A New Direction for the Payment of Milk: Technological and Seasonality Considerations in Multiple Component Milk Pricing of Milk (Liquid and Manufacturing) for a Diversifying Dairy Industry

End of project reportThe main objectives of this study were to compare a Multiple Component Pricing system with the current milk pricing practice in Ireland and to estimate the marginal values of the three main milk components (fat, protein and lactose) in the context of the Irish milk processing industry. A representative linear programming model of an average Irish milk processor was developed in order to determine the marginal values of the milk components and to compare the value of milk under the Multiple Component Pricing system with the value under the current milk pricing practice. This study also examined the effect of product mix, milk supply and milk composition on the marginal value of the milk components

A note on the design and testing of single teatcups for automatic milking systems

peer-reviewedIn automatic milking units single independent teatcups or shell/liner combinations are required. The milking characteristics of three designs of single-teatcup milking units were compared with a conventional milking unit in a pipeline milking system. The combined weight of each single-teatcup shell and liner used in the single-teatcup units was 0.18 kg, 0.38 kg or 0.56 kg. The conventional milking cluster had a claw volume of 150 mL and a weight of 3.16 kg. The single sets of teatcups were applied manually and removed automatically when milk flow from the four teatcups reached 0.2 kg/min. The experiment involved a latin square design with four groups of Friesian cows (10 cows/group), four 2-day periods and four treatments. At a flow rate of 4 L/min during simulated milking the mean vacuum level at the teat-end (artificial teat) during the “bphase” of pulsation was 43.8 kPa with the conventional milking unit and 33 kPa for the three single-teatcup units. The corresponding mean and minimum teat-end vacuum in the “d-phase” were 38.46 kPa and 29.54 kPa, respectively, for the conventional system and 24.95 kPa and 17.59 kPa, respectively, for the single-teatcup configuration. The light teatcup (weight 0.18 kg) gave longer time to milk letdown, longer milking time and both lower peak and average milk flow than the conventional cluster

A serological survey of ruminant livestock in Kazakhstan during post-Soviet transitions in farming and disease control

The results of a serological survey of livestock in Kazakhstan, carried out in 1997–1998, are reported. Serum samples from 958 animals (cattle, sheep and goats) were tested for antibodies to foot and mouth disease (FMD), bluetongue (BT), epizootic haemorrhagic disease (EHD), rinderpest (RP) and peste des petits ruminants (PPR) viruses, and to Brucella spp. We also investigated the vaccination status of livestock and related this to changes in veterinary provision since independence in 1991. For the 2 diseases under official surveillance (FMD and brucellosis) our results were similar to official data, although we found significantly higher brucellosis levels in 2 districts and widespread ignorance about FMD vaccination status. The seroprevalence for BT virus was 23%, and seropositive animals were widespread suggesting endemicity, despite the disease not having being previously reported. We found a few seropositives for EHDV and PPRV, which may suggest that these diseases are also present in Kazakhstan. An hierarchical model showed that seroprevalence to FMD and BT viruses were clustered at the farm/village level, rather than at a larger spatial scale. This was unexpected for FMD, which is subject to vaccination policies which vary at the raion (county) level

In memoriam: Ralph McInerny (1929-2010)

Obituari

A study of the somatic cell count (SCC) of Irish milk from herd management and environmental perspectives

End of project reportThe objective of this study was to investigate the herd management practices associated with somatic cell count (SCC) and total bacteria count (TBC), to geographically analyse SCC on a national basis, to investigate cow factors associated with SCC and to estimate the milk loss associated with high SCC across parities. From the 400 farms surveyed during farm visits throughout spring and winter, a profile of herd management was developed and the associations between management practices and milk SCC and TBC were established. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme, the use of teat disinfection post-milking, a higher frequency of cleaning and increased farm hygiene. Management practices associated with low TBC included the use of heated water in the milking parlour, participation in a milk recording scheme, tail clipping of cows at a frequency greater than once per year and increased farm hygiene. The spatial analysis showed that the south of the country had the greatest density of milk-recording herds. Approximately 60% of all herds in the study were from four counties (Cork, Kerry, Limerick and Tipperary). Average bulk tank SCC increased from 110,264 cells/mL in 2003 to 118,782 cells/mL in 2005, followed by a decrease to 108,454 cells/mL in 2007. Spatial clustering of high SCC scores was not observed (i.e., SCC on one farm was not related to SCC on other farms), which is consistent with mastitis being a herd problem as opposed to an area-based problem. SCC increased with parity from 97,000 cells/mL in parity 1 to 199,000 cell/mL in parity 6. SCC decreased between the period 5 to 35 days in milk (DIM) and 36 to 65 DIM, and increased thereafter. Cows calving in the months of January and September were associated with lower average 305 day SCC. The rate of increase in SCC from mid to late lactation was greatest in older parity animals. There was a test day milk loss of 1.43, 2.08, 2.59, 2.56 and 2.62 litres (parities 1 to 5, respectively) associated with an increase of SCC category from 400,000 cells/mL. When SCC was adjusted (test day SCC/dilution estimate, and test day SCC + (-ß)(test day milk yield)) to account for milk yield, similar trends in milk loss were observed. Alternatively, adjusting SCC (SCC*test day milk yield/mean test day milk yield) to account for milk yield showed an increase in test day milk with increasing SCC category. The results from this study highlight that adherence to best milking/farming practice will help reduce SCC and TBC on farms. The results contribute to the knowledge relating to SCC through increasing the accuracy of milk loss due to SCC and management practices associated with SCC. The results in the study can also be used in the development of strategies to reduce SCC on farms

