关键词: 头孢洛宁乳房注入剂, 干乳期, 安全性, 产奶量, 体细胞数

Abstract:

【Objective】 The purpose of this paper was to investigate the safety of cefalonium intramammary infusion(dry cow) for target animals. 【Method】 Six primiparous and six multiparous healthy dairy cows were selected, which have not been treated with any antibiotics by systemic or intramammary administration 30 days before. Their daily milk yield was 15-35 kg. At day 1 and day 0 prior to administration of the tested drug, the daily milk production and body temperature of the tested animals were recorded, and their milk samples were collected for somatic cell count analysis. For milk sampling,the udder was rinsed with clean water and the nipples and the close skin were disinfected with 75% ethanol. Milk samples were collected in sterilized test tubes (milking by hand and discarding the first three times of milking). The collected sample were stored at low temperature (4℃) and sent to laboratory for testing within 6 h. For drug infusion, each quarter of udder was cleaned with a disinfected towel and the teats were soaked for 30 seconds with disinfectant. The drug was slowly inject into the quarter so that it could be evenly distributed. Each quarter was injected with a single dose of cefalonium (Dry Cow) (250 mg). Samples of each quarter were collected at 1, 3, 5, 7, and 10 days after the drug administration. Individual milk production, quantitative somatic cell count (SCC) and body temperature were recorded. Day 0 and day 10 milk samples were cultivated with selective medium to isolate bacteria. The isolated strains were identified according to their colony morphology, staining and biochemical characteristics. The main pathogens analyzed were Staphylococcus aureus, Streptococcus (Streptococcus agalactiae, Streptococcus uberis), Escherichia coli. 【Result】 During the whole test period, there was no clinical symptoms such as swelling, erythema, pain, or heat. On day 1, 0 prior to and 1, 3, 5, 7 and 10 day after administration of the drug, somatic cell count was 250-400 thousand per milliliter. The mean somatic cells count for the seven time points were 332.6, 327.4, 327.0, 316.3, 312.4, 306.2, 300.4 thousand per milliliter respectively, but there is no significant difference (P>0.05) among them by analysis of repeated measures anova. Daily milk yield was 23-33 kg. The average daily milk yield for the seven time points was 27.30, 27.35, 27.25, 27.40, 27.64, 27.83, 28.00 kg, respectively. It had no significant difference (P>0.05) by repeated measures anova. The rectal temperature of all tested cows before and after administration was within the normal range. The mean values of rectal temperature were 38.79, 38.82, 38.83, 38.77, 38.71, 38.71 and 38.69 ℃ respectively, and there was no significant difference (P>0.05). Therefore, according to the recommended dose of a single administration, it had no significant effect on somatic cell count, daily milk yield and rectal temperature of the tested animals. The results for bacteria isolation showed that there were 2, 3 and 4 strains of Streptococcus, Staphylococcus and Escherichia coli, respectively on day 0 of the administration of the drug, and there were 1, 1 and 0 strains of Streptococcus, Staphylococcus and Escherichia coli on day 10 after administration, respectively. The number of pathogens was significantly decreased through the treatment of the drug. 【Conclusion】 The recommended dose of cofalonium had no adverse effect on rectal temperature, milk yield and somatic cell counts for dairy cows after mammary administration. It is safe for the drug to be used in dairy cows by intramammary infusion (Dry Cow).

Key words: cofalonium intramammary infusion, dry cow, safety, milk yield, somatic cell counts