Supplemental feeding on rangelands:new dynamics of the livestock in the El Ouara rangelands in southern Tunisia

Fodder production in arid rangelands has been traditionally considered as the main source of nutrition for livestock.However,the production of these fodder may be influenced by some socio-economic and climatic factors.This study aims to identify the various rangeland use forms and determine the types of livestock feeding system in the El Ouara rangelands of Ben guarden District in southern Tunisia by analysing the importance of supplemental feeding and main determinants of this practice.Data were collected by a survey that targeted a sample of 50 breeders in the El Ouara rangelands.Descriptive statistics and binary logistic regression were used to analyse the data.The results showed that there are two types of association practiced by breeders:“Cherka”association practiced by 10.00% of breeders and cash payment association practiced by 53.00% of breeders.Then,transhumance,sedentary,and semi-urban forms are the main ways in which breeders use the rangelands.There are four livestock feeding systems in the El Ouara rangelands being used to feed livestock:natural rangeland,rangeland-based,mixed,and concentrate-based feeding systems.Supplemental feeding has become fundamental for the livestock feeding system in the El Ouara rangelands.The breeders with the largest camel size still use the natural rangeland feeding system,while the breeders who have the largest herd size practice the mixed feeding system.The logistic regression results reveal that breeder age,cereal area,herd size,migrant remittance,second activity,and agricultural development group membership can significantly impact the supplemental feeding.In summary,this study can help policy-makers plan innovative practices based on climatic change,ensure the sustainability of livestock feeding system,and make effective decisions for local development.

Feeding Supplemental lodine to Adult Mink;Effect on Thyroid Hormones in Adult and offspring

We fed adult mink diets containing supplemental iodine, from 0 to 320 ppm, for one or seven months prior to breeding. Blood samples collected from the adults and their offspring (kits) at 4 wk post-partum were assayed for total thyroxine (T4), triiodothyronine (T3), reverse T3 (rT3), and T4-binding indices. As expected T4 concentrations of the adult and kit mink varied inversely with the level of supplemental iodine. In addition, T3 and rT3 concentrations decreased gradually in kits from the long-term experiment in response to the increased dietary iodine of the dams. T3 concentrations of kits from dams fed iodine short-term decreased markedly while rTy concentrations were elevated greatly in response to increased dietary iodine of the dam. These decreases in hormone levels are due to serum iodine blocking the thyroid uptake of iodine and subsequent decrease of hormone synthesis. Excess iodine may also block the effect of thyroid stimulating hormone. The T4-binding indices of the adults, in general, were depressed, while the T4-binding indices of the kits were more variable. These effects are probably due to fluctuations in thyroglobulin.

The Effects of Nutrition Lick Brick and Salt Brick as Supplement Feed on the Production Performance of Tan Sheep

In the paper, the effects of nutrition lick brick and salt brick as supple-ment feed on the performance of Tan sheep were studied. 36 fattening Tan sheep with the average weight of about 23 kg were chosen, they were randomly divided into 3 groups according to the weight, and each group had 12 sheep. Control group was fed with normal daily ration, experimental group 1 was fed with normal daily ration＋nutrition lick brick, experimental group 2 was fed with normal daily ration＋salt brick, the experimental period was 60 d. The results showed that 1） compared with CK, daily gain of group 1 improved 17.09%（P〈0.01）, feed conversion ratio reduced 11.69%（P〈0.05）, and average gross profit per sheep improved 51.65 yuan; daily gain of group 2 improved 7.03%（P〈0.05）, feed conversion ratio reduced 4.06%（P〉0.05）, and average gross profit per sheep improved 19.78 yuan; 2） compared with group 2, daily gain of group 1 improved 9.40%（P〈0.05）, feed conversion ratio re-duced 7.96%（P〈0.05）, and average gross profit per sheep improved 31.87 yuan;these indicated that nutrition lick brick and salt brick as supplement feed for Tan sheep both can improve the production performance of Tan sheep, and the supple-mentary feeding effect of nutrition lick brick was better.

Role of copper chelating agents: between old applications and new perspectives in neuroscience

The role of copper element has been an increasingly relevant topic in recent years in the fields of human and animal health, for both the study of new drugs and innovative food and feed supplements. This metal plays an important role in the central nervous system, where it is associated with glutamatergic signaling, and it is widely involved in inflammatory processes. Thus, diseases involving copper(Ⅱ) dyshomeostasis often have neurological symptoms, as exemplified by Alzheimer's and other diseases(such as Parkinson's and Wilson's diseases). Moreover, imbalanced copper ion concentrations have also been associated with diabetes and certain types of cancer, including glioma. In this paper, we propose a comprehensive overview of recent results that show the importance of these metal ions in several pathologies, mainly Alzheimer's disease, through the lens of the development and use of copper chelators as research compounds and potential therapeutics if included in multi-target hybrid drugs. Seeing how copper homeostasis is important for the well-being of animals as well as humans, we shortly describe the state of the art regarding the effects of copper and its chelators in agriculture, livestock rearing, and aquaculture, as ingredients for the formulation of feed supplements as well as to prevent the effects of pollution on animal productions.

Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms

Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers’ yeast from large breweries has been used as a protein supplement in cattle;however the possible advantages of spent yeast from smaller craft breweries, containing much higher levels of bioactive hop acids, have not been evaluated. Hops secondary metabolites from the hops (Humulus lupulus L.) used to make beer are concentrated in the yeast during brewing, and have antimicrobial activity against Gram-positive bacteria. Uncultivated suspensions of bovine rumen microorganisms produced less methane during fructose fermentation when exposed to inactivated, and freeze-dried spent craft brewers’ yeast than a bakers’ yeast control. The experiment was repeated with caprine rumen microorganisms and ground grass hay as the substrate. Likewise, in the presence of craft brewers’ yeast less methane was produced (2.7% vs. 6.9% CH4). Both experiments also revealed a decrease in acetic acid production, but not propionic acid production, when craft brewers’ yeast was included. These results indicated that spent yeast could represent a co-product for craft breweries, and a feed supplement for ruminants that has a favorable impact on methane production.

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background：Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed.It is believed that along with biodiesel from algae,the high protein de-oiled algal residue may become an alternative feed supplement option in the future.This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species,Thalassiosira weissflogii,Selenarstrum capricornutum,Scenedesmus sp.,and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean（Glycine max） meal and alfalfa（Medicago sativa） hay.Results：With the exception of T.weissflogii,algal residue had higher concentrations of Cu,Zn,and Mn and lower concentration of Ca,Mg,and K than soybean meal and alfalfa hay.The algal residue CP（crude protein）concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues.In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve,interpreted with a dual pool logistic model,confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay,and the fermenting rate of the fractions was also low.Conclusions：Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.