Meat Yield Research Articles

Effects of Glucose Concentration on Differentiation, Adipogenic Marker Genes Expression and Glucose Transporter Distribution in Bovine Subcutaneous Preadipocytes

Background: Fat deposition in beef cattle significantly influences both the meat yield of individual carcasses and the perceived eating quality for consumers. Glucose, as a crucial regulator, plays an essential role in the differentiation of bovine preadipocytes and lipid metabolism. This study aimed to investigate the effects of varying glucose concentrations (0, 3.0, 3.5 and 4.0 mmol/L) on the differentiation of bovine subcutaneous preadipocytes. Additionally, we explored the expression levels of key adipogenic marker genes and the distribution of glucose transporters during adipocyte differentiation. Methods: The differentiation of preadipocytes was assessed using Oil Red O staining and triacylglycerol content was quantified using a triglyceride assay kit. To evaluate the expression of adipogenic genes included peroxisome proliferator-activated receptor- γ (PPARγ), fatty acid synthase (FAS) and acetyl-CoA carboxylase 1 (ACC1), quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure mRNA levels, while protein levels were determined through western blotting. Additionally, the distribution of glucose transporters GLUT1 and GLUT4 during differentiation was analyzed through immunofluorescence. Result: The results showed that the differentiation of preadipocytes, along with the accumulation of lipid droplets, was enhanced at 2 and 4 days (p less than 0.05). However, this effect gradually diminished by day 8 as glucose concentration increased. During the early stages of preadipocyte differentiation, the expression of adipogenic marker genes-PPARγ, FASand ACC1-significantly increased at both the mRNA and protein levels (p less than 0.05, p less than 0.01). However, by day 8, as glucose concentration increased, a decreasing trend in the expression of these genes was observed. The fluorescence intensity of glucose transporters GLUT1 and GLUT4 rose significantly with higher glucose concentrations. These findings suggested that adding glucose at 3.0 to 3.5 mmol/L to the differentiation medium is optimal for promoting differentiation and fat deposition in bovine subcutaneous preadipocytes.

A PLIN1 polymorphism is associated with fat production in male emus

The emu (Dromaius novaehollandiae) is a novel poultry species that produces meat, eggs, and fat. Although emus have recently been domesticated, genetic improvements to establish strains have scarcely progressed. In this study, we investigated the relationship between production traits and perilipin 1-encoding gene (PLIN1) polymorphisms in the emus. We determined the partial complementary DNA (cDNA) sequence of the PLIN1, which is involved in lipid droplet formation. We identified four nucleotide substitution sites (c.270C>T, c.321T>C, c.587A>T, and c.639C>T) in the PLIN1 gene of emus. Of these, c.587A>T is a non-synonymous substitution that converts lysine to methionine at the 196th codon (p.K196M). Although p.K196M was predicted to affect the production traits of emus, a large deflection in genotype frequency was observed in this study; thus, we could not investigate the relationship between genotypes and phenotypes. In males, the fat yields of the CC, CT, and TT genotypes in c.270C>T were 0.25 ± 0.06, 0.22 ± 0.06, and 0.21 ± 0.07 kg, respectively, while the meat yields of the CC, CT, and TT genotypes in c.270C>T were 0.15 ± 0.01, 0.16 ± 0.02, and 0.16 ± 0.03 kg, respectively. These results indicate that male emus with the CC genotype had a significantly higher fat content and lower meat productivity than male emus with the other genotypes (P < 0.05). Therefore, c.270C>T in PLIN1 affects fat and meat production in males. Our findings may contribute to the effective genetic improvement of the emus.

Full-length transcriptome sequencing of the longissimus dorsi muscle of yak and cattle-yak using nanopore technology

Short-read RNA sequencing has been used to sequence the transcriptome of the skeletal muscle of yak and cattle-yak; however, full-length transcripts cannot be obtained and alternative splicing (AS) events cannot be inferred using this sequencing approach. Here, we used Oxford Nanopore Technologies (ONT) full-length sequencing to sequence the transcriptome of the longissimus dorsi of yak and cattle-yak. A total of 20,323 novel genes and 172,870 novel transcripts were identified, and 159,700 novel transcripts were successfully annotated. A total of 157,812 AS events, 58,073 simple sequence repeats, 57,468 complete open reading frames, 2296 transcription factors, and 20,404 lncRNAs were detected. Differentially expressed transcripts (DETs) in the longissimus dorsi muscle of yak and cattle-yak were involved in the MAPK and JAK-STAT signaling pathways related to muscle development and growth. Protein–protein interaction analysis of DETs suggested that TNNI2 might make a major contribution to differences in muscle growth and meat quality traits between yak and cattle-yak. The results have enriched the transcriptome data of dorsal muscles, providing new ideas for the study of transcriptional regulation processes, and also providing useful information for the production of higher yields of yak meat.

