A cross-sectional study was carried out between January and July 2022. The study population was all the lactating goats and does in the Banadir region. A total of 207 lactating goats were randomly selected from goat farms in some selected districts of the Banadir region and screened for subclinical mastitis using the California Mastitis Test (CMT). Results Based on CMT results, an overall subclinical mastitis prevalence of 67.6% was found. According to the risk factors, the study revealed that the lactation period (p=0.002) and body condition (p=0.005) had a significant association with the prevalence of mastitis, whereas the late lactation stage and poor body condition had the highest prevalence (73% and 79%, respectively). However, there was no statistically significant association between mastitis infection and risk factors such as study udder injury (p=0.191), age (p=0.284), hygiene (p=0.319), and parity number (p=0.620). Conclusion The current research has shown that mastitis is extensively common among lactating goats in the area under study, with numerous risk factors identified that make the udder susceptible to infections. Recommendation The study recommends farmers be vigilant and closely monitor their dairy goats for mastitis during the late stage of lactation and in advanced age, immediate treatment of injured udders, and regular screening.
Keywords: Banadir; Goats; Mastitis; Prevalence; Risk factor; Subclinical
Mastitis is one of the major diseases that affect dairy goat production. It occurs after several microbes invade and colonize the secretory tissue, leading to inflammation of the mammary glands. While mastitis can be caused by many infectious or non-infectious agents, it is classified as clinical and subclinical. Mastitis is one of the major problems and the top complaint from stakeholders of dairy goats in the Banadir region.
The objectives of the study were to determine the prevalence of mastitis in goats and to find out the significant risk factors associated with mastitis in goats.
A cross-sectional study was carried out between January and July 2022. The study population was all the lactating goats and does in the Banadir region. A total of 207 lactating goats were randomly selected from goat farms in some selected districts of the Banadir region and screened for subclinical mastitis using the California Mastitis Test (CMT).
Based on CMT results, an overall subclinical mastitis prevalence of 67.6% was found. According to the risk factors, the study revealed that the lactation period (p=0.002) and body condition (p=0.005) had a significant association with the prevalence of mastitis, whereas the late lactation stage and poor body condition had the highest prevalence (73% and 79%, respectively). However, there was no statistically significant association between mastitis infection and risk factors such as study udder injury (p=0.191), age (p=0.284), hygiene (p=0.319), and parity number (p=0.620).
The current research has shown that mastitis is extensively common among lactating goats in the area under study, with numerous risk factors identified that make the udder susceptible to infections.
The study recommends farmers be vigilant and closely monitor their dairy goats for mastitis during the late stage of lactation and in advanced age, immediate treatment of injured udders, and regular screening.
Banadir; Goats; Mastitis; Prevalence; Risk factor; Subclinical.
2024 by Salah OM. This is an open-access article distributed under Creative Commons Attribution 4.0 International License (CC-BY 4.0 DEED)
M astitis, an inflammation of the mammary gland, is defined by changes in milk’s physical, chemical, and bacteriological properties, along with pathological alterations in glandular tissues,
irrespective of the cause.1 Early detection and prompt action are key to reducing tissue damage and production loss in combating mastitis, with a focus on prevention and control of both clinical and subclini-
24 Original Research | Volume 9 | Issue 1 | cal forms due to treatment’s limited success.2 Milk from goats suffering from mastitis presents a significant risk to veterinary health and poses epidemiological concerns. In addition to causing hygiene and health issues, the mammary gland inflammatory processes also cause economic losses due to reduced milk productivity, early culling of animals, and treatment costs.3 Mastitis commonly occurs due to inadequate hygiene practices and can be triggered by injuries to the mammary tissue or teats resulting from trauma, nursing, fly bites, or other skin wounds that serve as crucial barriers against infection. Additionally, mastitis can be associated with the presence of viral, bacterial, or fungal pathogens and their toxins. When exposed to stressful