Vitis vinifera

Grape, wine grape

Useful reference: 318

A strong vine of medium height, but often trained to a short stout trunk. The oval or round berries grow in clusters. The juice of the berries is fermented into wine. After the juice has been pressed out of the berries, the residue - grape pomace or winery pomace - is about 10% by weight of the total grape input. If the grapes are stripped from the stalks before processing, the residue consists of about 40% seeds and 60% skin and pulp. Winery waste pressed with the stalks is composed of about 30% stalks, 30% seeds and 40% skin and pulp. Winery pomace can be stored for a time by heaping and pressing, but dust formation may become a problem owing to disintegration of the pulp. It is easy to make silage of winery pomace as the initial acidity is already high. The pomace may also be separated into skin and seeds by loosening the pulp from the seeds in a breaker, after which a vibrating sieve separates the seed from the skin. Both fractions are then dried; the marc (skin and pulp) is ground in a mill and bagged; and the dried seeds are removed from the dust and stored in silos. The seeds contain 8-22%n edible oil and can be either pressed or extracted with solvents.

USES. The seed oilcake has no feed value as it is not only too fibrous but also contains tannic acid; however, it has been used as a carrier for molasses in cattle feed. Winery pomace including stalks has little value in animal feeding. Its chemical composition is similar to other types of winery pomace, but the digestibility of fibre is much lower and its nutritive value is comparable to that of straw. Winery pomace from stalked grapes has been fed to dairy cows in amounts up to 6.5 kg a day. When supplemented with concentrates and legume hay, it proved to be a good feed. At this level of inclusion the milk yield tends to drop and the butterfat content increases. Larger amounts cause inflammation of the mucosa in the digestive system. Grape marc has a lower fibre content than pomace and has been used for horses in proportions of up to 10% of the ration. The digestibility can be increased by soaking the marc in hot (90 C) water for about twenty minutes to remove the tartrates.

					As % of dry matter
				DM	CP	CF	Ash	EE	NFE	Ca	P	Ref
Fresh leaves,
Pakistan				30.0	15.8	9.2	8.6	13.4	53.0	2.25	0.16	308
Winery pomace
(stalk, skin,
seed), Italy				40.6	11.7	25.5	7.7	9.9	45.2			318
Winery pomace
(skin, seed),
Italy				46.5	13.7	23.6	12.8	7.0	42.9	0.82	0.20	"
Winery pomace
(stalk, skin),
Germany				88.8	14.9	35.8	8.9	5.0	35.4			78
Winery pomace
(skin), Italy					14.4	22.3	6.3	8.3	48.7	0.79	0.27	318
Winery pomace
(skin), Chile				88.9	18.3	32.0	8.0	6.4	35.3	1.63	0.33	315
Seeds, Chile				93.0	9.6	45.7	4.2	15.2	25.3	0.62	0.22	"
Oilcake (hydr-
aulic press)				88.5	13.6	44.0	5.2	8.5	28.7			512
							Digestibility (%)
					Animal		CP	CF	EE	NFE	ME	Ref
Stalk, skin, seed					Sheep		18.4	8.5	77.8	40.9	1.44	318
Skin and seed					Sheep		9.2	34.5	45.3	41.0	1.23	"
Stalk and skin					Cattle		14.0	27.0	55.0	36.0	1.11	78
Skin					Sheep		5.5	5.0	58.9	42.2	1.20	318
					Nylon bag degradability
						a	b	c		12hr	48hr	Ref
						(%)	(%)	(/hour)		(%)	(%)
Grape pulp, France					DM	11.5	46.0	0.0191			41.2	627
Dehydrated grape marc					N	15.7	11.6	0.0573		21.5	26.6	629
	[P (rumen degradability at time t) = a+b*(1-exp(-c*t))]