Influence of dietary rapeseed meal levels on growth performance,organ health and standardized ileal amino acid digestibility in meat ducks from 15 to 35 days of age

This study was conducted to investigate the effects of dietary rapeseed meal (RSM) inclusion levels on growth performance, organ health and standardized ileal amino acid digestibility (SIAAD) in meat ducks from 15 to 35 days of age. Six hundred and eighty 15‐days‐old ducks were randomly allotted to five treatments based on body weight. Five isonitrogenous and isoenergetic diets were formulated on a digestible amino acid basis by replacing 0% (the control), 25%, 50%, 75% and 100% (based on fresh) of protein from soya bean meal (SBM) with protein from RSM. The corresponding levels of RSM in experimental diets were 0%, 6.66%, 13.32%, 19.98% and 26.64% respectively. With increasing dietary RSM levels, body weight (BW) and average daily gain (ADG) linearly decreased (p < 0.001), whereas feed‐to‐gain ratio (F: G) linearly increased (p = 0.0078). Ducks fed the diets with 13.32% or more RSM had significantly lower (p < 0.05) BW, ADG and ADFI, or higher F: G than ducks fed the control diet. The maximum limit of dietary RSM supplementation was estimated to range from 4.27% to maximize ADG for 15 to 35 days to 11.69% to maintain feed intake for 15 to 35 days on the basis of a broken‐line model. At day35, the 4th primary wing feather length and SIAAD (except for Met, Thr and Val) linearly decreased (p < 0.001), and the thyroid glands weight (% of BW) linearly increased (p < 0.05) with increasing dietary RSM levels. Ducks fed the RSM inclusion diets had significantly lower (p < 0.0001) serum aspartate aminotransferase (AST) and alanine transaminase (ALT) activities than ducks fed the control diet. These results suggested that the maximum limit of dietary RSM containing 7.57 μmol/g glucosinolates was estimated to be 4.27% to avoid growth reduction.     

Effect of dietary concentrate content on feed intake,feed efficiency,and meat quality of Holstein steers fattened in a hot environment

The objective of this study was to investigate the effect of feeding high and low concentrate diets on feed intake and feed efficiency, the morphological characteristics of the rumen papillae, and meat quality of Holstein steers fattened under hot climate conditions in Oman. Ten male Holstein calves, of 5 months of age, were selected for the experiment. The animals were fed concentrate and Rhodes grass hay and were divided into two groups of high concentrate (HC, n = 5) and low concentrate diets (LC, n = 5), in which their feed intake, weight gain, and feed efficiency were evaluated across three growing periods. Feed intake and efficiency and average daily gain (ADG) of the HC group were significantly greater than for the LC group and were affected by the diet (p < .01) and the period (p < .001). Across the fattening periods, ADG declined in both groups, with ADG improved by 35% for steers on the HC diet compared to steers on the LC diet. Carcass meat quality was not affected significantly by the dietary concentrate level. In conclusion, our results can be used to make improvements in feed efficiency of Holstein steers under hot climate conditions.     

Effects of multistrain probiotics on growth performance,nutrient digestibility,blood profiles,faecal microbial shedding,faecal score and noxious gas emission in weaning pigs

