A TEST OF THE USEFULNESS OF A COMMERCIALLY AVAILABLE MILL « WASTE PRODUCT » ( AB-84 ) AS FEED FOR STARVING REINDEER

3 Norwegian reindeer were first fed lichen ad libitum for 40 days, then they were starved for 3 days, and thereafter offered a commercially available mill «waste p r o d u c t » (AB-84) ad libitum. O n e animal refused to eat A B 8 4 and was excluded. When eating lichen average daily dry matter intake was 1.1 ± 0.4 kg, while when eating A B 8 4 after the starvation period it averaged 1.1 kg at day 1, increasing to 2.5 kg at day 7. After 12 days daily dry matter intake varied between 2 and 4 kg. The rumen dry matter percentage was 16 when eating lichen, 6 after 2 days of starvation, and 17 after eating A B 8 4 for 5 days. Ruminal p H was 6.4 ± 0.3 when eating lichen, increasing to 7.4 after 3 days of starvation and dropping to an all time low of 6.1, 12 hours after refeeding. The viable bacterial count was 4.7 x 1010 ± 2.7, 5.5 x 108 ± 2.0 and 3.1 x 10'° ± 1.7/ml rumen fluid when the animals were eating lichen, had starved for 3 days and had been eating A B 8 4 for 5 days, respectively. The rumen ciliate protozoa numbered 17.1 x 105 ± 2.7/ml rumen fluid, when eating lichen, dropping to 4.3 x 105 ± 0.6./ml after 3 days of starvation. A further drop to 1.8 x 10s ± 0.5/ml was observed 1 day after refeeding, but the rumen ciliate number was normalized at 15 x 105 ± 1/ml already 8 days after refeeding. These results indicate that the mill «waste product» (AB-84) is very well tolerated even by reindeer suffering from starvation. Since it is moreover commercially available at a favourable price it could be of interest to reindeer herders. In any case, it deserves to be tested under controlled conditions on a larger number of animals.


INTRODUCTION
In Scandinavia reindeer are often prohibited from access to food when snow and ice cover the range.It follows that the animals will suffer from starvation under such circumstances.The natural winter diet of reindeer primarily consists of lichen, and some reindeer herders are known to use lichen, harvested in the fall, as a feed supplement for reindeer during winter.Lichen has, however, high water content and is difficult to keep, unless it is frozen, and it is costly to obtain in adequate amounts.In attempts to satisfy the frequent demands for a commercially available feed which "can be offered ad libitum to starving reindeer different concentrates have been tested.More often than not, however, starving reindeer suffer from digestive disturbances, or even die, when offered concentrates, unless they are gradually adapted to the feed.This is at least in part due to the fact that most concentrates have a high content of easily soluble protein and carbohydrates.In reindeer not adapted to such a diet this produces an abrupt increase in ruminal fermentation rate which results in a lowering of rumen pH.This in turn favours the growth of lactate producing bacteria further depressing rumen pH.Ruminal acidocis depresses other microbes necessary for adequate digestion of this diet and also inhibits the motoric activity of the entire alimentary system.This results in the passage of undigested protein and carbohydrates from the rumen into the small intestine -ultimately leading to enteritis and death.It follows that starved reindeer should be offered a diet high in fibre and low in soluble protein and carbohydrates to avoid an uncontrolled increase in rumen fermentation rate.A commercially available mill «waste product* (Table 1) seems to satisfy these demands.Moreover, in a pilot experiment we did not detect any appreciable ruminal acidosis or signs of indigestion when an animal fed only lichen for one mondi was offered this feed ad libitum after four days of complete starvation.Encouraged by this result we have presently investigated its effects on ruminal pH and microbial activity in starved reindeer in more detail.

