The effects of barley, unmolassed sugar-beet pulp and molasses supplements on organic matter, nitrogen and fibre digestion in the rumen of cattle given a silage diet

In a 4 × 4 Latin-square experiment with a 2 × 2 factorial arrangement of treatments, 4 cattle fitted with a rumen and duodenal cannula were given four grass-containing diets [480 g kg⁻¹ of the total dry matter (DM) intake] and barley (BU), barley + molasses (2:1) (BM), sugar-beet pulp (SU) or sugar-beet pulp + molasses (SM). Duodenal flow was estimated using Cr-mordanted straw and CoEDTA as markers, and microbial nitrogen entering the small intestine using purine bases of nucleic acids.

Molasses-containing diets had a higher (P < 0.01) organic matter (OM) digestibility. The proportion of digestible OM apparently disappearing in the rumen averaged 0.72 and was not significantly affected by the diet. When cattle received molasses, the quantity of microbial N entering the small intestine was higher (P < 0.05) and there was a trend towards a higher efficiency of microbial N synthesis (28.8 vs. 25.6 g N kg⁻¹ OM apparently digested in the rumen). When S diets were consumed, total non-ammonia N flow at the duodenum exceeded N intake by 7.0 g day⁻¹ and when B diets were consumed, it was 0.7 g day⁻¹ less than N intake. Feed N degradability in the rumen and apparent N digestibility of S diets were lower (P < 0.05; P < 0.001) than those of B diets.

Rumen (P < 0.05) and total (P < 0.001) digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) was higher when S diets were given. The proportion of digestible fibre disappearing in the rumen was not affected by the diet. The rate and extent of silage and hay DM degradation were not significantly affected by the diet. However, dietary inclusion of molasses decreased (P < 0.05) the lag time of both hay and silage DM degradation.

The rumen dilution rate of liquid averaged 0.097 and that of particles, 0.049; neither was significantly different for either B and S diets or U and M diets. Duodenal liquid flow was higher (P < 0.05) for M diets.

Average rumen pH was not affected by the diet, but the molasses diets increased (P < 0.05) the range in rumen pH. The BM diet was associated with higher (P < 0.01) rumen ammonia concentration than the other diets. Low rumen ammonia concentrations (< 2 mM) were observed for long periods between feeds. The molar proportion of butyrate was higher on B diets and there was a trend towards a higher proportion of acetate and propionate on S diets. Molasses tended to increase the molar proportion of propionate and butyrate.     

Palm kernel meal as a feed for poultry. 4. Use of palm kernel meal by laying birds

In each of 2 experiments, 200 laying birds of the Harco strain were used to determine the effects of increasing amounts of dietary palm kernel meal (PKM) on egg production rate and egg quality. The results show that up to 40% of PKM can be included in diets for layers without any adverse effects on performance or egg quality. As the proportion of PKM increased beyond 40%, there was a significant drop in egg production (P < 0.05), egg weight (P < 0.01), feed intake (P < 0.01) and feed conversion efficiency (P < 0.01). The cost of feed required to produce 1 kg of eggs was reduced by feeding with PKM. Diets containing 50–70% of PKM caused the production of very watery faeces. It is recommended that the maximum level of inclusion of PKM in the diet of laying birds should be 40%.     

The utilization of canola and its constituents by lactating dairy cows

Three feeding trials and one nylon bag trial were conducted to determine the effect of supplementing a barley-based control diet with 3.5% canola oil (CO), 22% presscake (CPC) or 9% whole seed (WCS) on feed intake, digestibility, milk yield and composition of lactating dairy cows. Ruminal utilization of canola meal (CM), CPC and WCS was also determined. Increasing the level of fat in the diet had no significant effect on intake of concentrate or digestible energy, or on total tract digestibility of dry matter (DM), crude protein (CP) and acid detergent fibre. Addition of canola in the form of CPC and WCS gave greater energy and ether extract digestibility than C and CO (P < 0.05). Diet had no significant effect on milk production, yield of milk CP, milk lactose + ash, gross energetic efficiency of milk production, milk urea or minerals. Milk fat and 4% fat corrected milk (FCM) yield were similar with the C and CPC diets, and with the CO and WCS diets. But the CO and WCS diets gave less milk fat and FCM than the C diet (P < 0.05). Milk crude protein was higher (P < 0.05) on the WCS diet than on the C, CO and CPC diets, which were similar. Diets WCS, C and CO promoted similar levels of blood urea (BU) but BU levels with CPC and CO were lower than with the C diet (P < 0.05). Ruminal DM and CP disappearance of CM was lower than for WCS and CPC at all incubation times (P < 0.05).     

