Low Crude Protein Research Articles

Nutritional composition of New Zealand native shrubs edible portions with fodder potential for ruminants

ABSTRACT In New Zealand, willow and poplar are used on hill farms for erosion control and to supplement pasture during low pasture periods. Some native shrubs are browsed by wild herbivores but remain unexplored for farmed ruminants. We evaluated the seasonal nutritional composition of five native New Zealand shrubs (Karamū, Pāpāuma, Karo, Whauwhaupaku, and Houhere) and compared them with willow (Kinuyanagi). Leaf and edible stem were analysed for nutritional composition and in vitro digestibility following AOAC procedures. Results showed that except Houhere, all other native shrubs leaves had lower crude protein (CP) (11 MJ/ kg DM) than Kinuyanagi. Kinuyanagi leaves were comparable to Houhere in ME and CP in spring but had lower CP in summer. Stem nutritional composition was similar across all shrubs. Acid and neutral detergent fibres in edible portions were comparable to those in common pastures, fodder crops, and forages in New Zealand. The findings suggest native shrubs could supplement low ME in summer pastures or winter herbage scarcity, but further research is needed on animal preference and intake.

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 < 0.01) while improving nitrogen retention efficiency (P < 0.001) without affecting body weight, feed conversion, or carcass yield. Breast yield was higher in the AD group (P < 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.

Effect of Dietary Crude Protein Reduction Levels on Performance, Nutrient Digestibility, Nitrogen Utilization, Blood Parameters, Meat Quality, and Welfare Index of Broilers in Welfare-Friendly Environments.

We investigated the effects of feeding different levels of crude protein (CP) on broiler performance, blood characteristics, meat quality, nutrient and nitrogen (N) availability, stress levels, and welfare indicators in a welfare environment. A total of 625 eight-day-old male broilers were assigned to five dietary CP levels (control (CON) and 1-4% CP reductions) during the grower (8-21 days) and finisher (22-35 days) periods. The CON diet contained 20% CP in the grower phase and 19% in the finisher phase, while all birds received a 22% CP diet during the starter period (1-7 days). Intriguingly, reducing CP levels in the diet did not significantly affect growth performance. These results may be due to the adequate supplementation of essential amino acids in the diets of all treatments and the compensatory growth observed in the finisher phase. Low-CP diets reduced CP digestibility, N intake, and N excretion, while N retention efficiency improved (p < 0.001). Serum total protein (TP) levels decreased equally with decreasing CP in the diet, and the crude fat content in meat increased linearly (p < 0.01). The litter moisture content and pH decreased with lower CP levels, and the welfare indices (footpad dermatitis (FPD), serum corticosterone, etc.) improved (p < 0.01). In conclusion, an appropriate reduction in CP levels in their diet can enhance broiler welfare by reducing N excretion and improving litter quality without adversely affecting performance.

The Protein/Carbohydrate Ratio in the Diet Affects Zootechnical Performance and the Regulation of Intermediary Metabolism in Juveniles Tambaqui (Colossoma macropomum).

The use of carbohydrates in animal feed is a way to save protein in the diet. This study evaluated the effect of protein/starch ratio on the performance, hepatic metabolism, and body composition of juvenile tambaqui (Colossoma macropomum). Six isoenergetic experimental diets were formulated containing three levels of digestible protein (P: 230, 260 and 290 g kg- 1) and two levels of starch (S: 180 and 280 g kg- 1): P23S18, P23S28, P26S18, P26S28, P29S18 and P29S28. Juveniles tambaqui (N = 288; initial weight = 30.0 ± 3.8 g) were fed experimental diets for 90 days and the zootechnical performance was evaluated. Nine fish from each treatment group were sampled to determine somatic indices, blood metabolites, tissue energy reserves, body composition and activity of key hepatic enzymes. Blood triglycerides, hepatosomatic index, liver and muscle lipids, and hepatic glycogen increased significantly with starch while blood glucose, triglycerides and cholesterol, muscle lipids were significantly impacted by protein levels. Fish-fed S28 had increased feed intake (1714-1829 g; p < 0.0001) and fish-fed diet P26S18 had a higher protein efficiency rate (23.62%; p = 0.0356). Fish fed P23 had lower crude protein retention in the carcass (p = 0.0018) and high lipogenesis and lipid deposition in the muscle (p = 0.0069). These results suggest that dietary carbohydrates have a protein-sparing effect. Tambaqui adapted well to diets containing starch, even at higher levels, resulting in an overall increase in lipogenesis from S18 to S28. Thus, we recommend P26S18 as a cost-effective feed that ensures both zootechnical performance and quality of the final product.

