Department of Animal Sciences

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Grazing Behaviour of Saanen and Toggenburg Goats in Sub-Humid Tropical Conditions of Kenya
(2001-03-22) Njoka-Njiru, E. N. *; Ojango, J. M.; Ambula, M. K.; Ndirangu, C. M.
The behavior of 6 Toggenburg and 6 Saanen female goats, grazing on natural vegetation in a modified sub-humid tropical environment of Kenya, was studied during the dry (January and February) and wet (April and May) seasons in 1997. The two exotic breads grazed for 12 h daily. Observation on feeding, standing, lying and ruminating was done chronometrically at five minute intervals between 0600 and 1800 h. These grazing times were based on the current practice of small holder farmers. During the dry period, the average feeding standing, lying and ruminating time per 12 h period for Saanens was 5.63, 4.57, 1.80 and 1.50 h respectively while that for Toggenburgs was 7.26, 3.21, 1.53 and 1.96 h, respectively. In the wet (Green) season, the mean feeding, standing, lying and ruminating time per Saanen in both seasons. It was also observed that standing occurred more often in Saanens than the Toggenburgs in the dry season. During the wet period, Saanens ruminated significantly longer than the Toggenburgs. The health status of the animals was determined by analyzing the respiratory frequency, heart rate, rectal temperature, hemoglobin, erythrocytes and leucocytes of the experimental animals. All the clinical and physiological parameters were within the normal physiological range of healthy goats. It was concluded that differences in the grazing behavior of Saanens and Toggenburgs in the modified tropical environment of Kenya, do exist.
Evaluation of Sorghum (Sorghum bicolor) as Replacent for Maize in the Diet of Growing Rabbits (Oryctolagus cuniculus)
(2002) Muriu, J. I.; Njoka-Njiru, E. N. *; Tuitoek, J. K.; Nanua, J. K.
Thirty six young New Zealand white rabbits were used in a randomised complete block (RCB) design with a 3×2 factorial treatment experiment to study the suitability of sorghum as substitute for maize in the diet of growing rabbits in Kenya. Six different diets were formulated to contain 35% of one of the three different types of grain (maize, white sorghum or brown sorghum) and one of the two different levels of crude protein (CP) 16 or 18.5% and fed to growing rabbits for a period of six weeks. The tannin content of the grains was 0.05, 0.52 and 5.6% chatechin equivalents for maize, white and brown sorghum respectively. Weaning weight at 35 days of age was used as the blocking criterion at the beginning of the experiment. Results of feed intake, weight gain, feed conversion efficiency, feed digestibility, as well as the blood parameters, indicated that white sorghum was not significantly different from maize. Animals fed on diets containing brown sorghum had a lower average daily gain (ADG) and a poorer feed conversion efficiency (FCE) (p<0.01) in comparison with those fed on diets containing maize or white sorghum. The 18.5% CP level gave a better FCE (p<0.05) compared with the 16% CP level. However, increasing the level of CP did not improve the utilisation of any of the grains. It was concluded that white sorghum could effectively substitute maize in the diet of growing rabbits. On the other hand, the use of brown sorghum in the diets of growing rabbits may compromise their growth rate. This may be due to the high concentration of tannins in the brown sorghum
Effect of Intercropping Herbaceous Legumes with Napier Grass on Dry Matter Yield and Nutritive Value of the Feedstuffs in Semi-arid Region of Eastern Kenya
(2006) Njoka-Njiru, E. N.; Njarui, M. G.; Abdulrazak, S. A.; Mureithi, J. G.
Semi-arid region of Kenya is faced with inadequate quantity and low quality of livestock feeds. Research was conducted in the semi-arid region of eastern Kenya to investigate the contribution of two legumes, Seca (Stylosanthes scabra cv. Seca) and Siratro (Macroptilium atropurpureum cv. Siratro) to seasonal total fodder productivity and nutritive value when intercropped with Napier grass (Pennisetum purpureum cv. Bana). The treatments consisted of Napier grass planted as pure stand and intercropped with legumes. During the production phase, the grass and legumes were harvested for dry matter yield after every 8 weeks for a period of four wet seasons and two dry seasons between April 2002 and September 2004. Overall total herbage yield of the mixtures was higher than those of sole fodder grass with the grass constituting the major component of the yield. Seca was more productive and had a relatively stable yield than Siratro. It accounted for higher proportion of total DM yield of 15 - 34%. in Napier compared to Siratro which had less than 5% except in the drier season when yield failed. Total DM yield was highest during the short rains of year 2002 and declined thereafter in subsequent seasons and was lowest during the dry seasons. It was observed that crude protein of Napier grass was significantly ( P< 0.05) enhanced by inclusion of the legume in the intercrop (CP 9.64 - 9.96% of DM) compared to sole Napier grass (CP 8.14% of DM). Napier grass intercropped with Seca was more degradable than sole Napier grass. It can be concluded that Seca formed a better association with fodder grass than Siratro and is recommended for intercropping in the semi-arid region of eastern Kenya.
