T H E AMERICAN SOCIETY OF ANIMAL P R O D U C T I O N
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THE RELATION OF THE LIGNIN A N D CELLULOSE CONTENT OF PASTURE HERBAGE TO ITS NUTRITIVE V A L U E
E. W. CRAMPTON
Macdonald ColZege, Quebec, Canada
(Abstract. Complete article to be published in the Journal of Nutrition.)
Recent feeding trials with rabbits have directed attention to the
fact, amply demonstrated in published data but frequently ignored
in the interpretation of pasture studies, that the commonly used
feeding stuffs analysis, with or without supplementary data for
such mineral elements as calcium and phosphorus, is often quite
inadequate as an index of probable nutritive value. Data are presented to show that there may be no consistent relation between
any constituent of such an anlysis and the live weight gains made
by rabbits fed diets consisting of clipped, dried, pasture herbage.
It is postulated that lignificafion is an important cause of the
often observed decrease in feeding value of pasture herbage during seasons or parts of seasons when climatic conditions are unfavorable to rapid vegetative growth; and that the failure of the
usual feeding stuffs analysis consistently to predict the feeding
value of such forage is traceable, in part, to the fact that it does
not partition the fat-nitrogen-ash-free fraction according to its
chief biologically significant groups, vis.: (1) starches and sugars,
(2) hemicellulose, (3) cellulose, and (4) lignin.
Based on an experimental study of methods applicable for use
with animal feeds and the feces produced therefrom, procedures
for the chemical determination of lignin and cellulose are proposed. Results of feeding trials are presented in support of the
suggestion that in lieu of crude fibre and nitrogen-free extract,
this fraction of pasture herbage may, with more nutritional significance, be partitioned into lignin, cellulose, and other carbohydrate--the last being determined by difference i n a manner
analogous to that used for nitrogen-free extract.
REPORT
ON THE FOURTH I N T E R N A T I O N A L
L A N D S CONGRESS OF 1937
GRASS-
R. H. LUSH
Louisiana Agricultural Experiment Station
It was my privilege to attend the sessions of the Grassland Congress at Aberystwyth, Wales, on July 15 to 17, and to make tours
in England and Scotland both before and after the Congress. About
400 delegates, representing 37 countries of widely varying climatic
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conditions, were present. Sixty-five papers were presented on
management and fertilization, nutritive value of pastures, fodder
conservation, seed production, and plant breeding, as well as related subjects. Abstracts of these papers are already available,
and it is my intention to make only a few observations on the
whole tour.
One is impressed with the great amount of work on selection
and breeding of pasture grasses and legumes. Especially is this
true in Wales, where great emphasis is now placed on adaptability
and survival of various plants under grazing conditions. Much
work has been done to develop a leafy, low-growing strain of timothy, for example, that is able to maintain itself in pastures and
yet can be harvested for seed. The breeding of white clover at
Aberystwyth is classic. Among the many strains developed are
some that are more prolific and more resistant than the original
wild white clover. Much progress in the search for real pasture
plants to replace hay plants in pasture mixtures was reported from
other countries represented.
The interest in pasture management, however, was surprising
and most gratifying to the animal husbandman. Reports and discussions emphasized the regulation of grazing to give maximum
returns and to promote longevity of desirable pasture vegetation.
Grazing cattle and sheep together is a common practice in England, and experimental results in weed control and gains per acre
justify the practice. Close grazing encourages the growth of white
clover, but persistent close grazing destroys the grasses. A balance between the various factors that make for productive pasture is necessary to successful pasture management. Professor
R. G. Stapledon of Aberystwyth, president of the Congress, listed
in an informal talk the following steps in pasture management:
(1) use the mowing machine and firestick; (2) use 1,000 pounds
or more of basic slag per acre; (3) sow white clover; and (4) keep
down weeds and waste, or on moist lands, scratch the land, sow
seed and add phosphate. When it is possible, plow the land and
let it lie for 12 months before pasturing. Management oS livestock
on the land is more important to pasture production than climate
and soil. The most important operation on English pasture lands
is mowing.
As mentioned previously, there was considerable emphasis on
the use of basic slag in England. On some soils superphosphate
was used. While the use of phosphorus and lime was emphasized
as necessary to correct soil deficiency on many pasture soils, the
wide use of nitrogen carrying fertilizers was rather surprising to
the American delegation. On some of the best pastures, very little
grain was fed, except to high producing milk cows. On poorer land
THE AMERICAN SOCIETY OF ANIMAL PRODUCTION
353
and especially on sandy types of soil, from 600 to 1,000 pounds of
a complete fertilizer per acre was used every two or three years,
with semi-annual applications of nitrogen.