conditions like extreme temperatures, muddy or wet living environments, or sudden dietary changes, a does immune system may become compromised, making it challenging to fend off the invasion of foreign agents that contribute to diseases such as mastitis.4-6 Another predisposing factor is the abnormal anatomy of the udder, or teat. Infection takes place when pathogens make their way to the mammary gland. These infectious agents enter via the milk duct, engage with the cells of the mammary tissue, and then proliferate. Some microorganisms release toxins. The mammary gland becomes inflamed in response to these toxins and can contract infection after birth, but infection can also occur during lactation and after dry periods.7 Although it is not possible to completely eradicate mastitis in a goat flock, its occurrence can be minimized. Essential factors for control include practicing good husbandry and maintaining proper sanitation. It is important to ensure that the barn, milking area, and exercise space have effective drainage and ventilation systems, creating a clean and comfortable environment for the goats. The pasture area should be kept free of excessive debris and barbed wire. Additionally, all goats should undergo dehorning and receive regular foot care, reducing the risk of traumatic injuries to the teats and udder.7 Goats displaying open, draining abscesses should be isolated or, ideally, removed from the herd. It is crucial to follow proper milking procedures and maintain hygiene standards. Clipping the hair on the udders and flanks is necessary to prevent the accumulation of dirt and excessive moisture. Teat and udder preparation involves washing the teats and the base of the udder with a warm water disinfectant solution, utilizing a disposable paper towel for each goat. This process aims to remove visible dirt and debris and stimulate milk letdown. Afterward, another disposable paper towel should be used to thoroughly dry the teats and udder. Before commencing milking, it is important to examine a foremilk sample on a strip plate or strip cup. Milkers should take care to maintain clean and dry hands, preferably using rubber gloves.1 Goats are significant for the subsistence of a large population in the developing world, especially the weaker and downtrodden sections, who are the most vulnerable members of society in terms of undernourishment and poverty. The dairy goat industry has rapidly gained importance throughout the world in recent years.3 Goats are important for the livelihood of many people in the Third World, especially women, children, and the elderly, who are the most vulnerable members of society in terms of undernourishment and poverty. In semiarid areas where animal feed availability is scarce and poor, goats are efficient utilizers of fibrous feed, and because of their small body size and low feed intake, they are more useful and economical to the owners.8,9 The animal population in Somalia was estimated to be 52 million herds, of which 30.5 million are goats, with 80-91% females and 9-20% males, averaging 0.6 liters of milk per goat daily.10 The predominant goat breeds in the area include the long-eared Somali goat, the short-eared Somali goat, and, to a lesser degree, the Somali Arab goa.11 Despite the large number of animals in Somalia, there is a shortage of milk availability, which led to extensive consumption of imported powder milk, which subsequently led to discouragement in the development of the dairy sector in Somalia. The shortage of milk and milk production could have many causes, but a prime cause is believed to be mastitis. However, information on mastitis in Somalia, particularly in the Benadir region, is lacking or inadequate. 12 Although many studies related to the problem under investigation have been conducted in many parts of the world, there is a literature gap in the study area, as there is not a single study carried out exclusively on mastitis in dairy goats in the Banadir region. Therefore, this study is intended to bridge this knowledge gap and find out the prevalence and risk factors of mastitis in goats.
The overall objective of this study is to determine the prevalence and risk factors of mastitis in goats in the Banadir region of Somalia.
A cross-sectional study was conducted from January to July 2022 to determine the prevalence of mastitis in the study area. The California Mastitis Test (CMT) was used to examine all lactating animals.
The study animals were lactating dairy goats of different ages and stages of lactation in the Banadir region. The breeds were local breeds.
The Benadir region consists of 18 districts. It borders the middle Shebelle in the north and east, the lower Shebelle in the west, and the Indian Ocean in the south.