Role of dietary oleic acid from two different sources on fatty acid composition of erythrocyte membrane and blood pressure in healthy subjects

This study has been undertaken to determine the effect of a diet enriched with olive oil (OO) and high-oleic sunflower oil (HOSO) on fatty acid composition of erythrocyte membrane phospholipids and blood pressure in healthy women. OO and HOSO were used as natural sources of monounsaturated fatty acids (MUFAs) in a random-order sequence over two 4-week periods with a 4-week washout period between both MUFA diets. HOSO diet resulted in significant increases in oleic [(18:1n-9) 8.6%, P < 0.001], eicosenoic [(20:1n-9) 33.3%, P < 0.05], arachidonic [(20:4n-6) 6.2%, P < 0.05], and docosapentaenoic [(22:5n-6) 56.0%, P < 0.001] acids, whereas OO diet besides increased the content of stearic acid [(18:0) 13.6%, P < 0.01] and long-chain polyunsaturated fatty acids (PUFAs) of the n-3 family (22:5n-3 and 22:6n-3), when compared with the baseline [a diet high in saturated fatty acids (SFAs) and low in MUFAs]. In contrast, there was a significant decrease in linoleic acid [(18:2n-6) 21.8%, P < 0.001] for both MUFA diets. Consistent with these data, dietary intake of OO significantly raised total PUFAs (7.2%, P < 0.05), the n-3 fatty acids (22.2%, P < 0.01) and the PUFAs/SFAs ratio (9.3%, P < 0.01), as well as decreased the ratio of cholesterol to phospholipids (26,1%, P < 0.001) versus HOSO-based diet. Interestingly, dietary OO, but not HOSO, was able to significantly reduce the systolic (3%, P < 0.05) and diastolic (4%, P < 0.05) blood pressures. Although both vegetable oils provided a similar content of MUFAs (mainly oleic acid), our findings rather indicate that OO has important benefits to modulate the fatty acid composition of membranes and the mechanisms involved in the regulation of blood pressure in human.     

Feeding value of field beans (Vicia faba L. var. minor) with and without enzyme containing tannase,pectinase and xylanase activities for broilers

Effects of field beans with various tannin content and exogenous enzyme mixture containing tannase, pectinase and xylanase activities on N-corrected dietary apparent metabolisable energy (AMEn), coefficients of dry matter (DMR) and nitrogen retention (NR), fat digestibility, gastrointestinal tract (GIT) development, jejunal villus morphometry, ileal digesta viscosity and sialic acid were examined. Birds’ growth performance and energy conversion ratio (ECR) were also measured. Birds were fed one of eight mash diets. The Control diet contained as major ingredients wheat (400 g/kg) and soybean meal (SBM) (127 g/kg and 221 g crude protein/kg and 12.83 MJ AMEn/kg. To reduce nutrient density, the Control diet also contained washed sand at 119 g/kg. Another three diets containing 300 g/kg of each of three experimental field bean cultivar samples in replacement for SBM and sand were also mixed. Each diet was fed to nine pens with two male Ross 308 broilers. Diets high in tannin had low AMEn, ECR, DMR and NR (p < 0.001). Feeding field beans increased (p < 0.001) the weights of the pancreas and the proventriculus and gizzard (PG) of the birds. Supplementing diets with the enzyme mixture improved (p < 0.001) feed conversion efficiency, AMEn and all nutrient utilisation coefficients despite the tannins in diets. The enzyme mixture reduced ileal digesta viscosity (p < 0.001) and the weight of pancreas, total GIT and PG (p < 0.05) of the birds. It can be concluded that the feeding value of field beans with different tannin contents may vary when fed to broilers. The supplementation of the enzyme mixture improved the feeding value of diets for broilers. The beneficial effect of the addition of the enzyme mixture seems to be mediated through reduced ileal digesta viscosity and improved nutrient availability.     

Effect of thiamin deficiency on energy metabolites in the turkey

The effects of thiamin deficiency on selected energy-related metabolites was investigated. A basal diet (B) was formulated to be 11% of NRC recommended level of 2 mg/kg of thiamin. Thiamin was added to this basal diet to generate the control diet (C). Twenty one-week-old female turkeys were fed either the B or C diet. On days four and five of the experiment, food intake was decreased significantly in B fed turkeys (P < 0.05). Plasma and brain samples were collected at this time. Brains were dissected and analyzed for ATP, ADP, uric acid, free fatty acids, glucose, and GABA. Adenosine triphosphate and the ATP/ADP ratio were decreased in the hindbrain (medulla-pons area) of thiamin deficient birds (P < 0.01). Uric acid was increased (P < 0.001) and free fatty acids were decreased (P < 0.0005) in the plasma of thiamin deficient birds. Based on the data, changes in ATP and ATP/ADP levels may be related to the anorectic behavior exhibited by the thiamin deficient bird.     

