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Nutrition and Digestion in Horses

Unlike cattle which have several stomachs (and there own interesting digestion system), horses have only one stomach. Like cattle their natural diet is grass. With feed provided by people, horses can run into issues they don’t experience from their natural diet. Fresh grass is fibrous and slows down digestion. If feed is used the feeding should be spread out several times during the day, due to the horses digestive system.

image of the digestive system of a horse

image via eXtention [broken link has been removed]. The next 4 paragraphs are slightly edited quotes from the link.

The small intestine is the main site of digestion and absorption of protein, energy, vitamins and minerals.

The cecum is located after the small intestine of a horse and it functions much like the rumen of a cow (as a fermentative vat housing microbes which aid digestion). These microbes break down nutrient sources that would otherwise be unavailable to the horse.

The cecum and colon house bacterial, protozoal and fungal populations which function in microbial digestion of feed material in the digestive tract. Many different products of microbial digestion are absorbed by the horse.

Among other benefits, incorporating long-stem forage into rations increases particle size of ingested matter, thus slowing rate of passage. It also increases dry matter intake, thus stimulating water intake.

Nutrients and Common Feed Sources for Horses [broken link has been removed] from the extension service (USA land grant universities)

Carbohydrates provide the majority of a horse’s energy. Non-structural carbohydrates, such as starch and glucose from grains and gums and pectins from fiber, are readily utilized as energy sources for the horse. The enzyme amylase breaks down non-structural carbohydrates into glucose and simple sugars, which are absorbed in the small intestine.

Structural carbohydrates, such as cellulose and hemicellulose in plants, can only be broken down by bacterial enzymes in the cecum and colon. The microorganisms convert these carbohydrates to volatile fatty acids (acetate, propionate, butyrate), which can provide 30 to 70 percent of the horse’s energy requirement.

Fibrous feeds are a very important part of the horse’s diet. They provide nutrients for both the horse and microbes in the hindgut as well as stimulate muscle tone and activity of the gastrointestinal tract.

Mineral supplements are usually required in the horse’s diet. Macrominerals are added to a horse’s diet to balance the ration to meet mineral requirements.

Human raised horses usually have some grazing but get some or much of there food needs from feed. Those feeds often supplement normal food for wild horses with beets, apples, carrots and other sources. In addition the horse food supplements include minerals, fiber and even pre-biotics and pro-biotics (just like our processed food does).

As a general rule, horses need 1 to 2 quarts (2 to 4 liters per kilogram) of water per pound of dry matter consumed. Of course, other factors can increase the water need, such as exercise (since it results in water loss through sweating).

Related: Great Webcast Explaining the Digestive SystemsEnergy Efficiency of DigestionTracking the Ecosystem Within Us

USA Designates Large Areas of New Mexico and Arizona as Critical Habitat for Jaguars

The U.S. Fish and Wildlife Service has designated 764,200 acres of critical habitat for the jaguar (Panthera onca) under the Endangered Species Act (ESA). This habitat is found within Pima, Santa Cruz and Cochise counties in Arizona, and Hidalgo County in New Mexico.

The final rule reflects the following changes from the July 1, 2013, critical habit at proposal: exclusion of Tohono O’odham Nation lands (78,067 acres) as a result of the Tribe’s efforts working in partnership with the Service to conserve jaguar and other listed species’ habitat on the Nation’s sovereign land. Exemption of Fort Huachuca lands (15,867 acres) due to the conservation benefits to the jaguar provided in Fort Huachuca’s approved Integrated Natural Resource Management Plan.

The revised proposal was based on an updated habitat modeling report that more accurately reflected habitat essential to jaguars in northwestern Mexico and southwestern United States.

Mexico borderlands area is very different from habitat in Central and South America, where jaguars show a high affinity for lowland wet communities. Jaguars have been documented in arid areas of northwestern Mexico and southwestern United States, including thornscrub, desertscrub, lowland desert, mesquite grassland, Madrean oak woodland and pine oak woodland communities. Critical habitat in the United States contributes to the jaguar’s persistence and recovery across the species’ entire range by providing areas to support individuals that disperse into the United States from the nearest core population in Mexico.

