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Our objective was to characterize the effects of supplementing newborn calves with n-3 fatty acids (FA) and α-tocopherol on blood lipid profiles and oxidant status in early life. Sixteen calves received 0 or 60 mL of 1:1 fish and flaxseed oil with 200 mg of α-tocopherol in 2.8 L of colostrum within 6 h after birth. Colostrum was >22% on the Brix scale. Blood was sampled on d 1, 2, 4, 7, 14, and 21 after birth for assessment of plasma polyunsaturated FA, α-tocopherol, total serum protein, and oxidant status index, an indirect indicator of oxidative stress that examines the balance between the concentration of reactive oxygen and nitrogen species and antioxidant capacity in serum. Health was observed daily. Weight and hip height were recorded at birth, 3 wk, and 8 wk. Data were analyzed with a Mixed procedure of SAS 9.4 (SAS Institute Inc., Cary, NC). Treatment did not alter concentration of total protein in blood serum, prevalence of diarrhea or other signs of disease, or rate of growth. Feeding n-3 FA and α-tocopherol increased plasma concentrations of the n-3 FA, including α-linolenic, eicosapentaenoic, and docosahexaenoic acids, with a concomitant decrease in oxidant status index during the first week of life. Concentrations of α-tocopherol decreased with supplementation, but all calves maintained adequate concentrations. Oxidant status index of treated calves returned to the level of control calves by d 14. We conclude that a colostrum supplement of n-3 FA and α-tocopherol is safe to administer to newborn calves, reduces oxidant status in the first week of life, and may improve health and performance.

Diseases that occur during the transition period are exacerbated when cows are unable to cope with an increased pro-oxidant load that results in oxidative stress. Dairy cattle are routinely supplemented with the vitamin E analog α-tocopherol to mitigate the severity of oxidative stress. Nonetheless, oxidative stress remains a disease predisposing condition for many dairy cattle. A better method of optimizing the antioxidant functions of vitamin E is needed. α-Tocopherol is only 1 of 8 analogs of vitamin E, all of which have varying antioxidant properties in other mammals, albeit a shorter physiological half-life compared with α-tocopherol. A primary bovine mammary endothelial cell oxidant challenge model was used to determine functions of certain vitamin E analogs. The aim of this study was to determine if other analogs, namely γ-tocopherol or γ-tocotrienol, have antioxidative functions in bovine cells and if these functions may protect cellular viability and endothelial function from oxidant damage. Physiological (10 μM) and supraphysiological (50 μM) concentrations of γ-tocopherol and γ-tocotrienol had a greater capacity to reduce accumulated reactive oxygen species derived from a nitric oxide donating pro-oxidant antagonist, when compared with α-tocopherol, after 30 min to 6 h of treatment. Further, γ-tocotrienol (10 μM) decreased cell cytotoxicity to a greater amount than other analogs at like concentrations, whereas γ-tocopherol (10 μM) reduced lipid peroxidation and apoptosis more effectively than other analogs. Last, α-tocopherol (5 and 10 μM) and γ-tocopherol (5 and 10 μM) significantly slowed pro-oxidant induced loss of endothelial cell barrier integrity over a 48-h period using an electrical cell-substrate impedance sensing system. Concerningly, γ-tocotrienol drastically reduced the endothelial barrier integrity at only 5 μM despite no apparent effect on cellular viability at like concentrations. γ-Tocotrienol, however, was also the only analog to show significant cytotoxicity and reductions in viability at supraphysiological doses (25 and 50 μM). Our results suggest that γ-tocopherol has antioxidant activities that reduces cellular damage and loss of function due to oxidant challenge as effectively as α-tocopherol. These data set the foundation for further investigation into the antioxidant properties of vitamin E analogs in other bovine cells types or whole animal models.

Vitamin E comprises 8 fat-soluble isoforms: α-, β-, γ-, and δ-tocopherol and α-, β-, γ-, and δ-tocotrienol. Yet the body preferentially uses α-tocopherol, and only α-tocopherol supplementation can reverse vitamin E deficiency symptoms. However, other isoforms influence many biological functions in the body, including inflammation and stress. Therefore, the study objective was to determine metabolic and performance responses in young calves fed diets containing a constant amount of α-tocopherol and increasing amounts of soybean oil-derived mixed γ- and δ-tocopherols. Holstein calves [n = 48; 2-3 d of age; 40.2 kg of initial body weight (BW), standard error = 0.54] were assigned to receive approximately 0, 5, 10, or 15 mg/kg of BW daily (treatments T0, T1, T2, and T3, respectively) of mixed tocopherols (TMIX) provided in milk replacer (MR) and calf starter. The TMIX liquid contained 86% γδ-tocopherols and 9% α-tocopherol. Milk replacers were formulated to contain approximately 0, 400, 800, or 1,200 mg of TMIX/kg for treatments T0, T1, T2, and T3, respectively. Calf starters were formulated to contain approximately 0, 250, 500, or 750 mg of TMIX/kg for treatments T0, T1, T2, and T3, respectively. Mean consumption of γδ-tocopherols was 0.0, 6.5, 14.3, and 20.5 mg/kg of BW, respectively. Milk replacer contained 24% crude protein (CP) and 20% fat on a dry matter (DM) basis. Calf starters were pelleted and offered for ad libitum consumption from 0 to 56 d. Starters contained 18 to 20% CP and 9 to 12% starch in the DM. On d 28, 4 calves per treatment were randomly selected for slaughter, and necropsy was performed. Samples of liver, duodenum, ileum, and trapezius muscle were collected and stored before analysis for α-, β-, γ-, and δ-tocopherols and δ-tocotrienol. Data were analyzed using a completely randomized design using mixed model ANOVA with orthogonal polynomials to determine linear and quadratic effects of TMIX. Repeated-measures analyses were performed for data collected over time. Increasing dietary TMIX increased or tended to increase change in hip width at 28 and 56 d, respectively, and improved average daily BW gain and gain-to-feed ratio at 56 d. Increasing TMIX reduced plasma xanthine oxidase at 0 h and tended to reduce concentrations at 24 h following vaccination with 2 commercial vaccines on d 28; however, we detected no effect of TMIX following vaccination on d 56. Concentration of α-tocopherol in skeletal muscle declined quadratically with increasing TMIX, whereas ileal and liver γ-tocopherol increased linearly with increasing TMIX. The number of mucin-2 cells in the ileum increased more than 2-fold in calves fed T3. Addition of mixed tocopherols to diets of young dairy calves improved animal growth and altered indices of antioxidant metabolism.

