Thesis (MScAgric)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The objectives of this study were to determine the effects of supplementing oat silage
(OS) with lucerne (LH) and oat hay (OH) on the production performance of lactating
Jersey cows, as well as comparing the ruminal degradability of LH, OH and OS III
Holstein and Jersey cows receiving a high forage diet and a high concentrate diet.
In the first trial, five diets containing different combinations of OS and LH together with
concentrate mixtures providing 26, 23, 20, 17 and 14% crude protein (CP) were fed to
lactating Jersey cows. Lucerne hay was fed at 0, 2, 4, 6, and 8 kg DM/day while OS was
fed ad libitum. Cows receiving only OS as a forage source had a lower (P<0.05) dry
matter (DM) intake and produced less milk protein (P<0.05). Milk and fat yields as well
as milk urea nitrogen (MUN) levels did not differ (P>0.05) between treatments.
In the second trial, OS was fed with OH and a concentrate mixture containing 26% CP to
lactating Jersey cows. Oat hay was fed at 0, 2, 4, 6, and 8 kg DMiday while OS was fed
ad libitum. Cows that received OS together with 4 and 6kg OH, respectively had higher
(P<0.05) DM intakes. Milk, fat, and protein yields as well as MUN levels did not differ (P>O.05) between treatments.
The ruminal degradability of LH, OH and OS in Holstein and Jersey cows receiving (i) a
high forage and (ii) a high concentrate diet was determined. The two breeds were also
compared in terms of rumen pH levels, volatile fatty acids (VF A) and rumen ammonia
nitrogen (NH3-N) concentrations as affected by time after feeding. The ruminal
degradability of freeze dried (FD), oven dried (OD) and fresh oat silage (FS) in Jersey
cows receiving a high forage diet was also determined.
The ruminal DM, CP and NDF degradability of LH was higher (P<O.05) than that of OH
and OS in both Holstein and Jersey cows when they were fed either a high forage or a
high concentrate diet. When cows were fed a high forage diet, the effective DM
degradability of OS was higher (P<O.05) in Holsteins although the CP degradation rates
of LH and OH were higher (P<O.05) in Jerseys. When they were fed a high concentrate
diet, Jerseys had higher (P<O.05) effective DM and NDF degradabilities and higher
(P<O.05) DM and NDF degradation rates in LH while Holsteins had higher (P<O.05)
effective CP degradability levels than Jerseys in OS.
After feeding a high forage diet, pH levels declined while VFA and NH3-N
concentrations increased (P<O.05) in both breeds. Jerseys had higher rumen pH, lower
(P<O.05) VFA and lower NH3-N concentrations than Holsteins throughout the study.
When cows were fed a high concentrate diet, Jerseys had higher (P<O.05) pH than
Holsteins. A post-feeding decline (P<O.05) in pH was observed in both breeds.
Fresh oat silage had a lower (P<O.05) effective degradability and degradation rates for
DM, CP and NDF in comparison to FD and OD oat silage. The DM, CP and NDF
degradation rates, as well as effective NDF degradability were higher (P<O.05) for FD
silage, but effective DM and CP degradabilities were higher (P<O.05) for OD oat silage.
It was concluded that on an oat silage diet, lactating Jersey cows should receive a
minimum of 2kg LH or 4 to 6kg oat hay together with ad libitum OS to improve DM intake. When cows were fed a high concentrate diet, the ruminal degradability appeared
to be superior in Jerseys than Holsteins. Jerseys also had higher rumen pH levels lower
VFA and NH3-N concentrations than Holsteins. Feeding interval affects the rumen
environment, pH declines while VF A and NH3-N concentrations increased. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van die aanvulling van hawerkuilvoer met
lusemhooi (LH) en hawerhooi (HH) op die melkproduksie van Jerseykoeie te bepaal.
Hiermee saam is die rumen degradeerbaarheid van hawerkuilvoer en lusemhooi
ondersoek in Jersey en Holsteinkoeie wat 'n hoe-ruvoer en 'n hoe-kragvoer gebaseerde
dieet ontvang het.
In die eerste proef is vyf diete met verskillende peile van hawerkuilvoer en lusernhooi
saam met kragvoere van verskillende ruproteienpeile (26, 23, 20, 17 en 14% RP) aan 10
lakterende Jerseykoeie gevoer. Hawerkuilvoer is ad libitum voorsien en lusemhooi is
teen vlakke van 0, 2, 4,6 en Skg droemateriaal (DM) per dag gevoer. Die DM-inname en
melkproteienproduksie van koeie wat hawerkuilvoer as die enigste ruvoerbron ontvang
het, was laer (P<0.05) as ander ruvoerkombinasies. Die melk- en vetproduksie, asook
melk-ureumstikstofpeile het nie tussen behandelings verskil nie (P>0.05).
