• Asian-Australasian Journal of Animal Sciences
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• v.25 no.7
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• pp.956-961
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• 2012

Eight male cattle of Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava foliage supplementation (Manihot esculenta) on intake, digestibility and N retention. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a $4{\times}4$ double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cattle selected cassava leaves in preference to petioles. Petiole intake decreased from 64 to 48% of offered petioles when the cassava foliage proportion increased from the lowest to the highest level. The cattle consumed all the leaves at the two lower levels of cassava foliage inclusion and 91% at the highest level. Rice straw intake decreased significantly as the level of cassava foliage increased. Intake of DM, OM, NDF, and ADF increased significantly with increasing intake of cassava foliage. Daily DM intake per 100 kg BW increased from 2.7 to 3.2 kg with increasing cassava foliage intake. No effect on CP digestibility was detected when the level of cassava foliage increased. Digestibility of DM, OM, NDF and ADF was significantly higher in the group fed no cassava foliage than in the other groups. N retention increased from 16 to 28 g/d with the first level of cassava foliage inclusion, but levelled out at the two highest levels. N excretion increased in both faeces and urine as a response to higher intake of cassava foliage. Maximum N retention occurred when 40% of total N intake came from cassava foliage (equivalent to 1.3 g CP/kg BW).

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.59-64
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• 2013

Eight male cattle of the Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava (Manihot esculenta) foliage supplementation on mineral metabolism in growing cattle fed rice straw and para grass as basal diet. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a $4{\times}4$ double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cassava foliage intake was lower than the planned levels. DM consumption was significantly affected by cassava foliage supplementation, with the largest intake observed at the two highest levels of cassava foliage supplementation. Rice straw intake showed the opposite pattern, with lower intake at higher cassava foliage supplementation. No refusals occurred for para grass in any of the treatments. Ca, P, Mg, K, S and Mn intake increased significantly with increasing intake of cassava foliage, but Na intake was not affected by treatment. Faecal excretion of Ca, Mg, S and Mn increased significantly with increasing cassava foliage intake. There were no differences between P, K and Na excretion in faeces. There was a significant diet effect on Mg, S and Mn digestibility. Mg and Mn digestibility increased with increasing cassava foliage supplementation, while S digestibility decreased. Ca, P, K and Na digestibility was not affected by diet. There was a significant effect of treatment on P retention, with the highest value observed for supplementation with 1.6 g CP/kg BW cassava foliage. Ca and Mg showed similar trends, with the highest retention again for supplementation with 1.6 g CP/kg BW cassava foliage. There were weak but significant positive correlations between nitrogen retention and the macro minerals Ca, P and Mg. Furthermore, retention of all these minerals was positively correlated. Mineral losses in urine were not affected by dietary treatment with the exception of P excretion, which was affected by treatment. In conclusion, cassava foliage is a good Ca source which compensates for the low Ca content in rice straw and para grass, but P deficiency appears to be exaggerated in cattle with higher cassava intake. The results suggest that under these conditions growing cattle on a high cassava intake would benefit from P and S supplementation.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1424-1432
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• 2007

Two male, rumen fistulated crossbred Brahman-Thai native beef cattle (body weight = $400{\pm}50$ kg), fed on rice straw as a source of roughage, were used as rumen fluid sources. The treatments were $2{\times}3$ factorial arrangements; two roughages (fresh cassava foliage and cassava hay) and three sulfur levels (elemental sulfur) at 0.2 (control), 0.5 and 1% of DM, respectively. The experiment revealed that the rates (c) of gas production, ammonia-nitrogen concentration, true digestibility, total concentration or molar proportions of VFA and microbial biomass were not significantly different between cassava hay and fresh cassava foliage. However, all parameters for cassava hay were higher than for fresh cassava foliage. The supplementation of 0.5% sulfur to fresh cassava foliage resulted in a significant increase in the rate of gas production, true digestibility, total concentration of VFA, microbial biomass, rate of HCN disappearance, thiocyanate appearance and cyanide percentage conversion into thiocyanate. However, there were no effects of sulfur supplementation at 0.2, 0.5 and 1% to cassava hay. The finding suggests the utilization of cassava foliage for rumen microorganisms in terms of fermentation and HCN detoxification could be improved by sulfur supplementation of 0.5% of DM.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.10
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• pp.1366-1376
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• 2009