Conjugated linoleic acids (CLA) are well known as milk fat-reducing feed supplements in diets for lactating ruminants. However, their effects on milk concentrations of fat-soluble vitamins are unknown. This study was performed to investigate the hypothesis that CLA affect the concentrations of retinol and tocopherol in ewe milk. For that purpose, group-housed Merino ewes (101 ± 13.7 kg) nursing twin lambs and fed with a hay:concentrate diet were supplemented with either 45 g of a rumen-protected CLA supplement containing 3.4 g of cis-9,trans-11-CLA and 3.4 g of trans-10,cis-12-CLA (CLA group, n=11) or with 45 g of a hydrogenated vegetable fat (control group, n=12) per ewe per day during the first 6 wk of lactation. Feed intake was recorded daily (concentrate) or weekly (hay) per group. Milk spot samples were collected at the beginning of the experiment (5 ± 2.4 d postpartum) and then weekly after lambs had been separated for 2 h from their mothers. The milk fat content was determined and feed and milk were analyzed for concentrations of α-, γ-, and δ-tocopherol and for retinol by HPLC. Dietary intake of tocopherol and retinol was similar in both groups. Feeding CLA decreased milk fat concentration by 23% on average, and during the first 3 wk of the study milk tocopherol concentration tended to be increased by feeding CLA (+17%), but retinol concentrations were not influenced. When related to milk fat, CLA feeding significantly increased both milk tocopherol (+40%) and retinol (+32%) and these effects were evident during the whole experimental period corresponding to the first half of lactation.

In the present study, a methanol-fluorescence-based HPLC method was validated for its use to quantify α-tocopherol and γ-tocopherol in raw milk, whole UHT milk, partially skimmed UHT milk, whole pasteurized milk, and partially skimmed pasteurized milk. Repeatability and reproducibility, calculated as relative standard deviation of 10 measurements within the same day and 30 measurements across 3 d, respectively, were always below 5% for both tocopherols concentrations and retention times. Recovery was assessed through 3 spiking levels and it ranged from 89 to 107%. The method was able to detect the expected declines in tocopherols in milk exposed to UHT or skimming treatments. Vitamin E, calculated as the sum of α-tocopherol and γ-tocopherol, was similar in whole pasteurized and raw milk, averaging 1.57 and 1.56 mg/L, respectively, followed by whole UHT (1.33 mg/L), partially skimmed pasteurized (0.77 mg/L), and partially skimmed UHT milk (0.61 mg/L).

The 4 major tocopherol isoforms differ in their biochemical reactivity and cellular effects due to basic chemical structural differences. Alpha-tocopherol has been well studied regarding effects on bovine polymorphonuclear leukocyte (PMN) function and its involvement in respiratory burst. However, no studies to date have identified the effects of supplementing a mixed tocopherol oil (Tmix) particularly enriched in non-α tocopherol isoforms (i.e., γ- and δ-isoforms) on fundamental immunometabolic changes in dairy cows. Therefore, the objectives of this study were to determine whether short-term feeding of vegetable oil-derived Tmix alters specific biomarkers of metabolism, whole-blood leukocyte populations, respiratory burst, immunometabolic-related gene expression of PMN, or gene expression of isolated PMN when challenged with lipopolysaccharides (LPS). Clinically healthy multiparous lactating Holstein cows (n = 12; 179 ± 17 d in milk, 40.65 ± 3.68 kg of milk yield) were fed Tmix (620 g/d) for 7 consecutive days. Jugular blood (EDTA anticoagulant) was collected from all cows on d 0 before treatment initiation and again on d 7 after Tmix feeding. Total stimulated respiratory burst activity (RBA) and leukocyte populations were assessed in whole blood, and tocopherol isoform concentrations, metabolites, and hormones were measured in plasma. For gene expression analysis, isolated PMN from cows before and after Tmix feeding were incubated with LPS at a final concentration of either 0.0 or 1.5 µg/mL. Feeding of Tmix for 7 d increased the concentrations of α- and γ-tocopherol. The Tmix did not alter plasma insulin but decreased cholesterol. The Tmix did not alter whole-blood RBA or the leukocyte populations. The LPS challenge increased the expression of proinflammatory genes TNFA and IL6. However, Tmix treatment did not alter the patterns of LPS-affected expression of genes (e.g., TNFA, ITGB2, PPARA, and RXRA) associated with the immune or metabolic response. In conclusion, short-term feeding of Tmix may have no negative effect on animal health as Tmix increased α- and γ-tocopherol concentrations in blood and did not impair whole-blood RBA or alter leukocyte populations. The data provide further support that the α- and γ-tocopherol isoforms do not interfere with normal immune or metabolic function.

Vitamin E supplementation, when combined with high blood α-tocopherol (6.25 μg/mL) at dry off, has been reported to unexpectedly increased the risk for clinical mastitis in dairy cows. Furthermore, higher levels of oxidative stress in the postpartum period were related to higher risk of mastitis. The objective of the present study was to determine the relationship between various serum biomarkers of oxidative status, incidence of mastitis, and blood α-tocopherol concentrations at dry off and at calving. A total of 146 dairy cows from a commercial farm were used in an observational field study. All cows were supplemented with 3,000 and 50 IU/cow per day of all-rac-α-tocopherol during the dry period and lactation, respectively. Blood samples were collected at dry off and at calving. Serum was analyzed for α-tocopherol, levels of reactive oxygen metabolites (ROM), thiol groups (SH), and ferric-reducing ability. Three α-tocopherol groups at calving were created: high (3 μg/mL), medium (2-3 μg/mL), and low (2 μg/mL). Three α-tocopherol groups at dry off were created: high (6.25 μg/mL), medium (4.25-6.25 μg/mL), and low (4.25 μg/mL). All cases of clinical mastitis that occurred during the dry period and the entire subsequent lactation were verified by a veterinarian. No differences were observed in the incidence of mastitis between the 3 α-tocopherol groups based on the serum levels at dry off. Incidence of mastitis was 4 times lower in the high and medium groups when compared with the corresponding value for the low-α-tocopherol group based on the serum levels at calving. Lower levels of ROM and SH at dry off and at calving were found in the group of cows with the highest α-tocopherol values at dry off when compared with the corresponding values in the low-α-tocopherol group. The ROM values at dry off but not at calving were lower in the group of cows with the highest α-tocopherol values at calving when compared with the corresponding values in the low-α-tocopherol group. No differences were observed in ferric-reducing ability values between the 3 α-tocopherol groups at dry off or calving. No differences were observed in all biomarkers of oxidative status between healthy cows and those with mastitis. Thus, blood α-tocopherol is inversely related to certain biomarkers of oxidative stress in the postpartum period and incidence of mastitis. However, reduction in the incidence of mastitis is not mediated through a reduction in the levels of various biomarkers of oxidative stress.