PIT1/HINFI POLYMORPHISM IN HOLSTEIN CATTLE IN AFYONKARAHISAR PROVINCE

Pit1 gene has been shown to be located on the centromeric region of chromosome 1 in cattle. This gene has responsible for development of pituitary gland and hormone expression in mammals. Pit1 deficiency causes a dwarfism phenotype in mice, dogs and fish. Previous studies has demonstrated to associated with polymorphisms of the Pit1 gene and growth and reproductive performance and milk, meat yield traits. In the cattle, a HinfI polymorphism on Pit1 gene (c.1178G&gt;A ) have been reported that there is an association between milk and reproduction yield parameters. In this study, we aimed existence and distribution of Pit1/HinfI polymorphism in 81 head of Holstein cattle in Afyonkarahisar province. In our study, we found that there were 5 AA, 30 AG and 46 GG genotypes in our survey population. We also detected to frequency of A allele as 0.25 and the G allele as 0.75. We calculated to genetic index values such as PIC (0.3027418) and Heterozygosity (0.3742044) using by RStudio package. Chi-square value was found 0.049 and was exhibited to survey population in Hardy-Weinberg equilibrium. Considering of these findings, we denoted proper of Pit1/HinfI polymorphism using in marker assisted selection studies both of native and culture cattle breeds.

Ocean Acidification and Sea Temperature Rise Affect the Queen Scallop Aequipecten opercularis (Linnaeus, 1758) in Captivity

Climate change poses risks to bivalves; thus, searching for resilient alternative species is crucial for sustainable fisheries. This study examines the impact of reduced pH and elevated temperature and their combined effects on the queen scallop Aequipecten opercularis in captivity. The results indicated that a low pH reduced its growth rates in both weight (0.03 ± 0.05 g/day) and length (0.06 ± 0.16 mm/day), as well as leading to decreases in meat yield (20.75 ± 2.75%) and the condition index (44.21 ± 7.19%). Conversely, elevated temperature resulted in an increased growth in length (0.07 ± 0.23 g/day), meat yield (21.57 ± 4.82%), and condition index (45.42 ± 7.35%). Combined stressors initially promoted growth but ultimately produced unsustainable outcomes, resulting in a reduced meat yield (18.28 ± 2.60%) and condition index (38.92 ± 8.23%), along with a peak mortality rate of 27%. These findings indicate that while A. opercularis can withstand individual stressors, exposure to simultaneous stressors may compromise its long-term viability in aquaculture systems.

The construction of a sheepmeat eating quality prediction model for Australian lamb

The current sheep Meat Standards Australia (MSA) model is a pathways system designed to improve the overall eating quality of Australian lamb, yet it is unable to predict individual consumer-based eating quality scores for specific cuts. This paper describes the methodology of using consumer sensory scores to create an objective composite eating quality prediction score linked to individual quality grades for different cuts. This methodology accounts for objective carcass measures that are being commercialised within the industry, such as intramuscular fat percentage and a measure of lean meat yield percentage. The model demonstrated that through utilising these carcass grading traits, an eating quality prediction can be made with an accuracy of 75 % and 72 % for the grill and roast cooking method respectively, however individual consumer variation remained substantial. The model will allow the supply chain to allocate cuts to different marketing strategies (branding) based on their eating quality performance whilst also reducing the chances of consumers being offered products that do not meet their expectations.

