ABSTRACT
The first study was carried out to determine the effects of
application of varied levels of fertilizer (NPK 15-15-15) and harvest time on yield
and chemical composition of Panicum maximum cv. Mombasa in Shika, Northern
Guinea Savannah of Nigeria.The experiment waslaid out in 4×3 factorial
arrangements in Randomised Complete Block Design (RCBD) with 3 replicates
(Blocks). The 2 factors were fertilizer levels (0, 200, 300 and 400 Kg/ha NPK
15-15-15) and harvest time (8, 10, and 12 weeks after planting, WAP). The fresh
and dry matter yields of Panicum maximum cv. Mombasa were influenced positively
with increasing levels of fertilizer and harvest time. Total dry matter
increased significantly (P<0.05) from 2.30 tonnes/ha in the control to 4.20
tonnes/ha in 400kg fertilizer applied treatment and total fresh weight also
increased significantly (P<0.05) with age, from 8.6 tonnes/ha at 8th week to
21.00 tonnes/ha at week 12 after planting. Results from the study revealed that
Crude protein content of the forage increased significantly (P<0.05) from
7.83% in the control (0kg/ha NPK) to 11.66% in treatment with 400kg/ha NPK.
Crude fibre decreased from36.94% in the controlto33.96% in treatment with
400kg/ha NPK. CP of Panicum maximum cv. Mombasa declined with maturity (from
10.29%at 8to 9.24% at 12 weeks after planting). CF and Ash’s percentages
increased (P<0.05) with age. DM, OM, CP and NFE of the forage were highest
in week 8 after planting and declined thereafter. ADF values indicated a
decrease as NDF values showed an increase as fertilizer levels were increased.
NDF and lignin content of the forage increased with age. P (from 1.46 g/kg at
in the control to 1.75 g/kg in treatment with 300kg/ha NPK) and K (from 4.73
g/kg at in the control to 8.42 g/kg in treatment with 300kg/ha NPK) content of
the forage was affected positively whereas Ca and Na did not change
significantly (P>0.05) with fertilization. It can be concluded that the
application of NPK (15-15-15) at the rate of 400kg/ha improved the nutritive
value and yield of Panicum maximum cv. Mombasa. Panicum maximum cv. Mombasa was
at its best nutritive value at8th week after planting but yielded more dry
matter at 12th week after planting. Thus, farmers are encouraged to apply NPK
(15-15-15) at 400kg/ha and harvest Panicum maximum cv. Mombasa at 10th week for
better forage in terms of nutritive value and yield. The second experiment was
conducted to investigate the effects of Concentrate inclusion levels on
nutrients digestibility and Nitrogen balance in Red Sokoto bucks fed Panicum
maximum cv. Mombasa based diets. The Concentrate inclusion levels were 15, 30,
45 and 60 % (Treatments 1, 2, 3 and 4, respectively). Twelve (12) Red Sokoto
bucks were randomly assigned to the four treatments in a Completely Randomised
Design (CRD).Dry matter digestibility was significantly (P<0.05) higher in
bucks fed diet containing 60% Concentrate (75.21%) compared to the other three
Treatments. Bucks fed diet containing 60% Concentrate had the highest
(P<0.05) Organic matter digestibility (75.32%) compared to the other
Treatments. Nitrogen free extract and Neutral detergent fibre digestibility
followed a similar pattern of change as in Organic matter. Bucks fed Treatments
with 45 and 60% Concentrate inclusion showed significantly (P<0.05) higher
ether extract digestibility compared to those fed 15 and 30 %. Crude fibre
digestibility was significantly (P<0.05) higher in bucks fed diet containing
30% Concentrate (84.59). Treatments 3 and 4 were similar, whereas Treatment 1
recorded the lowest (68.74%) crude fibre digestibility. Crude protein
digestibility increased with increasing Concentrate levels. Highest
(P<0.05)CP digestibility values were observed in bucks fed diet containing
60% Concentrate (81.77%) while bucks fed diet containing 15% Concentrate
recorded the least values. Acid detergent fibre digestibility followed a trend
similar to that of crude protein. Nitrogen intake increased significantly
(P<0.05) with an increase in Concentrate levels. Bucks fed diet containing
60% Concentrate (8.36g/day) were significantly higher (P<0.05) in Nitrogen
intake. Faecal nitrogen loss decreased significantly (P<0.05) as Concentrate
inclusion levels increased (from 1.52 g/day in treatment with 60% Concentrate
to 2.32 g/dayin treatment with 150%), while Urine nitrogen loss followed a
trend opposite to that of faecal nitrogen loss. The highest (P<0.05) Total
Nitrogen excreted was observed in treatment 3 (3.00g/day). Nitrogen retained
was similar in bucks fed diet containing 30 and 60% Concentrate but was
significantly higher (P<0.05) in bucks fed diet containing 15 and 45%
Concentrate. Nitrogen absorbed as a percentage of intake and Nitrogen retained
as a percentage of intake followed the same pattern. Bucks fed diet with 60%
Concentrate inclusion were significantly higher (P<0.05) while bucks fed
diet containing 15 and 45% Concentrate were lower in these parameters. In
conclusion, the inclusion of Concentrate in Panicummaximum cv. Mombasa based
diet increased the diet’s intake, digestibility and Nitrogen retention in Red
Sokoto bucks. It is therefore recommended that farmers could incorporate 60%
Concentrate in a Panicummaximum cv. Mombasa based diet for improved
digestibility and nitrogen retentionin Red Sokoto bucks.
