Novel insight into the feed conversion ratio in laying hens and construction of its prediction model.

Feed efficiency (FE) is an important economic factor in poultry production, and feed conversion ratio (FCR) is one of the most widely used measures of FE. Factors associated with FCR include genetics, the environment, and other factors. However, the mechanisms responsible for FCR in chickens are still less well appreciated. In this study, we examined the pattern changes of FCR, then delved into understanding the mechanisms behind these variations from both genetic and environmental perspectives. Most interestingly, the FCR at the front section of henhouse exhibited the lowest value. Further investigation revealed that laying rate in the high FCR (HFCR) group was lower than that in the low FCR (LFCR) group (P < 0.05). Cortisol, total antioxidant capacity (TAOC), and IgG levels in the LFCR group were significantly lower than those in the HFCR group (P < 0.05), while BUN level was significantly higher than that in the HFCR group (P < 0.05). We identified a total of 67 and 10 differentially expressed genes (DEGs) associated with FCR in ovarian and small intestine tissues, respectively. Functional enrichment analysis of DEGs revealed that they might affect FCR by modulating genes associated with salivary secretion, ferroptosis, and mineral absorption. Moreover, values for relative humidity (RH), air velocity (AV), PM2.5, ammonia (NH3), and carbon dioxide (CO2) in the LFCR group were significantly lower than those in the HFCR group (P < 0.05). Conversely, value for light intensity (LI) in the LFCR group was significantly higher than that in the HFCR group (P < 0.05). Correlation analysis revealed a positive correlation between FCR and RH, AV, PM2.5, NH3, and CO2, and a negative correlation with LI. Finally, the FCR prediction model was successfully constructed based on multiple environmental variables using the random forest algorithm, providing a valuable tool for predicting FCR in chickens.

Dietary supplementation of Cannabis sativa residues in broiler chickens affects performance, carcass characteristics, intestinal morphology, blood biochemistry profile and oxidative stability.

Public interest in the cannabis plant has increased after its legalization in many countries. Cannabis sativa residues (CR) are a part of the plant waste in the cannabis industry. The CR contain medicinal properties that could be used as a feed additive in poultry production. The trial was conducted to investigate the effects of CR on growth performance, carcass characteristics, intestinal morphology, and blood biochemistry profile of broiler chickens. In a completely randomized design, 256 one-day-old male Ross 308 broilers were randomly allocated to 4 treatments with 8 replicates and 8 birds per replicate. These 4 dietary treatments included a basal diet with 0, 0.5, 1 and 2% CR for 40 d. The results showed that 2% CR supplementation reduced feed intake (FI) in the starter phase (d 3-23, P < 0.05). The birds in the CR groups had lower FI in the finishing phase (d 24-40, P < 0.01) and the whole raising period (d 3-40, P < 0.01) than the control. However, the body weight and carcass yield were not different (P > 0.05). In addition, the CR diet had no adverse effects on the blood biochemistry profile, including total cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein, globulin, albumin, and direct bilirubin (P > 0.05). In addition, total bilirubin and malondialdehyde were better in the plasma of CR-supplemented birds than in the control groups (P < 0.05). The observations on intestinal morphology showed that CR supplementation improved the ratio between villus height and crypt depth in the ileum (P < 0.05). In conclusion, CR supplementation can improve intestinal morphology and oxidative stability of broiler chickens. This suggests that CR could potentially be used as an alternative feed additive in broiler production.

Performance, nutrient utilization and meat quality traits in Bos indicus cattle: a meta-analysis examining the effect of residual feed intake.

