Jan Kivipelto

Effect of dietary omega-3 fatty acid source on plasma and red blood cell membrane composition and immune function in yearling horses

To determine the effect of different sources of dietary n-3 fatty acids (FA) on plasma and red blood cell (RBC) FA composition and immune response, 18 Quarter Horse yearlings were randomly and equally assigned to 1 of 3 treatments: encapsulated fish oil (n = 6), milled flaxseed (n = 6), or no supplementation (control, n = 6). Fish oil contained 15 g of eicosapentaenoic acid (C20:5n-3) and 12.5 g of docosahexaenoic acid (C22:6n-3), and flaxseed contained 61 g of alpha-linolenic acid (C18:3n-3) per 100 g of FA. Horses had free access to bahiagrass pasture during the active growing season and were individually fed a grain mix concentrate at 1.5% BW/d. Fish oil and flaxseed were mixed into the concentrate in amounts to provide 6 g of total n-3/100 kg of BW. Horses were fed their respective treatments for 70 d. Blood samples were obtained to determine plasma and RBC FA composition and for isolation of peripheral blood mononuclear cells. Peripheral blood mononuclear cells were stimulated with concanavalin A and phytohemagglutinin (PHA) to determine lymphocyte proliferation and were challenged with lipopolysaccharide to determine PGE(2) production. In vivo inflammatory response was assessed on d 70 by measuring skin thickness and area of swelling in response to intradermal injection of PHA. Treatment did not affect BW gain, which averaged 0.6 +/- 0.03 kg/d. Horses fed fish oil had greater (P < 0.05) proportions of eicosapentaenoic acid, docosahexaenoic acid, and sum of n-3 in plasma and RBC compared with those in the flaxseed and control treatments. In addition, plasma arachidonic acid was greater (P < 0.05) and plasma linoleic and alpha-linolenic acids were less (P < 0.05) in the fish oil treatment compared with the flaxseed and control treatments. Dietary treatment did not affect lymphocyte proliferation or PGE(2) production. Across treatments, the peak increase in skin thickness was observed 4 to 8 h after PHA injection. At 4 h postinjection, horses fed fish oil and those fed flaxseed had a greater increase in skin thickness than those in the control treatment (P < 0.05) and horses fed fish oil had a larger area of swelling than those in the control treatment (P < 0.05). Skin thickness remained greater (P < 0.05) in horses fed flaxseed than in control horses 6 h after injection. Although fed to supply a similar amount of n-3 FA, fish oil had a greater impact on plasma and RBC n-3 FA content than did flaxseed. However, supplementing horses with both fish oil and flaxseed resulted in a more pronounced early inflammatory response to PHA injection as compared with nonsupplemented horses.

A REVIEW OF THE USE OF ACUPUNCTURE FOR TREATMENT OF EQUINE BACK PAIN

Summary Poor performance due to back pain is a commonproblem in the horse industry. Alternative modalities using herbal medicine and acupuncture are useful and effective for this condition. Eleven acupuncture techniques for the treatment of equine back pain are summarized in this paper. Acupuncture treatment for back muscular atrophy and acupuncture mechanism of pain relief are also discussed.

Supplementation of broodmares with copper, zinc, iron, manganese, cobalt, iodine, and selenium ☆ ☆☆ ★

In experiment 1, 6 pregnant mares received a concentrate that contained a trace mineral premix that provided 14.3 mg Cu, 40 mg Zn, 28 mg Fe, 28 mg Mn, 0.08 mg Co, 0.16 mg I, and 0.16 mg Se/kg concentrate (group A). Seven mares received the same concentrate plus 502 mg Zn and 127 mg Cu once daily (group B). No differences (P > .05) in foal growth data, or Cu, Zn, and Fe concentrations of mare milk, mare serum, or foal serum were observed. In experiment 2, 6 pregnant mares received the same concentrate as group A (group C), and 8 mares received the same concentrate fortified with 4× the trace mineral premix (group D). Group C mares had higher serum Zn concentration at 1 day (P < 0.01) and 56 days (P < 0.04). Group C mares had higher milk Fe concentration at 28 days (P < .01), and group D mares had higher milk Cu concentration at 56 days (P < .01). Group C foals had higher serum Cu concentration at 14 days (P < .03). The results from this study provide no evidence to indicate that supplementing late gestating and lactating mares with higher dietary trace mineral levels than those recommended currently by NRC has any influence on foal growth and development, or on the Cu, Zn, and Fe concentrations of the mare milk, mare serum, or foal serum.