In die tweede proef is hawerkuilvoer saam met hawerhooi (soortgelyk as Proef 1) gevoer.
Die kragvoerkomponent van al die ruvoerkombinasies het 26% RP bevat. Die koeie wat
hawerkuilvoer en 4 of 6kg hawerhooi as ruvoere ontvang het, het hoer (P<O.05)
droemateriaalinnames gehad. Melk, vet en proteienproduksie asook melk-ureumstikstofpeile
het nie tussen ruvoerkombinasies verskil nie (P>O.05).
Die rumendegradeerbaarheid van lusemhooi, hawerhooi en hawerkuilvoer is bepaal in
Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en (ii) 'n hoe kragvoerdieet ontvang het.
Die rumen pH, vlugtige vetsuur en rumen-ammoniakkonsentrasies, soos beinvloed deur
tyd na voeding, is ook tussen rasse vergelyk. Die rumendegradeerbaarheid van vars,
oondgedroogde en vriesgedroogde hawerkuilvoer is ook bepaal.
Die rumen DM, RP en NDF degradeerbaarhede van lusemhooi was hoer (P<O.05) as by
hawerhooi en hawerkuilvoer in beide Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en
(ii) 'n hoe kragvoerdieet ontvang het. Op 'n hoe ruvoerdieet, was effektiewe DM
degradeerbaarheid van hawerkuilvoer by Holsteins hoer (P<O.05) as by Jerseys.
Jerseykoeie het egter 'n hoer (P<O.05) RP degradeerbaarheidstempo van lusemhooi en
hawerhooi gehad.
Jerseykoeie op 'n hoe kragvoerdieet, het hoer (P<O.05) effektiewe DM en NDF
degradeerbaarhede getoon. Hulle het egter 'n laer (P<O.05) effektiewe ruprotein (RP)
degradeerbaarheid by hawerkuilvoer as Friese gehad. Jerseykoeie op lusemhooi het ook
'n hoer (P<O.05) DM en NDF degradeerbaarheidstempo getoon.
Jerseykoeie wat 'n hoe ruvoerdieet ontvang het, het 'n hoer (P<O.05) rumen- pH en laer
(P<O.05) vlugtige vetsuur- en rumen-ammoniak konsentrasies as Holsteinkoeie gehad.
Jerseykoeie wat 'n hoe kragvoerdieet ontvang het, het ook 'n hoer (P<O.05) rumen- pH as
Holsteinkoeie gehad. By al die koeie is gevind dat rumen- pH na voeding afgeneem het
(P<O.05). Vlugtige vetsuur- en rumen-ammoniakkonsentrasies was laag voor voeding en
het daama toegeneem (P<O.05).
Vars hawerkuilvoer het laer (P<O.05) effektiewe DM, RP en NDF degradeerbaarhede en
degradeerbaarheidstempo's as oond- en vriesgedroogde hawerkuilvoer gehad. Die
vriesgedroogde kuilvoer het hoer (P<O.05) DM, RP en NDF degradeerbaarheidstempo's
sowel as effektiewe NDF degradeerbaarhede gehad. Oondgedroogde kuilvoer het
daarinteen hoer (P<O.05) effektiewe DM en RP degradeerbaarhede gehad.
Die gevolgtrekking is gemaak dat lakterende Jerseykoeie ten minste 2kg lusemhooi of 4-
6kg hawerhooi per dag moet ontvang wanneer hulle hawerkuilvoer as ruvoerbron
ontvang. Op 'n hoe kragvoerdieet, het dit gebleik dat die rumendegradeerbaarheid van
vesel by Jerseys beter is as by Holsteins. Die rumen- pH is hoog voor voeding, maar dit
neem af nadat die koeie gevreet het. Die rumen- pH van Jerseys was hoer as by
Holsteins. Die vlugtige vetsure en rumen-ammoniakkonsentrasies blyk laag te wees voor
voeding en neem daama toe. Konsentrasies was hoer by Holstein as by Jerseys.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52970 |
| Date | 03 1900 |
| Creators | Bangani, N. M. (Noluvuyo Muriel) |
| Contributors | Cruywagen, C. W., Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 137 p : ill. |
| Rights | Stellenbosch University |
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