Dietary zinc requirement of juvenile stinging catfish Heteropneustes fossilis based on growth performance, haematology, and tissue mineral composition.

This investigation was done to determine how much zinc (Zn) the stinging catfish, Heteropneustes fossilis, needs in its diet. Five isonitrogenous (34.5% protein) and isolipidic (6.0% lipid) diets were prepared to contain graded levels of Zn (0, 10, 20, 30, and 40 mg kg-1), supplied as zinc sulfate (ZnSO4·7H2O), and referred to as Zn0, Zn10, Zn20, Zn30, and Zn40, respectively. A total of 600 fish (initial body weight: 1.41 ± 0.02 g) were stocked in 15 glass aquaria (40 fish/aquarium), each with 180 L water capacity. For ten weeks, each diet was hand fed to three groups of fish twice daily until they appeared satisfied. The highest weight gain and specific growth rate, and lowest feed conversion ratio were recorded in fish fed with a 30 mg Zn kg-1 diet. Zn contents in bone and muscle linearly increased up to 30 mg kg-1 Zn and then remained stable, while iron (Fe) and copper (Cu) contents in bone and muscle had an inverse pattern with the inclusion level of dietary Zn. Increasing dietary Zn levels up to 30 mg kg-1 was found to improve values of hematological parameters such as red blood cell (RBC), white blood cell (WBC), haemoglobin (Hb), and haematocrit (HCT). These values, however, decreased when the dietary Zn level was further increased. The serum alkaline phosphatase level was the highest in fish fed a diet containing 30 mg kg-1 of Zn. Regression analyses based on weight gain, specific growth rate, and bone and muscle Zn concentrations indicated that the optimum dietary Zn requirement for stinging catfish was in a range of 27.4-36.5 mg kg-1.

Feather meal processing methods impact the production parameters, blood biochemical indices, gut function, and hepatic enzyme activity in broilers.

This study investigated the effects of feather meal (FM) processing methods on production parameters, blood biochemical indices, intestinal morphology, digestive and hepatic enzyme activities, and gastrointestinal tract pH and microflora of broilers. A total of 480-d-old male broilers were used for 42 d in a completely randomized design with eight treatments and five replicates (12 chicks/replicate). Treatments were 1) a control diet (without FM), 2) a diet containing 4% raw FM (RFM), 3) a diet containing 4% processed FM (PFM) by autoclave (Au-PFM), 4) a diet containing 4% fermented FM (FFM) by Bacillus licheniformis (Bl-FFM), 5) a diet containing 4% FFM by Bacillus subtilis (Bs-FFM), 6) a diet containing 4% FFM by Aspergillus niger (An-FFM), 7) a diet containing 4% FFM by B. licheniformis + B. subtilis + A. niger (Co-FFM), and 8) a diet containing 4% PFM by an enzyme (En-PFM). Results showed that in the FFMs the contents of ash, ether extract, total volatile nitrogen, and amino acids including Lys, Met, Thr, Trp, His, Leu, Gly, Ile, Phe, and Tyr increased (P < 0.05), while crude fiber, crude protein, and dry matter content decreased (P < 0.05). Compared with the control, the Co-FFM diet had no significant differences (P > 0.05) in total body weight gain (2,827 vs. 2,791 g/chick), total feed intake (5,018 vs. 4,991 g/chick), European production efficiency factor (375 vs. 377), European Broiler Index (371 vs. 371), and feed conversion ratio (1.77 vs. 1.78 g/g). Feeding FFM decreased (P < 0.05) serum total cholesterol (1.46-fold), triglyceride (1.61-fold), very low-density lipoprotein cholesterol (1.61-fold), and low-density lipoprotein cholesterol (2.27-fold) compared to the control. Also, FFM increased (P < 0.05) villus height (1,045 to 1,351, 661 to 854, and 523 to 620 µm), and villus height to crypt depth ratio (6.15 to 8.45, 4.55 to 7.04, and 4.27 to 5.45), in the duodenum, jejunum, and ileum, respectively, compared to the control. Compared to the control, the Co-FFM diet increased (P < 0.05) protease (34, 39, and 45 %) in the pancreas, duodenum, and jejunum, as well as amylase (73, and 97 %) activities in the duodenum, and jejunum, respectively. Diets containing FFM reduced (P < 0.05) pH in the crop, gizzard, and ileum, and decreased (P < 0.05) Escherichia coli (6.12 to 5.70) count in ileum compared to the control. The Co-FFM diet increased (P < 0.05) lactic acid bacteria count in crop (6.77 to 7.50) and ileum (6.94 to 7.73), also decreased (P < 0.05) coliforms (6.31 to 5.75) count in ileum compared to the control. In conclusion, FM fermentation, particularly Co-FFM, improves the nutritional value of FM, converting it into a decent source of dietary protein for broilers.