MATERIAL AND METHODS
Two 4-5 years old females and one 2 years old male Norwegian reindeer (Rangifer tarandus tarandus) obtained from a local herd outside Tromsø in early winter were used in this study.All three animals were surgically equipped with permanent rumen fistula (Hecker 1974).The two females had no previous experience with artificial feed while the male had.The latter was therefore innoculated with rumen fluid from the other two.All animals were kept in private outdoor pens and offered lichen and snow only for a period of 40 days after the fistulation, and then starved completely for 3 days.After this ordeal they were offered a fine-grained and pelleted (0 = 9 mm) mill «waste product» (AB-84) ad libitum.Feeding always took place at 0900 h.The composition of this feed is given in (Table I).It should be noted that mill «waste products* may differ in its composition, and that the results of this report only relate to the composition given in Table I.The main components of the feed are waste from the grain mills: small bits of straw from oats and barley, weeds, seeds of weeds, shaffs from oats and barley.Potato starch was used as a binding agent in the pelleting process.The feed is commercially available at about half the cost of RF-71 (Jacobsen and Skjenneberg 1976), but feed intake is normally greater when the animals are offered AB-84 ad lib.Thus, maintenance cost could run at about the same level.The food intake of each animal was measured daily and dry matter intake determined.Body weight was recorded at weekly intervals until the start of the starvation period, whereafter it was recorded every day.
Ruminal pH was measured at 0900, 1200, 1500 and/or 2000 h.using a Radiometer® GK 230 IC Electrode connectcu to a Radiometer® pH meter model 26.The electrode was introduced through the fistula and immersed in the rumen content for at least 3 min before any reading was recorded.200 ml of rumen content was collected anaerobically through the fistula by use of a rumen pipette, at intervals, always at 0900 h.50 ml of the rumen content was dried for determination of its dry matter percentage.The rest of the samples was strained through iwo layers of muslin, and the rumen fluid thereby obtained was used for determination of ruminal ciliate and viable bacterial numbers.
For the estimation of the total number of rumen ciliates 10 ml of rumen fluid was fixed in 3% glutaraldehyde.The samples were diluted in a phosphate buffer and the number of ciliates determined in 50 U. 1 pools on a plancton counting chamber under a light microscope (Imai and Otimoto, 1981, G. S. Coleman Pers. Comm.).
The number of viable bacteria pr.ml rumen fluid was determined after dilution and cultivation for 48 h in Hungate anaerobic tubes containing a general nonselective carbohydrate medium as substrate.The medium was prereduced by cystein, and rezauserin was used as an anaerobic indicator (Orpin, 1982).

RESULTS
One of the animals, a very nervous female, refused to eat the mill «waste products (AB-84) when it was offered after the starvation period, and was therefore excluded.Figure 1 shows the dry matter intake of the remaining animals.Average dry matter intake was 1.1 kg ± 0.4 kg/day when the animals were eating lichen ad lib..When they were offered AB-84 after 3 days of starvation average dry matter intake was 1.1 kg at day 1, increasing almost linearly to 2.5 at day 7, whereafter dry matter intake stabilized in both animals at 4 and 2 kg/day, respectively.
The dry matter percentage of the rumen content was 16 when the animals were eating lichen, 6 after 2 days of starvation and again 17 after eating AB-84 ad lib.for 5 days.
Figure 2 shows the body weight development of the same period.Both animals lost weight when eating lichen, but rapidly gained weight when offered AB-84 ad lib.after the starvation period.
Figure 3 shows ruminal pH, which was 6.4 ± 0.3 when the animals were eating lichen, increasing to 7.4 after 3 days of starvation and dropping to an all-time low of 6.1 twelve hours after refeeding with AB-84 ad lib..
Figure 4 shows the changes in the number of viable bacteria in response to starvation and refeeding.
The number was 4.7 x 10 10 ± 2.7/ml when eating lichen, dropping to 6.5 x 10' ± 4.0/ml and 5.5 x 10 s ± 2.0/ml after 2.5 and 3 days of starvation, respectively.After eating AB-84 ad lib.for 8 days, however, the number was back at 4.3 x 10 10 ± 1.6/ml.2.7/ml were found.After 3 days of starvation the number had dropped to 4.3 x 10 5 ± 0.6/ml.This represents a loss of 75% of the total rumen ciliate population.The number of rumen ciliates continued to drop (to 1.8 x 10 5 ± 0.5/ml) the first day after refeeding with AB-84, but was back at 1.5 x 10 6 ± 1.0/ml already after 8 days of eating AB-84 ad libitum.

