• The association between herd- and cow-level factors and somatic cell count of Irish dairy cows

      McParland, Sinead; O'Brien, Bernadette; McCarthy, J.; Department of Agriculture, Food and the Marine; 10/RD/AAQUALITYMILK/TMFRC713 (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Somatic cell count (SCC) is an indicator of both udder health and milk quality and is measured at an animal level through national milk recording schemes. The objective of this study was to assess the animal and herd factors contributing to elevated SCC (i.e. poorer milk quality). Test day records (n = 2,658,928) from 519,456 cow lactations obtained between 2007 and 2011 were included in the analyses. Herd factors tested included the geographical region of the herd and production system operated (spring calving or mixed calving system). Animal factors tested included breed, parity and age nested within parity. Four definitions of normalised SCC (i.e. SCS) were considered: 1) average test-day SCS within a 24 hour period (TD_SCS), 2) maximum SCS (peak_SCS), 3) minimum SCS (min_SCS), and 4) average SCS (avg_SCS) recorded across cow lactation; in addition, the proportion of test day records with an SCC count >200,000 (prop_200) or >250,000 (prop_250) within cow lactation were included. Following adjustment for fixed effects, average TD_SCS was 179,308 cells per mL while avg_SCS, and average min_SCS and peak_SCS were 119,481, 50,992 and 298,813 cells per mL, respectively. All animal and herd factors had a significant effect on SCC. Older animals, animals which were younger at calving than contemporaries and Holstein animals had higher SCC than younger alternative breed animals who calved at the median age. In addition, mixed calving production systems and herds in Connaught had higher SCC than spring calving herds in the other regions of Ireland.
    • Examining the impact of mastitis on the profitability of the Irish dairy industry

      Geary, Una; Lopez-Villalobos, N.; O'Brien, Bernadette; Garrick, Dorian J.; Shalloo, Laurence (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Mastitis was identified as a priority disease within the Irish dairy industry by both dairy farmers and industry animal health experts, which led to the development of the CellCheck programme. In order to support this programme it was necessary to understand the extent to which mastitis affects farm profit, processor returns and ultimately industry profitability. To this end, an analysis of the impact of mastitis on farm, processor and the overall industry profitability was carried out. The impact of mastitis on farm costs, farm receipts and farm profitability is presented across a range of bulk milk somatic cell count (SCC) categories from <100,000 to >400,000 cells/mL. A meta-analysis of the relationship between SCC and raw milk composition, cheese processing characteristics and cheese composition was carried out and utilised to establish the impact of mastitis on processor returns. As SCC increased, the impact of mastitis on the volume of product that could be produced, net processor returns, milk price and the values per kg of fat and protein were calculated. The farm and processor analysis were then combined to estimate the impact of mastitis on the Irish dairy industry returns, accounting for both farm and processor costs. The analysis suggests that as cell count reduced from >400,000 to <100,000 cells/mL, overall returns to the farm should increase by 4.8 c/L, including the farm and processor related effects. Nationally, if the cell count was reduced by 10%, it would be worth €37.6 million for the Irish dairy industry.
    • Iodine concentrations in milk

      O'Brien, Bernadette; Gleeson, David E; Jordan, Kieran; Irish Dairy Levy Research Trust (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Iodine tends to be supplemented at farm level in the expectation of increasing cow health and fertility. There is concern that such practices may result in high milk iodine, which could affect ingredients for infant formula and, thus, dairy export markets. The objective of this study was to quantify the effect of iodine fortified feed and teat disinfection practices of dairy cows on milk iodine concentration. Thirty lactating cows were fed 7 kg, 3 kg (10 mg iodine/kg) and 0 kg of concentrate feed during 3 periods of 35 days each. During the first 14 days of each period, cows were on dietary iodine treatments only; during days 15–21, one of three teat disinfection treatments (n = 10) was applied (in addition to the dietary iodine treatments): non-iodine (chlorhexidine) post-milking spray; 0.5% iodine spray post-milking; 0.5% iodine spray pre- and post-milking. Cow milk yield was 21.3 kg/day. Individual cow milk samples were analysed for iodine concentration on 2 days at the end of each treatment period. Dietary supplementation of iodine at both 30 mg and 70 mg/day, when compared to the diet with no supplement, increased milk iodine concentrations significantly (P < 0.001) from 449 to 1034 and 915 μg/kg, respectively. Teat disinfection both pre- and post-milking increased milk iodine concentration at each of the dietary supplementation levels of 0, 30 and 70 mg/day compared with a non-iodine teat disinfectant (P < 0.001). In conclusion, both dietary iodine supplementation and teat disinfection iodine increased milk iodine concentrations in an additive manner, exceeding common target values of 250 μg/kg. As both iodine treatments can occur simultaneously on farm, supplementation strategies should be monitored.
    • Meta-analysis to investigate relationships between somatic cell count and raw milk composition, Cheddar cheese processing characteristics and cheese composition

      Geary, Una; Lopez-Villalobos, N.; O'Brien, Bernadette; Garrick, Dorian J.; Shalloo, Laurence (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      The relationship between elevated somatic cell count (SCC) and raw milk composition, cheese processing and cheese composition, was investigated by meta-analysis using available literature representing 45 scientific articles. With respect to raw milk composition there was a significant positive relationship between SCC and the protein and fat contents and a significant negative relationship between SCC and the lactose content. In relation to cheese processing, there was a significant negative relationship between SCC and recoveries of protein and fat. As SCC increased cheese protein content declined and cheese moisture content increased.
    • Protocols and strategies to study the migration of veterinary drug residues into milk and dairy products in licensed trials

      Power, C.; Sayers, Riona; O'Brien, Bernadette; Furey, A.; Danaher, Martin; Jordan, Kieran (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      In the interest of animal welfare, and in order that the results from animal trials are considered valid for inclusion in the development of regulations, it is necessary that such trials are undertaken in accordance with the appropriate licensing arrangements. In January 2013, new licensing arrangements were introduced in the European Union. The aim of this paper is to outline the legislative strategy required for obtaining licences for animal trials and based on live animal trials with flukicides, establishes a blueprint for obtaining the appropriate licences and undertaking the experiments.
    • Review of studies on flukicide residues in cows’ milk and their transfer to dairy products

      Power, C.; Sayers, Riona; O'Brien, Bernadette; Furey, A.; Danaher, Martin; Kieran, Jordan; Teagasc Walsh Fellowship Programme (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Flukicides are widely used to treat infestations of liver fluke in dairy cattle. This could result in flukicide residues in milk if animals are improperly treated or if withdrawal periods are not properly observed. The purpose of this review is to summarise the results of studies on depletion of flukicides from milk and the transfer of flukicide residues to dairy products, if present in the milk. As the depletion of flukicide residues from milk of animals treated during lactation was relatively slow, the studies support the view that the dry period (when milk is not being used for human consumption) is the most suitable time for flukicide treatment. Migration of residues to product occurred at different rates, depending on the drug in question. Generally, concentration of flukicides occurred in cheese, butter and skim milk powder. Pasteurisation or heat treatment during spray drying had no impact in reducing residues.