Comparison of Different Antibiotic Alternatives for Safe Broiler Production

The use of growth-promoting antibiotics in broiler feed, once widespread, is now recognized as risky due to antibiotic resistance and residue concerns in meat. To mitigate these risks, the goal of this study was to compare different alternative additives like organic acids, neem, enzymes, and probiotics for producing a safe broiler. A total of 360 Cobb-500-day-old broiler chicks were indiscriminately assigned into six treatment groups, i.e., Control (T1), Basal feed + Antibiotic (T2), Basal feed + Organic acid (T3), Basal feed + Enzyme (T4), Basal feed + Probiotic (T5), and Basal feed + Medicinal plant (T6) having four replications of 15 birds in each. During the experiment, significant differences (P &lt; 0.05) in body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) among the experimental groups were observed only in the 5th week. At the end of the study, the highest BW, BWG, and FCR were found in organic acid, followed by the enzyme, antibiotic, probiotic, neem, and control group. There were no significant differences (P &gt; 0.05) in BW, BWG, and FI among the dietary groups during the 1st, 2nd, 3rd, and 4th weeks. No significant differences (P &gt; 0.05) in meat yield (drumstick meat, thigh meat, wing weight, and breast meat), bone development, and dressing parameters were observed among the dietary groups. Supplementation of different additives significantly (P &lt; 0.05) affects cholesterol and glutamic oxaloacetic transaminase content, whereas HDL, LDL, triglyceride, GPT, and creatinine were not affected among the groups. The neem and organic acid groups had the lowest cholesterol and glutamic oxaloacetic transaminase values, respectively, compared to the others. It can be concluded that supplementing organic acid, probiotics, enzymes, and neem enhanced the growth performance, carcass quality, and blood biochemical profiles of the broilers, potentially serving as antibiotic alternatives. Mainly, the organic acid gives the best results among all the antibiotic alternatives.

The Feasibility of a Claw‐Only Fishery for the Red Rock Crab, Cancer productus

ABSTRACTThe red rock crab, Cancer productus, is primarily harvested by a recreational fishery, with a small commercial harvest in California. Although relatively large, meat yields are low because the legs are small, and meat is largely confined to the claws. We investigated the potential for a claw‐only harvest for this species. Although hand removal is used in the stone crab fishery, it caused &gt; 90% post‐harvest mortality in red rock crabs. Inducing autotomy by inserting a spike into the arthrodial membranes or by cutting into the autotomy plane resulted in a high post‐harvest survival. We recommend a minimum harvest size of 35 mm claw height to produce a claw size similar to medium‐sized stone crabs and standard‐sized brown and Jonah crabs and to ensure that severed claws are unlikely to have come from female crabs, which is important for regions that mandate a male‐only harvest.

Genomic insights into the specialisation and selection of the Jinding duck

The domestication of ducks represents a pivotal evolutionary shift from the unguided propagation of wild species to deliberate human-mediated selection, culminating in distinct behavioural, morphological, and physiological traits that differentiate domesticated ducks from their wild counterparts. This transition has yielded breeds with traits fine-tuned to specific economic roles, such as egg production, meat yield, or dual-purpose functionality. Duck domestication plays a significant role in poultry production globally, meeting the growing demand for eggs and meat in various regions. Here, we focus on the Jinding Duck (JDD), a breed renowned for its prolific egg-laying traits. Employing whole-genome resequencing data from 325 individuals across five Chinese indigenous duck breeds, we aimed to dissect the unique population structure and assess the genetic diversity within the JDD cohort. The findings reveal the distinct genetic heritage of JDD, diverged from other domesticated breeds, and show a relative paucity of genetic diversity. A salient discovery was a 200 kb genomic interval containing three genes (NCF2, SMG7, and ARPC5) with almost exclusive haplotypes, which were inherited from Anas platyrhynchos or Anas zonorhyncha, impacting the morphological attributes of JDD. The study highlights a c.28G>A non−synonymous mutation in the first exon of the LAMC1 gene, which is potentially influencing feather morphology in JDD. Our findings suggest that unique blue eggshell colouration in JDD is likely attributable to variations within the promoter element of the ABCG2 gene, distinguishing it from other breeds. Moreover, the MAP7 and FHL1 genes emerge as significant factors in the laying performance of JDD. These genetic insights are not only crucial for improving the JDD breed but also provide valuable information that could be applied to duck breeding programmes worldwide, helping enhance productivity and meet international demands for high-efficiency poultry breeds.