Tissue fatty acid deposition is influenced by an interaction of dietary oil source and energy intake level in rats

To investigate the net tissue fatty acid deposition in response to graded levels of energy restriction and modification of diet fatty acid composition, rats were randomly assigned into four dietary groups and fed for 10 weeks diets containing 40% as energy of either fish, safflower, or olive oil, or beef tallow, consumed ad libitum or energy restricted to 85% or 68% of ad libitum intake by reducing diet carbohydrate content. An additional eight rats were killed before the diet regimen, to provide baseline data from which fatty acid deposition rates were calculated. Body weight, and heart, liver and fat mass gains were decreased with energy restriction (P<0.001). Olive oil feeding resulted in higher body weight gain (P < 0.03) than tallow feeding, whereas fish oil feeding was associated with highest (P < 0.007) liver weight and lowest (P < 0.03) fat mass gains. Energy deficit-related differences in the deposition of stearic, linoleic, arachidonic, and docosahexaenoic acids in heart and palmitic and docosahexaenoic acids in liver were dependent on the dietary oil consumed (P < 0.03). Similarly, interactive effects of restricted food intake and dietary oil type were found in the gain of palmitic, stearic, oleic, and linoleic acids in adipose tissue (P < 0.01) when expressed in relation to the amount of each fatty acid consumed. These data suggest that energy intake level can influence the deposition pattern, as well as oxidation rate, of tissue fatty acids as a function of tissue type, fatty acid structure, and dietary fatty acid composition.     

Sensory varieties in concentrate diets for stabled horses: effects on behaviour and selection

There is little published information about feeding behaviour of horses presented with concentrate diets and whether restricted variety affects foraging behaviour on concentrate diets is currently unclear. This study investigated the effects of sensory variety on diet selection and behaviour of stabled horses. In three replicated trials, four low energy concentrates were presented. In trial 1 formulation varied with no added flavourants, in trial 2 formulation and flavour varied, in trial 3 formulation was constant and flavour varied.

Up to eight horses were observed in two identical stables containing, either a single concentrate feed or four concentrate feeds (multiple concentrates) for 5 min. To control for palatability each concentrate was presented as the single concentrate twice within each trial. Trials were videotaped and 12 mutually exclusive behaviour patterns compared.

Significant differences (P < 0.05 − P < 0.001) in foraging and non-foraging behaviour were recorded between single and multiple sessions in trials 1, 2 and 3. In all trials the concentrate available in the single concentrate sessions was shown to influence diet selection during multiple sessions. In trial 3, four otherwise identical base diets flavoured with molasses, garlic, mint or herbs, tested whether manipulating flavour was sufficient to affect behaviour and diet selection. When multiple and single session behaviour was compared horse foraged more frequently (P < 0.005) and for longer (P < 0.05) in multiple sessions but foraging bouts were shorter (P < 0.05), suggesting natural patch foraging behaviour occurs in stabled horses offered multiple concentrate diets even if they vary only in flavour.     

Effects of β-glucanase supplementation of barley diets on growth performance of broilers

A trial was performed to examine the effects of levels of barley substitution and supplementation with β-glucanase in a corn-soybean diet on growth performance and intestinal characteristics of broiler chickens. The experiment involved five levels of barley substituted for corn (0, 125, 250, 500, and 1000 g/kg) and two levels of β-glucanase supplement (with 0.5 g/kg and without) in a factorial arrangement with two replicates. Four hundred day-old commercial strain Harber broiler chickens were randomly allocated into twenty groups of ten dietary treatments for a six-week feeding trial, growing (0-3 week) and finishing period (4-6 week). Unless supplemented with β-glucanase, broilers receiving the diet with more than 250 g/kg of the barley substitute gained slower during the growth period. Conversely, supplementing β-glucanase did not improve total weight gain (0-6 weeks) with a diet of 500 g/kg barley substitution. As the level of barley substitution increased, feed intake in the growing period decreased significantly and viscosity of the intestinal contents increased. However, such an increase did not significantly influence feed conversion (P > 0.05). Supplementation with β-glucanase on diet up to 250 g/kg of barley substitute not only enhanced body weight gains of growing broilers, but also improved the live-weight of six-week-old broilers (P < 0.05).     