DISCUSSION
This study indicates that our mill «waste product* AB-84 is tolerated very well, even when offered ad libitum to reindeer suffering from starvation.Thus, we did not detect signs of severe ruminal acidosis (Fig. 3) and there was a very rapid recovery of both bacteria (Fig. 4) and ciliate protozoa (Fig. 5) upon refeeding with AB-84 after the starvation period.The relatively high fibre content of AB-84 probably stimulates rumination and thereby salivation more than most «highyield» concentrates.Haufman et al. (1979) suggest, that at least 20% crude fibre is required in the diet to give adequate
In this respect the large diameter of the pellets used in this study probably also put a restraint on the ruminal fermentation and thereby avoiding an uncontrolled reduction of pH.
Haufman et al. (1979) has, moreover, reported that the ciliate protozoa may excert a similar effect on ruminal fermentation by their significant uptake of starch.The fact that our AB-84 feed supports the growth of ciliate protozoa instead of destroying them as most concentrates do after abrupt changes in the diet (Dirksen 1970) is in support of the view that the ciliates contribute to the «buffering» of the rumen during excessive intake of carbohydrates.
The drop in the number of rumen ciliate protozoa the first day after refeeding with AB-84 is probably due to a temporary increase in the outflow from the rumen following a very low rumen water turnover rate during starvation (Mathiesen, unpublished).
Unlike Bøe and Jacobsen (1981) and Bøe et al. (1982) using the reindeer feed, RF-71, we did not detect any signs of irregular appetite or symptoms of indigestion in our animals when using AB-84.This finding is supported by the fact that the dry matter percentage of the rumen content of our animals was similar after eating AB-84 for five days as compared with when they were eating lichen.
The high content of vitamin-B in grain products, known to stimulate appetite in ruminants, could have contributed to the steadily increasing intake of AB-84 after the starvation period in our animals (Fig. 1).The exceedingly rapid increase in body weight during the first few days of refeeding with AB-84, is at least in part caused by a much increased rumen water volume, as compared to when the animals were eating lichen (Mathiesen, unpublished).RANGIFER, 4 (1), 1984 Det er viktig å vaere oppmerksom på at sammensetningen av kornavrens kan variere og at resultatene som presenteres ber forutsetter en sammensetning som angitt for AB-84.Matre (1981) has reported symptoms of mechanical destruction of the intestinal tract when using a mill «waste product* for prolonged periods in cattle.This potential problem has not been investigated in any detail using AB-84 in reindeer, but we have kept reindeer on AB-84 only, for a period of seven months, without apparent ill effects.In any case, there is no need, or reason, for the use of AB-84, or any other concentrate for that matter, for prolonged periods; only in times of nutritional crisis.
In such circumstances it is, of course, imperative that the animals eat what they are offered.Reindeer are notorious for being very selective in what they eat and suspicious of new food-items.Accordingly, one of our animals, a very nervous female, refused to eat our AB-84 feed.Such incidents of poor cooperation could possibly be avoided if the animals of the herd were accustomed to this feed during marking and slaughtering round-ups during summer and autumn.
In conclusion, this study indicates that our mill «waste product* AB-84 is very well tolerated by reindeer, even after periods of acute starvation.It is moreover commercially available at a favourable prize, and could be of interest to reindeer herders.
In any case, it should be in the interest of our reindeer management authorities to test it under controlled conditions on a larger scale than we have had the means to do.

Fig. 1 .
Fig. 1.Dry matter intake in one male (O) and one female (•) Norwegian reindeer offered first lichen ad lib., and then after a 3-day starvation period, a mill «waste product" (AB-84) ad lib..

Figure 5 RANGIFER
Figure5shows the changes in the number of rumen ciliates in response to starvation and refeeding.When the animals were eating lichen 1.7 x 10 6 ±

Fig
Fig. 5.The number of rumen ciliate protozoa/ml rumen fluid in two different Norwegian reindeer (mean ± standard deviation).A -when eating lichen ad lib.; B -after 3 days of complete starvation; Cafter eating (AB-84) ad lib.for 1 day; D -for 2 days; E -for 5 days; and F -for 8 days.