Impact of low crude protein diets containing animal byproducts on growth performance, nitrogen excretion, meat yield and quality in broiler chickens

This study examined the impact of a low crude protein (CP) diet incorporating meat and bone meal (MBM) as an alternative (AD) to standard diet, on broiler performance, nitrogen intake, excretion, and meat quality. A total of 846 male Ross 308 chicks were assigned to two diets in a randomized complete block design with 9 replicates of 47 birds/replicate. The diets were a plant-based control (20.4 and 19.5% CP) and an AD diet (-2.0% CP, +2.5% MBM) in the grower and finisher phases. Compared to the control, the AD diet reduced nitrogen intake (P = 0.01) and excretion (P &lt; 0.01) while improving nitrogen retention efficiency (P &lt; 0.001) without affecting body weight, feed conversion, or carcass yield. Breast yield was higher in the AD group (P &lt; 0.001). In the AD group, the ultimate pH of breast meat increased slightly (P = 0.07), cooking loss decreased (P = 0.002), sarcoplasmic protein solubility tended to increase (P = 0.09), while muscle protein emulsifying properties remained unchanged. Breast meat proximate composition was not affected by the AD diet. In conclusion, the AD diet can reduce nitrogen loss and emissions without negatively impacting broiler production, provided that amino acid requirements are met.

How do crate materials impact the winter transport of broilers?

Pre-slaughter transportation adversely impacts the welfare, meat yield, and quality of broilers, yet the effects of different crate types on broiler chickens during winter remain underexplored. The goal of this study was to investigate the effect of plastic and iron crates in transit on meat quality, carcass, and physiological traits of broiler chickens during winter. A total of 175, 35-day-old Ross 308 male broilers with an average body weight of about 1,708 ± 33.3 g (mean ± standard error of the mean) were picked after 4 hours of feed withdrawal before transport. The control group comprises birds in the farm (n = 15) without transportation at 173 cm2/kg density. The birds were transported into fixed iron (25 birds per crate) and plastic crates (15 birds per crate) with four replicates per crate type at the same 173 cm2/kg densities. The transportation distance was 20 km for 40 min at an average speed of 30-50 km/h early morning at 8:00 am under - 1 ℃ and 47% relative humidity. There was no difference (p>0.05) in carcass traits among the treatments. Concerning meat quality, broilers transported in both crate types exhibited lower (p<0.01) a* values compared to the control group. Additionally, the iron crate group demonstrated higher (p<0.05) b* values for the breast meat compared to the other groups. In terms of blood metabolites, the iron crate group had higher (p<0.05) cortisol, glucose, and lactate levels compared to the control group that did not transport. Broilers transported in the iron crates increase stress levels in terms of higher cortisol, glucose, and lactate contents in the blood plasma compared to untransported broilers during the winter. Therefore, employing plastic crates, which induce significantly reduced cortisol and numerically lower glucose levels compared to iron crates, appears more favorable for animal welfare by mitigating stress.

Effects of Black Soldier Fly Larvae Oil on Growth Performance, Blood Biochemical Parameters, Carcass Quality, and Metabolomics Profile of Breast Muscle of Thai Native Chickens.

This study aimed to evaluate the effects of the replacement of rice bran oil (RBO) with black soldier fly larvae oil (BSFLO) on growth performance, blood biochemicals, carcass quality, and metabolomics profile of breast muscle of Thai native chickens. A total of 192 1-day-old, mixed-sex, Pradu Hang Dam (Mor Kor 55) chickens were randomly allocated to one of three dietary groups. Each treatment had four replicates with 16 chicks per replicate (8 males and 8 females). Three dietary treatments were used: (T1) the control group, based on a corn-soybean meal with RBO, and two treatment groups that replaced 50% (T2) and 75% (T3) of RBO in the basal diet with BSFLO, respectively. Results showed that BSFLO inclusion at 50% and 75% did not adversely affect the productive performance of Thai native chickens (p > 0.05). Regarding blood profiles, on day 28, chickens fed 75% BSFLO exhibited significant increases in hemoglobin, hematocrit, and MCHC (mean corpuscular hemoglobin concentration) with lower eosinophil percentages compared to the control group (p < 0.05). Additionally, BSFLO supplementation raised glucose levels but decreased globulin and total protein levels (p < 0.05). On day 63, BSFLO inclusion primarily affected MCV (mean corpuscular volume), with higher values in the 50% BSFLO group (p < 0.05). It also increased globulin and HDL (high-density lipoprotein) levels while lowering AST (aspartate transaminase) concentrations (p < 0.05). For carcass and meat quality, BSFLO supplementation did not affect dressing percentage or edible meat yield (p > 0.05). However, it influenced meat pH and shear force (p < 0.05), with a higher pH at 24 h post-mortem in BSFLO-fed chickens. Metabolomics showed that arginine biosynthesis; phenylalanine, tyrosine, and tryptophan metabolism; alanine, aspartate, and glutamate metabolism; arginine and proline metabolism; and taurine and hypotaurine metabolism were the most differentially abundant. These findings suggest that BSFLO can be used for a partial replacement (50 to 75%) for RBO in Thai native chicken diets, potentially offering benefits for animal health and meat quality without compromising growth performance.