Effects of Tasco (a seaweed extract) and heat stress on N metabolism and meat fatty acids in wether lambs fed hays containing endophyte-infected fescue

Wether lambs (n = 27, average BW = 40 kg) were used to test response to forage treated with Tasco-Forage (an extract of the brown kelp Ascophyllum nodosum) prior to conserving, or to direct feeding of the extract (Tasco-EX). Hays made from endophyte (Neoyphodium coenophialum)-infested tall fescue (Festuca arundinacea)-based pasture received 0 or 3 kg of Tasco/ha prior to harvest. Lambs, blocked by weight, were randomly allotted to three diets: (1) control hay, (2) treated hay, and (3) #1 + Tasco-EX fed at 1% of the diet. Hays were low in CP (<7%) so all lambs were fed soybean meal (12% of the diet) in addition to trace mineralized salt. Diets were fed at 1.5% BW to prevent refusals. Total collections (7 d) were made during periods without or with applied heat stress. After each period, rumen contents were obtained to determine pH, NH₃ and VFA. Lambs were sacrificed post-trial. A subset was used to evaluate sensory traits and muscle fatty acids. Lambs were in negative N balance during the study and Tasco treatments did not affect N metabolism. Fecal N tended (P < 0.10) to increase with short duration heat stress causing a concomitant decrease (P < 0.05) in apparent N digestibility (58.6 versus 56.1%; S.E. = 0.7). Urinary N loss decreased (P < 0.001) with heat stress (8.0 versus 5.9 g/d; S.E. = 0.2), resulting in increased (P < 0.001) N retention (−2.1 versus −0.3 g/d; S.E. = 0.2). Apparent OM digestibility was not affected by heat stress but was greater (P < 0.05) for lambs fed Tasco-EX treatment than those fed treated hay. Treatment diets decreased (P < 0.05) ruminal butyrate. Heat stress increased (P < 0.05) acetate and total VFA and decreased (P < 0.01) ruminal pH. A tendency (P < 0.11) of increased 14:1ω5, decreased (P < 0.05) 18:0 and total saturated fatty acids in muscle was observed with Tasco diets. Meat sensory characteristics were not affected by treatment. Tasco may alter some aspects of rumen or lipid metabolism but has no effect on N metabolism or meat sensory characteristics of sheep fed restricted, low-quality diets.     

Effects of ensiled forage legumes on performance of store finishing lambs

Male Beulah speckled face lambs (initial live weight (LW) 28.8 ± 0.31 kg) were allocated to three dietary treatments to evaluate the performance of store lambs of a hill breed when offered ensiled lucerne (Medicago sativa), red clover (Trifolium pratense) or ryegrass. Second-cut silage bales (wilted and inoculated) were prepared from 3-year old lucerne and red clover stands and a 1-year old ryegrass sward. All the lambs were group-housed and offered ad libitum ryegrass silage during a 3-week co-variate period. This was followed by a week of dietary changeover period, after which the lambs were housed individually and offered their treatment diet ad libitum. All the lambs received a flat rate supplement of pelleted molassed sugarbeet (250 g fresh weight/day). Individual intakes were determined daily, and weekly measurements of LW and body condition score (CS) were made. Additional measurements were taken by scanning the lambs for depth of Longissimus dorsi (LD) muscle and subcutaneous fat. Over an experimental period of 7 weeks, the lambs offered red clover silage had a higher voluntary silage dry matter (DM) intake, total DM intake and metabolisable energy (ME) intake (P < 0.001) than lambs offered either lucerne or ryegrass silage. This resulted in a faster (P < 0.001) growth rate and increase (P < 0.001) in CS, with no difference between lucerne and ryegrass silages. The feed conversion efficiency (FCE) was 8.0 ± 0.61 kg feed/kg gain for lambs fed red clover silage, compared with 16.6 ± 2.82 and 10.6 ± 1.94 kg feed/kg gain for lucerne and ryegrass silage, respectively. The CP intake was higher (P < 0.001) for lambs fed the lucerne and red clover silages than for the ryegrass silage treatment. The concentration of plasma total protein (TP) was higher (P < 0.05) for lambs offered ryegrass silage versus lucerne and red clover silage. Urea concentrations were highest for lambs fed lucerne silage and lowest for those fed ryegrass silage (P < 0.05). The glucose concentration was higher (P < 0.05) for lambs offered red clover silage, whereas non-esterified fatty acids (NEFA) concentration was higher (P < 0.05) for lambs offered lucerne silage. Substituting ryegrass silage with red clover silage has the potential to improve the performance of finishing store lambs.     

