Verteerbaarheid van katoensaadbevattende diete en die effek van lanolienbyvoeging daarop by skape

Abstract

Digestibility or diets containing cottonseed and the effect or supplementary lanolin thereon in sheep. The apparent digestibility of nutrients in four diets (A, B, C and D) containing 0, 10, 15 and 20% whole cottonseed respectively, was determined in sheep at a feeding level of 45 g DM/WO,7S /d. The apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), crude fibre (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), nitrogen free extract (NFE) and gross energy (GE) all decreased significantly (P < 0,05) or highly significantly (P < 0,01) in the cottonseed diets. This was apparently due to depressed fibre  digestibility. The digestibility of the ether extract (EE) fraction, however, increased significantly (P < 0,05) and highly significantly (P < 0,01) in the  cottonseedcontaining diets. This was probably due to the high digestibility of cottonseed oil. Nitrogen retention also increased highly significantly (P < 0,01) with increases in the whole-cottonseed content, probably due to more efficient bacterial protein synthesis (BPS). In an attempt to alleviate the negative effects of  cottonseed oil on rumen metabolism, lanolin was supplemented as an emulsifier to five diets (0%, 1%, 2%,4% and 8% lanolin to diets 1,2, 3, 4 and 5, respectively). The diets contained 23 - 25% whole cottonseed. The apparent digestibility of nutrients was determined by feeding the diets to five groups of wethers (four per group) at 45 g OM /WO,7S / d. Because of the promising results obtained with the 2% lanolin inclusion, the work was repeated with Rations 1 and 3 (with 0 and 2% lanolin respectively) using 10 wethers per group. The apparent digestibilities of the NDF (ONDF) and the nitrogen (DN) were significantly (P < 0,05) and highly significantly (P < 0,01) higher for Ration 3 (2% lanolin) than for Ration 1 (0% lanolin). The small increase in the total digestibility of nutrients with the inclusion of 2% lanolin, seems too small to justify its inclusion in diets containing high percentages of whole cottonseed.

Die skynbare verteerbaarheid van voedingstowwe in vier diete (A, B, C en D) wat onderskeidelik 0, 10, 15 en 20% heel katoensaad bevat het, is by skape op 'n voedingspeil van 45 g DM/WO,7S /d bepaal. Die skynbare verteerbaarheid van droe materie (DM), organiese materie (OM), totale ruproteien (TRP), ruvesel (RV),  neutraalbestande vesel (NBV), suurbestande vesel (SBV), stikstofvrye ekstrak (NVE) en bruto energie (BE) is progressiefbetekenisvol (P < 0,05) en hoogs betekenisvol (P < 0,01) verlaag met die insluiting van groter hoeveelhede heel katoensaad. Dit is waarskynlik te wyte aan die verlaging in ruveselverteerbaarheid. Die verteerbaarheid van die eterekstrakfraksie (EE) is egter betekenisvol (P < 0,05) en hoogs betekenisvol (P < 0,01) verhoog deur die insluiting van katoensaad. Dit is waarskynlik toe te skryf aan die hoe  verteerbaarheid van katoensaadolie.  Stikstofretensie is ook hoogs betekenisvol (P < 0,01) verhoog deur die insluiting van katoensaad wat waarskynlik aan doeltreffender bakterie-proteiensintese (BPS) toegeskryf kan word. In 'n poging om die negatiewe effekte van katoenolie op rumenmetabolisme op te hef, is lanolien as emulsifiseerder by vyf diete (0%, 1%,2%,4% en 8% lanolien by diete 1, 2, 3,4 en 5 onderskeidelik) gevoeg. Die diete het 23-25% heel katoensaad bevat. Die skynbare verteerbaarheid van die voedingstowwe is bepaal deur die diete teen 45 g DM/WO,7S /d aan vyf groepe van vier hamels elk te voer. Na aanleiding van die gunstige resultate wat met die 2% lanolienbehandeling verkry is, is die werk met Rantsoene 1 en 3 (0 en 2% lanolien) met 10 hamels per groep herhaal. Die skynbare verteerbaarheid van die NBV (VNBV) en van die stikstof (VN) was betekenisvol (P < 0,05) en hoogs betekenisvol (P < 0,01) hoer vir Rantsoen 3 (2% lanolien) as vir Rantsoen 1 (0% lanolien). Die klein verbetering wat in die to tale verteerbaarheid van die voedingstowwe verkry is met die insluiting van 2% lanolien, is te gering om van praktiese waarde te wees.