Effect of sulfur (S) on utilization efficiency of fresh cassava foliage and cassava hay in dairy cows was evaluated using thirty-two $1^{st}-2^{nd}$ lactation Holstein-Friesian crossbred dairy cows. The experimental treatment was a 2${\times}$2 factorial arrangement in a randomized complete block design (RCBD) using two roughages (rice straw+fresh cassava foliage (FCF) and rice straw+cassava hay (CH)) and two elemental sulfur (S) levels (0.15 and 0.4% S of dry matter (DM)), respectively. Four dietary treatments (FCF+0.15, FCF+0.4, CH+0.15 and CH+0.4) were offered ad libitum in the form of a total mixed ration (TMR) with concentrate to roughage (chopped rice straw+chopped cassava foliage) ratio at 60:40. Fresh cassava foliage or cassava hay resulted in similar dry mater intake, rumen ecology parameters, total tract digestibility, blood chemistry, milk production and composition. However, HCN intake, blood and milk thiocyanate concentration were significantly higher (p<0.01) in cows fed fresh cassava foliage with no sign of potential toxicity. Dry matter intake, body weight changes, molar percentage of propionate in rumen, neutral detergent fiber (NDF) digestibility and nitrogen (N) retention of cows tended to be increased while DM digestibility (65.6, 72.7, 68.6 and 72.1% of total DM intake for the respective treatments), rumen bacteria population (1.4, 1.7, 1.6 and $1.7{\times}10^{11}$ cell/ml for respective treatments), fungal zoospore population (0.4, 0.6, 0.4 and $0.5{\times}10^{6}$ cell/ml for respective treatments), urinary allantoin (25.3, 28.0, 26.3 and 27.6 g/d for respective treatments), microbial N yield (136.0, 154.6, 142.8 and 151.3 g N/d for respective treatments) and milk protein content (3.4, 3.5, 3.2 and 3.5% for respective treatments) were significantly (p<0.05) higher in cows fed on supplemented sulfur at 0.4% of DM in comparison with 0.15% S-supplemented diets. Based on these results, it is concluded that cassava foliage could be used as a portion of roughage for dairy cows and supplementation of S would be nutritionally beneficial.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.12
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• pp.1691-1700
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• 2012

The experiment studied the effect of harvesting frequencies and varieties on yield, chemical composition and hydrogen cyanide content in cassava foliage. Foliage from three cassava varieties, K94 (very bitter), K98-7 (medium bitter) and a local (sweet), were harvested in three different cutting cycles, at 3, 6 and 9 months; 6 and 9 months and 9 months after planting, in a 2-yr experiment carried out in Hanoi, Vietnam. Increasing the harvesting frequency increased dry matter (DM) and crude protein (CP) production in cassava foliage. The K94 variety produced higher foliage yields than the other two varieties. Dry matter, neutral detergent fibre (NDF), acid detergent fibre (ADF) and total tannin content increased with months to the first harvest, whereas CP content decreased. Hydrogen cyanide (HCN) content was lower at the first harvest than at later harvests for all cutting cycles. At subsequent harvests the content of total tannins tended to decline, while HCN content increased (p<0.05). Chemical composition differed somewhat across varieties except for total tannins and ash. Dry matter, NDF, ADF and total tannins were higher in fully matured leaves, while CP and HCN were lower in developing leaves.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.1029-1035
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• 2005