Effects of Mineral Supplementation On Milk Yield of Free-ranging Camels (Camelus dromedaries) in Northern Kenya.
(2006-11) Onjoro, P. A.; Njoka Njiru, E. N. *; Ottaro, J. M.; Simon, A. 1; Schwartz, H. J. 1
ABSTRACT : The effects of different mineral supplementations on the milk yield of free-ranging Somali camels were investigated in two phases in a semi-arid region of northern Kenya during the dry and wet seasons in 2002 and 2003. In phase 1, twelve (12) lactating camels were selected at random to form four (4) groups each consisting of three camels. The first group served as the control and as a result received no mineral supplementation. In addition to the control diet the other groups received oral doses of minerals as follows over a 60-day period: T1 (P), T2 (High Cu low Co) and T3 (Low Cu high Co). The daily milk yield and blood mineral profiles were measured during the wet and dry seasons. The mean daily milk yield increased from 3.4 L/d to 4.3±0.3 L/d and 5.2 L/d in the dry and wet seasons, respectively. Fifteen (15) lactating camels were selected at random to form five groups each consisting of three replicates. The control group did not receive any mineral supplement. The other four groups in addition to the control diet, received the following treatments: T4 (Common Salt), T5 (High Co), T6 (High Co+P) and T7 (Low Co+P). Mineral supplement T6 produced significantly higher milk yield (5.4±0.5 and 6.5±0.7 L/d) during the dry and wet seasons. Both T6 and T7 had significantly higher milk yield than T4 and T5. During both phases, the blood Ca and P level significantly increased in camels receiving T1, 6 and 7. Animals that received only the trace mineral supplements had lower blood P compared to the ones receiving supplementary P and also the control. Supplementation of lactating camels with Co and P significantly (p<0.05) increased milk yield). Effect of common salt, commonly given by farmers, on milk yield was insignificant. It was concluded that mineral supplementation to lactating camels was beneficial, and that mineral supplements should include P and Co. Further research is required to establish P and Co requirements of lactating camels. (1) (PDF) Effects of Mineral Supplementation on Milk Yield of Free-ranging Camels (Camelus dromedarius) in Northern Kenya. Available from: https://www.researchgate.net/publication/260087255_Effects_of_Mineral_Supplementation_on_Milk_Yield_of_Free-ranging_Camels_Camelus_dromedarius_in_Northern_Kenya [accessed Nov 20 2019].
Effects of minerals in the forage, blood and milk on production of lactating free-ranging camels (Camelus dromedaries) in northern Kenya.
(2006-11) Onjoro, P. A.,; Njoka-Njiru, E. N.,; Ottaro, J. M.; Nanua, J. N.
The effects of different mineral supplementations on the milk yield of free-ranging Somali camels were investigated in two phases in a semi-arid region of northern Kenya during the dry and wet seasons in 2002 and 2003. In phase 1, twelve (12) lactating camels were selected at random to form four (4) groups each consisting of three camels. The first group served as the control and as a result received no mineral supplementation. In addition to the control diet the other groups received oral doses of minerals as follows over a 60-day period: T1 (P), T2 (High Cu low Co) and T3 (Low Cu high Co). The daily milk yield and blood mineral profiles were measured during the wet and dry seasons. The mean daily milk yield increased from 3.4 L/d to 4.3±0.3 L/d and 5.2 L/d in the dry and wet seasons, respectively. Fifteen (15) lactating camels were selected at random to form five groups each consisting of three replicates. The control group did not receive any mineral supplement. The other four groups in addition to the control diet, received the following treatments: T4 (Common Salt), T5 (High Co), T6 (High Co+P) and T7 (Low Co+P). Mineral supplement T6 produced significantly higher milk yield (5.4±0.5 and 6.5±0.7 L/d) during the dry and wet seasons. Both T6 and T7 had significantly higher milk yield than T4 and T5. During both phases, the blood Ca and P level significantly increased in camels receiving T1, 6 and 7. Animals that received only the trace mineral supplements had lower blood P compared to the ones receiving supplementary P and also the control. Supplementation of lactating camels with Co and P significantly (p<0.05) increased milk yield). Effect of common salt, commonly given by farmers, on milk yield was insignificant. It was concluded that mineral supplementation to lactating camels was beneficial, and that mineral supplements should include P and Co. Further research is required to establish P and Co requirements of lactating camels.
