Jill V Hagey

University of California, Davis | UCD · Department of Animal Science

The rumen is a complex ecosystem that plays a critical role in our efforts to improve feed efficiency of cattle and reduce their environmental impacts. Sequencing of the 16S rRNA gene provides a powerful tool to survey the bacterial and some archaeal. Oral stomach tubing a cow to collect a rumen sample is a rapid, cost-effective alternative to rume...

Improved sequencing and analytical techniques allow for better resolution of microbial communities; however, the agriculture field lacks an updated analysis surveying the fecal microbial populations of dairy cattle in California. This study is a large-scale survey to determine the composition of the bacterial community present in the feces of lacta...

Malnutrition remains a leading contributor to the morbidity and mortality of children under the age of five worldwide. However, the underlying mechanisms are not well understood necessitating an appropriate animal model to answer fundamental questions and conduct translational research into optimal interventions. One potential intervention is milk...

Colostral administration practices on dairy farms have significantly improved over the last 15–20 years resulting in prevalence of calves ingesting insufficient colostrum decreasing from 35–40% to 19%. Despite these improvements, the serum immunoglobulin G (IgG) concentration of ≥1000 g/dl and serum total protein (TP) concentrations of ≥5·2 g/dl ar...

The cotyledonary placenta allows minimal transfer of immunoglobulins from the cow to the fetus during pregnancy. Consequently calves are born hypogammaglobulinemic, thus making it essential to ingest and absorb colostral immunoglobulins to acquire passive immunity. Therefore, the half-life of maternally derived colostral immunoglobulin G (IgG) in d...

Intravenous plasma administration has been recommended in healthy or sick calves with failure of passive immunity. IV administered plasma-derived immunoglobulin G (IgG) undergoes increased catabolism as reflected by a rapid decrease in serum IgG concentration with an increase in fecal IgG concentrations within 48 h. Thirty newborn Jersey calves. Fi...

Background Estimation of the quantity of colostral IgG or serum IgG absorbed following ingestion of colostrum by calves is essential for monitoring the effectiveness of colostrum feeding practices on dairy farms. Milk total solids concentrations determination is a critical part of quality assessment of nonsaleable whole milk prior to feeding to cal...

In calves, passive immunity of immunoglobulins can be acquired through ingestion of colostrum or colostrum replacers. Plasma can been used to supplement immunoglobulins in healthy or sick calves. Serum half-life of colostral derived immuglobulin G (IgG) is estimated to be 20 days. Half-life of IgG is important in determining response to antigens an...

To compare the apparent efficiency of absorption of IgG and failure of passive transfer of immunity rates between calves fed colostrum by nipple bottle (NB) and oroesophageal tubing (OET). Randomized controlled study. 26 Holstein bull calves (age, 4 to 8 hours). Calves were randomly assigned to receive colostrum by either NB or OET. Pooled colostru...