Fermentation represents an attractive alternative method for feather meal (FM) efficient bioconversion and its nutritional value enhancement. This study investigated the effects of FM processing methods on broilers. Experimental diets were 1) a control diet (without FM), 2) a diet containing 4% raw FM (RFM), 3) a diet containing 4% processed FM (PFM) by autoclave (Au-PFM), 4) a diet containing 4% fermented FM (FFM) by Bacillus licheniformis (Bl-FFM), 5) a diet containing 4% FFM by Bacillus subtilis (Bs-FFM), 6) a diet containing 4% FFM by Aspergillus niger (An-FFM), 7) a diet containing 4% FFM by B. licheniformis + B. subtilis + A. niger (Co-FFM), and 8) a diet containing 4% PFM by an enzyme (En-PFM). Results showed that FFMs increased the contents of ash, ether extract, total volatile nitrogen, and amino acids including Lys, Met, Thr, Trp, His, Leu, Gly, Ile, Phe, and Tyr, while decreased crude fiber, crude protein, and dry matter content. The production parameters of birds fed Co-FFM were similar to the control group. In addition, FFMs decreased serum total cholesterol (1.46-fold), triglyceride (1.61-fold), very low-density lipoprotein cholesterol (1.61-fold), and low-density lipoprotein cholesterol (2.27-fold). Furthermore, Co-FFM improved intestinal morphology, enzyme activities, and beneficial bacterial populations. In conclusion, Co-FFM, improves the nutritional value of FM, converting it into a decent source of dietary protein for broilers.

Performance Evaluation of a Novel Combination of Four- and Five-Carbon [Butyric and Valeric] Short-Chain Fatty Acid Glyceride Esters in Broilers.

A novel combination of Butyric and Valeric acid glycerol esters with oregano oil in a dry powder form was evaluated for performance improvements in broilers. The dosing regimen (500 g/Ton feed in starter and grower; 250 g/Ton in finisher feed) was considered low compared to conventional practices using non-esterified Butyric and Valeric short-chain fatty acids (SCFA). Six trials were conducted at various trial facilities in Italy, United Kingdom, Spain, and Poland. Supplemented broilers weighed significantly more than the control birds at 28 days of age (+3.4%; 1459 g vs. 1412 g; p = 0.0006) and at 42 days of age (+2.5%; 2834 g vs. 2763 g; p = 0.0030). Supplementation significantly reduced mortality from 1.9% to 0.8% during the finisher phase (from 29 to 42 days of age); however, average mortality was 3.2% for the whole 42-day growth period and was not affected. Further, supplemented broilers grew more (66.4 vs. 64.5 g/day; p = 0.0005), ate more feed (104.7 vs. 103.1 g/day; p = 0.0473), converted feed significantly more efficiently (1.58 vs. 1.60; p = 0.0072), leading to better EPEF value (410 vs. 389; p = 0.0006) than the control broilers. Meta-analysed trial performance data for novel SCFA formulations such as these are not commonly available, and serve to facilitate efficacy determination from an end-user perspective. The use of short- and medium-chain fatty acid esters in optimal low-dose combinations to reliably augment gut health and performance appears promising in commercial broiler production, and may lead to further improvements in industry practices and reduced antibiotic use.

The effects of herbal plant extract on the growth performance, blood parameters, nutrient digestibility and carcase quality of rabbits: A meta-analysis.

A meta-analysis was conducted to determine the effects of herbal plant extracts on the growth performance, blood parameters, nutrient digestibility and carcase quality of farmed rabbits. A dataset was created from 33 in vivo studies comprising 121 experimental units. Statistical meta-analysis was performed using a random-effects model and linear-mixed model meta-regression using R software (v. 4.3.0). Our results showed that although supplemental herbs did not affect average daily gain (ADG) and final body weight (BW), they reduced (P < 0.01) feed conversion ratio and mortality and increased the digestibility of dry matter (DM) (P = 0.014) and crude protein (CP) (P = 0.018). The herbal extracts also increased (P = 0.037) blood high-density lipoprotein (HDL) and decreased (P = 0.004) low-density lipoprotein (LDL). Immunoglobulin M (IgM) was elevated (P = 0.009) by herbal plant extract supplementation, although most blood components were unaffected. The inclusion of herbal plant extract up to 300 g/kg increased (P = 0.011) carcase percentage while the weight and percentage of other organs were unaffected. Subgroup meta-analysis further explained the different effect of the type of herbal plant extract. Moringa, olive oil, and pepper were more favourable to increase final BW compared to the other herbs. Interestingly, the majority of herbs showed efficacy in reducing mortality. A majority of the response variables in our meta-analysis showed no dose-response effect except for ADG, mortality, HDL, and LDL which were improved by herbs supplementation. The evidence from the perspective of both meta-analysis and meta-regression shows that the addition of herbs tends to positively affect the parameters for production performance and blood metabolites in farmed rabbits.

