Nutritive value of triticale fed to cockerels and chicks

1. The chemical composition, and amino acid and starch bioavailabilities of 18 triticale varieties were studied. In addition, the water soluble pentosan (WSP) content of 8 varieties was determined.

2. A wide variation in protein (149 to 203 g/kg DM), starch (563 to 629 g/kg DM) and WSP (27·7 to 50·9 g/kg DM) was found between varieties.

3. The TMEn reproductibility was assessed in two laboratories, using Leghorn cockerels, Isabrown cockerels and 3‐week‐old chicks. There were no sismificant differences in the TMEn values (range 14·0 to 15·2 MJ/kg DM) between the two types of cockerel. The TMEn values of the varieties were similar for chicks (range 13·6 to 14·9 MJ/kg DM) and for cockerels, with the exception of one variety.

4. The bioavailability of starch (range 96·5 to 99·4%) of some varieties was higher for cockerels than for chicks. The mean bioavailability of amino acids for cockerels was 94·5%.

5. TMEn prediction equations were derived from the chemical composition of the varieties. Best‐fit equations were obtained for starch (R ² = 0·62, RSD = 0·24), ash (R ² = 0·58, RSD = 0·25) and WSP (R ² = 0·52, RSD = 0·27).     

Studies on the incorporation of triticale in diets for growing chicks

1. The classical ME value of triticale varied from 12.305 to 13.778 kJ/g or 11.819 to 13.016 kJ/g corrected for N‐retention depending upon method of calculation.

2. Substituting triticale for maize, weight for weight, but not on a iso‐nitrogenous basis, in a groundnut oil cake (GNC) starter diet improved weight gain (P < 0.05) when the substitution exceeded 75% without affecting the protein efficiency ratio (PER).

3. A similar substitution in a soybean oil meal diet, improved weight gain (P < 0.05) at 50% or more but PER declined (P < 0.05).

4. The net protein utilisation and protein retention efficiency values of the diets in which maize protein was replaced by triticale protein were significantly reduced.

5. The maize‐GNC diet was equally limiting in methionine and lysine while the triticale‐GNC diet was not.

6. The growth and food efficiency obtained with a triticale‐GNC diet was higher (P < 0.01) than with the maize‐GNC diet but not with a maize‐GNC supplemented with fish meal and methionine.

7. It is concluded that triticale could quantitatively substitute maize in the starter diets.     

Incorporation of triticale in layer diets

1. Diets containing either maize or triticale were fed unsupplemented or supplemented with meat meal or groundnut oil to White Leghorn pullets for two periods of 11 weeks each.

2. The egg production of birds fed on the unsupplemented triticale diet was significantly higher than that of the birds fed on the unsupplemented maize diet, but was not significantly different from that of the birds fed on the maize plus meat meal diet.

3. Protein quality of the unsupplemented triticale diet as judged by efficiency of nitrogen retention was similar or inferior to that of the unsupplemented maize diet.

4. The higher protein content of triticale and the increased intake of these diets seemed to be responsible for the better performance observed.

5. Addition of groundnut oil to the triticale diet did not improve either egg weight or production.

6. It is concluded that the quantitative substitution for triticale of maize does not adversely affect egg production and egg weight.     

A comparative study between mature ostriches (Struthio camelus) and adult cockerels with respect to true and apparent metabolisable energy values for maize,barley, oats and triticale

1. In three successive trials with cockerels and mature ostrich males the apparent and true metabolisable energy values, corrected for nitrogen retention (AME_n and TME_n) were determined by a balance method for malting barley, oats, triticale and yellow maize. All these ingredients were used as sole dietary components with the exception of triticale for ostriches which was diluted with 440 g/kg lucerne meal. The balance trial lasted for 5 d after an adaption period of 7 d for ostriches, and 3 d after an adaption period of one day for cockerels.

2. AME_n values for cockerels of malting barley, oats, triticale and maize were 11.6, 10.48, 11.44 and 14.42 MJ/kg respectively. Significantly higher values of 14.21, 12.65, 12.60 and 14.89 MJ/kg were determined for malting barley, oats, triticale and maize for ostriches.

3. TME_n values determined by regression yielded values in ostriches of 13.92, 12.27, 13.21 and 15.22 MJ/kg for malting barley, oats, triticale and maize respectively. The corresponding TME_n values in cockerels were 11.33, 10.63, 11.82 and 14.07 MJ/kg.

