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The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions
Thesis (PhDAgric (Animal Sciences))--Stellenbosch University, 2011.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2011
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| _version_ | 1867613858383790080 |
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| access_status_str | Open Access |
| author | Swiegers, Johannes Pieter |
| author2 | Cruywagen, C. W. |
| author_browse | Cruywagen, C. W. Swiegers, Johannes Pieter |
| author_facet | Cruywagen, C. W. Swiegers, Johannes Pieter |
| author_sort | Swiegers, Johannes Pieter |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDAgric (Animal Sciences))--Stellenbosch University, 2011. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/18096 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:42:49.487Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2011 |
| publishDateRange | 2011 |
| publishDateSort | 2011 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/18096 The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions Swiegers, Johannes Pieter Cruywagen, C. W. Hall, M. B. Tedeschi, L. Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences. Dairy cattle -- Feeding and feeds Dairy cattle -- Nutrition Theses -- Agriculture Dissertations -- Agriculture Thesis (PhDAgric (Animal Sciences))--Stellenbosch University, 2011. ENGLISH ABSTRACT: A series of experiments were conducted to determine the effect of the replacement of oat silage by wheat straw in low forage diets for high producing dairy cows. In the first trial, 28 multiparous Holsteins were randomly assigned to two dietary treatments, namely silage and straw after completing a covariate period coinciding with the first 40 days of lactation and remained on these diets for the remainder of experimental period from 41 to 252 days. In order to evaluate the effect of substitution during different stages of lactation, the experimental period was divided into four phases. Diets were formulated to support similar levels of milk for both treatment groups and for all phases. The substitution of oat silage by wheat straw had a negative effect on dry matter intake, milk production and composition, as well as on feed and nitrogen efficiency, but had no effect on body weight and body condition. A rumen fermentation trial was also done, where six multiparous cannulated cows were randomly allocated in a changeover design to the same dietary treatments used in the animal performance trial. Despite a relatively low peNDF content and high NFC content of the diets, the mean rumen pH and time spent below pH 5.8 indicated that cows were actually not subjected to subclinical rumen acidosis, probably due to effective chewing activity. Forage source had no significant effect on rumen fermentation end products or mean daily rumen pH. However, the time spent below pH 5.8 was significantly lower for cows in the silage treatment than for those in the straw treatment, which could be related to a longer chewing time and more effective chewing activity that was observed on the straw treatment. Cows on the straw treatment sorted less against the medium sized particles, which was not expected, since straw inclusion is normally associated with a higher degree of sorting. In a third experiment, the effect of the replacement of silage by wheat straw was evaluated in terms of pre and postpartum animal performance. Dry cow diets were formulated with the objective to restrict intake, thus preventing cows from consuming metabolizable energy in excess of their requirements. Both treatments were successful in controlling intake and the replacement of oat silage by wheat straw in dry cow diets had no apprent effect on postpartum animal performance. Using the data from the lactation experiment, the adequacy of the CPM Dairy model to predict animal performance from low forage diets was also evaluated. The model was highly accurate in predicting adjusted milk production of cows consuming oat silage as basal forage, with a mean bias of only 0.05 kg milk/d, but it overpredicted milk production of cows receiving diets with wheat straw as the sole forage source, with a mean bias overprediction of 2.3 kg milk per day during the corresponding period of positive