Search

Your search keyword '"Phyn, C.V.C."' showing total 44 results
Start Over Author "Phyn, C.V.C."
44 results on '"Phyn, C.V.C."'

28. Specificity of two peripartum blood markers for early lactation acute uterine inflammation in pasture-fed, seasonal-calving dairy cows.

Author

Spaans, O.K., Roche, J.R., Burke, C.R., Phyn, C.V.C., McDougall, S., Reed, C.B., Kuhn-Sherlock, B., Hickey, A., Heiser, A., and Crookenden, M.A.

Abstract

A delayed recovery of the reproductive tract from natural inflammatory processes associated with postpartum involution will compromise further reproductive function. Following a literature review, we selected serum amyloid A (SAA) and α1-acid glycoprotein (α1-AGP) to assess as potential circulating markers of acute uterine inflammation, as concentrations of these 2 acute phase proteins were reported to be elevated early postpartum in dairy cows with active uterine infection. Convenience serum samples from an induced model of uterine infection were used to measure concentrations of these markers. Infection was induced by infusing either 107or 109cfu of Trueperella pyogenes(n = 9 cows each; bacteria group n = 18) or saline as a control (n = 18) into the uterus at 48 d postpartum. Although infection stimulated an increase in uterine polymorphonuclear neutrophils, SAA and α1-AGP concentrations in serum were not different between infusion groups. Cows were subsequently classified into uterine health groups based on the presence of endometritis, with or without the presence of T. pyogenesin uterine culture in response to uterine infusion. Mean SAA concentrations were greater in cows that were either endometritis negative – infection positive (n = 9), endometritis positive – infection negative (n = 5), or endometritis positive – infection positive, compared with the endometritis negative – infection negative (n = 11) cows. There was no difference between uterine health groups for α1-AGP concentrations. Mean SAA and α1-AGP concentrations changed over time, reaching maximum concentrations on d 3 and 7 post-infusion, respectively, before decreasing thereafter to d 17 post-infusion.

Published
2024
Full Text
View/download PDF

29. Reduced milking frequency: Milk production and management implications

Author

Phyn, C.V.C., Davis, S.R., Guinard-Flament, Jocelyne, Pomiès, Dominique, Roche, J.R., Kay, J.K., and Stelwagen, Kerst

Subjects
fréquence de la traite, milking frequency, reproduction, nutrition, milk yield, once-day milking, dairy cow, santé animale, stade de lactation, food and beverages, bien-être animal, monotraite, Agricultural sciences, bovin laitier, vache laitière, race bovine, composition du lait, métabolisme, Sciences agricoles, Autre (Sciences du Vivant)
Abstract

Most dairy cows throughout the world are milked twice daily. In intensive dairying systems, however, it is not uncommon to increase milking frequency to between 3 and 6 times daily to increase milk production. Reducing milking frequency is much less common; however, once-daily milking of dairy cows, practiced either strategically during certain parts of the lactation or for the entire lactation, is not uncommon in key dairying countries where less emphasis is placed on milk production per cow. The practice fits well with more extensive dairy production systems, particularly those based on grazed pasture. A feature of once-daily milking is that it reduces milk yield by approximately 22%, depending on stage of lactation, breed, and parity, and it may adversely affect lactation length and persistency. However, it can offer several positive farm management options, especially related to labor requirements and farm working expenses. In addition, it may provide a tool to better manage the metabolism and energy balance of cows during early lactation or during periods of pasture deficit, and it may help to improve reproductive performance and animal health and welfare. Once-daily milking, representing one extreme of the mammary function spectrum, has attracted considerable research interest over the years. Consequently, substantial scientific information is available on its effects on mammary function, at both the physiological and molecular levels. This review focuses instead on the management of the cow milked once daily, covering the production response in relation to breed, stage of lactation, and parity, and its effect on energy status, reproduction, health and welfare, as well as on milk composition and processability.

Published
2013

41. cDNA Microarray Analysis Reveals that Antioxidant and Immune Genes Are Upregulated During Involution of the Bovine Mammary Gland

Author

Singh, K., primary, Davis, S.R., additional, Dobson, J.M., additional, Molenaar, A.J., additional, Wheeler, T.T., additional, Prosser, C.G., additional, Farr, V.C., additional, Oden, K., additional, Swanson, K.M., additional, Phyn, C.V.C., additional, Hyndman, D.L., additional, Wilson, T., additional, Henderson, H.V., additional, and Stelwagen, K., additional

Published
2008
Full Text
View/download PDF

44. Associations between peripartum lying and activity behaviour and blood non-esterified fatty acids and β-hydroxybutyrate in grazing dairy cows.

Author

Hendriks, S.J., Phyn, C.V.C., Turner, S-A., Mueller, K.R., Kuhn-Sherlock, B., Donaghy, D.J., Huzzey, J.M., and Roche, J.R.

Abstract

• Behaviour of metabolically challenged grazing dairy cows was investigated. • Metabolically challenged cows lay less and walked more before calving. • Cows experiencing a metabolic challenge were also less active postcalving. • Cows divergent in metabolic status have different behaviour patterns to healthy cows. • Monitoring behaviour may allow metabolically challenged cows to be identified. During early lactation, most dairy cows experience negative energy balance (NEB). Failure to cope with this NEB, however, can place cows at greater risk of developing metabolic disease. Our objective was to characterise, retrospectively, lying behaviour and activity of grazing dairy cows grouped according to blood non-esterified fatty acids (NEFAs) and β-hydroxybutyrate (BHB) as indicators of postpartum metabolic state. Blood was sampled weekly for up to 4 weeks precalving, on the day of calving (day 0), daily between 1 and 4 days postcalving, and then at least weekly between week 1 and week 5 postcalving for analysis of plasma NEFAs and BHB concentrations. Two hundred and forty-four multiparous Holstein-Friesian and Holstein-Friesian × Jersey cows were classified into one of three metabolic status groups based on maximum blood NEFAs and BHB concentrations during week 1 and 2 postcalving. A cow was classified as having either: (1) low NEFAs and low BHB (Lo–Lo ; n = 78), when all blood samples were <1.0 mmol/L for NEFAs and ≤1.0 mmol/L for BHB during the first 2 weeks postcalving; (2) high NEFAs and low BHB (Hi–Lo ; n = 134), when blood NEFAs were ≥1.0 mmol/L and blood BHB was ≤1.0 mmol/L at the same sampling time point during the first 2 weeks postcalving; or (3) high NEFAs and high BHB (Hi–Hi ; n = 32), when blood NEFAs were ≥1.0 mmol/L and blood BHB was ≥1.2 mmol/L at the same sampling time point during the first 2 weeks postcalving. Accelerometers (IceTag or IceQube devices; IceRobotics Ltd.) were used to monitor lying and activity behaviours peripartum (–21 to +35 days relative to calving). Changes in lying behaviour and activity occurred before the mean day that cows were classified Hi–Hi and Hi–Lo (2.2 and 3.5 d postcalving, respectively). Up to 3 weeks preceding calving, Hi–Hi cows were more active, had fewer daily lying bouts (LB s), and spent less time lying than Lo–Lo cows. In addition, Hi–Hi cows had fewer daily LBs and were less active up to 4 weeks postcalving than Lo–Lo cows, but these differences were biologically small. Groups of grazing cows classified as experiencing a more severe metabolic challenge behave differently up to 3 weeks precalving than their herdmates with lower blood NEFAs and BHB postcalving. These altered behaviours may allow identification of individual cows at risk of a metabolic challenge, but further research is required. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results