The effect of humate as a feed additive on feed intake, production, and carcass parameters of Angus steers.

Humate may be a valuable livestock feed additive, with potential effects on nutrient utilisation and animal performance. Thus, the aim of this study was to investigate the effect of K Humate S 100R supplementation on the feed intake, liveweight gain, and carcass parameters of Angus steers. Within individual pens, 40 weaned steers were allocated to four treatment groups (n = 10/potassium humate K Humate S100R, Omnia Specialities Australia) for 100 days. The treatment groups included Group 1, 35 g K Humate S100R/animal/day; Group 2, 70 g K Humate S100R/animal/day; Group 3, 140 g K Humate S100R/animal/day; and Control Group, which were not supplemented with K Humate S100R (0 g K Humate S100R/animal/day). Chemical and mineral composition of the feed ingredients, dry matter intake (DMI), and average daily weight gains were recorded. The steers were slaughtered as a single group at a commercial Australian abattoir. Standard measures for hot standard carcass weight, eye muscle area, fat depth and coverage, marbling, ossification, meat and fat colour, dressing percentage and loin pH values at 24-hour postmortem were recorded. It was found that the steers allocated to Group 2 had higher DMI (P = 0.003) and feed conversion ratio (FCR) (P < 0.001) compared with those allocated to Group 1 and the Control Group. The MSA marbling score was lowest for steers allocated to the Control Group (P < 0.05) and comparable for those allocated to Groups 1, 2, and 3. Together, these results demonstrate that increased levels of K Humate S100R supplementation improved the carcass quality, via an increase in MSA. However, further research is warranted on the potential effects of humates supplementation on intramuscular fat associated qualities of beef.

Effects of pH and temperature on striped catfish Pangasianodon hypophthalmus juvenile: Data on growth performance and survival rate.

The growth performance and survival rates of juvenile striped catfish, Pangasianodon hypophthalmus, reared at various levels of pH and temperature were described in this article. Two rearing trials were conducted separately for pH and temperature where both trials lasted for 35 days. One hundred and twenty juveniles (1.5 ± 0.23 g) were randomly stocked into 12 rectangle glass aquariums (n = 10 fish/tank; three replicates per treatment) with 100 L of water for each trial. The treatment consisted of four different pH level (7.5, 8.0, 8.5 and 9.0) and four different temperature level (26 °C, 28 °C, 30 °C and 32 °C). The survival of fish was counted at the end of experiments, and the weight of the juvenile was measured once a week. The quantification of feed intake was determined through the measurement of the residual weight of the feeds after the feeding process. Upon the conclusion of the experiment, the data pertaining to weight and feed intake were utilized to calculate the specific growth rate (SGR) and food conversion ratio (FCR) as indicators of growth performance. Additionally, the number of live fish was employed to ascertain the survival rate. The data obtained from the calculation of SGR, FCR and survival rate were next subjected to a normality test, one-way analysis of variance (ANOVA), and a Tukey post-hoc test. The information in this article will help in the business, experimental, and personal usage for P. hypophthalmus juveniles rearing process.

Effects of feeding silage of beet pulp or maize on the growth performance, meat quality, and production economics of broiler ducks.

The present study aimed to compare the growth, meat quality, and production economics of Cherry Valley broiler ducks fed with a commercial diet along with silage from beet pulp or maize. In this study, 180 male Cherry Valley ducks were reared for 49 d. The control group (group C) was fed a commercial diet ad libitum. The experimental groups were fed a restricted amount of commercial diet and ad libitum beet pulp silage (group B) or maize silage (group M). For all groups, the growth performance and meat quality were analyzed, and their production costs were estimated. The beneficial effects of feeding maize silage on the growth rate were observed on d 29 to 49 in group M; moreover, both experimental groups showed lower feed intake than group C (P < 0.05). The feed conversion ratio was lower in the first rearing stage and during the entire experimental period in groups B and M than that in group C. Group M showed a higher European Production Efficiency Factor and European Broiler Index than group C (P < 0.05). The relative weight of the liver was higher in group C than that in the experimental groups (P < 0.05). Group M showed a higher L* value of leg muscles than group C (P < 0.05). Water-holding capacity was higher in leg muscles from ducks fed with silages (P < 0.05). The experimental groups had lower costs of commercial diets. Higher costs were observed for maize silage than for beet pulp silage. Carcass sales yielded the highest profit for group M and the lowest one for group C. Compared with the control group, the silage-fed groups showed a higher estimated profit by PLN 7.94 to 10.68 per duck (P < 0.05). Based on the beneficial production results, notably lower feed conversion ratio, no negative effects on carcass characteristics, and lower production costs, especially maize or even beet pulp silage in broiler duck rearing, could be recommended.