Effect of Planting Pattern of Two Herbaceous Forage Legumes in Fodder Grasses on Productivity of Grass/Legume Mixture in Semi-arid Tropical, Kenya.
(Universidad Autónoma de Yucatán, 2007-01) Njarui, D. M. G. 1; Njoka, E. N. 2; Abdulrazak, S. A. 2; Mureithi, J. G. 3
An experiment was conducted to investigate the effect of planting pattern of legumes on the growth, persistence and productivity of grass/legume mixture in the semi-arid tropical Kenya. The legumes, Seca and Siratro were planted either as single or double rows between rows of Napier grass and giant panicum. Plant population, growth and productivity of the mixture were monitored for a period of 4 wet seasons; short rains (SR) 02, long rains (LR) 03, SR 03 and LR 04 and two dry seasons (DS) 03 and DS 04. There was significantly (P<0.05) more plants that survived from double rows of legumes (15 plants m-2) than from single rows (10 plants m-2). Legumes planted in double rows between grass rows covered more plot than when planted in single rows with Siratro covering more plot than Seca. However, legumes planted in double rows had no significant (P<0.05) dry matter (DM) yield advantage over single rows and did not benefit or impede growth (tiller and canopy cover) of the fodder grasses. The productivity of the associated fodder grasses was not affected and hence combined total DM yield (grasses + legumes) were not significantly different. Napier grass was more vigorous, had more tillers, large canopy and consequently was more productive than Panicum. On the basis of combined DM production, Napier grass/Seca was most productive while Napier intercropped with Siratro and Panicum intercropped with either Seca and Siratro showed similarity in DM. Seca was more productive than Siratro and overall the proportion of the legume to total DM was highest during the dry season than wet season. Dry matter was highest during the SR 02 and declined progressively with seasons and was lowest during the dry seasons.
Evaluation of manure from goats fed Panicum basal diet and supplemented with Madras thorn, Leucaena or Gliricidia.
(2008) Saha, Hemedi Mkuzi; Kahindi, R.K.; Muinga, R.W.
An experiment was carried out to assess the effect of supplementing a Panicum hay basal diet with leaves of Madras thorn (Pithecellobium dulce), Leucaena (Leucaena leucocephala) or Gliricidia (Gliricidia sepium) on the quality and quantity of goat manure. Twelve Small East African goats aged eight months on average and weighing 9.7kg (±1.52) were randomly assigned to four treatments. Panicum hay fed ad libitum plus 100g of maize bran constituted the control diet. The remaining three treatments consisted of the control diet supplemented with iso-nitrogenous levels of Leucaena, Gliricidia or Madras thorn, respectively. Crude protein concentrations in the forages were 3.5, 21, 23 and 25% for Panicum hay, Gliricidia, Madras thorn and Leucaena, respectively. The supplements were therefore offered at 19.5g DM/kgW0.75 Madras thorn, 18.6g DM/kgW0.75 Leucaena and 22.5g DM/kgW0.75 Gliricidia. Daily total dry matter intake increased significantly (P<0.05). On supplementation from 229 for the control diet to 365, 387 and 398g for the diets supplemented with Madras thorn, Gliricidia and Leucaena, respectively. Animals supplemented with the legumes retained (p<0.05)mMore N (3.5, 3.6 and 3.7g N/day for Leucaena, Gliricidia and Madras thorn, respectively) than the control treatment (0.6 g N/day). Legume supplementation increased (p<0.05) daily weight gains from 2g per day for the control treatment to 19, 22 and 25g per day for diets supplemented with Gliricidia, Madras thorn and Leucaena, respectively. The effect of supplement on growth rate was not different between the legumes. Goats fed on legume supplements produced (p<0.05) more faeces (135g, 142g and 150g DM per day for goats fed Madras thorn, Gliricidia and Leucaena treatments, respectively) than those on the control diet (92g DM). The daily faecal DM outputs expressed as percentage of body weight were 1.13, 1.27 and 1.30% for the control diet supplemented with Madras thorn, Gliricidia and Leucaena, respectively, as compared with 0.98%, for the control diet alone. Legume supplementation in goats increased (p<0.05) faecal N content from 0.2 to 1.7% but had no effect on the C, P or K contents. Supplementation of a poor quality basal diet with legume forage is therefore recommended since, in addition to improving the performance of goats, it would increase the amount of manure produced and improve its quality.
Performance of growing Small East African Goats offered Rhodes grass hay and supplemented with a 1:1 mixture of Maerua angolensis: Zizyphus mucronata leaf browses.
