Variation in the link between oxygen consumption and ATP production,and its relevance for animal performance

It is often assumed that an animal''s metabolic rate can be estimated through measuring the whole-organism oxygen consumption rate. However, oxygen consumption alone is unlikely to be a sufficient marker of energy metabolism in many situations. This is due to the inherent variability in the link between oxidation and phosphorylation; that is, the amount of adenosine triphosphate (ATP) generated per molecule of oxygen consumed by mitochondria (P/O ratio). In this article, we describe how the P/O ratio can vary within and among individuals, and in response to a number of environmental parameters, including diet and temperature. As the P/O ratio affects the efficiency of cellular energy production, its variability may have significant consequences for animal performance, such as growth rate and reproductive output. We explore the adaptive significance of such variability and hypothesize that while a reduction in the P/O ratio is energetically costly, it may be associated with advantages in terms of somatic maintenance through reduced production of reactive oxygen species. Finally, we discuss how considering variation in mitochondrial efficiency, together with whole-organism oxygen consumption, can permit a better understanding of the relationship between energy metabolism and life history for studies in evolutionary ecology.     

Correlation between the consumption of amino acids and the production of the antibiotic gallidermin by Staphylococcus gallinarum

The correlation between the consumption of amino acids and the production of the polypeptide antibiotic gallidermin by Staphylococcus gallinarum Tü 3928 was investigated by on-line determination of amino acids and pulse experiments. A prolonged production phase together with an increase in gallidermin formation of about 25% was obtained during pulse and fed-batch experiments with the amino acids glutamic acid, glycine, serine and threonine.     

Gender as a factor in an environmental assessment of the consumption of animal and plant-based foods in Germany

Purpose

Due to their production intensity, different foods of animal or plant origin play a crucial role in the assessment of the environmental impacts of human nutrition and diets. Based on a representative nutrition survey in Germany from the year 2006, a life cycle assessment (LCA) was conducted to quantify nutrition-related emissions of animal and plant-based foods (excluding beverages), with a special focus on the socio-demographic factor gender.

Materials and methods

For the study, representative data sets concerning German food production and consumption were used. These were complemented by the Danish LCA Food database and other LCA data to analyse the impact of food imports. As regards environmental impact assessment, global warming potential (GWP) was assessed, which included emissions from direct land use change and land use (dLUC, LU), along with three inventory indicators (ammonia emissions, land use, blue water use). The following food groups were analysed from cradle-to-store and their impacts were evaluated and compared with each other: animal-based foods (meat products, milk products, egg products and fish products), plant-based foods (grain products, vegetables, fruits, potato products, margarine/oils, sugar/sweets). The reference year in the study is the year 2006.

Results and discussion

For all indicators, the results show strong variation between the genders. Even if the physiologically different consumption patterns among men and women are adjusted on a weight basis, men show a higher impact in terms of GWP (CO₂ eq. +25%), ammonia emissions (+30%) and land use (+24%). In contrast, women demonstrate a higher water demand (+11%). These differences are primarily caused by a higher share of meat and meat products in the usual diet of men (+28%) as well as of fruit and vegetables in the diet of women (+40%). If men were to shift qualitatively to the usual diet of women, then 14.8 Mt CO₂ eq. and 60.1 kt ammonia emissions could be saved annually. Within the system boundaries of our study, this would translate into a reduction of 12% of CO₂ eq. and 14% of ammonia emissions. With regard to land use, this equals an area of 15,613?km²?year^?1 (?11%), whereas the total blue water demand would be increased by 94?Mm³?year^?1 (+7%). Limitations within this study are caused by the system boundaries cradle-to-store and are also due to the restricted set of environmental indicators which were analysed. Nonetheless, our results for GWP and land use are in keeping with previous studies. The results concerning ammonia and blue water use are limited when compared with other study results.