Trehalose Supplementation Effects on Growth, Intestinal Morphology, Gut Bacteria, and Footpad Dermatitis of Broiler Chickens Reared at High Density.

This study aimed to measure the effects of trehalose (Tre) supplementation on the growth, intestinal morphology, gut bacteria, and footpad dermatitis (FPD) of broiler chickens reared at different stocking densities (SD). Four hundred newly hatched Ross 308 male chicks were randomly allocated to four groups of eight, following a 2 × 2 factorial arrangement in a randomized complete block design using two SDs (normal, 11; high, 14 birds/m2) and two diets: basal with and without 0.5% Tre. Tre supplementation was provided during the starter/grower phase, but not the finisher phase. Data were analyzed using a two-way analysis of variance. We observed no significant effects of SD or Tre, individually or combined, on body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) during the starter/grower period. However, high SD decreased both BWG (P < 0.001) and FI (P < 0.05), and increased FCR (P < 0.001), during the finisher period. Whereas Tre reduced FCR (P < 0.05) as a main effect, no combined effect was observed on FCR. Over the total period, high SD negatively affected BWG and FCR (P < 0.001), and Tre significantly reduced FCR, with its effect unaffected by SD. No significant effects of SD or Tre were observed on jejunal morphology. The ileal abundance of Clostridium perfringens (P > 0.05) was not affected by high SD but was significantly reduced by Tre. Neither high SD nor Tre altered Lactobacillus spp. counts; however, high SD increased FPD lesion scores, whereas Tre had no effect. The study showed that Tre supplementation during the starter/grower period improved FCR during the finisher period, possibly by decreasing the abundance of C. perfringens in broiler chickens.

Dietary phosphorus requirement of silver CARP (Hypophthalmichthys molitrix) fingerlings.

The aim of this study was to determine the optimal dietary phosphorus (P) requirement and its effects on growth performance, body composition, mineralization and alkaline phosphate (ALP) activity in silver carp (Hypophthalmichthys molitrix). A total of 360 fish with an average initial weight of 7.0 ± 0.15 g were divided into 18 tanks (70 L capacity each) with a stocking density of 20 fish per tank in triplicate. The fish were fed diets containing six levels of P (3.3, 4.4, 5.5, 6.5, 7.5 and 8.6 g/kg) up to satiation for 90 days twice daily at 09:00 and 16:00. The results showed that fish fed diets containing 6.5 and 7.5 g/kg dietary P had significantly higher (p < 0.05) growth performance in terms of final weight gain, average weight gain (AWG), weight gain% (WG%), protein efficiency ratio (PER) and specific growth rate (SGR) than fish fed other diets. The best value of the feed conversion ratio (FCR) was observed in fish fed the 6.5 g/kg P diet, which was not significantly different from the 7.5 g/kg P diet. Increasing P supplementation above 6.5 g/kg significantly reduced (p < 0.05) the feed intake of silver carp. Whole-body composition analysis indicated that increasing P levels resulted in a decrease (p < 0.05) in crude fat (CF) and an increase (p < 0.05) in crude ash (CA) content, while crude protein (CP) and moisture content remained unaffected (p > 0.05). Fish fed diets containing ≥6.5 g/kg P had significantly higher (p < 0.05) Ca content in the whole body, bones and scales compared to those fed diets containing ≤5.5 g/kg P. A similar trend was observed for P and Mg contents in the whole body, bones and scales. The Zn content tended to decrease (p < 0.05) with increasing P supplementation in the whole body and bones, but fish fed diets containing ≥6.5 g/kg P had significantly higher (p < 0.05) Zn content compared to fish fed diets containing ≤5.5 g/kg P. The Ca/P ratio was significantly affected by P supplementation. Fish fed diets containing ≥6.5 g/kg P had significantly higher (p < 0.05) Ca and P contents in the serum than fish fed other diets. ALP activity increased (p < 0.05) with increasing P levels up to 6.5 g/kg P and decreased (p < 0.05) thereafter. In conclusion, supplementing P up to 6.35 g/kg is recommended for the optimal growth of silver carp.

Effects of antibiotic, acidifier, and probiotic supplementation on mortality rates, lipoprotein profile, and carcass traits of broiler chickens.

