The effects of dietary omega fatty acids on pregnancy rate, plasma prostaglandin metabolite levels, serum progesterone levels, and milk fatty-acid profile in beef cows.

The objectives were to determine the effects of feeding supplements rich in omega-6 or omega-3 fatty acids (FA) during the late gestation to the early postpartum and breeding periods on reproduction and milk FA profile in beef cows. For each of two years, at the beginning of period 1 (mid-December), 72 beef cows, calving in January or February, were assigned to diets supplemented with roasted flaxseed (Flax) or roasted soybean (Soybean). For each of two years, after 11 wk (end of period 1), 18 cows of 36 in the Flax group were switched to the soybean supplement and 18 cows of 36 in the Soybean group were switched to the flax supplement (start of Period 2). Cows were bred by timed artificial insemination (TAI) in week 5 of period 2. The FA composition of the milk reflected the FA profile of the oilseed supplements. There were no differences in pregnancy rates among the 4 groups. The treatments had no effect on plasma prostaglandin metabolite levels or ratios at 4 to 11 d postpartum. At 5 to 6 d post- TAI, pregnant cows fed Flax in period 1 had lower (P < 0.05) plasma prostaglandin F metabolite (PGFM) levels and PGFM to prostaglandin E metabolite (PGEM) ratio than cows fed Soybean, but there were no significant differences at 19 to 20 d post-TAI. Cows pregnant from TAI and fed Flax in period 2 had higher (P < 0.05) serum progesterone levels at 5 to 6 d post-TAI than cows fed Soybean, but there was no difference at 19 to 20 d post-TAI. The dietary treatments had no effect on pregnancy rates, but there were some effects on plasma PGFM levels, PGFM to PGEM ratios, and serum progesterone levels. The FA supplements influenced the FA composition of milk.

Les objectifs de la présente étude étaient de déterminer les effets de suppléments alimentaires riches en acides gras (FA) omega-6 ou omega-3 lors de la période fin de gestation au début du postpartum et lors des périodes d'accouplement sur la reproduction et les profils de FA chez les vaches d'embouche. Pour chacune des deux années, au début de la période 1 (mi-décembre), 72 vaches d'embouche, devant vêler en janvier ou février, ont été assignées à des rations supplémentées avec de la graine de lin rôtie (Flax) ou des graines de soya rôties (Soya). Pour chacune des deux années, après 11 semaines (fin de la période 1), 18 des 36 vaches dans le groupe Flax ont été changées au supplément de soya et 18 des 36 vaches du groupe soya ont été changées pour le groupe Flax (Début de la période 2). Les vaches ont été saillies par insémination artificielle minutée (TAI) lors de la semaine 5 de la période 2. La composition en FA du lait représentait le profil de FA des suppléments alimentaires. Il n'y avait pas de différence dans les taux de gestation parmi les 4 groupes. Le traitement n'avait pas d'effet sur les niveaux ou ratios plasmatiques des métabolites des prostaglandines du jour 4 au jour 11 postpartum. Aux jours 5 à 6 post-TAI, les vaches gestantes nourries au Flax durant la période 1 avaient des niveaux significativement (P < 0,05) plus bas de métabolite de la prostaglandine F (PGFM) et des ratios de PGFM au métabolite de la prostaglandine E (PGEM) que les vaches nourries avec le Soya, mais il n'y avait pas de différence significative aux jours 19 à 20 post-TAI. Les vaches gestantes suite à la TAI et nourries avec Flax durant la période 2 avaient des niveaux sériques de progestérone plus élevés (P < 0,05) aux jours 5 à 6 post-TAI que les vaches nourries au Soya, mais il n'y avait plus de différence aux jours 19­20 post TAI. Les traitements alimentaires n'avaient aucun effet sur les taux de gestation, mais il y avait des différences sur les niveaux plasmatiques de PGFM, les ratios PGFM/PGEM, et les niveaux sériques de progestérone. Les FA des suppléments ont influencé la composition en FA du lait.(Traduit par Docteur Serge Messier).

Effects of selenium source on measures of selenium status and immune function in horses.

The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lymphocytes [interferon gamma (IFNγ), interleukin (IL)-2, IL-5, IL-10, tumor necrosis factor alpha (TNFα)], and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Plasma, red blood cell Se, and blood glutathione peroxidase activity were measured. Plasma and red blood cell Se were highest in horses in the organic Se group, compared with that of inorganic Se or control groups. Organic Se supplementation increased the relative lymphocyte expression of IL-5, compared with inorganic Se or no Se. Selenium supplementation increased relative neutrophil expression of IL-1 and IL-8. Other measures of immune function were unaffected. Dietary Se content and source appear to influence immune function in horses, including alterations in lymphocyte expression of IL-5, and neutrophil expression of IL-1 and IL-8.

