Avaliação dos impactos econômicos e influência climática na ocorrência de mastite em uma propriedade leiteira de Santa Maria - RS

Abstract

Among the diseases that affect the health of the dairy herd, mastitis is considered the most relevant, and the damage resulting from this disease is often unknown and/or underestimated by producers, especially by those who have less technical production, manual labor/family work, or that do not have the systematic monitoring of a sanitary veterinary. In the state of Rio Grande do Sul (RS), most of the places that sell milk to the industry are family farming establishments, so the objective of this work was to evaluate the economic impact of mastitis in the production of a small dairy property with family labor in the municipality of Santa MariaRS and to verify if the occurrence of mastitis is correlated with the climatic variations in the region. For this, between November 2021 and October 2022, mastitis diagnostic tests were carried out monthly. Moreover, evaluation of direct and indirect losses due to the disease, data on environmental temperature, relative humidity (UR), and local rainfall were obtained. For the diagnosis of mastitis, the strip cup test was used for clinical cases, and the California Mastitis Test for subclinical. Besides, milk was collected for microbiological culture from the affected mammary quarters, to determine the origin of the mastitis. Data referring to bulk milk somatic cell count (BMSCC) were obtained from the dairy industry that markets the milk. Climatic data were obtained from the website of the Center for Weather Forecasting and Climate Studies/National Institute for Space Research. The direct expenses comprise costs of medicines, veterinary care, disposal of milk, labor with treatment, and removal of animals. Indirect losses were estimated using the BMSCC. During the analyzed period, 25.06% to 33.43% of the herd's mammary quarters were affected by mastitis (median 29.83%), with clinical mastitis (median 3%) being above the median from November/2021 to February/2022 and October/2022; and the subclinical mastitis (median 27%) were more frequent in December/2021, March, April, May, June, August and July/2022, similar to the occurrence of environmental and contagious mastitis, respectively. Total losses represented 10.63% of gross profit from production, with direct losses totaling 37.43% of expenses, while indirect losses, such as the drop-in milk production, totaled 62.57% of economic losses. There were negative correlations between the occurrence of clinical mastitis and the monthly average of UR and in the occurrence of subclinical mastitis and the average monthly temperature. On the other hand, a positive correlation was observed between the occurrence of subclinical mastitis and the average UR. These results demonstrate that mastitis had a negative impact on the economy of the property in the study and there was a climatic influence on the occurrence of the disease. These findings could reflect the situation of other small dairy farms that have similar characteristics and that are located in the same region of the study.