The objective of the present study was to examine the relationships between blood concentrations of fatty acids, β-hydroxybutyrate (BHB), and α-tocopherol during the periparturient period in dairy cows. Blood samples were collected from 131 cows belonging to 4 different commercial dairy farms in southeastern Europe (Greece and Italy). We determined blood concentrations of fatty acids, BHB, and α-tocopherol at dry-off, at calving, and 30d postpartum. Results indicated that fatty acid concentrations were low at dry-off, reached maximum value at calving, and then declined at 30d postpartum. In fact, fatty acid concentrations at 30d postpartum were 50% lower than at calving. In contrast, BHB concentrations were low at dry-off, increased by 27% at calving, and continued to increase by another 20% at 30d postpartum. Overall, we found a weak correlation between fatty acids and BHB throughout the periparturient period. Concentrations of α-tocopherol were lowest at calving, and we detected no differences in α-tocopherol concentrations at dry-off or 30d postpartum. Negative correlations between fatty acids and α-tocopherol were highly significant at 30d postpartum and approached the level of significance at dry-off. However, both correlations became nonsignificant following the adjustment of α-tocopherol with cholesterol, indicating that the correlations were a reflection of changes in lipid transport. We found significant negative correlations (strong at dry-off and weak at 30d postpartum) between BHB and α-tocopherol after adjustment with cholesterol. The physiological basis for the negative correlations between BHB and α-tocopherol, especially that at dry-off, is not known and should not be taken to imply a cause-effect relationship. However, it opens the door to investigating the effects of vitamin E on liver function in dairy cows.

The objective of this experiment was to determine whether source of supplemental alpha-tocopherol fed to periparturient dairy cows affects neutrophil function and vitamin E status of the cow and the neonatal calf. Starting 14 d before anticipated calving and continuing until 14 d post-parturition, cows were fed diets with no supplemental vitamin E or with 2,500 IU/d of vitamin E from all-rac alpha-tocopheryl acetate or RRR alpha-tocopheryl acetate. All-rac alpha-tocopherol contains equimolar amounts of all 8 stereoisomers, whereas the RRR contains only the RRR isomer. Concentrations of alpha-tocopherol in cow plasma, colostrum, milk, and blood neutrophils were greatest for the RRR treatment, intermediate for all-rac, and lowest for cows fed no supplemental vitamin E. The concentration of alpha-tocopherol in plasma of newborn calves was very low and not affected by treatment but after 6 feedings of their dam's colostrum or milk, concentrations in calf plasma followed the same treatment pattern as cow plasma. The number of bacteria phagocytized was greater by neutrophils from cows fed all-rac vitamin E than for the other 2 treatments, which resulted in a greater number of bacteria being killed. For cows fed all-rac vitamin E, the RRR isomer comprised about 20% of the alpha-tocopherol consumed but approximately 60% of the alpha-tocopherol in plasma and milk. This enrichment was caused mostly by an almost complete discrimination against the 2S isomers. Because all-rac alpha-tocopherol is 50% 2S isomers, these data suggest that 1 g of all-rac tocopheryl acetate is equivalent to 0.5 g of RRR tocopheryl acetate.

The fat-soluble vitamin E comprises the 8 structurally related compounds (congeners) α-, β-, γ-, and δ-tocopherol (with a saturated side chain) and α-, β-, γ-, and δ-tocotrienol (with a 3-fold unsaturated side chain). Little is known regarding the blood and liver concentrations of the 8 vitamin E congeners during the transition from pregnancy to lactation in dairy cows. We thus quantified tocopherols (T) and tocotrienols (T3) in serum and liver and hepatic expression of genes involved in vitamin E metabolism in pluriparous German Holstein cows during late gestation and early lactation and investigated whether dietary supplementation (from d 1 in milk) with conjugated linoleic acids (CLA; 100 g/d; each 12% of trans-10,cis-12 and cis-9,trans-11 CLA; n = 11) altered these compared with control-fat supplemented cows (CTR; n = 10). Blood samples and liver biopsies were collected on d −21, 1, 21, 70, and 105 (liver only) relative to calving. In both groups, the serum concentrations of αT, γT, βT3, and δT3 increased from d −21 to d 21 and remained unchanged between d 21 and 70, but were unaffected by CLA. The concentrations of the different congeners of vitamin E in liver did not differ between the CTR and the CLA groups. In both groups, the concentrations of the vitamin E forms in liver changed during the course of the study. The hepatic mRNA abundance of genes controlling vitamin E status did not differ between groups, but α-tocopherol transfer protein and tocopherol-associated protein mRNA increased with time of lactation in both. In conclusion, the concentrations of vitamin E congeners and the expression of genes related to vitamin E status follow characteristic time-related changes during the transition from late gestation to early lactation but are unaffected by CLA supplementation at the dosage used.

The objective of this study was to investigate parenteral vitamin E for the prevention of peripartum disease in dairy cows. A randomized clinical trial was conducted in 21 commercial dairy herds. Cows (n = 1142) were randomly assigned to receive either a single subcutaneous injection of 3000 IU of vitamin E, or placebo, 1 wk before expected calving. Serum alpha-tocopherol was significantly increased in treated cows at 7 and 14 d, but not at 21 d after injection. Overall, there were no significant differences between treatment groups in the incidence of retained placenta, clinical mastitis, metritis, endometritis, ketosis, displaced abomasum, or lameness. However, there was a conditional benefit of treatment for reduction of the incidence of retained placenta. Cows with marginal pretreatment vitamin E status (serum alpha-tocopherol to cholesterol mass ratio < 2.5 x 10(-3)) that received an injection of vitamin E tended to have reduced risk of retained placenta. However, in cows with adequate serum vitamin E, there was no reduction in the incidence of any disease. For clinical application, primiparous animals were most likely to benefit from prepartum injection of vitamin E.

The oxidative stability of fish oil blended with milk products was evaluated. Oxidation of the oil blend was determined by peroxide value and rancimat test. Improved oxidative stability was observed for fish oil blended with butter. Unsalted and salted butters showed no difference in improvement of effect on oxidative stability of fish oil. No influence on oxidative stability for the fish oil was observed with butter oil, which was the oil fraction of butter. These studies suggested that the improved oxidative stability of fish oil-butter blend was due to the hydrophilic fraction of butter and that butter could improve the oxidative stability of polyunsaturated oils such as fish oil.

