Effect of Once Daily Milking and Concurrent Somatotropin on Mammary Tight Junction Permeability and Yield of Cows

Stelwagen, K.; Davis, Stephen R.; Farr, V. C.; Eichler, Stephen J.; Politis, I.

doi:10.3168/jds.s0022-0302(94)77240-4

Cited by 79 publications

(86 citation statements)

References 10 publications

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“…This was consistent with the findings of Salama et al (2003) in goats, Castillo et al (2008) in ewes and Lacy-Hulbert et al (1999) and Stelwagen et al (1994) in cows. Other studies have reported an increase in the SCC in cows subjected to ODM (Stelwagen and Lacy-Hulbert, 1996;Kelly et al, 1998).…”

Section: Discussionsupporting

confidence: 92%

Use of milk epithelial cells to study regulation of cell activity and apoptosis during once-daily milking in goats

Chedly

Lacasse

Marnet

et al. 2011

Animal

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Generally, once-daily milking (ODM) decreases milk yield. This effect may be the consequence of a decrease in mammary epithelial cell (MEC) activity or a reduction in their number. The aim of this study was to determine the effect of ODM on the synthetic activity and rate of apoptosis of MEC using a non-invasive method. Eight Alpine goats were subjected to ODM or twice-daily milking for two 5-week periods. MECs were purified by centrifugation and immunocytochemical binding in milk after 1 and 5 weeks of each period. mRNA levels of some proteins involved in lactose and milk protein synthesis and in apoptosis were evaluated using real-time PCR. Isolation of MEC from milk was a useful method to investigate transcriptional regulation in a timeline study. ODM induced greater decreases in milk, lactose and protein yields after 1 week than after 5 weeks. This suggests an adaptation of the mammary gland to ODM, which reduces the inhibitory effect of this practice. Reductions in milk component yields were associated with lower a-lactalbumin transcripts, suggesting a transcriptional decrease of lactose synthesis during ODM. Glucose transporter GLUT1 transcripts were downregulated under ODM, suggesting that lactose precursor uptake by MEC might be involved in the regulation of lactose synthesis. k-Casein mRNA levels tended to be lower during ODM. ODM increased levels of the pro-apoptotic transcript Bax after both 1 and 5 weeks, but no variation was observed in the Bax/Bcl-2 ratio. ODM affected cell synthetic activity through transcriptional regulation and may have induced apoptosis. The reduction of the negative effect of ODM on milk yield suggests that Alpine goats are able to adapt to ODM. Further studies are needed to investigate the effect of ODM on MEC turnover.

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Section: Discussionsupporting

confidence: 92%

Use of milk epithelial cells to study regulation of cell activity and apoptosis during once-daily milking in goats

Chedly

Lacasse

Marnet

et al. 2011

Animal

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“…Following its elevation in plasma lower lactose concentration is expected in milk. Although plasma lactose baseline levels were restored rapidly, milk stability and yield remained depressed (results not presented), paralleling the results reported by Stelwagen et al (1994) for plasma lactose and milk yield. Another parameter used to access the permeability of mammary gland cell TJs is the elevation in the concentration of milk sodium.…”

Section: Resultssupporting

confidence: 85%

“…These authors measured plasma lactose and other attributes only at the end of the trial, 25 days after the beginning of the restriction, and therefore the dynamic and transient response of TJ (Stelwagen et al, 1994) might be responsible for the absence of difference in TJ permeability in that experiment.…”

Section: Resultsmentioning

confidence: 99%

“…TJs are impermeable when in perfect condition, not allowing the influx of components from blood into milk, and vice-versa (Stelwagen et al, 1998a). In spite of this, several factors, such as stress (Stelwagen et al, 2000), mammary involution at the end of lactation (Fleet and Peaker, 1978), longer milking intervals (Stelwagen et al, 1994) and mastitis (Leitner et al, 2004) can alter TJ impermeability. By changing this impermeability, the main characteristics of TJ are lost, altering milk basic composition, especially saline balance, which can eventually lead to modifications in milk stability.…”

Section: Introductionmentioning

confidence: 99%

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Severe feed restriction increases permeability of mammary gland cell tight junctions and reduces ethanol stability of milk

Stumpf

Fischer

McManus

et al. 2013

Animal

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A total of twelve lactating Jersey cows were used in a 5-week experiment to determine the effects of severe feed restriction on the permeability of mammary gland cell tight junctions (TJs) and its effects on milk stability to the alcohol test. During the first 2 weeks, cows were managed and fed together and received the same diet according to their nutritional requirements (full diet: 15 kg of sugar cane silage; 5.8 kg of alfalfa hay; 0.16 kg of mineral salt and 6.2 kg of concentrate). In the 3rd week, animals were distributed into two groups of six cows each. One group received the full diet and the other a restricted diet (50% of the full diet). In the 4th and 5th weeks, all animals received the full diet again. Milk composition and other attributes, such as titratable acidity, ethanol stability, pH, density and somatic cell count (SCC) were evaluated. Cortisol levels indicated the stress condition of the cows. Plasma lactose and milk sodium were measured to assess mammary TJ leakiness. Principal factor analysis (PFA) showed that the first two principal factors (PFs) contributed with 44.47% and 20.57% of the total variance in the experiment and, as feeding levels increased, milk stability to the ethanol test became higher and plasma lactose levels decreased, which indicates lower permeability of the mammary gland cell TJ. Correspondence analyses were consistent with PFA and also showed that lower feeding levels were related to reduced milk stability, high plasma lactose, high sodium in milk, low milk lactose (another parameter used to assess TJ permeability) and higher cortisol levels, indicating the stress to which animals were submitted. All observations were grouped in three clusters, with some of the above-mentioned patterns. Feeding restriction was associated with higher permeability of TJ, decreasing milk stability to the ethanol test.

