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.     

Effect of feeding tree leaves as supplements on the nutrient digestion and rumen fermentation pattern in sheep grazing on semi-arid range of India – I

A study was carried out to determine the effect of feeding different tree leaves as supplements on nutrient digestion, rumen fermentation and blood parameters of sheep grazing on a semi-arid rangeland. Thirty adult Malpura rams of uniform body weight (39.0 ± 0.75) were divided into five groups of six each. They were grazed as a single flock from 08.00 to 17.00 h on a semi-arid rangeland. After the end of the grazing period, the first group (G1), which was not provided with any supplementation, served as the control. The second group (G2) was supplemented with 200 g of a concentrate mixture per head per day, whereas the third, fourth and fifth groups (G3–G5) were provided with approximately 200 g DM d⁻¹ of freshly cut foliage from Prosopis cineraria, Acacia nilotica and Albezia lebbek. The foliage from P. cineraria contained 133.4 g kg⁻¹ DM condensed tannin (CT) with protein precipitating capacity (PPC) of 66 g kg⁻¹ DM, whereas A. nilotica contained 18.9 g kg⁻¹ DM hydrolysable tannin (HT) with PPC of 11.5 g kg⁻¹ DM. However, A. lebbek did not contain any tannin. The protein contents were 119, 139 and 194 g kg⁻¹ DM, respectively. The DMI (g d⁻¹) was 688, 916, 1024, 1003, 999 in G1, G2, G3, G4 and G5, respectively. Digestible crude protein (DCP) and metabolizable energy (ME) intakes in supplemented groups G2–G5 were higher (P < 0.05) than in the control (G1). Supplementation improved the DM digestibility in all groups, whereas CP digestibility was lower (P < 0.05) in G3 compared to G2, G4 and G5. Rumen fermentation study conducted 6 h after supplementation revealed that total N, ammonia N, and total VFA levels were lower (P < 0.05) in G3 compared to the other supplemented groups. Although the haemoglobin (Hb) levels were similar among groups, blood urea N (BUN) was lowest in G3 compared to the other groups. The initial body weights were similar among groups (mean 39 kg). After 60 days of experimental feeding, all groups maintained their body weight, except the control group (G1), which lost body weight. It was observed, that supplementation with tree leaves containing CT like P. cineraria helps in better rumen fermentation pattern by preventing excessive loss of nitrogen. It was concluded that maximum nutritional benefits of tree leaves could be harvested, if used as supplement rather than as a sole feed.     

Effects of inclusion with blue lupins (Lupinus angustifolius) in broiler diets and enzyme supplementation on production performance, digestibility and dietary AME content

An experiment with broiler chickens was conducted to study the effect of inclusion of blue lupins and exogenous enzyme to broiler diets on the apparent metabolisable energy (AME), digestibility and performance. Two basal diets were formulated: a non-lupin diet A based on soya bean meal and maize, and a diet B where parts of soya bean meal and maize were substituted with blue lupin (200 g/kg). The two basal diets were fed either alone or, for diet B in combination with different enzyme preparations (Bio-Feed Plus, lactase, two galactanases (Gal-I and Gal-II)). The experiment was performed in battery cages with 648 male broiler chickens, where eight experimental diets were fed to the chickens from 7 to 21 days of age and weight gain and feed intake were measured during the period. At the end of the experiment, three chickens from each pen were slaughtered and the content from jejunum and ileum was separately collected and pooled and used for measurement on intestinal viscosity. For measurements of the apparent metabolisable energy and the apparent digestibility, excreta were collected at 22–24 days of age and ileal contents collected at 25–26 days from the remaining chickens.