Productive performance of broiler chicks fed diets containing irradiated meat-bone meal

Experiments were carried out to study the changes in the values of feed efficiency (FE), total protein efficiency (TPE) and metabolizable energy efficiency (MEE) of broiler chicks fed during four age periods (14–21, 21–28, 28–35 and 35–42 days). Five experimental diets were similar in composition but different in the irradiation dose (0, 5, 10, 25 or 50 kGy) applied to the meat–bone meal content of each diet. The results indicated that feeding of broiler chicks on irradiated meat–bone meal (5–50 kGy) had no significant (P>0.05) effects on FE, TPE, MEE and body weight gain during the four experimental age periods. The average values of the FE (feed consumption/weight gain), TPE (weight gain/total protein consumption) and MEE (metabolizable energy consumption in MJ/kg gain) were 1.96, 2.59 and 23.13, respectively. The values of FE and MEE increased while TPE decreased significantly (P<0.05) with age. The pooled FE value was 1.60 during the 14–21 days of age and increased to 2.66 from 35–42 days of age. However, the TPE value was 3.01 during the 14–21-day age period and decreased to 1.82 over the 35–42-day age period. The energy consumption value to produce one kg of body weight increased during the 35–42-day period by 7.71–12.72 MJ/kg gain in comparison with that from the other experimental age periods. Weight gain rate decreased significantly (P<0.05) during the 35–42-day period (66 g/week/bird) when compared with the rate observed during the 14 through 35-day age period.     

Fattening Pelibuey lambs with sugar cane tops and corn complemented with or without slow intake urea supplement

One hundred and eighty Pelibuey lambs were fattened for 120 days with three treatments evaluating in situ DM disappearance, voluntary DM or OM intake, rumen degradation, rate of passage, NH₃ and VFA concentration, apparent digestibility, ruminal pH, total fermentable carbohydrates and weight gains. The first diet (T1), 60 lambs (25.7 ± 0.7 kg BW) plus two cannulated sheep were fed 100% sugar cane tops (SCT) per day; treatment 2 (T2), 60 lambs (25.4 ± 0.4 kg BW) plus two cannulated sheep diet was SCT supplemented with 200 g DM of slow intake urea supplement (SIUS) (a 4% urea mixture) per day. Treatment 3 (T3), 60 sheep (25.5 + 0.5 kg BW) plus two cannulated animals, fed SCT and corn crop chopped (C) mixture (40:60%) were supplemented with 200 g SIUS per day. Ruminal kinetics were determined thereafter in four adult ruminal cannulated sheep in metabolic cages. A 100% corn diet was added to the second trial (T4). At all times, fibrous forages were available and exceeded VDMI. Daily BW gain by SCT animals was 70 g/d compared to 135 g/d for SCT/SIUS and 218 g/d for SCT/C/SIUS diets (P < 0.05). Total forage intake was similar for T1 and T2 treatments and higher for T3 (P < 0.05). Kinetics observation showed a total DMI variation increasing from 474 g/d for T1; 597 g/d for T4 to 797 g/d for T2, and 917 g/d for T3, being different for the last two treatments compared with the first two (P < 0.001) and similar among SIUS diets. Rumen pH diminished from 6.8 to 6.7 at 2 h, when SIUS was offered, and stayed above 6.5 during the 12 h of sampling when SIUS was the only supplement and 6.3 when corn was added, while in SCT lambs, ruminal pH decreased to 6.2 by 6 h and rose again to 6.4 after 12 h favoring bacterial multiplication. Ammonia concentration and digestion of potential digestible and indigestible fractions were significantly augmented (P < 0.05) by SIUS. In vivo nitrogen digestibility was different (P < 0.05) among diets: T1, T2, T3, and T4 (36.5%, 74.1%, 76.5%, and 39.4%, respectively). In vivo digestibility of DM, OM, cellulose and hemicellulose was similar among T2 and T3 groups but different when T1 or T4 diets were offered (P < 0.05). NDF digestibility was higher for T3 (77.1%) and T2 (75.1%) but different from T1 (57.1%) and T4 (59.1%) (P < 0.01). In situ DM disappearance did not show differences among T2 and T3 diets at 9, 12, 24 and 48 h of incubation but differed in percentage for T1 and T4. Digestion rate constant (k_d) was similar among SIUS diets 0.038 and 0.039, but different from T1 and T4 diets 0.023; 0.021 (P < 0.05). True digestibility of NDF was higher (P < 0.05) in SCT/SIUS/C (32.5%) and SCT/SIUS (32.7%) compared with SCT (26.2%) and C (27.4%). Passage of NDF was different (P < 0.05) between T1 (0.059 h⁻¹) and T4 (0.061 h⁻¹) from 0.079 (T2) and 0.081 k_p/h (T3). The half-time (t_1/2) disappearance for hemicellulose was higher (P < 0.05) for SCT/SIUS (22.1 h) and SCT/SIUS/C (29.2 h) as compared to SCT (18.1 h). Kinetic performance among SCT and C diet did not have a statistical difference. Utilization of fibrous forages by lambs was higher (P < 0.05) for SIUS diets. VDMI and apparent digestibility showed better performance for DM and OM, lower acetate molar proportions and greater feed intake by both SIUS diets which was reflected in body weight gain.     

