Safety and efficacy of Zinc-l-Selenomethionine as feed additive for all animal species

Consumer safety of feed additives containing selenium

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety for the consumer of products from animals fed diets with feed additives containing selenium as an active substance. Based on the limited data set available and the several uncertainties, the FEEDAP Panel concluded that the use of organic selenium at the currently maximum authorised use level of 0.2 mg supplemented selenium from organic sources/kg complete feed (within a maximum of 0.5 mg total selenium/kg complete feed) leads to an exceedance of the UL for all the population categories (except elderly and very elderly), suggesting a concern for consumer safety. It was not possible to conclude on the safety of the currently maximum use level of 0.5 mg total selenium/kg complete feed for all consumer categories. Additional data from studies specifically designed to measure deposition of selenium in tissues and products from animal origin resulting from the use of the different sources of selenium would be required to perform a proper risk assessment.

Modification of the terms of authorisation of zinc-l-selenomethionine as a feed additive for all animal species (Zinpro Animal Nutrition (Europe), Inc.)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a new preparation of zinc-l-selenomethionine, with selenium content of 4%, as a nutritional feed additive for all animal species. Zinc-l-selenomethionine is already authorised for use in all animal species (3b818). Current authorisation defines the additive as 'Solid preparation of zinc-l-selenomethionine with a selenium content of 1-2 g/kg'. The applicant developed a new preparation of zinc-l-selenomethionine containing a minimum of 40 g Se/kg and seeks to modify the current authorisation. The FEEDAP Panel concluded that the newly proposed preparation is considered safe for all animal species. The FEEDAP Panel recommends adding, to the currently existing authorisation, a new preparation (40-46 g Se/kg) and not the range proposed by the applicant (1-46 g Se/kg), since no characterisation data on the intermediate preparation range (from 2 to 40 g Se/kg) have been provided. The use of the new preparation (minimum 40 g Se/kg) of zinc-l-selenomethionine in animal nutrition is of no concern for consumer safety. The newly proposed preparation presents a risk by inhalation; it is not irritant to eyes or skin. No conclusion can be reached regarding dermal sensitisation. The previous conclusion by the Panel on the safety for the environment remains unchanged. The Panel concluded that the modification request has no impact on efficacy.

Effects of feeding diets with zinc-l-selenomethionine on growth performance of broilers subjected to cyclic heat stress

Limited information exists on the use of zinc-l-selenomethionine (Zn-L-SeMet) in broiler diets and its effects on the growth performance, body temperature, mortality rates, blood profile, and gene expression, especially when animals are reared under cyclic heat stress conditions. This study aimed to investigate the impact of Zn-L-SeMet in broiler diets from 1 to 42 days of age reared under cyclic heat stress and its effects on growth performance, cloacal temperatures, mortality rate, blood parameters, and insulin-like growth factor 1 (IGF-1) and growth hormone receptor (GHR) gene expression in the breast muscle. A total of 1000 male Cobb 500® broiler chicks were randomly assigned to five treatments: 0, 0.15, 0.23, 0.47, and 1.30 mg/kg of Zn-L-SeMet. Each treatment consisted of 10 replicates with 20 birds each. No statistically significant differences in growth performance were observed from 1 to 21 days of age (P > 0.05). However, from 1 to 42 days, feed intake (FI) and feed conversion ratio (FCR) decreased linearly (P < 0.05). Cloacal temperatures showed no significant effects (P > 0.05), while overall mortality rate exhibited a quadratic response (P < 0.05), with the optimal inclusion level predicted to reduce broiler mortality at 0.71 mg/kg. Triglyceride (TRG) levels increased with 0.97 mg/kg (P < 0.05), and gama-glutamil transferase (GGT) levels decreased with the inclusion of 1.19 mg/kg (P < 0.05). No significant effects on IGF-1 and GHR gene expression were found (P > 0.05). In conclusion, the inclusion of 1.30 mg/kg of Zn-L-SeMet in diets of heat-stressed broilers improved growth performance from 1 to 42 days of age. An inclusion of 0.71 mg/kg reduced mortality rate, while 0.97 mg and 1.19 mg increased and reduced TRG and GGT levels, respectively.

Epigenetic effects of selenium and vitamin E supplementation in broiler breeder diets on the performance of their progeny

Nutritional supplements have been commonly used in the poultry industry last few years. The study aimed to investigate the epigenetic effects of adding vitamin E and organic selenium to the diet of broiler breeders Ross-308 on their progeny meat production performance. The treatments included the control group fed with a standard diet without supplementation (T1), T2 using a standard diet supplemented with 500 mg of vitamin E / kg, T3 using a standard diet supplemented with 0.5 mg of organic selenium (Availa powder) /kg, and T4 using a standard diet supplemented with a mixture of vitamin E and organic selenium in proportions 500 and 0.5 mg/kg respectively. The eggs were collected from each treatment to obtain the progeny reared for 35 periods, and measurements were recorded for meat production and carcass traits. The results showed that the treatments had significant epigenetic effects on body weight at hatching. Hence, T2 had a significantly heavier body weight than T1, while no significant differences were observed between T3 and T4. The result of T2 recorded extremely high feed intake compared with T3. On the other hand, T3 and T4 recorded a hefty weight of breast parts compared with T1 and T2. In conclusion, organic selenium supplementation led to a significant increase in breast weight and a decrease in thigh part weight compared to the control group. In contrast, vitamin E supplementation led to an increase in chick weight at hatch, a reduction of total mortality and an improvement in feed conversion ratio compared to the control group. This refers to the epigenetic effects of organic selenium and vitamin E on progeny traits when added to the breeder diet. Keywords: Epigenetics, broiler, selenium supplementation, meat production

Effect of Antioxidant Supplementation on Milk Yield and Quality in Italian Mediterranean Lactating Buffaloes

Buffaloes are raised mainly to obtain milk that is nutritionally very rich. The technological characteristics of buffalo milk are optimal for processing into cheese, and it is mainly used to produce mozzarella cheese. Under stressful conditions, buffaloes, like other animals, produce milk qualitatively poorly. The stressors that can affect the quality of production are, in addition to other factors, deficiencies in nutrients such as vitamins, antioxidants, and minerals. In this study, we evaluated the effect of antioxidant supplementation on the quality of buffalo milk. Sixty-six buffaloes were enrolled and subdivided into two balanced groups of 33 each. The ZnSe group received 0.2 kg/head/day of Bufalo Plus® containing antioxidants and barley meal, CaCO3 and MgCO3 mix; the control group was supplemented with 0.2 kg/head/day of barley meal, CaCO3 and MgCO3 mix. The two groups were fed ad libitum with a total mixed ration (TMR). The amount of diet distributed was recorded daily, and the residue in the trough manger was recorded three times per week. TMR samples were taken every two weeks for each group. Daily milk yield was recorded twice a week. Milk samples were collected every four weeks and analysed for chemical and technological properties. Furthermore, milk total antioxidant capacity was determined. The results obtained showed that the antioxidant supplement had no effect on feed intake, feeding behaviour, and feed efficiency. The treatment positively influenced milk production while it did not affect the chemical characteristics of the milk. In addition, the supplement of antioxidants improved the milk clotting properties (MCP). The supplement did not affect the antioxidant activity of the milk.