This experiment was conducted to investigate the efficacy of multistrain probiotics in weaning pigs. A total of 125 28‐day‐old weaning pigs [(Landrace × Yorkshire) × Duroc] with an initial average body weight (BW) of 7.26 ± 0.76 kg were randomly allotted into 5 treatments, 5 replicate pens/treatment with 5 pigs/pen for 42‐day experiment. Dietary treatments were as follows: CON, basal diet; PC1, CON + 0.01% multistrain probiotics; PC2, CON + 0.03% multistrain probiotics; PC3, CON + 0.06% multistrain probiotics; PC4, CON + 0.1% multistrain probiotics. On day 14, pigs fed the PC4 diet had higher BW gain than pigs fed the CON diet. On day 42, pigs fed multistrain probiotics supplementation diets had higher BW gain than pigs fed the CON diet. From days 1 to 14, pigs fed the PC2, PC3 and PC4 diets had higher (p < 0.05) ADG than pigs fed the CON diet. From day 15 to 42, pigs fed the multistrain probiotics supplementation diets had higher (p < 0.05) average daily gain (ADG) and gain: feed ratio (G:F) than pigs fed the CON diet. In the overall period, pigs fed the multistrain probiotics supplementation diets had higher (p < 0.05) ADG and pigs fed the PC2 and PC4 diets had higher (p < 0.05) G:F than pigs fed the CON diet. On day 42, pigs fed the PC4 diet had higher (p < 0.05) apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N) and gross energy (GE), faecal Lactobacillus counts and lower (p < 0.05) E. coli counts and NH₃ emission than pigs fed the CON diet. Pigs fed the multistrain probiotics supplementation diets had lower (p < 0.05) H₂S and total mercaptans emissions than pigs fed the CON diet. Conclusions, dietary supplementation with 0.1% probiotics improved growth performance, nutrition digestibility and intestinal microflora balance and decreased faecal noxious gas emissions in weaning pigs.     

Effect of urea supplementation on performance and safety in diets of Dorper crossbred sheep

This study was conducted to evaluate the efficacy and safety of dietary urea in sheep rations having a 50:50 concentrate:roughage ratio. Sixty‐four Dorper × thin‐tailed Han crossbred ram lambs with an average body weight of 30.8 (±0.02) kg were randomly divided into four groups of 16 sheep each, and each group was fed one of the following diets: a basal diet (CON), or CON supplemented with 0.5% (0.5UTM), 1.5% (1.5UTM) or 2.5% (2.5UTM) urea. Growth performance, carcass characteristics, non‐carcass offals, meat quality and peptic tissue lesions were assayed. The average daily weight gains for CON, 0.5UTM, 1.5UTM and 2.5UTM were 216, 218, 200 and 170 g, respectively, with the CON and 0.5UTM groups higher than 2.5UTM group (p < 0.05). Sheep from the 2.5UTM treatment had a significantly lower dry matter intake (1.29 kg/day) than those from the CON and 0.5UTM treatments (1.42 and 1.43 kg/day, p < 0.05), and the feed conversion ratio in the 2.5UTM group was the highest (p < 0.05). Carcass characteristics, including shrunk body weight, empty body weight, hot carcass weight, dress percentage, and the absolute or relative weight (% body weight) of heart, liver, spleen, lung and kidney, were not altered by the treatments (p > 0.05). The muscular pH of 2.5UTM was higher than that of CON (5.68 vs. 5.52, p < 0.05), and shear force in 0.5UTM was lower compared with CON and 2.5UTM (p < 0.05). The anatomical structure lesions in kidneys became more serious with the increasing dietary urea concentrations, with the 2.5UTM animals showing the most severe lesions compared with CON animals. Therefore, supplementary urea as a non‐protein nitrogen source for sheep should not exceed 1.5% of ration having a 50:50 concentrate:roughage ratio to ensure efficacy and safety.     

Influence of Bacillus subtilis GCB‐13‐001 on growth performance,nutrient digestibility,blood characteristics,faecal microbiota and faecal score in weanling pigs

The present study investigated the influence of Bacillus subtilis GCB‐13‐001 on growth performance, nutrient digestibility, blood characteristics, faecal microbiota and faecal score in weanling pigs. A total of 120 weaning pigs [(Landrace × Yorkshire) × Duroc; 7.73 ± 0.75 kg (28 days of age)] were randomly allotted into three treatments according to their initial body weight (BW) and gender in a 6‐week experiment. There were 8 replication pens in each treatment, with five pigs/pen. Dietary treatment groups were as follows: (a) basal diet (CON), (b) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁸ CFU/kg (T1) and (c) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁹ CFU/kg (T2). Days 1 to 7, the BW and ADG with T2 treatment were higher (p < .05) than CON treatment, as well as F:G showed trends in linear reduction (p < .1). Days 8 to 21, the BW and ADG were improved (p < .05) in pigs offered T1 and T2 diets compared with CON diet. Days 22 to 42, BW and ADG were higher (p < .05) in pigs fed T2 diet than CON and T1 diets, and the pigs fed T1 diet had higher BW than CON treatment. Overall, the ADG with the T2 treatment was higher (p < .05) than that with the T1 and CON treatments, and pigs offered T1 treatment had higher (p < .05) ADG than CON treatment. Moreover, F:G ratio were significantly decreased (p < .05) by T2 treatment compared with CON treatment. The faecal Lactobacillus counts were improved, and E. coli counts were reduced (p < .05) in pigs fed T2 diet compared with CON at the end of the experiment. In conclusion, supplementation of 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁹ CFU/kg has shown a beneficial effect in improving BW, increase ADG, decrease F:G ratio.     

