Fermentation characteristics and nutritional value of Opuntia ficus-indica var. Fuscicaulis cladode silage

Abstract

English: A laboratory study was under taken to investigate the nutritional value of different Opuntia varieties from chemical analysis. One year old cladodes from six different varieties of Opuntia ficus-indica namely Castello, Chicco, Fusicaulis, Montery, Morado and Rubasta were randomly harvested in five replicates. The highest (P<0.05) average dry matter (DM) content was observed for the Chicco variety and was the average for all varieties generally low (9.13%). There were no significant difference (P>0.05) in ash content. Significant (P<0.05)differences among varieties were recorded for crude protein (CP) (3.7 to 8.1%), acid detergent fibre (ADF) (13.6 to 17.4%), neutral detergent fibre (NDF) (19.9 to 38.5%), cellulose (2.4 to 14.8%), hemicellulose (4.5 to 12.7%), lignin (2.51 to 21.5%), non fibre carbohydrates (NFC) (33.4 to 48.6%), ether extract (EE) (1.9 to 2.4%). The average mineral composition were as follows, phosphorus (P) 0.18%, potassium (K) 3.02%, calcium (Ca) 2.3%, magnesium (Mg) 3.6% and sodium (Na) 0.04%. It was concluded that in general cladodes could be classified as a high moisture energy source with an energy level between that of roughages and concentrates with a low CP and high Mg, K and Ca content. In a second study the influence of dry matter (7.12 to 27.6 %) and molasses (0 to 24%) content on the fermentation characteristics of Fusicaulis cladode silage was investigated. One year old cladodes was ensiled in three litre square plastic bottles (six replicates). A higher DM content were characterized with a lower (P<0.05) ADF, NDF, CP and EE content. The inclusion of molasses resulted in a lower (P<0.05) ADF, NDF and EE content. An increased (P<0.05) acetic acid (AA) content in Fusicaulis silage was observed as the level of DM and molasses increased. A higher silage DM content resulted in a lower (P<0.05) propionic acid (PA) and butyric acid (BA) content. No significant (P>0.05) influence of molasses on PA and BA occurred. Lactic acid (LA) content and pH of cladode silage was increased (P<0.05) by higher DM and molasses levels. It was concluded that the content of cladode silage could have detrimental effect on intake and animal performance. In a third study, the effect of DM (35.5 and 37.4%) and molasses (0 and 24%) content of ensiled cladodes on dry matter intake (DMI) and apparent digestibility by sheep was investigated. Twentyfour merino wethers were randomly divided into 4 groups of 6 each. No statistical significant (P>0.05) influence of DM and molasses levels in Fusicaulis silage on the apparent digestibility of DM and CP as well as metabolizable energy (ME) content occurred. The inclusion of molasses resulted in a reduction in the ADF (P=0.08) and NDF (P=0.05) digestibilities. Apparent EE digestibility was reduced (P<0.05) by a higher DM level. DM content of cladode silage had no influence (P=0.42) on DMI by sheep. The inclusion of molasses influenced DMI favourably (P=0.54). In contrast with molasses, a higher DM level (37.4%) in silage resulted in a higher (P<0.05) metabolizable energy intake (MEI). Cladode silage supplied more or less in the ME requirements of 30 kg wether lambs. Weight losses were decreased (P=0.07) by the inclusion of 24% molasses. It was concluded that the laxative effect of cladode silage resulted in a higher rate of passage through the digestive tract. Accordingly the digestibility and ME content of cladode silage is relatively low. Accompanied by a low DMI, cladode silage as a sole energy source supplied only in the maintenance requirement of sheep, especially when molasses was included at ensiling.