Substitution of soya bean meal and maize with blue lupin depressed weight gain (9%) and feed conversion ratio (12%) significantly. Feed intake of the lupin-based diets was not decreased. The protein in lupin was digested to the same extent as the protein from soya bean meal, the coefficient of ileal apparent digestibility being on average 0.75. However, the high content of the non-starch polysaccharides (NSP; 450 g/kg) in lupin depressed the apparent digestibility of the organic matter by approximately 10%. The AME_n of the non-lupin diet was 14.01 MJ/kg dry matter (DM) compared to a value of 13.11 MJ/kg DM in the lupin control diet. Improvements in the measured parameters were seen with some of the enzymes. Gal-I, and Gal-II in combination with lactase were the most efficient enzymes concerning improvement in AME_n and performance. Weight gain was increased by 3.5–5.5% by addition with these enzymes. Gal-I increased the AME_n significantly to 13.65 MJ/kg, a value not significantly different from the AME_n of the non-lupin diet. There was no effect of addition with the different enzymes on the coefficients of apparent digestibility of organic matter measured in the ileum, whereas addition with Gal-I to the lupin diet increased the apparent digestibility of organic matter over the total tract by 3%. The mode of action of the galactanases has been to hydrolyse the galactan in the NSP cell wall of lupins to galactose and dimers of galactose, which are energy-yielding to poultry. From the results obtained, it can be indicated that Gal-I increased the energy utilisation of the lupin-based diet, confirmed by the improved AME_n content and performance.     

The effect of feeding expeller-pressed canola meal on growth performance and diet nutrient digestibility in weaned pigs

The effects of feeding increasing levels of expeller-pressed (EP) canola meal in substitution for soybean meal as an energy and amino acid source were evaluated in 240 weaned pigs with an initial body weight of 7.3 ± 0.6 kg. Five pelleted wheat-based diets containing 0, 50, 100, 150 or 200 g EP canola meal/kg were formulated to contain 10.0 MJ net energy (NE)/kg and 1.18 g standardised ileal digestible (SID) lysine/MJ NE and were fed for 4 wk starting 1 wk after weaning at 19 days of age. Expeller-pressed canola meal was added at the expense of soybean meal and the diets were balanced for NE using canola oil and for amino acids using crystalline lysine, methionine, threonine and tryptophan. Increasing inclusion of EP canola meal linearly reduced (P<0.001) the apparent total tract digestibility of energy, dry matter and crude protein and the digestible energy content of diets. From 0 to 28 days on trial, increasing inclusion of EP canola meal did not affect body weight gain, feed intake and feed efficiency. In conclusion, up to 200 g EP canola meal/kg can replace soybean meal in diets formulated to equal NE and SID amino acid content and fed to nursery pigs starting 1 wk after weaning without reducing growth performance.     

Genetic selection, sex and feeding treatment affect the whole-body chemical composition of sheep

Hypotheses on total body chemical composition were tested using data from 350 Suffolk sheep grown to a wide range of live weights, and fed in a non-limiting way, or with reduced amounts of feed, or ad libitum on feeds of reduced protein content. The sheep were from an experiment where selection used an index designed to increase the lean deposition rate while restricting the fat deposition rate. Ultrasound muscle and fat depths were the only composition measurements in the index. The animals were males and females from a selection (S) line and its unselected control (C). The protein content of the lipid-free dry matter was unaffected by live weight, sex or feeding treatment with only a very small effect of genetic line (0.762 kg/kg in S and 0.753 kg/kg in C; P < 0.05). The form of the relationship between water and protein was not affected by any of the factors; in the different kinds of sheep it was consistent with no effect other than through differences in mature protein weight. The water : protein ratio at maturity was estimated as 3.45. Over the whole dataset, lipid weight (L) increased with protein weight (P) according to L = 0.3135 × P1.850. Allowing for this scaling, fatness increased on low-protein feeds, was greater in females than in males and in C than in S (P < 0.001). Lipid content (g/kg fleece-free empty body weight) was reduced by restricted feeding only in males at the highest slaughter weight (114 kg). The lines differed in lipid content (P < 0.001) with means of 265.1 g/kg for C and 237.3 g/kg for S. Importantly, there was no interaction between line and feeding treatments. A higher proportion of total body protein was in the carcass in S than in C (0.627 v. 0.610; P < 0.001). For lipid, the difference was reversed (0.736 v. 0.744; P < 0.05). The total energy content increased quadratically with slaughter weight. At a particular weight, the energy content of gain was higher in females than in males and in C than in S. Genetic selection affected body composition at a weight favouring the distribution of protein to the carcass and lipid to the non-carcass. Once allowing for effects of genetic selection, sex and feeding treatment on fatness, simple rules can be used to generate the chemical composition of sheep.     