Влияние на две системи на земеделие върху продуктивността и биохимичните качества на лимец и ръж

The experiment was conducted in the period 2019 - 2022 in the experimental field of the Institute of Agriculture in Karnobat. The aim of the research was to determine the influence of two farming systems - organic and conventional on the productivity and biochemical characteristics of rye (Secale cereale L.) and triticale (Triticum monococcum L.). The crop structure and grain yield of rye and einkorn grown in different farming systems depend not only on the studied factor, but also on weather conditions during the growing season of the crops. Organic farming of both crops promotes the formation of higher number of spike-bearing stems compared to conventional farming. We believe that this is a compensatory mechanism, especially under unfavorable climatic conditions. In the case of organically grown rye and einkorn, the plant height, spike length, number of grains in the spike, mass of the grain in the spike were lower than the conventional ones. For organically grown einkorn, despite differences in agro-meteorological conditions, spike length remained stable over the years, but was 18% shorter than that of conventional. The biochemical parameters of the crops differ according to the cultivation method, with conventional rye having a higher percentage of crude protein and lower ash values compared to organic. The lysine content is almost the same in both cultivation methods, but the percentage of crude fiber is higher in conventional farming. Despite lower crude protein levels, organically grown einkorn showed greater stability in ash and fiber content over the years, as well as higher lysine content.

Environmental benefits of crude protein reduction in growing pig diets: is it worth going further?

Nitrogen (N) excretion and emissions can be reduced in fattening pigs by reducing dietary crude protein (CP) levels. Effects of this strategy are well documented for moderate CP reduction, but little literature exists on further CP reduction made possible by free isoleucine, histidine, and leucine. This trial evaluated the effects of 2 levels of reduction in CP on growth performance, N balance, and gaseous emissions. Forty-eight pigs were allocated to 12 gaseous emission-measuring chambers at 28kg live weight. Three dietary treatments (CTRL; -1.2pt; -2.4pt), with a CP content, respectively, of 18.1%, 16.9%, and 15.0% in phase 1 (28 to 48kg) and 16.1%, 15.0%, and 13.8% in phase 2 (48 to 80kg), were fed ad libitum. Growth performance was recorded for each phase. Body lipid and protein composition were analyzed by dual-energy X-ray absorptiometry in 2 animals per chamber at the beginning and end of the trial. These results were used to calculate the N balance. Slurry volume and composition were measured at the end of the trial. Ammonia, methane, and nitrous oxide emissions were recorded continuously. Data were analyzed with a general linear model including the linear and quadratic effect of CP reduction and phase as fixed effects. A trend for a quadratic effect of CP reduction on feed intake was observed (P = 0.085) with a decrease from CTRL to -1.2pt and then an increase with the -2.4pt treatment. Daily gain and gain to feed were improved by the low CP diets in phase 1 but were degraded in phase 2 (phase × CP interaction, P < 0.001) while body composition was not affected. Nitrogen excretion decreased with CP reduction (linear effect, P = 0.023) but tended to plateau with the low CP diets (quadratic effect, P = 0.081). Methane emissions per kg of gain were reduced with CP reduction (linear effect, P = 0.031). Ammonia emissions decreased with CP reduction, mostly in phase 1 (phase × CP interaction, P = 0.015); however, the emission factor (g N-NH3 / g urinary N) was not affected. Nitrous oxide emissions were not affected by CP reduction and its emission factor (g N-N2O / g N) tended to increase (linear effect, P = 0.07). Slurry ammonia-N decreased (linear effect, P < 0.023; quadratic effect, P = 0.049), but other slurry components were not significantly impacted. In this trial, a plateau in N excretion and emission reduction was reached with the -2.4pt treatment. Nevertheless, it is important to study such a reduction in conditions closer to commercial ones.

Kualitas Fisik Silase Jerami Jagung (Zea mays) dengan Campuran Indigofera zollingeriana

Corn straw has the potential as a ruminant feed, but is constrained by low crude protein so it must be combined with Indigofera zollingeriana legumes which have high crude protein. The addition of Indigofera zollingeriana at different levels is expected to increase the crude protein of corn straw silage (Zea mays) and is expected to produce good silage quality. This study aims to determine the physical quality of corn straw silage (Zea mays) and Indigofera zollingeriana in different proportions. The variables observed in this study were the percentage of shrinkage, pH value, percentage of moldy silage, fleigh value, and physical quality (color, aroma, and texture). This experiment was arranged in a Completely Randomized Design (CRD) with 3 treatments and each treatment was repeated 6 times, so there were 18 experimental units, namely P1 = 80% Corn straw + 15% Indigofera zollingeriana + 4% bran + 1% mineral mixture; P2 = 70% Corn straw + 25% Indigofera zollingeriana + 4% bran + 1% mineral mixture; P3 = 60% Corn straw + 35% Indigofera zollingeriana + 4% bran + 1% mineral mixture. The results of the analysis of variance test showed that corn straw silage (Zea mays) with a mixture of Indigofera zollingeriana had no significant effect (P&gt;0.05) on the percentage of moldy silage, fleigh value, and physical quality (color, aroma, texture) but had a significant effect (P&lt;0.05) on the percentage of shrinkage and pH of silage. Based on this study, it can be concluded that the best silage proportion was obtained in the P2 treatment with 70% corn straw + 25% Indigofera zollingeriana + 4% fine bran + 1% mineral mixture, resulting in good quality silage.