To observe the effects of supplemental dietary d-α-tocopherol in relation to dietary energy on growth and immune status in dairy calves, 32 newborn Holstein bull calves were assigned to 1 of 4 treatments for 5 wk in a 2 × 2 factorial, randomized complete block, split-plot design. Calves received moderate growth (MG) or low growth (LG) all-milk dietary treatments, formulated to support daily gains of 0.5 or 0.25 kg/d, respectively, per the dietary energy recommendation for milk-fed calves according to the National Research Council's Nutrient Requirements of Dairy Cattle. Calves in both groups were either injected i.m. with Vital E-A+D (injectable solution of vitamins E, A, and D) on d 1 and supplemented with Emcelle Tocopherol (micellized vitamin E) via milk daily (MG-S and LG-S), or were not supplemented (MG-C and LG-C) during the study period. Total weight gain of MG calves was greater than that of LG calves and tended to be greater in MG-S calves than in MG-C calves. Calves receiving vitamin supplementation demonstrated greater concentrations of plasma α-tocopherol, retinol, and 25-(OH)-vitamin D than did control calves, whereas MG calves demonstrated a lower concentration of plasma α-tocopherol than did LG calves. The apparent increased utilization of α-tocopherol by MG calves was accompanied by a rise in serum haptoglobin, a positive acute-phase protein and indicator of inflammation, especially in MG-C calves. Serum amyloid A, also a positive acute-phase protein, was not different among groups, but was elevated from baseline in all groups during wk 1 through 3. Plasma IgG1 concentrations were higher in MG-S and LG-S calves than in their nonsupplemented dietary counterparts, whereas plasma IgG2, IgA, and IgM concentrations were not different among groups. In summary, dietary supplementation of d-α-tocopherol improved plasma α-tocopherol status and tended to increase growth in calves fed for 0.5 kg of average daily gain. Vitamin supplementation ameliorated the rise of serum haptoglobin associated with acute inflammation in MG calves, and may have improved passive transfer of maternal antibody. These results indicate a role for α-tocopherol in prevention of proinflammatory state associated with greater dietary energy and onset of infectious disease.

Eighteen cows were challenged by intramammary infusion with Escherichia coli 727 to determine the effects of acute clinical mastitis on alpha-tocopherol concentrations in plasma and milk. Cows were fed diets supplemented with 1000 IU of vitamin E/d from calving through the experimental period. At challenge, geometric mean DIM was 33 d. Each mammary quarter was diagnosed with an IMI and clinical mastitis at 24 and 48 h after challenge. The alpha-tocopherol concentrations in milk from challenged quarters were approximately 60% greater by 24 and 48 h after challenge than concentrations at prechallenge and 168 h postchallenge. Plasma alpha-tocopherol concentrations did not change after intramammary challenge. The alpha-tocopherol in plasma and milk was correlated at 48 and 168 h postchallenge but not at prechallenge or 24 h postchallenge. Milk alpha-tocopherol and SCC were correlated positively across all sample periods. Milk fat and milk alpha-tocopherol concentrations were correlated at each sample period except 24 h postchallenge. Increases in milk alpha-tocopherol during clinical mastitis were not correlated to milk production, DMI, or BSA concentration in milk. Changes in milk alpha-tocopherol concentration during clinical mastitis were similar to the dynamics of milk SCC.

Milk samples with and without oxidized flavor were obtained from two different commercial dairy herds. Milk components that are important for the susceptibility of milk fat to spontaneous oxidation, (i.e., fatty acid composition and the concentrations of α-tocopherol, β -carotene, and ascorbic acid) were analyzed to describe the variation in the susceptibility of milk fat to oxidation in raw milk. The samples were also analyzed using dynamic headspace gas chromatography to determine volatile oxidation products, primarily straight-chain aldehydes. The results showed that milk samples exhibiting off-flavor had higher linoleic acid content in the neutral fat fraction. At one farm, the concentrations of both α-tocopherol and β -carotene were lower in samples that demonstrated off-flavor. At the other farm, this difference was not statistically significant. Milk with off-flavor also had significantly higher concentrations of hexanal. The data were also analyzed by principal component regression. The results from this analysis indicated that the causative factors for the oxidation were different for the two herds.

Nonlactating cows were fed diets containing 88% grass forage and 12% concentrate (DM basis). Starting 14 d prior to anticipated calving, the concentrate was changed to provide 0 or 200 g of supplemental fat and 0 or 890 IU of supplemental vitamin E daily. Following parturition, cows were fed for 14 d a 50% concentrate diet that provided the same amounts of supplemental fat and vitamin E that were fed during the dry period. Plasma was sampled and analyzed for alpha-tocopherol and beta-carotene. Supplemental dietary fat elevated plasma concentrations of both nutrients during the peripartum period. Supplemental dietary vitamin E elevated concentrations of alpha-tocopherol during that period. Dietary fat also increased concentrations of plasma cholesterol. When alpha-tocopherol and beta-carotene were expressed per unit of plasma cholesterol, fat supplementation did not affect concentrations. Dietary treatments did not influence concentrations of alpha-tocopherol in blood neutrophils and did not affect intracellular kill of bacteria by neutrophils. Essentially no beta-carotene was found in the neutrophils. For colostrum, dietary vitamin E increased concentrations of alpha-tocopherol and decreased concentrations of beta-carotene.

The effect of temperature and length of storage on the stability of alpha-tocopherol in UHT milk was studied by HPLC. The effect of water activity conditions during storage of milk powder on the stability of the same vitamin was also studied. Losses of alpha-tocopherol occurred in UHT milk after 1 mo of storage at 30 degrees C; losses increased as storage time increased. In general, when the storage temperature changed from 30 to 40 degrees C, decrease in alpha-tocopherol content was greater. Short periods of frozen storage of the UHT milk (up to 60 d) had no effect on alpha-tocopherol content. However, frozen storage from 4 to 8 mo produced losses in alpha-tocopherol. When water activity was increased, the alpha-tocopherol content in milk powder decreased significantly after 2 mo of storage at 20 degrees C.

Addition of safflower oil to a growth medium depressed the growth of mixed rumen bacteria above 200 mg/L and did not significantly increase bacteria, even at lower concentrations. However, when 10 mg/L of beta-carotene were added to 50 to 100 mg/L of safflower oil, bacterial growth was significantly increased. When more than 200 mg/L of safflower oil were present, beta-carotene markedly restored the growth capacity. alpha-Tocopherol was more effective than beta-carotene, although it inhibited growth at high concentrations. The combination of beta-carotene and alpha-tocopherol (each 5 mg/L) exerted partially additive effects. beta-Carotene plus alpha-tocopherol enhanced bacterial cell yield in the presence of safflower oil, caprate, stearate, or linoleate, suggesting that beta-carotene and alpha-tocopherol increase the utilization of fatty acids. beta-Carotene plus alpha-tocopherol also stimulated cellulose digestion in the presence of 100 mg/L of safflower oil, evidently through the increased growth of cellulolytic bacteria.