Meat goat diet supplementation with crude glycerine: Ruminal fermentation metabolism,blood chemistry profile,animal performance and carcass traits

The objective of this experiment was to determine the effects of feeding varying levels of crude glycerine (CG) on dry matter intake (DMI), animal performance, carcass traits and rumen volatile fatty acids (VFA) concentration in meat goats. Twenty-four intact male Boer goats (23.9 ± 1.0 kg initial BW and 4–5 months of age) were randomly assigned to one of four experimental diets (n = 6) containing 30% bermudagrass hay plus 70% concentrate mix with 0, 5, 10 or 15% CG in the diet on an as-fed basis, substituted for the corn portion of the concentrate. Feed offered and refusals were monitored daily for 84 days. Goats were weighed at 28-days interval. Blood and rumen samples were collected on day 84. At the end of the 84-days feeding period, goats were harvested, and carcass characteristics measured. Feed intake, average daily gain (ADG), gain-to-feed ratio (G:F), carcass traits and VFA concentrations were analysed as a completely randomized design. The CG did not influence animal body weight (BW) changes, ADG and G:F ratio but tended to (p = 0.06) decrease DMI. Molar per cent propionic acid increased linearly (p < 0.05) with increasing CG. The acetate: propionate (A:P) ratio decreased (p < 0.05) with increasing amounts of CG in the diet. The CG addition tended to increase (p = 0.09) the longissimus muscle (LM area) in meat goats. In conclusion, CG can replace corn in diet for growing meat goats when fed up to 15% of diet, improving ruminal propionate concentration, but decreasing A:P ratio without affecting animal performance and carcass traits.     

Responses of male broiler chickens from two genetic groups to different stocking densities in a semi-arid subtropical environment

The effects of stocking densities of 30, 35, 40 and 45 kg body weight (BW)/m² on the growth performance of Ross 308 and Hubbard broiler chickens were studied in a 49-day production period. Ross 308 was superior to Hubbard in weight gain and market weight and consumed more feed (p < 0.05) but the strains did not differ significantly in feed efficiency, mortality rate and abdominal fatness. Overall, birds raised at stocking densities of 30, 35 and 40 kg BW/m² performed equally well in weight gain, feed consumption and 49-day live weight and outperformed those raised at 45 kg BW/m² (p < 0.05). It is suggested that for profitable broiler production under tropical conditions Ross 308 and stocking density of 40 kg BW/m² be considered.     

Dietary lysine requirement for 7–16 kg pigs fed wheat–corn–soybean meal‐based diets

