Influence of steam pelleting on the feeding value of Tower and Candle rapeseed products for broiler chickens

Male broiler chickens were offered diets containing up to 30% Tower rapeseed meal, with these diets being prepared in mash or steam pelleted (crumble) form. In 4 experiments, birds receiving a maize and soya bean meal control diet showed a significant improvement in weight gain when crumbles, rather than mash diets, were used. With isocaloric, isonitrogenous diets containing rapeseed meal, no such improvement in growth rate was observed. Steam pelleting exerted no consistent effect on feed conversion. There was no significant difference in the growth rate of birds receiving mash diets irrespective of composition, while for crumbled diets, birds consuming the maize and soya bean control diet were heavier than comparable rapeseed-fed birds, with this difference being significant in 2 experiments. By adding fat, necessary to maintain rapeseed diets isocaloric, after the pelleting process, it was shown that fat per se was not responsible for failure to elicit a growth response with pelleted rapeseed meal diets. The response to pelleting was similar with diets prepared in an experimental pelleting machine at the university or by a commercial feed mill. Reduction in amino acid availability, in particular of arginine, is tentatively discussed in relation to the non-improved growth rate observed with pelleted diets containing rapeseed meal. Improvement in growth rate with pelleted vs. mash diets containing whole, raw rapeseeds is interpreted as a response to the heat treatment involved with the pelleting process.     

The nutritive value of Tower rapeseed meal for swine

Two experiments involving 144 Yorkshire × Lacombe gilts, with an average initial weight of 20 kg, were conducted. In Experiment 1 the gilts were allotted to a control diet containing soya bean meal (SBM) or to diets in which either 50% or all of the supplementary protein was provided by Tower rapeseed meal (RSM). In the second experiment the two diets had either SBM or Tower RSM as the supplementary protein source. In a third diet Tower RSM was supplemented with sufficient lysine to equal the calculated available lysine level of the SBM control diet. In Experiment 1, gilts given the SBM diet grew from 20 to 60 kg significantly faster (P<0.01), and had better feed conversion efficiency (P<0.01), than those given the RSM diets. A 50% replacement of SBM by Tower RSM gave intermediate results. Partial or total replacement of SBM by Tower did not significantly affect the growth rate or feed conversion efficiency of the gilts when growing from 60 to 100 kg liveweight. Serum triiodothyronine (T3) and thyroxine (T4) concentrations of the gilts at 100 kg were lower in pigs fed on the RSM diets but the differences were not significant. In the second experiment, total replacement of SBM by Tower RSM, with or without the addition of lysine, significantly (P<0.001) reduced growth rate and feed conversion efficiency during the growing period (20–60 kg) but did not significantly affect performance during the finishing period (60–90 kg). Serum T3 concentration was not significantly affected by the addition of Tower RSM to the diet but T4 concentrations were significantly reduced (P<0.01). None of the carcass parameters studied were significantly affected by the addition of Tower RSM to the diets.     

The effects of cereal particle size and pelleting on the nutritive value of oat-based diets for the growing pig

Oat grains from a single source were ground in a hammer mill, either with no screen present (coarse) or through 1.56 or 4.68-mm screens, to produce three samples with different particle size distributions. At inclusion levels of 850 g kg^?1 the three samples were used as the bases of three otherwise identical diets. Half of each diet was steam pelleted to give pellets of 7-mm diameter and the other half retained as a meal form. Factorially designed metabolism experiments using 30 pigs of 20 kg initial live weight and a growth experiment using 72 individually fed pigs of 25 kg initial live weight were made.Pelleting or particle size of the diet had no significant effect on (a) apparent digestibility of dry matter (DM), modified acid detergent fibre and gross energy (b) digestible (DE) and metabolisable energy (ME) contents (the DE contents of the meal and pelleted diets were 12.81 and 13.03 MJ kg^?1 DM, respectively) and (c) nitrogen retention. Apparent digestibility of the ether-extractable fraction was significantly poorer in meals (cf. pellets) and in the diets based on coarse grains compared with those based on the two finer-ground samples. Also, apparent digestibility of nitrogen was significantly poorer in the diets based on the coarse grains (0.803) compared with that based on the 1.56-mm ground grain (0.832). Growth and efficiency of feed conversion were significantly improved by pelleting the coarse grain diet, and the meal diet based on the coarse grain gave significantly inferior results compared with those from the two other meal diets.     

