Cassava Diet Research Articles

The effects of three protein sources on the growth and feed utilization of cattle fed cassava

SummaryThe nutritive value of diets predominantly of dried cassava (Manihot esculenta Crantz.) tubers supplemented with protein concentrates, and roughage were measured in three experiments using steers.In Expt 1 the digestibility of diets of dried, chipped cassava tubers and tops (80:20) or rolled sorghum grain and cotton seed hulls (80:20), supplemented with 4 or 8% groundnut meal and urea, was determined. The apparent digestibility coefficients of organic matter (OM) of the cassava diets with 4 or 8 % groundnut meal (0·77 and 0·80, respectively) were significantly (P < 0·01) higher than grain diets with 4 or 8% groundnut meal (both 0·74). The digestibility of starch in the cassava diets was significantly (P < 0·01) higher than in the grain diets (1·00, 0·99, 0·94 and 0·93, respectively). There were no significant differences in the digestibility of the N component (0·62 and 0·61 v. 0·58 and 0·59, respectively). The N retained (g/day) was lower (P > 0·05) with cassava (7·8 and 6·8 v. 11·1 and 10·5, respectively) and was utilized (g/100 g apparently absorbed N) less efficiently (P > 0·05) (18 and IS v.28 and 27, respectively).The high apparent digestibility of the cassava diet suggests that cassava could replace cereal grain in intensive finishing diets. The N retention data suggest that groundnut meal is no better than urea as a N source.In Expt 2, 15 steers with a mean initial weight of 173 kg were individually fed pelleted diets of sorghum grain, cassava plus urea or cassava plus meat and bone meal (90 concentrate: 10 roughage). The cattle fed the grain diet ate significantly (P < 0·01) more OM (4·3 v. 3·4 kg/day), grew faster (P < 0·01) (1·21 v. 0·85 kg/day) and slightly more efficiently (P > 0·05) (3·6 v. 3·8 kg/kg) than cattle fed cassava with urea. Cattle fed cassava with meat and bone meal were intermediate between the two treatments for intake and daily gain (3·7 and 1·06 kg/day, respectively) but had the best feed conversion (3·5 kg/kg). The acetic/propionic acid ratio was similar on all three diets (1·2, 1·6 and 1·4:1, respectively), but the ratio of propionic/butyric was significantly (P < 0·01) different (5·8, 2·7 and 2·7:1, respectively).In Expt 3, 15 other steers with mean initial weight of 195 kg were individually fed pelleted cassava diets with 0, 5 or 10% fishmeal (82 cassava: 18 roughage). The intake of OM (4·2, 4·5 and 4·7 kg/day, respectively), daily live-weight gain (0·98, 1·27 and 1·32 kg/day, respectively) and feed conversion (4·3, 3·7 and 3·7 kg/kg, respectively) were all better in cattle fed cassava with fishmeal. The proportions of volatile fatty acids in the rumen fluid were similar to that recorded in cassava fed cattle in the earlier trial.It is concluded that cattle fed high energy diets based on dried cassava tubers can perform well. Although feed intake and daily gain of cattle fed cassava may be lower than for cattle fed grain diets, the conversion of food to live-weight gain should be similar or better.

Vitamin B nutrition in the Nigerian tropical ataxic neuropathy.

Assessment of nutritional status of vitamin B components by plasma or blood levels indicated riboflavin deficiency and possibly thiamine deficiency in Nigerian patients who suffered from tropical ataxic neuropathy and neurologically normal Nigerians who subsisted on predominant cassava diet. Serum levels of folate, niacin, pyridoxine and panthothenic acid were normal. Vitamin deficiencies probably are minor factors, if any, in the pathogenesis of tropical ataxic neuropathy in Nigerians.

The teratogenic effects of dietary Cassava on the pregnant albino rat: a preliminary report.

Cassava is a tuberous root of a shrublike plant cultivated in tropical rain forests as a staple food in South Eastern Nigeria. Reports are on record showing correlation between cassava intake and occurrence of various types of neuropathies (Money, '59; Monekosso and Wilson, '66; Osuntokun et al., '68,'69). About 0.1-2 mg of cyanide/100 gm is released from Cassava by action of hydrolase (Paula and Rangel, '46). It has been suspected by several local clinicians as a cause of congenital anomalies if consumed in excess during pregnancy. However, it remains a controversial problem and precise scientific data is lacking. This study was conducted on albino rats by giving them milled cassava powder as 50% and 80% of their diet during the first 5 days of pregnancy. Fetuses collected on day 20 from the group receiving cassava as 80% of the diet showed a low incidence of limb defects, open eye, microcephaly, and growth retardation in the rat. Interpretation of this data for the human should be made with caution.

