Effects of dietary iodine and selenium on nutrient digestibility, serum thyroid hormones, and antioxidant status of Liaoning cashmere goats

Combined Supplementation of Two Selenium Forms (Organic and Inorganic) and Iodine in Dairy Cows' Diet to Obtain Enriched Milk, Cheese, and Yogurt

This study evaluated the effects of dietary supplementation in dairy cows with two Se forms (organic and inorganic) and I at the maximum levels permitted in the European Union, with the aim to obtain naturally enriched milk and derived products. A total of 20 Holstein Friesian cows in lactation were fed 2 diets for 64 days: a control diet with a supply of 0.57 mg of inorganic Se and 0.57 mg of I per kg of ration in dry matter (DM), and an experimental diet (SeI) with a supply of 0.34 mg of inorganic Se, 0.23 mg of organic Se, and 5.68 mg of I per kg of ration in DM. The SeI diet did not modify the performance or, in general, the metabolic profile of cows. Se and I levels in milk were affected by diet type and time of measurement (p < 0.01). Thus, a marked increase of both microminerals was evident between the beginning and the end of the test, when the SeI diet was administered. For Se, this increase ranged from 1.95 to 3.29 μg/100 g of milk; and for I, from 19.69 to 110.06 μg/100 g of milk. The SeI diet increased (p < 0.01) the Se and I content in the cheese, reaching levels of 16.4 μg/100 g for Se and 269.7 μg/100 g for I. An increase in I was observed in yogurt from the SeI diet (p < 0.001). The supplementation of two forms of Se and I in the cows' ration, at the levels evaluated, produced milk and dairy products enriched in these microelements without altering their quality parameters. However, a responsible intake of these products is necessary to avoid risks of deficiencies or excesses that could negatively affect the health of consumers.

Iodine Supplementation Improved Antioxidant Status, Hormonal Status, Sexual Behavior, and Semen Production Performance of Bos indicus Bulls Under Tropical Climatic Condition

Iodine is anessential micronutrient that plays a crucial role in male reproduction (sexual behavior and semen production performance) by modulating thyroid function and the antioxidant status of the animal. Nonetheless, in Bos indicus bulls, a thorough evaluation of the effects of dietary iodine supplementation on antioxidant status, seminal quality parameters, and its interaction with other minerals is not documented. Twelve Bos indicus (Sahiwal) bulls were distributed into three groups (n = 4 in each group) viz. T₁ (control), T₂, and T₃ and fed diets containing 0.250, 0.375, and 0.500 ppm iodine/ kg dry matter intake, corresponding to 0%, 50%, and 100% higher than ICAR (2013) recommendations, respectively. The experimental feeding was carried out for 60 days and the effects on nutrient utilization, hormonal and antioxidant status, and sperm function tests were investigated. Results revealed that body weight, dry matter intake, and nutrient digestibility remained unaffected by dietary supplementation of iodine. Testosterone and thyroxine hormone concentrations were improved (p<0.05) in T₂ and T₃ groups. Blood and seminal iodine content were also higher (p<0.05) in both the supplemented groups (T₂ and T₃). Sperm functions viz. viability, physical membrane integrity, acrosomal integrity, motility, and mitochondrial membrane potential were improved (p<0.05) due to iodine supplementation. Furthermore, lipid peroxidation and membrane scrambling in spermatozoa were reduced (p<0.05) in T₂ and T₃ groups. Blood antioxidant status (total antioxidant activity and GPx levels) was improved (p<0.05) in T₂ and T₃. Sexual behavior was also improved (p<0.05) in iodine-supplemented groups. Hence, it can be concluded that iodine supplementation at the dose rate of 0.500 ppm in the Bos indicus bull diet is beneficial in improving hormonal status, antioxidant status, and semen quality.

