Full Transcript
https://www.youtube.com/watch?v=eyq7h5rHK_k
[00:15] Hi I'm Jane Kay. I'm a senior scientist at Darian Food.
[00:20] And this is a FeedRight video on fiber metabolism.
[00:24] In this video we'll look at the different types of fiber found in feed.
[00:30] What happens when a cow eats fiber and how fiber affects cow production and performance?
[00:37] So what is fiber?
[00:40] Fiber is the term that describes what is in the cell wall of the plant.
[00:45] What gives a plant its structure?
[00:46] It has made up of the two structural carbohydrates, cellulose and hemicellulose, and the indigestible compound lignin.
[00:54] Now lignin is not a carbohydrate, but it combine to the structural carbohydrates making them less accessible to rumen enzymes.
[00:59] Therefore less digestible.
[01:01] The lignin.
[01:04] therefore less digestible the lignin content of the plant increases with age.
[01:06] content of the plant increases with age therefore the plant becomes list adjustable as it matures.
[01:11] now the fiber content of feed as measured in three ways and expressed as a percentage of the dry matter.
[01:16] firstly there is neutral detergent fiber or more commonly tuned in D F.
[01:22] now India if meters the fiber that remains after treating the plant with a neutral detergent.
[01:27] this measures lignin and the structural carbohydrates Hemi cellulose and cellulose.
[01:36] the nearest acid detergent fiber or ADF.
[01:40] now ADF as a measure of the fiber that remains after treating the plant with an acidic detergent.
[01:44] this includes cellulose and lignin but unlike in DF does not include hemi cellulose.
[01:52] atf is often used to indicate the digestibility of the feed.
[01:58] finally there is effective in DF or more commonly referred to as effective fiber.
[02:04] Commonly referred to as effective fiber, now fiber is required by the cow for
[02:07] Now fiber is required by the cow for efficient rumen function, an effective
[02:10] Efficient rumen function, an effective fibre
[02:10] Fibre measures the fiber that is most
[02:12] Measures the fiber that is most effective its stimulating rumination in
[02:15] Effective its stimulating rumination in saliva production. The effect of fiber
[02:17] Saliva production. The effect of fiber generally relates to the top length or
[02:20] Generally relates to the top length or particle size of the fiber components.
[02:23] Particle size of the fiber components. Effect of fiber is difficult to measure
[02:25] Effect of fiber is difficult to measure and certain fees including pastures
[02:28] And certain fees including pastures. However feeds
[02:29] However feeds such as hay and straw a high in effect
[02:31] Such as hay and straw a high in effect of fiber we're a cereal grains alone so
[02:35] Of fiber we're a cereal grains alone so what happens when a cow eats fiber as
[02:38] what happens when a cow eats fiber as already mentioned dietary fiber in
[02:41] Already mentioned dietary fiber in particular effect of fiber that's needed
[02:43] Particular effect of fiber that's needed by the cow to maintain healthy rumen
[02:46] By the cow to maintain healthy rumen function. Once eaten the fiber stimulates
[02:49] Function. Once eaten the fiber stimulates rumination chewing and saliva production.
[02:52] Rumination chewing and saliva production. Saliva contains sodium bicarbonate more
[02:56] Saliva contains sodium bicarbonate more commonly known as baking soda and
[02:57] Commonly known as baking soda and phosphate salts and these help to buffer
[03:00] Phosphate salts and these help to buffer the room and pH and promote the growth
[03:03] The room and pH and promote the growth of room and microbes. Now there are some
[03:05] of room and microbes now there are some differences and the fiber differences and the fiber recommendations depending on the diet.
[03:09] recommendations depending on the diet for diets which concludes a high proportion of starchy feeds such as cereal grains.
[03:14] the recommended minimum fiber level is 27 to 33 percent in DF and 20 percent effective in DF.
[03:24] however for cows grazing only high quality pastures the minimum levels for India are 35% and for effective in DF 17%.
[03:34] there are also differences in the recommended minimum room and pH level.
[03:39] cows grazing good-quality pastures can tolerate a lower room and pH compete with those eating a total mixed ration or a diet high and start without the detrimental effects on rumen function.
[03:51] this is primarily due to the different carbohydrate contents of the two types of diets the different room and microbial populations that digest these carbohydrates and the different waste products that are produced from this digestion.
[04:02] for example when a cow is fed
[04:07] digestion for example when a cow is fed a diet containing a large proportion of a diet containing a large proportion of starch there is preferential digestion of the stat instead of the fiber and propionic acid and lactic acid are produced if there is too much stat in the diet or overdoes introduced too quickly into the diet this causes a drop and room and pH in an increase in electric acid production electic acid reduces fiber digestion and can result in rumen acidosis and lemon itis in contrast when cows are grazing good-quality pasture that contains high levels of structural carbohydrates acetic acid as the main product of digestion now unlike lactic acid acetic acid is not detrimental to room and microbes and does not cause rumen acidosis it is not until room and pH levels fall below five point eight that digestion or rumen function may be reduced in grazing cows in fact adding an extra source of effective fiber and the form of straw or hay to cows grazing
[05:09] the form of straw or hay to cows grazing good-quality pasture can actually decrease performance.
[05:15] the low quality low Emmy straw or hay replaces the higher quality higher Emmy pasture reducing the energy content of the diet because poorly digestible forages such as straw or hay take a longer time to digest in the rumen.
[05:29] they slow down the room and passage rate increase room and fall and consequently can reduce dry matter intake.
[05:36] so in summary fiber consists of lignin and the to structural carbohydrates cellulose and hemicellulose.
[05:47] it can be measured if in DF ADF or effect of fiber a minimum level of fiber and more specifically effect of fiber is required in the diet to promote rumination in saliva production and ensure efficient rumen function.
[06:02] feeds that are high in effect of fiber are poorly digestible and therefore take a longer time to digest in the rumen.
[06:07] if the diet contains high
[06:12] in the rumen if the diet contains high levels of sugar or starch or of effect.
[06:15] levels of sugar or starch or of effect of fiber levels are below requirements.
[06:17] of fiber levels are below requirements supplementary fiber can be added to the.
[06:20] supplementary fiber can be added to the diet to prevent lactic acid production.
[06:22] diet to prevent lactic acid production and to maintain a healthy room and.
[06:24] and to maintain a healthy room and environment however cows grazing.
[06:27] environment however cows grazing good-quality pastures can tolerate lower.
[06:29] good-quality pastures can tolerate lower room and pH levels without the.
[06:32] room and pH levels without the detrimental effects on rumen function of.
[06:35] detrimental effects on rumen function of additional fiber is added to the system.
[06:37] additional fiber is added to the system when it's not needed it will act to slow.
[06:40] when it's not needed it will act to slow down the room and passage rate increase.
[06:42] down the room and passage rate increase rumen fold and can reduce dry matter.
[06:45] rumen fold and can reduce dry matter intake and performance so by the end of.
[06:49] intake and performance so by the end of this video you should be able to name.
[06:51] this video you should be able to name the different types of fiber that are.
[06:53] the different types of fiber that are found in feed know what happens when a.
[06:56] found in feed know what happens when a cow eats five.
[06:57] cow eats five and understand how fiber affects scalp.
[07:00] and understand how fiber affects scalp reduction in performance.
[07:03] reduction in performance.