Holstein cows were fed 0 or 1000 IU/d of supplemental vitamin E during the dry period and injected with placebo or 3000 IU of vitamin E at 10 and 5 d prior to anticipated calving. Blood was collected at various times, starting at 60 d prepartum (dry off) and concluding 30 d postpartum, and separated into plasma, red blood cells, and neutrophils. Oral supplementation increased concentrations of alpha-tocopherol in plasma and red blood cells on 10 d, but not on 5 d prepartum. Injection of vitamin E increased alpha-tocopherol in plasma, red blood cells, and neutrophils at d 5 prior to and on the day of parturition. Concentrations of alpha-tocopherol and cholesterol in plasma were correlated, and both were at their nadir at parturition. Concentrations of alpha-tocopherol in plasma and red blood cells were correlated, but the correlation increased when plasma alpha-tocopherol was expressed per unit of cholesterol. alpha-Tocopherol in plasma and neutrophils had a low correlation. Injection of alpha-tocopherol increased its concentration in plasma, red blood cells, and neutrophils during the periparturient period. Concentration of alpha-tocopherol in plasma of periparturient cows may be limited by its low lipid content, and transport mechanisms for alpha-tocopherol may differ between red blood cells and neutrophils.

A soft physical process was used to extract and purified bovine milk fat globule membrane (MFGM) fractions on a pilot scale. Oil-in-water emulsions enriched with alpha-tocopherol and lycopene were then prepared and stabilized with the extracted MFGM fraction and conventional milk protein concentrates (i.e., whey proteins, caseinate). A protocol of in vitro digestion was set up to evaluate the bioaccessibility of the tocopherol and lycopene in the different emulsions. Bioaccessibility was defined as the capacity of liposoluble compounds to be transferred into mixed micelles formed during the digestion process. Results showed that the accumulation of the tocopherol and lycopene into mixed micelles in MFGM-stabilized emulsions was around 2-fold greater than in emulsions stabilized with conventional milk proteins. This result confirms the potential use of MFGM-enriched ingredients as delivery systems of liposoluble nutrients in food formulations.

The purpose of this study was to compare the bioavailability of dl-alpha-tocopheryl acetate and d-alpha-tocopheryl succinate when administered to sheep in a single oral dose weekly. The sheep, five per treatment, were given a basal diet without vitamin E supplement (control) or basal diet with weekly administration of 2225 IU of dl-alpha-tocopheryl acetate, 2225 IU of d-alpha-tocopheryl succinate, or 6675 IU of d-alpha-tocopheryl succinate. Increases in plasma alpha-tocopherol concentration levels over the 3-wk period of study were determined and compared. The greater availability of dl-alpha-tocopheryl acetate was indicated by the significantly higher peak plasma alpha-tocopherol concentrations and the greater area under the curve produced by administration of the acetate than the succinate esters at the same dosage. Reported data on plasma alpha-tocopherol concentrations suggest that bioavailability in sheep of d-alpha-tocopheryl succinate versus dl-alpha-tocopheryl acetate is 3:1.

Our experiment was carried out with Holstein cows in midlactation to assess effects of feeding 0 or 40g formalin-treated canola oil as Protec ® in combination with 0 or 400 IU of vitamin E/kg of DM on fatty acid composition of milk fat, vitamin E content, and oxidative stability of milk stored under refrigeration. The effect of treated canola oil on fatty acid composition of milk fat was typical of feeding a C 18 -rich untreated oil, i.e., a marked increase in the proportion of stearic, oleic, linoleic and linolenic acids and a concomitant decrease in C 6 to C 16 fatty acids. High vitamin E diet increased vitamin E content in milk fat to 40 to 50μg/g, i.e., similar to that reported for cows on pasture. There was no significant dietary Protec ® × dietary vitamin E interaction. Measurement of thiobarbituric-acid-reactive substances showed that milk of cows fed high vitamin E was stable at 5°C for 5 d under .1ppm Cu ++ contamination. At 1ppm Cu ++ contamination, storage time showed an inverse relationship to the apparent concentration of thiobarbituric-acid-reactive substances. This artifact arises from absorption of Cu ++ by milk proteins. It was established that the unsaturated fatty acids of canola oil in Protec ® were not well protected from hydrogenation in rumen and that thiobarbituric acid data should be interpreted with caution.

Four experiments were carried out with Holstein cows in early lactation to assess the effect of feeding, 0, 50, and 400 IU of vitamin E/kg of DM on transfer of vitamin E to milk fat. The effects of adding 50 g of calcium salts of fatty acids/kg of DM on DM intake, milk production, and milk quality also were studied. Feeding of 10 g of vitamin E (dl-α-tocopheryl acetate) per cow daily for 4 wk prepartum and about 8 g daily (400 IU/kg of dietary DM) for wk 1 to 8 of lactation maintained 40 to 54 μg of vitamin E/g of milk fat. Transfer of vitamin E to milk in early lactation was impaired, and the causes for this are discussed. Feeding calcium salts of fatty acids had a tendency to reduce DM intake and decreased protein and lactose content of milk in one experiment. This treatment had little effect on fatty acid composition and vitamin E content of milk fat in early lactation, but after peak production it increased oleic and linoleic acids in milk fat.

The effectiveness of added antioxidants against oxidation off-flavor development in light-exposed milk was evaluated using sensory and chemical analysis. Sensory testing for similarity showed no perceivable difference between control milk and milk with added (1) 0.05% alpha-tocopherol (TOC) and (2) 0.025% alpha-tocopherol and 0.025% ascorbic acid (TOC/ASC), but did demonstrate a perceivable difference when adding (3) 0.05% ascorbic acid (ASC) alone. Subsequently, sensory testing for difference showed a significant difference in oxidation off-flavor between light-exposed control milk and light-exposed milk with added TOC/ASC, whereas milk fortified with TOC was not different from control. Gas chromatography-olfactometry showed that more aroma-active flavor compounds were observed in light-exposed milk treated with TOC and TOC/ASC than light-exposed milk with no added antioxidants. The thiobarbituric acid reactive substances (TBARS) test verified chemically the extent of oxidation in control and antioxidant-treated milk samples. Milk that was exposed to light for 10 h showed a significantly higher TBARS value (0.92 +/- 0.09 mg/kg) than milk that was protected from light (0.59 +/- 0.184 mg/kg), or milk that was treated with TOC/ASC (0.26 +/- 0.092 mg/kg). Direct addition of low levels of antioxidants (TOC/ASC) to milk protected its flavor over 10 h of light exposed storage.

Diets with different fat treatments and with 25, 125, or 250 IU of supplemental vitamin E (all-rac alpha-tocopheryl acetate)/kg of dry matter (DM) were fed for 28 d to midlactation Holstein cows to determine factors affecting concentrations of alpha-tocopherol in milk. Diets contained no supplemental fat or 2.25% added fat from roasted soybeans or tallow. Vitamin E treatment had no effects on production, but fat supplementation increased milk yield (37.2 vs. 35.1 kg/d). Cows fed RSB ate more DM (24.0 vs. 21.9 kg/d) and produced more milk fat than cows fed tallow. Supplemental fat increased plasma concentrations of alpha-tocopherol and cholesterol. Increased intake of alpha-tocopherol linearly increased concentrations of alpha-tocopherol in plasma but the rate of increase was 1.9 times greater when fat was fed. Plasma alpha-tocopherol concentrations were linearly related to concentrations in milk, but a change in plasma alpha-tocopherol resulted in a smaller change in milk alpha-tocopherol when fat was fed than when it was not. Fat treatment did not affect plasma alpha-tocopherol expressed relative to plasma cholesterol (mg alpha-tocopherol/g cholesterol) or relationships between plasma alpha-tocopherol/g of cholesterol and milk alpha-tocopherol. These data suggest that concentrations of alpha-tocopherol in milk are a function of the alpha-tocopherol enrichment of the plasma lipid fraction and enrichment of that fraction is saturable.

