Effects of brewery by-products based silage on productive performance of crossbred dairy cows.

The present study aimed to evaluate the effect of an increasing levels of brewery by-products based silage on productive performances of 3/4 Friesian x Boran mid-lactating cows. Experimental cows had similar in initial milk yield (11.7 ± 1.0), average days in milk (81.7 ± 6.1) and live weight (LW, 430.7 ± 40.3 kg) but different in parities (2-5).The dietary treatments were arranged randomly in 4 × 4 Latin Square Design that included ad libitum natural pasture hay feeding for all treatments as a roughage source plus a commercial dairy concentrate mix supplemented at 0.5 kg DM (dry matter)/liter of milk produced/day for cows in the control group (T1) and 0.3, 0.5 and 0.7 kg DM of brewery by-products based silage per liter of milk yield/cow/day for cows in T2, T3 and T4 groups, respectively. The study revealed that the daily milk yield of experimental cows was influenced by dietary treatments with relatively higher daily milk yield being recorded (P < 0.05) for cows in the T4 (13.9 l) followed by T3 (13.8 l). Milk composition of cows remained unchanged (P > 0.05) except for fat percentage of the milk that showed a declining trend (P < 0.05) with incremental inclusion levels of brewery by-products based silages. The highest net income (NI, 437.9 Eth. Birr) and marginal rate of return (MRR, 800.7%) was obtained for cows receiving brewery by-products based silage at the rate of 0.7 kg/liter of milk yield as compared to cows in the other treatment groups. Further study is required on the long term effect of brewery by-products based silage supplementation on productive, reproductive performance, and milk microbial qualities.

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.

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.

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.

Performances, carcass characteristics, and economic benefit of yearling Hararghe highland rams fed diet containing concentrate mixtures and sugarcane bagasse or rice husk treated with Trichoderma viride and effective microorganisms.

The productivity of small ruminants in Ethiopia is low due to a shortage of feed supply throughout the year, both in terms of quality and quantity. This problem leads to the utilization of locally available lignocellulose by-products, which encompass high cellulose, hemicellulose, and lignin. It is known that the nutritive value of these lignocellulose by-products can be improved through biological, chemical, or a combination of both treatments This study was aimed at evaluating body weight change, carcass characteristics, and economic efficiency of rams fed a total mixed diet containing biologically treated rice husk (RH) or sugarcane bagasse (SCB). Thirty-six sheep, weighing an average initial body weight of 18 ± 1.8 kg were used. Two feeds (SCB and RH) and three biological treatments (Control, Trichoderma viride [Tv], and effective microbes [EM]) were used with a randomized complete block design (RCBD) in 2 × 3 factorial arrangements. Ram fed on RH containing diets had higher dry matter intake (DMI) (g/h/day), DMI (% of BW), DMI (g/kg BW0.75), average daily gain (ADG) (106 vs. 53 g/day), and feed conversion efficiency (FCE) (0.107 vs. 0.076) than SCB containing diets. Ram fed diets containing biologically treated roughages had significantly higher (p < .05) DMI (g/h/day), DMI (% of BW), DMI (g/kg BW0.75), ADG, and FCE. However, no significant differences were observed between sheep fed diets containing EM and Tv in DMI (g/h/day), DMI (% of BW), DMI (g/kg BW0.75), ADG, and FCE. This study also revealed that significantly (p < .05) higher carcass weight, dressing percentage (DP), rib eye muscle area, total non-carcass fat, and total edible offal components had been recorded for rams fed diets containing RH as roughage source related to rams fed diets containing SCB. While other parameters were unaffected by treatments, sheep fed diets containing biologically treated feed had a higher hot carcass weight plus DP. However, no significant (p > .05) difference was found between diets based on biologically treated roughage. Profitability analysis indicated that sheep fattening on a diet containing RH and by-products treated with Tv and EM showed greater profitability than untreated SCB. The authors had concluded that fattening sheep on diets containing RH results in higher feed intake, better body weight gain, more carcasses and higher profits, but optimum inclusion levels need further research, for either treated or untreated SCB.

Genetic Parameter Estimates of Growth Curve and Feed Efficiency Traits in Japanese Quail.

