Potential of dried cassava pulp as an alternative energy source for laying hens

Two experiments were conducted to evaluate the potential use of dried cassava pulp (DCP) with reference to productive performance, nutrient digestibility, egg quality, egg yolk cholesterol, cecal microbial populations, and volatile fatty acids production in laying hens. In experiment 1, a total of 48 laying hens (Isa Brown) were placed in individual cages and assigned randomly to one of 6 dietary treatment groups consisting of a control and 5, 10, 15, 20, and 25% DCP for 10 d. Feeding laying hens with diets containing up to 20% DCP did not affect the dry matter (DM) and organic matter (OM) digestibility and nitrogen (N) retention (P > 0.05). In experiment 2, a total of 288 laying hens (Isa Brown) were randomly distributed to 6 dietary groups (one control and 5 DCP: 5, 10, 15, 20, and 25%) for 12 wk. The results show that diets containing up to 20% DCP had no significant effects on productive performance or egg quality (P > 0.05). The inclusion of DCP at levels of 20 to 25% showed a positive effect on decreased egg yolk cholesterol (P < 0.05). In addition, DCP also increased the cecal Lactobacillus and Bifidobacterium populations, acetic acid, and propionic acid production. In conclusion, DCP can be used as part of the energy source in laying hen diets at up to 20% inclusion, without showing negative effects on productive performance, nutrient digestibility, and egg quality. Feeding DCP can potentially modulate egg yolk cholesterol and cecal microbial populations and alter volatile fatty acids production.     

The use of methane-utilising bacteria as a source of protein for young chicks

Two strains of continuously‐grown, methane‐utilising bacteria were found to contain 8.96 and 9.95% N and a favourable pattern of essential and non‐essential amino acids, the concentrations of which were generally higher than those previously observed in batch grown organisms (D'Mello, 1972).

One of these strains has been evaluated as a protein source for young chicks. Four diets were employed : the first was a control maize‐soybean diet supplemented with methionine; the second was similar to the control diet except that 10% bacterial protein was included largely at the expense of soybean; the third, a low‐protein diet, was identical to the second in all respects except that the bacterial protein source was substituted by an equivalent weight of ground maize ; the fourth consisted mainly of maize and dried whole egg served as an additional control diet.

There were no significant differences in growth, efficiency of food conversion or nitrogen retention between the control group and the group receiving the bacterial protein. Furthermore, chicks in these two groups performed significantly better than either those fed on the low‐protein diet or those fed on the whole egg diet.

Amino acid and uric acid concentrations in plasma were similar in the control and bacterial protein groups although levels tended to be lower in chicks consuming the low‐protein diet. Activities of glutamic‐oxalacetic and glutamic‐pyruvic transaminases in plasma were similar in all dietary groups.

These results suggest that the strain of methane‐oxidising bacteria used in the present study is potentially a useful source of protein for non‐ruminant animals.     

Cassava chip(Manihot esculenta Crantz) as an energy source for ruminant feeding

Cassava(Manihot esculenta Crantz) is widely grown in sub-tropical and tropical areas, producing roots as an energy source while the top biomass including leaves and immature stems can be sun-dried and used as cassava hay. Cassava roots can be processed as dried chip or pellet. It is rich in soluble carbohydrate(75 to 85%) but low in crude protein(2 to 3%). Its energy value is comparable to corn meal but has a relatively higher rate of rumen degradation. Higher levels of non-protein nitrogen especially urea(1 to 4%) can be successfully incorporated in concentrates containing cassava chip as an energy source. Cassava chip can also be processed with urea and other ingredients(tallow, sulfur, raw banana meal, cassava hay, and soybean meal) to make products such as cassarea, cassa-ban, and cassaya. Various studies have been conducted in ruminants using cassava chip to replace corn meal in the concentrate mixtures and have revealed satisfactory results in rumen fermentation efficiency and the subsequent production of meat and milk. In addition, it was advantageous when used in combination with rice bran in the concentrate supplement. Practical home-made-concentrate using cassava chip can be easily prepared for use on farms. A recent development has involved enriching protein in cassava chips, yielding yeast fermented cassava chip protein(YEFECAP) of up to 47.5% crude protein, which can be used to replace soybean meal.It is therefore, recommended to use cassava chip as an alternative source of energy to corn meal when the price is economical and it is locally available.     

Lysine requirement of broiler chicks as affected by protein source and method of statistical evaluation 1

1. An experiment was designed to test if the lysine requirement, expressed as g lysine/kg CP, was the same for several protein sources.