This meta-analysis aims to investigate the effects of residual feed intake (RFI) phenotype on performance, nutrient utilization and meat quality traits in Zebu (Bos indicus) cattle. Twenty-three peer-reviewed publications with 37 treatment means were included in the dataset. Weighted mean difference analysis compared animals categorized into low RFI (more efficient) versus medium or high RFI (less efficient) groups. Data heterogeneity via meta-regression and subgroup analysis, considering variables such as animal age, sex class, experimental duration, RFI group, dietary concentrate, and estimated metabolizable energy intake were also explored. The predominant genetic group of cattle in the dataset was Nellore (89.18%), followed by Brahman (10.81%). More efficient animals (low RFI phenotype) exhibited less dry matter intake (DMI; P < 0.010) than medium or high RFI animals (-0.95 kg vs. -0.42 kg/d). Cattle dietary crude protein and fiber digestibility were consistent across RFI groups (P > 0.05), while dietary ether extract digestibility tended to decrease (P = 0.050) in low RFI animals (-13.20 g/kg DM). Low RFI animals tended to increased (P = 0.065) ribeye area (REA) compared to the high/medium RFI groups, while carcass backfat thickness (BFT) decreased (P = 0.042) compared to high/medium RFI groups. Moreover, there was an increase (P < 0.001) of 0.22 kg in Warner-Bratzler shear force (WBSF) and a reduction (P < 0.001) in the myofibrillar fragmentation index (MFI) in low RFI animals. Meat color parameters (lightness [L*] and yellowness [b*]) and visual marbling scores were consistent (P > 0.05) across RFI groups. In conclusion, Zebu cattle classified as efficient (low RFI) exhibited reduced DMI, which improves their feed efficiency. However, BFT and meat quality parameters such as tenderness (WBSF and MFI) and redness [a*] were compromised by low RFI phenotype, highlighting the challenge of enhancing feed efficiency and meat quality traits in Zebu cattle.

Relationship between jejunum ATPase activity and antioxidant function on the growth performance, feed conversion efficiency, and jejunum microbiota in Hu sheep (Ovis aries).

BACKGROUND: ATPase activity and the antioxidant function of intestinal tissue can reflect intestinal cell metabolic activity and oxidative damage, which might be related to intestinal function. However, the specific influence of intestinal ATPase activity and antioxidant function on growth performance, feed conversion efficiency, and the intestinal microbiota in sheep remains unclear. RESULTS: This study analyzed the correlation between ATPase activity and antioxidant function in the jejunum of 92 Hu sheep and their growth performance and feed conversion efficiency. Additionally, individuals with the highest (H group) and lowest (L group) jejunum MDA content and Na+ K+-ATPase activity were further screened, and the effects of jejunum ATPase activity and MDA content on the morphology and microbial community of sheep intestines were analyzed. There was a significant correlation between jejunum ATPase and SOD activity and the initial weight of Hu sheep (P < 0.01). The H-MDA group exhibited significantly higher average daily gain (ADG) from 0 to 80 days old and higher body weight (BW) after 80 days. ATPase and SOD activities, and MDA levels correlated significantly and positively with heart weight. The jejunum crypt depth and circular muscle thickness in the H-ATP group were significantly higher than in the L-ATP group, and the villus length, crypt depth, and longitudinal muscle thickness in the H-MDA group were significantly higher than in the L-MDA group (P < 0.01). High ATPase activity and MDA content significantly reduced the jejunum microbial diversity, as indicated by the Chao1 index and observed species, and affected the relative abundance of specific taxa. Among species, the relative abundance of Olsenella umbonata was significantly higher in the H-MDA group than in the L-MDA group (P < 0.05), while Methanobrevibacter ruminantium abundance was significantly lower than in the L-MDA group (P < 0.05). In vitro culture experiments confirmed that MDA promoted the proliferation of Olsenella umbonata. Thus, ATPase and SOD activities in the jejunum tissues of Hu sheep are predominantly influenced by congenital factors, and lambs with higher birth weights exhibit lower Na+ K+-ATPase, Ca2+ Mg2+-ATPase, and SOD activities. CONCLUSIONS: The ATPase activity and antioxidant performance of intestinal tissue are closely related to growth performance, heart development, and intestinal tissue morphology. High ATPase activity and MDA content reduced the microbial diversity of intestinal tissue and affect the relative abundance of specific taxa, representing a potential interaction between the host and its intestinal microbiota.

