Czech Journal of Animal Science - In Press
Lactoferrin content determined in bovine milk by HPLC and mid-infrared spectrometry - relation to udder health and potential for detection of milk adulterationOriginal Paper
Hana Nejeschlebová, Oto Hanuš, Klára Bartáková, Craig Parsons, Eva Samková, Lenka Vorlová, Gavin Thompson, Lucie Hasoňová, Roman Konečný, Pavlína Navrátilová, Marcela Klimešová
Lactoferrin (LF) is a multifunctional glycoprotein associated with the udder health of dairy cows. The aim of this study was to develop a calibration model for LF quantification using mid-infrared spectrometry (MIR-FT; LF MIR-FT). Ion-pair reversed-phase high-performance liquid chromatography (HPLC; LF HPLC) was employed as the reference method. Two sets of individual milk samples, set A (n = 120) and set B (n = 91), were collected from five dairy farms in the Czech Republic. The milk samples in set A were selected so that approximately two-thirds exhibited a somatic cell count (SCC) above 300 000 cells/ml, which proved effective in ensuring greater LF variability. The final calibration set (set C; n = 205) was formed by merging sets A and B, excluding six outliers. For the developed calibration, a cross-validated coefficient of determination of 0.588 7 and a standard error of cross-validation of 67.33 mg/l were achieved. Correlation analysis indicated that several milk parameters in set C correlated with LF MIR-FT in ways consistent with changes typically observed during mastitis (most notably SCC: r = 0.450; lactose monohydrate: r = –0.364; free fatty acids: r = 0.621 and electrical conductivity: r = 0.442). This suggests that the MIR-FT method may have potential for assessing mammary gland health in dairy cows. Furthermore, we aimed to investigate the feasibility of using LF content in milk as an indicator of milk adulteration by artificially reducing SCC through milk centrifugation. For this purpose, two sets of milk samples (n = 20 and n = 68) were collected, both consisting of normal bulk tank milk and bulk tank milk supplemented with abnormal milk from dairy cows in the Czech Republic. Centrifugation of milk resulted in only minimal changes in both LF HPLC and LF MIR-FT (maximum 3.27%), while SCC decreased by nearly 50%. Therefore, LF could serve as a marker for the detection of artificial SCC reduction in milk by centrifugation. The practical application of the MIR-FT method for LF determination is limited by the achieved validation parameters (R²CV, SECV) and the associated estimated expanded combined uncertainty (114.7 mg/l). The MIR-FT method is therefore more suitable for monitoring relative LF changes in milk than for determining exact LF values (e.g., those associated with cow health status, the course of lactation or milk processing).
Sperm quality improvement of cryopreserved boar semen through colloidal centrifugation gradientOriginal Paper
Francisco Sevilla, Ignacio Araya-Zúñiga, Patricia Cervantes-Acosta, Antonio Hernández-Beltrán, Manuel Barrientos, Belisario Domínguez, Anthony Valverde
Boar semen cryopreservation is limited due to lower sperm cell thermal shock resistance. A colloidal centrifugation gradient is an enhancement to cryopreservation that could improve frozen boar semen quality. Evaluate cryopreserved boar semen quality using a commercial colloidal centrifugation gradient. A total of 15 ejaculates from 5 boars were evaluated across two treatments: a control without colloidal centrifugation and a treatment with commercial colloidal centrifugation. A manual freezing method used two freezing curves in liquid nitrogen. Sperm motility was assessed with Computer-Assisted Semen Analysis, as well as sperm capacitation-like membrane destabilization at 30 min and 150 min post-thaw using Merocyanine 540 (M540) for samples incubated at 37 °C. Spectrophotometry measured lipid peroxidation indirectly by the amount of malondialdehyde; reactive oxygen species production was also determined for sperm samples incubated for 30 min. Gradient centrifugation treatment improved ejaculate sperm motility and membrane destabilization. The proportion of morphologically normal sperm was higher in gradient than control. A total of 74% of spermatozoa retained normal morphology. Lipid peroxidation was lower in the colloidal centrifugation treatment. MDA was lower with gradient (16.4 ± 2.5 vs. 22.3 ± 2.5 µmol/30 × 106 sperm; p < 0.05). Intracellular reactive oxygen species (ROS) and M540‑positivity did not differ significantly between treatments at either time point. The centrifugation process improved quality parameters of frozen boar semen post-thaw.
Effects of Silymarin Supplementation During Late Gestation on Reproductive Performance, Haematological Parameters, Antioxidant Status, and Gut Microbiota in SowsOriginal Paper
Guanglei Cong, Chunxue Liu, Shuangshuang Xia, Junbo Li, Ifen Hung
This study aimed to evaluate the effects of silymarin supplementation during late gestation on reproductive performance, haematological parameters, antioxidant capacity, and gut microbiota composition in sows. Twenty parity-4 crossbred sows (Landrace × Yorkshire) were enrolled and randomly allocated in parity blocks to either a control group (CG; n = 10, basal diet) or a silymarin-supplemented group (SIL; n = 10, basal diet + 200 mg/kg silymarin). The experimental period extended from day 85 of gestation to the completion of farrowing. The results demonstrated that dietary silymarin significantly reduced the number of stillbirths (P < 0.05), without exerting a significant effect on the total number and proportion of live-born piglets (P > 0.05). No notable differences were observed in haematological parameters between the two groups (P > 0.05). However, catalase (CAT) activity and total antioxidant capacity (T-AOC) were significantly elevated in the silymarin group (P < 0.05), and superoxide dismutase (SOD) showed a tendency to increase (P = 0.078). High-throughput 16S rRNA sequencing revealed 1,671 unique feature sequences in the silymarin group and 1,073 in the control group, with 1,600 sequences shared by both groups the two groups. A trend towards increased dominance was observed in the silymarin group (P = 0.082), while both the Shannon and Simpson indices tended to decline (P = 0.087; P = 0.082), suggesting a possible reduction in microbial diversity. Principal coordinate analysis (PCoA) of β-diversity revealed significant structural differences in gut microbiota between the two groups. SIMPER analysis identified Terrisporobacter as the principal genus contributing to these differences. In conclusion, silymarin supplementation during late gestation may enhance reproductive outcomes in sows, potentially through modulation of gut microbial composition and enhancement of systemic antioxidant status.