Effects of dietary amino acid l‐lysine on survival,growth and haemato‐biochemical parameters in Indian catfish,Heteropneustes fossilis (Bloch, 1974), fingerlings

An 8‐week feeding experiment was conducted to estimate the dietary lysine requirement of fingerling Indian catfish, Heteropneustes fossilis (total length = 6.35 ± 1.10 cm; weight = 4.70 ± 0.65 g) by feeding six isonitrogenous (400 g/kg CP) and isocaloric diets (17.90 kJ/g) containing six supplemental lysine levels ranging from 11.0 to 23.5 g/kg (diets I to VI, in incremental steps of 2.5 g/kg). Triplicate groups with 20 fish each were stocked in 75‐L circular continuous flow‐through troughs and fed experimental diets at 4% BW/day twice daily (08:00 and 18:00 h). Maximum live weight gain (304%), best‐feed conversion ratio (FCR, 1.46) and protein efficiency ratio (PER, 1.71) were obtained at 18.5 g/kg dietary lysine, beyond which these values showed a slight declining tendency. Best values for somatic and hematological indices were also obtained at this level. Significantly (p < .05) higher body protein and low carcass moisture and intermediate fat contents were noted in fish fed diets containing 18.5 g/kg lysine. The quadratic regression analyses of live weight gain, FCR, PER and body protein deposition (BPD) data indicated lysine requirements at 19.3, 18.8, 18.6 and 18.6 g/kg of dry diet, respectively. Based on these results, it is recommended that the H. fossilis diet should contain lysine at a level of 19.0 g/kg of dry diet, corresponding to 47.5 g/kg of dietary protein, for optimum growth and efficient feed utilization.     

The interaction between lactose level and enzyme supplementation and form of barley processing on performance, digestibility and faecal volatile fatty acid concentration of weanling pigs fed barley-based diets

A 2×3 factorial arrangement was used to investigate the interaction between lactose level (170 g/kg versus 275 g/kg), enzyme supplementation (with or without endo-1,3 (4)-β-glucanase) and toasting (raw barley versus toasted barley) in barley-based diets (250 g/kg) on piglet performance and diet digestibility postweaning. One hundred and forty-four weaned piglets (24 days old, 6.5 kg live weight) were blocked on the basis of live weight and were assigned to one of six dietary treatments (n = 6) for 21 days as follows: (1) 170 g lactose/kg and barley (250 g/kg), (2) 275 g lactose/kg and barley (250 g/kg), (3) 170 g lactose/kg and toasted-flaked barley (250 g/kg), (4) 275 g lactose/kg and toasted-flaked barley (250 g/kg), (5) 170 g lactose/kg and barley (250 g/kg) plus β-glucanase, (6) 275 g lactose/kg and barley (250 g/kg) plus β-glucanase. There was an interaction (P<0.05) between lactose level and β-glucanase supplementation on average daily gain (ADG), food conversion ratio (FCR) and coefficient of total tract apparent digestibilities (CTTAD) of dry matter (DMD), organic matter (OMD) and nitrogen (N). Pigs offered 170 g lactose/kg and β-glucanase supplementation had an improved FCR and ADG compared to the treatment based on 170 g lactose/kg and unsupplemented barley. However, β-glucanase supplementation at 275 g lactose/kg had no significant effect on FCR and ADG compared to the 275 g lactose/kg and unsupplemented barley. Pigs offered diets containing 170 g lactose/kg plus β-glucanase had a significantly higher CTTAD for DMD, OMD and nitrogen compared to the 275 g lactose/kg plus β-glucanase diet. However, there was no significant effect of lactose level in the unsupplemented diets. Pigs offered high lactose diets showed significantly increased total VFA concentration, molar proportions of butyric acid and reduced acetic acid compared to those offered low lactose diets. Pigs offered β-glucanase supplemented diets showed reduced (P<0.05) total VFA concentration compared to unsupplemented diets. In conclusion, β-glucanase supplementation improved diet digestibility and pig performance compared to the unsupplemented diet at the low lactose level only. There was no response of β-glucanase supplementation at the high level of lactose.     