Meta-Analyses of Methionine Source Concept Validation Trials in Broilers.

While the supplementation of methionine (Met) sources in broiler feeds has been established for several decades, there is debate on the nutritional value of the methionine hydroxy analogue of methionine (MHA) relative to DL-Met. Based on a recommendation suggesting that MHA is 65% as effective as DL-Met, many feeding trials have been conducted to challenge this recommendation. A literature search found 25 publications contributing 95 data sets suitable to compute Hedges' g effect sizes used in the meta-analysis. The data had very little heterogeneity of almost zero and the small effect sizes of the DL-Met results were not significantly different from MHA. Data were split in various subgroups, finally suggesting that neither broiler strain (Cobb 500, Ross 308), diet type (corn, wheat based), origin of data (peer-reviewed, grey literature), nor MHA product (MHA-free acid, MHA-calcium salt) impacted the outcome of the meta-analysis. Moreover, distinguishing data in groups with dietary Met+Cysteine (Cys) levels below, at, or above requirement demonstrated that there was no interaction with general Met+Cys supply. It is therefore concluded that MHA products can be replaced by DL-Met in a weight-to-weight ratio of 100:65 in any production condition without compromising broiler performance.

Assessing short-term feed efficiency and its association with biological markers in herbage-fed dairy cows.

Feed efficiency is an important trait of dairy production. However, assessing feed efficiency is constrained by the associated cost and difficulty in measuring individual feed intake, especially on pastures. The objective of this study was to investigate short-term feed efficiency traits of herbage-fed dairy cows and screening of potential biomarkers (n = 238). Derived feed efficiency traits were ratio-based (i.e., feed conversion ratio (FCR) and N use efficiency (NUE)) or residual-based (i.e., residual feed intake (RFI), residual energy intake (REI), and residual N intake (RNI)). Thirty-eight Holstein and 16 Swiss Fleckvieh dairy cows underwent a 7-d measurement period during mid- and/or late-lactation. The experimental data (n = 100 measurement points) covered different lactational and herbage-fed system situations: mid-lactation grazing (n = 56), late-lactation grazing (n = 28), and late-lactation barn feeding (n = 16). During each measuring period, the individual herbage intake of each cow was estimated using the n-alkane marker technique. For each cow, biomarkers representing milk constituents (n = 109), animal characteristics (n = 13), behaviour, and activity (n = 46), breath emissions (n = 3), blood constituents (n = 35), surface, and rectal temperature (n = 29), hair cortisol (n = 1), and near-infrared (NIR) spectra of faeces and milk (n = 2) were obtained. The relationships between biomarkers and efficiency traits were statistically analysed with univariate linear regression and for NIR spectra using partial least squares regression with feed efficiency traits. The feed efficiency traits were interrelated with each other (r: -0.57 to -0.86 and 0.49-0.81). The biomarkers showed varying R2 values in explaining the variability of feed efficiency traits (FCR: 0.00-0.66, NUE: 0.00-0.74, RFI: 0.00-0.56, REI: 0.00-0.69, RNI: 0.00-0.89). Overall, the feed efficiency traits were best explained by NIR spectral characteristics of milk and faeces (R2: 0.25-0.89). Biomarkers show potential for predicting feed efficiency in herbage-fed dairy cows. NIR spectra data analysis of milk and faeces presents a promising method for estimating individual feed efficiency upon further validation of prediction models. Future applications will depend on the ability to improve the robustness of biomarkers to predict feed efficiency in a greater variety of environments (locations), managing conditions, feeding systems, production intensities, and other aspects.

Effects of peppermint essential oil and artifier on growth performance, carcass characteristics and nutrient digestibilities in broiler chickens fed with low energy diets.