Performance and pathophysiological changes in pregnant pigs fed cassava diets containing different levels of cyanide

Eighteen pregnant Yorkshire gilts were allotted to three equal groups and fed fresh cassava diets containing 0 mg, 250 mg and 500 mg cyanide per kg of fresh cassava offered. Dietary cyanide level had no significant effect on either the number or the weights of 110-day-old fetuses. Serum thiocyanate concentration was slightly but not significantly increased in the 500 ppm cyanide group and serum protein bound iodine decreased during geslation in all groups. Fetal serum thiocyanate concentration was significantly (P

Effect of fermentation and palm oil on the performance of broilers receiving cassava diets in the tropics

ABSTRACTThe effect of fermentation on cassava meal diets supplemented with 0, 2, 4 and 6% levels of palm oil on the performance, carcass characteristics and economic value of broiler chickens was studied. During the growing phase, fermentation had no influence on growth rate, but resulted in reduced mortality and improved efficiency of feed utilization in the chickens. However, there were greater intakes of fermented cassava meal diets, higher efficiency of feed utilization, better growth rate and reduced mortality during the finishing phase. Abdominal fat was lower during both phases in chickens given the fermented cassava meal diets than those given the cassava meal diets. There was evidence of economic benefits in reduced feed cost, increased gross revenue and higher revenue less feed cost values in fermented cassava meal than in cassava meal diets. There were non-significant reductions in feed intake, mortality rate, daily rate of gain, final body weight and carcass quality, but significant economic benefits during both growing and finishing phases as the level of supplementary palm oil increased in the diets. The results suggest that while about 2% palm oil might be required in fermented cassava meal diets, 2 to 4% would be needed in cassava meal diets by broiler chickens for comparable performance.

Cyanide content of gari

500 random samples of gari (a cassava by-product) being hawked for sale in Ibadan markets, in Nigeria, were assayed for hydrocyanic acid (HCN) content. Most of the samples contained detectable amounts of HCN, ranging between 0.8 and 38 mg/kg, and only a very small proportion (0.4%) contained no cyanide. The limit of HCN detection was 0.1 ppm. There was no significant difference ( P < 0.01) between the mean total cyanide (glycoside-bound plus non-glycosidic) and free cyanide (non-glycosidic) contents, 8.0 ± 6.9 mg HCN/kg and 7.2 ± 5.8 mg HCN/kg, respectively; indicating that an overwhelming proportion of the residual cyanide content of commercial gari could be present in the “free” form. The toxicity implications of free cyanide in cassava diets is briefly discussed.

Raw and steam-pelleted cassava, sweet potato and yam cayenensis as starch sources for ruminant and chicken diets

Three tropical tubers, raw or processed by steam-pelleting, were studied in the rumen in vitro or in the chicken in vivo in order to determine the effects of the nature and of the treatment of the tubers on urea utilization by rumen microflora, starch breakdown in the crop and the performance of growing chickens. Starch of cassava ( Manihot utilissima) and of sweet potato ( Ipomea batata) is characterised by an X-ray diffraction pattern of the A-type and is therefore similar to starch of cereals. In vitro these starches were well broken down in the presence of α-amylase from B. subtilis, and were good sources of energy for rumen microbial growth; in vivo they were completely digested by growing chickens. Compared to cassava, the fermentation of sweet potato in rumen and crop led to increased acidity. The cassava diet gave a better nitrogen retention and growth performance associated with higher food intake. In contrast, starch of yam ( Dioscorea cayenensis) which is characterized by an X-ray diffraction pattern of the B-type, and by large granules like potato starch, was less susceptible to α-amylase and promoted lower microbial proteosynthesis in vitro. Starch from a yam diet was more slowly degraded in the crop and its overall digestibility was only 83%. Yam reduced feed intake and gave lower nitrogen retention and lower food conversion ratio and consequently poor growth. The steam-pelleting treatment increased starch availability and permitted better urea utilization by rumen microflora. It improved N retention and feed efficiency of chicken diets, although not significantly. The greatest effect of the treatment was observed with yam. In conclusion, the digestibility of a given starch seems to be related to its structure, characterized by the type of X-ray diffraction pattern, which could be a help in tuber selection for animal nutrition. Simple processing such as steam-pelleting may improve the nutritive value of a tuber, especially when its starch has a B-type crystallinity.

