Effect of vitamin E supplementation to ewes in late pregnancy on the rate of stillborn lambs

Causes of abortion in Iranian sheep flocks and associated risk factors

Abortion is a major issue in sheep husbandry. It can result in significant economic losses and a severe public health risk. This survey assessed the infectious and non-infectious causes of abortion in Iranian sheep flocks and determined the main risk factors. In this cross-sectional survey, causes of abortion were evaluated in 757 sheep flocks, and risk factors were analysed. A checklist containing general animal information for each abortion outbreak evaluated was filled in. Data were analysed using univariate tests and multivariable binary logistic regression analysis. In this sense, parity, gestational age of the aborted fetus, vaccination protocol, mineral supplementation and history of stillbirth showed significant associations with abortion. Infectious agents such as Coxiella burnetti (22.7%), Chlamydia abortus (12.3%) and Brucella melitensis (10.4%) were the most frequently isolated in the investigated flocks, with more than 2% of abortion rates. On the other hand, non-infectious agents such as trauma, pregnancy toxaemia and vitamin E/Se deficiency were involved in those flocks with low abortion rates (less than 10%). Results revealed multiple causes of abortion outbreaks among Iranian sheep flocks, which need careful investigation to identify possible aetiology and risk factors. Further studies are necessary to evaluate if these factors are similar to other countries in the same region.

Redox Status of Pregnant Ewes after Vaccination against Clostridial Diseases

The redox status shortly after the vaccination of pregnant ewes is rather unexploited. Thus, the present study was designed to evaluate the fluctuation of redox status after the administration of the annual booster dose of a polyvalent clostridial vaccine in pregnant ewes, 3 to 4 weeks before lambing, with or without a simultaneous injection of Vit E/Se. In total, 24 pregnant Lacaune ewes 3–4 weeks before lambing were randomly allocated into four equal groups: the V (vaccinated with a polyvalent clostridial vaccine), VE (vaccinated and injected IM with Vit E/Se), E (injected IM with Vit E and Se), and C (neither vaccinated nor injected with Vit E/Se). The study period lasted for 21 days, starting on the day of administration. Four redox biomarkers, the antioxidant capacity (TAC), the thiobarbituric acid reactive substances (TBARS), the reduced glutathione (GSH), and the catalase (CAT) were evaluated in blood samples collected from all ewes before the injections (0 h) and then at 12 (12 h), 24 (D1), and 48 h (D2), and thereafter on days 4 (D4), 6 (D6), 10 (D10), 14 (D14), and 21 (D21). The results reveal that the TAC was the only biomarker evaluated that was significantly affected by group and significantly lower in vaccinated animals (V and VE groups) compared to non-vaccinated (E and C groups). The absence of an increase in the TBARS values after vaccination in groups V and VE indicates the absence of significant oxidative stress. Overall, it can be assumed that annual booster immunizations against clostridial diseases do not impose acute oxidative stress on pregnant ewes in the last month of pregnancy.

The effect of vitamin E treatment on selected immune and oxidative parameters in Kivircik ewes suffering from transport stress

The study aimed to investigate the effects of vitamin E injection for the prevention of transport stress on ewes. Kivircik ewes (2-3 years old, n = 24) were randomly separated into three groups; G1 (Control) and G2 treated with 14 ml. saline as the placebo, G3 treated with 2100 IU/ind. DL-alpha-tocopherol acetate prior to transport. G2 and G3 were transported at 80 km/h for 4 h on a truck. Serum samples were obtained before (T0) and after (T1) transport. Serum cortisol, catalase, IgG, ceruloplasmin, C-reactive protein, complement component 4, interleukin-1 beta, tumour necrosis factor-alpha, glutathione peroxidase (GPx), superoxide dismutase, malondialdehyde analyses performed by ELISA, and serum alpha-tocopherol concentrations were evaluated by HPLC-UV. Wilcoxon and Kruskal-Wallis tests were used for statistical assessments (p < 0.05). Alpha-tocopherol concentrations were founded 1.22 ± 0.82, 0.27 ± 0.14 and 0.14 ± 0.07 µmol/L, respectively, in G1, G2 and G3 at T1. Alpha-tocopherol concentration decreased significantly in G2 between T0 and T1. GPx concentrations were increased twofold in G2 and G3 between T0 and T1 (p < 0.01). As a result, G2 alpha-tocopherol concentrations decreased but, the stress and oxidative parameters tested in this study were not affected by treating 2100 IU/ind. DL-alpha-tocopherol acetate before transport.

Vitamin E and Selenium Treatment Alleviates Saline Environment-Induced Oxidative Stress through Enhanced Antioxidants and Growth Performance in Suckling Kids of Beetal Goats