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“…Numerous former investigators (Allen, 1990;Stelwagen et al, 1994Stelwagen et al, , 1997Nguyen and Neville, 1998;Sloth et al, 2003;Bruckmaier and Meyer, 2005) assumed that changes in TJ protein structure might be existent when SCC and EC levels in milk increased, lactose occurred in blood and a reduced milk yield can be observed. Consequently the influence of 100 µg im infused LPS on TJ proteins OCLN, ZO-1, ZO-2 and ZO-3 in mammary tissue samples was evaluated in order to find confirmations for these suggestions.…”

Section: Experiments IImentioning

confidence: 99%

Dose-dependent immune response in milk cells and mammary tissue after intramammary administration of lipopolysaccharide in dairy cows

Werner-Misof¹,

Pfaffl²,

Bruckmaier³

2007

Vet. Med. - Czech

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The immune response in milk cells and the status of mammary tight junctions (TJ) in response to intramammary (IM) infusion of different doses of Escherichia coli lipopolysaccharide (LPS) was investigated. Experiment I: Seven German Braunvieh cows were IM infused into one quarter with 1 μg (LPS-1) and 3 μg (LPS-3) of LPS, respectively, and the contralateral control quarter with saline (9 g/l; C). Milk samples were taken immediately before and 12, 24, 36, 48, 60, 84 and 108 h after infusion and analysed for somatic cell counts (SCC), lactose, sodium (Na) and chloride (Cl) ions, and electrical conductivity (EC). Milk cell mRNA expression of various inflammatory factors was quantified by real-time RT-PCR. Blood samples were taken immediately after milking for the analysis of leukocytes (WBC), polymorphonuclear neutrophils (PMN), Na and Cl. Milk SCC, lactose, Na, Cl and EC did not differ significantly between LPS-1 and C quarters after the challenge. In LPS-3 quarters SCC levels increased within the first 12 h, reached peak levels between 12 and 36 h (P ≤ 0.001) and decreased (P ≤ 0.05) thereafter to reach baseline at 108 hours. Lactose in LPS-3 quarters decreased (P ≤ 0.05) to a minimum at 24 h and increased slightly thereafter while EC, Na, and Cl increased transiently in response to LPS-3. WBC and PMN levels in both groups decreased numerically within 24 h after LPS administration. In LPS-1, WBC at 24, 48 and 108 h were significantly lower whereas in LPS-3 they were significantly higher than at time 0. TNFα-mRNA expression in both groups did not change in response to IM LPS-challenge. IL-1β-mRNA expression at 12, 24 and 36 h in LPS-1 quarters increased significantly as compared to time 0. In LPS-3 quarters the mRNA expression values of all tested ILs increased significantly as compared to time 0 within 12 h after LPS-challenge. IL-1β-mRNA expression decreased (P ≤ 0.05) at 48 and 84 h in LPS quarters. IL-8 mRNA was significantly decreased at 84 h after challenge in LPS-3 quarters. COX-2-mRNA expression in LPS-1 quarters decreased significantly as compared to time 0 at 48, 84 and 108 h, with a minimum at 84 h (P ≤ 0.05). In LPS-3 quarters COX-2-mRNA levels increased (P ≤ 0.05) within 48 h after the LPS-challenge. Experiment II: Six cows (5 German Braunvieh, 1 Brown Swiss) were injected in one quarter with 100 μg LPS and in the contralateral quarter with saline (9 g/l; C). Mammary biopsy samples of both quarters were taken immediately before and at 3, 6, 9 and 12 h after infusion and mRNA expression of TJ proteins occludin (OCLN) and zonula occludens (ZO-) 1, 2 and 3 were quantified by real-time RT-PCR. OCLN-mRNA expression did not change in response to the IM infusion while that of ZO-1, ZO-2 and ZO-3 decreased significantly within six hours. In conclusion, a dose of 1 μg LPS did not initiate a immune response in the mammary gland. Furthermore the dose of 100 μg of LPS enhanced TJ permeability by reducing TJ plaque proteins density.

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Effect of Once Daily Milking and Concurrent Somatotropin on Mammary Tight Junction Permeability and Yield of Cows

Cited by 79 publications

References 10 publications

Use of milk epithelial cells to study regulation of cell activity and apoptosis during once-daily milking in goats

Use of milk epithelial cells to study regulation of cell activity and apoptosis during once-daily milking in goats

Severe feed restriction increases permeability of mammary gland cell tight junctions and reduces ethanol stability of milk

Dose-dependent immune response in milk cells and mammary tissue after intramammary administration of lipopolysaccharide in dairy cows

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