(Livestock Research for Rural Development 22 (9) 2010, 2010) Ondiek, J. O. *; Abdulrazak, S. A. ***; Njoka, E. N. ***
A 56-day experiment was conducted to examine the contribution of Maerua angolensis and Zizyphus mucronata, mixed on a 1:1 ratio as a supplement to growing Small East African Goats fed a basal diet of Chloris gayana hay. Twenty goats were assigned to five treatments of: 0, 15, 20, 25 and 30 g DM kg-1W0.75, assigned as MZ0, MZ15, MZ20, MZ25 and MZ30. The total extractable phenolics (TEPH) and total extractable tannins (TET) for Maerua angolensis (11.4, 3.01 mg kg-1 DM) were lower than for Zizyphus mucronata (72.3, 41.2 mgkg-1DM) and the mixture had average values (41.9, 22.1 mg kg-1 DM), respectively. The Chloris gayana hay had low crude protein content (54 g kg-1 DM). Intake of hay and of total DM, and coefficients of apparent digestibility of diet proximate components, increased with supplementation. The control animals (MZ0) lost weight and the supplemented groups gained weight with best growth on the MZ20 diet. Rumen pH was in the normal range but rumen ammonia N was low for the control diet (8.99 mg 100ml-1), increasing with supplementation to 11.3 - 12.7 mg 100ml-1. There was a positive linear relationship between rumen ammonia level and live weight change. It is concluded that the 1:1 mixture of Maerua angolensis:Zizyphus mucronata with a CP of 261g kg-1 DM is an adequate protein supplement for growing Small East African Goats when fed a low quality (5.4% CP) basal diet of Chloris gayana hay.
Chemical and mineral composition, in-vitro gas production, in-sacco degradation of selected indigenous Kenyan browses
(CIPAV Foundation, 2010) Ondiek, J . O.; Abdulrazak, S. A. *; Njoka, E. N. **
Abstract Proximate and mineral composition, in-sacco degradation and in-vitro gas production was conducted using fifteen indigenous Kenyan multipurpose tree and shrub (MPTS) leaf browse to assess their potential as goat feed. The species selected from a field survey were Maerua angolensis, Acacia brevispica, Acacia mellifera, Acacia tortilis, Acacia hockii, Zizyphus mucronata, Grewia bicolor, Acacia elatior, Acacia nilotica, Balanites aegyptiaca, Acacia senegal, Acacia abyssinica, Bridelia micrantha, Albizia amara and Albizia coriaria. The CP levels ranged from 112gkg-1DM for Bridelia micrantha to 321 gkg-1DM for Maerua angolensis; the NDF ranged from 218 to 601 gkg-1DM for Acacia hockii and Albizia amara, respectively. The TEPH and TET were in the range of 1.52-26.4 and 0.301-24.4gkg-1DM, respectively. The major minerals Ca, P, Mg, Na and S were in the ranges of 6.51-28.1, 0.838-3.18, 0.442-8.51, 0.318-0.711 and 1.12-2.45gkg-1DM, respectively. The microelements varied widely (mgkg-1DM) as follows: Fe (51.3-267), Mn (13.8-38.5), Cu (4.81-74.9), Mo (13.9-43.4), Co (1.76-17.4), Zn (12.2-93.2) and Se (19.5-124). In-sacco DM degradation at 48hrs shows Zizyphus mucronata was highest followed by Maerua angolensis with degradability of 93.3% and 88.6%, respectively. Gas production (volume (ml)/200mgDM) levels (a+b) ranged from 19.2 to 52.2 in Bridelia micrantha and Maerua angolensis, respectively. The overall levels of nutrients and degradation showed variations but most of the forages were moderate to high in the nutrient composition and degradability parameters. The ranking of the forages in order of increasing nutritive value into three categories of five species was as follows: low (Bridelia micrantha< Albizia amara< Acacia hockii < Acacia nilotica< Acacia tortilis); medium (Acacia abyssinica< Grewia bicolor< Albizia coriaria< Acacia elatior) and high (Balanites aegyptiaca< Acacia mellifera< Acacia senegal< Zizyphus mucronata< Maerua angolensis). It is concluded that Maerua angolensis and Zizyphus mucronata are outstanding and they have potential for ruminant feed and more so as protein supplements to low quality tropical basal diets.
Effects of Supplementing Chloris gayana Hay and Maerua angolensis with Graded Levels of Maize Germ Meal on Voluntary Feed Intake, Diet Digestion, Nitrogen Balance and Average Daily Gains of Growing Small East African Goats
(2010-07) Ondiek, James; Abdulrazak, Shaukat; Njoka, E. N.