This study aimed to estimate heritabilities for weekly body weight traits, the Gompertz growth curve parameters, and feed efficiency characteristics, as well as genetic correlations among characteristics. A total of 700 Japanese quails with pedigree records were used in this study. Body weight and feed consumption were measured individually on a weekly basis. Using weekly body weight data, the growth model parameters were estimated for each bird using the Gompertz nonlinear regression model. Multi-trait variance-covariance matrices were obtained with Bayesian inference using the Gibbs sampler. While estimates of high heritability (0.59 to 0.61) were found for weekly body weight traits, estimates of moderate heritability (0.23 to 0.37) were determined for feed intake and feed conversion efficiency traits. The estimated heritabilities for the parameters of the Gompertz model and inflection point coordinates were moderate (0.37 to 0.47). While genetic correlations between feed intake and body weight characteristics were positive and moderate (0.28 to 0.49), the genetic correlations between feed conversion efficiency and body weight traits were positive and strong (0.52 to 0.83). It has been concluded that the moderate negative genetic relationship between feed conversion efficiency and body weight may constrain selection studies. Due to the weak genetic correlation between the asymptotic body weight parameter of the Gompertz model and the feed conversion efficiency, it is thought that the total genetic gain will be greater if the mature weight parameter is also used as a selection criterion in genetic improvement studies.

Combined transcriptome and metabolome analysis reveal key regulatory genes and pathways of feed conversion efficiency of oriental river prawn Macrobrachium nipponense.

BACKGROUND: Oriental river prawn Macrobrachium nipponense is an economically important aquaculture species in China, Japan, and Vietnam. In commercial prawn farming, feed cost constitutes about 50 to 65% of the actual variable cost. Improving feed conversion efficiency in prawn culture will not only increase economic benefit, but also save food and protect the environment. The common indicators used for feed conversion efficiency include feed conversion ratio (FCR), feed efficiency ratio (FER), and residual feed intake (RFI). Among these, RFI is much more suitable than FCR and FER during the genetic improvement of feed conversion efficiency for aquaculture species. RESULTS: In this study, the transcriptome and metabolome of hepatopancreas and muscle of M. nipponense from high RFI low RFI groups, which identified after culture for 75 days, were characterized using combined transcriptomic and metabolomic analysis. A total of 4540 differentially expressed genes (DEGs) in hepatopancreas, and 3894 DEGs in muscle were identified, respectively. The DEGs in hepatopancreas were mainly enriched in KEGG pathways including the metabolism of xenobiotics by cytochrome P450 (down-regulated), fat digestion and absorption (down-regulated) and aminoacyl-tRNA biosynthesis (up-regulated), etc. The DEGs in muscle were mainly enriched in KEGG pathways including the protein digestion and absorption (down-regulated), glycolysis/gluconeogenesis (down-regulated), and glutathione metabolism (up-regulated), etc. At the transcriptome level, the RFI of M. nipponense was mainly controlled in biological pathways such as the high immune expression and the reduction of nutrients absorption capacity. A total of 445 and 247 differently expressed metabolites (DEMs) were identified in the hepatopancreas and muscle, respectively. At the metabolome level, the RFI of M. nipponense was affected considerably by amino acid and lipid metabolism. CONCLUSIONS: M. nipponense from higher and lower RFI groups have various physiological and metabolic capability processes. The down-regulated genes, such as carboxypeptidase A1, 6-phosphofructokinase, long-chain-acyl-CoA dehydrogenase, et. al., in digestion and absorption of nutrients, and the up-regulated metabolites, such as aspirin, lysine, et. al., in response to immunity could be potential candidate factors contributed to RFI variation for M. nipponense. Overall, these results would provide new insights into the molecular mechanism of feed conversion efficiency and assist in selective breeding to improve feed conversion efficiency in M. nipponense.

The Effect of Direct-Fed Lactobacillus Species on Milk Production and Methane Emissions of Dairy Cows.