Nitrogen metabolism and blood metabolites in three goat breeds fed increasing amounts of protein

Twelve wethers (27–33 kg and 12–14 months of age) representing meat (Nubian), milk (Alpine) and mohair (Angora) producing goats were used to evaluate breed differences in protein utilization with diets containing 9 (L), 15(M) or 21% CP (H) and 2.4 Mcal ME/kg DM in a digestion trial. Fecal N, urine N and absorbed N as percent of N intake were not affected (P>0.05) by breed. Retained N as percent of absorbed N was not different (P>0.05) between breeds. Ruminal propionate (molar %) was lower (P<0.05) in Angora, but other ruminal VFA and ammonia-N were not affected (P>0.05) by diet or breed. Plasma urea-N increased (P<0.01) with dietary CP level (8.3, 22.0 and 33.3 mg/dl for L, M and H, respectively), and concentrations were lowest for Angoras and highest for Nubians (18.5 vs. 21.2 vs. 23.9 mg/dl) (P<0.01). Plasma total protein (mean 69.7 g/l), glucose (mean 83.1 mg/dl), non-esterfied fatty acids (mean 101.4 μEq/l) and cortisol (mean 10.8 ng/ml) were not affected (P>0.05) by breed or diet. Plasma glucagon concentrations increased (P<0.05) with increasing CP intake (72.4, 167.6 and 239.1 pg/ml for L, M and H, respectively). The study indicated that there was no apparent breed difference between Nubian, Alpine and Angora goats in nitrogen utilization when goats were fed pelleted diets containing 9 to 21% CP.     

Apparent protein digestibility and recovery of endogenous nitrogen at the terminal ileum of pigs fed diets containing various soyabean products, peas or rapeseed hulls

Effects of the use of three different soyabean products (soya concentrate and two different soyabean meals), peas or rapeseed hulls in the diet on the apparent ileal digestibility of CP (N × 6.25) and recovery of ileal endogenous nitrogen (N) in weanling pigs were investigated. Ileal endogenous N was measured using the ¹⁵N-isotope dilution method. Thirteen castrated male pigs (BW of 12–23 kg) were fed maize starch-based diets containing either soya concentrate (SC), purified rapeseed hulls (pRH) and SC (SRH diet), soyabean meal (SBM), a mixture of toasted and untoasted soyabean meal (mSBM) or peas. The apparent ileal digestibility (AID) of dry matter (DM) for the SC, SRH, SBM, mSBM and pea diets was 82.1, 74.3, 83.3, 80.0 and 74.9% (P < 0.05), respectively. The AID of CP for these diets was 82.4, 67.6, 81.6, 68.0 and 76.9% (P < 0.05), respectively. Similar differences in the AID for amino acids (AA) in the diets were found. The AID for CP and for the sum of AA in the pRH, as calculated by the difference between the SC and SRH diet, were 26 and 41%, respectively. For the SC, SRH, SBM, mSBM and pea diet, ileal recovery (g/kg of DM intake) for endogenous N were 2.79, 3.46, 2.73, 4.89 and 3.29 (P < 0.05), respectively, and for dietary N 1.16, 4.11, 1.64, 4.15 and 2.53 (P < 0.05), respectively. For the SC, SBM and mSBM diets, differences in AID of CP and AA were associated with differences in both the ileal recovery of endogenous N and the recovery of undigested dietary N. Differences in trypsin inhibitor activity (TIA) of the soya products were likely associated with these observations. It was also concluded that fibre (Neutral Detergent Fibre; NDF) in pea could be at least in part responsible for the relatively low AID of CP and AA and the high recovery of ileal endogenous N in the pea diet. The low AID of CP and AA of pRH was likely related to the association of protein to the fibre matrix in the fibre-rich rapeseed hulls.     