The study was carried out in seven districts of the Bena- 25Original Research | Volume 9 | Issue 1 | dir region, namely, Dharkenley, Wadajir, Dayniile, Kaaran, Yaqshiid, Heliwa, and Wartanabada districts. The region lies between latitude 2°2’59”N and longitude 45°15’44”E.13 Although by far the smallest administrative region in Somalia, it has the largest population, estimated to be about 1,650,227 (including 369,288 internally displaced persons), and covers an area of approximately 96,878 km2.13,14 These are high-potential areas that are densely populated, and the goat population is also high. The sites were purposively selected based on the large population of goats. Samples were collected randomly from the goat household’s farms.
The sample size was determined using the formula by Arya et al 15. Sample size=n=(Zα 2pq)/L2 , where n is the required sample size, Zα=1.96 is the normal deviation at the 5% level of significance, q is the estimated prevalence (in percentages), and L is the precision of the estimate, which is considered to be 5%=0.0516.
Since the prevalence of mastitis in goats in some districts of the Benadir region is estimated at 16%.12 Zα 2pq Sample size n= L2 (3.8416×0.16×0.84) 0.51631104 n= = = 206.524 = 207 0.0025 0.0025 The total sample size was 207 lactating dairy animals.
All milk samples were collected from each teat of the goat’s udder during the ongoing milking process and analyzed by the CMT, which was done at the goat side. Before sampling, the udder of the goat was thoroughly washed with water and dried with a clean towel. The first 3-4 streams of milk were discarded, and then 5-10 mL of milk was collected from each teat aseptically and put in a separate CMT paddle held at a slightly horizontal position in order to avoid contamination from the udder.16 Milk samples from each half of the udder are collected on a clean CMT paddle. The CMT paddle features four shallow cups labeled A, B, C, and D, designed to distinguish the specific quarter of the udder from which the milk sample was taken. Each of the four shallow cups has marking lines measuring 2 mL. Interviews were conducted to collect additional data.
The test was conducted according to Mellenberger et al. 17 California mastitis reagent was used to screen dairy animals. From each halve of the udder, each of the milk samples measuring 2 mL was placed in two of the cups on the California mastitis test (CMT) paddle, and using a syringe, an equal amount of CMT reagent was added to each cup and mixed well. The test result was scored from 1-5 according to the Scandinavian scoring system, where 1 is a negative result (no gel formation), 2 is traceable (possible infection), and 3 or above indicates a positive result, where 5 has the most gel formation.18 According to the Scandinavian scoring system, the test was scored according to the agglutination and viscosity level of mixtures (reagent and milk). The interpretation was in such a way that the CMT score was 1 negative (no gel formation), score 2 was traceable gel formation (possible infection), and score 3 was visible gel formation. 4 and 5 had the most gel formation. Apart from 1 where there was no gel formation, the rest, 2 to 5, were considered positive.
All data collected were entered into a Microsoft Excel 2019 spreadsheet as a database and into Statistical Package for the Social Sci ences ( SPSS) for statistical analysis. Descriptive statistics were generated using the same statistical package. Differences in pro portions were assessed using the frequency tables in the SPSS program.16 The significance of risk factors on the presence of mastitis (the variable outcome) was calculated using the chi-square (χ2) technique to test the existence of a statistical association between mastitis and the risk factors (explanatory variables) such as site, age, stage of lactation, body condition score, udder injury parity number, and hygiene. In all chi-square test applications, the level of p<0.05 was considered statistically significant.12
The study found that the overall prevalence of goat mastitis in the Banadir region is 67.6 (Table 1).
When infection in quarters was compared, out of the 140 positive animals, 104 (74%) samples were infected with both halves, while 16% of the animals were infected with the right halves and 10% with the left halves. This result shows the right half has more infection than the left. (Table 2).
Table 3 explores mastitis prevalence in relation to risk factors such as udder injury, age, animal hygiene, body condition score, and parity number.