Using direct-fed microbials to mitigate enteric methane emissions could be sustainable and acceptable to both consumers and producers. Forty lactating, multiparous, Holstein-Friesian cows were randomly allocated one of two treatments: (1) a base of ad libitum vetch (Vicia sativa) hay and 7.0 kg DM/d of a grain mix, or (2) the basal diet plus 10 mL of MYLO® (Terragen Biotech Pty Ltd., Coolum Beach, Queensland, Australia) delivering 4.17 × 108 cfu of Lactobacillus per mL. Neither feed intake (25.4 kg/d vs. 24.8 kg/d) nor milk yield (29.9 vs. 30.3 kg/d) were affected by treatment. Feed conversion efficiency was not affected by treatment when expressed on an energy-corrected milk basis (1.15 vs. 1.18 kg/kg DMI). Neither methane yield (31.6 vs. 31.1 g/kg DMI) nor methane intensity (27.1 vs. 25.2 g/kg energy corrected milk) were affected by treatments. While these results are contrary to our expectations and not significant, all were numerically in a favorable direction. Given there are reports that diet and dose rate may impact the size of any effect, we recommend a dose-response study be undertaken using a basal diet that is commonly used in pasture-based dairy systems.

Gas to protein: Microbial single cell protein is an alternative to fishmeal in aquaculture.

Methanotrophic bacteria represent an appealing opportunity to convert methane, a potent greenhouse gas, into a highly nutritious animal feed ingredient, single-cell protein (SCP). SCP has a comparable or superior nutritional profile that to most conventional protein sources and can be produced within a lower environmental footprint. The present study investigated the effect of replacing fishmeal (FM) with methanotrophic SCP in diets for barramundi (Lates calcarifer), a carnivorous fish with a high demand for dietary protein and energy. Dietary inclusion levels of 0 %, 10 %, 20 % and 30 % SCP (representing 0, 25, 50 and 75 % FM replacement) were tested, with and without additives. Triplicate groups of juvenile barramundi were fed the diets over 31 days. The inclusion of SCP significantly improved weight gain and feed conversion efficiency (FCE). Dietary SCP inclusion supported good gut health, with decreasing trends of hepatosomatic index, improved plasma biochemistry, and no adverse histopathological changes. Barramundi fed the SCP diets showed an intact intestinal barrier and a significant improvement in villi and lamina propria area when fed the additive supplemented SCP diets. This study demonstrates that this SCP is highly palatable to barramundi (even without dietary additives) and can replace up to 75 % FM with significant improvements in growth and FCE.

Intake, digestibility, growth performance and blood profile of rams fed sugarcane bagasse or rice husk treated with Trichoderma viride and effective microorganisms.

Sugarcane bagasse and rice husk are lignocellulose rich agricultural by-products designated as an alternative feed for ruminant. However, their nutritive value is relatively low due to low digestibility, high fiber content, low protein content and low palatability. Therefore, the nutritional value of these by-products can be improved with biological treatments. The objective of this study to evaluate the feed intake, digestibility, growth performance and blood profile of Hararghe highland sheep fed biologically treated rice husk (RH) or sugarcane bagasse (SCB) in concentrate mixtures. Thirty six rams with an average age of 10 months and an average initial weight of 18 ± 1.8kg were assigned in randomized complete block design (RCBD) in 2 × 3 factorial arrangements, with two feeds (SCB and RH) and three treatment groups (Control, Trichoderma viride and effective microorganism (EM)). 5% EM1 was used to prepare the activated EM solution and 5% Trichoderma viride (Tv) solution was used to prepare inaculant. Sheep were fed ad libitum for 90 days at 20% refusal rate followed by10 days of digestibility trial. Nutrient intake and digestibility of sheep were significantly (p < 0.05) affected by the interaction. Sheep fed either treated or untreated rice husk based diets had significantly higher dry matter (DM g/d), organic matter (OM g/d), crude protein (CP g/d) and metabolizable energy (ME MJ/d) intake than a diet based on untreated sugarcane bagasse or treated with Trichoderma viride. Sheep fed diets containing either treated or untreated rice husks had a higher average daily weight gain (ADG) and feed conversion efficiency than sugarcane bagasse containing diets. Sheep fed diets containing biologically treated roughages had significantly higher (p < 0.05) average daily weight gain and feed conversion efficiency. Conversely, no significant differences were observed between rams fed diets containing EM and Trichoderma viride (Tv) treated rice husk or sugarcane bagasse in average daily weight gain (ADG) and feed conversion efficiency (FCE). Values of some blood hematology (red blood cell, haemoglobin and packed cell volume) and total protein, urea, glucose and cholesterol of serum metabolites were significantly (p < 0.05) higher for rams fed diet containing rice husk. In conclusion, the results show that the biological treatment of feed with the effective microorganism or Trichoderma viride improved nutrient utilization and average daily gain in the sheep fattening diet.

