Morfološki razvoj ter spreminjanje količine in kakovosti pridelka mnogocvetne ljuljke (Lolium multiflorum Lam.)

Kopač, Primož (avtor), Čop, Jurče (mentor), Verbič, Jože (komentor)

Namen raziskave je bil določiti poteke pridelka, razvojne faze in kakovostnih kazalcev zelinja mnogocvetne ljuljke (Lolium multiflorum Lam.) ter njihove medsebojne povezave med prvima dvema rastnima ciklusoma (RC1 in RC2). Poljski poskus smo zasnovali v split-plot obliki z dvema ponovitvama. Pri vsakem rastnem ciklusu smo opravili 12 meritev s petdnevnimi razmiki. Srednjo razvojno fazo sestoja (SFT) smo določali po Sandersonu (TEAS lestvica), vsebnost neto energije za laktacijo (NEL) pa na podlagi kemične sestave vzorcev zelinja in plina, ki se razvije pri inkubaciji vzorcev z vampovim sokom. Ugotovili smo, da se je pri RC1 SFT povečevala hitreje kot pri RC2 (0,342 proti 0,737 na dan), vsebnosti NEL in surovih beljakovin (SB) pa sta se pri RC1 zmanjševali počasneje (-0,034 MJ in -2,84 g na kg sušine na dan) kot pri RC2 (-0,047 MJ in -4,96 g na kg sušine na dan). Pri enaki SFT je vsebovala krma RC1 v povprečju za 0,36 MJ na kg sušine več NEL kot krma RC2. Pridelek sušine se je med razvojem mnogocvetne ljuljke povečeval in je bil pri RC1 ob enaki SFT večji kot pri RC2. Na podlagi rezultatov smo zaključili, da je krma RC1 primerna za košnjo pri SFT 9 ali 10. Pri tej SFT pridelek sušine presega 3,5 t na ha, vsebnost NEL pa 6,7 MJ na kg sušine. Pri RC2 je bil pridelek 3 t sušine na ha presežen šele pri SFT 16, ko se je vsebnost NEL že zmanjšala pod 5,8 MJ na kg sušine. Videti je, da je ciljna vsebnost 6,0 MJ NEL na kg sušine za RC2 nedosegljiva, razen pri zelo majhnih pridelkih (< 2 t sušine na ha).

• Jezik: Slovenski jezik
• Ključne besede: prehrana živali, krma, mnogocvetna ljuljka, morfološki razvoj, pridelek, kakovost
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2019
• PID: 20.500.12556/RUL-107613
• COBISS.SI-ID: 4212104
• Datum objave v RUL: 07.05.2019

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Morphological development and changes of the quantity and quality of Italian ryegrass (Lolium multiflorum Lam.) yield

Izvleček

The aim of the study was to determine the changes in dry matter yield, development stages and quality parameters of Italian ryegrass (Lolium multiflorum Lam.) herbage and their interrelationships during the first two growth cycles (GC1 and GC2). The field experiment was carried out in a split-plot design with two replicates. For each growth cycle 12 measurements in five-day intervals were done. The mean stage by weight (MSW) was determined according to Sanderson (TEAS scale), and the concentration of net energy for lactation (NEL) based on the chemical composition of herbage samples and the gas released during the incubation of samples with the rumen liquor. It was found that in GC1, MSW increased faster than in GC2 (0.342 vs. 0.737 per day), while NEL and crude protein (CP) concentrations decreased more slowly in GC1 (-0.034 MJ and -2.84 g per kg of dry matter per day) compared to GC2 (-0.047 MJ and -4.96 g per kg of dry matter per day). At the same MSW value, forage of GC1 contained on average 0.36 MJ per kg of dry mater more NEL than GC2 forage. Dry matter yield of Italian ryegrass increased during the stand development and was at the same MSW higher in GC1 than in GC2. Based on the results it was concluded that GC1 forage is suitable for harvesting at MSW 9 or 10. At this MSW dry matter yield exceeded 3.5 t per ha and the NEL concentration was above 6.7 MJ per kg of dry matter. In the GC2, the yield of 3 t dry matter per hectare was only exceeded at SFT 16 when the NEL concentration had already decreased below 5.8 MJ per kg of dry matter. It seems that for GC2, the target value of 6.0 MJ NEL per kg of dry matter is unachievable, except for very small forage yields (< 2 t of dry matter per ha).

• Ključne besede: animal nutrition, feed, Italian ryegrass, morphological development, herbage yield, quality