Maerua angolensis and graded levels of maize germ meal were offered to Small East African goats to assess the effects on voluntary feed intake, diet digestion, nitrogen balance and growth. The M. angolensis was offered at a rate of 20 g kg-1 W0.75 to all animals and maize germ meal treatment diets was given at five graded levels (0, 15, 20, 25, and 30 gDM kg-1 W0.75) designated as MG0, MG15, MG20, MG25 and MG30, in a completely randomized block design with 4 animals per treatment with the basal diet of Rhodes grass (Chloris gayana) hay fed ad libitum. The CP levels were 320, 200 and 61.4 g kg-1 DM for M. angolensis, maize germ and C gayana hay, and NDF contents were 449, 393 and 528 g kg-1 DM, respectively. The DMI was 461-599 g DM d-1 which increased with energy supplementation (P<0.05) although the supplemented groups did not differ and the goats consumed the feed at 3.72-4.53% of their live weight. The ADG was 4.92, 23.7, 26.4, 34.4 and 35.7 g d-1, respectively, with MG25 and MG30 being similar (P>0.05). The rumen NH3-N was in the normal range of 1.85-2.63 mg100 ml-1 while the nitrogen balance was in the range of 2.90-7.68 mg N/100 ml for MG0 and MG30, respectively. The DM, OM, CP, ADF and NDF digestibility was improved with supplementation, but supplemented animals had similar values (P>0.05). It is concluded that the maize germ meal supplemented at 25 g DM kg-1 W0.75 had high rumen NH3-N, N-retention and ADG 8.16 mg-1 100 ml, 6.25 g Nd-1 of 34.4 g d-1, respectively, and this can be used together with M. angolensis at 20 g DM-1 W0.75 to make use of the tree forage and low quality basal diet for growing Small East African Goats.
Optimizing the design of small-sized nucleus breeding programs for dairy cattle with minimal performance recording
(Elsevier, 2014) Kariuki, C. M.; Komen, H.; Kahi, A. K.; Van Arendonk, J. A. M.
7963J. Dairy Sci. 97 :7963–7974http://dx.doi.org/ 10.3168/jds.2014-8545 © American Dairy Science Association®, 2014 .ABSTRACT Dairy cattle breeding programs in developing coun-tries are constrained by minimal and erratic pedigree and performance recording on cows on commercial farms. Small-sized nucleus breeding programs offer a viable alternative. Deterministic simulations using se-lection index theory were performed to determine the optimum design for small-sized nucleus schemes for dairy cattle. The nucleus was made up of 197 bulls and 243 cows distributed in 8 non-overlapping age classes. Each year 10 sires and 100 dams were selected to pro-duce the next generation of male and female selection candidates. Conception rates and sex ratio were fixed at 0.90 and 0.50, respectively, translating to 45 male and 45 female candidates joining the nucleus per year. Commercial recorded dams provided information for genetic evaluation of selection candidates (bulls) in the nucleus. Five strategies were defined: nucleus records only [within-nucleus dam performance (DP)], progeny records in addition to nucleus records [progeny test-ing (PT)], genomic information only [genomic selection (GS)], dam performance records in addition to genomic information (GS+DP), and progeny records in addition to genomic information (GS+PT). Alternative PT, GS, GS+DP, and GS+PT schemes differed in the number of progeny per sire and size of reference population. The maximum number of progeny records per sire was 30, and the maximum size of the reference population was 5,000. Results show that GS schemes had higher responses and lower accuracies compared with other strategies, with the higher response being due to short-er generation intervals. Compared with similar sized progeny-testing schemes, genomic-selection schemes would have lower accuracies but these are offset by higher responses per year, which might provide addi-tional incentive for farmers to participate in recording.
Energy and amino acid digestibility of camelina meal fed to growing pigs.
(Elsevier, 2014-07) Kahindi, Roseline Kafedha; Woyengo, Tofuko A; Thacker, Palak B.; Nyachoti, C.M.