Haematological findings in pregnant, postparturient and nursing mares

Venous blood samples were collected from 16 Thoroughbred and Quarter Horse mares during late pregnancy (approximately one month before parturition), approximately 6 h after parturition, one month after parturition and 4 months after parturition when the foals were weaned. There were no significant differences over time for haematocrit, mean cell volume, mean cell haemoglobin concentration, platelet count or mean platelet volume. The icterus index was significantly higher, and the total plasma protein concentration was slightly lower, during late pregnancy than when nursing. Plasma fibrinogen concentration and total leucocyte counts were highest shortly after birth. Results from differential leucocyte counts revealed that the increased total leucocyte count measured shortly after birth was the result of increased numbers of neutrophils. There were no significant differences in absolute lymphocyte, monocyte or basophil counts, but the number of eosinophils was significantly lower shortly after birth. Total serum iron concentration and percentage saturation of transferrin with iron were highest shortly after birth. There was no significant difference in iron binding capacity over time. Serum ferritin and cortisol concentrations were lowest during late pregnancy, but the mean ferritin value was not significantly different from other time periods. The addition of iron and other mineral supplements to the basic concentrate fed at the University of Florida Horse Research Unit did not have a measurable effect on any haematological parameter evaluated in mares.

Growth and development of yearling horses fed either alfalfa or coastal bermudagrass: Hay and a concentrate formulated for bermudagrass hay

Two experiments were conducted with yearling horses to determine whether the use of a concentrate designed to be fed with Coastal bermudagrass hay would cause growth differences or skeletal abnormalities when fed with western alfalfa hay. In experiment 1, 13 thoroughbred and quarterhorse yearlings, 332.8 ± 8.5 days, of age were assigned at random within breed and gender subgroups to 1 of 2 diets: (1) alfalfa hay plus a 12.7% CP concentrate and (2) coastal bermudagrass hay plus the same concentrate. The horses were housed in drylot paddocks in groups of 3 or 4 animals and group fed the hay at 1 kg/100 kg BW daily. The concentrates were fed individually to appetite for two 1.5-hour feeding periods daily for 112 days. Orts were weighed back daily. The animals were weighed, measured, and blood samples collected at the start of the experiment and at 28-day intervals for 112 days. Radiographs of the third metacarpal were made on day 0, 56, and 112 for estimation of bone mineral content. In experiment 2, 15 thoroughbred and quarterhorse yearlings, 345.6 ± 8.4 days of age, were used to repeat the experiment. The concentrate fed in this experiment contained 12.4% CP. In experiment 1, the hay protein content was less than anticipated, resulting in a protein intake below NRC1 recommendations. In experiment 2, the hay protein was higher and more typical of NRC1 values. In both experiments, feed intake of the 2 diets was not different (P > .10). Weight gain (P = .0136, P = .0330), heart girth gain (P = .0084, P= .0044), and hip height gain (P = .0165, P = .0137) were higher for the alfalfa fed yearlings for experiment 1 and experiment 2, respectively. Withers height gain (P = .0079) and body length gain (P = .0232) were also greater for the alfalfa fed yearlings on experiment 2. Bone mineral content and bone metabolism indicators were not influenced by diet (P > .10).

Influence of dietary fat and time of hay feeding on growth and development of yearling horses

Summary Seventeen Thoroughbred and Quarter Horse yearlings were used in a 2×2 factorial experiment to determine 1) whether adding fat (5% corn oil) to the concentrate would influence feed intake, growth and development and 2) whether time of hay feeding would influence energy metabolism on the basal and added fat diets. Yearlings were assigned at random, within breed and gender subgroups, to one of four diets: B-I, basal concentrate with Coastal Bermuda grass ( Cynodon dactylon ) hay fed immediately after the concentrate; B-D, basal with hay fed 3.5 hr after the concentrate; F-I, basal + fat with the hay fed immediately; and F-D, basal + fat with the hay fed 3.5 hr after the concentrate. The basal concentrate was formulated to meet or exceed NRC (1989) recommendations when fed with the hay. The basal + fat concentrate was formulated at 9.7% higher digestible energy than the basal concentrate and all of the other nutrients were increased proportionately so if the intake was reduced, the yearlings would still meet nutrient needs. The concentrates were fed individually to appetite for two 1.5-hr feeding periods daily in 1.5×3.0 m slip stalls. Hay was group fed in the paddocks at a rate of 1.0 kg/100 kg BW daily divided into two equal feedings. Animals were housed in four 9.1×34.9-m drylot paddocks with three, four, or five animals in each paddock. The mean age at the start of the experiment was 377±8 days. Weight and body measurements for withers height, heart girth, body length, and hip height were taken at the start of the experiment and at 28-day intervals for 84 days. Radiographs for bone mineral estimates were made at the start and completion of the experiment. During the final 28-day period of the feeding trial, three animals from each experimental group were randomly selected for a 24-h period of blood sampling to evaluate the effects of the diets on blood glucose and insulin. Fat addition to the concentrate reduced the daily concentrate DM (P=0.0187) and total feed DM (P=0.0021) intake. When feed intake was expressed as a function of BW, concentrate and total feed intakes were 1.33 and 2.14 kg/100 kg BW daily and were not influenced by diet (P>0.1). Colts consumed more concentrate DM (P=0.0039) and total feed DM (P=0.0022) than fillies. The yearlings gained an average of 0.60 kg/d for the 84 days. Weight gain, body measurements and bone mineral deposition were not influenced by gender or diet. Mean plasma glucose concentrations were higher (P=0.05) in yearlings consuming the basal concentrate with hay fed immediately than when hay feeding was delayed. When fat was fed, the time of hay feeding had no effect on plasma glucose concentrations (P>0.05). Plasma glucose and insulin were lowest just prior to the morning feeding and peaked two to three hours after both morning and afternoon feedings. Fat supplementation reduced plasma insulin (P=0.001). Results suggest that the addition of 5% corn oil to a yearling concentrate may reduce feed intake but will not reduce growth and development of the animal if other nutrients are supplied at concentrations that provide for the animals daily needs. Delaying hay feeding may be advantageous to growing horses as it may allow the concentrate to move down the tract at a slower rate reducing the glucose peaks.