Antimicrobial resistance is a significant issue, therefore it's relevant to assess the effects of antibiotics, acidifiers, and probiotic supplementation finding a good alternative to reduce the use of antibiotics in broiler production in rural areas of Bangladesh. Using randomized control trial, this 28-day study evaluated 360 Hubbard Classic broiler chicks divided into four groups: oxytetracycline-treated, acidifier-treated, Lactobacillus-based probiotic-treated, and control (no antibiotics, acidifiers, or probiotics). Each group was replicated three times with 30 birds each with adlibitum feeding. Body weight and feed intake were recorded weekly, and on 28th day, carcass traits and blood lipoprotein levels were evaluated. Results showed that in first and fourth weeks, the body weight gain significantly varied in probiotics and acidifier-treated birds than the control group (P < 0.001). The probiotic group had gained considerable increase in body weight (185.0 g vs 161.7 g and 1745.0 g vs 1592.7 g) than the control group. Notably, in the first week, the feed conversion ratio for the probiotic group was 0.76, but the antibiotic group's was 0.96 (P < 0.001). The weights of the drumstick (88.33 g) and liver (61.0 g) having probiotic supplements were substantially higher than those in the control group (77.0 g and 51.33 g, respectively) (P < 0.001). According to serum lipoprotein analysis, the probiotic and acidifier groups exhibited lower LDL levels (71.1 mg/dl and 69.8 mg/dl, respectively) and higher triglyceride levels (122.9 mg/dl and 135.4 mg/dl). These findings highlight the potential of probiotics and acidifiers as effective antibiotic alternatives, promoting carcass traits and lowering LDL levels in broilers in Bangladesh.

Feed-food and land use competition of lowland and mountain dairy cow farms.

Dairy cows and other ruminants contribute to human nutrition as they are able to convert feed components containing human inedible fibre concentrations (e.g. roughage and by-products from the food processing industry) into valuable animal-sourced food. A number of crops often fed to dairy cows (e.g. soy or cereals) are however potentially edible by humans too. Additionally, land used to grow dairy cattle feed may compete with crop production for human consumption. Two different methods to assess the competition between feed consumption of dairy cows and human food supply were thus refined and tested on 25 Swiss dairy farms. With respect to the potential human edibility of the feeds used in dairy production, the human-edible feed conversion ratio (eFCR) was applied. The land use ratio (LUR) was used to relate the food production potential, per area of land utilised, with the dairy production output. Low to medium eFCR, with values ranging from 0.02 to 0.68 were found, as an average proportion of 0.74 of total DM intake consisted of roughage. In contrast, we found relatively high LUR (0.69-5.93) for most farms. If the land area used to produce feed for cows was used for crop production (applying a crop rotation), 23 of the 25 farms could have produced more edible protein and all farms more human-edible energy. Indicator values strongly depend on the underlying scenarios, such as the human-edible proportion of feeds or the suitability of land and climate for crop production. Reducing the amount of human-edible feeds in dairy farming by feeding by-products from the food processing industry and improving forage quality may be suitable strategies to reduce eFCR, but relying on low-opportunity cost feeds may restrict milk performance level per cow. On farm level, improving overall efficiency and therefore using less land (especially area suitable for crop production) per kg product decreases LUR. However, the most promising strategy to mitigate land use competition may be to localise dairy production to land areas not suitable for crop production. Both methods (eFCR and LUR) should be used in parallel. They offer an opportunity to holistically evaluate the net contribution of dairy production to the human food supply under different environmental conditions and stress the importance of production systems well suited to specific farm site characteristics.

Effects of Zinc-Gluconate Levels on Growth Performance, Whole-Body Composition, and Mineral and Enzyme Activities of Juvenile Mori (Cirrhinus mrigala).