Fine grinding or expanding of feed as pre-treatment for pelleting in dependence on dietary rapeseed expeller proportion: Nutritional consequences for broilers

Although commercial broiler feed is usually differently conditioned before pelleting, the nutritional consequences of fine grinding or expanding as pre-pelleting treatments are poorly defined so far. Therefore, the effects of these two pre-treatments on nutrient digestibility, broiler performance and digestive tract of broilers were tested. In order to investigate possible interactions between pre-treatments and diet composition two diets differing in rapeseed expeller proportion were tested in a two by two factorial design. Thus, four diets were designed including two diets containing 6% rapeseed expeller (RSE) which were pre-treated by fine grinding (6%FgP) or expanding (6%ExP), and two corresponding diets containing 12% RSE (12%FgP and 12%ExP). For the experiments, 864 male broilers were used. There was a significant diet-by-technical feed treatment (TFT) interaction in case of the digestibility of all considered crude nutrients (p < 0.05). Diet 6%ExP showed higher crude protein digestibility compared to other feeds (p < 0.001). The highest digestibility of organic matter, ether extract, crude fibre and N-free extractives achieved diet 12%FgP. Diets 6%ExP and 12%FgP showed higher N-corrected metabolisable energy content (p < 0.001). TFT affected daily feed intake (DFI) and body weight (BW) gain in a diet-dependent manner (p < 0.001). Feeding of 6%FgP enhanced DFI and BW gain compared to other feeds but 6%ExP reduced both parameters (p < 0.001). Weights of proventriculi and gizzards of animals fed 6%ExP were increased compared with 6%FgP (p < 0.01). In contrast, proventricular length in animals fed 6%FgP was increased compared with diet 6%ExP (p = 0.042). Moreover, animals fed 6%FgP had wider proventriculi than animals fed 12%FgP (p = 0.023). Feed 6%ExP increased proventricular weight compared to 12%ExP (p = 0.001). With regard to the strong relationships between diet and TFT no specific processing method can be recommended according to considered nutritional aspects. A marked prevention of proventricular dilatation due to pellet feeding could not be realised by various used TFT or feed formulations. Used amounts of RSE had no obvious adverse effects on considered nutritional aspects.     

Impact of wheat grinding and pelleting in a wheat–rapeseed meal diet on amino acid ileal digestibility and endogenous losses in pigs

The purpose of the current experiment was to investigate the impacts of grinding and pelleting procedures applied to wheat in a wheat–rapeseed meal diet on the coefficients of standardized ileal digestibility, i.e., apparent digestibility corrected for basal endogenous losses (CSID), and true ileal digestibility, i.e., apparent digestibility corrected for total endogenous losses (CTID), of nitrogen (N) and amino acids (AA) in pigs. Ileal digestibility was measured by collecting digesta from pigs fitted with ileorectal anastomoses. Four diets, involving four technological treatments applied to wheat, were compared in vivo according to a 4 × 4 Latin square design (four pigs each fed four diets during four successive periods of 1 week). The technological treatments of wheat were two grinding procedures and two pelleting processes. Wheat was ground to obtain mean flour particle sizes of 1000 and 500 μm, leading after mixing with rapeseed meal and minerals-vitamins premix to the first and second diets named “coarse” and “fine”, respectively. Part of the 500 μm wheat flour was pelleted through dies of same screen diameter (4 mm) but different thicknesses, 16 and 20 mm, inducing a low and high compression ratio, leading after mixing with rapeseed meal and premix to the third and fourth diets named “LCR” and “HCR”, respectively. Basal endogenous losses were determined by feeding a protein-free diet during the 5th week of the experiment. Total endogenous losses were measured by way of the isotopic dilution method using ¹⁵N-labeled wheat and rapeseed meal. Decreasing wheat particle size from 1000 to 500 μm improved (P<0.05) the coefficient of ileal digestibility of dietary energy (0.707 versus 0.665), organic matter (0.718 versus 0.677) and dry matter (0.681 versus 0.645), but neither AA CSID nor N retention. The pelleting processes did not further increase (P>0.10) energy or organic matter digestibility but improved (P<0.05) N and AA CSID (0.785 versus 0.759 for N and 0.725 versus 0.679 for lysine, with HCR versus fine diet, respectively). Pelleting wheat flour at higher compression ratio (HCR versus LCR diet) was more efficient to improve dietary N and AA digestibility values due to a significant decrease in ileal specific, i.e., total minus basal, N and AA endogenous losses (P<0.05) associated with an increase in CTID. It is concluded that pelleting wheat fine flour at high compression ratio allows maximizing AA digestibility and availability of a wheat–rapeseed meal diet.     