2. Groundnut meal, groundnut meal adjusted with indispensable amino acids or sesame meal supplied the dietary CP at 180 g/kg diet. Increments of lysine (1.5 g/kg diet) were added to each of these diets.

3. The gain, food intake and food efficiency responses of broiler chicks were analysed using a quadratic equation and a two‐slope method. An estimate of lysine requirements was also obtained from a survey of college students.

4. The different methods produced widely different estimates of lysine requirement.

5. The average lysine requirement was estimated at 50.1 g lysine/kg CP for groundnut meal, 61.7 for adjusted groundnut meal and 54.9 for sesame meal.

6. Reasons for the effect of statistical analysis and protein source on lysine requirement are discussed.     

Processing and feeding value of mango seed kernel for starting chicks

1. De‐oiled mango seed kernel meal (MSK) was found to contain tannins, cyanogenetic glucosides and traces of alkaloids and gums. Treating with 0#lb3 m HCl followed by Ca(OH)₂ suspension removed all of the tannins and much of the cyanogenetic glucosides and gums.

2. Substitution of 141 g MSK/kg diet for maize in a practical diet did not affect performance of chicks, whereas adverse effects occurred with 282 g or more/kg.

3. Processing of MSK improved performance but it was still not equivalent to that achieved with maize.

4. Increasing the protein content of the diet containing processed MSK from 207 to 226 g/kg did not improve performance and replacing ground nut meal with soyabean meal depressed performance.     

Apparent metabolisable energy values of fats for broiler chicks

Seven fats were included at 30, 60 and 90 g/kg (experiment 1) and at 20, 40, 60 g/kg (experiment 2) in a semi-synthetic fat-free diet and in a practical diet respectively. Apparent metabolisable energy (AME) was evaluated with 6 replicate cages each with three Ross 1 cockerel chicks 8 d old. Diets were fed for 11 d and a total collection of excreta undertaken for the last four. There was no significant departure from linearity in the response of dietary AME to added fat, indicating no interactions between basal diet and added fat. In experiment 3 one fat was evaluated at 10 rates of inclusion (10 g/kg to 100 g/kg in 10 g increments) in both a semi-synthetic fat-free basal and a practical basal diet. A significant departure from linearity in the response of dietary AME to added fat was detected but there was no significant fat X basal diet interaction. In experiment 4 twelve commercially available fat blends were each evaluated at 10 rates of inclusion (15 g/kg to 150 g/kg in 15 g increments) in a practical basal diet. Significant departures from linearity in the responses of dietary AME to added fat were observed with some of the fats. It was concluded that the AME of fats mat be determined from multi-level assays by interpolating the quadratic relationships derived.     

不断寻求可持续性能源资源

农业的责任是要引领绿色明天．饲料和食品业作为农业的生产商和供应商．也要担当创造可持续性环境的责任。     

Nutrient dependence of energy preservation requirements in rats. 1. Dependence of energy requirements for preservation in fully-grown rats on the type of nutrient offered as the sole energy source

In two experiments with fully-grown albino rats (Wistar strain) the energetic utilization of glucose, sunflower oil and casein in the maintenance metabolism was determined under thermoneutral conditions of keeping the animals. The relative requirement of metabolizable energy for maintenance was, with either glucose, sunflower oil or casein being the sole energy source of the feed, in experiment 1 100:105:133 and in experiment 2 100:102:135. The absolute values of the maintenance requirement of metabolizable energy were in experiment 1 347 +/- 26, 364 +/- 61 and 460 +/- 33 resp., and in experiment 2 330 +/- 11, 337 +/- 21 and 446 +/- 27 kJ/kg LW 0.75 resp. The results are discussed in connection with the efficiency of ATP synthesis (metabolizable energy/mol ATP gain) in the oxidative decomposition of nutrients.     

Effect of lincomycin as a growth promoter for broiler chicks

1. The effects of adding lincomycin to either the food (2.2 mg/kg) or drinking water (equivalent or 0.5 equivalent amount) of male broiler chicks were examined. 2. There were four treatments: control (no lincomycin), diet containing 2.2 mg lincomycin/kg, control diet plus drinking water containing lincomycin at concentrations calculated to provide an intake equivalent to treatment 2, and treatment 14 with lincomycin concentration reduced by half. 3. There was no significant effect of any treatment upon mortality, efficiency of food utilisation at 42 d of age, final body weights or monetary indices. 4. Analyses of breast, thigh and liver tissues, using a method with a sensitivity of 1.0 mg/kg, failed to reveal any evidence of lincomycin residues. 5. It is concluded that the use of lincomycin at 2.2 mg/kg may not be effective in improving either the biological or economic performance of the broiler chicken.     