Dried sugar beet pulp as a high energy feed for beef cattle

Digestibility trials with 8 lots of pelleted dried sugar beet pulp, carried out with wethers, demonstrated that dried sugar beet pulp is a highly digestible energy source for ruminants. From the digestion coefficients obtained, and a value number of 95, the starch equivalent of the dry matter of dried sugar beet pulp was calculated to be 73.3, while the net energy expressed in EF_r was 619 EF_r per kg dry matter. This is about 90% of the net energy content of barley containing 4% crude fibre in the dry matter.Beef production trials were carried out with 702 young bulls fed on complete dry rations based on dried sugar beet pulp. Two categories of animals were used: 322 baby-beef bulls (intensive system) slaughtered at 13 months of age at an average live-weight of 480 kg; and 380 young bulls coming from pasture (semi-intensive system) at about 250 kg live-weight, and fattened indoors up to at least 550 kg live-weight. With each category, three different rations have been studied. These contained respectively, 50, 60 or 70% pelleted dried sugar beet pulp; the remainder of the rations consisted of respectively 50, 40 or 30% concentrates. The diets were fed ad libitum; straw and water were always available. The three complete dry rations proved to be equally successful for intensive beef production. The carcass quality was good for all animals. The average daily gain obtained with the baby-beef bulls for the three rations respectively was 1 207 g, 1 274 g and 1 172 g; for the second category of bulls the mean growth rates were generally slightly higher: 1 281 g, 1 309 g and 1 357 g.The feed efficiency was higher with the younger animals: the baby-beef bulls (live-weight interval: 150–480 kg) consumed about 2.5 kg protein supplement and 3.5 kg dried sugar beet pulp per kg live-weight gain; while the intake per kg live-weight gain with the bulls of the second category (live-weight interval: 250–560 kg) amounted approximately to 2.75 kg protein supplement and 4 kg dried sugar beet pulp. Within each category of bulls, the feed cost per kg live-weight gain decreased with increasing amounts of dried sugar beet pulp in the rations.     

Evaluation of lamb performance and costs in motherless rearing of German Grey Heath sheep under field conditions using automatic feeding systems

Performance and costs were evaluated for 205 German Grey Heath lambs reared artificially under field conditions using three feeding and three weaning regimes. In phase 1 (pre-weaning), ad libitum feeding of milk replacer (MR) on an automatic lamb feeder was compared to restricted MR feeding on the modified calf feeder “Stand alone II^®” or with buckets. In phase 2 (after weaning at 12 kg body weight), abrupt weaning was compared to gradual weaning systems with reduction of the amount or the concentration of MR over 2 weeks. In phase 1, average daily gains (ADG) were highest in the Ad libitum group (0.262 ± 0.032 kg/d), followed by Bucket and Stand alone with 0.227 ± 0.036 kg/d and 0.209 ± 0.023 kg/d, respectively (P < 0.05). In contrast, feed conversion rate was best for group Stand alone (1.17:1), compared to 1.20:1 in group Bucket and 1.23:1 in group Ad libitum. In phase 2, abrupt weaning caused weight loss in lambs from the Ad libitum and Bucket groups, but not in group Stand alone. No post-weaning growth check was seen in lambs weaned gradually. In general, differences in body weight (BW) between groups were low, and on d 70, no significant difference was seen between feeding groups, whereas lambs weaned abruptly still had lower BW than lambs weaned by reducing the amount of MR (P < 0.05). Total lamb mortality was 3.9%, with no accumulation of infectious disease in any of the feeding or weaning groups. Economic analysis revealed that total costs in phase 1 were highest for group Stand alone (57–70 € per lamb), followed by the Bucket group (63 € per lamb). Although MR consumption was higher in the Ad libitum group, this method was the most cost-efficient (50–54 € per lamb), because purchase price of the feeder and labor costs were relatively low. In phase 2, gradual weaning systems added costs of 4.70–9.50 € per lamb. Our findings indicate that the most efficient way to rear 60–120 lambs artificially under field conditions is by using an automatic ad libitum lamb feeder followed by abrupt weaning.     