The intrauterine effects of a maternal winter diet of either kale or fodder beet on measures of calf stature and bone morphology at birth

ABSTRACT Fodder beet and kale are commonly used winter crops in New Zealand dairy and dairy support farm systems. Fodder beet (FB) is known to have lower crude protein, phosphorus and calcium content compared to kale. The intrauterine effects of feeding FB during late pregnancy on bone growth and development in calves requires attention. This study aimed to examine the intrauterine effects of a maternal diet of either kale or FB on measures of calf stature and bone morphology at birth. In winters 2019 and 2020, two herds of pregnant Friesian × Jersey cows were fed either kale (2019, 2020 n = 20) or FB (2019, 2020 n = 20) supplemented with pasture baleage. Calves born from these mobs were euthanised within ten days of birth and a forelimb and section of rib including the costochondral junction were harvested for peripheral quantitative computed tomography and histological analysis. Calves from the FB treatment had reduced bone density and strength compared to calves from the kale treatment (p < .05). The effect of a nutritional deficit on bone morphology at birth emphasises the importance of sufficient nutrition in pre-calving diets. Future research is required to examine the long-term impact of dam undernutrition on calf growth and production.

The effect of agro-ecological zone on the chemical composition of feed resources in the Gera district, southwest Ethiopia

The poor quality of available feed resources is the major limiting factor for livestock production in Ethiopia. The aim of this study was to determine and compare the chemical composition of major feed resources in three agro-ecological zones (AEZs) of the Gera District, southwest Ethiopia. Three representative samples of natural pasture (Cynodon dactylon, Pavonia schimperiana Hochst and Rhynchosia ferruginea), three indigenous fodder trees and shrubs (IFTSs) (Erythrina abyssinica, Vernonia amygdalina and Maytenus undat), two cultivated forages (Pennisetum purpureum and Pennisetum pedicellatum) and five crop residues (Hordeum vulgare (barley), Zea mays (maize), Sorghum bicolor (sorghum), Triticum aestivum (wheat) and Eragrostis tef (Teff)) were randomly and separately collected from the Highland (HL), midland (ML) and lowland (LL) AEZs. The samples were analyzed for ash, dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), and acid detergent lignin (ADL) content using standard analytical methods. The results showed that AEZ significant (P < 0.05) affected the chemical composition parameters of most of the feed samples. Regardless of the feed sample and AEZs, the mean DM, CP, ash, EE, NDF, ADF, ADL and CF content varied from 89.17% in Pennisetum purpureum to 92.22 ± 0.51 in Erythrina abyssinica, 2.90 ± 0.22% in Triticum aestivum to 10.70 ± 0.52 in Vernonia amygdalina, 7.24 ± 0.19% in Sorghum bicolor to 13.25 ± 0.51% in Pavonia Schimperiana Hochst, 1.33 ± 0.04% in Triticum aestivum to 2.39 ± 0.15% in Maytenus undata, 57.65 ± 1.19% in Erythrina Abyssinica to 79.16 ± 1.04% in Triticum aestivum, 34.57% in Pennisetum purpureum to 59.41 ± 0.98% in Sorghum bicolor, 8.15 ± 0.62% in Rhynchosia ferruginea to 12.65 ± 0.57% in Triticum aestivum and 37.51% in Pennisetum pedicelatum to 69.93 ± 0.65% DM in Triticum aestivum, respectively. It was observed that IFTSs had the highest CP and the lowest NDF, implying their potential for protein supplement, whereas crop residues had the lowest CP and the highest NDF, indicating the need for their treatment using urea or supplementing animals with protein source feeds, especially during the dry season. In conclusion, AEZ has an influence on the chemical composition traits of feed resources attributed to its effects on the microclimate conditions that affect plant growth and maturation in the study sites.