Afrikaans: ’n Laboratoriumstudie is uitgevoer om die voedingswaarde van verskillende Opuntia variëteite vanaf chemiese ontledings te ondersoek. Eenjaar-oud turksvyblare vanaf ses verskillende variëteite van Opuntia ficus-indica naamlik Castello, Chicco, Fucicaulis, Montery, Maroda en Rubasta is ewekansig in vyf replikasies geoes. Die hoogste (P<0.05) gemiddelde droëmateriaalinhoud (DM) is vir die Chicco variëteit waargeneem en was die gemiddeld vir al die variëteite oor die algemeen laag (9.13%). Geen betekenisvolle (P<0.05) verskille in asinhoud het voorgekom nie. Betekenisvolle (P<0.05) verskille tussen variëteite is vir ruproteïen (RP) (3.7 tot 8.1%), suurbestande vessel (SBV) (13.6 tot 17.4%), neutraalbestande vessel (NBV) (19.9 tot 38.5%), sellulose(2.4 tot 14.8%), hemisellulose (4.5 tot 12.7%), lignien (2.5 tot 21.5%), nie-veselkoolhidrate (33.4 tot 48.6%), eterekstrak (EE) (1.9 tot 2.4%) waargeneem. Die gemiddelde mineraalsamestelling was as volg: fosfaat (P) 0.18%, kalium (K) 3.02%, kalsium (Ca) 2.3%, magnesium (Mg) 3.6% en natrium (Na) 0.04%. Daar is tot die slotsom gekom dat turksvyblare in die algemeen as ’n hoë energiebron met ’n energiepeil tussen die van ’n ruvoer en kragvoer, met ’n lae ruproteïen en hoë Mg, K en Ca- inhoud geklassifiseer kan word. In ’n tweede studie is die invloed van DM-(7.12 tot 27.6%) en melasse-inhoud (0-24%) op die fermentasie-eienskappe van Fusicaulis turksvyblaarkuilvoer ondersoek. Eenjaar-oud turksvyblare is in drie liter vierkantige plastiese bottels (ses replikasies) ingekuil. ’n Hoër DM- inhoud is gekenmerk met ’n laer (P<0.05) SBV-, NBV-, RP- en EE- inhoud. Die insluiting van melasse het ’n laer (P<0.05) SBV-, NBV- en EE- inhoud tot gevolg gehad. ’n Hoër (P<0.05) asynsuurinhoud (AA) in Fusicaulis kuilvoer is waargeneem soos die DM en melassepeile toegeneem het. ’n Hoër kuilvoer DM- inhoud het met ’n hoer (P<0.05) propioonsuur (PA) en bottersuurinhoud gepaardgegaan. Geen betekenisvolle (P<0.05) invloed van melasse op PA en BA het voorgekom nie. Melksuur en pH van turksvyblaarkuilvoer het met hoër DM- en melassepeile toegeneem. Daar is tot die slotsom gekom dat die hoë vog, AA-, PA- en BA- inhoud van turksvyblaarkuilvoer, inname en diereprestasies nadelig kan beïnvloed. In ’n derde studie is die effekte van DM- (35.5 en 37.4%) en melasse- (0 en 24%) inhoud van eenjarige ingekuilde turksvyblare op die droëmateriaalinname (DMI) en skynbare verteerbaarheid deur skape ondersoek. Vier en twintig Merinohamels is ewekansig in 4 groepe van 6 elk ingedeel. Geen statisties betekenisvolle (P>0.05) invloed van DM- en melassepeile in Fusicaulis kuilvoer op die skynbare verteerbaarheid van DM en RP asook metaboliseerbare energie- (ME) inhoud het voorgekom nie. Die insluiting van melasse het SBV- (P=0.08) en NBV- (P=0.005) verteerbaarheid verlaag. Skynbare EE- verteerbaarheid is deur ’n hoë DM- inhoud verlaag (P<0.05). DM- inhoud van turksvyblaarkuilvoer het nie DMI van skape beïnvloed (P=0.42) nie. Die insluiting van melasse het DMI positief beïnvloed (P=0.054). In teenstelling met melasse, het ’n hoër DM- peil (37.4%) in kuilvoer met ’n hoër (P<0.05) ME- inname gepaardgegaan. Turksvyblaarkuilvoer het min of meer in die ME- onderhoudsbehoeftes van 30kg Merinohamels voorsien. Gewigsverliese is verminder (P=0.07) deur die insluiting van 24% melasse. Daar is tot die slotsom gekom dat die lakseereienskappe van turksvyblaarkuilvoer die spoed van deurgang deur die spysverteringskanaal verhoog. Gevolglik is die verteerbaarheid en ME- inhoud van turksvykuilvoer relatief laag. Gepaard met ’n lae DMI, voorsien turksvyblaarkuilvoer as enigste energiebron slegs in die onderhoudsbehoeftes van skape, veral waar melasse met inkuiling ingesluit is.