Effect of tree leaf as supplementation on nutrient digestion and rumen fermentation pattern in sheep grazing semi-arid range of India – II

A study was conducted to evaluate the effects of supplementing with different tree leaves on nutrient digestion, rumen fermentation and blood parameters of sheep. Thirty adult Malpura rams (39.0 ± 0.56 kg) were divided into five groups of six each. They were grazed as a single flock on a semi-arid rangeland and after the end of routine grazing period (08:00–17:00 h), first group (G1), which was not provided with any supplementation, served as control group. Second group (G2) was supplemented with 200 g of a conventional concentrate mixture per head per day, whereas third, fourth and fifth groups (G3, G4 and G5) were supplemented with approximately 200 g dry matter (DM) per day freshly cut foliage from Ailanthes excelsa, Azardirachta indica and Bauhinia racemosa, respectively. Protein content (g kg⁻¹ DM) in A. excelsa, A. indica and B. racemosa foliage was 197, 128 and 132, respectively. A. indica and B. racemosa foliages also contained 123.2 and 211.2 g kg⁻¹ DM condensed tannin (CT) with protein precipitating capacity (PPC) of 16.5 and 46.5 g kg⁻¹ DM. None of the tree leaves contained hydrolysable tannin (HT). Dry matter intake (DMI, g day⁻¹) was 591, 766, 865, 974 and 939 in G1, G2, G3, G4 and G5, respectively. Digestible crude protein (DCP) and metabolisable energy (ME) intakes in supplemented groups G2–G5 were higher (P < 0.05) compared to control (G1). Supplementation improved digestibility of all nutrients in all groups. Rumen fermentation study indicated lower (P < 0.05) ammonia and total N in the rumen liquor collected from G5 sheep compared to the other supplemented groups. Although haemoglobin (Hb, g dl⁻¹) levels showed small changes among groups, blood urea nitrogen (BUN, mg dl⁻¹) was lowest in G5 compared to the other groups. Initial BW were similar among the groups. After 60 days of experimental feeding, all animals maintained their BW, except sheep in the control group (G1), which lost BW. Results indicate that for adult sheep grazing on a semi-arid range, supplementation with a concentrate mixture could be replaced by tree leaves like A. excelsa, A. indica and B. racemosa, during the lean season to maintain their BW. In addition, supplementing with tree leaves containing condensed tannin has advantages in terms of N utilization.     

Effects of Acacia nilotica, A. polyacantha and Leucaena leucocephala leaf meal supplementation on performance of Small East African goats fed native pasture hay basal forages

Optimal utilisation of tannin-rich browse tree fodders including Acacia spp. foliages as crude protein (CP) supplements to ruminants in the tropics is limited by less available information on their feed nutritive potential. Two studies were conducted to: (1) determine rate and extent of ruminal dry matter (DM) degradability (DMD) and (2) investigate effect of sun-dried Acacia nilotica (NLM), A. polyacantha (PLM) and Leucaena leucocephala leaf meal (LLM) supplementation on growth performance of 20 growing (7–9 months old) Small East African male goats (14.6 ± 0.68 kg) fed on native pasture hay (NPH) basal diet for 84 days in a completely randomised design experiment in north-western Tanzania. The goats were randomised into four treatment groups consisting of five animals each. Three supplement diets: 115.3 g NLM (T₂), 125.9 g PLM (T₃) and 124.1 g LLM (T₄), which was used as a positive control, were supplemented at 20% of the expected DM intake (DMI; i.e., 3% body weight) to the three animal groups fed on NPH (basal diet) compared to the animals in a control group that were fed on NPH without browse supplementation (T₁).

NPH had significantly the lowest (P < 0.05) CP of 45.5 g kg⁻¹ DM compared to NLM, PLM and LLM (159, 195 and 187 g kg⁻¹ DM, respectively). NPH had higher (P < 0.05) fibre fractions; lower ruminal DM degradability characteristics and ME than NLM, PLM and LLM. Supplementation of the animals with browse resulted to (P < 0.05) higher average daily weight gains (ADG) of 157.1 g day⁻¹ in T₄ than the animals fed on T₂ (114.3 g day⁻¹) and T₃ (42.9 g day⁻¹), and even to those fed on T₁ (control), which lost weight (−71.4 g day⁻¹). Improved weight gains were mainly due to corrected feed nitrogen (N) or CP due to supplementation of the animals with browse fodder. Too low CP of the NPH would not meet the normal requirements of CP (80 g CP kg⁻¹ DM) for optimal rumen microbial function in ruminants. Higher ADG due to LLM (T₄) and NLM (T₂) supplementation suggest optimised weight gains due to browse supplementation (20% of expected DMI); while lower weight gains from supplementation with PLM (T₃) indicate the possible utilisation of A. polyacantha leaves to overcome weight losses especially during dry seasons.     

