Major management factors associated with the variation in reproductive performance of Irish dairy herds

End of project reportThe results highlight the importance of BCS in achieving good reproductive performance. The likelihood of reproductive success was best predicted by BCS around the time of breeding and, for cows calving in good BCS (3.0 or greater) the level of BCS loss between calving and first service. A low BCS pre-calving (3.5) results in excessive BCS loss (>0.5) post-calving. On the basis of these findings a pre-calving BCS of no greater than 3.25 is a sensible target for pasture-based spring calving systems in Ireland. It is necessary to maintain BCS at 2.75 or greater during the breeding season, and loss of body condition between calving and first service should be restricted to 0.5 BCS units.National Development Plan (NDP

Epidemiology and economic impact of Johne's disease in Irish dairy herds

End of project reportThis project addressed two aspects of an emerging infectious disease of Irish cattle; the epidemiology and the economic impacts of Johne’s disease (paratuberculosis). Though this disease has been present in Irish cattle herds for decades, only since the introduction of the Single European Market in 1992 has it become more widespread. In addition to this change in the epidemiology of the disease in Irish cattle, there is increasing evidence that the causative organism, Mycobacterium avium subsp. paratuberculosis (MAP) may be implicated in a human illness, Crohn’s disease, though proof of a zoonotic link is currently disputed (Tremblay, 2004). Against this background a collaborative research project was set up by Teagasc and funded by Irish dairy farmers

Temporal trends in reproductive performance in Irish dairy herds and associated risk factors

peer-reviewedIrish dairy herd fertility has been declining since the 1980s. The extent, nature and causes of this decline in fertility and the current status of Irish dairy herd fertility were described. An increase in calving interval of approximately one day per year has been recorded. The principal components of this trend have been an increased incidence of postpartum endocrinopathies, reduced expression of oestrus and a fall in conception rate. Both submission rate and calving-to-service interval have increased slightly over time. Significant risk factors associated with these trends have been strain substitution within the Holstein-Friesian breed and single trait selection for milk production. Critically, these changes have been reflected in loss of body condition. Contributory factors included increased herd size and possibly increased use of DIYAI. The most recent Irish study showed that 48% of cows conceived to first service and 14% of cows were not pregnant at the end of the industry-average 15-week spring breeding season. However, the top quartile of herds achieved a first-service conception rate of 59%, illustrating the wide variation between herds. These phenotypic trends were attributed to both genetic and environmental factors and their interactions. Recent Irish dairy herd fertility performance falls short of the targets set for seasonal compact calving

Systems of Winter Milk Production based on all Autumn Calving Cows

End of Project ReportA supply of winter milk is needed by certain milk processors for the production of high value dairy products with a short shelf life to balance the high level of commodity based products which are mainly manufactured from seasonal milk produced from spring calving herds. Winter milk is generally produced by suppliers with split calving herds. A proportion of the cows (30-50%) calve in Autumn (September-December) to supply winter milk for which they receive a winter bonus for a contracted supply for the months of October to February. The remainder of the herd calve in Spring (Feb-April) and produce milk mainly off grass for which no bonus is paid. This system evens out the supply of milk throughout the year but complicates management, as it involves running two herds on the farm, with two calving seasons, two breeding seasons and two sets of replacement heifers to be reared. Also there is no break from milking. A system of winter milk production based on calving all of the cows in Autumn would be simpler, as it would involve only one herd, with a break from milking in late Summer and would appeal to many winter milk producers. In this study the feasibility of operating an all Autumn calving herd was examined, in terms of management, calving, winter feeding, reproduction and summer grazing. The herd was located in the Ballyderown farm attached to the Moorepark Research Centre. Alternative winter feeding systems were put in place over a three year period to compare the feed requirements and milk production of each system. A control system based on grass silage as the sole forage was compared with one where grass silage was supplemented with extended grazing of grass in late Autumn and early Spring or with a system based on a mixed forage diet based on grass silage, maize silage, brewers grains or a brewers grains/beet pulp mix. Grass silage and maize silage was produced within each system and the cows on each system were grazed separately within their own farmlets. The overall stocking rate for each system was 2.7 cows/ha using 350 kg N fertiliser/ha in addition to cattle slurry. Cows were dried off in mid-late July and were grazed tightly until calving down. The calving season extended from early September to early December. Most cows calved down outdoors at pasture or in a calving paddock without assistance. Cows were housed from early November to late March and were allocated to their respective diets in batches according to milk yield, lactation number and calving date. The cows given access to winter grass were given a daily allocation of grass (6-8 kg DM/cow) and grazed between morning and evening milking

Perinatal immuno/inflammatory responses in the presence or absence of bovine fetal infection

peer-reviewedBackground It is known that the bovine fetus can mount an immune and inflammatory reaction to infection, but it is not known whether there is a contemporaneous maternal response. Nor is it known whether the response of calves which die perinatally, with or without infection, differs from that of live perinates. Hence, the objective of this study was to determine if acute phase reactant and immunoglobulin concentrations differed between calves (and their dams) in three groups: live calves (CC; n = 21) and dead calves with (PM INF+; n = 22) or without (PM INF-; n = 89) in utero infection. In calf plasma, serum amyloid A, haptoglobin, immunoglobulins M, G1 and G2 and interleukin-6 were measured. In dam serum, SAA and Hp was measured and in amniotic and abomasal fluid, IL-6 was measured. Results Live calves had higher plasma concentrations of SAA and IL-6 than dead calves with (PM INF+) or without (PM INF-) in utero infection. Calves in the PM INF-, but not PM INF+ group, had higher Hp concentrations than calves in the CC group. Calves in the PM INF+ group had higher IgG1 concentrations than calves in the PM INF- and CC groups. Except for higher IgG1 and IgG2 concentrations, biomarker values did not differ significantly between dead calves with or without in utero infection. Live calves had higher IL-6 concentrations in abomasal fluid compared to PM INF- calves. There were no significant differences in blood biomarker concentrations between dams of the three groups of calves. Amniotic fluid IL-6 concentrations were higher from the dams of control calves than the dams of uninfected calves. Conclusions Differences in biomarkers (higher Hp and IgG1; lower SAA and IL-6) between perinatal mortalities and live perinates probably reflect differences between these two groups in age at sampling (SAA and IL-6) and in utero infection (IgG1). Out of the six analytes measured in calves, only IgG1 and IgG2 were biomarkers of (chronic) in utero infection

