Association between udder morphology and in vitro activity of milk leukocytes in high yielding crossbred cows

Abstract

Aim:The present investigation was conducted to study the association between udder morphology and in vitro activity of milk leukocytes in high yielding crossbred cows.Materials and Methods:A total of 48 healthy high yielding crossbred cows were selected for the study. The udder configuration and teat/udder morphology were recorded before milking. Milk samples (100 ml/cow) were collected aseptically. Milk somatic cell counts (SCC) and milk differential leukocyte counts were performed microscopically. Milk leukocytes (viz., neutrophils, lymphocytes, and macrophages) were isolated from milk samples by density gradient centrifugation. Phagocytic index (PI) of milk neutrophils and macrophages were evaluated by colorimetric nitro blue tetrazolium assay. Lymphocytes proliferation response was estimated by MTT assay and expressed as stimulation index.Results:There was a significant (p<0.01) positive correlation between milk SCC with mid teat diameter, teat base diameter and significant (p<0.05) negative correlation between milk SCC and the height of the teat from the ground. Milk SCC was found to be significantly (p<0.01) lower in bowl-shaped udder and higher (p<0.01) in pendulous type. Milk macrophage percentage was positively (p<0.01) correlated with udder circumference. PI of milk neutrophil was negatively (p<0.01) correlation between teat base diameter, and PI of milk macrophages was found to be positively (p<0.01) correlated with teat apex diameter. Both PI of milk neutrophils and macrophages was found to be significantly (p<0.01) lower in the animals having flat and round teat and pendulous type of udder. In vitro PI of milk neutrophils was found to be significantly (p<0.01) lower in flat teat. In vitro PI of milk macrophages was found to be significantly (p<0.01) lower in the round and flat teats compared to pointed and cylindrical teats.Conclusion:Udder risk factors such as teat shape and size, teat to floor distance, udder shape, and size may decrease the in vitro activity of milk leukocytes hence facilitates the incidence intramammary infections.

Associations of teat morphometric parameters and subclinical mastitis in riverine buffaloes

“…However, a negative correlation between SCC and teat-end to floor distance was found in this study ( P < 0·05). Similar findings were also reported by Sharma et al (2017) in dairy cows.…”

“…Hussain et al (2013) found a significant ( P < 0·001) association between teat shape (classified as pointed, cylindrical, round and flat) and occurrence of mastitis in Nili-Ravi buffaloes; teats with round and cylindrical shapes being more susceptible to mastitis than pointed teats. On the contrary, Sharma et al (2017) did not observe any association between milk SCC and different teat shapes in high yielding crossbred cows. With respect to teat-end shapes, it has been reported that as the teat-end shape changes from pointed toward flat and inverted, SCC increases (Seykora & McDaniel, 1985).…”

“…On the contrary, Bharti et al (2015) observed a positive correlation of SCC with TL and TD. Coban et al (2009) and Sharma et al (2017) also observed a positive correlation between mastitis and TD. However, a negative correlation between SCC and teat-end to floor distance was found in this study ( P < 0·05).…”

Milk somatic cells, factors influencing their release, future prospects, and practical utility in dairy animals: An overview

“…High milk-producing cows are under stress of milk production, and their immunity becomes low leading to more SCC in their milk [ 29 ]. High milk SCC not only negatively affects milk yield but also milk composition and quality [ 30 ], and younger cows due to their low milk-producing ability have lower SCC [ 31 ].…”

In vivo measures of mammary development in gestating gilts1

“…Effects of lactation number and lactation month on various udder morphological traits (including front teat diameter) were observed in Holstein cows (Ceyhan et al, 2015). Furthermore, Sharma et al (2017) noted that udder morphological traits (including teat shape and size) could have an impact on milk leukocyte counts, and, hence, udder health, in crossbred cows. Nevertheless, no relation was reported between teat characteristics and mammary development per se.…”