Les effets d'un supplément de sélénium (Se) ainsi que sa source sur la fonction immunitaire équine n'ont pas été étudiés à fond. On examina dans la présente étude les effets d'un supplément oral en Se et les sources de Se sur des éléments de l'immunité innée et adaptative de chevaux. Quinze chevaux ont été assignés à un de trois groupes (5 chevaux/groupe); témoin, Se inorganique (sélénite de sodium), et Se organique (Se provenant de levures). Les tests de fonctions immunitaires effectués étaient : prolifération lymphocytaire en réponse au mitogène concanaviline A, phagocytose par les neutrophiles, production d'anticorps après vaccination anti-rabique, expression relative des gènes des cytokines de lymphocytes stimulés [interferon gamma (IFNγ), interleukine (IL)-2, IL-5, IL-10, facteur de nécrose tumorale alpha (TNFα)], et de neutrophiles (IL-1, IL-6, IL-8, IL-12, TNFα). Le Se plasmatique et des globules rouges, ainsi que l'activité de la glutathion peroxydase ont été mesurés. Le Se plasmatique et des globules rouges étaient plus élevés chez les chevaux dans le groupe de Se organique, comparativement au groupe recevant le Se inorganique ou le groupe témoin. Un supplément de Se organique entraîna une augmentation d'expression relative d'IL-5 par les lymphocytes, comparativement au Se inorganique ou aucun Se. Un supplément de Se augmenta l'expression relative d'IL-1 et IL-8 par les neutrophiles. Les autres mesures des fonctions immunitaires n'étaient pas affectées. Le contenu et les sources de Se alimentaire semblent influencer les fonctions immunitaires des chevaux, incluant des altérations dans l'expression d'IL-5 par les lymphocytes, et l'expression d'IL-1 et IL-8 par les neutrophiles.(Traduit par Docteur Serge Messier).

Management factors affecting stereotypies and body condition score in nonracing horses in Prince Edward Island.

In North America, there are few representative data about the effects of management practices on equine welfare. In a randomized survey of 312 nonracing horses in Prince Edward Island (response rate 68.4%), owners completed a pretested questionnaire and a veterinarian examined each horse. Regression analyses identified factors affecting 2 welfare markers: body condition score (BCS) and stereotypic behavior. Horses' BCSs were high (mean 5.7, on a 9-point scale) and were associated with sex (males had lower BCSs than females; P < 0.001) and examination date (P = 0.052). Prevalences of crib biting, wind sucking, and weaving were 3.8%, 3.8%, and 4.8%, respectively. Age (OR = 1.07, P = 0.08) and hours worked weekly (OR = 1.12, P = 0.03) were risk factors for weaving. Straw bedding (OR = 0.3, P = 0.03), daily hours at pasture (OR = 0.94, P = 0.02), and horse type (drafts and miniatures had a lower risk than light horses; P = 0.12) reduced the risk of horses showing oral stereotypies. Some of these results contradict those of other studies perhaps because of populations concerned.

The effect of dietary supplementation with blueberry, alpha-tocopherol or astaxanthin on oxidative stability of Arctic char (Salvelinus alpinus) semen.

The objective was to determine the oxidative stability of Arctic char (Salvelinus alpinus) semen following dietary supplementation with lowbush blueberry (Vaccinium angustifolium) product, alpha-tocopherol, alpha-tocopherol+blueberry product, or alpha-tocopherol+astaxanthin. Sperm lipid peroxidation was initiated by challenging with ferrous sulphate/ascorbic acid (Fe(++)/Asc) at level of 0.04/0.2 mmol/L. Addition of blueberry, alpha-tocopherol, or both to char diets inhibited semen lipid peroxidation by: (a) decreasing the rate of sperm lipid peroxidation, an effect which was more pronounced with alpha-tocopherol treatments; and (b) increasing the antioxidant potential of seminal plasma, based on the lipid peroxidation process of sperm and an in vitro chicken brain tissue model. Dietary supplementation with astaxanthin and alpha-tocopherol had the same effect as the supplementation with alpha-tocopherol alone on inhibiting the lipid peroxidation process of sperm and chicken brain. Catalase-like activity increased significantly in sperm of fish fed alpha-tocopherol, blueberry, or both. There was a negative correlation (r= -0.397, P < 0.05) between catalase-like activity in sperm cells and the rate of sperm lipid peroxidation. Seminal plasma alpha-tocopherol levels increased significantly in fish supplemented with alpha-tocopherol alone or in combination with blueberry or astaxanthin. There were negative correlations between seminal plasma alpha-tocopherol levels and lipid peroxidation rates of sperm cells (r= -0.625, P < 0.01) and brain tissue (r= -0.606, P < 0.01). In conclusion, dietary supplementation of blueberry product or alpha-tocopherol inhibited lipid peroxidation in Arctic char semen. Further experiments are needed to test the effect of dietary blueberry and antioxidants on Arctic char semen quality during liquid and cryopreserved storage.