Relationships among dietary roasted whole soybeans (RSB), milk fatty acid profile, and the development of spontaneous oxidized flavor of milk were investigated by using 20 commercial dairy herds. Diets contained 0 to 15.3% of dry matter as RSB. Concentrations of dietary RSB were correlated positively with concentrations of C18:2 and C18:3 in milk fat. Concentrations of alpha-tocopherol, beta-carotene, and ascorbic acid in milk decreased from 0 to 3 d of storage (4 degrees C), and oxidized flavor in milk increased linearly between 0 and 8 d of storage. Milk fatty acid profile did not change during storage. The development of oxidized flavor at 8 d postsampling was correlated (r) with increased concentrations in milk fat of C18:2 (0.49), C18:3 (0.55), total polyunsaturated milk fatty acids (0.50), and dietary concentrations of RSB (0.38). Multiple regression was used to quantify relationships between variables and oxidized flavor (samples stored 8 d). All significant models included milk concentrations of Cu and dehydroascorbic acid. Concentrations of C18:2, C18:3, or total polyunsaturated fatty acids in milk fat, or dietary RSB concentrations, and interactions of those variables with Cu were included in individual models. Milk with high concentrations of polyunsaturated fatty acids and Cu were most susceptible to oxidation. Feeding RSB increased polyunsaturated fatty acid concentrations in milk fat, which increased the likelihood of oxidized flavor, especially when milk had high concentrations of Cu.

We tested the hypothesis that the incidence of retained fetal membranes could be reduced by limiting oxidative stress. Sixty-four primigravid heifers (56 Holstein and 8 Jersey) and 80 multiparous cows (64 Holstein and 16 Jersey) were used. A combination of vitamin E or Zn and Fe was fed in a 2 x 2 x 2 factorial arrangement during the last 42 d prepartum. Amounts of supplements per animal were 1000 IU of vitamin E (d, l alpha-tocopheryl acetate), 0.8 g of Zn (Zn-Met and ZnSO4), and 12 g of Fe (FeSO4.7H2O) for Holsteins and 9 g for Jerseys. Neither vitamin E nor Zn directly affected the incidence of retained fetal membranes, but plasma alpha-tocopherol was lower when fetal membranes were retained > 12 h or when vitamin E was not supplemented. Iron had no direct negative effects on reproductive performance, but cows receiving additional Fe had lower unsaturated iron-binding capacity, which, in turn, was also lower in cows that retained fetal membranes. Days to first observed estrus were reduced by supplementation with either vitamin E or Zn. Vitamin E reduced days to first artificial insemination (AI) and tended to reduce days open. Supplemental Zn tended to reduce days to first AI but did not affect days open. Milk production during the first 12 wk and AI per conception were not affected by supplementation with either vitamin E or Zn. Both vitamin E and Zn reduced days to first observed estrus, indicating improved reproductive health during the early postpartum period.

Long-term effects of the inclusion of cottonseed meal in the diet on hematological and tissue parameters of Holstein bulls were investigated. Twenty-four Holstein bulls that were approximately 6 mo of age received the following treatments for 10 mo: 1) soybean meal plus 30 IU of vitamin E/kg, 2) cottonseed meal plus 30 IU of vitamin E/kg, and 3) cottonseed meal plus 4000 IU of vitamin E/d per bull. Treatments 2 and 3 were formulated to supply 14 mg of free gossypol/kg of body weight per d. Average daily gain, total gain, and final body weights were not affected by treatment. The osmotic fragility of erythrocytes was greater during all collection periods for bulls on treatments 2 and 3 than for bulls on treatment 1. The inclusion of 4000 IU of vitamin E/d per bull did not reduce the increase in the osmotic fragility of erythrocytes that was caused by gossypol. Bulls on treatment 3 had higher plasma alpha-tocopherol concentrations than did bulls on treatments 1 and 2. Vitamin E supplementation did not affect gossypol concentrations in plasma or tissue. The highest gossypol concentrations were found in the liver followed by the heart and testis. In vitro lipid peroxidation of tissue indicated that gossypol acts as an antioxidant in lipid peroxidation systems, and its role as an antioxidant may be dependent on dose or tissue. Cottonseed meal in the diets of bulls did not affect growth or vitamin E status.

The effects of daily supplementation of 1000 IU of d- α - or dl- α -tocopherol acetate to Holstein cows from drying off to 8 wk after calving were studied 1) to compare the bioavailability of d- α - and dl- α -tocopherol acetate by monitoring vitamin E concentrations in plasma, red blood cells, and neutrophils and 2) to determine the effect of d- α - and dl- α -tocopherol acetate supplementation on O 2 − and H 2 O 2 release by neutrophils. Supplementation with d- α - or dl- α -tocopherol acetate increased vitamin E concentrations in blood plasma, red blood cells, and neutrophils; the d- α form was more effective than was the dl- α form. Supplementation with d- α - or dl- α -tocopherol acetate had no effect on the release of O 2 − and H 2 O 2 by neutrophils, suggesting no harmful effects on surrounding tissues from oxygen-free radicals produced by neutrophils.

Five sheep, with a mean BW of 45 kg, were given a single i.m. injection (600 IU) of dl-alpha-tocopherol acetate. Plasma concentration of alpha-tocopherol was best fitted to a single-compartment model. Two successive absorption processes were selected. The individual pharmacokinetic parameters were absorption rate constant, Ka1 = 0.29 +/- 0.02/h; the second absorption rate constant, Ka2 = 0.03 +/- 0.002/h; elimination half-life = 42.40 +/- 1.70/h; mean residence time = 46 +/- 0.92 h; and area under the curve = 290 +/- 10.77 micrograms/h per ml. During the first absorption process, elimination half-life was 2.46 +/- 0.22 h, and the second elimination half-life was 21.20 +/- 1.72 h. The peak concentration of vitamin E plasma (4.78 +/- 0.23 micrograms/ml) was observed at 14.6 +/- 4.08 h after i.m. injection. The increase in vitamin E concentration occurred because of gradual hepatic hydrolysis of the absorbed acetylated tocopherol.