Rice bran lysolecithin as a source of energy in broiler chicken diet

1. Rice bran lysolecithin (RBL) was evaluated in broiler chicken diets. In the first experiment, RBL was included in diet at 0, 0·5, 2, 8 and 32?g/kg and fed to 250 broiler chickens from 0 to 42?d of age. In the second experiment, RBL was fed at 0, 25 and 50?g/kg diet to 405?day-old broiler chickens until 21?d of age, while during the finisher phase (22–35?d of age) chickens receiving each concentration of RBL were given all three concentrations of RBL in a 3?×?3 factorial manner. The diets were isocaloric.

2. Body weight, food consumption and food conversion efficiency were unaffected by feeding RBL, while the weight of pancreas increased at ≥2?g/kg of RBL in diet (experiment 1). In experiment 2, body weight was greater in the chickens receiving RBL at either 25 or 50?g/kg (21?d) and 50?g/kg (35?d of age). At 21?d of age, food consumption was greater at 25 or 50?g RBL/kg diet, while food conversion efficiency improved with 50?g RBL/kg diet.

3. Fat digestibility increased with RBL at 32?g/kg (experiment 1) and ≤25?g/kg (experiment 2). Rice bran lysolecithin increased ready to cook weight at 50?g/kg during starter phase and decreased abdominal fat at 25 and 50?g/kg during finisher phase (experiment 2). Liver and meat fat content were not affected.

4. It is concluded that lysolecithin from rice bran oil could be used as energy supplement in broiler chicken diet.     

Mussel shells as an environment enrichment and calcium source for floor-housed laying hens

Feather pecking is still a behavioral problem in laying hen flocks, resulting in impaired welfare and economic losses. Environment enrichment, e.g., providing access to litter, to increase foraging behavior in laying hens has been shown to decrease feather pecking. This study investigated the effect of spreading crushed mussel shells (particle size 10 to 20 mm) in the litter area as an environment enrichment and source of calcium for layers receiving a commercial feed and for layers given a feed with 40% less calcium. These treatments were compared with a control involving hens given the commercial feed, but no mussel shells in the litter. The study included 900 Dekalb White layers housed in a single-tier floor system during a production cycle (20 to 72 wk of age). The mussel shells were consumed to a lower extent than predicted, resulting in calcium deficiency in hens fed the low-calcium diet. This in turn was evident as increased degree of keel bone deviations and lower eggshell breaking strength. Daily addition of crushed mussel shells to the litter for laying hens on a balanced or calcium-deficient diets did not generate any positive effects on bird feather cover, eggshell quality, production performance, or fearfulness. Hence, with the particle size of mussel shells used in this study, there was no indication of improved welfare due to environment enrichment.     

The use of rapeseed meals and a mustard seed meal as a protein source in diets for laying pullets

1. Three experiments with laying pullets were carried out in which rapeseed meals (B. napus and B. campestris) and a mustard seed meal (B. juncea) formed 12% of the diet.

2. Dietary rapeseed had no effect on the onset of lay when fed from 17 weeks of age but caused a delay when fed from 10 weeks of age: changing to a control soyabean diet for the laying period resulted in normal egg production.

3. Diets containing B. napus but not B. campestris consistently depressed egg production and reduced egg weight in one experiment. Mustard seed meal did not affect performance.

4. Significant number of eggs with a “fishy” taint were laid by brown‐egged birds fed on a diet containing rapeseed.

5. Thyroids of birds fed on rapeseed meal diets during the laying period were significantly heavier than those of birds fed on diets containing mustard seed or soyabean.

6. The enlargement of the thyroid gland is probably related to the oxazolidinethione content of the rapeseed.     

Use of carbohydrate and fat as energy source by obese and lean swine

Genetically obese and lean pigs were fed isonitrogenous-isoenergetic (digestible energy) amounts of a high or low fat diet from 25 kg body weight. Obese pigs gained less and required more feed per unit gain than lean pigs. Lean pigs were more muscular with less fat than obese pigs. Obese pigs utilized more dietary amino acids for energy (greater plasma urea N) than did lean pigs. Weight gain was similar at all intermediate periods in obese pigs fed the two diets. However, gain tended (P less than or equal to .10) to be greater and the ratio of dietary energy intake to gain tended (P less than or equal to .10) to be less in obese pigs fed high compared with low fat diets. Similar results were observed in lean pigs fed the two diets. The high fat diet produced more carcass adipose tissue deposition in both strains after 20 wk of feeding (detectable by ultrasound at 14, but not at 7 wk). Adipose tissue lipogenic rate (glucose incorporation) was similarly depressed by fat feeding in both obese and lean pigs. Obese and lean pigs both utilized dietary carbohydrate and fat differentially but there was no indication of genetic divergence regarding this utilization. In both strains of pigs, energy from the fat-enriched diet was preferentially partitioned into carcass adipose tissue.     