Influence of cassava diets on placental thiocyanate transfer, tissue rhodanese activity and performance of rats during gestation

AbstractTwo nineteen day rat gestation/metabolic studies were carried out with thirty female rats to investigate the influence of fresh and dried cassava containing 173 parts/106 and 92 parts/106 HCN respectively on placental thiocyanate transfer, metabolic changes in maternal and foetal tissues and their gestational performance. The cassava diets caused marked changes in the weight gain and thiocyanate concentration of the urine and serum of the gestating rats. Amniotic fluid thiocyanate was significantly increased by the fresh cassava diets (P&lt;0.01), but foetal thiocyanate was not significantly different between treatments (P&gt;0.05). Rhodanese activity and fresh weights of maternal and foetal tissues were also not significantly affected by the cassava diets (P&gt;0.05).

The Metabolizable Energy of Some Tropical Tuber Meals for Chicks

Two consective experiments were conducted with 360 White Leghorn cockerels, approximately two weeks old, to compare the metabolizable energy (M.E.) and metabolizable energy corrected to nitrogen equilibrium (M.E.n) for dehydrated cassava, cocoyam, yam, plantain and sweet potato meals. These were tested at 40 and 25% levels of substitution in the first and second experiment respectively. No consistent differences were observed for the M.E. and M.E.n values due to level of substitution. The range of M.E. and M.E.n for sweet potato in both experiments (3.94–4.11 and 3.73–3.89 kcal./g.) were non-significantly higher than those for cassava (3.78–3.88 and 3.66–3.78 kcal./g.), but both these sources had significantly superior M.E. and M.E.n compared with those for yam (3.24–3.36 and 3.19–3.28 kcal./g.) and plantain (3.16–3.29 and 3.04–3.22 kcal./g.). The corresponding values of 2.73–2.88 and 2.72–2.82 kcal./g. for cocoyam were significantly (P < 0.05) lower than for all the other tubers. The percentage gross energy as M.E. for cocoyam, yam and cassava were 65.31–68.90, 75.70–78.51 and 69.60–72.42, respectively. These were significantly (P < 0.05) lower than the fairly similar values of 86.90–89.20 and 87.17–90.93 for cassava and sweet potato, respectively. Rate and efficiency of gain was best for sweet potato at both the 25 and 40% levels of substitution, cassava and plantain showing significantly lower rate and efficiency of gain in comparison. Yam in turn gave rates and efficiency of gain significantly lower than for the later two tubers while cocoyam had significantly (P < 0.05) the lowest rate and efficiency of gain.The results suggest that sweet potato and cassava are superior energy sources compared to the others, although the growth promoting ability of the cassava diet tended to be reduced by the possible presence of some residual growth inhibitory factor in the dehydrated meal.

Cassava diet and cyanide metabolism in Wistar rats.

1. In the aetiopathogenesis, in Nigerians, of a degenerative neuropathy known as tropical ataxic neuropathy, chronic cyanide intoxication is believed to be the most important factor. The source of the cyanide is cassava (Manihot) and in Nigerian patients, plasma concentration of thiocyanate, a major detoxication product of cyanide, is high.2. Since there is considerable doubt as to whether cyanide is readily released from cassava diet after ingestion, rats were fed on 80 and 100% purupuru (a cassava derivative) diets for periods varying between 6 and 18 months and their plasma thiocyanate levels were studied. Control rats were fed on a normal diet for the same periods.3. Rats fed on the 100% purupuru diet were malnourished. Rats fed on the 80 % purupuru diet appeared normal, although their mean weight was less than the mean weight of rats fed on the normal diet.4. Plasma thiocyanate was significantly higher in rats fed the purupuru diets than in the rats fed on the normal rat diet.5. The concentration of thiosulphate Sulphurtransferase, the enzyme that catalyses the conversion of cyanide into thiocyanate was the same in rats fed on the purupuru diets as in the control rats.6. The results suggest that raised plasma thiocyanate levels found in Nigerian patients with ataxic neuropathy, as in rats fed cassava diet, is the result of detoxication of cyanide, as the concentration of thiocyanate in cassava and most food products eaten by Nigerians is low.

The protein quality of cassava leaves.