Salinity is a worldwide, threatening problem affecting socioeconomic status globally. Saline land comprises salt content in soil, plants, and drinking water. Livestock farming is the worthy option for proper utilization of saline land in a cost-effective approach. Animals reared on this land experience a variety of stresses. Such stresses promote oxidative stress and reduced animal performance. The purpose of this study was to investigate the antioxidative function of vitamin E and selenium (Se) on pregnant/nonpregnant animals reared on the saline environment. A total of 36 multiparous pregnant (n = 18) and nonpregnant (n = 18) goats weighing about 38-45 (average 41.5) kg were equally divided into control and supplemented groups. The experiment lasted from 120 days of gestation to 15 days after parturition for pregnant goats and 0 to 45 days for nonpregnant cyclic goats (>50 days post-kidding). The supplemented group was administered vitamin E (1000 mg/kg BW) and selenium (3 mg/50 kg BW), while the control group was kept on normal saline (0.9% NaCl) with the same route 15 days apart. The blood samples were collected with 15 days apart during the entire experimental period of 45 days and subjected to assessment of enzymatic/nonenzymatic antioxidants, hydrolytic enzymes, oxidants, stress metabolic biomarkers, Se, and progesterone concentration of (pregnant) animals. Results revealed that vitamin E and Se supplementation significantly enhanced the activity of enzymatic (catalase and peroxidase) and nonenzymatic antioxidants such as total phenolic/flavonoid content and vitamin C and increased blood plasma level of Se concentration in comparison with the control group (P < 0.01). Exposure to antioxidant supplementation mitigated lipid peroxidation and enhanced progesterone level and total antioxidant capacity (P < 0.01) as compared to the control group in pregnant goats. Administration of vitamin E and selenium promoted kid survival rate (100%) along with increased initial birth weight, daily average weight gain, and total weight gain in comparison with the control group. Besides, the twinning rate and sex ratio were also recorded in pregnant animals. It is concluded that vitamin E and Se supplementation ameliorated salinity-induced oxidative stress, improved antioxidant status, and enhanced reproductive and growth performance of suckling kids reared on saline land.

Effect of increasing dosage of a multi-mineral-vitamin supplement on productive performance and blood minerals of fattening male Ghezel × Afshar lambs

This study was conducted to evaluate the effects of supplementation with different levels of mineral-vitamin supplement (MVS) on performance and health of fattening lambs. Thirty-nine fattening male Ghezel× Afshar lambs (averaging body weight 31.02 ± 3.46 kg) were used in a completely randomized design for a period of 84 days. Treatments consisted of 0 (CON), 15 (MVS15), or 30 (MVS30) g/day of MVS mixed into the concentrate. The results showed that inclusion of MVS in the ration linearly enhanced body weight (BW) on day 29 (P < 0.002), 45 (P = 0.05), and 70 (P < 0.002). Dry matter intake (DMI) was increased linearly (P < 0.02) and quadratically (P < 0.001) with increasing supplement between days 58 and 70. Overall DMI tended (P = 0.1) to be greater for the MVS 30 treatment. Total average daily gain (ADG), ADG between days 16 and 29, days 58 and 70, total gain: feed ratio, gain: feed ratio between days 16-29 and days 58-70 linearly increased with increasing amount of MVS in the ration (P < 0.01). The days with loose fecal scores were not affected by treatments (P > 0.05). There was a linear and quadratic (P < 0.01) effect on serum Ca concentration. Phosphorus concentration tended to quadratically increase (P = 0.06) with MVS. Blood serum Zn increased linearly (P = 0.01) with increasing level of MVS. Collectively, the results showed that, under the conditions of the current experiment, MVS addition to ration improved performance of fattening lambs.

Practical implications of mineral and vitamin imbalance in grazing sheep

Rapid progress in research on mineral functions in biological systems over the past 20 years has provided new and unexplored implications for health and production in grazing livestock. The strong interaction among calcium (Ca), magnesium (Mg), phosphorus (P), sodium (Na), potassium (K) and vitamin D influences the absorption, utilisation and status of these nutrients, particularly Ca and Mg. An imbalanced intake of Ca, Mg, P, Na, K and vitamin D is common in ruminants grazing pastures and vegetative crops. The interaction may modify susceptibility to clinical hypocalcaemia, hypomagnesaemia and pregnancy toxaemia, or to subclinical and chronic deficiencies of Ca, Mg and Na. However, hypocalcaemia is also associated with endocrine failure. Whether this failure is susceptible to nutritional modulation or even whether supplements of Ca, Mg, Na and vitamin D reduce or exacerbate the risk of metabolic disease in sheep is unclear. Selenium, manganese, zinc, copper, sulfur, vitamin E and vitamin A play synergistic roles in the antioxidant defence mechanism and modulate the consequences of oxidative stress. In extensive grazing systems combined low intakes of these antioxidants are not unusual, particularly in seasonally dry environments and at a time coinciding with the increased oxidative stress that naturally occurs through the reproductive cycle. This oxidative stress is accentuated by heat stress and parasite infection. Oxidative stress in the short-term influences growth, reproduction, offspring survival and health. Long-term, oxidative damage to embryo DNA and changes in RNA expression, may influence lifetime performance of offspring. The high cost of providing mineral supplements to grazing sheep is a deterrence to addressing the implications of multiple mineral deficiencies. New herbaceous and shrub options to increase the botanical and nutritional diversity within pasture and crop-grazing systems may allow livestock to select a heterogeneous diet providing a more balanced mineral intake.

Invited review: impact of specific nutrient interventions during mid-to-late gestation on physiological traits important for survival of multiple-born lambs

To improve production efficiency, the sheep meat industry has increased flock prolificacy. However, multiple-born lambs have lower birth weights, increased mortality and reduced growth rate compared with single-born lambs. Lamb mortality is a major issue for livestock farming globally and solutions are required to increase survival to realise the value of increased flock fecundity. Nutrition during gestation can influence maternal-foetal placental nutrient transfer and thus foetal growth and organ/tissue development, as well as improve postnatal productivity. This review covers the challenges and opportunities associated with increased prolificacy, highlights gaps in our knowledge and identifies some opportunities for how targeted intervention with specific nutrients during mid-to-late pregnancy may influence lamb survival and productivity with a specific focus on pasture-based systems. This time frame was selected as intervention strategies in short-time windows post-pregnancy scanning and before lambing to improve lamb survival in high-risk groups (e.g. triplets) are likely to be the most practical and economically feasible options for pasture-based extensive farming systems.