Genomic polymorphisms at the crhr2 locus improve feed conversion efficiency through alleviation of hypothalamus-pituitary-interrenal axis activity in gibel carp (Carassius gibelio).

Improvement in fish feed conversion efficiency (FCE) is beneficial for sustaining global food fish supplies. Here, we show that a set of polymorphisms at locus of the corticotropin releasing hormone receptor 2 (crhr2), which is involved in hypothalamus-pituitary-interrenal (HPI) axis signaling, is associated with improved FCE in farmed allogynogenetic gibel carp strain CAS III compared with that in the wild gibel carp strain Dongting (DT). This set of polymorphisms downregulates the expression levels of crhr2 mRNA in the brain and pituitary tissues in gibel carp strain CAS III compared with those in strain DT. Furthermore, compromised HPI axis signaling is observed in gibel carp strain CAS III, such as decreased α-melanocyte stimulating hormone protein levels, plasma cortisol content, and stress responses. Moreover, enhanced activation of protein kinase B/mammalian target of rapamycin complex 1 signaling observed in the muscle tissue of strain CAS III in comparison to that in strain DT indicated elevated anabolic metabolism in strain CAS III. Thus, these studies demonstrate that the genetic markers associated with compromised HPI axis signaling, such as crhr2, are potentially useful for genetic selection toward improvement in farmed fish growth and FCE, which would reduce fishmeal consumption and thereby indirectly facilitate sustainable fisheries.

A High-Density Genetic Linkage Map and Fine Mapping of QTL For Feed Conversion Efficiency in Common Carp (Cyprinus carpio).

Feed conversion efficiency (FCE) is an economically crucial trait in fish, however, little progress has been made in genetics and genomics for this trait because phenotypes of the trait are difficult to measure. In this study, we constructed a high-density and high-resolution genetic linkage map with 28,416 SNP markers for common carp (Cyprinus carpio) based on high throughput genotyping with the carp 250K single nucleotide polymorphism (SNP) array in a full-sib F1 family of mirror carp (Cyprinus carpio) consisting of 141 progenies. The linkage map contained 11,983 distinct loci and spanned 3,590.09 cM with an average locus interval of 0.33 cM. A total of 17 QTL for the FCE trait were detected on four LGs (LG9, LG20, LG28, and LG32), explaining 8.9-15.9% of the phenotypic variations. One major cluster containing eight QTL (qFCE1-28, qFCE2-28, qFCE3-28, qFCE4-28, qFCE5-28, qFCE6-28, qFCE7-28, and qFCE8-28) was detected on LG28. Two clusters consisting of four QTL (qFCE1-32, qFCE2-32, qFCE3-32, and qFCE4-32) and three QTL (qFCE1-20, qFCE2-20, and qFCE3-20) were detected on LG32 and LG20, respectively. Nine candidate genes (ACACA, SCAF4, SLC2A5, TNMD, PCDH1, FOXO, AGO1, FFAR3, and ARID1A) underlying the feed efficiency trait were also identified, the biological functions of which may be involved in lipid metabolism, carbohydrate metabolism, energy deposition, fat accumulation, digestion, growth regulation, and cell proliferation and differentiation according to GO (Gene Ontology). As an important tool, high-density and high-resolution genetic linkage maps play a crucial role in the QTL fine mapping of economically important traits. Our novel findings provided new insights that elucidate the genetic basis and molecular mechanism of feed efficiency and the subsequent marker-assisted selection breeding in common carp.

Analysis of Life Cycle Environmental Impacts of Using Enogen Corn in Beef Cattle Rations.