Two experiments were conducted to determine the lysine requirement of weaned pigs [Duroc × (Yorkshire × Landrace)] with an average initial BW of 7 kg and fed wheat–corn–soybean meal‐based diets. The experiments were conducted for 21 days during which piglets had free access to diets and water. Average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F) were determined on day 7, 14 and 21. Blood samples were collected on day 0 and 14 to determine plasma urea nitrogen (PUN) concentration. In experiment 1, 96 weaned pigs were housed four per pen and allocated to four dietary treatments with six replicates per treatment. The diets contained 0.99%, 1.23%, 1.51% and 1.81% standardized ileal digestible (SID) lysine, respectively, corrected analysed values. The rest of the AA were provided to meet the ideal AA ratio for protein accretion. Increasing dietary lysine content linearly increased (p < 0.05) ADG and G:F. In experiment 2, 90 piglets were housed three per pen and allocated to five dietary treatments with six replicates per treatment. The five diets contained 1.03%, 1.25%, 1.31%, 1.36% and 1.51% SID lysine, respectively, corrected analysed values. Increasing dietary lysine content linearly increased (p < 0.05) G:F, linearly decreased (p < 0.05) day‐14 PUN and quadratically (p < 0.05) increased ADG and ADFI. The ADG data from experiment 2 were subjected to linear and quadratic broken‐lines regression analyses, and the SID lysine requirement was determined to be 1.29% and 1.34% respectively. On average, optimal dietary SID lysine content for optimal growth of 7–16 kg weaned piglets fed wheat–corn–SBM‐based diets was estimated to be 1.32%; at this level, the ADG and ADFI were 444 and 560 g, respectively, thus representing an SID lysine requirement, expressed on daily intake basis as, 7.4 g/day or 16.76 mg/g gain.     

Effects of animal type (wild vs. domestic) and diet alfalfa level on intake and digestibility of European adult rabbits (Oryctolagus cuniculus)

The aim of this study was to evaluate the effect of the level of alfalfa in the diet on feed intake and digestibility of two types of rabbits, wild (Oryctolagus cuniculus algirus) vs. domestic (O. cuniculus cuniculus). Ten wild (W; mean LW = 927 g) and 10 domestic (D; mean LW = 4,645 g) adult rabbit does were fed ad libitum two pelleted diets: a control diet (C) with 15% of dehydrated alfalfa hay (as feed basis) and a test diet (A) with 36% of dehydrated alfalfa hay (as feed basis), according to a change‐over design. Wild does dry matter (DM) intake per kg live weight (BW) was 55% higher (p < .001) than the intake of the D ones (58 g vs. 37 g DM per kg BW respectively). However, no difference (p > .05) was found when intake was expressed per kg^0.75 BW (ca. 56 g DM) and tended to be higher (p = .07) in D does when expressed per kg^0.67 BW (62 g vs. 55 g DM). Domestic does showed a higher (p < .05) DM, organic matter, crude energy and neutral detergent fibre digestibility (3; 2; 3; 3 percentage points respectively) than W does. The amount of nutrients and energy digested by D does was lower per kg BW (p < .001), similar per kg^0.75 BW (p > .05) and tended to be higher per kg^0.67 BW (p < .1) than in W does. The diet content of alfalfa did not affect (p > .05) the feed intake nor the diet digestibility. This study suggests that W rabbits exhibit a higher intake per kg BW and a lower digestibility than their D counterparts, which results in similar digestible nutrient and energy intake per kg BW powered to 0.75. The nutritive value of dehydrated alfalfa for rabbits, evaluated through intake and digestibility, seems to be equivalent to their base diets (forage plus concentrate).     

Dietary methionine requirement of Jing Brown layer hens from 9 to 17 weeks of age

This study was conducted to evaluate the effect of dietary methionine (Met) supplementation in growth performance and reproductive performance of Jing Brown layer hens. A total of 375 9‐week‐old Jing Brown layer hens were allocated equally to five treatments consisting of 5 replicates with 15 hens. Hens were fed with a diet of corn and soya bean meal supplemented with 0.23%, 0.27%, 0.31%, 0.35% and 0.39% Met respectively. Different Met levels did not significantly affect average daily feed intake (ADFI), average daily gain (ADG) and feed/gain ratio (F/G) (p > 0.05), whereas flock uniformity (FU) and jejunum index were significantly different (p < 0.05), and the largest FU was observed in 0.31% Met. Dietary supplementation of Met significantly affected reproductive system development (p < 0.05), and 0.27–0.31% Met obtained optimal reproductive system development. Different Met levels significantly affected serum uric acid and alkaline phosphatase. Moreover, the relatively higher reproductive hormones in serum were observed in 0.27% Met. Analysis of quadratic curve estimation of flock uniformity, the total number of follicles, the primary follicles and the secondary follicles showed that the optimal Met levels were 0.293%, 0.286%, 0.286% and 0.288%, which could be averaged to 0.288%. These results suggested that the optimal Met requirement for Jing Brown layer hens from 9 to 17 weeks old is 0.29%.     

