A Study On Parameters In The Measurement Of Nutrients Ruminal Degradability Of Feedstuffs For Goats

The present study consists of there parts. The first part used Cr-marked feedsto study the effects of dry matter intake (DMI), concentrate level in completepullet, NDF% or unit weight of Cr-marked feeds on the k value. The secondpart, degradabilities of more than 40 feedstuffs were evaluated by in saccomethod. The effect of grinding mesh number of feedstuffs on degradabilitywas studied at the same time. The third part was to study the effects ofplanting density and harvest time on degradability of four pastures.Part 1: The test animal was three six-month old native castrated white goatswith average live weight of 20kg±1kg which were fitted with permanentruminal fistulae at least one month before experiments. The diets werecomposed of four complete pullet with different concentrate level (20%,28%,36%,44%) and one chopped peanut stalk. The experiment usedCr-marked feeds to study effects of DMI, concentrate level in complete pullet,NDF% or unit weight of Cr-marked feedstuffs on k. The results indicated that:1. The DMI had a significant effect on ruminal out flow (P<0.01). DMI had asignificant positive correlation on the k value(P<0.01).2.Concentrate level had an insignificant effect on the k value (P>0.05).Cr-marked feed had a significant effect on the k value (P<0.01). The mutualeffect of the two on the k value was significant (P<0.01).3.The k value had a significant relation with the NDF and unit weight ofCr-marked feed (P<0.01).4.When fed with complete pullet, the k value can be predict with concentratelevel (X1,%) and unit weight (X2, g/L), the function is: k=2.46-0.012X1+0.003X2 (r=0.97)Part 2: More than 40 feedstuffs were evaluated by in sacco method with threesame goats as above. Factors of ruminal degradability, such as grinding mesh 3刘美:山羊饲料养分瘤胃降解规律的研究number were studied at the same time. The result indicated that:1. The NDF and ADF of roughage had relations with ordinary nutrient asfollows: NDF=43.07-0.0336CP-2.557CEE+0.730CF(r=0.95,n=14) ADF=19.71-0.93CEE+0.80CF(r=0.88,n=14)2.The effective CPD offeedstuffs from high to low were: milling byproducts(73.43)>beans(66.97)>meal-extract(61.02)>hays(60.93)>cereals(50.96>distillers(47.42)>stalks(42.72)>animal by products(18.83).3. To roughage, DMD between CF, NDF, ADF, ADL (P<0.05) were:DMD=84.16+0.42CF-0.93NDF+0.19ADF-1.44ADL (r=0.84,n=15)To beans, CPD and nutrients had relations as follows (n=7):DMD=42.77+0.81CP+1.1CEE-9.96CF-7.27CA(r=0.92)CPD=52.15-0.234CP+1.14CEE-7.38CF-11.73CA(r=0.95)4.Grinding mesh had a significant effect on measure of degradability (P<0.01).5.Concentrate level in pullet had insignificant effect on effective CPdegradability (P>0.05).6.To most feedstuff, the value of DMD and OMD is near and DMD>OMD.The value of OMD/DMD is stable.Part 3: This experiment used two white goats to study the effects of plantingdensity on degradability of Beifeicao (B) and Wancao2#(W) and their silage,the effects of cutting times and growing time on DMD of B and W and Reosint.The DMD of Nongda108 is compared at the same time. The results as follows:1. The DMD and CPD of B were increased with the increase of density(P>0.05). When planting at 17,000/666.7m2, W had highest DMD and CPD.The DMD between B and W was insignificant (P>0.05). The CPD of W wasmuch higher than that of B(P<0.01). Ensilaging can improve DMD of B andW significantly (P<0.01). The difference between DMD of three density of Bsilage was insignificant(P>0.05). W silage had a highest DMD when plantingat 9000/666.7m2(P<0.01).2. With the increase of growing time, DMD of B and W reduced (P<0.01).Effects of cutting times on DMD of B was insignificant(P>0.05). DMD of Wwas reduce with increasing of cutting times(P<0.01). Effects of cutting timesand growing time on DMD of Reosinte were insignificant(P>0.05).3. The DMD of Nongda108 was higher than Reosint(P<0.01). The DMD ofReosint was higher...