4. The ostrich is capable of utilising fibre more efficiently than poultry. The higher energy values observed for the various ingredients also indicated that the non‐starch polysaccharides such as ß‐glucans and arabinoxylans in the more fibrous energy sources had little if any effect on the available energy of these ingredients as found with poultry.

5. The potential of ostriches to utilise the more fibrous energy sources like barley, oats and triticale allows for their economical use in diet formulation. This possibility may result in markedly lower food costs for ostriches.     

Effects of faba bean tannins on the growth and histological structure of the intestinal tract and liver of chicks and rats

1. Diets containing a freeze‐dried tannin extract from faba beans (Vicia faba L.) at concentrations of 0, 8 and 16 g/kg were fed to growing chicks and rats.

2. Chicks fed on the tannin‐containing diets exhibited a high mortality and significant decreases in body‐weight as well as lower food intakes and higher food intake:weight gain ratios (P<0.01). In rats there was no mortality but the growth and food intake were adversely affected (P< 0.05).

3. Histological changes occurred in the ileal mucosa of chicks. Atrophy and shortening of villi with distortion of their architecture were observed. Similar histological disorders but less pronounced were also found in rats.

4. Histopathology of the liver of both chicks and rats showed an hydropic degeneration of hepatocytes, clearly more severe in the former than in the latter.     

Replacement of maize by triticale in broiler diets

1. The nitrogen‐corrected metabolisable energy contents of the triticale varieties Multi Graze, Graze Grain 70, 204 and 131 were 12.28, 12.69, 12.37 and 12.03 MJ/kg respectively.

2. Increasing proportions (0, 25, 50 or 75%) of the maize of a diet were replaced by triticale 131 to provide diets of equal energy and nitrogen contents for broilers. These diets resulted in weight gains of 1.775, 1.782, 1.713 and 1.808 kg respectively at 8 weeks and there were no significant differences among efficiencies of food conversions.

3. Dressed carcass weights as percentages of body weight were 74.38, 75.01, 73.98 and 74.50 respectively and did not differ significantly.

4. Triticale in the diet did not seem to influence the relative weights of either liver or gizzard.

5. The flavour of the meat seemed to become less acceptable as the triticale in the diet increased but there were no significant differences in tenderness and juiciness of the meat caused by the treatments.     

Attempts to eliminate from field beans the anti‐nutritive factor which reduces egg production

1. In a series of experiments with laying hens, attempts were made to eliminate the anti‐nutritive factor which reduces egg production when feeding field beans (Vicia faba L.) as a source of supplementary protein in cereal‐based diets.

2. Neither pelleting diets nor heat processing the beans by autoclaving proved beneficial. A continuous‐flow process for infra‐red heating of the seeds at 150 °C for 70 s followed immediately by flaking (micronisation) gave inconsistent results.

3. Beans having a white skin with associated low tannin content, did not support significantly higher egg production than did a normal brown‐skinned bean, thus indicating that tannin was not the main anti‐nutritive factor.

4. A cotyledon fraction, obtained by mechanical removal of the tannin‐containing skin from brown beans, did not support higher egg production than did the whole bean, and the corresponding brown‐skin fraction did not reduce egg production when substituted for cereal in the control diet. Again this indicated that tannin was not implicated.     

Measurement of endogenous amino acid losses in poultry

1. Ileal endogenous amino acid losses were determined in broiler chickens and in cannulated cross‐bred layer strain cockerels using either a nitrogen‐free diet, regression analysis or a 48 h fast.

2. Endogenous amino acid flows to the ileum in fasted cockerels were significantly lower than those obtained both by feeding the nitrogen‐free diet, and from regression analysis in either broilers or cockerels. Regression analysis gave the highest flows.

3. The apparent digestibility coefficients of amino acids in a diet containing 200 g/kg crude protein were lower in broilers (0.84) than in cockerels (0.88). When corrected, by regression analysis, for the contribution of endogenous amino acids, the true digestibility coefficients became 0.90 and 0.92 respectively.     

The possible role of methionine in the detoxification of faba bean (Vicia faba L.) tannins in chick diets

1. A metabolism trial was designed to investigate the role of methionine as a specific detoxifying agent of the condensed tannins present in faba beans (Vicia faba L.).

