1 / 11

Forage Particle Size for Dairy Cows 乳牛的芻料顆粒大小 A. F. Kertz, Ph.D., Dipl ACAN

Forage Particle Size for Dairy Cows 乳牛的芻料顆粒大小 A. F. Kertz, Ph.D., Dipl ACAN. July 2010. Forages for Dairy Cows 乳牛的芻料. Cows cannot digest forage fiber 乳牛不能消化芻料纖維 But microbes in rumen have enzymes that can 但瘤胃中的微生物有可消化纖維的酵素 Cows “ruminate” forage particles and other larger particles

keaira
Download Presentation

Forage Particle Size for Dairy Cows 乳牛的芻料顆粒大小 A. F. Kertz, Ph.D., Dipl ACAN

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Forage Particle Size for Dairy Cows乳牛的芻料顆粒大小A. F. Kertz, Ph.D., Dipl ACAN July 2010

  2. Forages for Dairy Cows乳牛的芻料 • Cows cannot digest forage fiber 乳牛不能消化芻料纖維 • But microbes in rumen have enzymes that can 但瘤胃中的微生物有可消化纖維的酵素 • Cows “ruminate” forage particles and other larger particles 乳牛可反芻芻料顆粒和其他較大的顆粒

  3. Forages for Dairy Cows乳牛的芻料 • Rumination reduces particle size 反芻會減小顆粒大小 • Smaller particles have more surface area to increase fermentation of forage 較小的顆粒有較多的表面積，以增加芻料的發酵 • Larger forage particles form “mat” on top of rumen contents 在瘤胃內容物的上層，較大的芻料顆粒形成“墊層“

  4. Forages for Dairy Cows乳牛的芻料 • “mat” helps trap particles so that they are fermented more in rumen 　“墊層”有助於留住顆粒，因此顆粒在瘤胃中有較佳的發酵 • “mat” slows flow out of rumen so digestibility is increased “墊層” 減慢離開瘤胃的流量，因而消化率增加 • “mat” is decreased with low forage level and smaller forage particle size “墊層”隨著低芻料水平和較小的芻料顆粒而減少

  5. Physical Nutrition 生理營養 Key to optimised ration digestibility is rumen function 　　最佳化的飼糧消化率其關鍵是瘤胃的功能 Physical Fiber optimises rumen function through correct ration presentation 經由給予正確的飼糧，物理纖維使瘤胃有最佳的功能 • Increased concentrates leads to:　增加精料導致： • More small particles　較多小顆粒 • Increased microbial activity　增加微生物活性 • Increased acid production　 增加酸產量 • Reduced fibre digestion　減少纖維消化 • Increased health issues　增加健康問題 • Reduced feed efficiency (FCE)　降低飼料效率 • Shorter fibre leads to:　較短的纖維導致： • Dense fibre mat　緊密的纖維墊層 • Reduced rumen contractions　降低瘤胃收縮 • Reduced cud chewing　減少反芻咀嚼 • Increased passage of smaller particles 　 增加較小顆粒的通過 Keenan TMR Mixers

  6. Forage Particle Size and impact upon cudding (rumination) 芻料顆粒大小以及對於反芻的衝擊 **Lower milk fat, less rumination, and lower pH all indicate marginal acidosis which will lead to lower intake, milk production and health problems. 較低的乳脂、較少反芻，以及較低的pH皆顯示瀕臨酸症，將導致較低的採食量、乳量和健康的問題。 Keenan TMR Mixers

  7. Digestibility Varies消化率的變異 Firkins et al. J. Anim. Sci. 79(E. Suppl.):E218–E238, 2001. • Average digestibility of ground corn = 80% but variability causes range from 64 to 96 % 　玉米粉的平均消化率= 80% 　但變異的範圍從 64 至 96 % • That means 20% is not digested　也就是有20% 是未消化的 • But dependent on corn color (varies), you may not see undigested corn in the manure 　但要看玉米的顏色（變動），你可能看不到糞便中未消化的玉米 • Main factors are:　主要因素為： • accuracy in measuring digestibility　測定消化率的準確性 • particle size of corn　玉米的顆粒大小 • hybrid　雜交品種

  8. Total Palmitic C16:0 Stearic C18:0 C18:1 Oleic Linoleic C18:2 Linolenic C18:3 Fatty Acid Digestibility　脂肪酸消化率 Summary of 9 Dairy Cow Studies *Fat has 2.25 more energy than protein and carbohydrates. Grummer and Rabelo (1999)

  9. Alfalfa Hay—Chopped Particle Size • 1/3 alfalfa particles less than 8 mm—mostly leaves • which have most of protein and calcium • 1/3苜蓿顆粒小於8毫米—大部分是葉子，含有很多的蛋白質和鈣 • 3/4 barley silage particles18 to 8 mm—wetter and less brittle than alfalfa hay • 3/4大麥青貯料顆粒為 18 至 8 毫米—相較於苜蓿乾草較濕 • 潤且較不易碎 • Distillers dried grains all small particles 蒸餾乾燥穀物皆為小顆粒 Zhang et al. J. Dairy Sci. 93:3243-5253, 2010.

  10. Particle Size Impact顆粒大小的影響 • Alfalfa Hay　苜蓿乾草 • Loses forage value as is chopped　當其切短即損失芻料價值 • Brittle so small stems and leaves shatter and may be lost to wind and settling out before in TMR 易碎因此小莖和葉片會斷落，可能在開始製成TMR前隨風散失和沉底 • Wet Ensiled Forages　濕的青貯料 • Are flexible so do not shatter like alfalfa hay 柔軟的，因而不會像苜蓿乾草一般會斷落 • Provide moisture to TMR and acidity for palatability and minimizes dryness　提供水分給TMR，且酸度能增加適口性，另外避免乾燥Ground grains and by-products　磨碎穀物和副產物 • Most have no particle size effects　大多沒有顆粒大小的作用

  11. Recommendations 建議 • Grind/chop forage in TMR mixer so do not lose smaller particles—especially with alfalfa 在TMR混合器機中磨碎/切短芻料，因而不會損失較小的顆粒—特別是在苜蓿 • Do NOT over chop. 6-7cm in length is desirable • 不要過度切短。長度要有6-7公分 • Characteristics of TMR mixerTMR 混合機的特性 • Time and sequence of mixing　混合的時間和順序 • Add water if all dry ingredients—up to 50% in Arizona study—very low humidity 　需加入水，假使所有原料皆為乾的—在Arizona的研究指出加到50%—溼度很低 • Particle size affects intake, digestibility, milk production and fat/protein components 　顆粒大小會影響採食、消化率、乳量和乳脂/乳蛋白成分 • Avoid “bare bunk disease”, have some leftovers ~2%, can feed to larger heifers 避免飼槽清空疾病，要有一些剩料約2%，剩料可餵給較大的女牛

More Related