Appendix 4 Effects of feeding systems and dietary manipulations on demand for feeds

Table 1 Alternative ration formulations of pig diets with different quality protein sources

	Composition of diets (g/kg DM)
Ingredient	Cereals/soyabean meal diet	Cereal by-products/ rapeseed meal diet
Barley	113	102
Wheat	503	203
Soyabean meal 48	274	189
Tallow	18	38
Wheatfeed	50	51
Maize gluten	-	261
Rapeseed meal	-	122
Minerals/vitamins	42	34

Digestible energy (MJ/kg)	13.5	13.5
Total lysine content (%)	1.1	1.1
Crude protein (%)	20.5	22.0
Total N consumption (kg/pig) (1)	9.8	10.6

1. Assuming pig growth of 70 kg liveweight in 100 days @ 3.0 FCE in both diets

Table 2 The effect of multi-phase feeding on nitrogen economy of growing and breeding pigs

	Feed utilization and nitrogen balance under different feeding systems
Feed parameters	Traditional feeding system	Multi-phase feeding system
Growing pigs (25-105 kg) (growth rate 0.68kg/day)
No. of feeding phases	2	3
Feed consumption/phase	43kg @17% protein	35kg @ 17% protein
	203kg @ 15% protein	65kg @ 15% protein
		146kg @ 14% protein
Total feed consumption	246 kg	246 kg
Protein consumption	37.8 kg	36.1 kg
N excretion	4.18 kg	3.92 kg
Breeding sow (2.25 litters/year, 25 day lactation feeding period)
No. of feeding phases	1 (same feed continuously)	2 (15% protein when lactating, 12% protein when dry)
Feed consumption/phase	1300 kg @ 15% protein	252kg @ 15% protein
		1048kg @ 12% protein
Total feed consumption	1300 kg/year	1300 kg/year
Protein consumption	195 kg/year	163.6 kg/year
Reduced N excretion (1)		5.0 kg/sow/year

Source: after Lenis (1985)

Table 3 Feed requirements and feeding periods for beef cattle under different roughage and concentrate feeding regimes (1)

Feeding system	Growth rate	Feeding period	Total feeds consumed (2) (kg FW)
(concentrate as % total feed)	(kg/day)	(days)	Roughage	Concentrate
13%	0.12	1667	8835	1334
25%	0.35	571	2741	914
42%	0.68	294	1176	853
61%	1.06	189	567	888

1. Assuming: steers of medium sized breed over 200-400kg liveweight

roughage equivalent to hay (ME 7.5 MJ/kg, CP 80g/kg DM)
concentrate nutritive value ME 12.9 MJ/kg, CP 155g/kg DM

(diets calculated to account for supplementation and substitution of roughage by concentrate)

2. Feeds consumed over whole feeding period, in fresh weights (hay and concentrates at 83% DM)

Table 4 Effects of increased milk yield on feed requirements and feed efficiency

	Feed consumption and efficiency at different yield levels (1)
Milk yield	Forage use	Concentrate use	Crude protein use	Feed efficiency
	(kg DM/	(kg DM/	(kg/	Total feed	Concentrates	CP
(l/cow/year)	cow/year)	cow/year)	cow/year)	(kg/l milk)	(kg/l milk)	(g/l milk)
5000	3300	1200	678	0.90	0.24	136
6000	3120	1560	717	0.78	0.26	120
7000	2885	2030	769	0.70	0.29	110
8000	2620	2560	828	0.65	0.32	104
9000	2280	3240	902	0.61	0.36	100

Source: based on milk yield and feed data from UK dairy farms, Genus (1994)

1. Assuming: feed concentrate @ 18% crude protein, basal forage diet @ 14% crude protein, 1 kg additional concentrate substitutes 0.5 kg basal diet; feed requirements 60 MJ ME/day for maintenance and 5 MJ ME/litre of milk.