The efficacy of prebiotic supplementation in mitigating heat stress and improving the survival of antibiotic-free broilers’ production in hot climates

BackgroundBangladesh is a hot tropical country, and various antibiotics have been included in broiler feed for many years to manage, prevent, and treat illnesses and improve production performance, like many other developing countries. This study mainly evaluates the efficacy of prebiotic supplementation in mitigating heat stress and improving the survival of antibiotic-free broiler production in hot climates.Materials and methodsA cocktail of banana peel, papaya peel, and watermelon rind was used as a prebiotic. A total of 350 one-day-old chicks (Ross-308) were allotted into five treatment groups each with 7 replicates: T1 (prebiotics, 15 ml/L), T2 (commercial probiotics Lactolase P, 1 g/L), T3 (synbiotics, 7.5 ml/L prebiotics + 0.5 g/L probiotics), T4 (freshwater), and T5 (antibiotics, 1 g/L). Besides other treatments, the aqueous extracts of banana peels, papaya peels, and watermelon rinds were prepared as prebiotics, and these were provided to the experimental birds through drinking water from 5 to 32 days of age.ResultsThe findings revealed nonsignificant (P > 0.05) variations in water intake, feed intake, feed conversion ratio (FCR), dressing weight, dressing percentage, heart and gizzard weights, and thigh meat yield. Significant (p < 0.05) differences were observed in body weight, body weight gain, and breast meat yield. It was observed that birds consumed five times more water than feed when the environmental temperature was above 38 °C. Significant (p < 0.05) differences in the survival rates of birds were observed among treatment groups. The highest rate of survival was obtained in T1 (100%), followed by T2 (93.3%), and T3 (90%), and the lowest percentage was recorded in T4 (66.6%) and T5 (73.3%).ConclusionPrepared prebiotics could mitigate heat stress, promote growth rate under hot climates, and be used as substitutes for antibiotics to safely produce broilers in hot climates.

Are narwhals critical for the meat supply in East Greenland ?

In East Greenland, the recommendations for the closure of the narwhal (Monodon monoceros) hunt coincide with a pressing demand to continue hunting for meat to supply local communities. By analysing catch statistics and estimating average meat yields, the available meat from marine mammals, polar bears (Ursus maritimus), and muskox (Ovibos moschatus) in East Greenland can be assessed. On average, there was approximately 426 tonnes of meat available per year during this period. However, this quantity declined due to reduced catches of hooded seals (Cystophora cristata) and ringed seals (Phoca hispida) after 2007. This decline was somewhat offset by the inclusion of new species in the hunt, such as dolphins (Delphinidae), killer whales (Orcinus orca), and pilot whales (Globicephala melas). The average annual meat availability per inhabitant decreased from 150 kg before 2008 to 94 kg afterward. Narwhals consistently contributed approximately 5–6% of the total annual meat supply in Greenland over the observed period, which suggests that narwhal meat is not critical for the overall food supply. The inclusion of the need for meat in discussions surrounding sustainable harvest levels has been a point of controversy, particularly in cases where an urgent halt to hunting is needed.

A tactical carcass optimisation tool for assisting boning room managers to increase boning room profit

In collaboration with Australian lamb supply chains, an integer linear programming model was developed for use by processors to optimally allocate carcasses to different cutting plans for implementation in a boning room on a daily or lot basis. This tactical carcass optimisation tool (TCOT) addresses the daily challenge of developing operational plans to process carcasses into products whilst maximising profitability subject to constraints on carcass availability, variability of carcass weight and fatness, number of product orders, product size and retail prices. Predicted weights for all available products were derived from cut-weight prediction algorithms established from the combination of carcass weight and fatness ranges. Carcass fatness was expressed as lean meat yield percentage (LMY%) and measured using dual-energy X-ray absorptiometry (DXA) of hot carcasses immediately after slaughter. The TCOT utilises a group-based labour cost model which closely aligns with real-world supply chain practices. The function and application of the optimisation tool were tested in two contrasting case studies. The first case study demonstrated the ability of the optimiser to allocate carcasses to optimal cutting plans based on carcass weight and LMY%. The second case study examined the potential value of the tool for processors supplying lamb into the Australian domestic lamb market and subject to the constraints applied, demonstrated opportunities to increase profitability by at least 1 % compared to current best practice. This work provides a pathway whereby objective carcass measurement technology, combined with carcass sortation and optimisation algorithms, can be leveraged to improve profitability for lamb supply chains.