A 3${\times}$4 factorial field experiment with a complete randomised split-plot design with four replicates was conducted from June 2002 to March 2003 at the experimental farm of the Nong Lam University, Ho Chi Minh City, Vietnam, to determine effects of different harvesting heights (10, 30 and 50 cm above the ground) and cutting intervals (45, 60, 90 and 285 days) on yield of foliage and tubers, and chemical composition of the foliage. Cassava of the variety KM 94 grown in plots of 5 m${\times}$10 m at a planting distance of 30 cm${\times}$50 cm was hand-harvested according to respective treatments, starting 105 days after planting. Foliage from the control treatment (285 days) and all tubers were only harvested at the final harvest 285 days after planting. Dry matter and crude protein foliage yields increased in all treatments compared to the control. Mean foliage dry matter (DM) and crude protein (CP) yields were 4.57, 3.53, 2.49, and 0.64 tonnes DM $ha^{-1}$ and 939, 684, 495 and 123 kg CP $ha^{-1}$ with 45, 60, 90 and 285 day cutting intervals, respectively. At harvesting heights of 10, 30 and 50 cm the DM yields were 4.27, 3.67 and 2.65 tonnes $ha^{-1}$ and the CP yields were 810, 745 and 564 kg $ha^{-1}$, respectively. The leaf DM proportion was high, ranging from 47 to 65%. The proportion of leaf and petiole increased and the stem decreased with increasing harvesting heights and decreasing cutting intervals. Crude protein content in cassava foliage ranged from 17.7 to 22.6% and was affected by harvesting height and cutting interval. The ADF and NDF contents of foliage varied between 22.6 and 30.2%, and 34.2 and 41.2% of DM, respectively. The fresh tuber yield in the control treatment was 34.5 tonnes $ha^{-1}$. Cutting interval and harvesting height had significant negative effects on tuber yield. The most extreme effect was for the frequent foliage harvesting at 10 cm harvesting height, which reduced the tuber yield by 72%, while the 90 day cutting intervals and 50 cm harvesting height only reduced the yield by 7%. The mean fresh tuber yield decreased by 56, 45 and 27% in total when the foliage was harvested at 45, 60 and 90 day cutting intervals, respectively. It is concluded that the clear effects on quantity and quality of foliage and the effect on tuber yield allow alternative foliage harvesting principles depending on the need of fodder for animals, value of tubers and harvesting cost. An initial foliage harvest 105 days after planting and later harvests with 90 days intervals at 50 cm harvesting height increased the foliage DM and CP yield threefold, but showed only marginal negative effect on tuber yield.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.463-472
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• 2003

Cassava (Manihot esculenta, Crantz), an annual tropical tuber crop, was nutritionally evaluated as a foliage for ruminants, especially dairy cattle. Cultivation of cassava biomass to produce hay is based on a first harvest of the foliage at three months after planting, followed every two months thereafter until one year. Inter-cropping of leguminous fodder as food-feed between rows of cassava, such as Leucaena leucocephala or cowpea (Vigna unculata), enriches soil fertility and provides additional fodder. Cassava hay contained 20 to 25% crude protein in the dry matter with good profile of amino acids. Feeding trials with cattle revealed high levels of DM intake (3.2% of BW) and high DM digestibility (71%). The hay contains tannin-protein complexes which could act as rumen by - pass protein for digestion in the small intestine. As cassava hay contains condensed tannins, it could have subsequent impact on changing rumen ecology particularly changing rumen microbes population. Therefore, supplementation with cassava hay at 1-2 kg/hd/d to dairy cattle could markedly reduce concentrate requirements, and increase milk yield and composition. Moreover, cassava hay supplementation in dairy cattle could increase milk thiocyanate which could possibly enhance milk quality and milk storage, especially in small holder-dairy farming. Condensed tannins contained in cassava hay have also been shown to potentially reduce gastrointestinal nematodes in ruminants and therefore could act as an anthelmintic agent. Cassava hay is therefore an excellent multi-nutrient source for animals, especially for dairy cattle during the long dry season, and has the potential to increase the productivity and profitability of sustainable livestock production systems in the tropics.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.66-74
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• 2008