Chemical Composition and In Vitro Protein Digestibility of Duckweed and Feed Ingredients

Duckweed is an aquatic floating plant with the potential to be used as animal feed due to its richness in protein, amino acids, starch, vitamin and minerals. Furthermore, duckweed has a high growth rate and reproducibility. Therefore, this research aimed to determine the chemical composition and in vitro protein digestibility of duckweed (Lemna, Wolffia and Spirodela) in comparison to other feed ingredients. The chemical composition was determined through proximate analysis including dry matter (DM), crude protein (CP), ether extract (EE), crude fiber (CF), ash and nitrogen free extract. The in vitro protein digestibility procedure simulates conditions similar to those in the swine digestive tract using synthetic enzymes to control pH, temperature and digestion time. In the results of chemical composition, Lemna and Wolffia were classified as protein sources, with high CP content (221.87 and 442.65 g/kg DM, respectively) and low CF content (63.30 and 109.11 g/kg DM), whereas Spirodela had low CP content (179.64 g/kg DM) and CF content (170.57 g/kg DM). The EE content in duckweed amounted to 16.74, 46.23 and 52.47 g/kg DM for Wolffia, Spirodela and Lemna, respectively. Additionally, high ash content was observed in Spirodela (212.40 g/kg DM), Wolffia (149.34 g/kg DM) and Lemna (142.06). For standardized ileal digestibility (SIDCP), the SIDCP of all feed ingredients were within the range of 32 to 96 %. With regard to duckweed, Lemna (72 %) showed significantly higher (p &lt; 0.05) SIDCP compared to Wolffia (69 %) and Spirodela (39 %) due to the low contents of CF and ash. Based on nutritional values, Lemna and Wolffia were grouped with corn DDGS and brewer’s grain, indicating their potential as animal feed for sustainable livestock production. HIGHLIGHTS Duckweed exhibited high protein content, ranging from 179.64 to 65 g/kg dry matter. For in vitro protein digestibility, Lemna and Wolffia had high true digestibility, amounting to 79 and 75 %, respectively. Based on nutritional values, Lemna and Wolffia were grouped with corn DDGS and brewer’s grain, indicating their potential as animal feed for sustainable livestock production. GRAPHICAL ABSTRACT

Growth Performance and Nutrient Utilization of Balami and Yankasa Rams Fed Leucaena leucocephala and Dried Poultry Manure Based Concentrates Diets

In this work, two feed concentrates—dried poultry manure concentrate (DPMC) and Leucaena leucocephala-based concentrate (LLBC)—fed to rams of two breeds (Yankasa and Balami) were assessed for their proximate composition, digestibility, and nitrogen utilization. In comparison to LLBC, which has more crude protein (15.26%), lower fiber (12.33%), and somewhat higher ether extract (3.21%), DPMC has higher dry matter (90.54%) and fiber (20.55%) but lower crude protein (13.58%) and ether extract (3.84%). Additionally, LLBC exhibits a greater nitrogen-free extract (46.23%) and ash content (8.45%) in comparison to DPMC, which results in a slightly higher total energy content (18.96 MJ/kg against 17.76 MJ/kg). Breed, feed, or breed × feed interaction impacts on performance indicators are not significant (P&gt;0.05). Breed effects (P&lt;0.05) were noted on digestibility, with Balami rams outperforming Yankasa rams in the digestibility of dry matter, crude protein, and nitrogen-free extract. LLBC increased(P&lt;0.05) the digestibility of nitrogen-free extract and dry matter compared to DPMC. The findings indicate that as compared to Yankasa rams fed LLBC, Balami rams fed DPMC showed greater (P&lt;0.05) digestibility of dry matter, crude protein, and nitrogen-free extract. The effects of breed, feed, and breed × feed interaction on nitrogen utilization were significant (P&lt;0.05). Breed has a significant (p&lt;0.05) impact on nitrogen intake, digestion, and retention; Yankasa has greater values than Balami. In comparison to DPMC, LLBC resulted in increased nitrogen intake and retention. Interestingly, the interaction effect reveals that whilst Balami rams retained more nitrogen with DPMC, Yankasa rams retained more nitrogen with LLBC. With implications for optimizing feed strategies based on breed-specific requirements, this study highlights the impact of both feed type and breed on nutritional efficiency.

PSII-20 Effect of increasing glycine equivalent in low crude protein diets on growth performance in broiler chickens raised under multiple stress conditions