Zinc (Zn) is an important dietary nutrient for the optimum growth performance, feed efficiency, normal metabolism, and fish health. Unfortunately, Zn requirement for mori (Cirrhinus mrigala) is not available. This experiment was designed to assess the impacts of Zn-gluconate levels on growth performance, feed utilization, mineral composition, and enzyme activities of mori and determines the optimum requirement of Zn-gluconate for this species. For this purpose, seven isonitrogenous (29.18%) and isolipidic (10.71%) purified diets were formulated with graded Zn-gluconate levels (0, 10, 20, 30, 40, 50, and 60 mg/kg). A total of 525 juveniles (4.30 ± 0.13 g) were distributed in 21 tanks. All treatments were assessed in triplicates. At the end of the trial (90 days), a progressive increase in final weight (FW) was observed in mori fed with 0-40 mg/kg of Zn-gluconate, remained constant at 50 mg/kg of Zn-gluconate, and significantly decreased at 60 mg/kg of Zn-gluconate. Similarly, weight gain and specific growth rate followed a similar pattern, while weight gain% increased till 40 mg/kg of Zn-gluconate. However, further increase (40-60 mg/kg) had a non-significant effect on weight gain%. Diet supplemented with 40 mg/kg of Zn-gluconate resulted in optimum values for feed intake and feed conversion ratio. Supplementation of Zn-gluconate did not affect dry matter, crude fat, and crude ash at all graded levels. However, whole body crude protein was significant in response to Zn-gluconate supplementation. Furthermore, Zn-gluconate absorption enhanced from 0 to 40 mg/kg of Zn-gluconate and remained constant afterward. Whole body mineral activity also followed a similar pattern. Overall, Zn-gluconate supplementation enhanced (P < 0.05) mineral activity in all parts of the tested parts of mori, including bones, scales, skin, eyes, heart, liver, and kidney. Moreover, the highest (P < 0.05) mineral activity in the skin, heart, liver, and kidney was observed in 60 mg/kg of Zn-gluconate. Supplementation of Zn-gluconate significantly increased the activity of alkaline phosphatase while it reduced thiobarbituric acid reactive substance contents of mori. The optimal dietary requirement of Zn-gluconate was recorded as 43.86 mg/kg through broken-line regression for maximum weight gain% of mori juveniles. Conclusively, 40 mg/kg of Zn-gluconate supplementation significantly enhanced the health of C. mrigala. However, a further increase in Zn-gluconate supplementation from 40 to 60 mg/kg did not significantly improve the above-mentioned parameters.

Effect of Lactic Acid and pH of Probiotic Yogurt on Peak Production of Laying Hens.

<b>Background and Objective:</b> Probiotic yogurt is beneficial for laying hens because it can improve the animal's hematological status which will improve livestock health, therefore it is hoped that probiotic yogurt can increase the production of laying hens. This research was conducted to determine the lactic acid levels and pH of probiotic yogurt, probiotic yogurt's effect on feed conversion ratio and total production of laying hens. <b>Materials and Methods:</b> The research was carried out using experimental methods using a Completely Randomized Design (CRD) with 5 treatments and 8 replications so the total sample was 40. The treatment consisted of P0: Basal ration; P1: Basal diet+2% probiotic powder B1 (<i>Bifidobacterium</i> spp. and <i>L. acidophilus</i>), P2: Basal ration+3% probiotic powder B1, P3: Basal diet+2% probiotic powder B2 (<i>L. bulgaricus</i>, <i>S. thermophilus</i>, <i>L. acidophilus</i> and <i>B. bifidum</i>) and P4: Basal ration+3% probiotic powder B2. The data were analyzed using Analysis of Variance (ANOVA) and followed by Duncan's Multiple Range Test. <b>Results:</b> Lactic acid content in probiotic yogurts B1 is 0.945% and B2 is 0.638%. Based on the results of statistical analysis using the variance test, show that giving probiotic powder to laying hens has a significant effect on the feed conversion ratio and has no significant effect on the production of laying hens. <b>Conclusion:</b> Based on the results of statistical analysis using the variance test, it shows that giving probiotic powder to laying hens has no significant effect on the production of laying hens during the peak period.

Identification of intestinal and fecal microbial biomarkers using a porcine social stress model.

Understanding the relationships between social stress and the gastrointestinal microbiota, and how they influence host health and performance is expected to have many scientific and commercial implementations in different species, including identification and improvement of challenges to animal welfare and health. In particular, the study of the stress impact on the gastrointestinal microbiota of pigs may be of interest as a model for human health. A porcine stress model based on repeated regrouping and reduced space allowance during the last 4 weeks of the finishing period was developed to identify stress-induced changes in the gut microbiome composition. The application of the porcine stress model resulted in a significant increase in salivary cortisol concentration over the course of the trial and decreased growth performance and appetite. The applied social stress resulted in 32 bacteria being either enriched (13) or depleted (19) in the intestine and feces. Fecal samples showed a greater number of microbial genera influenced by stress than caecum or colon samples. Our trial revealed that the opportunistic pathogens Treponema and Clostridium were enriched in colonic and fecal samples from stressed pigs. Additionally, genera such as Streptococcus, Parabacteroides, Desulfovibrio, Terrisporobacter, Marvinbryantia, and Romboutsia were found to be enriched in response to social stress. In contrast, the genera Prevotella, Faecalibacterium, Butyricicoccus, Dialister, Alloprevotella, Megasphaera, and Mitsuokella were depleted. These depleted bacteria are of great interest because they synthesize metabolites [e.g., short-chain fatty acids (SCFA), in particular, butyrate] showing beneficial health benefits due to inhibitory effects on pathogenic bacteria in different animal species. Of particular interest are Dialister and Faecalibacterium, as their depletion was identified in a human study to be associated with inferior quality of life and depression. We also revealed that some pigs were more susceptible to pathogens as indicated by large enrichments of opportunistic pathogens of Clostridium, Treponema, Streptococcus and Campylobacter. Generally, our results provide further evidence for the microbiota-gut-brain axis as indicated by an increase in cortisol concentration due to social stress regulated by the hypothalamic-pituitary-adrenal axis, and a change in microbiota composition, particularly of bacteria known to be associated with pathogenicity and mental health diseases.

