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The critical constraint for profitable livestock production
in developing countries is the inadequacy of quality forage. Because
of ever growing human need for food, only limited cultivated land
can be allocated to fodder production. Due to low per acre yield
and minimum area under fodder production, the available fodder
supply is much less than actually needed. This shortage in fodder
supply is further being aggravated by increased urbanization and
enhanced shifting trend of agriculture towards cash crops which
further reduced the area under fodder crops by 2% after each decade.
Moreover in our region, low per acre fodder yield coupled with
two important fodder scarcity periods (one during summer and other
during winter months), which, further aggravated the fodder availability
situations.
Manipulating surplus fodder can go a long way to bridge this
wider gap between fodder supply and demand during scarcity periods.
Improvement in quality and quantity of feeds could result in the
improvement of livestock production up to 50% from existing genetic
potential of animals. So there is an immediate need to explore
the available feed resources for sustainable livestock production
and to suggest remedies to minimize the gap between nutrients
availability and requirements of animals. One of the important
feasible alternatives is to overcome the fodder shortage during
severe weather conditions or a prolonged drought is the silage
making of fodder when it is abundantly available. Preservation
of surplus fodder by silage making can help reduce this irregular
fodder supply pattern round the year.
Non-leguminous crops like corn, oat, barley, mott grass and jambo
grass have relatively low buffering capacity and low concentrations
of fermentable carbohydrates. Leguminous crops, on the other hand,
have high moisture content, high buffering capacity (due to high
protein and mineral content) and relatively low concentrations
of fermentable carbohydrates therefore, pH drop in leguminous
crops is also slow. Leguminous crops are extensively wilted prior
to ensiling to lower the moisture content either by field wilting
or by the addition of some absorbent. Dry roughages high in dry
matter, low in N content like wheat and rice straws can be added
successfully before ensilation. The information regarding the
nutritive value of Mott grass, Jambo grass, Berseem and Lucerne
plus wheat straw silage and its impact on lactation performance
of Nili-Ravi buffaloes is not available in the literature.
The objective of the present project was to examine the influence
of various additives, moisture levels and fermentation periods
on nutritive value of leguminous (Berseem and Lucerne) and non-
leguminous (Jambo and Mott grass) fodders and their silages and
their influence on feed intake, digestion kinetics, nutrient digestibility,
milk yield and its composition in lactating Nili-Ravi buffaloes.
The hypothesis was that silages of various fodders (Jambo, Mott,
Berseem and Lucerne) could successfully replace the conventional
fodders in buffalo diets without adversely affecting their lactation
performance.
The trials were conducted in three phases i.e. laboratory, in
situ and lactation performance phases. Samples of Jambo and Mott
grass fodders harvested at 50 days of maturity were analyzed for
dry matter (DM), crude protein (CP), neutral detergent fiber (NDF),
acid detergent fiber (ADF), acid detergent lignin (ADL), hemicellulose,
cellulose and ash contents. Jambo and mott grasses were ensiled
in laboratory silos using two silage additives, molasses and crushed
corn grains at 2, 4 and 6% of forage DM. The material in these
silos was allowed 30, 35 and 40 days fermentation periods. While,
berseem and lucerne fodders harvested at one tenth bloom were
ensiled in laboratory silos at 20, 30, 40% DM and fodder as such
(without wheat straw) each with three levels of molasses as additive
i.e. 2, 4 and 6% of forage DM. Wheat straw was added in different
proportions to increase DM of leguminous fodders. After opening
these silos, the pH and lactic acid concentration were measured
and thereafter these
silages were subjected to complete chemical analysis. Jambo grass
ensiled with 2% molasses for 30 days proved to be the best as
evidenced by low pH value and high lactic acid concentration.
The pH of all treatments ranged from 3.50 to 3.90 while, the lactic
acid concentration ranged from 3.86 to 4.10% but the results were
non- significant statistically. These results showed that fermentation
was predominantly of lactic acid an indication of well-preserved
and good quality silage. Dry matter, TP, NDF and hemicellulose
values were significantly affected by additive type being better
with molasses at 2% level. There was non-significant change in
CP, ADF, ADL, cellulose and ash contents during ensiling of jambo
grass. At all inclusion levels of corn and molasses, fermentation
periods did not affect the results. However, results indicated
that preservation of jambo grass was comparatively better with
a little loss of nutrients when it was ensiled with 2% molasses
for 30 days.