Abstract The objective of the current experiment was to investigate the effects of increasing glycine (Gly) equivalent in low crude protein (LCP) diets on growth performance in broiler chickens raised under multiple stress (MS) conditions. Ross 308 broiler chickens (n = 450; 22 d of age) were randomly allotted to 1 of 6 treatments with 6 replicates in a 2 × 3 factorial arrangement. The first factor included two different environmental conditions (normal condition vs. MS condition) and the second factor included three dietary treatments (CON, control diets; LCP, low crude protein diets; LCP+Gly, LCP diets with Gly supplementation). Birds in normal conditions were raised under recommended environmental conditions (22 ± 0.9°C and 53.6 ± 5.99 %) with low stock density (SD; 16.9 birds/m2). Birds in MS conditions were exposed to a cyclic heat stress condition (32 ± 0.1°C for 8 h/d and 26°C ± 0.3°C for the remaining time) with high SD (25.3 birds/m2). The average relative humidity was 37.9 ± 4.94%. In addition, 15 birds per cage were assigned in MS conditions to increase SD, whereas 10 birds per cage were assigned in normal conditions. The treatment diets included CON diets with adequate energy, crude protein (19.50% CP and 1.15% Gly equivalents), and other nutrients recommended for growing broiler chickens and LCP diets with low CP content (16.50% CP and 1.15% Gly equivalents) but adequate other nutrients. The LCP+Gly diets had increasing concentrations of Gly equivalents (17.19% CP and 1.73% Gly equivalents) by Gly supplementation to LCP diets. The diets and water were provided ad libitum throughout the experiment. Experiment lasted for 16 d from 22 d to 37 d of age. At the conclusion of the study, growth performance including body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) was determined. All data were analyzed by 2-way ANOVA in a completely randomized design using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Results indicated that no interactions between environmental conditions and dietary treatments were observed for all growth performance measurements (Table 1). For the main effects, as expected, MS conditions decreased (P &amp;lt; 0.001) growth performance of broiler chickens, regardless of dietary treatments. The LCP diets increased (P &amp;lt; 0.05) FI and FCR as compared with CON diets, regardless of environmental conditions. However, LCP+Gly diets decreased FI (P &amp;lt; 0.05) and tended to decrease FCR (P = 0.076) as compared with LCP diets. In conclusion, either MS conditions or LCP diets impair growth performance in broiler chickens with no significant interaction. However, increasing Gly equivalents by Gly supplementation to LCP diets are likely to improve feed efficiency in broiler chickens regardless of stress environments.

470 Reducing crude protein levels with amino acid supplementation in the finishing diets of heavy Duroc sire line pigs: Effects on growth performance and nitrogen balance in males and females

Abstract Nutrition represents 70% of pig production costs, particularly protein; then, decreasing protein costs is of capital importance. Reducing crude protein (CP) contents to levels below recommended whilst supplementing with amino acids (AAs) is an interesting strategy to reduce costs without decreasing production performances with environmental benefits. It has been conducted essentially in lean genotypes during the growth stage. Few studies address heavy genotypes or differences between males and females during the finishing period. Our objective is to study productive performances of heavy [Duroc X (Landrace X Large-White)] male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation, hypothesizing that both sexes will equally be affected. In total, 60 males and 60 females were used. At 9 wk of age, animals were allotted in split-sex pens (6 pigs/pen, 0.9 m2/animal) with water and dry feed ad libitum. At 15 wk of age, when pigs weighed an average of 68 kg, two isoenergetic diets with different CP levels were provided (145 and 125 g CP/kg, control and low-CP) during the last 42 d of fattening, under the ideal protein concept. In the low-CP diet, crystalline AAs were added. Feed intake was measured daily, and animals were weighed every 3 wk to calculate average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) and N balance on d 21 and 42. Data were analyzed using the simple least squares models that included dietary treatment and sex and their interaction as fixed effects with the pen as the experimental unit. At d 21, animals weighed 90 to 95 kg with males being 5 to 6 % heavier (P &amp;lt; 0.01). No significant differences were recorded regarding diet. The same difference (P &amp;lt; 0.001) was recorded at day 42, with males (119-122 kg) being 7.25% heavier than females in both treatments. Males had 16% higher ADGs than females in both treatments (P &amp;lt; 0.0001) No differences were recorded for ADFI as a consequence of sex for both diets. FCRs were higher in females of both nutritional treatments (P &amp;lt; 0.0001). Retained N was 22% greater in males than in females for both dietary treatments. The N efficiency was greater in Low CP males by comparison with low CP females and control males, whereas control CP females had decreased N efficiency compared with all other experimental groups. Results demonstrate that the 20g/kg CP reduction supplemented with AAs can efficiently be used in heavy Duroc sire line genotypes during the finishing phase without a decrease in production parameters with females having poorer growth performances than males, whereas N efficiency was impaired when females had no limiting dietary CP.