Performance and hemtochemical parameters of buck‐kids fed concentrate partially replaced with tropical Piliostigma thonningii foliage

Fifteen 5‐month‐old Red Sokoto buck‐kids, (6.6 ± 0.71 kg body weight (BW)) randomly distributed into three groups of five animals per group, were used to study the effects of supplementary concentrate partially replaced with Piliostigma thonningii (PT) foliage on the growth performance, economic benefit and blood profile in a completely randomized design using analysis of variance. The goats in group 1 received 100% supplementary concentrates (PT0), groups 2 and 3 received 25% (PT25) and 50% (PT50), respectively, of concentrate replaced with an equal amount (dry matter basis) of Piliostigma foliage. The goats were fed a basal diet of threshed sorghum top (TST). Intake of concentrate, hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, total feeding cost and cost/kg BW were greater (P < 0.05) for PT0 than for PT25 and PT50. Consumption of P. thonningii foliage was greater (P < 0.05) for PT50 relative to PT25. Tannin consumption of the treatment diets were greater (P < 0.05) than that of the control concentrate diet. Serum urea N reduced (P < 0.05) with increasing level of concentrate replacement, while serum glucose was higher (P < 0.05) in PT0 than in PT50. However, means of all blood measurements were within normal ranges for goats. Net benefit showed this rank order: PT0 < PT50 < PT25 (all P < 0.05). Both differential and relative benefits were higher (P < 0.05) for PT25 than for PT50. P. thonningii foliage can replace 50% of supplemental concentrate without impairing feed intake, growth performance and health of buck‐kids.     

Effect of concentrate extrusion and castration on diet digestion and performance of intensively reared male calves

Fifty-six male Friesian calves, half of them castrated, were used to study the effects of concentrate extrusion and animal castration on diet digestibility and performance in two different growth phases (from 91 to 250 and from 250 to 400 kg live weight). Diets consisted of a compound meal, extruded or nonextruded, and barley straw, both of them fed ad libitum. Half of the animals were slaughtered at 250 kg and the remaining at 400 kg live weight. Extrusion increased the gelatinization grade, resulting in a higher (p<0.01) fermentation rate, and reduced nitrogen solubility and degradation after 12 h of rumen incubation (p<0.05). Calves receiving the extruded meal showed a lower rumen ammonia concentration just before the first meal (p<0.001), the differences disappearing afterwards. Neither the pH nor the total VFA concentrations were affected, although butyrate, isobutyrate and isovalerate proportions before the first meal decreased with the extruded diet. Concentrate extrusion did not affect the apparent OM digestibility of total diet but caused a reduction of NDF (p<0.01) and CF (p<0.05) digestibility. In the first growth phase, concentrate and total DM intake decreased with extrusion (p<0.001), without affecting the average daily gain (ADG). Consequently, the concentrate and total feed conversion ratios were significantly lower (p<0.001 and p<0.01, respectively) with the extruded meal. Bulls showed a higher ADG than steers (p<0.001), resulting in lower feed conversion ratios (p<0.01) given that intake was not affected by castration. In the second growth phase, extrusion did not affect any of the performance parameters, however bulls showed a higher DM intake and ADG (p<0.05), but no differences in the feed conversion ratio were found between entire and castrated animals.     