Investigation of bovine abortion and stillbirth/perinatal mortality - similar diagnostic challenges, different approaches

peer-reviewedAbstract This pracademic paper reviews current bovine foetopathy (abortion and stillbirth) case definitions, reporting and triage, and causes and time-of-death and proposes veterinary practitioner-focused investigative standard operating procedures (SOPs). Issues of under- and over-triage and intra-institutional SOP harmonisation are also discussed. It is proposed that an ‘observable abortion’ (120–260 days of gestation) is a more practitioner-friendly definition of abortion for reporting and benchmarking purposes and that the term ‘peristillbirth’ can replace stillbirth and perinatal mortality. Diagnosis of bovine foetopathy involves an investigative triad of the farmer, veterinary practitioner and the veterinary diagnostic laboratory. However, the poor sensitivity of abortion reporting undermines the value of currently adopted scanning/passive surveillance; parallel active surveillance/sentinel herd models should also be employed. The approach to abortion investigation differs from that of peristillbirth. The former should include collecting a herd and case history, examination and sampling of dam and cohorts and sampling of the foetus and placenta. A sample selection decision tree is provided to assist test selection. In peristillbirths, non-infectious and periparturient causes-of-death are more important hence the anamnesis must focus on peristillbirth risk factors and calving management. The foetopsy, while including the sampling menu appropriate to aborted foetuses, must also include a detailed internal and external examination of the carcass for lesions indicative of periparturient causes-of-death. In addition, for aborted foetuses the time-of-death is not important as the foetus is generally not viable; however, for the peristillbirth the time-of-death is critical as it provides useful information for the farmer to address modifiable risk factors and to alter their perinatal management. Reporting of the ultimate cause-of-death is more useful to prevent future abortions and peristillbirths though the proximate cause-of-death is often reported in the absence of a complete clinical anamnesis. Finally, the common reasons for diagnosis not reached (DNR) and the limitations of current investigative approaches are discussed

Ver la ceguera

opinionEl síndrome de la ceguera de granja afecta tanto a ganaderos como a veterinarios y es necesario conocer sus causas para poder atajarlo

Managing the Calf at Calving Time

peer-reviewedPerinatal mortality rates are increasing internationally, particularly in Holstein-Friesian primiparae. The prevalence of perinatal mortality in US dairy herds is currently 8%. This article outlines our current knowledge of bovine perinatal pathophysiology and presents practical guidelines on management of the calf at calving time. Biophysical profiling of the newborn calf, without sophisticated equipment, is the first step in diagnosing at-risk perinates. Resuscitative techniques adaptable for both the producer and the veterinarian are detailed. In addition, management of prolonged recumbence, hypothermia, failure to suck, umbilical antisepsis and calf movement after calving are discussed. Knowledge gaps constraining future progress towards better newborn calf management are highlighted. Finally, current topics in perinatal mortality are presented

Labour efficiency on-farm

End of project reportImprovements in milking efficiency have a greater influence than any other aspect of the dairy farmers work on overall farm labour inputs (Whipp, 1992). In order to facilitate the examination of milking process labour inputs, the milking process may be divided into the following three components: herding pre and post milking (transfer of cows to and from the milking parlour); milking (milking tasks / work routines within the parlour); and washing (washing of milking machine and yard). Meanwhile, within milking specifically, the number of cows milked per operator per hour is the best measure of both the performance of the operator and the milking installation (Clough, 1978). This is affected by the following three factors: the milking times of the cows, the number and arrangement of the milking units, and the operator’s work routine (Whipp, 1992). The addition of extra milking units will only increase milking performance if the operator has idle time during milking (Hansen, 1999)

Implementing biosecurity measures on dairy farms in Ireland

peer-reviewedDairy farms in Ireland are expanding in preparation for a new era of unrestricted milk production with the elimination of the European Union (EU) production quotas in 2015. Countries experiencing a changing agricultural demographic, including farm expansion, can benefit from documenting the implementation of on-farm biosecurity. The objectives of this study were to document and describe influences on biosecurity practices and related opinions on dairy farms. A representative response rate of 64% was achieved to a nationwide telesurvey of farmers. A 20% discrepancy was found between self-declared and truly ‘closed’ herds indicating a lack of understanding of the closed herd concept. Although >72% of farmers surveyed considered biosecurity to be important, 53% stated that a lack of information might prevent them from improving their biosecurity. Logistic regression highlighted regional, age, and farm-size related differences in biosecurity practices and opinions towards its implementation. Farmers in the most dairy cattle dense region were three times more likely to quarantine purchased stock than were their equivalents in regions where dairy production was less intense (P = 0.012). Younger farmers in general were over twice as likely as middle-aged farmers to implement biosecurity guidelines (P = 0.026). The owners of large enterprises were almost five times more likely to join a voluntary animal health scheme (P = 0.003), and were over three times more likely to pay a premium price for health accredited animals (P = 0.02) than were those farming small holdings. The baseline data recorded in this survey will form the basis for more detailed sociological and demographic research which will facilitate the targeting of future training of the farming community in biosecurity