The pH and lactic acid of mott grass ensiled with molasses and
corn at all inclusion levels and fermentation periods were non-significant
across all treatment means. Similarly, DM, CP, TP, ash and cell
wall fractions (NDF, ADF, ADL, hemicellulose and cellulose) of
mott grass silage remained unaffected by additives, their levels
and fermentation periods. These results revealed that hydrolysis
of fermentable carbohydrates from both the additives were similar
during ensilation of mott grass. Therefore, being economical mott
grass ensiled with 2% molasses for 30 days was selected for subsequent
investigations.
Lactic acid and pH values of berseem ensiled at various DM contents
with all inclusion levels of molasses were non-significant across
all treatment means. Dry matter, CP, ash and cell wall fractions
(NDF, ADF, hemicellulose, cellulose and ADL) were significantly
affected by DM content at ensiling. However, the effect of additive
levels and the interaction between additive levels and DM content
were non-significant statistically. Regardless of additive levels,
results were significantly better for berseem ensiled at 30% DM.
Non-significant results of pH and lactic acid of lucerne silage
revealed that all the silages were preserved well in small-scale
laboratory silos. Dry matter, CP, NDF, ADF, hemicellulose, cellulose,
ADL and ash contents of lucerne silage were significantly affected
by DM content at ensiling while, the affect of additive levels
and DM at ensiling were non-significant. However, the results
of chemical composition were comparatively better when lucerne
was ensiled at 30% DM with 2% molasses.
For in situ digestion kinetics studies, a male buffalo bull fitted
with ruminal cannula was used of each study. Nylon bags measuring
10 23 cm with an average pore size of 50µm were used for
determination of digestion kinetics. These bags separately contained
10g samples of Jambo and Mott grass harvested at 50 days of maturity,
Berseem and Lucerne fodders harvested at one tenth bloom and their
best screened silages from laboratory studies. For each time point,
there were three bags for each sample. Two bags were used to determine
DM and NDF degradabilities while third was kept as a blank. These
bags were exposed to ruminal fermentation for 1, 2, 4, 6, 10,
16, 24, 36, 48 and 96 hours. After removal from the rumen, residues
in the bags were analyzed for DM and NDF.
Dry matter and NDF degradabilities (at 48 hours of incubation)
of jambo and mott grasses were significantly higher (p<0.05)
than that of their respective silages. Dry matter and NDF degradabilities
of berseem and its silage were non-significant different. However,
DM degradabilities of lucerne and its silage were non-significant
but NDF degradability of lucerne was significantly higher than
that of its silage. Dry matter and NDF lag time, rate and extent
digestion of jambo grass, mott grass, berseem and lucerne were
non-significant across their respective silages. The results showed
that all the silages were preserved well with minimum loss of
soluble carbohydrates and ensilation rather improve their digestibility.
For lactation trials each non-leguminous fodder (jambo and mott
grasses) was ensiled with 2% molasses for 30 days on large scale
in bunker silos. While, each leguminous fodder (berseem and lucerne)
was ensiled at 30% DM with 2% molasses. Wheat straw was added
to reduce moisture content of leguminous fodders. Fifteen, early
lactating Nili-Ravi buffaloes, five animals in each group, were
employed in a Completely Randomized Design for each leguminous
and non-leguminous study. Three experimental iso-nitrogenous and
iso-caloric diets were formulated that contained 75% of jambo
grass (control), jambo grass silage or mott grass silage and 25%
concentrate for non-leguminous fodders. While in case of leguminous
fodders, diets contained 75% of berseem fodder (control), berseem
or lucerne silage and 25% concentrate. The buffaloes were fed
for 60 days at ad libitum intakes. First 10 days were allowed
for dietary adaptation and 50 days were for sample collection.
Milk samples (a.m. & p.m.) were collected daily during the
last 7 days of feeding trial and were analyzed for CP, fat, solid
not fat and total solids. During last week of the study, a digestibility
trial was conducted. The acid insoluble ash was used as digestibility
marker.