2. A 5 x 5 factorial approach was employed where 5 concentrations of dietary methionine were obtained (ranging from 3.9 to 12.15 g/kg diet dry matter) by the addition of DL‐methionine, and 5 concentrations of condensed tannins (ranging from 0.5 to 19.7 g/kg diet dry matter) by altering the ratio of tannin‐free and tannin‐containing faba bean hulls added to a basal diet.

3. The intake of condensed tannins had a significant, depressive effect on apparent available nitrogen (P< 0.001) and nitrogen corrected apparent metabolisable energy (AME_n ) (P< 0.001). There was no interaction between methionine and tannin (P>0.05). Thus the depressive effect of tannin was independent of methionine levels in the diet.

4. Methionine does not act as a specific detoxifier of faba bean condensed tannins.     

Sudies on low metabolisable energy wheats for poultry using conventional and rapid assay procedures and the effects of processing

1. A significant proportion of wheat cultivars grown in New South Wales had low apparent metabolisable energy (AME) values (< 13.0 MJ/kg dry matter) for growing broilers when determined by the conventional total collection technique.

2. The low AME was due to a reduced starch digestibility and was not improved by grinding the wheat finely or by steam pelleting the diet.

3. Higher AME values were obtained when determinations were made with adult cockerels than with growing broilers when the conventional technique was used.

4. AME values determined using a rapid bioassay technique (Farrell, 1978) with growing broilers or adult cockerels were considerably higher than values determined using the conventional procedure with growing broilers.

5. Inter‐laboratory studies showed that the true metabolisable energy (TME) assay gave reproducible values for individual and blended wheat samples, but that these values were higher than AME values determined by the conventional procedure. Similar TME values were found with growing broilers and adult cockerels.     

Influence of caecectomy and dietary protein concentration on apparent excreta amino acid digestibility in adult cockerels

1. The influence of caecectomy and dietary crude protein content (50, 100, 150, 200 and 250 g/kg diet) on the apparent excreta amino acid digestibilities in adult cockerels fed on semi‐purified diets containing soyabean meal (SBM) or cottonseed meal (CSM) as the sole source of protein was investigated.

2. Caecectomy had no influence on the apparent digestibilities of most amino acids in SBM, the exceptions being histidine, arginine and lysine, but lowered the apparent digestibility of amino acids in CSM.

3. The protein content in assay diets has a strong influence on the apparent amino acid digestibility values for poultry. Apparent values are lower when the dietary protein content is low.

4. The use of a single endogenous amino acid output value, generated by regression analysis or protein‐free diets, for true digestibility adjustments across a wide range of protein intakes is questioned. In particular, such an application will penalise estimates of apparent digestibility when the dietary protein content is high.     

Influence of site and variety on starch,hemicellulose and cellulose composition of wheats and their digestibilities by adult cockerels

1. It has been shown that both the variety of wheat and the environment under which growth took place influenced the quantities of starch and cell wall carbohydrate contents of wheat.

2. The different varieties of wheat investigated contained different proportions of water‐soluble to water‐insoluble hemicelluloses.

3. By comparison of the arabinose to xylose ratios it was concluded that water‐soluble and insoluble arabinoxylans of wheat were branched to the same degree.

4. Starch from six wheat varieties grown in the U.K. was very well digested by adult cockerels and true metabolisable energy values of the wheats were high.

5. Small amounts of cell wall carbohydrates were digested by adult cockerels.     

Comparison of maize,wheat and triticale in broiler diets

1. Wheat, triticale 131 or triticale 72‐S could replace up to half the maize in broiler diets without affecting performance. Replacing more of the maize on either an equal nitrogen basis or a weight basis adversely affected performance.

2. Triticale 72‐S appeared to be superior to triticale 131 as a direct replacement for maize, but both grains were inferior to maize as energy sources.     

The nutritive value of triticale and rye for the laying hen

1. The crude compositions of samples of triticale and rye are given together with more detailed analyses for the protein and carbohydrate fractions.

2. By regression analysis of absorption on intake, the true digestibilities of the crude protein, using colostomised birds, were calculated to be 85.2 and 72.0%, those of the crude fat 94.4 and 89.7% and those of the carbohydrate 82.0 and 75.5% for triticale and rye respectively.

3. The classical metabolisable energy values of the triticale and rye samples were found to be 14.08 and 12.51 MJ/kg (3.36 and 2.99 Mcal/kg) respectively.