478 Impact of crude protein and phosphorus deficiencies on liver mitochondrial content and transcriptome in growing Merino wethers

Abstract In grazing systems in Northern Australia, crude protein (CP) and phosphorus (P) availability varies, affecting ruminant production due to voluntary reduced intake and therefore body weight (BW) gain. We were interested in understanding metabolic regulation in this model system, both in terms of a) identifying key tissues, and b) detecting any modifications in mitochondrial physiology, given the central role of this organelle in bioenergetic homeostasis. Merino wethers (n = 24) were subjected to three dietary regimens: High CP, High P, (Control), Low CP, Low P (Deficient), and High CP, High P, with restricted feed intake (Restricted). Mitochondrial DNA (mtDNA) copy numbers, indicative of mitochondrial content, were measured via qPCR. Transcriptomic analyses through RNA sequencing targeted mitochondria-associated gene expression changes and pathways, using the MitoCarta 3.0 database. There was a significant decrease of mtDNA copy numbers in the liver of sheep under either Deficient and Restricted diets (P &amp;lt; 0.01), with as much as a 2-fold difference between the Control and Deficient diets. This may suggest reduced mitochondrial biogenesis as an adaptation to decreased energy intake. When compared with the Control group, both the Deficient and Restricted groups upregulated pathways related to vitamin metabolism (Log2FC: 0.231 and 0.449) and folate and 1-C metabolism (Log2FC: 0.409 and 0.706). However, impacted pathways shared between these two comparisons (Control v Deficient, Control v Restricted) also include choline and betaine metabolism, amino acid metabolism, and glycine metabolism, which suggests similar mechanisms being impacted by decreased energy intake, regardless of whether it is due to satiety from nutrient deficiency or restricted feed intake. Notably, the creatine metabolism pathway was uniquely upregulated in the Restricted group compared with the Deficient group (Log2FC: 0.114), although the CKMT2 gene was upregulated in the Restricted group compared with both the Control and Deficient group (Log2FC: 1.30 and 0.879). Additionally, the SLC25A family pathway, responsible for mitochondrial metabolite transport, was found to be upregulated in the Restricted group when compared with both Control and Deficient groups (Log2FC: 0.33 and 0.865). Overall, this study demonstrated a pronounced decrease in mitochondrial content in the liver of growing Merino wethers subjected to nutritional deficiencies and feed restriction. Multiple metabolic pathways were shared between the comparisons of the Control diet group to both Deficient and Restricted nutritional treatments. However, the SLC25A transporter family pathway was uniquely upregulated in the Restricted group compared with either an optimal or deficient diet. The regulation of these metabolic pathways is a subject of further study that may represent a systemic response to maintain homeostasis while undergoing significantly lower energy intake, with implications for animal growth, tissue deposition, and energetic maintenance. Understanding distinctions in the response to feed restriction and nutrient deficiency induced reduction in intake may help improve production strategies for ruminants grazing in these conditions.

Biomass yield, crude protein yield and nitrogen use efficiency over nine years in annual and perennial cropping systems

Emerging biorefinery technologies can lead to new applications and new markets for various types of crop biomass. This may allow significant changes in agricultural production from crop rotations dominated by annual grain and seed crops towards annual or perennial cropping systems composed with the aims of higher biomass yield and environmental sustainability. In this study, we investigated 7 annual and 7 perennial cropping systems on a sandy loam soil, with large differences in N fertilization. Yield of dry matter (DM) and crude protein (CP) was measured over nine growing seasons from 2013 to 2021. A conventional four-year cash crop rotation with cereals and winter oil seed rape served as a reference and achieved mean annual yields of DM and CP of 10.5 and 0.85 Mg ha−1 y−1, respectively, across the nine years. Continuous maize and triticale had significantly higher DM and CP yields, with 57 and 15 % increases in DM yield compared to the reference crop rotation, respectively. Optimized four-year crop rotations with various annual crops including triticale, maize, beet, hemp or faba bean and various intermediate crops achieved 51–84 % and 42–78 % higher yield of DM and CP, respectively. Perennial cropping systems with festulolium and tall fescue with three or four harvests per year achieved 63–65 % higher DM yield and 192–200 % higher CP yield (2.47–2.55 Mg ha−1 y−1) compared to the cash crop rotation. Perennial cropping systems with miscanthus and willow had high DM but low CP yield. As a measure of nitrogen use efficiency, partial factor productivity of DM yield (PFPDM) and CP yield (PFPCP) were calculated, and both varied significantly between cropping systems, with highest PFPDM for M. × giganteus and willow (114–192 kg DM kg N−1) and lowest for festulolium and tall fescue (38–40 kg DM kg N−1). PFPCP was highest for the optimized crop rotations (6.88–7.94 kg CP kg N−1) and lowest for miscanthus (2.94–4.98 kg CP kg N−1). Across 12 of the cropping systems, which included both protein crops and lignocellulosic crops, there was a non-linear DM yield response to N fertilization rate with PFPDM decreasing from 134.9 to 37.2 kg DM kg N−1 when increasing the N rate from 50 to 500 kg ha−1 y−1. On the other hand, there was a linear CP yield response and, therefore, a constant PFPCP of 5.94 kg CP kg−1 N across N fertilization rates. The results clearly indicate that cropping systems can be modified to achieve higher DM and CP yields but also that choice of cropping system and optimal N fertilization may need adjustment depending on the use of the harvested biomass, the possibilities for biorefining into various components and products as well as the economic value of the components.