D-alpha-Tocopherol in an emulsible base was administered i.p. to four groups of five sheep each at doses of 0, 1250, 2500, and 5000 IU. Blood was sampled regularly until slaughter at 7 d after administration. Plasma and tissue concentrations of D-alpha-tocopherol were measured by HPLC. Pharmacokinetic analysis of plasma concentrations, for the three tested doses, showed an absence of significant difference for lag time to absorption (.9 to 2.5 h), half-time of absorption (15 to 30 h), plasma half-life (31 to 42 h), and time of maximal concentration (18 to 31 h). In contrast, dose had a significant effect on area under the tocopherol plasma curve and on the maximal concentration. For both parameters, statistical evidence indicated nonlinearity for disposition of D-alpha-tocopherol, but without biological significance; by 7 d after dosing, amounts of residue of tocopherol were highest in the pancreas and adrenal glands (approximately 65 and 47 micrograms/g, respectively, for the 5000 IU dose) and lowest in neck muscle (approximately 4 micrograms/g for the 5000 IU dose). Kidney had an intermediate level of tocopherol. The intraperitoneal route is an efficient route for tocopherol administration in sheep.

Blood and hepatic tocopherol concentration following i.m. injection or oral supplementation was studied in nonlactating dairy cows and pregnant beef heifers, respectively. In Experiment 1, cows received a single i.m. injection of either 4500 IU of d-alpha-tocopherol or 4500 or 7500 IU of dl-alpha-tocopheryl acetate. Plasma and liver tocopherol concentrations were recorded before and up to 4 wk postinjection. In Experiment 2, heifers received either 0, 1000, 2000, or 4000 IU of dl-alpha-tocopheryl acetate daily in the ration for 3 wk. Serum and hepatic tocopherol concentrations were measured before, during, and 3 wk following supplementation. In Experiment 1, level of tocopheryl acetate given influenced plasma and hepatic tocopherol concentrations. Plasma alpha-tocopherol concentration was greater in cows given unesterified tocopherol than an equivalent amount of tocopherol acetate. There was a quadratic relationship between plasma and hepatic tocopherol concentration. In Experiment 2, increasing dietary intake of dl-alpha-tocopheryl acetate failed to increase markedly tocopherol levels in serum or liver. There was no relationship between serum and hepatic tocopherol concentrations. Prior to the trials, serum levels in Experiment 2 were less than plasma levels in Experiment 1, but hepatic levels were greater. Physiological state can influence the relation between circulating and stored reserves of tocopherol, and circulating tocopherol concentration may not be a good indicator of its reserves.

Nine well-managed dairy herds were monitored for 1 yr to determine if bulk tank SCC and rate of clinical mastitis were associated with dietary and plasma Se and vitamin E status. Intakes of Se and vitamin E were 1 to 16 mg/d and 100 to 900 mg/d, respectively. Plasma Se concentrations were correlated positively with intakes of Se below 5 mg/d but were independent of Se intakes above 5 mg/d. Feeding vitamin E increased plasma concentrations of tocopherol, but the influence of dietary vitamin E on plasma concentrations was four times greater for dry cows than for lactating cows probably due to secretion of tocopherol into colostrum and milk. Bulk tank SCC averaged 5.4 log10/ml and decreased significantly as Se concentration in plasma increased. Plasma glutathione peroxidase was correlated positively to Se intake but negatively to SCC. Rate of clinical mastitis was negatively related to plasma Se concentration and concentration of vitamin E in the diet. An apparent interaction between dietary Se and vitamin E was evident since herds fed high amounts of Se tended to have high rates of clinical mastitis, but not if high amounts of vitamin E were fed. These data confirm earlier findings that Se and vitamin E status of dairy cows are related to mammary gland health.

The purpose was to determine if cows fed corn silage during gestation have calves with low serum tocopherol and high erythrocyte hemolytic rates. Ten cows were fed hay, six fed corn silage with one vitamin E injection, and six fed corn silage with no injection beginning with the 6th mo of gestation. Hay intakes were adjusted to equalize intakes of dry matter. Analysis of tocopherol isomers was by reverse phase, high performance liquid chromatography. Alpha-tocopherol and potassium were lower for hay-fed cows than for cows fed predominantly corn silage, but creatinine phosphokinase, glutamic-oxaloacetic transaminase, and glucose were higher. Calves from hay-fed cows had lower alpha-tocopherol and higher glutamic-oxaloacetic transaminase. No consistent histopathological changes of muscle tissue were seen. Erythrocyte hemolytic rates were low. Serum vitamin E of cows may change during gestation because of type of forage fed. Specific enzyme changes may give an early indication of a change of tocopherol status of cattle.

Two trials were carried out to evaluate the bioavailability of dl-α-tocopherol and dl-α-tocopherol acetate administered to sheep and cattle in a single oral dose. In the first trial, two groups of five sheep were used. They received 100 mg/kg body weight of either dl-α-tocopherol or its acetylated form. The blood plasma α-tocopherol tolerance curve area was higher in the dl-α-tocopherol group than in its ester form. The time to reach maximum plasma α-tocopherol concentration was less in the dl-α-tocopherol group than in its ester form. In a second trial, four heifers received the two forms (50 mg/kg body weight) in rotation after an appropriate washing period between the two dosings. Again, plasma tolerance curve area was greater in the cattle following administration of dl-α-tocopherol than its acetylated form. EEA Colonia Benitez Fil: Hidiroglou, Nick N. University of Florida. Animal Science Department; Estados Unidos Fil: McDowell, Lee Russell. University of Florida. Animal Science Department; Estados Unidos Fil: Balbuena, Osvaldo. University of Florida. Animal Science Department; Estados Unidos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; Argentina.

Twelve to fifteen commercial samples of sweet- and acid-type dry whey were analyzed each quarter for 12 vitamins and 14 minerals during a year. Mean vitamin contents for sweet- and acid-type per 100g were vitamin A 136 and 107 IU, C 1.41 and .33mg, B 6 .59 and .62mg, B 12 2.4 and 2.5 μ g, tocopherol .063 and .071mg, thiamin .51 and .49mg, riboflavin 2.14 and 1.85mg, pantothenic acid 11.5 and 11.4mg, biotin 43.0 and 35.0 μ g, niacin 1.30 and 1.16mg, folacin .0116 and .0332mg, and choline 104 and 101mg. Storage for 22 mo resulted in an average decrease of 70.9% for vitamin A, 34.8% for B 6 , and 34.3% for biotin. The mineral values for the sweet- and acid-type dry wheys have means per 100g of: calcium 878 and 2,404mg, phosphorus 1,096 and 1,588mg, sodium 1,287 and 1,087mg, potassium 1,855 and 1,915mg, magnesium 178 and 224mg, zinc 2.1 and 8.1mg, iron .9 and 1.3mg. Copper was 2.8 and 5.3ppm, iodine 6.79 and 8.64ppm, lead 1.15 and 1.68ppm, mercury .02 and .03ppm, selenium .064 and .034ppm, cadmium .11 and .14ppm, and arsenic .77 and .59ppm; calories (Kcal/g) were 3.71 and 3.86.