The effect of ammoniation on the intake and nutritive value of straw

Studies were conducted to compare the increases in dry matter digestibility (DMD) in vitro and in vivo and to determine the metabolisable energy (ME) value of straw ammoniated at ambient temperature. Two stacks of straw sealed with polyethylene were allowed to react with 3% (w/w) anhydrous NH₃ for 30 and 56 days, respectively. Both DMD in vitro and nitrogen tests were carried out over an eight-week period subsequent to opening the stacks. Digestibility in vivo was measured with 12 wether lambs. The non-treated and ammoniated straws were given ad libitum, with a supplement of either ground barley or a lamb concentrate which contained 16% crude protein (CP).There was a mean increase of 15 percentage units in DMD in vitro for the ammoniated straw irrespective of whether it was treated for 30 or 56 days. The corresponding increase in mean DMD in vivo was 14.2 units. The CP content of the straw was increased from 3.1 to 7.6%. The increase in DMD in vitro and total N content was maintained throughout the sampling period. Approximately 58% of the anhydrous NH₃ added to the straw appeared to have been irreversibly “bound” to the straw. The ME values for the ammoniated straw were 6.78 and 7.49 MJ/kg when the straw was supplemented with either barley or the lamb concentrate, respectively. Straw ammoniation had a marked effect on intake. The overall increase in intake was 70% for the treated compared with the non-treated material.     

The effect of nutrient supplementation on the feeding value of kapok seed for poultry

Two feeding trials were conducted with day-old New Hampshire chicks to determine whether addition of certain nutrients improved the feeding value of kapok seed in poultry diets. The seeds were used either raw (RKS), after oven drying (ODKS) at 100°C for 2 h or after water extraction (WEKS). In Trial 1, ODKS was used at the 5% level of incorporation. To this diet extra vitamins, oleic acid, methionine and lysine were added either individually or together, and it was given for 4 weeks. The control group of birds (no kapok seed) gained 305 g, as against a gain of 243 g of birds on the RKS diet and 127 g on the ODKS diet. Addition of nutrients to the ODKS diet significantly improved weight gain. There was also a marked improvement in livability. Addition of extra vitamins, oleic acid, lysine and methionine was highly beneficial, in the case of the 5% RKS diet, in restoring growth rate compared with the control; however, the beneficial effect was only partial when the level of RKS was increased to 10%, as in Trial 2. Feeding of the WEKS diet failed to show a marked improvement in the growth rate of chicks. Feeding with raw or processed kapok seeds decreased the packed cell volume and haemoglobin content, but this adverse effect was partially overcome by nutrient supplementation.     

Evaluation of the nutritive value of maize for honey bees

In modern managed agro-ecosystems, the supply of adequate food from blooming crops is limited to brief periods. During periods of pollen deficiencies, bees are forced to forage on alternative crops, such as maize. However, pollen of maize is believed to be a minor food source for bees as it is thought to be lacking in proteins and essential amino acids. This study was conducted to verify this assumption. In maize, a strikingly low concentration of histidine was found, but the amount of all other essential amino acids was greater than that of mixed pollen. The performance and the immunocompetence of bees consuming a pure maize pollen diet (A) was compared to bees feeding on a polyfloral pollen diet (B) and to bees feeding on an artificial substitute of pollen (C). Consumption of diets A and C were linked to a reduction in brood rearing and lifespan. However, no immunological effects were observed based on two parameters of the humoral immunity.     