Effects of Silage Type and Feeding Intensity on Carcass Traits and Meat Quality of Finishing Holstein-Friesian Bulls.

The study aimed at evaluating the influence of silage type (grass silage-GS, and maize silage-MS) and energy level in the feed portion on animals' performance, carcass value and the quality of Holstein-Friesian bull meat. The animals were reared using intensive (I) feeding, 1.02 feed units for meat production (UFV)/kg dry matter (DM), and semi-intensive (SI) feeding, 0.94 UFV/kg DM. Thirty-two HF bulls with an average live weight of 530 kg were assigned to four feeding groups. The proportions (g/kg DM) of feed in the diets were as follows: group GS-I, GS 500, concentrate 500; group GS-SI, GS 700, concentrate 300; group MS-I, MS 500, concentrate 500; and group MS-SI, MS 700, concentrate 300. After 4 months of the finishing phase, bulls were slaughtered and samples of the longissimus lumborum muscle were collected. The silage type did not affect performance, carcass value or meat quality. However, in the intensive feeding, a 33% increase (p < 0.01) in daily weight gain and a reduction in the feed conversion ratio compared to semi-intensive feeding were noted. The carcasses of bulls fed intensively received higher scores for conformation and fatness than the carcasses of bulls fed semi-intensively. The meat of I group bulls had a higher intramuscular fat content and received higher juiciness, tenderness, taste and overall acceptability scores.

Effect of Diet Supplementation with Oat Hay and Whole Carrot on Rabbit Growth and Productive Efficiency.

Is it possible to reduce feeding costs in rabbit meat production without compromising rabbit health and productive yield? The study tested four feeding strategies: Control group (CC) fed exclusively with concentrate feed; group CT supplemented with whole carrot; group OH supplemented with oat hay; and Group CO supplemented with oat hay and whole carrot. Each feeding strategy was tested in 20 rabbits, randomly allocated in five cages with four rabbits each. The average daily weight gain (ADG), feed conversion ratio (FCR), and the amount of concentrated feed consumed daily were estimated in all experimental groups. Group CC displayed the best ADG (37.1 g/rabbit/day), carrot had no significant influence on ADG (34.2 g/rabbit/day), but oat hay had a negative impact (p < 0.05), either used alone or in combination with carrot (33.0 and 32.6 g/rabbit/day, respectively). Supplementation with carrot, oat hay, or both increased the FCR (p < 0.001). Nevertheless, there were no significant differences in final live weight or carcass weight between the rabbits in the different experimental groups. In conclusion, supplementation with oat hay, carrot, or both can be a valid approach to reducing production costs by decreasing concentrate feed without affecting rabbit's health and meat yield. The combined supplementation with oat hay and carrot proved to be the best option in reducing the amount of concentrate feed ingested by rabbits (less than 1107 g/animal), but at current market values, supplementation exclusively with oat hay was the less expensive feeding strategy (less 14% than fed exclusively with concentrate feeding).

Relationship between hindgut microbes and feed conversion ratio in Hu sheep and microbial longitudinal development.

Feed efficiency is an important indicator in the sheep production process, which plays an important role in improving economic benefits and strengthening energy conservation and emission reduction. Compared with the rumen, the fermentation of the hindgut microorganisms can also provide part of the energy for the host, and the composition of the hindgut microorganisms will affect the feed efficiency. Therefore, we hope to find new ways to regulate sheep feed efficiency by studying the sheep gut microbes. In this study, male Hu sheep with the same birth date were raised under the same conditions until 180 d old. The sheep were divided into high and low groups according to the feed conversion ratio (FCR) at 80 to 180 d old, and the differences in rectal microorganisms between the two groups were compared. The permutational multivariate analysis (PERMANOVA) test showed that there were differences in microorganisms between the two groups (P < 0.05). Combined with linear fitting analysis, a total of six biomarkers were identified, including Ruminobacter, Eubacterium_xylanophilum_group, Romboutsia, etc. Functional enrichment analysis showed that microorganisms may affect FCR through volatile fatty acids synthesis and inflammatory response. At the same time, we conducted a longitudinal analysis of the hindgut microbes, sampling nine-time points throughout the sheep birth to market stages. The microbiota is clearly divided into two parts: before weaning and after weaning, and after weaning microbes are less affected by before weaning microbial composition.