Effects of Selenium Supplementation on Rumen Microbiota, Rumen Fermentation, and Apparent Nutrient Digestibility of Ruminant Animals: A Review

Enzymes excreted by rumen microbiome facilitate the conversion of ingested plant materials into major nutrients (e.g., volatile fatty acids (VFA) and microbial proteins) required for animal growth. Diet, animal age, and health affect the structure of the rumen microbial community. Pathogenic organisms in the rumen negatively affect fermentation processes in favor of energy loss and animal deprivation of nutrients in ingested feed. Drawing from the ban on antibiotic use during the last decade, the livestock industry has been focused on increasing rumen microbial nutrient supply to ruminants through the use of natural supplements that are capable of promoting the activity of beneficial rumen microflora. Selenium (Se) is a trace mineral commonly used as a supplement to regulate animal metabolism. However, a clear understanding of its effects on rumen microbial composition and rumen fermentation is not available. This review summarized the available literature for the effects of Se on specific rumen microorganisms along with consequences for rumen fermentation and digestibility. Some positive effects on total VFA, the molar proportion of propionate, acetate to propionate ratio, ruminal NH3-N, pH, enzymatic activity, ruminal microbiome composition, and digestibility were recorded. Because Se nanoparticles (SeNPs) were more effective than other forms of Se, more studies are needed to compare the effectiveness of synthetic SeNPs and lactic acid bacteria enriched with sodium selenite as a biological source of SeNPs and probiotics. Future studies also need to evaluate the effect of dietary Se on methane emissions.

China's livestock transition: Driving forces, impacts, and consequences

China's livestock industry has experienced a vast transition during the last three decades, with profound effects on domestic and global food provision, resource use, nitrogen and phosphorus losses, and greenhouse gas (GHG) emissions. We provide a comprehensive analysis of the driving forces around this transition and its national and global consequences. The number of livestock units (LUs) tripled in China in less than 30 years, mainly through the growth of landless industrial livestock production systems and the increase in monogastric livestock (from 62 to 74% of total LUs). Changes were fueled through increases in demand as well as, supply of new breeds, new technology, and government support. Production of animal source protein increased 4.9 times, nitrogen use efficiency at herd level tripled, and average feed use and GHG emissions per gram protein produced decreased by a factor of 2 between 1980 and 2010. In the same period, animal feed imports have increased 49 times, total ammonia and GHG emissions to the atmosphere doubled, and nitrogen losses to watercourses tripled. As a consequence, China's livestock transition has significant global impact. Forecasts for 2050, using the Shared Socio-economic Pathways scenarios, indicate major further changes in livestock production and impacts. On the basis of these possible trajectories, we suggest an alternative transition, which should be implemented by government, processing industries, consumers, and retailers. This new transition is targeted to increase production efficiency and environmental performance at system level, with coupling of crop-livestock production, whole chain manure management, and spatial planning as major components.

Effects of dietary supplementation of selenium and iodine on growth performance, carcass characteristics and histology of thyroid gland in goats

This study assessed the effects of dietary selenium (Se), iodine (I) and a combination of both on growth performance, thyroid gland activity, carcass characteristics and the concentration of iodine and selenium in Longissimus lumborum (LL) muscle in goats. Twenty-four bucks were randomly assigned to four dietary treatments: control (CON), basal diet without supplementation, basal diet + 0.6 mg Se/kg dry matter (DM) (SS), 0.6 mg I/kg DM (IP), or combination of 0.6 mg/kg DM Se and 0.6 mg/kg DM I (SSIP) and fed for 100 days. Animals fed diet SSIP exhibited higher (P < 0.05) body weight and better feed conversion ratio (FCR) than those fed other diets. Dressing percentage of goats fed the supplemented diets was higher (P < 0.05) than that of the control. Carcasses from the IP group had higher (P < 0.05) total fat proportion than the SSIP group. The levels of both elements were significantly elevated (P < 0.05) in LL muscle in supplemented goats. Thyroid follicular epithelial cells of IP and SSIP animals were significantly higher than those of CON and SS groups. The study demonstrated that the combined Se and I dietary supplementation improves growth performance, carcass dressing percentage and increases the retention of Se and I in goat meat.

Blood haematology, serum thyroid hormones and glutathione peroxidase status in kacang goats fed inorganic iodine and selenium supplemented diets

