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In this review authors address colostrum proteins implications in different domestic ruminant species. The colostrogenesis process and how different factors, such as litter size or nutrition during gestation can alter the different components concentrations in colostrum are also reviewed. The different colostrum fractions will be described, focusing on high and low abundant proteins. This review describes the major function of such proteins and their role on the passive immune transfer and nutrition in the newborn animal. It will be also performed a comprehensive review on different techniques and commercial kits available for high abundant protein depletion in colostrum. We will finally focus on how proteomics has been used to address this issue and how it can contribute to the major questions about colostrum associated immunology.

Seasonal weight loss (SWL), caused by poor quality pastures during the dry season, is the major limitation to animal production in the tropics. One of the ways to counter this problem is to breed animals that show tolerance to SWL. The objective of this study was to understand the effect of feed restriction in milk production and live weight (LW) evolution in two goat breeds, with different levels of adaptation to nutritional stress: the Majorera (considered to be tolerant) and the Palmera (considered to be susceptible). A total of ten animals per breed were used. Animals were divided in four groups (two for each breed): a restricted group (restricted diet) and a control group. LW and milk yield parameters were recorded through a trial that lasted 23 days in total. Overall, there were no significant differences between both restricted groups, regarding neither LW nor milk yield reductions (LW reduction 13 % and milk yield reduction of 87 % for both restricted groups). In what concerns control groups, there were no significant differences between breeds, thought there were different increments at the end of the trial for both breeds regarding LW (6 and 4 %, for Majorera and Palmera, respectively) and milk yield (28 and 8 %, respectively for Majorera and Palmera). The lack of statistically significant differences between Palmera and Majorera LW and milk yields in restricted groups may be due to the fact that the controlled trial does not replicate harsh field conditions, in which Majorera would excel, and the stress induced by those differences.

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The overall objective was to compare immunoglobulin G (IgG) concentrations measured by single radial immunodiffusion (sRID) and ELISA-based methods in samples of bovine colostrum and transition milk from contrasting breed types (Limousin × Friesian (n = 10) and Holstein (n = 10)). Jugular blood samples were collected at 48 h post-birth from beef (n = 10) and dairy (n = 10) calves and sera harvested subsequent to colostrum consumption. Absolute colostrum IgG values determined by ELISA showed poor agreement with mean (SD) IgG values measured using sRID, fixed bias (sRID -ELISA) was 31.89 (±9.84) mg/mL; having wide limits of agreement (12.61-51.17) and a low concordance coefficient (0.26). The agreement between ELISA and sRID when measuring serum IgG was greater than that of colostrum, fixed bias (sRID -ELISA) was 12.36 (±6.60) mg/mL; having narrower limits of agreement (−0.58 to 25.30) and serum IgG concentrations had a greater concordance coefficient (0.44) between samples. Calf sera IgG measured using the indirect zinc sulphate turbidity test showed a strong correlation with the sRID and ELISA methods (P < .001), R 2 = 0.78 and R 2 = 0.77 respectively. Overall, the ELISA and sRID methodologies had a strong positive association with almost a twofold (1.8) difference between values; therefore, they provide diverse absolute values of IgG concentration. ARTICLE HISTORY