CHAPTER ONE
1.0
Introduction
Nigeria is an agricultural country with diverse vegetation,
varying from rainforest to the Sahel. About 32.42 million hectares of grazing
land and 39.41 million hectares of cropland in Nigeria provide a substantial
amount of feed for the country’s livestock(Shiawoya and Tsado, 2011). The
savannah zone is home to about 80% of ruminant livestock population.
Availability and quality of feed stuff are major constraints in the development
of the livestock industry in this region. Extensive areas of the grazing lands
are composed of indigenous species, which are of low quality (Shiawoya and
Tsado, 2011). There is a wide variation in the quality and quantity of pasture
available from one time of the year to another (Adamu, 2015). Hence, there is
need to develop or adopt strategies, or technologies to provide
highqualityforage for livestock in this region.
Several forage species, especially grasses have been
introduced into Shika, Northern Nigeria and screened for productivity and
adaptively over the past years. This has been in search of outstanding
materials that could be used to partially or completely replace the low
productive native grassland species (Whiteman, 1980). In some of the screening
trials, Agishi (1978) on upland and Akinola and Olorunju (1990) on lowland
reported some forage species that are well adapted to the Northern Guinea
Savannah and produced a substantial amount of forage biomass.
There are many grass species that are used for pasture in
the tropics and subtropics due to their high dry matter yields and good animal
feed quality. Panicum maximum is one of these extensively used forage grasses
(Correa and Santos, 2003). Panicum maximum (Guinea grass) is a native of
tropical Africa, extending to the sub-tropics of South 1
Africa. It occurs at forest edges in the bush, as a pioneer
grass covering the land cleared from the forest and in grassland with scattered
trees where it tends to grow in high shades under trees (Whiteman, 1980).
Proper soil fertility management and understanding the nutritional requirement
of this grass species are extremely important for pasture management, which is
reflected by higher feed yield and their availability for animals. The use of
inorganic fertilizers can significantly increase forages production, providing
greater capacity and thus resulting in higher milk and meat production per unit
of area used (Pereira et al., 2011; Iwanmoto et al., 2015). The increased yield
due to fertilizer application could be attributed to increased in both leaf
production, increased number of tillers and photosynthesis directly (Aderinola
et al., 2011).Dry matter yield also generally increases with increasing
fertilizer rates (Carvalho et al., 2000; Adewumi, 2013). Fertilization enhances
nutrient digestibility, which canimprove livestock Production (Peyraud and
Astigarraga, 1998). Fertilizer contributes to the greater productivity of
Mombasa Guinea Grass by increasing production per cycle and the number of
harvest cycles (Pereira et al., 2012; Hare etal., 2015). Increasing rates of
nitrogen significantly increased CP and NDF concentrations in stems and leaves
and; ADF concentrations in stems (Peyraud and Astigarraga, 1998; Adewumi, 2013;
Hare et al., 2015) andreduction in the crude fibre content of stem (Onyeonagu
et al., 2012).In addition, it can also provide other supplementary effects that
will increase the efficiency of the system as a whole, such as the production
of soilage or hay to be used during the dry season (Cecato et al., 2001). Stage
of maturity also affects the quality and quantity of Panicum maximum. Dry
Matter yield increases with advancing maturity, but quality declines (Taute et
al,2002). Onyeonagu (2012) noted that cutting interval and fertilizer
application havesignificant influence on the chemical composition of Panicum
maximum forage.
Ruminant production is one of the major livestock activities
in most of the developing countries in the tropics (Okoruwa and Agbonlahor,
2016). Ruminant livestock play an important role in the economic development of
Nigeria in terms of feeding the steadily growing population and providing the
investible resources for national development (Bolaji et al., 2016).Over the
years, there has been a great increase in the production of goats in Nigeria
which has resulted in poverty alleviation and the supply of high-quality animal
protein in order to meet the demand of the teeming population (Ibrahim et al.,
2014). Goats are classified as an important small ruminant on account of their
unique ability to adapt and maintain themselves in a harsh environment. (Bolaji
et al., 2016). Goats are one of the most prolific of all domesticated ruminants
under tropical and subtropical conditions (Webb and Mamabolo, 2004) and their
small size relative to cattle contributes to their wide distribution and easy
management among Farmers. (Bolaji et al., 2016). The Red Sokoto, is the most
important goat breed in Nigeria, accounting for about 70% of the estimated 34.5
million goats in Nigeria (Osuhor et al., 1998). Animal protein is one of the
most important components of human diet and its consumption varies from country
to country (Okai et al., 2005). Goats as a multipurpose animal are a major
source of milk, skin and manure apart from meat. Goats also provide income for
meeting household needs (Peacock et al ., 2005). Nigerian small ruminant
industry is faced with the problem of meeting the nutritional requirements of
the animals (Jones and Wilson, 1987; Fasae et al., 2005). Goats in Nigeria
suffer several nutritional stresses in the dry season as a result of seasonal
variability that affects the availability and nutritive quality of pastures
which in turn causes marked decrease in nutrient intake and performance of the
animal (Bolaji et al., 2016).Therefore, study on the effects of fertilizer and
harvest time on Panicum maximumcv. Mombasa and Concentrate inclusion levels in
Panicum maximumMombasa based diets isvery important.