|Abstract or Summary
- A series of eight trials was conducted to determine if supplementation
with arginine improved growth of young rats, Japanese quail
and swine fed low-lysine diets. In five rat trials, with a variety of
basal diets, no evidence of a "sparing effect" of arginine on the lysine
requirement was found. A significant (P < 0. 001) depression in
growth was observed in one of the rat trials when the animals were
fed added arginine.
Two trials with Japanese quail and one with swine were conducted
to examine this interrelationship. There was no response to added
arginine in either of these species.
Based on the results of these eight experiments it was concluded
that arginine supplementation is of no value in reducing the adverse
effects on growth of low lysine diets fed to these monogastric species. In the second part of this study eight trials were conducted with
swine and rats to examine some implications of feeding dried whey to
monogastrics. Since dried whey is high in lactose, some nutritional
aspects of lactose utilization were also studied.
Because lactose is digested by bacterial action in the large
intestine of the post-weaning animal, it was postulated that through
stimulation of bacterial growth, fiber digestion might be enhanced in
monogastrics fed lactose-containing rations. Inclusion of 10% whey in
a swine grower ration containing 20% alfalfa did not influence growth
rate. In a digestibility study with rats, substitution of 25% lactose in
the diet reduced fiber digestibility.
In feeding trials with swine, levels of 2 to 10% added whey were
found to increase average daily gains and feed efficiency.
Starter rations containing dried whey were compared to the
currently used Oregon State University starter ration containing dried
buttermilk. Results of this trial indicate that dried whey can be used
to replace the more expensive dried buttermilk.
Reducing sugars such as lactose may form indigestible complexes
with certain amino acids, particularly lysine, by what is
referred to as the Maillard or Browning reaction. This reaction is
stimulated by heat. Since the pelleting process involves considerable
heat, it is conceivable that through the Maillard reaction some of the
lysine in pelleted rations containing whey could be unavailable. Three rat experiments were conducted to examine some factors influencing
the Mail lard reaction, The substitution of 5 or 10% lactose for starch
resulted in a significant (P < 0.01) depression in growth, which was
largely overcome by supplementation with 0.3% lysine.
The effects of various carbohydrate sources were compared. It
was found that the substitution of lactose, dried whey and molasses
for starch at the 5 or 10% level all produced a significant decrease in
gains. The addition of amino groups in the form of glutarnic acid or
urea failed to overcome the depression in growth caused by 5% lactose,
but (NH₄)₂SO₄ did increase gains,
The effects of several feed additives and fat sources on the
Maillard reaction were also studied. In a 10% lactose diet vegetable
oil increased gains when substituted for lard and alfalfa meal decreased
gains. Neither copper sulphate, zinc sulphate nor calcium carbonate
had any affect on the growth depression caused by 10% lactose.
It was concluded that dried whey should be utilized in a supplementary
capacity in swine feeds, but further work should be conducted
on such factors as the effects of feed processing and interrelationships
with other ration ingredients.