The aim of this experiment was to investigate the effects of peppermint essential oil (PEO) and an emulsifier called artifier on growth performance, carcass characteristics, and nutrient digestibility of broiler chickens fed low-energy diets. A total of 240 one-day-old male Ross 308 broiler chickens were divided into five treatments: control, low-energy diet, low-energy diet + 150 ppm PEO, low-energy diet + 300 ppm artifier, and low-energy diet + 150 ppm PEO + 300 ppm artifier. Each treatment was replicated four times in a completely randomized design. The chickens were fed these treatments during the starter, grower, and finisher periods for a total of 42 days. The results indicated that broiler chickens receiving the low-energy diet supplemented with PEO + artifier had similar body weight gain, feed conversion ratio, and breast percentage, but exhibited significantly lower abdominal fat percentage compared to those fed the control diet (P < 0.05). Furthermore, birds receiving PEO and artifier in low-energy diets, either individually or in combination, demonstrated higher digestibility of dry matter and fat during the starter and grower periods in comparison to those receiving the low-energy diet without any additives (P < 0.05). Over the entire rearing period, the simultaneous inclusion of 150 ppm PEO and 300 ppm artifier in the low-energy diet resulted in comparable growth performance to the control diet. Additionally, the concurrent use of PEO and artifier in the low-energy diet for broiler chickens led to a decrease in abdominal fat, increased digestibility of fat and dry matter, and enhanced nutrient utilization compared to the control diet.

Repeatability of feed efficiency and its relationship with carcass traits in Hanwoo steers during their entire growing and fattening period.

Objective: This study investigated the repeatability of feed efficiency and its association with carcass traits in Hanwoo steers during the entire growing and fattening periods. Methods: The growth and intake of thirty-six Hanwoo steers (259 ± 19.7 kg; nine months) were monitored throughout five periods, including two growing periods (GP) and three fattening periods (FP). The steers were fed two types of concentrate mixes with varying nutrient compositions until they reached a target weight of 800 kg for slaughter. For each period, steers were categorized into three classes based on their feed efficiency rankings using residual feed intake (RFI) and feed conversion ratio (FCR). Feed efficiency repeatability was assessed using the Spearman correlation coefficient, decomposition of random errors, and the Theil segregation index (TSI). The Pearson correlation coefficient was used to examine the relationship between feed efficiency and carcass traits. Results: The results demonstrated a significant and high correlation with RFI, but not FCR, during the growing or fattening stages (r > 0.5; P < 0.01). When steers were classified according to their feed efficiency rankings, 58% of the animals in the high RFI class (low efficient) initially (GP 1) remained in the same class by the last period (FP 3), whereas steers were randomly distributed based on FCR. The repeatability, assessed by the decomposition of random errors, was higher for RFI (0.61) than for FCR (0.15). The TSI also indicated that RFI rankings, rather than FCR rankings, are more likely to be maintained. Moreover, a weak association was observed between feed efficiency and carcass traits. Conclusion: In conclusion, RFI repeatability throughout the growing and fattening periods surpassed that of the FCR, with steers classified as high RFI during the GP more likely to remain in the same class during the FP. Feed efficiency was weakly correlated with carcass traits.

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.

Larval performance of Zophobas morio (F.) (Coleoptera: Tenebrionidae) on various diets enriched with post-distillation residues and essential oils of aromatic and medicinal plants.

The increasing demands for resources driven by the global population necessitate exploring sustainable alternatives for affordable animal protein over the use of traditional protein sources. Insects, with their high protein content, offer a promising solution, especially when reared on agricultural post-distillation residues for enhanced sustainability and cost-effectiveness. We assessed the development of Zophobas morio (F.) (Coleoptera: Tenebrionidae) larvae on diets enriched with essential oils and post-distillation residues from Greek aromatic and medicinal plants. Two aromatic plant mixtures (A and B) were examined. Mixture A consisted of post-distillation residues, while Mixture B incorporated these residues along with essential oils. Insect rearing diets were enriched with different proportions (10, 20, and 30 %) of these mixtures, with wheat bran serving as the control. Enrichment positively influenced larval development without compromising survival. Larval weight remained unchanged with Mixture A, but improved with Mixture B. No adverse effects were detected in the case of the enriched diets, although higher concentrations of Mixture B prolonged development time.