The influence of sulphur,molybdenum and cadmium exposure on the growth of goat,cattle and pig

A three factorial designed feeding experiment with common carp (Cyprinus carpio L.) was carried out in an intensive experimental rearing system. Fish (initial body weight 200 g) were fed on two different levels of dietary energy (16 and 18 MJ DE/kg DM), two different levels of protein (320 and 420 g CP/kg DM) and also two different feeding intensities (100% and 75% of the maximum intake). The experiment was terminated when fish reached a mean body weight of 1300 g.

Growth, feed utilization and nutrient composition of the whole body and fillet were observed. The highest growth was obtained when the fish were fed on the diet containing high dietary energy and high dietary protein with satiation feeding. High dietary energy, high dietary protein and restriction of feed intake improved feed conversion ratios. High dietary energy, low dietary protein and restrictive feeding increased energy utilization. Low dietary protein and restrictive feeding resulted in better protein utilization.

Fish fed with high dietary energy contained more fat and less protein in their carcasses. A lower fat content but higher protein and higher ash content in fish carcasses was shown when fish were fed with a diet high in protein and fed restrictively.     

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.     

Evaluating standardized ileal digestibility of amino acids in growing pigs

The ileal digestibility coefficient (CSID) of amino acids (AA) and crude protein (CP) in 40 feedstuffs for growing pigs were determined with the protein-free (PF) and enzyme-hydrolyzed casein (EHC) methods. The 40 feedstuffs that were used earlier were 10 samples of cereals and cereal by-products, 12 samples of legumes, 6 samples of animal protein feedstuff and 12 samples of oil seed meals. Six growing pigs (initial body weight of 35 ± 1.5 kg), fitted with T-cannula at the terminal ileum, were randomly allocated to either a PF or a EHC diet according to a crossover design during two ileal digesta collection periods. In each period, pigs were adjusted to the experimental diets for 5 days. On days 6 and 8, ileal digesta were collected continuously for 24 h to determine ileal endogenous AA and CP losses. Pigs fed the EHC diet had a higher ileal flow of endogenous CP and of most of AA (P<0.05) than pigs fed the PF diet. Among the ileal endogenous AA flows (g/kg dry matter intake for pigs), methionine excretion was the lowest in pigs (0.09 and 0.25 g/kg dry matter intake) fed the PF and EHC diet, respectively, whereas glutamate (1.83 g/kg dry matter intake) and proline (1.22 g/kg dry material intake) excretion were the highest in pigs fed the EHC and the PF diet, respectively. Endogenous losses of CP and AA determined in the current study and previously published data on apparent ileal digestibility [Yin, Y.L., Huang, R.L., Zhong, H.Y., Chen, C.M., Li, T.J., Pan, Y.F., 1993. Nutritive value of feedstuffs and diets for pigs: 1. Chemical composition, apparent ileal and fecal digestibilities. Anim. Feed Sci. Technol. 44, 1–27] were used to calculate CSID coefficients. For most cereals and cereal by-products, the CSID coefficients of CP determined by the EHC method were higher than those determined by the PF method. Arginine, lysine, methionine, threonine, valine, alanine, aspartate, glutamate, glycine, proline and serine in some cereals and cereal by-products; methionine, valine, alanine and proline in some legumes; and methionine, alaline and proline in some oilseed meals had higher CSID determined by the EHC method than the PF method indicating that there are methodological differences when evaluating the CSID of feed ingredients.     