Two experiments were conducted to assess the effect of replacing a conventional concentrate with mixed cassava (Manihot esculenta) foliage and legume (Phaseolus calcaratus) foliage. In Exp. 1, three rumen fistulated crossbred cows were used for in sacco rumen degradability studies. In vitro gas production was also studied. In Exp. 2, 11 crossbred F2 heifers (Red Sindhi$\times$Holstein Friesian), with initial live weight of $129{\pm}6kg$ and aged six months, were allocated in a Completely Randomized Design (CRD) to evaluate a mixture (ratio 3:1) of cassava and legume foliage (CA-LE feed) as a protein source compared to a traditional concentrate feed (Control) in diets based on fresh elephant grass (Pennisetum purpureum) and urea treated rice straw ad libitum. The Control feed was replaced by the CA-LE feed at levels of 0% (Control), 40% (CA-LE40), and 60% (CA-LE60) based on dry matter (DM). The in sacco degradation of CA-LE feed was higher than Control feed (p<0.05). After 48 h incubation the degradation of CA-LE feed and Control feed was 73% vs. 58% of DM and 83% vs. 65% of CP, respectively. The gas production of CA-LE feed was also significantly higher than of Control feed during the first 12 h of incubation. The results of the performance study (Exp. 2) showed that the level of CA-LE feed in the concentrate had no effect on total dry matter intake (p>0.05), but live weight gains (LWG) in CA-LE40 and CA-LE60 were significantly higher (551 and 609 g/d, respectively) than in the Control group (281 g/d). The intake of CP was higher (p<0.05) for the treatments CA-LE40 and CA-LE60 (556 and 590 g/d, respectively) compared to that of Control (458 g/d), while there was no significant difference in ME intake. The feed conversion ratio was 16.8, 9.0 and 7.9 kg DM/kg LWG in Control, CA-LE40 and CA-LE60, respectively. The feed cost of CA-LE40 and CA-LE60 corresponded to 43% and 35%, respectively, of the feed cost of Control feed. The best results were found when CA-LE feed replaced 60% of DM in Control feed and considerably decreased feed cost. It is concluded that feeding cassava foliage in combination with Phaseolus calcaratus legume as a protein supplement could be a potentially valuable strategy which leads to reduced feed costs and a more sustainable system in smallholder dairy production in Vietnam.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1763-1769
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• 2003

Two experiments were conducted to examine the production and quality of cassava hay and its utilization in diets for dairy cows. In experiment I, a $2{\times}2$ Factorial arrangement in a randomized complete block design with 4 replications was carried out to determine the effects of different initial (IC) and subsequent cutting (SC) on yield and composition of cassava plant. The results revealed that cassava could produce from 4 to 7 tonne of DM and 1.2 to 1.6 tonne of CP for the first six months after planting. CP content in cassava plant ranged from 20.8 to 28.5% and was affected by different SC regimes. Condensed tannin in cassava foliage ranged from 4.9 to 5.5%. Initial cutting at 2 months with subsequent cutting at 2 month intervals was the optimal to obtain high dry matter and protein yield. In the second experiment, five crossbred Holstein-Friesian cows in mid lactation with an initial live-weight of 505${\pm}6.1kg$ and average milk yield of 10.78${\pm}1.2kg/d$ were randomly assigned in a $5{\times}5$ Latin square design to study the effects of 2 levels of CH (1 and 2 kg/hd/d) and concentrate (1 to 2 kg of milk and 1 to 3 kg of milk) on milk yield and milk composition. The results showed that cassava hay increased rumen $NH_3-N$ and milk urea nitrogen (MUN) (p<0.05). Cassava hay tended to increase milk production and 4% FCM. Milk protein increased in cows fed cassava hay (p<0.05). Moreover, cassava hay could reduce concentrate levels in dairy rations thus resulting in increased economic returns. Cassava hay can be a good source of forage to reduce concentrate supplementation and improve milk quality.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.828-833
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• 2002

Thirty mature pregnant ewes of the Phan Rang breed with an initial live weight of 30 to 45 kg were used to compare the effects of three different diets in late pregnancy on ewe and lamb performance. All diets contained 20% of whole sugar cane, 16% rice bran, 26% cassava root and 6% molasses urea block. The remaining 32% of dry matter consisted of Jackfruit (JF diet), 16% each of Jackfruit and Cassava foliage (JF+CS diet) or Jackfruit and Flemingia foliage (JF+FM diet). The diets were fed at 3.5% of actual BW of the individual animal. The foliages were offered at 120% of the amount decided in the diets of the requirements. The JF+CS diet resulted in significantly higher feed intake than the JF diet, and also a higher feed intake than the JF+FM diet, but this difference was not significant. The ewe weight changes during the last 8 weeks of pregnancy, or from start to 24 h after lambing, were significantly different. The highest weight gain was obtained from the ewes fed the JF+CS diet. Diets had no effect on weight changes of ewes during 3 weeks after lambing but a significant effect on the litter birth weight, with the JF+CS diet giving the highest litter birth weight. There was, however, no effect on the litter weight at 21 days or litter growth rate from birth to 21 days due to the experimental diets.