Suckled calves had significantly higher serum IgG 1 concentrationsthan mart purchased dairy calves.The marked differences in immunoglobulin levels between suckledcalves and dairy calves suggest that these calves received eitherinsufficient quality or quantity of colostral immunoglobulins.Factors affecting calf serum Ig concentrations are, Ig concentrationin colostrum, colostrum intake, Ig mass, calf age at first feeding,nutrition of the dam, method of ingestion, presence of the dam, ageof the dam and the calf.When suckled calves were fed a similar volume of colostrumrelative to birth weight (40 ml/kg) and at the same time intervalpost birth, there was no significant difference across the threesuckler herd progeny for IgG1, IgA and IgM and total Ig serum levelsat 28 and 56 days of age. However, serum IgG2 levels were significantlylower in the Limousin x beef breed when compared with theCharolais x beef breed suckled calves at 28 days of age.Healthy calves had higher serum immunoglobulins (IgG1) thancalves treated for respiratory disease, enteric disease or for bothrespiratory disease and enteric disease.It is well recognised that immunoglobulins are absorbed fromthe intestine for only a short period post birth and that efficiencyof absorption is dependent on ensuring that the calf receives adequatecolostrum in the immediate post-partum period.Low serum IgG1 concentrations are attributable to failures toobtain adequate colostral immunoglobulins in the period immediatelyfollowing birth.The mean IgA and IgM serum levels of suckled calves in the presentstudy were only slightly higher than dairy calves while IgG1serum levels were almost approximately twice as high.Feeding colostrum high in Ig results in higher calf serum Ig concentrationsat 48h.The low serum Ig levels reported in the present study suggestthat dairy calves failed to obtain adequate transfer of colostralimmunoglobulins.Calves with a lower immune status are more susceptible toneonatal infection and thus the importance of colostrum in theimmediate post partum period cannot be overemphasised. Thus,the identification of calves with low levels of immunity might stimulate calf producers to ensure that calves receive adequate levels of colostralimmunoglobulins.The implications of the present findings are that compared with suckledcalves, dairy calves are not receiving 1). adequate quantity of colostrum 2).adequate quality of colostrum. 3). Colostrum soon enough post birth 4).or a combination of all of the previous factors.Rearing calves outdoors using calf jackets had no beneficial effect on calfperformance. The incidence of respiratory disease was higher in calvesreared indoor when compared with calves reared outdoor with and withoutjackets. There was an increased incidence of diarrhoea in calves rearedoutdoors irrespective of calf jacket.Lymphocytes from calves with respiratory disease manifest an impairedcapability to blast in vitro.Chromium (Cr) supplementation (250 mg/kg dry matter intake) enhancedthe blastogenic response in healthy calves, while, calves with respiratoryhad impaired blastogenic responses.Supplementation with organic Cr (250 mg/kg dry matter intake) for 63days had no major effect on physiological parameters and had select effectson haematological parameters, namely, the % monocytes. The % monocyteswere significantly higher in the standard commercial milk replacer (CMR)(Skim) Cr supplemented calves when compared with the whey based(CMR) + Soya Brand B or whey based CMR + Soya Brand C or whey basedenzyme processed soya Brand C + Cr treatment groups.
AGRIP End of Project Reports
Teagasc End-of-Project Reports