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.

Effect of stocking density on performance, survival and nutrient composition of super worm Zophobas Morio (Coleoptera:Tenebrionidae).

As the global demand for animal protein continues to increase, the need for sustainable and resource-efficient alternatives for animal feed becomes increasingly paramount. Insects have gained significant attention as promising candidates to support the sustainable development of the feed industry, and their utilization in animal feed has seen substantial growth in recent years. Therefore, this study was conducted to optimize the superworm (Zophobas morio) larvae rearing stocking density on the biomass production, survival, and nutrient composition. Two-weeks-old Z. morio larvae were maintained at 25 ± 2 oC and 70% relative humidity, and at densities of 0.5, 0.75, 1 and 1.25 cm2 space per larva, respectively. The insects reared with a density of 1.25 cm2 per larvae had higher feed intake (FI) and weight gain (WG) (P < 0.05). However, better feed conversion efficiency (FCE) was recorded with a density of 0.75 cm2 per larvae (P < 0.05). The survival significantly increased with increasing the density per larvae (P < 0.05). High survival of Z. morio larvae was recorded at density of 1 and 1.25 cm2 per larvae. The dry matter and fat contents of Z. morio larvae were higher at density of 0.5 cm2 per larvae (P < 0.05). However, the protein content was higher at density of 1 and 1.25 cm2 per larvae (P < 0.05). Moreover, the ash content was higher at 0.5, 0.75, and 1.25 cm2 per larvae (P < 0.05). This study highlights that Z. morio larvae rearing stocking density has a profound influence on growth performance, survival and its nutrient composition.

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.

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.

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.

Exome-informed formulations of food proteins enhance body growth and feed conversion efficiency in ad libitum-fed mice.

Meeting requirements for dietary proteins, especially of essential amino acids (EAAs), is critical for the life-long health of living organisms. However, defining EAA targets for preparing biologically-matched nutrition that satisfies metabolic requirements for protein remains challenging. Previous research has shown the advantages of 'exome matching' in representing the specific requirement of dietary AAs, where the target dietary AA profile was derived from in silico translation of the genome of an organism, specifically responsible for protein expression (the 'exome'). However, past studies have assessed these effects in only one sex, for few parameters (body mass and composition), and have used purified diets in which protein is supplied as a mixture of individual AAs. Here, for the first time, we utilise a computational method to guide the formulation of custom protein blends and test if exome matching can be achieved at the intact protein level, through blending standard protein ingredients, ultimately leading to optimal growth, longevity and reproductive function. Mice were provided ad libitum (ad lib) access to one of the four iso-energetic protein-limited diets, two matched and two mis-matched to the mouse exome target, and fed at a fixed protein energy level of 6.2%. During or following 13-weeks of feeding, the food intake, body growth, composition and reproductive functions were measured. Compared to the two mis-matched diets, male and female animals on the exome-matched diet with protein digestibility correction applied, exhibited significantly improved growth rates and final body mass. The feed conversion efficiency in the same diet was also increased by 62% and 40% over the worst diets for males and females, respectively. Male, not female, exhibited higher accretion of lean body mass with the matched, digestibility-corrected diet. All reproductive function measures in both sexes were comparable among diets, with the exception of testicular daily sperm production in males, which was higher in the two matched diets versus the mis-matched diets. The results collectively demonstrate the pronounced advantages of exome-matching in supporting body growth and improving feed conversion efficiency in both sexes. However, the potential impact of this approach in enhancing fertility needs further investigation.

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.