Different dietary branched-chain amino acid ratios, crude protein levels, and protein sources can affect the growth performance and meat yield in broilers

Balanced ratios of branched-chain amino acids (BCAAs) can enhance chicken growth, immunity, and muscle synthesis. However, these ratios can be affected by changes in crude protein (CP) levels or the substitution of protein sources, leading to BCAA antagonism. This, in turn, can have a negative impact on chicken growth. In Experiment 1, a total of 960 0-d-old male Cobb 500 broilers were divided into 6 treatments with 8 replicates. Three different BCAA ratios were used in High or Low CP diets as follows: 1) Low Leu group (Low level of leucine with increased valine and isoleucine levels), 2) Med Leu group, and 3) High Leu group (High level of leucine with reduced valine and isoleucine levels) for a total of 6 diets. In Experiment 2, a total of 640 0-d-old male Cobb 500 broilers were divided into 4 treatments with 8 replicates. The four diets had either High or Low CP and one of two protein sources with the same medium levels of BCAAs: 1) the soybean meal (SBM) group, which had SBM as the main protein source (protein bound AA), and 2) the wheat middlings with non-bound AAs (WM+AA) group (non-bound AA), which had additional non-bound AAs to replace SBM. The High Leu diet had a negative effect on overall growth performance, carcass weight, breast muscle weight, and body mineral composition compared to the Low Leu and Med Leu groups, particularly in the High CP diet (P < 0.05). The SBM group showed increased growth performance, breast muscle weight, expression levels of genes promoting muscle growth, and improved bone mineral composition compared to the WM+AA group, and the High CP group intensified the negative effect of the WM+AA diet (P < 0.05). In summary, balanced BCAA ratios and SBM-based diets have positive effects on chicken growth and muscle accretion, whereas excessive leucine and non-bound AA levels in the diets may negatively affect growth performance and meat yield in chickens.

Effects of Fermented Herbal Extract as a Phytobiotic on Growth Indices, Moulting Performance, and Feed Utilization of Juvenile Tiger Shrimp (Penaeus monodon Fabr.)

The objective of this study was to investigate the impact of adding fermented herbal extracts (FHE) derived from mulberry leaf (Morus alba), Javanese turmeric (Curcuma xanthorrhiza), and fingerroot (Boesenbergia rotunda) to the diet of tiger shrimp (Penaeus monodon) on their growth, moulting performance, feed efficiency, and nutrient retention. The main feed used in this trial was a commercially manufactured pellet; then, five different doses of FHE supplementation were used: 0 mg/kg feed (P0, control), 50 mg/kg feed (P1), 100 mg/kg feed (P2), 150 mg/kg feed (P3), and 200 mg/kg feed (P4). Weight gain, average daily gain, and length gain of shrimps fed P2 were significantly higher than that of those fed the control diet. A similar result was observed in moulting performance. The application of P2 showed superior results in enhancing the feed efficiency of cultured shrimp. Thus, the protein and energy retention of P. monodon was significantly better in P2 treatment groups. P0 had the lowest crude protein, while shrimp on the P2 and P3 diets had the highest crude protein content of any treatment group. Crude lipid content was lower in shrimp fed diets supplemented with FHE compared to those fed the control diet. In addition, higher energy contents were found in P1 and P2 treatment groups. Based on the findings, it is recommended that the juvenile tiger shrimp diet contain 100 mg/kg of FHE for the best effects.

Impact of lowering nitrogen content in pig manure through low crude protein diets on anaerobic digestion process stability, biogas yields, and digestate composition

Lowering crude protein in pig diets can reduce nitrogen (N) excretion and alter manure characteristics. Anaerobic digestion (AD) offers potential for converting pig manure into biogas and bio-based fertilizers (i.e., digestate). However, limited research exists on the effects of N content in pig manure on AD when pigs are fed diets with varying crude protein levels. This study investigated how lowering N content in pig manure through low crude protein diets may affect AD process stability, biogas generation, and digestate properties. Manures from different dietary treatments, named as control (CON), low N (LN), and very low N (VLN), with Total Kjeldahl Nitrogen concentrations of 5.87, 5.42, and 5.15 g/L, respectively, were investigated. Daily biogas production, composition (CH4, CO2, and H2S), and digestate properties were monitored over 13 fed-batch cycles (25 ± 4 days per cycle). The experiment was conducted at 20 ± 1 °C, a condition suited for milder climate regions, using six single-stage digesters operated in sequencing fed-batch mode. Data were analyzed by ANOVA using PROC MIXED with repeated measures. Results showed that the differences in N content in pig manure due to the three dietary treatments had a limited impact on biogas generation, with specific methane yields remaining similar over time. CH4 concentrations remained stable between 60 and 65 %, ensuring high-quality biogas despite dietary variations. Differences between treatments became more pronounced with increased organic loading rates (OLRs) due to variations in the amount of volatile solids fed. AD also remained stable (Total Volatile Fatty Acids/Total Alkalinity <0.25) even at an OLR of 2.15 g of chemical oxygen demand L−1 day−1, highlighting AD's robustness at lower temperatures. Digestate samples contained essential minerals beneficial for plant growth. More research is needed to explore varied manure compositions and feeding strategies to better understand the interactions of animal nutrition with AD.