energy balance. Overprediction of energy balance from straw was confirmed in the dry cow experiment where a statistical analysis of the residuals between predicted and actual body condition score change indicated an overprediction on the straw treatment. AFRIKAANSE OPSOMMING: Die invloed van die vervanging van hawerkuilvoer deur koringstrooi in diëte vir hoogproduserende melkkoeie is in ‘n reeks proewe nagegaan. In die eerste proef is 28 volwasse Holsteinkoeie ewekansig aan ‘n kuilvoer- of strooigebaseerde behandeling toegeken na die voltooiing van ‘n kovariaatperiode van 40 dae. Ten einde die invloed van die behandeling tydens verskillende stadia van laktasie te evalueer, is die proefperiode in vier fases verdeel. Diëte is geformuleer om vergelykbare melkproduksies vir beide behandelings tydens al die fases te ondersteun. Vervanging van hawerkuilvoer deur koringstrooi het ‘n negatiewe invloed op droëmateriaalinname, melkproduksie, melksamestelling, voeromset en stikstofbenutting gehad, maar geen invloed op ligaamsmassa- en kondisieverandering nie. In ‘n rumenfermentasieproef is ses volwasse, gekannuleerde Holsteinkoeie in ‘n omswaai-ontwerp aan twee diëte, soortgelyk aan dié wat tydens die laktasieproef gebruik is, in toegewys. Ten spyte van ‘n relatief lae peNDF-inhoud en ‘n relatief hoë NFC-inhoud van die diëte was daar, te oordeel aan die gemiddelde rumen pH en tyd waartydens die rumen pH onder 5.8 was, geen aanduiding van subkliniese rumenasidose nie, waarskynlik as gevolg van ‘n langer kou-tyd en meer doeltreffende kouaktiwiteit. Ruvoerbron het skynbaar ook geen invloed op rumenfermentasie-eindprodukte en gemiddelde rumen pH gehad nie. Die periode waartydens rumen pH laer as 5.8 was, was egter korter vir koeie in die kuilvoerbehandeling as vir dié in die strooibehandeling. Dit kan waarskynlik aan meer doeltreffende herkou-aktiwiteit toegeskryf word. Aangesien strooiinsluiting in herkouerdiëte normaalweg met ‘n groter mate van voerseleksie geassosieer word, was die kleiner mate van seleksie teen mediumgrootte partikels met die strooibehandeling verrassend. In ‘n derde proef is die invloed van van die vervanging van kuilvoer met koringstrooi in terme van pre- en postpartum diereprestasie ondersoek. Droëkoeidiëte is geformuleer met die doel om inname te beperk en koeie sodoende te verhoed om meer metaboliseerbare energie in te neem as wat hulle benodig. Albei behandelings was doeltreffend om inname te beheer en die vervanging van hawerkuilvoer met koringstrooi het geen invloed op postpartum diereprestasie gehad nie. Deur van die data van die laktasieproef gebruik te maak, is die toereikendheid van die CPM Dairy model om diereprestasie vanaf lae ruvoerdiëte te voorspel, ook bepaal. Die model was hoogs akkuraat in die voorspelling van melkproduksie in die geval van die kuilvoerbehandeling, maar dit het melkroduksie met 2.3 kg/dag oorskat in die geval van die koringstrooibehandeling. Hierdie oorberaming van energiebalans is tydens die droëkoeiproef bevestig. Doctoral 2011-11-23T11:35:29Z 2011-12-06T08:36:30Z 2012-11-23T22:10:03Z 2011-12 Thesis http://hdl.handle.net/10019.1/18096 en_ZA Stellenbosch University xi, 160 p. : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Dairy cattle -- Feeding and feeds Dairy cattle -- Nutrition Theses -- Agriculture Dissertations -- Agriculture Swiegers, Johannes Pieter The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions |
| title | The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions |
| title_full | The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions |
| title_fullStr | The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions |
| title_full_unstemmed | The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions |
| title_short | The effect of oat silage replacement with wheat straw in dairy cow diets on animal performance, rumen fermentation and adequacy of CPM dairy model predictions |
| title_sort | effect of oat silage replacement with wheat straw in dairy cow diets on animal performance rumen fermentation and adequacy of cpm dairy model predictions |
| topic | Dairy cattle -- Feeding and feeds Dairy cattle -- Nutrition Theses -- Agriculture Dissertations -- Agriculture |
| url | http://hdl.handle.net/10019.1/18096 |
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