Incontinentia Lactis: Physiology and Anatomy Conducive to Milk Leakage in Dairy Cows

Abstract

Incontinentia lactis is a possible predisposing factor for an elevated level of intramammary infection. The goal of the present study was to investigate possible causes of incontinentia lactis in dairy cows. Two farms that differed in breed composition, but that had similar average milk yields were studied: herd A, 28 kg/d, 31 Red Holstein cows; and herd B, 26 kg/d, 16 Brown Swiss cows. Herd A was classified into 2 groups: incontinentia lactis (ILA group) and control, whereas herd B was exclusively a control herd. Milk samples that represented foremilk and the main milk fraction were collected during 4 milking sessions. In addition, milk leakage samples from the ILA group were collected at different time intervals from 0 to 5 h before milking. Measurements of the teat, milk flow, fractions of cisternal and alveolar milk, intramammary pressure, and blood oxytocin pattern also were obtained. The ILA cows did not have differences in fat content between milk leakage and cisternal milk fraction. Milk fat content, however, increased during milking in response to continuous milk ejection (1.95, 1.99, and 4.61% for milk leakage, cisternal, and main milk samples, respectively). Teat canals were 9% shorter in the ILA cows, which showed greater milk yield, peak, and average flow rates. Quarter cisternal milk yield of ILA cows tended to be greater (0.50 vs. 0.23 and 0.28 kg for ILA and controls from herds A and B, respectively), whereas percentages of cistern milk and alveolar milk did not differ from controls. The greater pressure in the ILA group, both before and after manual udder stimulation (ILA: 4.0 and 6.4 kPa; control: 2.0 and 5.0 kPa, respectively), could be an important cause for the leakage. Nevertheless, the increase in IMP that occurred after udder preparation affirms that milk ejection occurred in response to the tactile teat stimulation, but not before the onset of leakage. Blood oxytocin concentration in ILA cows was low until the start of udder preparation and increased in response to the milking stimulus (reaffirming the hypothesis that milk leakage occurred in the absence of milk ejection). In conclusion, milk losses by leakage are likely due to the large amount of cisternal milk, which creates pressure and causes leakage, in the absence of milk ejection.

Measurement of fecal glucocorticoid metabolites and evaluation of udder characteristics to estimate stress after sudden dry-off in dairy cows with different milk yields

“…Furthermore, our study indicated that a high extramammary udder pressure increased the risk of milk leakage. For lactating cows, a similar relationship between intramammary udder pressure and milk leakage has been demonstrated (Rovai et al, 2007). In contrast to Rovai et al (2007), our data, however, also revealed a relationship between milk leakage after dry-off, parity, and udder pressure.…”

“…For lactating cows, a similar relationship between intramammary udder pressure and milk leakage has been demonstrated (Rovai et al, 2007). In contrast to Rovai et al (2007), our data, however, also revealed a relationship between milk leakage after dry-off, parity, and udder pressure. A relationship between the decreasing integrity of the teat canal in higher-parity cows and enhanced risks for IMI was already demonstrated in a previous study (Ding-well et al, 2004).…”

“…We speculate that these conditions of the teat canal in older cows provoke milk leakage, too. It remains unclear why this effect was not observed in peak-lactation cows (Rovai et al, 2007). We presume that the udder pressure plays an important role; nonetheless, further studies are warranted to elucidate this association.…”

Objective measuring technique for teat dimensions of dairy cows

“…More objective methods have been used to determine teat length and teat diameter, such as measuring tapes, callipers and transparent open-ended tubes with graduated scales (Bakken, 1981;McKusick, Berger, Thomas, 1999;Rovai, Kollmann, Bruckmaier, 2007;Tilki, Inal, Colak, Garip, 2005). Teat diameters can also be measured using a cutimeter, by removing the calliper spring or by holding the jaws open manually to neutralise the spring pressure (Hamann, Mein, Nipp, 1996).…”

Algometer Precision for Quantifying Mechanical Nociceptive Threshold When Applied to the Udder of Lactating Dairy Cows

“…Practices such as abrupt cessation of milking at drying-off ( 1 ), prolonged milking intervals ( 2 ), and incomplete milking at the beginning of the lactation ( 3 , 4 ), may lead to udder distension, milk leakage, and inflammatory responses ( 5 , 6 ). Under such conditions, the animals may experience increased mechanical sensitivity, perhaps to a level where their welfare is negatively affected ( 7 ).…”