The level of feed efficiency determines the input of sheep production costs and the income of economic benefits. Improving sheep feed efficiency can effectively save energy and reduce emissions. Gut microbes play an important role in the process of feed fermentation. In this study, biomarkers associated with feed efficiency were identified by exploring the relationship between microbes and feed conversion ratio. At the same time, the longitudinal development of microorganisms was explored. It provides a basis for the regulation of intestinal microbes in sheep.

Effect of Dietary Gelsemium elegans Benth. Extract on the Growth, Slaughter Performance, Meat Quality, Intestinal Morphology, and Microflora of Yellow-Feathered Chickens.

The plant species Gelsemium elegans Benth. (GEB) promotes pig and sheep growth; however, little is known about its effects in chickens. In this study, a GEB extract (GEBE) was prepared, and its effects on the growth, slaughter, antioxidant performance, meat quality, serum biochemical indices, intestinal morphology, and microflora of yellow-feathered chickens were evaluated. In total, 600 chickens aged 15 days were randomly divided into four groups with five replicates each and fed a basal diet containing 0% (control), 0.25% (0.25 GEBE), 0.75% (0.75 GEBE), or 1.25% (1.25 GEBE) GEBE until 49 days of age. Chickens were then killed, and their meat, organs, and serum and cecal contents were collected. GEBE reduced the feed conversion ratio, particularly in the 0.75 and 1.25 GEBE groups. Furthermore, the GEBE diet improved meat tenderness and reduced the meat expressible moisture content and liver malondialdehyde content, indicating high meat quality. Whereas the 0.25 GEBE diet increased the level of Lactobacillus acidophilus in the cecum, the 0.75 GEBE diet decreased the Escherichia coli level therein. These findings demonstrate that GEBE may improve the meat quality and cecal microbiota of yellow-feathered chickens, providing a basis for identifying candidate alternatives to conventional antibiotics as growth promoting feed additives.

Determining and predicting feed intake in crossbred sheep from weaning until maturity.

Access to simple, accurate feed intake models would facilitate decision-making in feedlots as feed costs are a major part of operational expenditure. This study aimed to develop genotype-specific feed intake models for South African feedlot lambs. Four ram and four ewe lambs each of eight genotypes were raised under ideal growth conditions from weaning until 1 year of age. Feed intake and growth were monitored throughout this period. The intake data were then used to fit various models to predict daily feed intake, intake as percentage of body weight, cumulative intake and feed conversion ratio. No satisfactory univariate models could be found for the prediction of daily or percentage intake, but a good fit was found for cumulative intake data (R2 >0.80, P <0.01). The slope parameters of these linear models show a strong correlation (72%) with feed conversion and can therefore also serve as proxies for feed conversion. A model was also developed that can predict feed conversion ratio with a moderate accuracy (R2 =0.5, P <0.05) at a given body weight. The cumulative intake model was deemed accurate and simple enough for practical use.

Assessment of methionine plus cystine requirement of tambaqui (Colossoma macropomum) based on zootechnical performance, body composition, erythrogram, and plasmatic and hepatic metabolites.

Tambaqui (Colossoma macropomum) is a species of great cultural and economic importance in aquaculture in the Amazon region. Methionine is considered the first limiting sulfur amino acid in practical fish diets, which encourages investigating its use in diets for tambaqui. This study aimed to verify the digestible methionine plus cystine (Met + Cys) requirement in diets for tambaqui (89.52 ± 0.53 g) for 60 days. The treatments investigated were: 6.50, 7.80, 9.10, 10.40, 11.70, and 13.00 g Met + Cys kg diet-1. The estimated requirement based on final weight, weight gain, feed conversion ratio, and specific growth rate was 9.04, 8.92, 8.91, and 8.58 g Met + Cys kg diet-1, respectively, while on body protein deposition, body fat deposition, body ash deposition, and nitrogen retention efficiency was 9.29, 9.20, 9.19, and 8.72 g Met + Cys kg diet-1, respectively. Linear regression demonstrated that increased digestible Met + Cys in the diet decreased plasma total protein, globulin, and liver total protein levels. Quadratic regression showed that the highest value for liver glycogen was found with a 10.40 g Met + Cys kg diet-1. Another quadratic regression demonstrated a lower hepatic aspartate aminotransferase (AST) enzymatic activity in fish fed between 7.80 and 11.70 g Met + Cys kg diet-1. The different treatments did not influence the erythrogram. In conclusion, when considering an integrative view of the results for growth performance, whole-body deposition, and liver parameters without harming the physiological and metabolic status, we recommended choosing a diet with digestible Met + Cys between 8.58 and 9.29 g kg- 1 for tambaqui.