Clinical characteristics and prognosis of early diagnosed Wilson's disease: A large cohort study.

Few studies have focused on the outcomes of Wilson's disease (WD) diagnosed before age of 5 years. This study aimed to summarize the clinical features of early diagnosed WD and analyse treatment outcomes and the risk factors associated with treatment failure. A total of 139 children confirmed with WD before 5 years were enrolled in this study. Only patients with follow-up over 1 year were analysed with Kaplan-Meier survival analysis. The composite outcomes included death, progression to liver failure or acute hepatitis, development of renal or neurological symptoms and persistent elevation of alanine aminotransferase (ALT). The treatment failure was defined as occurrence of at least one of above outcomes. Among 139 WD patients at diagnosis, two (1.4%) WD patients presented with symptomatic liver disease, whereas 137 (98.6%) were phenotypically asymptomatic, including 135 with elevated ALT and 2 with normal liver function. Median serum ceruloplasmin (Cp) was 3.1 mg/dL, and urinary copper excretion was 87.4 μg/24-h. There were 71 variants identified in the the copper-transporting ATPase beta gene, and 29 were loss of function (LOF). 51 patients with LOF variant were younger at diagnosis and had lower Cp than 88 patients without LOF. Among 93 patients with over 1 year of follow-up, 19 (20.4%) received zinc monotherapy, and 74 (79.6%) received a zinc/D-penicillamine combination therapy. 14 (15.1%) patients underwent treatment failure, and its occurrence was associated with poor compliance (p < .01). Cp is a reliable biomarker for early diagnosis, and zinc monotherapy is an effective treatment for WD during early childhood. Good treatment compliance is critical to achieve a favourable outcome.

High-level L-Gln compromises intestinal amino acid utilization efficiency and inhibits protein synthesis by GCN2/eIF2α/ATF4 signaling pathway in piglets fed low-crude protein diets

Gln, one of the most abundant amino acids (AA) in the body, performs a diverse range of fundamental physiological functions. However, information about the role of dietary Gln on AA levels, transporters, protein synthesis, and underlying mechanisms in vivo is scarce. The present study aimed to explore the effects of low-crude protein diet inclusion with differential doses of L-Gln on intestinal AA levels, transporters, protein synthesis, and potential mechanisms in weaned piglets. A total of 128 healthy weaned piglets (Landrace × Yorkshire) were randomly allocated into four treatments with four replicates. Pigs in the four groups were fed a low-crude protein diet containing 0%, 1%, 2%, or 3% L-Gln for 28 d. L-Gln administration markedly (linear, P < 0.05) increased Ala, Arg, Asn, Asp, Glu, Gln, His, Ile, Lys, Met, Orn, Phe, Ser, Thr, Tyr, and Val levels and promoted trypsin activity in the jejunal content of piglets. Moreover, L-Gln treatment significantly enhanced concentrations of colonic Gln and Trp, and serum Thr (linear, P < 0.01), and quadratically increased serum Lys and Phe levels (P < 0.05), and decreased plasma Glu, Ile, and Leu levels (linear, P < 0.05). Further investigation revealed that L-Gln administration significantly upregulated Atp1a1, Slc1a5, Slc3a2, Slc6a14, Slc7a5, Slc7a7, and Slc38a1 relative expressions in the jejunum (linear, P < 0.05). Additionally, dietary supplementation with L-Gln enhanced protein abundance of general control nonderepressible 2 (GCN2, P = 0.010), phosphorylated eukaryotic initiation factor 2 subunit alpha (eIF2α, P < 0.001), and activating transcription factor 4 (ATF4) in the jejunum of piglets (P = 0.008). These results demonstrated for the first time that a low crude protein diet with high-level L-Gln inclusion exhibited side effects on piglets. Specifically, 2% and 3% L-Gln administration exceeded the intestinal utilization capacity and compromised the jejunal AA utilization efficiency, which is independent of digestive enzyme activities. A high level of L-Gln supplementation would inhibit protein synthesis by GCN2/eIF2α/ATF4 signaling in piglets fed low-protein diets, which, in turn, upregulates certain AA transporters to maintain AA homeostasis.