The emphasis on artificial drying of hay seems to have shifted
rather completely to an attempt to dry very immature grass of
high protein and carotene content at lower cost. This is due to
recent experimental work on protein and vitamin value of immature grasses and to the inability of hay drier costs to compete with
the cost of improved haying machinery and hand labor in natural
drying. Few hay driers were seen in actual operation. In spite of
frequent rains the farm operators apparently follow the philosophy
that there is always a haying time. Much of the hay comes from
pasture land, r at her than from meadows being occasionally pastured. An inferior alfalfa field or meadow is quickly turned into
pasture by the addition of perennial rye grass, orchard grass, or
timothy.
Preservation of excess pasture growth with molasses instead of
with inorganic acids was another interesting trend. Some stack
silage made directly from pastures was observed in Holland. Small
pit silos filled with various field and pasture crops partially dried
were reported successful in Italy. Pressure for excluding air was
obtained with stones and dirt in these small silos.
Portable enclosures mounted on wheels and provided with corner wind breaks were used in sheep pasturing trials in Wales,
apparently with success. The same type of enclosure for use with
chickens was observed, and a portable shed for milking cows was
seen in England. Hurdles are still used, but no electric fences
were noticed. Tethering of horses, cows, and even brood sows was
seen. Definite rotational grazing is not widely practiced except on
dairy farms or with temporary crops.
At Rothamsted an 81-year-old check pasture still had a fair mat
of grass but no white clover. Phosphorus, potash, and basic nitrates had given increases in yield, but acid forms of nitrogen had
lowered yields and types of vegetation. At Market Harborough in
Leicestershire, 100-year-old pastures produced 280 pounds of beef
and 80 pounds mutton per acre per year. This was one of the best
pastures observed and was remarkably clean of weeds. Rye grass,
wild clover, and Poa formed the chief vegetation.
At Cockle P a r k the oldest grazing test was observed. Starting
in 1903, each of four 10.1-acre plots received 1,000 pounds of basic
slag per acre. These plots have been grazed each summer with
cattle and sheep. Results are given in Table I in pounds gain per
acre.
These results, as well as the older ones from the Tree Field,
which has been used for sheep alone since 1896, emphasize the
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TABLE I. Cockle Park Pasture Fertilization Test
(Hanging leaves fields)
Plot 1. 1,000pounds basic slag 1903;
500 pounds every third year
Plot 2. Same as 1 with 300 pounds
cottonseed meal annually
Plot 3. 1,000pounds basic slag 1903;
300 pounds cottonseed meal annually
Plot 4. Same as 2 except fish
guano used
Av. 1934-36
Cattle Sheep
Av. 1936
Cattle
Sheep
164.5
95.2
190.2
97.0
176.3
96.5
197.0
114.0
112.6
73.6
127.5
89.0
172.2
95.5
202.0
113.5
value of phosphorus in keeping up pasture yields. On the Tree
Field, in 1936, four times as much mutton per acre was produced
on the basic slag area as on the check pasture. Twenty-nine years'
results show that for every pound of increased weight per acre obtained on the Tree Field stocked with sheep, two pounds per acre
was secured on the plots stocked with cattle and sheep. In the last
seven years an average of 45 per cent m or e sheep gain has been
obtained with cattle than with sheep alone on similar pastures.
Near Newcastle a farm was visited that claimed 440 pounds beef
and sheep gain per acre. Yet, a few miles to the north a hill pasture
produced about 30 pounds gain per acre.
One's impression of England is that the best land is intensively
utilized and the poorer land retired from production. Increased
productivity of poor pastures furnishes competition to the best
English f ar mer in finishing livestock. The same rehalancing of
livestock production may take place in this country, where pastures can be improved without more cost than the value of the
increase in livestock products.
ELECTRIC QUICK DRIER FOR MOISTURE DETERMINATIONS
R. H. REED
I
The paper I have prepared will, I hope, make it easier for others
to design and construct quick drying units to fit their own particular needs. The details given and the calculations indicated are
presented on the assumption that no two driers of this general type
will ever be exactly the same, and that, therefore, the prospective
designer will be following principles rather than blueprints.
The electric quick drier for pasture samples was designed and
1Associate in Agricultural Engineering, Agricultural Experiment Station,
University of Illinois, Urbana.