Conclusions

The study shows that within one society distinct diet profiles with markedly different environmental impacts are already established. Taking cultural and physiological considerations among the genders into account, these differences could be seen as offering potential opportunities to strengthen sustainable diet profiles. Further research should also consider health impact assessments to ensure that alterations in diet profiles due to environmental constraints do not lead to disadvantageous public health effects. Particular attention should be paid here to potentially undernourished subgroups (such as the elderly, sick people, pregnant women).     

An exploration on greenhouse gas and ammonia production by insect species suitable for animal or human consumption

Background

Greenhouse gas (GHG) production, as a cause of climate change, is considered as one of the biggest problems society is currently facing. The livestock sector is one of the large contributors of anthropogenic GHG emissions. Also, large amounts of ammonia (NH₃), leading to soil nitrification and acidification, are produced by livestock. Therefore other sources of animal protein, like edible insects, are currently being considered.

Methodology/Principal Findings

An experiment was conducted to quantify production of carbon dioxide (CO₂) and average daily gain (ADG) as a measure of feed conversion efficiency, and to quantify the production of the greenhouse gases methane (CH₄) and nitrous oxide (N₂O) as well as NH₃ by five insect species of which the first three are considered edible: Tenebrio molitor, Acheta domesticus, Locusta migratoria, Pachnoda marginata, and Blaptica dubia. Large differences were found among the species regarding their production of CO₂ and GHGs. The insects in this study had a higher relative growth rate and emitted comparable or lower amounts of GHG than described in literature for pigs and much lower amounts of GHG than cattle. The same was true for CO₂ production per kg of metabolic weight and per kg of mass gain. Furthermore, also the production of NH₃ by insects was lower than for conventional livestock.

Conclusions/Significance

This study therefore indicates that insects could serve as a more environmentally friendly alternative for the production of animal protein with respect to GHG and NH₃ emissions. The results of this study can be used as basic information to compare the production of insects with conventional livestock by means of a life cycle analysis.     

Binational evaluation of type traits from Germany and France with a single-trait MACE animal model

Binational genetic evaluation between Germany and France were performed for each type trait using a single-trait MACE (multiple across-country evaluation) model. Daughter yield deviations (DYD) of bulls having 30 equivalent daughter contributions or more were the data for parameter estimation. Full pedigree information of bulls was used via sire and dam relationships. In general, across-country genetic correlation estimates were in agreement with what is observed by Interbull. The estimated correlations were over 0.93 for stature, rump angle, udder depth, front teat placement, teat length and rear teat placement. These traits have been classified in both countries for a long period of time. However, some other type traits were included later in the French type classification system (most of them since 2000): chest width, body depth, angularity, rump width, rear leg rear view, fore udder and rear udder height. The estimated correlations for these traits were relatively low. In order to check changes in genetic correlations over time, data from bulls born until the end of 1995 were discarded. Higher genetic correlation estimates between both countries were obtained by using more recent data especially for traits having lower genetic correlation, e.g. body depth correlation increased from 0.55 to 0.83. Once genetic correlations were estimated, binational genetic evaluation between Germany and France were performed for each type trait using DYD of bulls. The rankings of bulls obtained from this evaluation had some differences with Interbull rankings but a similar proportion of bulls from each country was found. Finally, more computationally demanding binational evaluations were performed using yield deviations of cows for binational cow comparison. The rankings obtained were influenced by the number of daughters per bull and heritabilities used in each country.     

Co-regulation of motility, exoenzyme and antibiotic production by the EnvZ-OmpR-FlhDC-FliA pathway in Xenorhabdus nematophila