Negative 67 32.4 T otal 207 100.0
The analysis revealed a higher mastitis prevalence in animals with udder injuries (73%) versus those without (65%), yet the difference wasn’t statistically significant (chi-square=1.092, pvalue=0.191). The study found mastitis prevalence increased with age—64%, 70%, and 82% for age groups 1-3, 4-6, and ≥7 years, respectively. However, this trend was not statistically significant (chi-square (χ2)=2.515, p-value=0.284). According to animal hy giene, the study found that 73% of the animals with poor hygiene conditions were infected with mastitis, 65% of those with fair hygiene, and 61% of those with good hygiene were also found to be positive for mastitis, although the difference wasn’t statistically significant (χ2=2.28, p-value=0.319).
Animals with poor body conditions exhibited the highest prevalence (79%), compared to those with medium (67%) and good body conditions (65%). Notably, this factor showed a statistically significant difference in mastitis prevalence across groups (chi-square value of 10.797; p-value of 0.005). The study found a higher prevalence of mastitis in goats with 4-5 parity numbers (73%; 40/55) and >6 parity numbers (68%; 15/22) compared to 1-3 parity numbers (65%; 85/130). Although there is no significant difference (chi-square=0.955, p-value=0.620).
The results of the study showed that the overall prevalence of subclinical mastitis in some selected districts of the Banadir region on CMT results was 67.6%. The findings in this study were in close agreement with results reported in Kenya 61%,16 Bangladesh 50.9%,19 and Pakistan 61.8%.20 The results recorded in this study were higher than those recorded in other studies: Ethiopia 25%,21 India 19.89%,22 Pakistan 38%.23 However, the results of the study were lower than those recorded in Bangladesh, with 71.6% by Begum et al. 24 The prevalence of subclinical mastitis differs among countries. This might be due to the differences in host and management risk factors that influence intra-mammary infection in goats.16 There was a positive association between the prevalence of mastitis and the presence of lesions on the tongue or udder. This finding was not unexpected since injuries to the teats and T able 3. Prevalence of Mastitis in Relation to Risk Factors Variables Category Negative Negative % Positive Positive % χ2 p-value Udder injury Yes 15 27% 41 73% 1.092 0.191 No 52 35% 99 65% T otal 67 140 Hygiene level Poor 22 27 61 73 2.28 0.319Fair 33 35 60 65 Good 12 39 19 61 T otal 67 140 Lactation Stage Early 22 56 17 44 0.002Mid 30 27 83 73 Late 15 27 40 73 T otal 67 140 Body condition Poor 19 21 71 79 0.005Medium 13 33 26 67 Good 35 45 43 65 T otal 67 140 Parity number 1-3 45 35 85 65 0.955 0.6204-5 15 27 40 73 >6 7 32 15 68 T otal 67 140 T able 2. Prevalence of Mastitis According to Quarter Infected Variable Category Frequency Percentage Infected halve.
T otal 140 100.0 27Original Research | Volume 9 | Issue 1 | udders could provide a portal of entry for microorganisms, thus causing infection.25 This finding agreed with a study in Colombia,26 which reported no association between the occurrence of mastitis and the presence of lesions on the teats or udder of dairy goats. According to the current study, animals aged 7 years or older recorded a higher infection rate (82%) than those in age groups 1-3 years (64%) and 4-6 years (70%). Although the differ ence was not statistically significant ( p=0.284), some other studies support the findings in this study. A study carried out in Indonesia reported no significant association between age and subclinical mastitis.27 Another study in the United States reported a significant association between older age and the high prevalence of masti tis.26 The reasoning behind this could be that older animals are subjected to stress resulting from the production of milk for a long time and the multiple births, which make such animals easily sus ceptible to infectious agents due to their low immunity.28 According to the distribution of the infection on the udder, the study revealed that the majority of the positive animals (74%) were infected with both halves, and 26% of the animals were infected with only one half (left half or right half). Similar findings were declared in Kenya.29 The study has also shown that the right half had a higher prevalence (16%) than the left half (10%), which is contrary to the findings of studies carried out in Spain.28 The results of this study revealed that there was an association between poor hygiene and an increased rate of infection. These results agreed with the previous finding, 30 which reported that there was a high association between poor hygiene and the prevalence of mastitis. This is underscored by the observation that the majority of pathogens responsible for subclinical mastitis in goats are present in the animals’ surroundings and on their skin. So, farmers who did not clean and change their pen bedding frequently created an environment where pathogens could harbor and hence infect the goat’s udder and halves.16 A statistically significant association (p=0.002) was found between the lactation stage and the prevalence of mastitis. Animals in the late stage of lactation were found to have the highest prevalence (73%), while those in the early stage of lactation had the least prevalence (17%). These findings agree with the result by researchers,19,25,31 who concluded that the later stage of lactation had more infection than the earlier lactation stage; the reason could be the accumulation of infectious agents in the previous lactations.32 A significant association ( p=0.005) was also found between body condition score and the rate of infection with mastitis, where animals with poor body condition had the highest prevalence of mastitis (79%). This could be associated with the reduced defense status of the animals, which increases susceptibility to udder infections by opportunistic organisms. The association of poor body conditions with increased mastitis prevalence has already been demonstrated in dairy cattle.33 There was no significant association (p=0.620) between increased parity and the occurrence of mastitis in goats. Similar results were declared by a researcher in Ethiopia who found no association between the occurrence of mastitis and parity.19 A similar infection pattern was reported elsewhere.33 Contrarily, another finding reported that goats in their third and fourth parties were more prone to mastitis infection than goats in their first or second parties.30 The increasing prevalence of the parity number may be due to the decreased immunity of the animal to exposure to pathogens.
The current research indicates that mastitis is a common condition among lactating goats in the study region, with various risk factors identified that make the udder susceptible to infections. The important risk factors found in the study include age, parity, udder injury, hygiene, body condition score, halves infected, and lactation. and is a major health problem for dairy animals and will have an adverse effect on the productivity of dairy goats, hence needing serious attention. There was a strong association between mastitis and risk factors, as stipulated by lactation stage and body condition. The association between mastitis and some risk factors was not very strong. All of these are indications that mastitis is posing a major challenge to goat production in the study, which necessitates the effort to control and mitigate its effects. There, the following recommendations are forwarded: 1. Farmers should be trained on the control of mastitis and the use of good milking hygiene, post-milking teat dipping, dry-off therapy, and culling of chronically infected goats.
2. Among the risk factors, poor body condition can be improved through supplementary feeding of lactating animals and treatment against parasitic infections.
3. Farmers should be informed to be vigilant and closely monitor their dairy goats for mastitis during the late stage of lactation and in advanced age, since this is the time when mastitis usually occurs. 4. The goat farmers should be encouraged to obtain CMT test kits, and some members of the group should be trained on how to use them.
5. Instead of attempting self-treatment, farmers ought to seek guidance from a qualified professional when dealing with mastitis in goats.
6. Immediate treatment of udder injuries and wounds is essential to prevent the onset of mastitis.
7. Further investigations into pathogens involved in goat mastitis should be carried out, which will optimize our knowledge of causative agents and control interventions.
I express my gratitude to the administration of the Faculty of Veterinary Medicine and Animal Husbandry at Somali National University for granting me access to their facility. Additionally, I would like to acknowledge and thank the farmers who generously allowed me to access their farms and enroll their animals in the research. Their kindness and hospitality throughout the entire duration of the study were greatly appreciated. Furthermore, I extend my appreciation to the authors and publishers of the 28 Original Research | Volume 9 | Issue 1 | various books, papers, journals, and publications that I referenced and drew inspiration from during my research. I duly acknowledged and cited their ideas in my paper.
Datasets used and analyzed during the current study are available from the corresponding author on request.
The current study was conducted without the help of any funding source.
The approval of ethical committee was taken for conducting this study and followed all the animal ethics and welfare guidelines.
The authors declare that they have no conflicts of interest.