A comparison of two programs (pyrantel tartrate administered daily and 3X pyrantel pamoate adminitered at 8-week intervals) for the reduction of tapeworm EPG in the horse

Summary A 26-week study was conducted with 24 horses to compare the effectiveness of two different treatment regimens in reducing the number of tapeworm eggs per gram (EPG) of feces. Ten horses were treated daily with 2.6 mg/kg of pyrantel tartrate (approved normal dosage for nematodes). Eleven horses received pyrantel pamoate at 8-week intervals at 19.8 mg/kg (3X the normal use for nematodes). Three horses served as controls and received ivermectin at 8-week intervals. Levels of tapeworm EPG were monitored at 2-week intervals for the duration of the 26-week period of study. Prior to administration of the first treatment, all 24 horses had positive EPG counts. Following the second week of treatment, no tapeworm eggs were detected in fecal samples of the 10 horses treated with pyrantel tartrate. Of the 11 horses treated with 3X pyrantel pamoate at 8-week intervals, one to two at each sample collection date had positive tapeworm EPG counts through the tenth week following the initial treatment, that is, through two weeks following the second 3X pyrantel pamoate treatment. Of the three control horses treated only with invermectin, at least one, and sometimes all three, had positive EPG counts at each collection date, indicating continuous tapeworm infection.

Hematologic development in foals receiving intravenous iron supplementation

Summary Seventeen healthy Thoroughbred and Quarter Horse foals were divided into control (n=8) and treated (n=9) groups and studied from birth until 4 months of age. Foals in the treated group were intravenously injected with an experimental drug containing 0.4 g of iron in the form of a polynuclear complex of carbohydrate and ferric hydroxide on days 7, 14, 21 and 28, for a total dosage of 1.6 g of iron. Foals had access to Bermuda grass hay and Bahia pasture. A creep feed formulated with no trace mineral supplement was provided after two months of age. Hemoglobin concentration, hematecrit, erythrocyte counts, mean cell volume, microcyte numbers, plasma protein, fibrinogen, total leucocyte count, serum iron, total iron binding capacity and serum ferritin values were determined at 8 different ages. On the basis of analysis of variance at P

Serum lipoprotein, biochemical and hematologic analyses in equine infectious anemia sero-positive ponies*

Summary Blood samples were analyzed from a group of 24 ponies, 19 of which had tested sero-positive for equine infectious anemia at three consecutive intervals. The five ponies which had tested negative on all occasions served as a control group. Physical examination of the animals including temperature, pulse, respiration, qualitative assessment of conjunctival icterus and depression revealed no significant abnormalities. Sera were analyzed for alkaline phosphatase and gamma glutamyl transferase activities, triglyceride, cholesterol, total and direct bilirubin, and iron concentrations and iron binding capacities. Serum lipoproteins were separated into alpha and beta fractions by agarose gel electrophoresis. Serum haptoglocin and complete blood profiles were also determined. The packed cell volume, serum haptoglobin concentrations and gamma glutamyl transferase activities were significantly decreased and a slight monocytosis was noted in the EIA positive group. No differences in serum alpha and beta lipoproteins or alpha/beta ratio were seen. Complete blood counts including differential white cell quantitation were also unaffected. The animals were mildly anemic with some signs of liver involvement. Alterations of serum lipoproteins, however, were not observed. It is concluded that previously reported lipoprotein alterations in animals with equine infectious anemia were most likely due to anorexia of advanced disease secondary to the clinical illness and not a primary effect of virus infection.