Evaluation of total mixed ration silage with brewers grains for dairy buffalo in Tarai,Nepal

To investigate the effects of total mixed ration (TMR) silage, which contained brewers grain and rice straw as a substitute for conventional concentrate on feed intake and milk production in middle‐to‐late lactation buffaloes, four multiparous Murrah buffaloes were assigned to a 3 × 3 Latin square design experiment. The TMR silage, which had higher neutral and acid detergent fiber contents and digestibility than concentrate (P < 0.05) and similar crude protein (CP) and total digestible nutrient (TDN) contents with concentrate were used for the lactation experiment. The treatments were control (CTL) fed concentrate at 0.6% of body weight (BW), and T1 and T2 fed the TMR silage at 0.6 and 1.2% of BW on a dry matter (DM) basis, respectively, with rice straw ad libitum. Daily intakes of DM, CP and TDN, and BW change were higher in T2 than in CTL and T1 (P < 0.05). Although milk composition did not differ among the treatments, milk yield (MY) was higher in T2 (P < 0.05). There were no significant differences in MY/DM intake and MY/TDN intake among the treatments. The increase of BW and MY in middle‐to‐late lactation buffaloes might have been due to high TDN intake from supplementary TMR silage.     

Effects of dietary Bacillus coagulans and yeast hydrolysate supplementation on growth performance,immune response and intestinal barrier function in weaned piglets

The present study investigated the effects of Bacillus coagulans and yeast hydrolysate supplementation on growth performance, immune response and intestinal barrier function of weaned piglets. Twenty-four weaned piglets with an average body weight (BW) of 6.89 ± 0.15 kg were divided into four diets for 28 days. The treatments were basal diet (control), basal diet supplemented with antibiotic (20 mg/kg colistin sulphate and 40 mg/kg bacitracin zinc, AT), probiotics (400 mg/kg Bacillus coagulans ≥5 × 109 CFU/g, BC) or yeast hydrolysate (5000 mg/kg yeast hydrolysate, YH). Average daily gain (ADG) and average daily feed intake (ADFI) were improved by AT and YH diets (p < 0.05), while BC diet only increased ADG (p < 0.05). The complement 3 (C3), lysozyme (LZM) and tumour necrosis factor-α (TNF-α) concentrations in serum were increased in BC diet (p < 0.05). Feeding AT and YH caused the increase of jejunal villus height (p < 0.05), and a higher ratio of villus height/crypt depth was observed in AT, BC and YH groups (p < 0.05). The mRNA expression of zonula occludens-1 (ZO-1) in jejunal mucosa was up-regulated by AT, BC and YH diets (p < 0.05). Dietary AT, BC or YH inclusion decreased the interleukin-1β (IL-1β) concentration and TNF-α mRNA expression (p < 0.05), and YH supplementation even down-regulated toll-like receptor 4 (TLR4) and CD14 expressions (p < 0.05). In summary, the dietary administration of BC or YH both improves growth performance through promoting the intestinal barrier function, indicating both of them can serve as potential alternatives to antibiotics growth promoters for the piglet production.     

Effects of different n‐6 to n‐3 polyunsaturated fatty acids ratio on reproductive performance,fecal microbiota and nutrient digestibility of gestation‐lactating sows and suckling piglets

This study was conducted to evaluate the effects of dietary ratios of n‐6:n‐3 polyunsaturated fatty acids (PUFA) on reproductive performance, fecal microbiota and nutrient digestibility of gestation‐lactating sows and suckling piglets. Fifteen primiparous sows (Landrace × Yorkshire) were randomly allotted into three treatments. Fed diets contained different ratios of n‐6:n‐3 PUFA, including 20:1, 15:1 and 10:1. No differences were detected among the treatments for average daily feed intake (ADFI) of sows and the back fat levels during lactation (P > 0.05). Body weight (BW) loss of sows after farrowing to weanling was greater in the 10:1 treatment compared with 15:1 or 20:1 (P < 0.05). In piglets, a great significant difference for BW was observed at 4 weeks (P < 0.01). Furthermore, average daily gain (ADG) of piglets in the 10:1 treatment was higher (P < 0.05). No difference was observed among treatments in nutrient digestibility of sows (P > 0.05). A great significant difference for fecal microbiota was in the 10:1 treatment compared with 20:1 and 15:1 treatments (P < 0.01). In conclusion, altering the ratio of n‐6:n‐3 PUFA in gestation‐lactating sow diet had no difference on nutrient digestibility in gestation‐lactating sows, but it can partially improve reproductive performance.     