Intake of DM was the highest (13.3 kg/d) in animals fed jambo
grass (control) diet followed by those fed jambo grass silage
(12.5 kg/d) and mott grass silage (12.03) diets. The difference
in DMI was significant across fodder and silage based diets but
the difference was non-significant across both silage-based diets.
The depression in DMI may be attributed to the presence of fermentation
products in the silage. However, DMI as a percent of body weight
was non-significant across all treatments. Crude protein intake
showed a similar trend across all treatments as was observed in
DMI. Intake of NDF (NDFI) was significantly higher (8.35 kg/d)
in buffaloes fed jambo grass diet followed by those fed mott grass
silage (7.99 kg/d) and jambo grass silage (7.32 kg/d) diets. Similar
trend was also noted for NDF intake as percent of body weight
and digestible NDF intake across all diets. The apparent digestibilies
of DM, CP and NDF did not show any treatment effect.
Dry matter intakes by lactating buffaloes differed significantly
across berseem fodder (control), lucerne silage and berseem silage
diets. Intake of DM was higher (13.8 kg/d) in animals fed berseem
fodder (control) diet followed by those fed lucerne silage (12.5
kg/d) and berseem silage (11.9 kg/day) diets. However, DMI as
a percent body weight was higher (3.24) in animals fed berseem
fodder diet followed those fed lucerne silage (2.89) and berseem
silage (2.63) diets. The difference in DMI percent body weight
was significant across fodder and silage based diets while these
results were non-significant across both silage-based diets. Digestible
DMI also followed the similar trend as was observed in DMI which
was higher (8.95 kg/day) in animals fed berseem fodder diet followed
by those fed lucerne silage (7.94 kg/day) and berseem silage (7.39
kg/day) diets. Similarly, CP intake and digestible CP intake also
showed a similar trend as was observed in DMI and digestible DMI
across all treatments. Intake of NDF was the highest (5.68 kg/d)
in buffaloes fed berseem fodder diet followed by those fed lucerne
silage (5.50 kg/d) and berseem silage (5.00 kg/d) diets. The difference
was significant across fodder and silage based diets but NDFI
was non-significant across both silage-based diets. Similar trend
was also noted for NDF intake as percent body weight and digestible
NDF intake across all diets. The apparent DMD was the highest
(64.8%) in animals fed berseem fodder diet followed by those fed
lucerne silage (63.4%) and berseem silage (62.0%) diets. The apparent
DMD was statistically significant across fodder and silage based
diets but DMD was non-significant across both silage-based diets.
However, apparent CP and NDF digestibilities remained unaltered
across all treatments.
Milk yield (4% FCM) was non-significant in animals fed leguminous
and non-leguminous fodders and their silages. Milk fat, total
solids, solid not fat, milk CP, TP and NPN values also remained
unaltered in animals fed non-leguminous fodder or silage diets.
These results may be attributed to insignificant variation in
DMI percent body weight and nutrient digestibility in animals
fed all experimental diets. However, milk fat and total solids
were significantly higher in animals fed berseem silage and lucerne
silage diets as compared to those fed berseem fodder (control)
diet. It was attributed to increased intake of structural carbohydrates,
which were degraded by cellulolytic microbes for the production
of acetate and milk fat. However, milk CP, TP, NPN and solid not
fat values did not show any treatment effect.
Grasses and legumes were ensiled with different additives at
various moisture levels for various fermentation periods, 2% molasses
proved to be best additive at 30% DM for 30 days. When these silages
were subjected to lactation performance study it was revealed
that despite low feed intake of silage there was not any depression
in milk yield and its composition. So replacing fodder with silage
no adverse effect was noted on the performance of lactating buffaloes.
Thus silage making of surplus fodders during their abundant growth
period will not only help overcome the irregular fodder supply
pattern, one of the major culprit for lower ruminant productivity,
but it will also enhance fodder yield of multicut fodder crops
by increasing their number of cuts.
Source: This article has previously been published in THE VETERINARY
NEWS & VIEWS [WEEKLY] and on World Veterinary Association
web site (March 25, 2004 at 02:09 PM). |