Impact of Forage Sources on Ruminal Bacteriome and Carcass Traits in Hanwoo Steers During the Late Fattening Stages.

This study examined the effects of different forage sources on the ruminal bacteriome, growth performance, and carcass characteristics of Hanwoo steers during the fattening stage. In Korea, where high-concentrate feeding is common, selecting suitable forage is crucial for sustainable beef production. Fifteen 23-month-old Hanwoo steers, weighing an average of 679.27 ± 43.60 kg, were fed the following five different forage sources: oat hay (OAT), rye silage (RYE), Italian ryegrass (IRS), barley forage (BAR), and rice straw silage (RSS), alongside 1.5 kg of dry matter concentrate daily for five months. Carcass traits were evaluated post-slaughter, and rumen fluid samples were analyzed using full-length 16S rRNA gene sequencing to determine the bacteriome composition. The forage source significantly affected the alpha-diversity indices and bacteriome biomarkers linked to the feed efficiency and ruminal fermentation. Differences in the backfat thickness and meat yield index were noted, with alpha-diversity indices correlating with carcass traits. The phylum Planctomycetota, especially the family Thermoguttaceae, was linked to nitrogen fixation in high-protein diets like IRS, while the genus Limimorpha emerged as a biomarker for the meat yield. These findings highlight the importance of forage selection during late fattening to optimize beef production, considering diet and bacteriome shifts.

Genome-wide association analysis identifies candidate genes for carcass yields in Peking ducks.

Poultry meat, particularly Peking ducks, holds a significant global market share, prized for their high meat yield and fat content. However, understanding of the molecular genetic mechanisms influencing carcass yield in ducks is limited. This research aims to use genome-wide association analysis to uncover single-nucleotide polymorphisms influencing carcass yield in Peking ducks, followed by identifying candidate genes linked to carcass traits. In this study, we analyzed seven traits of 643 Peking ducks at age 42 days and identified novel loci associated with these traits. A total of 35 significant loci were detected, with eight SNPs reaching genome-wide significance. KIF20B, AGBL5, SGSM1, MRO, PLAG1, XKR4, and TGS1 were considered as important candidate genes influencing carcass yield in ducks. This study adds to the list of genes affecting Peking duck body traits, aiding marker-assisted breeding and enhancing economic yield.

A study of solely used phytase or in combination with multi-carbohydrase on growth performance along with tibia mineralization, and carcass traits in broilers fed nutrient-deficient diets.

The objective of this study aimed to investigate the effectiveness of phytase alone and in combination with multi-carbohydrase in available phosphorus (AP) and energy-deficient diets on growth performance, nutrient digestibility, tibia traits, and carcass quality of broilers. A total of 288 1-d-old Ross 308 broiler chicks were randomly assigned to one of 6 dietary treatments in a completely randomized design, with each treatment having 6 replicates and 8 birds per cage. The treatments were as follows: 1) positive control with adequate nutrition (PC); 2) 0.20% AP-deficient diet without phytase (NC-1); 3) 0.25% AP-deficient diet without phytase (NC-2); 4) NC-1 diet plus 500 FTU/kg phytase (NCP-1); 5) NC-2 diet plus 750 FTU/kg phytase (NCP-2); and 6) NC-2 with 100 kcal/kg ME deficient diet plus 1,000 FTU/kg phytase and multi-carbohydrase: 2,200 U/kg galactomannanase, 30,000 U/kg xylanase, 22,000 U/kg β-glucanase, and 700 U/kg α-galactosidase (NCPM). Broilers in the PC group and those fed enzyme-supplemented diets exhibited greater (P < 0.05) growth performance in terms of body weight, average daily gain, and feed conversion ratio, along with enhanced tibia mineralization through the ash, calcium (Ca), phosphorus (P) composition, and tibia breaking strength compared to NC diets throughout the study. Among the treatments, broilers assigned to the NCPM group showed greater (P < 0.05) levels of energy and P digestibility on days 21 and 35. Concerning carcass characteristics, the leg meat yield was greater (P < 0.05) in broilers fed the NCP-2 diet compared to all other treatments on days 21 and 35. Supplementation of phytase at doses of 500 FTU/kg and 750 FTU/kg effectively recovers AP deficiencies of 0.20% and 0.25%, respectively, in broiler diets without compromising the growth performance of broilers. Additionally, combining multi-carbohydrase and phytase led to AP and energy loss recovery, which improved tibia mineralization and nutrient digestibility through their synergistic interaction.