Critical habitat is a term defined in the ESA and identifies geographic areas containing features essential to the conservation of a threatened or endangered species and that may require special management considerations or protection. The designation of critical habitat does not affect land ownership or establish a refuge, and has no impact on private landowners taking actions on their land that do not require federal funding or permits.

Related: Jaguars Back in the Southwest USA (2006 post)Big Cats in America (2004)Mountain Lions Returning to the Midwest USA for the First Time in a Century (2012)Backyard Wildlife: Mountain Lion

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Why do Bats Transmit so Many Diseases like Ebola?

Bats are generally wonderful creatures and helpful to us. For example, they eat lots of insects that are annoying (like mosquitoes) and pollinate lots of plants. Of course, they also eat lots of good (for us humans) insects but the insects still seem to be able to fulfill their environmental niches so all is good.

And they are flying mammals which is, of course, cool.

But bats also transmit virus to us, which do us lots of damage. As the video explains as we have intruded into bat territory and chopped down their natural feeding spots we have come into contact with them more. And because bats evolved to be very resilient to virus and they live in large colonies (for easy transmission of the viruses to lots of bats) they can host viruses and survive long enough to infect lots of other bats, and to infect us if we meet them.

I actually didn’t know this (mentioned in the video): most viruses have a very difficult time surviving even with temperatures a bit above the normal human temperature (98 degrees Fahrenheit). Bats, while they fly, have internal temperatures that soar to 104 degrees (40 degrees centigrade) which kills off most viruses, but certain hardy viruses survive. This also explains why we run fevers when we are sick (which then can kill off viruses) – which I am sure I learned at some point but I forgot. But for the bat viruses that strategy doesn’t work.

Bats, of course, are not impervious to disease. In the USA a disease has killed more than 90 percent of the cave bats in Eastern states.

One of the causes of the current ebola outbreak is believed to be people eating bats in West Africa.

Related: Ebola Outbreak in Uganda (2007)A Breakthrough Cure for Ebola (2010)Swine Flu: a Quick Overview (2009)

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Crows can Perform as Well as 7 to 10-year-olds on cause-and-effect Water Displacement Tasks

In Aesop’s fable about the crow and the pitcher, a thirsty bird happens upon a vessel of water, but when he tries to drink from it, he finds the water level out of his reach. Not strong enough to knock over the pitcher, the bird drops pebbles into it — one at a time — until the water level rises enough for him to drink his fill.

Highlighting the value of ingenuity, the fable demonstrates that cognitive ability can often be more effective than brute force. It also characterizes crows as pretty resourceful problem solvers. New research conducted by UC Santa Barbara’s Corina Logan, with her collaborators at the University of Auckland in New Zealand, proves the birds’ intellectual prowess may be more fact than fiction. Her findings, supported by the National Geographic Society/Waitt Grants Program, appear today in the scientific journal PLOS ONE: Modifications to the Aesop’s Fable Paradigm Change New Caledonian Crow Performances.

photo of Corina Logan

Researcher Corina Logan with a great-tailed grackle and a night heron at the Santa Barbara Zoo. The zoo is one of the sites where Logan is gathering data to compare and contrast the cognitive abilities of grackles and New Caledonian crows.
Photo Credit: Sonia Fernandez

Logan is lead author of the paper, which examines causal cognition using a water displacement paradigm. “We showed that crows can discriminate between different volumes of water and that they can pass a modified test that so far only 7- to 10-year-old children have been able to complete successfully. We provide the strongest evidence so far that the birds attend to cause-and-effect relationships by choosing options that displace more water.”

Logan, a junior research fellow at UCSB’s SAGE Center for the Study of the Mind, worked with New Caledonian crows in a set of small aviaries in New Caledonia run by the University of Auckland. “We caught the crows in the wild and brought them into the aviaries, where they habituated in about five days,” she said. Keeping families together, they housed the birds in separate areas of the aviaries for three to five months before releasing them back to the wild.

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Skateboarding Cat

A fun way to start out the week: skateboarding cat.

Related: Friday Fun, Cat Playing Ping PongCat Using the DoorbellCats and Kids with iPads

Goats Excel at Learning and Remembering a Complex Tasks

I like research showing animals using intelligence that seems advanced, for example: Crow Using a Sequence of Three ToolsInsightful Problem Solving in an Asian ElephantBird-brains smarter than your average apeTropical Lizards Can Solve Novel Problems and Remember the SolutionsPigeon Solves Box and Banana Problem.