Agricultural production systems have been identified as significant sources of anthropogenic impacts across several environmental key performance indicators (KPIs). Livestock husbandry is growing in global importance as the demand for high-quality protein continues to increase. It is therefore imperative to have sustainable intensification technologies, and we describe one such technology. The purpose of this study was to evaluate the performance of Enogen® corn grain compared to conventional feed corn when used as an ingredient in backgrounding and feed yard beef rations using life cycle assessment. The project was conducted in compliance with ISO standards, including a third-party panel review. A series of scenarios were analyzed to evaluate the impacts of boundaries and functional units on the outcomes. The use of Enogen corn as a feed component in beef production showed a quantifiable benefit in terms of the sustainability metrics of primary interest in this study. The gate-to-gate improvements at the feed yard and backgrounding based on full field trial datasets from field trials conducted at Kansas State University and at the University of Nebraska, Lincoln showed 3.4 and 5.8 percent reductions in Global Warming Potential, respectively. It is particularly noteworthy that the improvement in feed conversion ratio at the feed yard results in approximately 6 percent improvement in the four key environmental performance metrics of beef production, which demonstrates potential for the sector to meet its sustainability targets.

Effects of dietary energy and protein levels on nutrient intake, digestibility, and body weight change in Hararghe highland and Afar sheep breeds of Ethiopia.

OBJECTIVES: The experiment was conducted to determine the effect of dietary energy and protein level growth performances of selected indigenous Ethiopian sheep breeds. MATERIALS AND METHODS: Fifty intact ram lambs, 25 from each breed with 12 months of age and a mean initial body weight (IBW) of 19.31 ± 1.7 kg, were employed for this experiment. Animals were distributed randomly into five dietary treatments, i.e., minimum Energy and Protein (mEmP), medium energy and protein (MEMP), medium Energy and high Protein (MEHP), high energy and medium protein (HEMP), and high Energy and high Protein (HEHP) diets in randomized complete block design with 2 * 5 factorial arrangements. The minimum, medium, and high energy diets were 2.388, 2.866, and 3.344 Mcal/kg dry matter (DM) with the corresponding 10%, 16%, and 20% crude protein (CP) diets, respectively. The diets were formulated in a total mixed ration from wheat bran (WB), maize grain, peanut cake, and pasture hay feed ingredients. Diet offer was at the rate of 3% of lambs' live weight and revised biweekly as per the attained body weight changes. Digestibility trial was conducted for 7 days of actual fecal data collection, followed by 90 days of feeding trial. RESULTS: The animals fed on the MEHP diet had a maximum DM and nutrient intakes (CP and organic matter) and the best final body weight (FBW), total gain, gain rate, average daily gains, and feed conversion efficiency (31.3, 12.9 kg, 41.2%, 143.3 gm, and 23.13, respectively), followed by HEMP, HEHP, MEMP, and mEmP diets. Digestibility of DM and nutrients linearly followed similar trends (p < 0.01). Hararghe sheep was heavier (p < 0.01) by 4.3 and 3.1 kg in its FBW and total gain and more efficient in nutrients utilization (22.57 vs. 18.18) as compared to Afar sheep (AS). CONCLUSION: It is concluded that MEHP and MEMP are superior and optimum diets for sheep breeds, and Hararghe sheep is carried out better than AS in most growth performance parameters.

Plasma proteins δ15N vs plasma urea as candidate biomarkers of between-animal variations of feed efficiency in beef cattle: Phenotypic and genetic evaluation.

Identifying animals that are superior in terms of feed efficiency may improve the profitability and sustainability of the beef cattle sector. However, measuring feed efficiency is costly and time-consuming. Biomarkers should thus be explored and validated to predict between-animal variation of feed efficiency for both genetic selection and precision feeding. In this work, we aimed to assess and validate two previously identified biomarkers of nitrogen (N) use efficiency in ruminants, plasma urea concentrations and the 15N natural abundance in plasma proteins (plasma δ15N), to predict the between-animal variation in feed efficiency when animals were fed two contrasted diets (high-starch vs high-fibre diets). We used an experimental network design with a total of 588 young bulls tested for feed efficiency through two different traits (feed conversion efficiency [FCE] and residual feed intake [RFI]) during at least 6 months in 12 cohorts (farm × period combination). Animals reared in the same cohort, receiving the same diet and housed in the same pen, were considered as a contemporary group (CG). To analyse between-animal variations and explore relationships between biomarkers and feed efficiency, two statistical approaches, based either on mixed-effect models or regressions from residuals, were conducted to remove the between-CG variability. Between-animal variation of plasma δ15N was significantly correlated with feed efficiency measured through the two criteria traits and regardless of the statistical approach. Conversely, plasma urea was not correlated to FCE and showed only a weak, although significant, correlation with RFI. The response of plasma δ15N to FCE variations was higher when animals were fed a high-starch compared to a high-fibre diet. In addition, we identified two dietary factors, the metabolisable protein to net energy ratio and the rumen protein balance that influenced the relation between plasma δ15N and FCE variations. Concerning the genetic evaluation, and despite the moderate heritability of the two biomarkers (0.28), the size of our experimental setup was insufficient to detect significant genetic correlations between feed efficiency and the biomarkers. However, we validated the potential of plasma δ15N to phenotypically discriminate two animals reared in identical conditions in terms of feed efficiency as long as they differ by at least 0.049 g/g for FCE and 1.67 kg/d for RFI. Altogether, the study showed phenotypic, but non-genetic, relationships between plasma proteins δ15N and feed efficiency that varied according to the efficiency index and the diet utilised.