Effects of providing dietary wood (oak) charcoal to broiler chicks and laying hens

Three experiments were carried out to determine whether dietary wood (oak) charcoal applied during entire or phase feeding period would affect growth performance, abdominal fat weight, carcass weight, carcass yield, carcass composition and nutrient excretion of broilers and to determine whether dietary wood charcoal supplementation would affect laying performance and egg quality of laying hens. In the first experiment, different inclusion levels (0, 25, 50 and 100 g/kg feed) of wood charcoal in the diet were examined for a 6-week-period using broiler chicks of initial age 1 week. Dietary wood charcoal significantly increased feed intake (P<0.001), body weight gain (P<0.001) and improved feed conversion ratio (P<0.05) up to 28 days of age. However, at 49 days of age, charcoal inclusion did not significantly (P>0.05) affect body weight gain, feed intake, carcass weight and carcass yield, but increased (P<0.05) feed conversion ratio, carcass ash content, fat excretion, while reducing (P<0.05) mineral excretion in a dose dependent manner. In the second experiment, a phase application of dietary wood charcoal for a 6-week-period broiler chicks of initial age 1 week was assessed. During the first 28 days of age wood charcoal improved feed conversion ratio significantly (P<0.05). At 49 days of age, the groups receiving charcoal in the starter and/or finisher diets showed significantly (P<0.05) higher body weight gain and carcass weight than the control group receiving no charcoal. In the third experiment, different levels (0, 10, 20 and 40 g/kg feed) of wood charcoal supplementation to a layer diet were examined for a 7-week-period using laying hens of initial age 34 weeks. Dietary charcoal supplementation did not have a significant effect on any parameters related to performance and egg quality, but significantly reduced number of cracked eggs and the reduction was dose dependent (P<0.01). These data demonstrate that wood charcoal inclusion to the diet could be of value in improving broiler performance during the first 28 days of fattening period. In later ages, the positive effects of wood charcoal are limited. However, in laying hens dietary supplementation of wood charcoal reduces number of cracked eggs.     

Does the effect of pelleting depend on the wheat sample when fed to chickens?

Experimental comparisons of the nutritional value of different wheat cultivars commonly use feeds in meal form even though the large-scale broiler producers use steam pelleted feeds. The aim of this experiment was to examine the effect of steam pelleting on the performance, dietary N-corrected apparent metabolisable energy (AMEn), total tract dry matter retention (DMR), nitrogen retention (NR) and fat digestibility (FD) coefficients, and digestive tract development of broilers fed four different wheat samples in complete diets. Four European wheat samples, with different chemical composition and endosperm characteristics, were used in a broiler experiment. The wheat samples were milled through a 5 mm screen and four basal feeds containing 670 g/kg of each selected wheat sample were mixed. The basal feeds were then split into two batches and one of them was steam pelleted resulting in eight experimental diets. Each diet was fed ad libitum to eight pens of two male Ross 308 broilers from 10 to 24 days of age. Feeding pelleted diets improved (P<0.001) feed intake and weight gain, and daily water intake of the birds. Pelleting also improved dietary AMEn and FD (P<0.001) and DMR (P<0.05). An interaction (P<0.05) was observed between wheat samples and steam pelleting for NR. Steam pelleting improved (P<0.05) NR in the wheat sample with high starch and protein and hard endosperm but not in the rest of the wheat samples. Similar interactions (P<0.05) were also observed between wheat sample and steam pelleting for gain to feed (G : F) and water to feed (W : F) ratios. Pelleting improved G : F ratio the greatest in the wheat sample with high starch and protein and hard endosperm. Feeding the same wheat sample also decreased (P<0.05) W : F but only in the mash diets. Regardless of the wheat sample the values of dietary AMEn did not differ (P>0.05). Feeding different wheat types and pelleting did not (P>0.05) change the development of the gastrointestinal tract of the birds. The study showed that there were differences between four wheat samples when they were fed in pelleted complete feed, but no differences were observed when fed in mash form complete diets. Research on the interaction between pelleting and wheat chemical and quality characteristics is warranted.     

Sucking behaviour of dairy calves fed milk ad libitum by bucket or teat

The milk intake and sucking behaviour of Dutch and Holstein-Friesian crossbred calves fed milk replacer ad libitum by either the bucket method (n=8) or an artificial teat (n=6) were compared. The animals were observed for 3 weeks from the age of 2 weeks, penned individually and all provided with a “dummy” (artificial) teat near the milk source within the pen.