Can Productive Aptitude and Age Affect Circulating Serotonin, Total Thyroid Hormones, and Cortisol Patterns in Cows?

Cattle productivity, whether in terms of meat yield or milk production, is intricately regulated by a multitude of factors. Among them, hormone concentrations play a significant role, reflecting the complex interplay between endocrine regulation and physiological processes that ultimately determine the efficiency and yield of production. High concentrations of 5-hydroxytriptamine (5-HT) are associated with a reduced metabolic load at the onset of lactation and a lower milk yield. Thyroid hormones (THs) and cortisol also affect several metabolic pathways, including carbohydrate, protein, and lipid metabolism. The aim of this study was to assess if milk or meat aptitudes and age influence circulating 5-HT, THs, and cortisol concentrations, investigating the possible interactions among these parameters. The research was performed on 46 healthy cows of three different breeds. Enzyme-linked immunosorbent assay (ELISA) methods were used to quantify circulating 5-HT and cortisol concentrations, and an immunochemiluminescent analyzer was used for THs. For parameters exhibiting non-normal distributions, an ANCOVA model using age, aptitude, and their interaction as fixed factors was applied. Significant lower T3 concentrations were recorded in dairy cows than in meat cows. Moreover, T4 significantly decreased with advancing age both in cows aimed at milk and meat production. Lastly, T4 was positively correlated with T3 and 5-HT in meat production-oriented cows.

Effect of 25-hydroxycholecalciferol and high phytase doses on performance, vitamin D status, bone mineralization, and mechanistic target of rapamycin kinase gene expression of broilers

The use of exogenous phytase and vitamin D3 metabolites such as 25-hydroxycholecalciferol (25-OH-D3) for poultry is well consolidated, but the potential for additive effects when supplementing both requires further investigation. This study investigated possible interactions between supplementation of 25-OH-D3 and high doses of phytase for broilers fed Ca− and P-deficient diets. A total of 1 200 one-d-old male broiler chicks were randomly allocated from one of four dietary treatments in a 2 × 2 factorial arrangement: 600 or 2 000 phytase units (FYT)/kg and with or without the inclusion of 25-OH-D3 at 69 µg/kg, with 12 replicates of 25 broilers each. Two feeding phases were stablished (1-to-21 and 22-to-42 d) and all diets contained commercial levels of vitamin D3 (100 µg/kg) with total Ca and available P respectively set to 0.6 and 0.3%. Supplementation with 25-OH-D3 increased body weight gain (BWG) and reduced feed conversion ratio (FCR) from 1 to 21 d (P < 0.05), as well as increased BWG from 1 to 42 d (P < 0.05). Serum 25-OH-D3 levels at 21 and 42 d were increased with 25-OH-D3 (P < 0.001). Phytase did not affect growth performance from 1 to 21 d, but a higher dose (2 000 FYT/kg) reduced feed intake and FCR from 22 to 42 d compared to 600 FYT/kg, also reducing FCR in the total period (P < 0.05). Expression of the mechanistic target of rapamycin mRNA in breast muscle assessed at 42 d was enhanced with 2 000 FYT/kg (P < 0.001). Bone weight, bone contents of ash, Ca, and P, and bone breaking strength of tibia bone measured at 42 d were not affected by any dietary treatment. Although both additives are known to improve dietary Ca and P utilization, there were no detected additive or synergic effects. The results suggested that the inclusion of 25-OH-D3 and phytase combined with regular vitamin D3 levels can help minimize losses of performance and bone mineralization of broilers fed Ca- and P-deficient diets. Furthermore, vitamin D status is refined with dietary 25-OH-D3 and potential improvements on breast meat yield can be obtained with a high phytase dose of 2 000 FYT/kg.