The physiological role of guanidinoacetic acid and its relationship with arginine in broiler chickens.

The role of guanidinoacetic acid (GAA) and its relationship with arginine was reviewed in order to define a replacement ratio between GAA and arginine for broiler diet formulation, the ratio being of how much arginine could be spared, or replaced by GAA. Guanidionoacetic acid, the precursor of creatine, can be synthesized de novo from the amino acids arginine and glycine, whereby 1 mol of arginine creates 1 mol of GAA; that is a weight:weight (w:w) ratio of 1.49:1 (arginine:GAA). Guanidinoacetic acid exerts a growth effect through its primary physiological fate to form creatine, and additionally spares dietary arginine from GAA synthesis; so that it contributes to protein accretion and other functions. Creatine is critical in energy metabolism as a carrier and reservoir of phosphate for adenosine triphosphate (ATP) formation. Arginine deficiency causes reduced growth and can lead to disrupted levels of blood and muscle energy metabolites (phosphocreatine and creatine). Supplementing GAA into the diet restores these metabolites. At severe arginine deficiency, GAA addition cannot fully compensate the arginine deficit, as measured by growth performance. As arginine becomes nearer to sufficiency, the effect of GAA becomes more pronounced. When using growth rate or FCR as an indicator in broilers, a ratio in the range of 0.77 to 1.3:1 (w:w arginine:GAA) was seen, with one study noting a ratio of 2:1 when using FCR as an indicator. Higher ratios of up to 2.7:1 are achieved when using muscle creatine and phosphocreatine measurements. A recommendation of 1:1 (w:w) is proposed, which takes a conservative approach. Large scale studies with practical diets would be helpful to confirm that a ratio of 1:1 (w:w) or higher may be used in the field for broilers.

Rearing Tenebrio molitor and Alphitobius diaperinus Larvae on Seed Cleaning Process Byproducts.

The exploitation of agricultural byproducts and organic side-streams as insect feeding substrates is advantageous for insect farming both from an economic and a sustainability perspective. In this context, in the present study we evaluated the suitability of ten byproducts of the cereal and legume seed cleaning process for the rearing of larvae of the yellow mealworm, Tenebrio molitor, and the lesser mealworm, Alphitobius diaperinus. Byproducts were offered singly to 20 T. molitor and 50 A. diaperinus larvae with provision of carrots as moisture source. After four weeks of undisturbed development, larval weight and survival was evaluated biweekly until pupation. Feed utilization and economic feasibility parameters were determined for each byproduct at the end of the bioassays. Our results show the suitability of several of the byproducts tested for the rearing of T. molitor and A. diaperinus larvae. The best results though among the byproducts tested in terms of larval growth and survival, development time and feed utilization were obtained with larvae fed with lupin and triticale byproducts, which efficiently supported complete larval development. The results of our study aim to boost the integration of circular economy strategies with insect farming practices.

The effect of plant bioactive compounds on lamb performance, intake, gastrointestinal parasite burdens, and lipid peroxidation in muscle.

