Once-daily milking effects in high-yielding Alpine dairy goats

Komara, Moussa; Boutinaud, Marion; Chedly, Hedi Ben; Guinard-Flament, Jocelyne; Marnet, Pierre‐Guy

doi:10.3168/jds.2009-2179

Cited by 26 publications

(25 citation statements)

References 16 publications

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“…In the present trial, we did not observe a time-dependent effect, as milk yield loss was found to be constant over the 5-week ODM period. This is consistent with the observations of Komara et al (2009), but not with our previous observations (Ben Chedly et al, 2011) or those of Salama et al (2003), in which milk yield loss was greater during the first weeks of ODM. This difference is likely attributable to the longer experimental period in those studies (15 and 24 weeks, respectively).…”

Section: Discussionsupporting

confidence: 88%

The decrease in milk yield during once daily milking is due to regulation of synthetic activity rather than apoptosis of mammary epithelial cells in goats

Chedly

Lacasse

Marnet

et al. 2013

Animal

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Once daily milking (ODM) is a management practice that can improve working conditions and reduce production costs in dairy farming compared with twice daily milking (TDM). However, ODM is associated with a decrease in milk yield. Previous research indicated that disruption of tight junctions in the mammary gland may be one of the regulatory factors involved in the milk yield decrease observed during ODM. The aim of this study was to investigate the involvement of mammary epithelium disruption in the regulation of the activity and dynamics of mammary epithelial cells (MEC) during 5 weeks of ODM in goats. Twelve alpine goats (producing 3.67 ± 0.64 kg/day and 47 ± 1.6 days in milk) were assigned to two groups that were milked once or twice a day during 5 weeks and then switched back to TDM. Mammary biopsies were collected before and on days 2 and 16 of both ODM and TDM switchback periods. Milk purified epithelial cells were collected before and on days 1, 7, 21 and 28 during ODM as well on days 1 and 7 of the TDM switchback period. The mRNA levels of genes involved in the regulation of synthetic activity and apoptosis were analysed by RT-PCR in milk MEC and mammary biopsies. ODM decreased yields of milk (−23%), lactose (−23%) and casein (−16%). Lactose synthesis was regulated at the transcriptional level by downregulation of α-lactalbumin mRNA levels in both biopsy samples (−30%) and milk MEC (−74%). TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling) staining of mammary gland biopsies did not show any increase in cell apoptosis after 2 and 16 days of ODM (0.8% and 1%, respectively) despite upregulation of Bax mRNA levels in milk MEC. This suggests that the decrease in milk yield observed during ODM is attributable to a decrease in synthetic activity rather than to induction of MEC cell death. ODM induced the disruption of tight junctions in the mammary gland only on the first day of the treatment as indicated by increased blood lactose concentration. This indicates that the decrease in MEC activity observed over the 5 weeks of ODM was not due to disruption of the mammary gland tight junctions. There was no carryover effect of 5 weeks of ODM on milk production. Therefore, it appears that the decrease in milk yield that occurs during ODM in goats is due to regulation of synthetic activity rather than to apoptosis of MEC.

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Section: Discussionsupporting

confidence: 88%

The decrease in milk yield during once daily milking is due to regulation of synthetic activity rather than apoptosis of mammary epithelial cells in goats

Chedly

Lacasse

Marnet

et al. 2013

Animal

Self Cite

View full text Add to dashboard Cite

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“…For example, in the Murciano-Granadine breed, Salama et al (2003) found no differences in the SCC of tank milk by comparing one milking per day (1X) and two milkings a day (2X), although the SCN level was increased. On the other hand, Komara et al (2009), in two experiments realized with Alpine breed goats, found that only one of them, considering only multiparous goats, had an increase in counts going from 2X to 1X (179,800 and 400,300 cells mL -1 , respectively). These results could suggest that high yielding goats or specific breeds cannot be adapted to 1X (Komara et al, 2009).…”

Section: Milking Frequencymentioning

confidence: 96%

Factors affecting somatic cell count in dairy goats: a review

Jiménez-Granado

Sánchez-Rodríguez

Arce

et al. 2014

Span. j. agric. res.

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Somatic cell count (SCC) in monitoring udder health has been described in numerous studies as a useful method for the diagnosis of intramammary infection (IMI), and it is considered in standards of quality and hygiene of cow's milk in many countries. However, several authors have questioned the validity of SCC as a reliable IMI diagnosis tool in dairy goats. This review attempts to reflect the importance of different infectious and non-infectious factors that can modify SCC values in goat milk, and must, therefore, be taken into account when using the SCC as a tool in the improvement of udder health and the quality of milk in this species. In dairy goats, some investigations have shown that mammary bacterial infections are a major cause of increased SCC and loss of production. In goats however, the relationship between bacterial infections and SCC values is not as simple as in dairy cattle, since non-infectious factors also have a big impact on SCC. Intrinsic factors are those that depend directly on the animal: time and number of lactation (higher SCC late in lactation and in aged goats), prolificity (higher SCC in multiple births), milking time (higher SCC in evening compared to morning milking) and number of milkings per day, among others. Extrinsic factors include: milking routine (lower SCC in machine than in manual milking), seasonality and food. In addition, milk secretion in goats is mostly apocrine and therefore characterized by the presence of epithelial debris or cytoplasmic particles, which makes the use of DNA specific counters mandatory. All this information is of interest in order to correctly interpret the SCC in goat milk and to establish differential SCC standards.Additional key words: infectious and non-infectious factors; milk quality; mastitis; benchmarking.

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“…The goats thus received 800 g alfalfa, 1 kg energy concentrate and ad libitum hay and water, each day. The diet and the milking routines and equipment were previously described by Komara et al (2009). The goats in the TDM were milked at 0645 h and 1645 h, whereas those in ODM were milked at 1645 h.…”

Section: Animals and Experimental Designmentioning

confidence: 99%

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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Once-daily milking effects in high-yielding Alpine dairy goats

Cited by 26 publications

References 16 publications

The decrease in milk yield during once daily milking is due to regulation of synthetic activity rather than apoptosis of mammary epithelial cells in goats

The decrease in milk yield during once daily milking is due to regulation of synthetic activity rather than apoptosis of mammary epithelial cells in goats

Factors affecting somatic cell count in dairy goats: a review

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

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