Record Details
Determination of intake and digestibility of pasture forages using conventional and indicator techniques
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Determination of intake and digestibility of pasture forages using conventional and indicator techniques |
| Names |
Alpan, Suleyman Orhan
(creator) Jones, I. R (advisor) |
| Date Issued | 1964-11-11 (iso8601) |
| Note | Graduation date: 1965 |
| Abstract | Digestibility experiments were carried out with dairy heifers to determine the digestibility of orchard grass, Dactylis glomerata, and also to evaluate the accuracy of various indicator techniques in pasture digestibility experiments. Chromic oxide was used as an external indicator to predict fecal dry matter output in three digestion trials. Cut grass was fed in one of the trials and corn silage in the other two. The internal indicators fecal nitrogen and protein of feed and feces were studied in two of the trials in which one conventional and one grazing trial were involved. The experimental animals consisted of six approximately two year old Holstein heifers and six Jersey heifers of the same ages. All animals were in about the fifth month of pregnancy. In the experiments, five grams of chromic oxide in gelatin capsules were fed to the animals twice a day at 7 A.M. and 4 P.M. Solka-floc, which is a pure cellulose material, was used as a carrier for chromic oxide. Fecal grab samples were collected from the rectum of grazing animals at 6 A.M. and 4 P.M. The chromic oxide recoveries in the feces of the stall fed animals fed orchard grass ranged from 98.4 to 99.2 percent, averaging 98.8 percent. The average difference between the predicted and actual fecal dry matter output was 23.1 g. This magnitude of difference yielded a 1.01 percent error of prediction. However, chromic oxide recoveries for the silage trials were considerably lower, estimated as 79.9 and 74.9 percent for trials III and IV respectively. These low recoveries of chromic oxide resulted in a rather high error of prediction of fecal dry matter output with silages. The average errors of prediction for the grass forage dry matter intakes using fecal nitrogen and protein indigestibility techniques were found to be 1.4 and -6.4 percent, respectively. The respective differences between the average actual and predicted forage dry matter intakes were 86.1 and -405.2 g. Based on the results of this study the fecal nitrogen index technique appears to be superior to the protein indigestibility technique. The digestion coefficients of ether extracts were found to be higher for the conventional trial with pasture than for that of the grazing trial, while the reverse was true for the nitrogen free extracts. The average TDN and digestible energy values for orchard grass dry matter in the conventional trial were found to be 67.1 and 68.0 percent, respectively. The difference in estimations of the TDN and digestible energy values between total collection and fecal nitrogen technique was 0.5 percent, which may be regarded as a reasonable error in digestibility experiments. The TDN and digestible energy values of the grazing trial were slightly higher than that of the conventional trial. The digestible energy determinations were highly correlated with the calculated TDN values. It was concluded that chromic oxide and fecal nitrogen may be used effectively in pasture digestibility experiments. More research is needed to establish their use as reliable indicators with single feed stuffs, such as silages, or when combined in complete rations. |
| Genre | Thesis/Dissertation |
| Topic | Cattle -- Feeding and feeds |
| Identifier | http://hdl.handle.net/1957/48151 |