A comparison between meals prepared from the seeds of different varieties of lupin as protein supplements to barley-based diets for growing pigs

Four experiments were conducted in order to examine the growth and voluntary feed consumption of young growing pigs fed on barley-based diets containing as the sole protein supplement lupin-seed meal (LSM) from either Lupinus angustifolius cv. Uniwhite (UW), Uniharvest (UH) or L. albus cv. Neuland (NL).Under the restricted feeding regimen of the first experiment pigs receiving diets containing either 31% or 43% of either UW or UH grew at similar rates and with similar efficiency of feed utilisation from 27.5 to 85 kg live weight. By contrast, all pigs fed on diets containing these same proportions of NL refused such large amounts of feed immediately after the diets were offered that their growth halted.In the second and third experiments the voluntary feed consumption of pigs weighing 18 to 34 kg and receiving diets containing 37 to 43% of any of three distinct lines of NL was significantly less than those of pigs receiving UW diets, to the extent in some cases that body-weight loss occurred.In the fourth experiment the growth and voluntary feed intakes of 20 to 30 kg pigs fed on a control diet containing a mixture of fishmeal and dried blood as the protein supplement were greater than those of pigs fed a UW diet, which in turn were greater than those of pigs receiving NL as the source of supplementary protein. Reduction of the alkaloid content of NL by ethanol extraction resulted in a recovery of growth and feed intake to levels similar to those supported by the UW diet.     

Dimethylthiourea protects against mitochondrial oxidative damage induced by cisplatin in liver of rats

Cisplatin is one of the most effective chemotherapeutic agents. However, at higher doses liver injury may occur. The purpose of this study was to explore whether the hydroxyl radical scavenger dimethylthiourea (DMTU) protects against cisplatin-induced oxidative damage in vivo and to define the mitochondrial pathways involved in cytoprotection. Adult male Wistar rats (200–220 g) were divided into four groups of eight animals each. The control group was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml/100 g body weight). The DMTU group was given only DMTU (500 mg/kg body weight, i.p), followed by 125 mg/kg body weight, i.p. (twice a day) until sacrifice. The cisplatin group was given a single injection of cisplatin (10 mg/kg body weight, i.p.). The DMTU + cisplatin group was given DMTU (500 mg/kg body weight, i.p.), just before the cisplatin injection (10 mg/kg body weight, i.p.), followed by injections of DMTU (125 mg/kg body weight, i.p.) twice a day until sacrifice (72 h after the treatment). DMTU did not present any direct effect on mitochondria and substantially inhibited cisplatin-induced mitochondrial damage in liver, therefore preventing elevation of AST and ALT serum levels. DMTU protected against (a) decreased hepatic ATP levels; (b) lipid peroxidation; (c) cardiolipin oxidation; (d) sulfhydryl protein oxidation; (e) mitochondrial membrane rigidification; (f) GSH oxidation; (g) NADPH oxidation; (h) apoptosis. Results suggest that antioxidants, particularly hydroxyl radical scavengers, protect liver mitochondria against cisplatin-induced oxidative damage. Several mitochondrial changes were delineated and proposed as interesting targets for cytoprotective strategy.     

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%.     

饲料中添加甘草酸对刺参生长、免疫及抗病力的影响

以初始体重为(6.80±0.00)g左右的刺参(Apostichopus japonicus Selenka)为研究对象,在室内循环水系统中进行8周饲喂实验,研究饲料中添加不同梯度的甘草酸对刺参生长、免疫及其抗病力的影响。以基础饲料为对照组,在基础饲料中分别添加50、100和200mg/kg的甘草酸,共配制4种实验饲料。结果表明:饲料中添加甘草酸对刺参的成活率没有影响,各处理组均为100%。饲料中添加200mg/kg甘草酸可显著提高刺参的特定生长率(SGR)(P0.05)。养殖实验结束后,通过注射刺参腐皮综合症致病菌灿烂弧菌(Vibriosplendidus)进行刺参攻毒实验,攻毒后14d内对照组与50mg/kg添加组的累计发病率(分别为38.3%和36.7%)显著高于100和200mg/kg添加组(分别为30.0%和26.7%)(P<0.05)。实验可得到以下结论:(1)饲料中添加200mg/kg甘草酸可以提高刺参养殖的产量,同时可以提高刺参的非特异性免疫力和抗病力;(2)在研究中,全周期养殖期间投喂甘草酸不会产生免疫疲劳或其他副作用。       