This experiment was conducted to determine the apparent (AID) and standardized ileal digestibility, (SID) of crude protein (CP) and amino acids (AA), the digestible (DE), metabolizable (ME) and calculated net energy (NE) values of screw-pressed camelina cake (SPCC) fed to growing pigs. Six ileal cannulated barrows [(Yorkshire-Landrace) × Duroc] with an average BW of 80 kg were assigned to two experimental diets in a two period crossover design to give six observations per diet. Each period lasted for 10 d; the initial 5 d for diet adaptation, followed by 3 d for urine and feces collection, and 2 d for ileal digesta collection. Pigs were fed either a corn–soybean meal basal diet formulated to meet NRC (1998) (Nutrient Requirements of Swine, 10th ed. National Academic Press, Washington, DC) nutrient requirements for 50 to 80 kg pigs or the basal diet with a portion of the corn and soybean meal replaced by 200 g/kg SPCC. The daily feed allowance was set at 40 g/kg BW at the beginning of each period and offered in two equal portions at 0800 and 1600 h. Titanium dioxide (3 g/kg) was included as an indigestible marker. The AID and SID of CP and AA as well as DE and ME values in SPCC were determined by the difference method. The SID of CP and AA was calculated using published values for basal endogenous AA losses obtained from our laboratory and NE was calculated using the determined components from chemical analyses. The GE, CP, lysine, methionine, threonine, ether extract, NDF, ADF and glucosinolate contents of SPCC (on a DM basis) were 21.5 MJ/kg, 381, 18, 6.8, 16.8, 119, 315, 203 g/kg and 36.3 μmol/g, respectively. The SID coefficient of CP for SPCC was 0.65. The coefficient of SID of lysine, methionine and threonine for SPCC were 0.58, 0.53 and 0.53, respectively. The DE, ME, and calculated NE values of SPCC were 17.5, 16.2 and 10.2 MJ/kg, respectively. In conclusion, SPCC has potential as an energy source given its remaining oil content, however, its digestibility coefficients for AA and CP were low, and could limit its utilization in swine diets. The SID AA, DE, ME, and calculated NE values of SPCC obtained from the current study could be used when formulating diets and to obtain predictable animal performance.
Assessing the influence of knowledge of type and numbers of livestock exchange in stock friends’ concept as a strategy in poverty alleviation; case of Ngomeni Community of Mwingi District in Kenya
(2015) M’mboroki, Kiambi G. 1; Aboud, Abdillahi A. 2; Rithaa, Jafford N. 3
One of the challenge-facing Kenya is high levels of poverty. Different ways of poverty alleviation are applied among them is stock friends strategy. The strategy is ineffective among the Ngomeni community of Mwingi District. It is postulated that there is poor understanding of the right types and numbers of livestock for the exchange; and the rate of adoption of the strategy. A socio-ecological survey of 233 households sampled and complemented by Key Informant interviews was conducted. Descriptive and regression analyses using SPSS were used to determine the associations and influences of the factors (independent variable) on poverty levels of the community (dependent variable). The degree of community knowledge of type and numbers of stock used in the stock exchange (β value of -0.449 that explained 25.5% variation) and adoption of the stock exchange strategy were found to be key and could be addressed using stock friend’s concept.
Characterization of clays from Tharaka-Nithi County in Kenya for industrial and agricultural applications
(2015) Njoka, E. N.; Ombaka, O.; Gichumbi, J. M.; Kibaara, D. I.; Nderi, O. M.
Clay samples from Tharaka-Nithi County in Kenya were characterized by hydrometer, X-ray fluorescence spectroscopy (XRF), atomic absorption spectroscopy (AAS), TGA, scanning electron microscopy (SEM) and powder diffraction (XRD) methods. The F-test and t-test were used to interpret the results. The major oxides present were Al2O3, SiO2 and the minor ones were CaO, TiO2, MnO, Fe2O3, K2O, MgO and Na2O. The values of SiO2 were greater than those of Al2O3, indicating that the samples were of clay minerals. The clay minerals with low cation exchange capacity (CEC) were present in the samples. The Atterberg limits showed that the inorganic clays of either low or intermediate plasticity having low contents of organic matter were present in the samples. The analysis further showed the availability of essential elements necessary for plant growth. The TGA analysis indicated that the decomposition of clay samples occurred in four steps. The scanning electron microscope photographs revealed that the samples contained a mixture of minerals of morphologies with crystallinity, high porosity and unstable under the electron beam. The major impurity in the clay is quartz, ranging from 22.6-31.9%. Albite is the most dominant component in the clay minerals contributing to 30.3 to 44.1%. The clay from the study area can be used as agro mineral additive to enhance soil fertility for crop production, a fluxing agent in ceramics and glass applications and also as functional fillers in the paint, plastic, rubber and adhesive industries after beneficiation.
