A preliminary study on the use of jenny colostrum to improve quality in extenders for freezing donkey semen

Peptidome profiling of human, bovine, and donkey colostrum through label-free quantitative analysis reveals proteolysis of milk proteins

Proteins and peptides play vital roles in different biological processes in vivo. As a dynamic hydrolysis system, milk is rich in proteins and proteases and provides a constant supply of endogenous bioactive peptides to newborn mammals. Previous studies have primarily focused on researching bioactive peptides by adding exogenous enzymes to milk samples. However, such an approach overlooks the significance of endogenous peptides and parent proteins that naturally exist in milk. Herein, we analyzed and compared parent proteins and their releasing peptides in human colostrum (HC), bovine colostrum (BC), and donkey colostrum (DC). The predominant proteins and hydrolyzed peptides in the three types of milk were identified. Among them, peptides were found to possess common bioactivities, including ACE inhibitory, antioxidant, antibacterial and immunomodulatory properties in HC, BC, and DC. Furthermore, the biological functions of these parent proteins were clarified using bioinformatics. These insights offer a novel perspective on natural bioactive peptides and the potential utilization of specific parent proteins and peptides to develop infant formulae derived from diverse milk sources.

Advances in Cryopreservatives: Exploring Safer Alternatives

Cryopreservation of cells, tissues, and organs is widely used in the biomedical and research world. There are different cryopreservatives that are used for this process; however, many of them, such as DMSO, are used despite the problems they present, mainly due to the toxicity it presents to certain types of samples. The aim of this Review is to highlight the different types of substances used in the cryopreservation process. It has been shown that some of these substances are well-known, as in the case of the families of alcohols, sugars, sulfoxides, etc. However, in recent years, other compounds have appeared, such as ionic liquids, deep eutectic solvents, or certain polymers, which open the door to new cryopreservation methods and are also less toxic to frozen samples.

Cholesterol Loaded Cyclodextrin Supplementation Enhances the Cholesterol-to-Phospholipid Ratio and Diminishes Oxidative Stress in Jack Spermatozoa During Cryopreservation

The present study was conducted with the hypothesis that addition of cholesterol to the extender would stabilize the sperm membranes by increasing the cholesterol-to-phospholipid (C:P) ratio and would result in an improved post-thaw semen quality and reduce oxidative stress in the jack (Martina franca) semen. Forty-eight ejaculates from six jacks were collected and analyzed for the present study. The freshly collected semen sample of each jack stallion was divided into five equal fractions after addition of the primary extender without cholesterol-loaded cyclodextrin (CLC) (C) and with 1, 1.5, 2, and 3 mg/mL CLC to obtain 120 × 10⁶ sperm/mL spermatozoa concentration. The semen was cryopreserved using customized freezing protocols. Evaluation of seminal parameters, the C:P ratio, and the oxidative status of jack spermatozoa was analyzed at all stages of cryopreservation. The oxidative status in the jack semen was evaluated by measuring malondialdehyde, glutathione and total antioxidant capacity levels. The results indicated that the mean percent values for various seminal quality parameters and the oxidative parameters were found to be significantly higher (P < .05) in CLC-treated groups with the highest values for 2 mg of CLC/120 × 10⁶ spermatozoa. In conclusion, the present study revealed that the supplementation of CLC before cryopreservation has significantly reduced the oxidative stress and also increased the C:P ratio during semen cryopreservation process. Furthermore, a reduction in lipid peroxidation levels, reduced damage to the sperm plasma and acrosome membranes and improvement in the post-thaw sperm integrity as well as stability were recorded.

Evaluation of jennies' colostrum: IgG concentrations and absorption in the donkey foals. A preliminary study

Immunoglobulin type G (IgG) concentration both in jennies' colostrum and in serum of donkey foals are mostly unknown in the first 24 h after delivery. The aims of the present study were to evaluate the IgG concentrations of colostrum during the first 24 h of lactation of Amiata jennies, the absorption of colostrum and the weekly body weight gain of the donkey foals. IgG concentrations were assessed in the jennies' colostrum and in the serum of donkey foals. Colostrum was collected in 9 jennies ready after delivery, and at 6, 12, 24 h after foaling from both halves. Serum was collected at the same sampling times from 9 donkey foals. Donkey foals were weighted at birth and then weekly until the 28th days of life. Temporal changes of IgG concentrations in dam's colostrum and in donkey foal serum were analyzed by a linear regression model and a general linear model, respectively. Results showed that colostrum IgG concentration were similar between the left and the right half. Colostrum IgG concentrations decreased continuously throughout the time in all jennies by 0.0244 Log10 mg/mL per hour. Serum IgG concentrations in donkey foals at birth was significantly lower compared to other times. No correlation was found between the colostrum IgG concentrations and the average weekly body weight gain of the donkey foal. The pattern of colostrum IgG levels in jennies and serum IgG concentration in donkey foals seem to be similar to what reported for equine. However, the donkey foals seem to be less agammaglobulinemic at birth compared to the horse foal. The pattern and both serum and colostrum concentrations evaluated in the Amiata donkeys were slightly different from results reported in other donkey breeds, underlying the importance of setting references specific to breed.

Alternatives in Donkey semen cryopreservation: Mare vs. Jenny Colostrum

The aim of this study was to test and compare two new components in extenders for freezing donkey semen: mare colostrum and jenny colostrum. Colostrum was obtained from four mares and four jennies right after the foal's birth. Ejaculates were collected from five fertile donkeys. Sperm samples were pooled, diluted and cryopreserved in three different experimental extender groups: lactose supplemented with egg yolk extender (20%) as the control group, lactose supplemented with jenny colostrum extender (20%), and lactose supplemented with mare colostrum extender (20%). After thawing, we evaluated the sperm motility by means of computer-assisted analysis, viability by SYBR-14 and propidium iodide (PI), membrane functional by HOS test and acrosome integrity by isothiocyanate conjugated with peanut agglutinin (FITC-PNA) and PI. The results demonstrated that lactose-jenny colostrum extender displayed significantly higher values (p < .05) in nearly all parameters evaluated - Total Motility, Viability, HOS test, VCL, VSL, VAP, LIN, STR and WOB -, compared with mare colostrum and egg yolk extenders after thawing. In conclusion, the extender containing jenny colostrum used for donkey semen cryopreservation improved the donkey sperm quality after the freezing-thawing process.