Xenorhabdus nematophila is an emerging model for both mutualism and pathogenicity in different invertebrate hosts. Here we conduct a mutant study of the EnvZ-OmpR two-component system and the flagella sigma factor, FliA (sigma28). Both ompR and envZ strains displayed precocious swarming behaviour, elevated flhD and fliA mRNA levels and early production of lipase, protease, haemolysin and antibiotic activity. Inactivation of fliA eliminated exoenzyme production which was restored by complementation with the fliAZ operon. Inactivation of flhA, a gene encoding a component of the flagella export apparatus, eliminated lipase but not protease or haemolysin production indicating these enzymes are secreted by different export pathways. FliA-regulated lipase (xlpA) and protease (xrtA) genes were identified. Their expression and level of production were elevated in the ompR and envZ strains and markedly reduced in the fliA strain while both were expressed normally in the flhA strain. We also found that expression of nrps1 which encodes a non-ribosomal peptide synthetase was elevated in the ompR and envZ strains. The fliA strain was pathogenic towards the insect host indicating that motility and FliA-regulated exoenzyme production were not essential for virulence. These findings support a model in which the EnvZ-OmpR-FlhDC-FliA regulatory network co-ordinately controls flagella synthesis, and exoenzyme and antibiotic production in X. nematophila.     

Embryo technologies and animal health - consequences for the animal following ovum pick-up, in vitro embryo production and somatic cell nuclear transfer

Mammalian reproductive technologies that aim either to complement or to transcend conventional livestock breeding options have contributed to some of the most remarkable achievements in the field of reproductive biology in recent decades. In so doing they have extended our horizons in two distinct dimensions, the first concerning what it is technically possible to achieve and the second relating to the time-frame within which an individual's life-long developmental capability is initially established and ultimately realized or undermined. Our impressions of the benefits and values, or otherwise, of technologies such as in vitro embryo production and nuclear transfer are rightly influenced by the extent to which they impinge on the health of animals either subjected to or derived from them. Here, we consider some of the health implications of oocyte/embryo-centric technologies applied to farm livestock.     

Effects of nutrients on the production of AK-111-81 macrolide antibiotic by Streptomyces hygroscopicus

The influence of different carbon and nitrogen sources on the production of AK-111-81 nonpolyenic macrolide antibiotic by Streptomyces hygroscopicus 111-81 was studied. Substitution of glucose with lactose or glycerol significantly affected maximal antibiotic AK-111-81 productivity as the growth rate was close to that of the basal fermentation medium. Addition of ammonium succinate to the fermentation medium markedly increased the antibiotic productivity as the growth rate was low. Divalent ions as Mn2+, Cu2+, Fe2+ stimulated AK-111-81 antibiotic biosynthesis. These results allow us to develop a new fermentation medium showing 6-fold increase of AK-111-81 antibiotic formation compared with the basal fermentation medium.     

Geophagy in chacma baboons: patterns of soil consumption by age class, sex, and reproductive state

Despite baboons' widespread distribution across Africa, geophagy among all subspecies has been poorly documented. We used video camera traps and soil analyses to investigate geophagy in chacma baboons (Papio cynocephalus ursinus) inhabiting the Western Cape of South Africa. During an 18‐month study, from August 2009 to January 2011, we continually monitored the largest and most frequently visited geophagy sites with camera traps for 545 days and captured soil consumption at one or more sites on 266 of those days (49%). In 3,500 baboon visits to geophagy sites, video camera traps captured 58.6 hr of geophagy. From these data, we evaluated site preference based on time spent consuming soil among these four geophagy sites. One hundred and seventy days of soil consumption data from the most frequently visited geophagy site allowed us to look for demographic trends in geophagy. Selected consumed soils from geophagy sites were analyzed for mineral, physical, and chemical properties. The baboons spent more time consuming white alkaline soils with high percentages of clay and fine silt, which contained higher concentrations of sodium than non‐white acidic soils that contained higher concentrations of iron. Our data indicate that pregnant chacma baboons spent more time consuming soil at monitored geophagy sites than baboons of any other age class, sex, or reproductive state. Based on analytical results, the soils consumed would be effective at alleviating gastrointestinal distress and possibly supplementing minerals for all age/sex classes, but potentially for different age/sex requirements. Am. J. Primatol. 74:48–57, 2012. © 2011 Wiley‐Liss, Inc.