Sulphur amino acid requirement of juvenile Asian sea bass Lates calcarifer

The dietary requirement of juvenile Asian sea bass Lates calcarifer Bloch for total sulphur amino acids was studied. Fish (average initial weight of 2.59 ± 0.08 g) were reared in twelve 500 L fibreglass tanks provided with flow-through seawater at 26°C and salinity of 31 p.p.t. for 12 weeks. They were fed semi-purified test diets containing 6.2, 7.2, 8.1, 9.0, 10.8, or 12.6 g methionine kg⁻¹ dry diet and a basal level of 3.1 g cystine kg⁻¹ dry diet. The mean crude protein of the diets (containing defatted Peruvian fishmeal, squid meal, soybean meal, and free amino acid mixture to simulate the pattern of hydrolysed sea bass protein) was 46.02%. The crude fat content of the diets was 10.51% from a 1 : 1 mixture of cod liver oil and soybean oil. Survival was 100% in all treatments. On the basis of the growth response, the total sulphur amino acid requirement of juvenile Asian sea bass was estimated to be 13.4 g kg⁻¹ dry diet (2.9% of protein). Fish fed low levels of l -methionine had significantly lower weight gains and feed efficiency ratios as well as slightly higher hepatosomatic indices. No nutritional deficiency signs were observed other than growth depression in fish fed on diets that were low in methionine. This information is valuable in further refinement of formulations of practical diets for the Asian sea bass.     

Effect of the proportions of neutral detergent fibre and starch, and their degradation rates, on in vitro ruminal fermentation

Effects of proportions of neutral detergent fibre (aNDFom) and starch, as well as their degradation rates, on rumen fermentation were tested using an in vitro rumen simulation system (SIMCO). The in vitro system was designed to simulate selective particle retention and had an average fluid volume of 1150 ml with a liquid dilution rate of approximately 0.07 h⁻¹. Two types of hay (aNDFom sources) and two types of starch were each included at two different levels in the diet and were examined in an experiment following a 2×2×2 factorial arrangement of treatments (eight diet combinations). The hay was either late-cut timothy (Phleum pretense L.) or early cut meadow grass (Poa pratensis L.), with ruminal in situ aNDFom digestion rates of 0.03–0.04 and 0.07–0.08 h⁻¹, respectively. The two starch types were raw (R) and cooked (C) potato starch with previously determined in vitro ruminal digestion rates of 0.04 and 0.20 h⁻¹, respectively. The starch levels were 300 and 600 g/kg diet dry matter (DM) with the remaining being hay (282–682 g/kg DM) and peptone (14–111 g/kg DM). The aNDFom level varied among the diets with different starch levels and hay types. The peptone acted as a source of peptides and, together with ammonia salts from buffer, was used to balance the N contents of the diets. The feeding level for each of the eight vessels was 28 g DM/d. Two 10-day simulations were made with the system. The average pH was higher (P<0.05) for all treatments with raw potato starch (6.19) versus cooked starch (6.07). Protozoa scores, on a qualitative scale, declined faster at the higher starch level. The aNDFom digestibility was, as expected, higher (P<0.001) for meadow hay (0.57) than timothy (0.32), and was also higher (P<0.001) at the lower starch level (0.54) versus the higher (0.35). Microbial protein production efficiency (mg microbial N/g organic matter truly digested) was higher for the faster degrading aNDFom (P<0.01) and starch (P<0.05) sources, but was not affected by starch level. Cooked starch resulted in a lower acetate proportion (449 mmol/mol versus 591 mmol/mol VFA; P<0.001) but higher proportions of propionate (297 mmol/mol versus 236 mmol/mol VFA; P<0.001), and butyrate (169 mmol/mol versus 127 mmol/mol VFA; P<0.01). Butyrate increased with starch level (127 mmol/mol versus 169 mmol/mol VFA; P<0.01), and was also higher for meadow hay versus timothy (168 mmol/mol versus 128 mmol/mol VFA; P<0.01). Interactions between the treatments demonstrate that the response in VFA pattern to starch level is dependent on starch and aNDFom sources. Substrates such as starch and aNDFom are fermented differently depending on their rates of ruminal degradation.