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Titolo:
EFFECT OF LOCK UP AND HARVEST DATES ON DAIRY PASTURE DRY-MATTER YIELDAND QUALITY FOR SILAGE IN SOUTH-WESTERN VICTORIA
Autore:
JACOBS JL; RIGBY SE; MCKENZIE FR; WARD GN; KEARNEY G;
Indirizzi:
DEPT NAT RESOURCES & ENVIRONM,78 HENNA ST WARRNAMBOOL VIC 3280 AUSTRALIA DEPT NAT RESOURCES & ENVIRONM,PASTORAL & VET RES INST HAMILTON VIC 3300 AUSTRALIA
Titolo Testata:
Australian journal of experimental agriculture
fascicolo: 2, volume: 38, anno: 1998,
pagine: 131 - 138
SICI:
0816-1089(1998)38:2<131:EOLUAH>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
GRAZING INTENSITY; MILK-PRODUCTION; DIGESTIBILITY; HERBAGE; COWS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
23
Recensione:
Indirizzi per estratti:
Citazione:
J.L. Jacobs et al., "EFFECT OF LOCK UP AND HARVEST DATES ON DAIRY PASTURE DRY-MATTER YIELDAND QUALITY FOR SILAGE IN SOUTH-WESTERN VICTORIA", Australian journal of experimental agriculture, 38(2), 1998, pp. 131-138

Abstract

At 2 sites in south-western Victoria, 132 plots of predominantly perennial ryegrass pasture were randomly allocated, within 4 replicate blocks, to each of 3 lock up dates (L1, L2, L3) by 12, 12 or 9 harvest times. Harvesting commenced 2 weeks after initial treatment lock up withL1 and L2 being harvested 12 times (weekly intervals) and L3, 9 times. Lock up dates were 15 August (L1), 5 September (L2) and 26 September(L3) at site 1 and 17 August (L1), 7 September (L2) and 28 September (L3) at site 2. For each treatment and harvest date, dry matter yield and botanical composition were determined and samples of total pastureand the ryegrass fraction were collected and assessed for dry matter digestibility, crude protein and neutral detergent fibre. Dry matter yield was measured from the start of L1 (site 1, 15 August; site 2, 17 August) until the final harvest date of L3 (site 1, 12 December; site 2, 14 December). At site 1, L3 produced higher dry matter yields than L1 and L2 at comparable lengths of lock up time, whilst there were no differences at site 2. Over the total experimental period (site 1, 15 August-12 December; site 2, 17 August-14 December) there were no differences in total dry matter yield (t/ha) between treatments at either site (site 1-L1 5.79, L2 6.43, L3 5.94; site 2-L1 6.68, L2 5.07, L3 5.73). Treatments had little effect on botanical composition at either site when compared at the same time after lock up, both during the harvesting period or in the subsequent autumn. Pasture metabolisable energyand crude protein all declined with increasing length of lock up whilst neutral detergent fibre content increased, changes which were similar for both the total pasture and the ryegrass fraction. The metabolisable energy of pasture in L1 and L2 was higher than that of L3 at least until week 8 at both sites. Initial crude protein values were higherfor L1 and L2 than for L3 at site 1, whilst at site 2, L1 had higher values than either L2 or L3. Although longer lock up periods produced more herbage, if conserving forage is to be an integral component of managing surplus spring pasture, then dairy farmers should aim to produce high quality pasture fbr forage conservation. This will be achievedthrough shorter lock up periods and harvesting pasture no later than early ear emergence in the ryegrass fraction of the sward. This management will reduce dry matter yields, but allow more flexibility for maintaining intensive grazing practices through the spring period. The decision about when to lock up pasture will depend on both plant growth rates and animal feed requirements.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 00:59:37