Effects of complex probiotic supplementation in growing pig diets with and without palm kernel expellers on growth performance,nutrient digestibility,blood parameters,fecal microbial shedding and noxious gas emission

In Experiment 1, a total of 100 growing pigs (Duroc × [Landrace × Yorkshire]) with an average initial body weight (BW) of 24.88 ± 1.57 kg were randomly allotted to 2 × 2 factorial arrangement with two concentrations of palm kernel expellers (PKE) in diets at 0% or 10%, and two concentrations of supplemental probiotics at 0 or 6.0 × 10⁷ colony‐forming units/kg. There were five replicate pens per treatment with five pigs per pen. In Experiment 2, eight barrows with average initial BW of 25.78 ± 0.19 kg were allotted to a replicated 4 × 4 Latin square design with four diets and four periods per square. Four experimental diets were the same as Experiment 1. In Experiment 1, dietary probiotic supplementation improved (P < 0.05) the average daily gain (ADG), nutrient digestibility and the fecal Lactobacillus counts. Furthermore, interactive effects (P < 0.05) between PKE and probiotics were observed on ADG and growth‐to‐feed ratio. In Experiment 2, an interactive effect (P < 0.05) of PKE and probiotics was observed in apparent ileal digestibility of nitrogen and some amino acids. In conclusion, dietary probiotics did not improve PKE utilization and the use of probiotics in non‐PKE‐containing diet was more favorable than in PKE‐containing diet.     

The effects of supplemental threonine on performance,carcass characteristics,immune response and gut health of broilers in subtropics during pre‐starter and starter period

Three hundred thirty‐day‐old unsexed commercial broiler chicks (Vencobb‐400) with initial average body weight of 44.04 ± 0.42 g were allocated into five experimental groups, in a completely randomized design (CRD) with 21‐day experiment. Groups were formed according to dose of supplemental L‐threonine in various rations i.e., 100% NRC specification, 100% threonine of Vencobb‐400 strain specification, 110% threonine of Vencobb‐400 strain specification, 120% of threonine of Vencobb‐400 strain specification and 130% threonine of Vencobb‐400 strain specification. Average daily feed intake (ADFI), average daily body weight gain (ADG), cumulative feed conversion ratio (CFCR), carcass characteristics, immune response, intestinal morphometry and biochemical profile were studied. The ADFI and ADG increased linearly and quadratically as dietary threonine levels were increased. However, the CFCR did not differ (p ? 0.05) among the groups. Though the carcass weight and drumstick yield did not differ (p ? 0.05) among the groups, the relative breast yield increased linearly (p = 0.007). The relative dressing yield and relative thigh weight increased linearly (p = 0.05 and p = 0.03, respectively). The relative weight of immune organs like bursa and thymus increased linearly. The mean total serum immunoglobulin, ND‐ELISA titre and the mean lymphocyte proliferation response index increased linearly, whereas mean phagocytic activity index of neutrophil increased linearly (p < 0.001) and quadratically (p = 0.001). The mean villus height (VH), crypt depth (CD), villus surface area and mean goblet cell number/villus increased linearly and quadratically, whereas the villus width (VW) and goblet cell density increased quadratically. The serum glucose increased linearly (p = 0.001), whereas serum total protein concentration and serum globulin level increased both linearly and quadratically. The albumin: globulin ratio tended to decrease linearly. There was a significant decrease (p < 0.05) in serum cholesterol and VLDL cholesterol level. However, a linear increment (p = 0.04) in the blood serum HDL cholesterol level with a linear reduction (p = 0.01) in the blood serum LDL cholesterol was noticed.     