Nutrient digestibility in diets containing low-phytate barley, low-phytate field pea and normal phytate field pea, and the effects of microbial phytase on energy and nutrient digestibility in the low and normal-phytate field pea fed to pigs
(Elsevier, 2015-05) Kahindi, R. K. a; Thacker, P. A. b; Nyachoti, C. M. a
Five ileal cannulated barrows (43.6 ± 1.3 kg BW) were used in a 5 × 5 Latin square design experiment to determine the apparent (AID) and standardized (SID) ileal digestibility of N and amino acids (AA) in low-phytate field pea (LPP), low-phytate barley (LPB) and normal-phytate field pea (NPP) and the apparent total tract digestibility (ATTD) of Ca, P and energy in diets containing these ingredients. In addition, the effects of phytase supplementation (500 FTU/kg) to diets containing LPP or NPP were determined. The experimental diets contained 869, 868 or 870 g/kg LPB, LPP and NPP, respectively, as the sole source of N. The phytate P contents were 0.4, 0.7 and 2.0 g/kg for LPB, LPP and NPP, respectively. Limestone was added to all diets meeting the recommended values, while inorganic P was added only in pea-based diets to provide 65% of the available P recommended by NRC (1998) for 20–50 kg pigs. Titanium dioxide (3 g/kg) was used as an indigestible marker. Daily feed allowance was calculated as 40 g/kg BW at the beginning of each period and was offered in two equal meals at 0800 and 1600 h. Each experimental period lasted for 8 d; d 1–4 for adaptation, d 5–6 for urine and fecal collections, and d 7–8 for ileal digesta collection. The ATTD of DM and GE was not different among diets and was not affected by phytase addition. The ATTD of Ca and P was higher (P<0.05) in LPB than in LPP and NPP diets. Supplementing the LPP and NPP diets with phytase increased (P<0.05) the ATTD of Ca and P. The AID of N and all AA except Met were higher (P<0.05) in LPP and NPP than in LPB, but no difference between LPP and NPP were observed. Phytase supplementation increased (P<0.05) the AID for Arg, Ile, Leu, Phe, Pro, Ser, Tyr, and Val. The SID of AA in LPB, LPP, and NPP were 0.734, 0.895 and 0.895 for Lys, 0.732, 0.757 and 0.744 for Met and 0.755, 0.789 and 0.787 for Thr, respectively. Results indicate that both varieties of field pea had greater AID and SID of AA than LPB. Also, the LPP diet had higher ATTD of Ca and P compared with the NPP diet and phytase supplementation improved digestibility of P, Ca and some AA.
Performance of Nile Tilapia (Oreochromis niloticus) Fed Diets Containing Blood Meal as a Replacement of Fish Meal
(Canadian Center of Science and Education, 2016) Kirimi, James; Musalia, Levi; Magana, Adiel; Munguti, Jonathan
Abstract A 100 days experiment was conducted to determine the effect of feeding blood meal (BM) as a replacement of fish meal (FM), as the main source of animal protein, on growth rate and economic performance of Nile tilapia in fertilized pond. Three isonitrogenous diets (35% crude protein) were formulated using either FM as the main source of animal protein (Diet 1); 50% replacement of FM with blood meal (Diet 2); or 100% replacement of FM with BM (Diet 3). Three hundred Nile tilapia fingerlings (12±3 g) were randomly distributed into three groups of four replicates of 25 fingerlings per cage. The groups were randomly assigned the 3 diets which were fed at 2% of their biomass at 10 am and 4 pm every day. Percentage daily weight gain (DWG), relative growth rate (RGR), specific growth rate (SGR), survival rate and feed utilisation efficiency were measured. Fish fed diet 1 were larger (50.69 g) (P < 0.05) than those fed diet 2 (48.47 g) and 3 (40.37 g). Replacement of FM with 50% and 100% BM reduced the incidence cost (45.55, 37.83 and 31.88, respectively). The profit index was highest with 100% (9.42) replacement of FM, compared to 50% (7.95) and 0% (6.69). Although replacing FM with BM was associated with reduced growth, the economic return was better (P < 0.05). Based on the present results, it was economical to use BM as a major protein source instead of FM in formulating fish feed.
Economic evaluation of progeny-testing and genomic selection schemes for small-sized nucleus dairy cattle breeding programs in developing countries.
(2016) Kariuki, Charles; Brascamp, Pim; Komen, Hans
In developing countries minimal and erratic performance and pedigree recording impede implementation of large-sized breeding programs. Small-sized nucleus programs offer an alternative but rely on their economic performance for their viability. We investigated the economic performance of 2 alternative small-sized dairy nucleus programs [i.e., progeny testing (PT) and genomic selection (GS)] over a 20-yr investment period. The nucleus was made up of 453 male and 360 female animals distributed in 8 non-overlapping age classes. Each year 10 active sires and 100 elite dams were selected. Populations of commercial recorded cows (CRC) of sizes 12,592 and 25,184 were used to produce test daughters in PT or to create a reference population in GS, respectively. Economic performance was defined as gross margins, calculated as discounted revenues minus discounted costs following a single generation of selection. Revenues were calculated as cumulative discounted expressions (CDE, kg) × 0.32 (€/kg of milk) × 100,000 (size commercial population). Genetic superiorities, deterministically simulated using pseudo-BLUP index and CDE, were determined using gene flow. Costs were for one generation of selection. Results show that GS schemes had higher cumulated genetic gain in the commercial cow population and higher gross margins compared with PT schemes. Gross margins were between 3.2- and 5.2-fold higher for GS, depending on size of the CRC population. The increase in gross margin was mostly due to a decreased generation interval and lower running costs in GS schemes. In PT schemes many bulls are culled before selection. We therefore also compared 2 schemes in which semen was stored instead of keeping live bulls. As expected, semen storage resulted in an increase in gross margins in PT schemes, but gross margins remained lower than those of GS schemes. We conclude that implementation of small-sized GS breeding schemes can be economically viable for developing countries.
