Serum lactoferrin concentrations in colostrum-fed calves

A Scoping Review of On-Farm Colostrum Management Practices for Optimal Transfer of Immunity in Dairy Calves

Newborn calves are agammaglobulinemic and rely for their first immune protection almost completely on the transfer of immune constituents via colostrum. Inadequate colostrum management practices such as on-farm colostrum storage practices and colostrum feeding methods could affect immune components in colostrum and subsequently immune status of the newborn calf. We conducted a scoping review to identify all literature on the interactions between several colostrum management factors and immunological colostrum quality and passive transfer of immunity. Three major stages were defined: milking methods, colostrum treatment and storage, and administration procedures. Separate CAB Abstracts searches were performed for each of the subjects of interest. The search process was completed on November 9, 2020. Colostrum should be milked as soon as possible, as IgG concentration diminishes over time, probably due to dilution. To minimize bacterial contamination, it is advised to pasteurize colostrum in small batches at maximal 60°C for 30 or 60 min. Freeze/thawing of colostrum does not or only slightly affect IgG concentrations, as long as thawing is done au bain-marie and temperature does not exceed 40°C. In on-farm situations, it is difficult to determine the volume that should be fed as the variables contributing to the absorption of IgG by the newborn calf are many and include the quality of the colostrum, the bacterial contamination, the time interval between birth and first moment of feeding and the weight of the calf. Despite all knowledge regarding optimal colostrum management strategies, it remains challenging to predict the effects of certain colostrum management choices in field conditions. Therefore, we recommend measuring the colostral quality, weighing the newborn calf, adjusting the feeding volume accordingly to ensure optimal colostrum intake for each calf.

Crosstalk between coagulation and inflammation in mastitis and metritis in dairy cows

Coagulation and inflammation are closely related as part of the mechanisms of host defence during a severe infection. The aim of this study was to investigate the relation between thrombin as a factor in both the coagulative and inflammatory processes and neutrophil secretory function on the basis of lactoferrin (LF), elastase and myeloperoxidase release in the course of mastitis and metritis in cows. Thrombin generation was measured on the basis of hydrolysis of SAR-PRO-ARG-pNA and lactoferrin concentration was estimated by an ELISA method. The greatest thrombin generation was observed in the metritis group (1.18 +/- 0.62 IU). The level of LF was the highest in the group of cows with mastitis (0.74 +/- 0.55 mg/ml) in the first phase of the disease. In the second phase of the diseases the level of serum LF in cows with mastitis diminished to the value of 0.41 +/- 0.16 mg/ml, whereas in cows with metritis the level of LF increased to 0.51 +/- 0.17 mg/ml. This study reveals that the excessive production of thrombin not only causes hypercoagulatory disorders but also exaggerates neutrophil function by the release of some enzymes which may play a destructive role during disseminated intravascular coagulation (DIC). These enzymes also inhibit anticoagulative systems, thus potentially worsening the course of the disease.

Effect of passive transfer status on preweaning growth performance in dairy lambs

OBJECTIVE

To evaluate the effect of passive transfer status, determined by measuring serum IgG concentration 24 hours after parturition, on preweaning growth performance in dairy lambs.

DESIGN

Prospective observational study.

ANIMALS

20 healthy Sardinian dairy lambs.

PROCEDURES

Serum IgG concentration was measured 24 hours after birth. Body weight was measured at birth and at the time of weaning 28 days (ie, 27 to 29 days) after birth. Mean daily gain from birth to day 28 and day 28 weight were used as measures of preweaning growth performance. Regression analysis was used to evaluate associations between serum IgG concentration 24 hours after birth and measures of preweaning growth performance.

RESULTS

Mean +/- SD serum IgG concentration 24 hours after birth was 24.6 +/- 17.5 mg/mL. Mean body weights at birth and weaning were 2,696 +/- 937 g and 9,253 +/- 2,116 g, respectively, and mean daily gain was 234 +/- 63 g/d. No significant association was detected between serum IgG concentration 24 hours after birth and birth weight. However, serum IgG concentration 24 hours after birth was significantly associated with mean daily gain (R(2) = 0.25). Each 1 mg/mL increase in serum IgG concentration 24 hours after birth was associated with a 1.8 g/d increase in mean daily gain and a 60.8-g increase in day 28 weight.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that passive transfer status, determined as serum IgG concentration 24 hours after birth, was a significant source of variation in preweaning growth performance in dairy lambs.

Safety determination for the use of bovine milk-derived lactoferrin as a component of an antimicrobial beef carcass spray

Bovine milk-derived lactoferrin (BMDL), an iron-binding glycoprotein, is known to be an effective natural antimicrobial. It is used as a spray, applied electrostatically, to raw beef carcasses to detach bacteria adhering to the surface in order to reduce microbial contamination. The use of BMDL as a component (at not more than 2% by weight) of an antimicrobial spray was determined Generally Recognized As Safe (GRAS) (GRN 67) for three proposed uses (i.e., beef carcasses, subprimals, and finished cuts), provided that the ingredient statement of food products that contain milk-derived lactoferrin identifies the source of the protein. The use of BMDL spray on only beef carcasses (not subprimals or finished cuts) at a level not to exceed 0.20 ml of formulation per kg of beef was determined safe without the requirement of labeling of food products so treated. The two key components of the assessment are: (1) a determination that exogenous lactoferrin exposure (resulting from its application to beef carcasses) is in the range of existing background exposures of lactoferrin as a result of lactoferrin found naturally in beef, and (2) a determination that this potentially small incremental increase in lactoferrin is safe (i.e., there is no reasonable expectation that BMDL will become an allergen under the conditions of its intended use).