The aim of this study is to assess the effects of parity number on sow reproductive performance and the chemical and immunological composition of colostrum and immunoglobin concentrations in the sera of the sows. Colostrum samples were collected at 0, 6 and 24 h after the births of the first piglets from 56 sows with different numbers of parturitions (ranging 1–6). The piglets born alive to primiparous sows had lower birth weights (p < 0.05) than piglets from second and fourth parturition sows. The colostrum composition was influenced (p < 0.05) by parity number: primiparous sows had higher concentrations of dry matter, fat, lactose and non-fat-solids. No parity-dependent differences were found concerning total protein amount. Colostrum composition was drastically affected (p < 0.001) by sampling time—the highest concentrations of dry matter and protein and lowest concentrations of fat and lactose were found immediately after parturition (0 h). The study revealed no effect of parity (p ≥ 0.05) on the concentrations of immunoglobulins in colostrum. The immunoglobulin with the highest level in sow serum at day 110 of gestation was IgG, while IgA showed the lowest values and greater variability with respect to parity from an immunological point of view. Regarding the relationship between serum Ig levels at the end of gestation and colostrum Ig, serum IgG showed a strong correlation with colostrum IgG and IgM, while colostrum IgG was strongly related with colostrum IgM, but not with IgA. IgA did not correlate with any other immunoglobulin. The different behaviors of the immunoglobins in colostrum were probably due to IgG coming almost exclusively from the sows’ sera, whereas IgA is mainly synthetized by the mammary gland.

The aim of this study was to evaluate whether piglets absorb immunoglobin G (IgG) from goat colostrum and the potential effects of its ingestion on suckling piglets. Thirty-eight piglets with body weights ranging from 1000 to 1700 g were assigned to one of the three experimental treatments: Control group (C), where piglets were allowed to suckle normally, and porcine and goat groups. The piglets from the last two groups were removed from the sows after birth and received an oral 20 mL dose every 3 h of porcine (PC) or goat colostrum (GC), respectively, during first 12 h of life. Then, they were returned to newly farrowing sows to continue suckling until 20 d. The apparent efficiency of absorption (AEA) of IgG at 12 h was calculated as total serum IgG divided by ingested IgG. No diarrhea or symptoms of intolerance were observed at any time. On day 20, body weight and the number of dead piglets were similar in all three treatments (p > 0.05). At 12 h, the concentration of goat IgG in the serum of piglets fed GC was 8.11 mg/mL. AEA was 20.9% for goat IgG and 26.3% for porcine IgG (p > 0.05). Therefore, goat colostrum seems a promising alternative to study new feed supplements or artificial rearing of newborn piglets.

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.

The increasing use of hyperprolific sows has led to greater litter heterogeneity, highlighting the need for effective nutritional support for low-birth-weight piglets. This study explores the potential of using surplus goat transitional milk as a nutritional supplement for piglets, especially for those facing increased survival and developmental challenges during the early life stages. To this end, two experiments were carried out as follows: in the first, goat transitional milk was administered via an oro-esophageal feeding tube to all piglets in the litter; in the second, concentrated transitional milk was administered via an oral dispenser to whole litters composed of low-birth-weight piglets. Performance parameters, mortality, and serum IgG levels were measured. In Experiment 1, supplementation with goat colostrum showed a tendency to improve weight in piglets ≤ 1100 g, with no significant effect on temperature, serum IgG level, or mortality. In Experiment 2, supplementation with goat colostrum did not affect live weight, rectal temperature, or serum IgG levels at 10 and 21 days. However, there was a trend towards lower mortality at 21 days in the supplemented piglets. These results suggest that goat transitional milk may provide context-dependent benefits, with a potentially greater impact on vulnerable piglets in more difficult conditions. Furthermore, its use represents a sustainable strategy to valorize surplus milk from goat farms.

This study compared the whey proteome of sow colostrum (SC) and goat colostrum (GC) using shotgun proteomics combined with protein equalization techniques (CPLL or ProteoMiner™) to enhance the detection of low-abundance proteins. Colostrum samples were pooled from 11 hand-milked sows (20 mL each, collected at 0 h postpartum), while GC samples (2 liters total) were collected from 50 goats during morning milking on day 1 postpartum. A total of 86 low-abundance proteins (<30 kDa) were identified: 26 unique to SC, 32 to GC, and 14 shared. Major whey proteins, including α-S1, α-S2, β-casein, κ-casein, and lactotransferrin (LTF), were present in both colostra. Gene Ontology (GO) enrichment showed that SC proteins were mainly linked to biological regulation (49.04%) and immune response (11.49%), whereas GC proteins were associated with metabolic processes (26.98%) and biological regulation (26.43%), likely reflecting species-specific physiological differences. Protein–protein interaction (PPI) analysis identified highly connected proteins such as LTF, α-lactalbumin, β-casein, Apolipoprotein, and Clusterin in both networks, with additional interactions involving serum albumin in SC. GC displayed unique interactions with Glycam-1, a glycosylated adhesion molecule related to the milk mucin complex, though its immune role remains unclear. These findings provide novel insight into the functional whey proteome of SC and GC, particularly regarding low-abundance proteins, and highlight the value of shotgun proteomics with protein equalization. Surplus goat colostrum emerges as a sustainable heterologous source to enhance piglet survival in hyperprolific systems. The study also underscores the need for parallel gel replicates to minimize technical variability in future proteomic analyses.