The effects of dietary supplementation of selenium (Se), iodine (I), and a combination of both on the blood haematology, serum free thyroxine (FT4) and free triiodothyronine (FT3) hormones and glutathione peroxidase enzyme (GSH-Px) activity were examined on twenty four (7 to 8 months old, 22±1.17 kg live weight) Kacang crossbred male goats. Animals were randomly assigned to four dietary treatments (6 animals in each group). Throughout 100 d of feeding trial, the animals of control group (CON) received a basal diet, while the other three groups were offered basal diet supplemented with 0.6 mg/kg diet DM Se (SS), or 0.6 mg/kg diet DM I (PI), or a combination of both Se and I, each at 0.6 mg/kg diet DM (SSPI). The haematological attributes which are haemoglobin (Hb), red blood cell (RBC), packed cell volume (PCV), mean cell volume (MCV), white blood cells (WBC), band neutrophils (B Neut), segmented neutrophils (S Neut), lymphocytes (Lymph), monocytes (Mono), eosinophils (Eosin) and basophils (Baso) were similar among the four treatment groups, while serum levels of Se and I increased significantly (p<0.05) in the supplemented groups. The combined dietary supplementation of Se and I (SSPI) significantly increased serum FT3 in the supplemented animals. Serum GSH-Px activity increased significantly in the animals of SS and SSPI groups. It is concluded that the dietary supplementation of inorganic Se and I at a level of 0.6 mg/kg DM increased serum Se and I concentration, FT3 hormone and GSH-Px activity of Kacang crossbred male goats.

Protective roles of selenium on nitric oxide-mediated apoptosis of immune organs induced by cadmium in chickens

Little is known about the influence of subchronic cadmium exposure on apoptosis in the immune organs of birds and the protective effects on apoptosis by selenium against cadmium. The aim of this study was to investigate the effect of subchronic cadmium exposure on nitric oxide and apoptosis in the immune organs of chicken and the protective roles of selenium against cadmium-induced apoptosis. Two hundred ten 30-day-old chickens were randomly assigned to three groups and were fed a basal diet, cadmium+selenium (as 150 mg of CdCl2 per kg of diet+10 mg of Na2SeO3 per kg of diet ) or cadmium (as 150 mg of CdCl2 per kg of diet) in basic diets for 15, 30, 45, and 60 days. Then, the production of nitric oxide, messenger RNA (mRNA level), and the activity of inducible nitric oxide synthase, ultrastructural changes, TUNEL assay, and flow cytometric analysis of apoptosis and Bcl-2 and p53 mRNA levels in the immune organs were examined. The results showed that cadmium exposure caused ultrastructural damage and increased production of nitric oxide, mRNA level, and activity of inducible nitric oxide synthase, the degree, and the number of apoptotic cells in a time-dependent manner. Cadmium exposure decreased Bcl-2 mRNA level and increased p53 mRNA level in a time-dependent manner. Selenium supplementation during dietary cadmium reduced the production of nitric oxide, the mRNA level, and activity of inducible nitric oxide synthase, ultrastructural damage, and apoptosis in the immune organs of chicken. It indicated that cadmium induced nitric oxide-mediated apoptosis of immune organs, and selenium played protective effects against cadmium-induced apoptosis in the immune organs of chickens.

Dietary iodine and selenium affected the mRNA expression levels of skin monodeiodinase (II, III) in Liaoning Cashmere goats

Livestock are frequently provided nutrient-depleted diets, which can negatively impact animal health and productivity. In our previous trial, we found that iodine (I) supplementation (not selenium (Se)) could increase cashmere production. In order to explore the role of I and Se in cashmere growth, we investigated the effects of dietary I and Se supplementation in Liaoning cashmere goats. Serum thyroid hormone status and the mRNA expression levels of skin monodeiodinase (MDII, MDIII) were measured during the cashmere fiber growth period. Forty-eight 2.5-year-old Liaoning cashmere goats (38.6 ± 2.65 kg BW) were divided into six equal groups, and their diets were supplemented with I (0, 2, or 4 mg/kg DM) and Se (0 or 1 mg/kg DM) in a 2 × 3 factorial treatment design. The six treatment groups were: I(0)Se(0), I(2)Se(0), I(4)Se(0), I(0)Se(1), I(2)Se(1), and I(4)Se(1). Concentrations of I and Se in the basal diet (group I(0)Se(0)) were 0.67 and 0.09 mg/kg DM, respectively. The trial started in September of 2009 and lasted 70 days. For every measured parameter, supplemental Se had no significant effect on thyroid hormones, but improved the mRNA expression levels of skin MDIII (P < 0.01). However, supplemental I increased levels of thyroid hormones (thyroxine and triiodothyronine) and improved the mRNA expression levels of skin MDII (P < 0.05). These results show that the addition of I to cashmere goat feedstock may be an effective means of increasing cashmere production through thyroid hormones regulating the mRNA expression of skin MDII.

