Under free grazing providing no other sources of nutrients, the grazing strategy must aim towards finding the best pasture in each season without excessive travel and with a stocking rate, that is compatible with good renewal of the vegetation and the best sustainability of forages and browse. The presence of a goatherder will assure this and improve productivity over un-supervised grazing. Nevertheless the nutrient composition varies tremendously from season to season and despite the selectivity of grazing goats, the daily supply often falls short of nutrient requirements of production and at times even of maintenance, so that the goats actually lose milk production, weight and potentially health (Table 3) (Ramirez et al., 1991; Papachristou and Nastis, 1996).
Limited grazing will be a normal consequence by goats when fed supplementary grain. The strategy could be based on the amount of daily milk produced at the rate of 2.5 lb milk per l lb grain or more depending on the price of grain to the price of milk ratio. An example calculation would be, if the milk price is $12/100 lb, the grain price $200/t and the cost of feeding is 50 percent of total milk production costs:
2.5 lb milk @ $0.30 (12.-/100x2.5)
= $0.10 grain cost (200.-/2000)X 2,
= $0.30 - 0.20,
leaving $0.10 for other production expenses and profit.
A superior feeding strategy would be based on body condition scoring (Table 8). Low scoring goats (1 - 2.5) receive grain supplementation at < 2.5 lb grain :1 lb milk ratio, while the higher scoring goats (3.0 - 5.0) are fed at a feed:milk ratio of 3:1. This will correct production loss due to undernutrition and it will prevent problems of fat goats (Santucci et al., 1991). Body condition scoring has been successfully developed for dairy cattle, but applies equally well to dairy goats even in the absence of published suitable picture guides. Body condition score is the visible end result of appropriate or insufficient feeding in relation to production. Out-of-target-range scoring goats will produce less milk and a lower meat price. Reproductive efficiency is significantly reduced by out-of-target-range body condition scores. Also disease frequency is increased.
Confinement feeding abrogates any nutrient supply from pasture, although for better health of udder, feet, vitamin D supply from the sun and control of internal parasites some outdoor yards should be provided. The entire nutrient supply must be calculated from composition and requirement tables. Software programs for dairy and beef cattle are available, which have some scaled-down provision on bodyweight. More appropriate would be goat specific programs based on the current NRC (1981) and up-dated tables. The University of Wisconsin developed a program, which has not seen widespread use, partly because in the USA no silage is fed to goats as it is the major feed for cows on many farms.
The concept of free choice feeding without rationing to individual goats has been tried successfully (Haenlein, 1978). Over a 2-year period 5 Saanen, weighing 133 - 205 lb, produced in 2 lactations from 2,033 - 4,554 lb milk with 3.0 - 3.3 percent fat. Their free choice intake of mixed hay per year ranged from 393 - 459 lb, their grain ration 1,688 - 1,692 lb per year, besides green chop grass, fodder beets and dry beet pulp. The composition of the grain ration was 21 percent crude protein and 10 percent crude fiber. Daily intake between high and low milkers varied from 1 to 8 lb grain; highest daily milk production was 17.8 lb. Production cost analysis in the 2nd year between the highest producer with 4,554 lb milk showed $293.50 for total feed costs vs. $272.19 for the lowest producer with 3,321 lb milk, or $6.44/100 lb milk for the high producer vs. $8.20/100 lb milk for the low producer.
Total mixed ration (TMR) is another approach to free choice feeding, which is very popular in dairy cattle feeding, except that with dairy cattle the major component is silage, mostly corn silage, which is generally not used nor available for goats. Grass silage is fed in Norway routinely and successfully to dairy goats. For many years I have used for my Saanen goats a total mixed ration free choice successfully, and they milked heavy--above 10 lb per day-- even bred out-of-season, kidded twice the year, never had any over-eating disease nor were they vaccinated against enterotoxemia, and had no internal parasite problems despite my not worming them.