I also like open access science, and this has both: Goats excel at learning and remembering a highly novel cognitive task

The majority of trained goats (9/12) successfully learned the task quickly; on average, within 12 trials. After intervals of up to 10 months, they solved the task within two minutes, indicating excellent long-term memory. The goats did not learn the task faster after observing a demonstrator than if they did not have that opportunity. This indicates that they learned through individual rather than social learning.”

The individual learning abilities and long-term memory of goats highlighted in our study suggest that domestication has not affected goat physical cognition. However, these cognitive abilities contrast with the apparent lack of social learning, suggesting that relatively intelligent species do not always preferentially learn socially. We propose that goat cognition, and maybe more generally ungulate cognition, is mainly driven by the need to forage efficiently in harsh environments and feed on plants that are difficult to access and to process, more than by the computational demands of sociality. Our results could also explain why goats are so successful at colonizing new environments.

The experiment was done with domesticated goats. I also learned this from the article, which I didn’t know before:

Domestication is known to strongly affect brain size. Consistent reductions in brain size relative to body size, as well as in brain size parts, have occurred in many domestic species.

Related: Orangutan Attempts to Hunt Fish with SpearFriday Fun: Bird Using Bait to FishPhoto of Fish Using a Rock to Open a Clam

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How Wolves Changed the Yellowstone Ecosystem

A great short video explaining the dramatic changes to the Yellowstone ecosystem with the re-introduction of wolves. Even the rivers changed.

Related: Light-harvesting Bacterium Discovered in YellowstoneFishless FutureThe Sea Otter storyYellowstone Youth Conservation Corps Polar Bears Playing with HuskiesCurious Cat travel photos of Yellowstone National Park

Why Don’t All Ant Species Replace Queens in the Colony, Since Some Do

My response to: There are other species of ants that do replace the queen, so why did some species not do this?

Basically the method they evolved copes well with losing the queen. Out of various ways of dealing with having a dominant Queen some may lead to replacement if she dies.

There are lots of examples of method is very effective at creating lots of successful offspring but happens to be less than ideal in some situations. Natural selection is pretty amazing and awesome at creating effective genes but we certainly can look at the results sometimes and see improvements that would be useful.

Likely if losing the queen was very common a good way of dealing with that would be found (or that species would be disadvantaged and at risk). If the queen happens to evolve to being very reliable coping with her death becomes less important. If they produce lots of useful offspring but have a less than ideal method of coping with their home colony losing her it is entirely sensible to imagine that species could flourish.

I would imagine species with queens that had shorter lifespans, that invested more in the home colony, that were less effective at setting up new colonies… would be more likely to have better queen replacement strategies/results.

Related: Ants, Ants, AntsE.O. Wilson: Lord of the AntsAmazonian Ant Species is All Female, Reproduces By CloningRoyal Ant GenesHuge Ant Nest

Another Bee Study Finds CCD is Likely Due to Combination of Factors Including Pesticides

Abstract of open access science paper funded by the United States Department of Agriculture (USDA) Crop Pollination Exposes Honey Bees to Pesticides Which Alters Their Susceptibility to the Gut Pathogen Nosema ceranae:

Recent declines in honey bee populations and increasing demand for insect-pollinated crops raise concerns about pollinator shortages. Pesticide exposure and pathogens may interact to have strong negative effects on managed honey bee colonies. Such findings are of great concern given the large numbers and high levels of pesticides found in honey bee colonies. Thus it is crucial to determine how field-relevant combinations and loads of pesticides affect bee health.

We collected pollen from bee hives in seven major crops to determine 1) what types of pesticides bees are exposed to when rented for pollination of various crops and 2) how field-relevant pesticide blends affect bees’ susceptibility to the gut parasite Nosema ceranae. Our samples represent pollen collected by foragers for use by the colony, and do not necessarily indicate foragers’ roles as pollinators. In blueberry, cranberry, cucumber, pumpkin and watermelon bees collected pollen almost exclusively from weeds and wildflowers during our sampling.