1. A chemical and biological evaluation of the protein content of some leaves and leaf extracts from the eastern region of Nigeria (Biafra) has been made: most were from cassava (Munihot utilissima).2. The protein content of the leaves was from 3 0 to 40% (expressed as percentage of leaf dry matter). The concentrations of essential amino acids were adequate, except for methionine. The biological criteria, true digestibility (TD) and biological value (BV), showed that the digestibility was from 70 to 80%, whereas BV varied from 44 to 57%, depending on the methionine content.3. Adding methionine to a diet of cassava leaves raised BV from 49 for the leaves alone to 80 for the mixture. This relationship clearly shows that cassava leaves contain too little available methionine. An investigation into the true availability of the amino acids showed that this is somewhat variable, and only 60% of the methionine is available.4. The BV of cassava leaves combined with Norwegian dried cod showed a mutual supplementation effect.

Nutritive Value of Various Energy Sources for Poultry Feed

Biological assay technique was applied for the determination of available energy of cassava meal, which was imported from Thailand for the first trial. Standard curve was obtained with the growth rate of chicks fed standard diets of various energy levels. Corn starch and yellow corn in the standard diet was replaced with cassava meal and levels of soybean oil and fish weal were adjusted to set the dietary energy and protein levels. With the growth rate of chicks on diet containing cassava meal, available energy of cassava meal was calculated with electronic computer. The available energy was shown as percentage of total digestible nutrients as in the previous 3 papers2, 3, 11).In Expt. 411, it was shown that cassava meal fed at the level of 32.3% had growth retarding effect to day-old White Leghorn chicks, although no chick died during the experimental period of 4 weeks. In Expt. 503, cassava meal was soaked in water overnight or autoclaved at 120°C. for 1 hour. These treatments were quite effective to improve the growth rate of chicks. Diets containing 10 and 20% raw cassava meal were also fed in this experiment and it was revealed that chicks on 10% cassava diet grew almost satisfactorily, but the growth rate of chicks on 20% cassava diet was much slower than expected. To confirm the observation, diets containing 10 and 15% raw cassava meal was fed to 4-week-old chicks in Expt. 505. The growth rate of chicks on 10% cassava diet was normal but that on 15% cassava diet was not.It was revealed in these experiments that cassava meal had some growth inhibiting factor which will be removed by heat-treatment or water-soaking. The growth-retarding effect was not detected when cassava meal was fed at 10% level. Prussic acid in cassava mael was discussed as the most possible growth-retarding factor. Available energy of cassava meal, when fed at 10% level or autoclaved or soaked in water was estimated. 70% in average. It is ecommended to use cassava meal at the level of less than 10% in poultry feed.P.S. after the preparation of the manuscript, the authors have received the reprints of papers of Dr. Vogt et al, 20, 21, 22) in which it was reported that the growth rate of broiler chicks on the diet containing 10% of cassava meal was normal. The content of prussic acid in their sample22) was much less than 36ppm in the sample tested in this paper.

Nutritive value of cereal and cassava diets for growing and fattening pigs in Nigeria.

Nutritive value of cereal and cassava diets for growing and fattening pigs in Nigeria.

Changes in the adrenal and pitultary gland in experimental malnutrition.

SUMMARY 1. An investigation has been made of the effects of malnutrition produced by a diet of cassava on the adrenal cortex and hypothalamo-neurohypophysial system of rodents. 2. The renal response to isotonic saline was impaired in the malnourished animals. A reduction in adrenal ascorbic acid and in neurohypophysial pressor content also occurred. 3. In response to an intravenous isotonic saline load, adrenalectomized animals were unable to excrete as great a volume of urine as sham-operated controls, but no differences were detected in urinary sodium output. 4. In the malnourished animals, histochemical observation revealed a fall in adrenal alkaline phosphatase activity and impaired synthesis and secretion of neurosecretory material in the hypothalamo-neurohypophysial system. 5. From the evidence presented it is likely that the reduced renal response to isotonic saline in the malnourished animals reflects a disturbance in the adrenal cortex rather than increased secretion of antidiuretic hormone.

Studies in water metabolism in clinical and experimental malnutrition

1. (1) Children with kwashiorkor were found to have an impaired renal response to water and an increased virtual deuterium space. Following high protein therapy, an increased renal response to water occurred in all but one patient, and the virtual deuterium space decreased in every case. 2. (2) Adult male rats kept on a diet of cassava for 15 weeks, lost weight, had an impaired renal response to water and an increased virtual deuterium space.