Plant extracts have been widely used in animal production systems due to the benefits promoted by their bioactive components, mainly through their antioxidant effects and positive effects on animal growth, health, and meat quality. We determined whether bioactive compounds (BC) from grape (Vitis vinifera), olive (Olea europaea), and pomegranate (Punica granatum) have beneficial effects on lamb growth while controlling gastrointestinal parasitism and reducing skeletal lipid peroxidation in muscle. Fourteen lambs (4 to 5 mo of age) were housed in individual pens and assigned to two treatment groups (seven animals/group), where they received: 1) a basal diet of beet pulp:soybean meal (90:10) (CONTROL) and 2) the same diet, but containing 0.3% of BC extracted from grape, olive, and pomegranate (BNP). After 21 d of consuming their respective rations (period 1), all lambs were dosed with 10,000 L3 stage larvae of Haemonchus contortus. Intake, production, and physiological parameters were determined before infection (period 1), after oral dosage with L3 (period 2), and during early (period 3) and later (period 4) developmental stages of infection. Groups of animals did not differ in their ration intake or average daily gain, either before or after the infection, or in their parasitic burdens estimated through fecal egg counts (P > 0.05). Lambs under BNP showed greater feed efficiency before infection (P < 0.001), but the pattern reversed after infection. In addition, the inclusion of plant bioactives to the diet did not have an effect (P > 0.05) on blood or lipid peroxidation in muscle or on hemogram, serum concentration of haptoglobin, and immunoglobulin E. These results could be explained by low dietary doses and constrained absorption or ruminal inactivation of these compounds. Changes in feed efficiencies suggest a negative interaction between BC in the diet and parasitism, which warrants further research.

Feeding unsaleable carrots to lambs increased performance and carcass characteristics while maintaining meat quality.

This study investigated the effect of feeding unsaleable carrots to lambs within a total-mixed ration (TMR) on performance, carcass characteristics, meat quality and sensory parameters. Thirty-six Australian Merino wether lambs were fed a control (barley-based) or carrot-based TMR for 11-weeks. Carrot-fed lambs had 2.7% higher cold dressing percentage (P = 0.03) while consuming less than control lambs. Subcutaneous fat of carrot-fed lambs contained less branch-chained, and more cis- and trans-monounsaturated fatty acids (FA; P ≤ 0.01) compared to control-fed lambs, which tended (P = 0.08) to have higher concentrations of polyunsaturated FA, despite the Longissimus lumborum (LL) muscle being unchanged by diet. Under retail display conditions, L* and hue values were lower (P ≤ 0.04) for 5 d aged LL samples from carrot-fed lambs. No differences were observed in other meat quality and sensory parameters between diets. Therefore, feeding unsaleable carrots at 45% DM in a TMR can improve lamb performance and carcass characteristics, while maintaining meat quality and FA composition.

Sustainability of Four Dairy Farming Scenarios in an Alpine Environment: The Case Study of Toma di Lanzo Cheese.

The dairy sector accounts for a large share of all European agricultural production, at the same time however, it is one of the most ascribed sector contributors to the environmental impact of agriculture, particularly for greenhouse gas emissions. Simultaneously, it is a strategic sector for the economy but generates increasing debate in the community regarding the social aspects mainly related to the use of resources and the food-feed competition of livestock involving the reduction of human-edible crops. In this general framework, this study aims to compare four different dairy farming scenarios characterized by different use of environmental resources in the Alpine area, considering as a case study the production of the Toma di Lanzo cheese (a traditional cheese produced in the mountainous regions of Piedmont-Northwest Italy). The study envisaged the integrated use of three methodologies: Life Cycle Assessment, Life Cycle Costing and the assessment of human-edible feed conversion efficiency to jointly analyze environmental, economic and social aspects. The main results of this research highlighted how the utilization of local breeds, which maximize the efficiency in the use of territory resources, such as grasslands in a mountain environment, allowed dairy production to reduce emissions, when compared to the high-input traditional breeding systems. Although the mountain livestock systems have several critical issues mainly linked to social factors such as low generational turnover, work schedules, modest life quality of families, it is however possible to earn more income than in lowland scenarios. At the same time, this production system allows the Toma di Lanzo cheese-making heritage to be preserved. This mountain pasture cheese, to which superior organoleptic and nutritional characteristics are attributable, when compared to cheeses from the valley floor, incorporates traditional values, a link to the territory and the transmission of knowledge. With reference to food-feed competition in livestock involving the reduction of the use of human-edible crops and feedstuffs in animal diets, we found that grazing and grass-based feeding systems were one of the most sustainable ways to produce milk.