A preliminary equine abuse policy with potential application to veterinary practice.

An equine abuse policy was developed as an adjunct to an equine management survey. If at least 3 of 5 categories caused concern, a report to the authorities was indicated. The policy was not used but, in the absence of other guidelines, it might assist veterinarians considering potential abuse cases.

The selenium status of dairy herds in Prince Edward Island.

Bulk tank milk selenium (Se) concentration was compared with mean serum Se concentration in 15 herds and was found to be an accurate reflection of the herd Se status. The Se status of 109 Prince Edward Island (PEI) dairy herds was monitored for 1 year using bulk tank milk Se concentration. Fifty-nine percent of the herds surveyed were, at some point, found to be marginal or deficient in Se, putting them at risk of disease and suboptimal production. The periods of greatest risk of deficiency were fall and winter, at which time 5% and 4%, respectively, of herds sampled fell in the range considered truly deficient in Se. Herds in which Se supplementation was provided in the form of a commercial dairy concentrate were over 4 times more likely to be Se-adequate than herds not using this method, and adjusted average daily milk yield was 7.6% greater in herds determined to be Se-adequate when compared with Se-marginal herds. We conclude that many dairy producers in PEI are providing insufficient supplementary Se in the ration to meet the recommended Se intake for lactating cows.

Demographics, management, and welfare of nonracing horses in Prince Edward Island.

There are no detailed, representative, horse-level data about equine management practices in different parts of Canada. To help address this, the demographics, management, and welfare of 312 nonracing horses in Prince Edward Island were examined in a randomized, horse-level survey during summer 2002. Owners completed a pretested questionnaire, and a veterinarian examined each horse. Owners were experienced caregivers and the horses were generally in good condition. Areas for improvement included parasite control, dental and hoof care, and tail docking. The mean fecal egg count was 428 eggs per gram; 76% of owners never removed manure from the pasture. Sixty-two percent of horses had never had a veterinary dental examination. Many horses had hoof defects (excessively long hooves, 26.8%; hoof wall breaks, 32.0%; and white line disease, 8.5%). Many (54.9%) draft horses had docked tails. These results suggest owners might benefit their horses by receiving education in aspects of equine care.

Effect of dietary lipid level on fatty acid beta-oxidation and lipid composition in various tissues of haddock, Melanogrammus aeglefinus L.

Haddock (Melanogrammus aeglefinus) is a gadoid fish species that deposits dietary lipid mainly in the liver. The fatty acid (FA) beta-oxidation activity of various tissues was evaluated in juvenile haddock fed graded levels of lipid. The catabolism of a radiolabelled FA, [1-(14)C]palmitoyl-CoA, through peroxisomal and mitochondrial beta-oxidation was determined in the liver, red and white muscle of juvenile haddock fed 12, 18 and 24% lipid in the diet. There was no significant increase in the mitochondrial or peroxisomal beta-oxidation activity in the tissues tested as the dietary lipid level increased from 12 to 24%. Peroxisomes accounted for 100% of the beta-oxidation observed in the liver, whereas mitochondrial beta-oxidation dominated in the red (91%) and white muscle (97%) of juvenile haddock. Of the tissues tested, red muscle possessed the highest specific activity for beta-oxidation expressed on a per mg protein or per g wet weight basis. However, white muscle, which forms over 50% of the body mass in gadoid fish was the most important tissue in juvenile haddock for overall FA catabolism. The total lipid and FA composition of these tissues were also determined. This study confirmed that the liver was the major lipid storage organ in haddock. The hepatosomatic index (HSI; 10.0-15.2%) and lipid (73.8-79.3% wet wt.) in the liver increased significantly as dietary lipid was increased from 12 to 24% lipid. There was no significant increase in the lipid composition of the white muscle (0.8% wet wt.), red muscle (1.9% wet wt.) or heart (2.5% wet wt.).