Selenium, selenoprotein genes and Crohn's disease in a case-control population from Auckland, New Zealand

New Zealand has one of the highest incidence rates of Crohn’s Disease (CD), whilst the serum selenium status of New Zealanders is amongst the lowest in the world. A prospective case-control study in Auckland, New Zealand considered serum selenium as a potential CD risk factor. Serum selenium levels were significantly lower in CD patients compared to controls (101.8 ± 1.02 vs. 111.1 ± 1.01 ng/mL) (p = 5.91 × 10⁻⁸). Recent detailed studies in the United Kingdom have suggested an optimal serum level around 122 ng/mL, making the average CD patient in New Zealand selenium deficient. Of the 29 single nucleotide polymorphisms (SNPs) tested, 13 were found to significantly interact with serum selenium on CD. After adjustment for multiple testing, a significant interaction with serum selenium on CD was found for three SNPs, namely rs17529609 and rs7901303 in the gene SEPHS1, and rs1553153 in the gene SEPSECS. These three SNPs have not been reported elsewhere as being significantly associated with selenium or CD. It is unclear as to whether lower selenium levels are a cause or an effect of the disease.

Effect of selenium, zinc, and copper supplementation on blood metabolic profile in male buffalo (Bubalus bubalis) calves

Twenty male buffalo calves (15 months, 200.2 ± 9.75) were divided into four groups of five animals in each and fed diets without (T1) or supplemented with 0.3 ppm selenium (Se) + 40 ppm zinc (Zn) (T2), 0.3 ppm Se + 40 ppm Zn + 10 ppm copper (Cu) (T3), and 40 ppm Zn + 10 ppm Cu (T4) for 120 days, during which blood samples were collected on days 0, 40, 80, and 120. Concentrations of glucose, total protein, albumin, globulin, urea, uric acid, and creatinine were similar in all the four groups. The level of different serum enzymes viz. lactate dehydrogenase, alkaline phosphatase, glutamate pyruvate transaminase, and glutamate oxaloacetate transaminase, and hormones viz. T(3), T(4), testosterone and insulin were similar (P > 0.05) among the four groups but the ratio of T(4)/T(3) was reduced (P < 0.05) in the groups (T2 and T3) where selenium was supplemented at 120th day of supplementation. It was deduced that supplementation of 0.3 ppm Se and/or 10.0 ppm of Cu with 40 ppm Zn had no effect on blood metabolic profile in buffalo calves, except the ratio of T(4) and T(3) hormone which indicates that selenium plays an important role in converting T(4) hormone to T(3) which is more active form of thyroid hormone.

Thyroid hormones in milk and blood of lactating donkeys as affected by stage of lactation and dietary supplementation with trace elements

The traditional utilization of donkeys (Equus asinus) as dairy animals has recently attracted substantial scientific interest with regard to human nutrition. Donkey milk is well tolerated by infants with cows’ milk allergy, useful in the treatment of human immune-related diseases, in the prevention of atherosclerosis, and in-vitro studies showed an anti-proliferative effect. Active 3-3′-5-triiodothyronine (T3) in colostrum and milk could play different physiological roles, systemic and paracrine, for both the mother and the suckling offspring. The aim was to evaluate whether thyroid hormones (TH) concentrations in milk and blood of lactating donkeys change with the advancing lactation and whether they can be affected by dietary supplementation with several trace elements, some of them directly involved with TH synthesis (I), metabolism (Se) and action (Zn). Sixteen lactating jennies were divided into two groups (CTL and TE). Mixed feed for TE was added with Zn, Fe, Cu, Mn, I, Se and Co. Every 2 weeks milk and blood samples were collected at 11·00. Total concentrations of T3 in milk (T3M) and T3 and T4 in plasma (T3P and T4P) were assayed using ELISA kits, validated for the donkey species. T3M was not correlated with TH concentrations in blood, did not change with the stage of lactation, and was significantly higher in TE (4·09±0·07 ng/ml, mean±se) than in CTL group (3·89±0·08 ng/ml). T4P (81·8±5·2 ng/ml) and T3P (15·2±1 ng/ml) significantly changed with time, but were not significantly affected by dietary treatment. T3P/T4P ratio was significantly lower in TE group. This study indicates that in donkey milk the concentration of T3, a human-like bioactive compound, can be affected by trace elements intake.