The digestibility and nutritive value for dairy heifers of rations containing cellulose fibre

Cellulose residue (cellufiber) from an ammonium base acid sulphite paper process was accepted by dairy heifers to the extent of 40% of the dry matter of an all-roughage ration when mixed with maize (Zea mays) silage at time of feeding. No adverse physiological effects were observed during digestion trials lasting 80 days in which cattle were given successively diets containing 10, 20, 30 or 40% of the ration dry matter as cellufiber. Apparent digestibility of crude protein decreased and digestibility of crude fibre and acid detergent fibre increased as the cellufiber level in the ration increased. Digestibility coefficients of dry matter, nitrogen-free extract and gross energy were unaffected.Uniformity of values for total digestible nutrients, digestible energy and metabolizable energy and, also, of the body weight gains by the test animals indicated only small differences in nutritive value between rations. However, estimated nutritive values of ration components indicated appreciable differences. The TDN of cellufiber was 56% which was approximately equal to that of alfalfa (Medicago sativa) hay and was 82% of the value of maize silage. However, the digestible energy value of cellufiber (1.93 Mcal/kg DM) was only 77% of alfalfa hay and 69% of maize silage. Similarly, its metabolizable energe value of 1.41 Mcal/kg DM was 69% of that of alfalfa hay and 61% of that of maize silage.     

The influence of phytoplankton composition on the relative effectiveness of grinding and sonification for chlorophyll extraction

The chlorophyll recovery efficiency was compared between control, ground, and sonified samples. The results showed significant improvement between control and ground samples but not between control and sonified samples. Neither prolonging time of sonification nor using an ice bath during filter grinding improved efficiency. Higher chlorophyll a recovery was obtained from ground samples than from sonified ones, when the water samples contained centric diatoms and filamentous blue-green algae. When total phytoplankton numbers were high, there was a distinct advantage in using grinding rather than sonification for chlorophyll c recovery.Contribution no. 313 of the Great Lakes Research Division, University of Michigan.Contribution no. 313 of the Great Lakes Research Division, University of Michigan.     

Nutritive value of poultry wastes for sheep

The present study included four successive experiments to determine the chemical composition of the manures and the effects of including varying levels of poultry manure in sheep rations on nutrients digestibility, nitrogen balance and the possible adaptation to the experimental diets as the experimental period was prolonged. Four different poultry wastes were used. These wastes were: pure layer droppings, HELWAN (Experiment I); pure layer droppings, SAKHA (Experiment II); layer litter (Experiment III); and broiler litter (Experiment IV). Three levels of each waste (0, low and high) were tested in the rations of six mature Ossimi fat-tailed rams (two animals for each treatment).Results showed a wide variation in ash and crude protein contents of the different wastes. Layer droppings (HELWAN) contained the highest ash percentage (43·9), while broiler litter contained the lowest (18·8). For crude protein content, broiler litter had the highest value (34·0%) and layer droppings (SAKHA) the lowest (15·4%).Feed intake (g OM per kg^0.75 day⁻¹) decreased with increasing level of manure. Water intake and excretion were, in general, related to food and minerals intake. Feed intakes sometimes improved with advancing experimental period. In most experiments, digestibilities of ash and crude fiber increased while those of other components decreased with the inclusion of the waste materials in the diets.In vitro DMD or OMD were lower for diets containing waste materials than the control diets.Results of some rumen liquor parameters are tabulated and discussed.     

The effect of steam-conditioning rate on the pelleting process

A poultry layer-diet was used in experiments to determine the effects of steam-conditioning level on pelleting variables. Dry pelleting was compared with steam conditioning (to 65 and 80° C) before pelleting, at both constant and maximum production rates. Samples were obtained before and after conditioning, and after pelleting. Electrical energy used by the pellet mill was measured with a watt-hour meter, and the amount of steam used for conditioning was calculated using steam tables. Temperature rise of the meal being extruded through the die and electrical energy required to pellet showed that steam decreased mechanical friction during pelleting. Pellet durability and percentage of fines from the scalper showed that steam improved pellet quality. Pressing the mash through the pellet die caused more starch damage during dry pelleting than during steam pelleting. Starch was not damaged during the steam-conditioning process. Total energy required for pelleting (electrical plus steam) was highest for the 80° C treatment. However, steam conditioning allows increased production rates and improved pellet durability during handling and transportation of finished feeds.