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Effect of Dietary Supplementation with Salmon Oil on Canine Frozen–Thawed Semen
by
, ,
Chiara Milani
1,*,†
,
Marcelo C. Santos
2,†,
Paolo Zucchini
1,
Barbara Contiero
1
,
Stefano Romagnoli
1,
Celia R. Quirino
2 and
Isabel C. N. Cunha
2 1
Department of Animal Medicine, Production and Health, University of Padua, 35020 Padua, PD, Italy;paolo.zucchini@unipd.it (P.Z.)
2
Norte Fluminense State University, Campos dos Goytacazes 28013-602, RJ, Brazil
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Vet. Sci. 2025, 12(9), 797; https://doi.org/10.3390/vetsci12090797 (registering DOI)
Submission received: 30 June 2025
/
Revised: 2 August 2025
/
Accepted: 6 August 2025
/
Published: 23 August 2025
(This article belongs to the Section Veterinary Reproduction and Obstetrics)
Simple Summary
Salmon oil is one of the richest sources of omega-3 polyunsaturated fatty acids. Its use as an oral supplement alongside various diets has been shown to improve many sperm characteristics, including motility and the ability to maintain functional sperm membranes in different animal species, such as bulls, dogs, sheep, poultry and horses. With this study, we evaluated the effect of a 3-month daily fish oil oral administration on the quality of sperm samples subjected to freezing and thawing, as well as the persistence of these effects 3 months after suspension of the supplementation. The results showed that dietary supplementation with salmon oil at a dosage of 180 mg DHA/7 kg body weight per day improved the motility, membrane integrity and viability of frozen–thawed sperm samples in the nine dogs included in this study. After 90 days of fish oil administration, an increase in the sperm motility was observed both after thawing and during a 4-h incubation at 37°C. This improvement was also maintained in samples collected three months after the supplementation of salmon oil was suspended.
Abstract
The objective of this study was to evaluate the effect of omega-3 oral supplementation on frozen–thawed semen quality in stud dogs. Nine healthy male dogs of various ages (2–11 years old), weights (10–36 kg), and breeds were included. Their daily diets were supplemented with salmon oil at 180 mg DHA/7kg BW. Semen was collected before salmon oil oral administration (D0), after 90 days of daily administration (D90), and 90 days following suspension (D180). Samples underwent standard freezing procedures and were stored for at least 30 days; then, they were thawed at 37°C for 1 min. Samples (n = 27) were assessed post-thawing for motility (MOT%), membrane integrity (HOST%), and viability (EN%). A second aliquot of the same samples underwent a thermoresistance test at 37°C, with MOT% and EN% evaluated at 2 and 4 h post-thawing. Data were analyzed using repeated measures ANOVA, considering days of administration (D0, D90, D180), incubation times at 37°C (T0h-T2h-T4h) and their interaction. Significance was set at P < 0.05. An increase in MOT% was observed after 90 days of fish oil administration (D0 = 56.67 ± 5.1% vs. D90 = 71.67 ± 5.1%, p < 0.05); however, this effect was not maintained at D180 (45.56 ± 5.1%). Similar results were observed for HOST and EN. During the thermoresistance test, a significantly higher MOT% was observed at T4h on D90 compared to D0 (p < 0.05). These findings indicate that daily salmon oil supplementation at 180 mg DHA/7 kg for 90 days improves semen motility, membrane integrity and viability, supporting a role for omega-3 fatty acids in semen undergoing cryopreservation.
Keywords:
canine; spermatozoa; polyunsaturated fatty acids; semen cryopreservation; EPA; DHA; fish oil