Effects of energy concentration and duration of feeding on the response of broiler chicks to growth promoters 1

1. Two experiments were carried out with male broiler chicks from 7 to 49 d of age to evaluate the combined effect of the growth promoters (GPs) avoparcin (AVO, 20 mg/kg), Zn bacitracin (BAC, 25 mg/kg) and nitrovin (NIT, 18 mg/kg), and dietary energy concentration (EC) (experiment 1) and the effect of age of feeding AVO (experiment 2) on performance, utilisation of dietary nutrients, yield of defeathered eviscerated carcases (DEC) and size of various organs.

2. AVO, in contrast to BAC and NIT, significantly (P<0–05) decreased fat excretion and increased dry matter, fat and nitrogen retention, dietary AME_n content, weight gain and food efficiency. AVO also significantly decreased the size of the liver and the small intestine (SI), the length of the SI and its specific weight. The effect of BAC and NIT on the variables of the SI was less pronounced than that of AVO. Although the effect of AVO on increasing fat retention, growth and food efficiency was more pronounced with the high EC diet, neither of the variables of performance, nutrient utilisation (except for fat retention) or organ size, was significantly affected by the interactions between GPs and dietary EC.

3. AVO fed continuously or from 28 d of age significantly improved food efficiency during 7 to 49 d of age, increased the yield of DEC and decreased the size of the liver and the SI, the length of the SI, and its specific weight. None of these effects was observed when AVO was omitted from the diet at 28 d of age. Feeding AVO from 28 d of age did not improve weight gain during the entire period, as did the continuous feeding of this GP.

4. It is concluded that BAC and NIT are not effective as GPs under the conditions of the present study. The effect of AVO on improving performance and on carcase characteristics is hardly dependent on dietary EC. Feeding AVO from 28 to 49 d of age improves food efficiency and has similar effects on carcase characteristics to those of continuous feeding.     

复合酶在三黄肉鸡降能日粮中的应用研究

试验选用健壮、活泼且均匀的1日龄快大型粤禽黄肉鸡960羽，随机分为4个处理，每个处理6个重复，每重复40羽，进行为期50d的饲养试验。试验以珠海某饲料厂的三黄肉鸡料为基础日粮，研究在基础日粮的基础上分别降低252、336和420kJ／kg代谢能，并研究添加1kg/t溢多酶9680（分别添加在试验1组、试验2组和试验3组）对肉鸡的平均日增质量、饲料转化率和存活率的影响，并进行生物学综合评定。试验结果显示，3个试验组的日采食量、平均日增质量和成活率与对照组相比差异均不显著。与对照组相比，3个试验组小鸡阶段的料肉比分别下降了9．25％、2．31％和4．05％，其中试验1组达到了显著水平，其余2组差异均不显著；中鸡阶段的料肉比分别下降了3．49％、1．75％和3．93％，差异均不显著；试验1组和试验3组大鸡阶段的料肉比分别下降了5．14％和3．71％，差异均不显著。3个试验组的全期成活率与对照组相比分别提高了3．05％、2．56％和8．16％，其中，试验3组达到了极显著水平，其余2组差异均不显著。生物学评定结果显示，试验组小鸡、中鸡、大鸡及全期的生物学综合评定值均≥100，这说明，在珠海某公司三黄肉鸡料中添加1kg/t溢多酶9680，其日粮代谢能降低幅度控制在420kJ／kg范围内时，不仪不会对肉鸡的生产性能产生不利影响，而且还在一定程度上改善了肉鸡的生产性能。     

Metabolisable energy,nitrogen absorbability and feeding value of expeller processed mustard cake for chicks

Four experiments were carried out to compare the nutritional indices of expeller processed mustard cake (MS) with that of groundnut cake (GN). The indices measured were metabolisable energy (ME), nitrogen absorbability and growth rate. The average ME values of MS and GN were 2.19 Mcal/kg (9.16 MJ/kg) and 2.75 Mcal/kg (11.51 MJ/kg) respectively. The apparent nitrogen absorbabilities were 63.3% and 67.5% respectively, when the chicks were fed on assorted sources of protein containing either of the cakes but were 70.8% and 73.7% respectively when these cakes served as the sole source of protein in the diet. Although ME content and nitrogen absorption of MS were lower than GN its feeding value was similar when growth and food conversion were compared.