• Evaluation of on-farm labour saving strategies for optimisation of herd size that could be managed by one operator

      O'Brien, Bernadette; Gleeson, David E; Shalloo, Laurence (Teagasc, 2009-06-01)
      Alternative milking frequencies Once a day (OAD) milking throughout lactation of a herd (over 2 years, incorporating 24% heifers) resulted in loss in milk solids (MS) production of 17% per cow.  Milking cows OAD in their 1st lactation does not adversely impact on milk production in the second lactation, when changed to twice a day (TAD) milking but may lead to a higher mastitis incidence.  Changeover in milking frequency in mid lactation resulted in a similar yield of MS per cow for TAD milking for the full lactation (474 kg) and the TAD OAD group (TAD for the first 110 days and OAD for the remainder of the lactation) (469 kg).  Thirteen times weekly milking in late lactation (omitting the Sunday evening milking) compared to twice daily milking every day had no effect on milk yield or composition and maximum SCC observed during the trial was 270x103 cells/ml.  Once daily milking did not adversely affect the processability of milk.  Once daily milking did not significantly increase milk SCC levels. Alternative calf rearing systems  The improved efficiency increased herd size may be due to less use of buckets for calf feeding together with more frequent use of teat feeding from a container, automatic feeders and ad libitum feeding  A study on OAD calf feeding (whole milk) demonstrated that calves can be reared with a OAD milk feeding system and weaned early (42 days) without adversely affecting performance  There was no difference in the live-weight gain of calves on once daily feeding, twice daily feeding or once daily feeding going outdoors after 28 days  Calf liveweight gain was greater with once daily feeding with milk replacer compared to once daily feeding with whole milk or once daily feeding with milk replacer going outdoors after 28 days Economic analysis of alternative milking systems  When deciding on the type, size and level of technology in the milking parlour, the trade-off between labour requirement and cost and the initial capital investment requirement should be key in making the decision.
    • Impact of agronomic practices of an intensive dairy farm on nitrogen concentrations in a karst aquifer in Ireland

      Huebsch, Manuela; Horan, Brendan; Blum, P.; Richards, Karl G.; Grant, Jim; Fenton, Owen; Teagasc Walsh Fellowship Programme (Elsevier, 24/09/2013)
      Exploring the relationship between agricultural nitrogen loading on a dairy farm and groundwater reactive nitrogen concentration such as nitrate is particularly challenging in areas underlain by thin soils and karstified limestone aquifers. The objective of this study is to relate changes in detailed agronomic N-loading, local weather conditions, hydrogeological and geological site characteristics with groundwater N occurrence over an 11-year period on an intensive dairy farm with free draining soils and a vulnerable limestone aquifer. In addition, the concept of vertical time lag from source to receptor is considered. Statistical analysis used regression with automatic variable selection. Four scenarios were proposed to describe the relationships between paddock and groundwater wells using topographic and hydrogeological assumptions. Monitored nitrate concentrations in the studied limestone aquifer showed a general decrease in the observed time period (2002–2011). Statistical results showed that a combination of improved agronomic practices and site specific characteristics such as thicknesses of the soil and unsaturated zone together with hydrogeological connections of wells and local weather conditions such as rainfall, sunshine and soil moisture deficit were important explanatory variables for nitrate concentrations. Statistical results suggested that the following agronomic changes improved groundwater quality over the 11-year period: reductions in inorganic fertiliser usage, improvements in timing of slurry application, the movement of a dairy soiled water irrigator to less karstified areas of the farm and the usage of minimum cultivation reseeding on the farm. In many cases the explanatory variables of farm management practices tended to become more important after a 1- or 2-year time lag. Results indicated that the present approach can be used to elucidate the effect of farm management changes to groundwater quality and therefore the assessment of present and future legislation implementations.