Performance and phosphorus utilization of broiler chickens fed low phytate barley and pea based diets with graded levels of inorganic phosphorus.
(2017) Kahindi, Roseline Kafedha 1; Thacker, Philip A. 2; Lee, Sang In 3; Kim, In Ho 3; Nyachoti, Charles Martin 1♦
The effects of feeding diets based on soybean meal, low phytate hulless barley (Lphybarley) and low phytate pea (Lphypea) with inorganic phosphorus (iP) reduced by 50 or 100% to broiler chickens on performance, P digestibility and bone characteristics were investigated. Two hundred and ten day-old (Ross 308 strain) broiler chicks (5 birds per cage; 6 cages per diet) were randomly allocated to 7 dietary treatments for a 21-day study. Diets were formulated based on soybean meal-normal phytate hulless barley (SBM-normbarley) with added inorganic P (iP) to meet NRC (1994) P requirements (SBM-normbarley100) or with 50% less iP (SBM-normbarley50), soybean meal-Lphybarley-Lphypea with added iP (Lphybarley-Lphypea100) or iP reduced by 50% (Lphybarley-Lphypea50) or 100% (Lphybarley-Lphypea0), and soybean meal-normbarley normal phytate pea (normpea) with added iP (normbarley-normpea100) or iP reduced by 50% (normbarley-normpea50). Birds fed the Lphybarley-Lphypea0 diet had the lowest (P0.10). Reducing iP content reduced P retention in the SBM-normbarley-based diet but not in the normbarley-normpea-based diet but tibia ash and length were reduced in birds fed both diets (P< 0.05). Reducing dietary iP content linearly increased (P <0.05) retention and linearly decreased (P<0.05) tibia ash and length in the Lphypea-Lphybarley-based diets. In conclusion, feeding a low phytate hulless barley-low phytate pea based diet with iP reduced by 50% supported similar performance as control and increased P retention, suggesting that utilizing a combination of low phytate ingredients can reduce the need for supplemental iP with significant cost and environmental implication.
Nutritive value and Palatability rating of fifteen Selected Indigenous Kenyan Browse Species fed to Small East African Goats.
(Livestock Research for Rural Development 29 (6) 2017, 2017-06) Ondiek, J. O.; Abdulrazak, S. A.; Njoka, E. N.
A palatability study was conducted using fifteen indigenous multipurpose tree leaf forages offered to twenty intact male Small East African Goats, 7 to 8 months and 18kg ± 2.1kg. The CP (gkg-1DM) of the best five species were: M. angolensis (321), A. senegal, (249),Z. mucronata, (200), G. bicolor, (196) and A. brevispica, (187). The NDF and ADF contents ranged from 218-601 for A. hockii and A. amara, and 160-462 for A. hockii and A. abyssinica, respectively. The palatability ranking of the forages was in the order: A. tortilis> M. angolensis> B. aegyptiaca> Z. mucronata> A. coriaria> A. Senegal> A. abyssinica> A. mellifera> A. brevispica> A. elatior> A. amara> G. bicolor> A. nilotica> B. micrantha> A. hockii. M. angolensis and Z. mucronata had OMD of 68.0 and 73.8%, respectively. M. angolensis, Z. mucronata ranked highly on the parameters studied. It is concluded that Maerua angolensis and Zizyphus mucronata being high in nutritive value and palatability, are potential protein supplements to low quality basal diets.
Supplementing Rhodes grass Chloris gayana hay with Maerua angolensis improves weight gain of growing small East African goats
(2018) Ondiek, J. O.; Abdulrazak, S. A.; Njoka, E. N.
To study the performance of Small East African goats fed Rhodes grass(Chloris gayana) hay supplemented with 5 levels of Maerua angolensis (0, 15, 20, 25, 30g DM W0.75) 20 goats were divided into five groups and randomly assigned five treatments in a randomized complete block design based on initial body weight (10.3±1.3kg). The treatment diets were offered twice daily at 08.00 and 14.00 hours with C. gayana and clean water were available ad libitum. Feed intake increased with increasing level ofM. angolensis, whereas, average daily gain, digestibility of DM, CP, NDF and rumen NH3N were the highest on 20g supplementation level. It is concluded that M. angolensis is a potential protein source and can be supplemented at 124 gd-1 (or 20% of metabolic weight, i.e. 20gDM/kgW0.75) for growing Small East African goats.

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