The teat-fed calves ingested significantly more milk than the bucket-fed calves (11.9 vs. 8.0 kg/day; P<0.05), and this intake took much longer (44.2 vs. 17.7 min/day; P<0.05). In both treatment groups, milk intake was organized in “meals”. The meal criterion, separating the withinmeal and between-meal non-feeding intervals, was set at 5 min. Frequency of meals and daily total meal duration did not differ significantly. Meals occurred rather randomly throughout a 24-h period.

On average, the dummy teat was used for 13 min per day by bucket-fed calves, but for only 1 min by teat-fed calves (P<0.05). Sucking of the dummy teat was largely clustered within the meal periods.

It is concluded that in the young calf a need for sucking exists independently of milk satiation. However, the level of satiation depends on whether the calf drinks or sucks the milk. Nutritive sucking is clearly more reinforcing than non-nutritive sucking.     

Effects of ileal endogenous nitrogen losses and dietary amino acid supplementation on nitrogen retention in growing pigs

The relationship between ileal endogenous nitrogen (N) losses and N retention was studied in two experiments with growing pigs of 40 to 60 kg. In Experiment 1, 13 ileal cannulated castrated males were fed diets based on maize starch, containing either soyabean meal (SBM) with a low trypsin inhibitor activity (TIA), a mixture of toasted and untoasted soyabean meal with a high TIA (mSBM), a commercial batch of peas, or rapeseed expeller cake (RC). Ileal endogenous N recovery was measured using the ¹⁵N-isotope dilution technique. Apparent ileal digestibility of crude protein (CP) for the SBM, mSBM, pea and RC diets were 82.8, 72.0, 76.7 and 68.7% (P < 0.05). True ileal CP digestibility for the diets was 96.5, 93.0, 94.0 and 87.5% (P < 0.05), and the recovery of ileal endogenous N was 3.08, 6.01, 4.55 and 5.36 g/kg DMI (P < 0.05). In Experiment 2, sixteen castrated males were used to determine N retention, using almost similar diets as in Experiment 1. The diets contained either SBM, mSBM or peas and were balanced for the contents of apparent ileal digestible (ID) CP (96 g/kg) and ID essential amino acids (EAA; at least 85% of requirement values). The fourth treatment was a diet with mSBM as protein source, but supplemented with EAA to the level of 95% of the requirement values (diet mSBMs). Apparent faecal CP digestibility for the SBM, mSBM, pea and mSBMs diets was 88.6, 87.2, 86.1 and 86.0% (P < 0.05). Urinary N excretion and N retention for these treatments were 0.39, 0.59, 0.40, 0.53 (P < 0.05) and 0.87, 0.80, 0.85, 0.84 g/kg^0.75/day (P < 0.05), respectively. Utilization of dietary ID N for N retention were 79.8, 73.3, 78.2 and 77.6% (P < 0.05), respectively. The study showed that increased ileal endogenous N losses are associated with higher losses of urinary N and with a lower N retention. Supplementation of extra essential AA to a diet causing a relatively high flow of ileal endogenous N, may compensate for the lower N utilization under these conditions, and thus limit effects on N retention.     

Influences of fallow age and season on the foraging behavior and diet selection pattern of goats (Capra hircus L.)

A study was undertaken to determine the foraging behavior and diet selection pattern of goats maintained on communal exclosures in relation to the influence of fallow age (years since effective protection initiated; <8 years vs. >12 years) and season (long rainy, dry, and short rainy seasons). The frequency of browsing was higher (P < 0.05) in the exclosures fallowed for >12 years compared to those fallowed for <8 years and this frequency was also highest during the short rainy season. More (P < 0.05) herbaceous bites were recorded in the <8 years fallow exclosures, compared to the >12 years fallow exclosures. Herbaceous species bites were maximized during the long rainy season whereas woody species bites were maximized during the dry season. The goats foraged upon 48 plant species of which 69% were woody species, 19% grasses, and the rest comprised of various forb species. The top species that significantly (P < 0.05) contributed to the diet of goats were Acacia etbaica, Balanites aegyptica, Cadaba farinosa, Capparis tomentosa, Dichrostachys cinerea, and Ocimum forskolei. The goats targeted taller woody species than the average of the exclosures. Maurea angolensis, Jasminium abyssinicum, C. farinosa, and Ormocarpum pubescence were among the preferred species that appeared to be on the verge of disappearance in most of the exclosures investigated in this study and require immediate attention. Using goats to reduce the threat of potential bush infestation appears to be a viable option for managing and sustaining production from exclosures since the goats showed preference for D. cinerea, the species considered a prolific invader plant. There is, however, a need to conduct further research on the impacts of direct browsing by the goats and this should also entail the determination of optimum number of goats/unit area.