Thus more attention must be paid to how honey bees are exposed to pesticides outside of the field in which they are placed. We detected 35 different pesticides in the sampled pollen, and found high fungicide loads. The insecticides esfenvalerate and phosmet were at a concentration higher than their median lethal dose in at least one pollen sample. While fungicides are typically seen as fairly safe for honey bees, we found an increased probability of Nosema infection in bees that consumed pollen with a higher fungicide load.

Our results highlight a need for research on sub-lethal effects of fungicides and other chemicals that bees placed in an agricultural setting are exposed to.

The attempts to discover the main causes of bee colony deaths and find solutions continues to prove difficult years after the problems became major. The complex interaction of many variables makes it difficult. And special interest groups pushing pesticides and the like, which have seemed to be major contributors to the problem for years, make it even more difficult (by preventing restrictions on potentially damaging pesticide use).

The challenges in determining what is killing bees are similar to the challenges of discovering what practices are damaging human health. The success of studying complex biological interactions (to discover threats to human health) is extremely limited. I am concerned we are far too caviler about using large numbers of interventions (drugs, pesticides, massive antibiotics use in factory farms, pollution…).

Related: Europe Bans Certain Pesticides, USA Just Keeps Looking, Bees Keep DyingGermany Bans Chemicals Linked to Bee Deaths (2008)Virus Found to be One Likely Factor in Bee Colony Colapse Disorder (2007)Study of the Colony Collapse Disorder Continues as Bee Colonies Continue to Disappear

Tropical Lizards Can Solve Novel Problems and Remember the Solutions

Brainy Lizards Pass Tests for Birds

[Duke biologist Manuel Leal] tested the lizards using a wooden block with two wells, one that was empty and one that held a worm but was covered by a cap. Four lizards, two male and two female, passed the test by either biting the cap or bumping it out of the way.

The lizards solved the problem in three fewer attempts than birds need to flip the correct cap and pass the test, Leal said. Birds usually get up to six chances a day, but lizards only get one chance per day because they eat less. In other words, if a lizard makes a mistake, it has to remember how to correct it until the next day

Leal’s experiment “clearly demonstrates” that when faced with a situation the lizards had never experienced, most of them were able to devise a way to solve the problem. Their ability to “unlearn” a behavior, a skill that some mammalian species have difficulty in, is the mark of a cognitively advanced animal, said Jonathan Losos, a biologist at Harvard who was not involved in the study.

To see if the lizards could reverse this association, Leal next placed the worm under the other cap. At first, all the lizards bumped or bit the formerly lucrative blue cap. But after a few mistakes, two of the lizards figured out the trick. “We named these two Plato and Socrates,” Leal said.

It is very cool to see what scientists keep learning about animals.

Related: Insightful Problem Solving in an Asian ElephantBird Using Bread as Bait to Catch FishCrows Transferring Their Understanding to Novel ProblemDolphins Using Tools to Hunt

Scientific Inquiry Process Finds That Komodo Dragons Don’t have a Toxic Bite After All

This articles is another showing the scientific inquiry process at work. Scientists draw conclusions based on the data they have and experiments they do. Then scientists (sometimes the same people that did the original work) seek to confirm or refute the initial conclusions (based on new evidence or just repeating a similar experiment) and may seek to extend those conclusions.

Sometimes the scientists conclude the initial understanding was incorrect, such as with Komodo Dragon’s: Here Be Dragons: The Mythic Bite of the Komodo

for centuries Komodos have been feared by many, with tales of their deadly bite echoing through local cultures. It’s even thought the monstrous lizards may have inspired the mythical beasts that share their name. Their villainous reputation only grew when these fearsome predators were discovered by Europeans in the early twentieth century. But of all the terrible tales told about these dragons, none has been so persistent and pervasive than that of their bite. The mouths of Komodos are said to be laden with deadly bacteria from the decaying corpses they feed on, microbes so disgustingly virulent that the smallest bite lethally infects prey. As the story goes, Komodos have turned oral bacteria into a venom.

It’s a truly fascinating way for an animal to feed — well, truly fascinating in that it’s not true at all.

Related: Video of Young Richard Feynman Talking About Scientific ThinkingNanoparticles With Scorpion Venom Slow Cancer SpreadBig Lizards in Johor BahruNigersaurus