Spray‐dried porcine plasma improves feed intake of weaned piglets subjected to heat stress

The objective of this study was to evaluate the effects of spray‐dried porcine plasma (SDPP) on performance, measurement of thyroid hormones triiodothyronine (T3) and thyroxine (T4), body temperature and relative organ weights of weaned piglets exposed to a heat stress or a thermoneutral environment. One hundred and forty‐four piglets with initial BW of 5.82 ± 0.33 kg (28 d old) were used. The experimental design was a 4 x 2 factorial arrangement, four plasma levels (0.0, 2.5, 5.0 and 7.5%) and two environments (34º [heat stress (HS)] and 24°C [thermoneutral (TN)]). SDPP was fed from weaning (28 d of age) to the end of the trial (piglets were weighed at the beginning, 7, 21 and 35 days of trial). Rectal, neck, shoulder and leg temperatures were measured every seven days. At 21 days of trial, one piglet per pen was slaughtered to determine the weight of the carcass and organs. Blood samples were collected at 18 and 35 days of trial to determine levels T3 and T4. The rectal, neck, shoulder and leg temperatures were increased (p < 0.05) 0.4, 1.5, 1.0 and 1.3ºC, respectively, and relative weight of the lungs (p < 0.05) and total T3 (p < 0.05) were decreased 0.001 kg/kg and 0.19 ng/dl, respectively, for pigs in the HS environment. The estimated inclusion of 5.1% of SDPP had the greatest (p < 0.05) weight gain during the first week, and throughout the nursery phase, the 5% of inclusion had a tendency of improvement (p = 0.075), regardless of ambient temperature. For the entire period, pigs reared in the HS environment had the greatest (p < 0.05) estimated feed intake by the quadratic regression with the inclusion of 4.3% of SDPP.     

Effects of limit‐feeding diets with different forage‐to‐concentrate ratios on nutrient intake,rumination, ruminal fermentation,digestibility, blood parameters and growth in Holstein heifers

The objective of this study was using a wide range of dietary concentrate levels to investigate the major effects of limit‐feeding on heifers. Twenty‐four Holstein heifers were blocked into six groups and fed with one of four diets containing different levels of concentrate (20%, 40%, 60% and 80% on a dry matter (DM) basis) but with same intakes of metabolizable energy for 28 days. Increasing levels of dietary concentrate caused decreased (P ≤ 0.02) intakes of dry matter (DMI) and neutral detergent fiber and total rumination time, but increased (P < 0.01) nonfiberous carbohydrates intake, ruminal concentrations of NH₃‐N, propionate and butyrate, and digestibility of DM and crude protein. Dietary concentrate levels had no significant effect on most plasma concentrations and body measurements. The corrected average daily gain (CADG) and feed efficency (ADG/DMI, CFE) were linearly increased (P < 0.01) with increasing dietary concentrate levels when gut fill impact was removed. In conclusion, heifers limit‐fed high concentrate diets increased most ruminal fermentation parameters, CADG and CFE with similar body growth and blood metabolites as heifers fed low concentrate diets, and had the potential to be used as an effective feeding strategy in dairy heifers.     

Influence of various concentrate‐to‐roughage ratios on dietary intake and nutrient digestibilities of weanling horses

The objective of this study was to compare the feed intake and the apparent digestibilities of three different diets varying in concentrate‐to‐roughage ratios in weanling horses (n = 24) at 5 and 8 months of age. Horses were stratified by breed, gender, birth date and body weight and assigned to one of three dietary treatments containing the following concentrate‐to‐roughage ratios on an as‐fed basis: 70:30 (High Con), 50:50 (Equal) and 30:70 (Low Con). All horses were fed their respective diets for a 10‐day adaptation period and a 4‐day collection period at 5 and 8 months. There were no differences in BW or daily feed intake among treatments during both trials. The horses consuming Low Con had a greater amount of faecal output than High Con at both 5 and 8 months (p < 0.01). At 5 months, High Con had the highest crude protein (CP) digestibility (p < 0.05). At 8 months, High Con had a higher CP digestibility than Low Con (p < 0.01) and tended to be higher than Equal (p = 0.07). Acid detergent fibre (ADF) digestibility did not differ among treatments; however, horses fed the Low Con tended to digest a higher percentage of neutral detergent fibre (NDF) than both the Equal and High Con treatments (p = 0.09). Horses in the High Con treatment tended to digest a higher percentage of energy than those in the Low Con treatment (p = 0.06). Weanlings seem to digest protein more thoroughly when fed high‐concentrate diets and may digest fibre more efficiently when fed diets higher in fibre.