Date of Award

2024

Document Type

Master Thesis

Degree Name

Masters of Science (Research)

Department

BIOLOGICAL SCIENCES

First Advisor

Dr. Craig Murphy

Second Advisor

Dr. Emer Kennedy

Third Advisor

Dr. Michael O’Donovan

Abstract

The current perception of dairy farming in Ireland is one of long hours, physically demanding work and poor remuneration, especially when compared to that of a modern, high-tech industry with career opportunities and advancement possibilities at many levels (Teagasc, 2018). One of the biggest factors in attracting and retaining people to work on Irish dairy farms is that they must be desirable places to work (Teagasc, 2018). Milking is the most labour demanding task on Irish dairy farms (Deming et al., 2018) and one, which necessitates farmers being present on the farm twice daily if milking twice-a-day (TAD). Altering milking frequency, such as milking once-a-day (OAD) would provide more flexibility for farmers and allow for a better work life balance, potentially making dairy farms a more attractive workplace. The first objective of this thesis was to compare OAD and TAD milking on differences in milk production and composition, grazing dry matter intake, health and welfare. While recognizing full-time OAD may not be suitable for all farmers, the second objective of the thesis was to investigate the effect of short- term OAD milking for four (OAD4), six or eight-weeks directly post-calving compared to milking TAD on i) immediate milk production and the effects when cows returned to TAD milking and ii) cow health and welfare. Milking cows OAD on a fulltime basis reduced cumulative milk yield by 26% and milk solids yield (MSY) by 21% compared to TAD, in part due to a shorter lactation length (9.7 days). Milk fat % of cows milked TAD was similar for all three years of the study (5.05%) while milk fat % of the cows milked OAD increased year on year (5.02, 5.32 and 5.70% for year 1, 2 and 3; respectively). Milk protein % was greater (+0.19%) for cows milked OAD compared with TAD which was 3.78%. Total dry matter intake for cows milked OAD was 22 % less at the start of lactation (< 167 days) than cows milked TAD, but as lactation progressed there was no difference in dry matter intake (DMI) between treatments. Milking cows OAD significantly increased average somatic cell score SCS during (+16%) and at the end of lactation (+19%), compared with TAD milking. Milking OAD also resulted in greater bodyweight, body condition score and fertility performance including a reduced milking time per cow per day and milking time per litre of milk.

Milking OAD for the first four-weeks of lactation compared to TAD reduced milk yield by 21%. When OAD milking continued until week six or eight of lactation, milk yield reduction increased to 24 and 26%, respectively, compared to TAD. Following the 35- week lactation, cumulative milk yield of the TAD and OAD4 treatments were similar. There was no difference in MSY between treatments at the end of lactation. During the first four weeks of lactation milking cows OAD increased (+ 0.95 units) SCS compared to cows being milked TAD (3.26 units); there was no effect on SCS from week five of lactation onwards. Milking OAD reduced milking time (up to 35% less) and increased the likelihood of milk leakage from udders, compared to TAD. The results of this study indicate that OAD milking for the first four-weeks in early lactation may be a viable option to reduce labour requirements, without having a negative impact on cow milk production or welfare indicators. However, the significant time saving and potential savings in costs (e.g., electricity) with fulltime OAD milking need to be considered in conjunction with reductions in milk production when considering, OAD milking for the entire lactation.

Access Level

info:eu-repo/semantics/openAccess

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