Differences in the epidemiology of theileriosis on smallholder dairy farms in contrasting agro-ecological and grazing strata of highland Kenya

A prospective cohort study was conducted in five purposively-sampled agro-ecological zone (AEZ)-grazing system strata in Murang’a District, Kenya, between March 1995 and June 1996. The study strata were selected based on a preliminary characterization study to represent the widest range of risks to East Coast fever (ECF) in the District and included zero-grazing and open-grazing farms. In total, 225 calves from 188 smallholder farms were examined from birth to 6 months of age and visited within the first 2 weeks of life and thereafter at bi-weekly intervals for up to 14 visits. The purpose of the study was to characterize the differences in epidemiology (risks of infection, morbidity and mortality) and potential control of ECF between the selected strata. Evidence of Theileria parva infection was assessed by increased antibody levels as measured in an indirect ELISA assay by the percent positivity (PP) of serum samples relative to a strong positive reference serum. Sero-conversion risks of T. parva were highest in the open-grazing strata. Antibody prevalence in adult cattle and ECF morbidity and mortality risks were also highest in open-grazing strata. While different, all five AEZ-grazing strata were considered to be endemically unstable for ECF. East Coast fever challenge was low in all zero-grazing strata and this challenge is likely to remain low due to continuing intensification of smallholder farming in the central highlands. In the open-grazing strata, there was higher challenge and a greater impact of ECF. ILRI publication no.: 99017

A study of factors affecting the efficiency of milking operations.

End of Project ReportWith a mid-level milking system the milking time was reduced significantly when the teat end vacuum was increased • Vacuum losses were lower and milking time was shorter with simultaneous pulsation than with alternate pulsation • Milk yield was not affected by the magnitude of teat end vacuum. • Both the mean flowrate and peak flowrate increased when the teat end vacuum was increased. • New milking plants and conversions should have 16 mm bore long milk tubes (LMT) and 16 mm bore entries in the milk pipeline • The omission of udder washing as a pre-milking preparation procedure did not influence milking characteristics. • TBC and E. coli were significantly reduced with full pre-milking preparation compared to no pre-milking preparation when milk was produced from cows on pasture • Counts for individual bacterial species were well below maximum numbers permitted in EU Council Directive (Anon. 1992) when no pre-milking preparation was carried out

Epidemiological patterns of hepatitis B virus (HBV) in highly endemic areas

This paper uses meta-analysis of published data and a deterministic mathematical model of hepatitis B virus (HBV) transmission to describe the patterns of HBV infection in high endemicity areas. We describe the association between the prevalence of carriers and a simple measure of the rate of infection, the age at which half the population have been infected (A50), and assess the contribution of horizontal and perinatal transmission to this association. We found that the two main hyper-endemic areas of sub-Saharan Africa and east Asia have similar prevalences of carriers and values of A50, and that there is a negative nonlinear relationship between A50 and the prevalence of carriers in high endemicity areas (Spearman's Rank, P = 0·0086). We quantified the risk of perinatal transmission and the age-dependent rate of infection to allow a comparison between the main hyper-endemic areas. East Asia was found to have higher prevalences of HBeAg positive mothers and a greater risk of perinatal transmission from HBeAg positive mothers than sub-Saharan Africa, though the differences were not statistically significant. However, the two areas have similar magnitudes and age-dependent rates of horizontal transmission. Results of a simple compartmental model suggest that similar rates of horizontal transmission are sufficient to generate the similar patterns between A50 and the prevalences of carriers. Interrupting horizontal transmission by mass immunization is expected to have a significant, nonlinear impact on the rate of acquisition of new carriers

The role of intratidal oscillations in sediment resuspension in a diurnal, partially mixed estuary

Using detailed observations of the mean and turbulent properties of flow, salinity and turbidity that spanned 2001/02, we examined the physical mechanisms underpinning sediment resuspension in the low-energy Swan River estuary, Western Australia. In this diurnal tidally-dominated estuary, the presence of intratidal oscillations, a tidal inequality lasting 2 to 3 hours on the flood tide, generated by interactions of the four main diurnal and semidiurnal astronomical constituents, K₁, O₁, M₂, and S₂, played a major role in modifying vertical stratification and mixing. These intratidal oscillations are controlled by phase differences between the tropic and synodic months rather than being temporally-fixed by bed friction, as occurs in semidiurnal estuaries. Intratidal oscillations are largest, at around 0.1 m, near to the Austral solstice when the lunar and solar declination are in-phase. Despite the seemingly small change in water level, shear-induced interfacial mixing caused destratification of the water column with the top-to-bottom salinity (ΔS) difference of 3.5 present early in the flood tide eroded to less than 0.3 by the end of the intratidal oscillation. High turbidity peaks, of 250 nephelometric turbidity units, coincided with these intratidal oscillations and could not be explained by bed friction since shear stress from mean flow did not exceed threshold criteria. High Reynolds stresses of ∼1 Nm⁻² did, however, exceed τcr and together with negative Reynolds fluxes indicate a net downward transport of material. Destratification of the water column induced by shear instabilities resulted in large overturns capable of moving in situ material towards the bed during intratidal oscillations and these turbidities were ∼10 times greater than those from bed-generated resuspension observed later during the flood tide