Factors affecting spontaneous oxidation in 1198 raw milk samples collected from 137 herds were determined. Milk was examined organoleptically for oxidized flavor 48h after collection on a 0 (none) to 4 (pronounced) scale. The mean concentration of copper was 48 μ g/kg and of tocopherol 25.6 μ g/kg lipid. Copper and tocopherol concentrations were correlated with oxidized flavor score and together accounted for 15.1% of its variation. Variables of herd were breed of cow, age of cow, and percent of herd in first 60, second 60, and more than 120 days of lactation. No correlations were significant between breed or age of cow and oxidized flavor score. The percent of herd in the first 60 days of lactation was correlated with oxidized flavor score but accounted for only 3.9% of the variability. Variables of management were age, type, and amount of hay fed, type and amount of concentrate fed, and production of milk and milk fat. No correlations between type or amount of feed and oxidized flavor score were significant. Production both of milk and milk fat was correlated with oxidized flavor score but accounted for only .40 and .03% of the variability.

An experiment was conducted to study the effect of dietary to copherol and P on the serum cholesterol, muscle cholesterol, serum vitamin E, and mineral composition of nonruminating calves. A milk replacer diet was supplemented with a high monosodium phosphate (18 g· calf −1 ·d −1 ) and vitamin E (as coated dl-alpha-tocopheryl acetate 100 IU· calf −1 ·d −1 ) and was fed to Holstein bull calves (n = 15) for 2 wk prior to slaughter. This significantly decreased serum and muscle cholesterol; increased vitamin E, P, Ca in serum; and simultaneously reduced serum Na content 15% when compared with that of the control group (n = 15). There were no treatment effects on serum K, Mg, packed cell volume, and hemoglobin values. These findings may be beneficial in regulating the incidence of coronary heart disease if dietary tocopherol and P could cause the same effect in humans.

High fat diets +/- 1 g alpha-tocopheryl acetate per head per day were fed to 28 cows for 4 mo to determine whether dietary fat increases dietary requirement for vitamin E. Tocopherol supplementation did not affect milk production or composition. After 4 mo there was no difference between treatment groups for oxidative stability (thiobarbituric acid test) of milk stored for 5 days with .1 ppm added copper, but milk of supplemented cows was more stable when 1 ppm copper was added. Oxidative stability was normal in the unsupplemented group. Tocopherol concentration of blood plasma increased and selenium concentration decreased with tocopherol supplementation; activity of glutathione peroxidase was lower in plasma, whole blood, and erythrocytes of the supplemented group. Tissue integrity was unchanged by tocopherol supplementation, as estimated by erythrocyte hemolytic resistance and activities of lactic dehydrogenase and glutamic oxalacetic transaminase in blood serum. Clearance of bromosulphthalein from blood plasma was less for cows fed fat and supplemented with tocopherol than for control cows fed neither fat nor vitamin E. No indication of impaired vitamin E status was observed when 4% stabilized fat was added to the diet.

Twenty-eight Holstein heifer calves were allotted at birth to one of four treatments: 1) 0 mg, 2) 1,400 mg, or 3) 2,800 mg of dl-alpha-tocopherol acetate given orally at weekly intervals, or 4) 1,400 IU of dl-alpha-tocopherol weekly by intramuscular injection in order for us to study their performance and metabolic profile. Calves were fed milk at 8% of birth weight until they were weaned at 6 wk of age and fed a complete calf starter ad libitum from birth. Calves were on experiment for 12 wk. There were no significant differences in weekly weight gains, starter consumption, and fecal scores among treatments. However, there was a trend toward greater starter consumption and weight gains in supplemental calves. Serum alpha-tocopherol concentration measured after 7 d of each administration was significantly higher at wk 4 in calves given the high oral supplementation and at wk 2, 4, 6, and 8 higher in injected calves than in unsupplemented calves. Creatine kinase activity was higher in unsupplemented calves and negatively correlated with serum alpha-tocopherol until wk 8, suggesting preclinical muscular dystrophy. Alkaline phosphatase activity was higher with the high oral supplementation. Serum carbon dioxide values showed a trend toward positive correlation with those for serum tocopherol; however, the values were within normal range. There were no significant differences in creatinine, glucose, phosphorus, calcium, urea nitrogen, chloride, sodium, potassium, albumin, and total protein among treatments. Serum glucose was higher in all calves at wk 10 and 12 than at wk 4, 6, and 8. Calves may not get enough vitamin E with conventional calf starters, and supplementation may be essential to obtain maximum performance.

Summary Gross and microscopic lesions were demonstrated in the cardiac and skeletal muscles of calves fed corn oil or lard filled milk. Such lesions were also found in animals receiving a similar ration containing butter oil, which had been prepared from oxidized butter. Both oral and intramuscular supplementation of the corn oil and lard filled milk diets with high levels of tocopherol prevented the development of muscular involvement during the course of the experiment. No evidence of muscular involvement was encountered in calves fed a low-fat, tocopherol-poor ration for periods as long as 5.6 mo. The influence of certain fats in the diet on the production of so-called vitamin E deficiency lesions in cattle is discussed. The microscopic lesions in cardiac and skeletal muscles are characterized in detail. In general, these lesions were typical of those described previously as occurring in white muscle disease or nutritional muscular dystrophy. Necrospy findings, other than muscular lesions, are also presented. Marked changes occurred in the electrocardiographic pattern of subjects in the corn oil filled milk group. The factor(s) responsible for these gross alterations could not be ascertained from the available data. The determination of creatinuria ratios did not provide a means of following the development of muscular involvement in calves.

Summary In investigating the role of tocopherol as an antioxidant in milk, intravenous injection of tocopherol was used as an approach that would give more complete control of variables than can be obtained in feeding trials. Injection of 7g of dl-α-tocopherol or 10g of dl-α-tocopherol acetate in unemulsified form gave negligible increases in tocopherol and oxidative stability of milk, but as little as 1.5g of either tocopherol injected in emulsified form caused marked increases in milk tocopherol and oxidative stability. When injected as emulsions, tocopherol acetate gave greater response than tocopherol. For individual cows, correlations between milk tocopherol and oxidative stability were highly significant. In comparing milks from different cows, however, the tocopherol level did not provide a reliable indication of susceptibility to oxidized flavor. In an experiment in which the milk lipids were fractionated by a churning procedure, changes in oxidative stability of the milk after tocopherol acetate injections correlated with tocopherol in the membrane lipids (from buttermilk) more closely than with that inside the fat globules (butteroil).