Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA.
Material And Methods: Holstein cows calving in January were assigned into winter group (n = 42), while cows calving in August were assigned into summer group (n = 42). Blood samples were collected from the jugular vein 21, 14, and 7 days before calving, at calving (0 day), and 7, 14, and 21 days after calving. Reproductive parameters obtained from farm records were evaluated.
Results: In both groups of cows, GSH-Px activity decreased from 21 days before calving to day 0, and it gradually continued to increase until 21 days after calving. GSH-Px activity was higher in winter group compared to summer group during the transition period (P < 0.05). MDA levels in both groups increased over time starting from 21 days before calving to 0 day, but it gradually decreased thereafter. MDA levels were higher in summer group compared to winter group during the transition periods (P < 0.05). Summer group of cows showed higher intervals of calving-to-oestrus, calving-to-conception, and higher insemination index (P < 0.01). Negative correlation was recorded between GSH-Px and MDA during all examination days (P < 0.01). MDA levels correlated with calving to conception interval on day 21 before calving and day 0 (P < 0.01) and insemination index on day 0 and 21 days after calving (P < 0.01). GSH-Px activity was negatively correlated with calving to conception interval on day 21 before calving, day 0, and 21 days (P < 0.01) after calving. Negative correlation on day 21 before calving and day 0 was also determined between GSH-Px and insemination index (P < 0.01).
Conclusion: This study showed that blood oxidant and antioxidant levels have affected the fertility parameters in cows under seasonal variations.
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http://dx.doi.org/10.1515/jvetres-2017-0067 | DOI Listing |
Vet Immunol Immunopathol
January 2025
Group for Reproduction in Animals, Vaccinology & Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States.
Animal
December 2024
National Research Institute of Animal Production, ul. Krakowska 1, 32-083 Balice, Poland.
Precise genetic parameter estimates can allow the breeding value evaluation to be adjusted to meet European requirements and to enable participation in the international evaluation of Simmental bulls conducted by Interbull. Genetic parameters were estimated for a multitrait multilactation random regression test-day model for milk in Simmental cattle in Poland. Data came from the official Polish national recording system.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Boehringer-Ingelheim Animal Health, Level 2, 3 Te Kehu Way, Mount Wellington, Auckland, New Zealand.
The aims of this study were to assess the effect of meloxicam at the time of lameness treatment for hoof-horn (HH) lesions in dairy cattle on 1) time to lameness soundness post trimming and block application and 2) reproductive success Five seasonal-calving pasture-based dairy farms located in the Waikato region of New Zealand were enrolled into a randomized clinical interventional trial. Farmers were tasked with identifying lame animals over a period of approximately -4 to 6 weeks relative to the herd start of mating (HSM), with lameness subsequently confirmed with lameness score (LS) by trained technicians (0-3 scale, where ≥2 are considered lame). Animals with a LS ≥2 were examined by a veterinarian who then enrolled animals if they presented lame with HH (white-line or sole) lesions.
View Article and Find Full Text PDFJ Anim Breed Genet
January 2025
Animal Breeding and Genomics Group, Wageningen University & Research, Wageningen, The Netherlands.
Holstein cattle account for the largest proportion of dairy cattle in China. The current China Performance Index (CPI) consists mainly of production traits. To derive economic values (EV) of additional traits for balanced breeding programs, a bio-economic model is necessary.
View Article and Find Full Text PDFAm J Vet Res
January 2025
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA.
Objective: To describe immune responses following administration of experimental Salmonella Dublin siderophore receptor protein (SRP) vaccines in Holstein heifer calves with adequate passive antibody transfer.
Methods: Calves were randomly assigned to receive placebo, vaccination with S Dublin SRP in adjuvant A, or vaccination with S Dublin SRP in adjuvant B at 7 ± 3 days of age and 3 weeks later. Before each vaccination, 4 and 8 days after the second vaccination (postvaccination), and 61 to 91 days postvaccination, S Dublin antibody titers were measured.
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