Preweaned heifer management on US dairy operations: Part II. Factors associated with colostrum quality and passive transfer status of dairy heifer calves

Abstract

Passive transfer of immunity is essential for the short- and long-term health of dairy calves. The objective of this study was to evaluate factors associated with colostrum quality and passive transfer status of US heifer calves. This study included 104 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,972 Holstein heifer calves from birth to weaning. Multivariable mixed linear regression models were selected using backward elimination model selection after univariate screening to determine which factors were associated with colostrum IgG and serum IgG concentrations. The mean colostrum IgG concentration was 74.4 g/L with 77.4% of colostrum samples having IgG concentrations >50 g/L. The final model for colostrum IgG included colostrum source and a categorized temperature-humidity index value (cTHI) for the month before calving. Mean colostrum IgG concentrations were highest for dams in third and higher lactations (84.7 g/L) and lowest for commercial colostrum replacers (40.3 g/L). Colostrum IgG concentrations were highest for cTHI ≥70 (72.6 g/L) and lowest for cTHI <40 (64.2 g/L). The mean serum IgG concentration was 21.6 g/L, with 73.3% of calves having serum IgG concentrations >15 g/L. The final model for serum IgG concentration included region, heat treatment of colostrum, colostrum source, timing to first feeding, volume of colostrum fed in the first 24 h, age of the calf at blood sampling, and colostrum IgG concentration. Mean serum IgG concentrations were highest for calves that received colostrum from first-lactation dams (25.7 g/L) and lowest for calves fed commercial colostrum replacer (16.6 g/L). Serum IgG concentrations were higher for calves fed heat-treated colostrum (24.4 g/L) than for calves fed untreated colostrum (20.5 g/L). Serum IgG concentration was positively associated with the volume of colostrum fed in the first 24 h and colostrum IgG concentration, and negatively associated with the number of hours from birth to colostrum feeding and age (days) at blood collection. Dairy producers should be encouraged to measure the quality of colostrum before administering it to calves and to measure serum IgG or a proxy such as serum total protein or Brix to evaluate passive immunity and colostrum management programs.

Colostrum Management for Dairy Calves

“…A total of 77.4% of samples had colostrum IgG level greater than 50 g/L. 46 Factors affecting colostrum quality and yield are reviewed next and methods for testing colostrum quality are discussed.…”

“…Most, but not all, studies report a tendency for older cows to produce higher-quality colostrum, presumably /because of older animals having had a longer period of exposure to farm-specific pathogens. 46,49,50 In a study by Shivley and colleagues, 46 colostrum from first and second lactation cows had similar colostrum quality (73.2 and 71.7 g/L of IgG), whereas colostrum from third lactation and older cows was of higher quality (83.3 g/L IgG). Producers should test and record the quality of all colostrum fed.…”

“…Although some studies have reported that exposure to high ambient temperatures during late pregnancy is associated with poorer colostrum composition, including lower mean concentrations of colostral IgG and IgA, 49,58 others have reported the opposite. 46 It has been suggested that any negative effects of heat stress on colostrum quality might be associated with reduced dry matter intake or reduced mammary blood flow resulting in impaired transfer of IgG and nutrients to the udder. 58 Season may also have an impact on colostrum yield, although this is less well described.…”

Invited Review: Nutritional regulation of gut function in dairy calves: From colostrum to weaning

“…This percentage has decreased from a study conducted by Beam et al (2009), which reported 19.1% of heifer calves had FPT, as well as from 1991 to 1992, in which over 40% of calves had FPT (USDA, 1993). It appears that this number may be decreasing over time; however, it is important to note that the most recent large-scale studies (Beam et al, 2009;Shivley et al, 2018) were conducted either as a convenience study, due to less farms participating in the study than anticipated , or included only healthy heifer calves (Beam et al, 2009), whereas the USDA (1993) did not distinguish between healthy and unhealthy calves before blood collection. Therefore, although the most current rate of FPT is reported as 12.1%, it is likely that the true rate of FPT on North American dairy farms could be greater.…”

“…At approximately 24 h after birth (Stott et al, 1979a), "gut closure" occurs, which is defined as "the cessation of absorption of macromolecules from the gut into blood in neonates" (Lecce and Morgan, 1962). Shivley et al (2018) found that serum IgG concentrations decreased by 0.32 mg/mL every hour following birth after colostrum feeding, and it is widely accepted that the absorption of IgG decreases in a linear trend as calves age (Stott et al, 1979a;Bush and Staley, 1980;Matte et al, 1982). However, Fischer et al (2018c) recently demonstrated a nonlinear trend in the absorption of IgG, with calves fed immediately after birth (0 h) having greater serum IgG concentrations compared with calves fed at 6 and 12 h after birth, which did not differ.…”