4. It is concluded that triticale is a better food source for the chicken than either wheat or rye.     

Effects of dietary sorghum of different tannin concentrations and tallow supplementation on the performance of broiler chicks

1. The chemical compositions and tannin contents of 17 varieties of grain sorghum were determined.

2. Commercial broiler chicks were fed from 7 to 49 d of age on 15 experimental diets which varied in their concentrations of tannins and animal fat (tallow), by the inclusion of different amounts of high and a low protein varieties of sorghum.

3. Substitution of a low tannin sorghum completely for maize did not have any significantly adverse effect on performance. Broiler chicks could tolerate up to 2.6 g tannin/kg above which their performance was reduced. Addition of tallow did not significantly affect broiler performance except at the highest tannin content and added fat intake, where weight gain and efficiency appeared to improve significantly.     

The nutritive value of triticale and rye in broiler diets containing field beans (Vicia faba L.)

1. Diets containing wheat and maize (control), 300 g or 500 g triticale per kg or 300 g rye per kg were fed to broiler chickens for 56 d.

2. Live‐weight at 56 d of age was not different on a diet containing 300 g triticale per kg to that on the control diet but was significantly reduced by diets containing 500 g triticale or 300 g rye per kg.

3. Food conversion efficiency was best with 300 g triticale per kg of diet.     

The effect of heat treatment and enzyme supplementation on the nutritive value of barley for broiler chicks

1. The effect of heat treatment and enzyme supplementation on the nutritive value of barley was studied.

2. In only one experiment was weight gain significantly improved when the barley was heated.

3. Autoclaving barley at 120 °C for 30 min reduced dietary dry matter digestibility and treating the barley with dilute acid before heating had no effect on its nutritive value.

4. Supplementing diets containing commercial barley with a‐amylase produced slightly conflicting results in that there was an improved weight gain, food conversion efficiency and digestibility value in two of three experiments.

5. The digestibility and metabolisable energy values of a North American six‐row spring barley (Glacier) were significantly improved by enzyme supplementation.

6. The effect of the enzyme on diets containing a high amylose barley (Glacier Pentlandfield) was positive but not significant.     

Use of field beans (Vicia faba L) in diets for laying hens

1. Most samples of field bean, irrespective of their genetic origin, induced a decrease in the mean egg weight when included in the diet at a rate of 300 g/kg: the relative sizes of yolk, albumen and shell were unchanged.

2. Lipoxygenase was not involved in this phenomenon since addition of linoleic acid to the diets containing field beans did not improve egg weight.

3. The depressing effect of the field beans was proportional to the proanthocyanidine content of the seed extracted with absolute methanol.

4. In a longer trial (252d) field beans rich in these kinds of tannin decreased laying rate, efficiency of food utilisation and tended to increase mortality.

5. The removal of the hulls from the field beans did not prevent the reduction in egg weight.     

A comparative study between mature ostriches (Struthio camelus) and adult cockerels with regard to the true and apparent digestibilities of amino acids

1. A study was conducted to compare apparent and true digestibility of amino acids in a high protein experimental diet between young ostriches (7 months of age) and cockerels.

2. A mean value for true digestibility of amino acids (TAAD) of 0.837 ± 0.0073 (range 0.780 to 0.862) was derived for ostriches, compared with a mean value of 0.795 ± 0.0258 (range 0.723 to 0.825) for cockerels.

3. True retention of dietary protein was 0.646 ±0.0114 and 0.609 ±0.0643 for ostriches and cockerels respectively.

4. Results in the present study produced evidence that the method for determining metabolisable energy values of ingredients for ostriches is also suitable for measuring the digestibility of amino acids.

5. It was concluded that accurate diet formulation for ostriches requires the assessment of amino acid digestibilities for individual ingredients, because values derived from poultry would underestimate digestibilities for ostriches.     

Effects of high inclusion rates of salseed meal in the diet of chicks

1. Starter diets containing either maize or salseed meal to replace the maize were fed to chicks over a period of 2 weeks.

2. Growth rate, food intake, food utilisation and proportion of dietary nitrogen retained were much poorer in chicks receiving salseed meal.

3. The chicks receiving salseed meal developed pathological lesions in liver and kidney.

4. The red blood cell count, white blood cell count, haemoglobin concentration and packed cell volume of the chicks receiving salseed meal were lower than those of chicks receiving maize.

5. The apparent metabolisable energy value of salseed meal was determined as 6.83 MJ/kg.