The Effect of the Season on the Time Dependent Changes in Colostrum Lactoferrin Level in Murciano–Granadina Goats in Intensive System Farming.

Simple Summary: This study analyzed changes in the lactoferrin content of Murciano–Granadina goat colostrum in the first 96 h postpartum as a function of parity season. In addition, we evaluated production and composition (chemical and immunological), and the usefulness of a Brix refractometer for estimating the IgG content of colostrum. Lactoferrin is a protein present in colostrum that has antimicrobial properties, and its colostrum content was heavily affected by time since delivery, as was that of the other chemical and immunological components, except fat. The season influenced milk yield and the contents of lactoferrin, immunoglobulin G, fat, protein, and somatic cells. Lactoferrin contents were significantly lower in the winter season. The quality of goat colostrum estimated using the Brix refractometer vs. ELISA method evidenced a strong correlation. Our results confirm the critical role of colostrum feeding within the first postpartum day to the neonates, attributed to its superior quality, particularly for its contents in bioactive proteins, such as lactoferrin and immunoglobulin. Additionally, we substantiate the efficacy and cost-effectiveness of the Brix method as a rapid assay for evaluating colostrum quality, thus validating its practical utility. The aim of this research was to evaluate the effects of postpartum day and parity season on the lactoferrin (LF), immunoglobulin G (IgG), and chemical composition of Murciano–Granadina goat colostrum during the first 96 h after kidding, and the use of the Brix refractometer to estimate IgG content. A herd of 3500 intensively managed Murciano–Granadina dairy goats (45–50 kg body weight) was used. Colostrum samples were collected from days 1 to 4 postpartum in the winter, spring, summer, and autumn. The colostrum composition was assessed using an automated infrared method; the LF and IgG concentrations were measured using an ELISA, and for the Brix percentage, we used a digital refractometer. Colostrum taken on the first postpartum day showed the highest concentrations of LF, IgG, proteins and non-fat solids (NFSs). As the postpartum days progressed, a rapid decrease in the LF, IgG, protein, and NFS contents and the Brix value was observed. In contrast, the lactose content increased steadily until the fourth postpartum day (p < 0.001). The season influenced milk yield, LF, IgG, protein, fat, and somatic cell content (p < 0.05). LF contents were significantly higher in the spring season, IgG contents were higher in autumn colostrum, and fat components were higher in the winter season. The colostrum Brix value showed a positive correlation with the ELISA colostrum LF (r = 0.716, p < 0.001) and IgG (r = 0.894, p < 0.001) determination; a 20 mg IgG/mL colostrum concentration corresponded to 18 °Brix. Our results corroborate the importance of feeding colostrum to newborns on the first day after birth, not only because of its high level of IgG but also because of its greater presence of the other bioactive protein compounds such as lactoferrin. [ABSTRACT FROM AUTHOR]