Metabolism In Lambs Research Articles

Effect of contrasting water-soluble carbohydrate to crude protein ratio’s in perennial ryegrass on nitrogen metabolism in lambs

ABSTRACT The effect of high and low water-soluble carbohydrate (WSC) to crude protein (CP) ratios on nitrogen balance in lambs was evaluated. Ryegrasses containing either 35.4% WSC and 12% CP (High WSC) or 14.8% WSC and 23.8% CP (High N) were harvested, frozen and fed to lambs in metabolism crates. These contrasts in WSC and CP delivered diets with markedly different WSC:CP ratios (3.17:1 and 0.70:1). These ratios were higher than those reported in ryegrass previously. There was no difference in urinary nitrogen concentration (0.46 vs 0.48 g/l) but as the total urinary volume was higher on the High N diet (4.2 vs 1.5 l/d, P < 0.001), the end result was that more N was excreted in the urine on the high N diet (18.8 vs 7.3 g/d, P < 0.001). However, the proportion of nitrogen intake that was excreted in urine and faeces was higher on the High WSC diet so there was no evidence that a high WSC forage diet improved nitrogen utilisation.

Effect of fermented total mixed rations on rumen microbial communities and serum metabolites in lambs

AbstractBackgroundDiet regulates rumen microbiota, which in turn affects animal health. The present study evaluated the response of rumen microbiota and the immune system of lambs to a fermented total mixed ration diet.MethodsA total of 30 lambs were assigned into two groups: a group fed an unfermented high‐fiber diet (total mixed ration [TMR]) and a group fed an fermented low‐fiber diet (fermented TMR [FTMR]).ResultsThe results showed that FTMR markedly (p &lt; 0.05) increased average daily gain and dry matter intake compared to TMR. The FTMR diet increased the relative abundance of Veillonellaceae_UCG‐001 and decreased the diversity of undesirable microbiota despite stable overall microbial community diversity. Serum metabolomic analysis combined with enrichment analysis showed that serum metabolites were affected by the FTMR and metabolic pathways, and the FTMR diet significantly (p &lt; 0.05) influenced amino acid metabolism of lambs. There was a decrease in inflammatory factors in the FTMR treatment, indicating that inflammatory factors followed the same trajectory as changes in microbial community structure and function.ConclusionsOverall, the FTMR diet reduced undesirable microbiota diversity, thereby regulating host amino acid metabolism and improving immune status.

Impacts of a highly pathogenic ovine Eimeria ovinoidalis on the growth of Hu lambs

The apicomplexan Eimeria ovinoidalis is distributed worldwide. It can cause clinical coccidiosis, which is one of the most pathogenic species in sheep, reducing growth rates and resulting in significant economic losses in the industry. Its principal clinical sign is profuse diarrhoea in young animals. In this study, we established a model of E. ovinoidalis infection in lambs to understand its pathogenicity and evaluate the gut microbiota and fecal metabolite profiles. Specifically, we observed a significant shift in the abundance of bacteria and disrupted metabolism in lambs. Especially during the peak period of excrete oocysts, it promoted the reproduction of some harmful bacteria in Proteobacteria and Actinobacteriota, and reduced the abundance of beneficial bacteria such as Lachnospiraceae and Rikenellaceae. In the later stage of the patent period, the abundance of harmful bacteria in the intestine decreased, the abundance of beneficial bacteria which could produce anti-inflammatory substances began to increase, and the abundance and diversity of intestinal flora also tended to parallel with the control group. Coccidia infection could lead to the increase of differential metabolites and metabolic pathways between infected and control group, but the difference decreased with time. During the peak period of excrete oocysts, although the antimicrobial metabolites such as Lividamine were up-regulated, the excess of these metabolites could still induce the production of endotoxin, while Butanoic acid and other anti-inflammatory metabolites decreased significantly. A metabolomics analysis showed that E. ovinoidalis infection altered metabolites and metabolic pathways, with biosynthesis of unsaturated fatty acids, Teichoic acid biosynthesis and Butanoate metabolism as the major disrupted metabolic pathways. Details of the gut microbiota and the metabolome after infection with E. ovinoidalis may aid in the discovery of specific diagnostic markers and help us understand the changes in parasite metabolic pathways.

Effects of lactic acid bacteria on protein metabolism of Sunit lamb

To investigate the effect of adding lactic acid bacteria (LAB) to Sunit lambs’ diet on their protein metabolism, 18 3-month-old Sunit sheep were randomly divided into two groups (Group C (non-feeding of LAB) and Group L (feeding of LAB)) for a 90 d feeding trial. After the animals were slaughtered, we measured several key factors, including basal indices, amino acid composition, protein metabolism enzyme activity, and protein metabolism-related gene expression. There were nine replications of each group. The data show that LAB had a significant effect on the intramuscular fat (IMF) content (P<0.001). The composition of amino acids in the serum and mutton was improved by the addition of LAB. The addition of LAB led to a significant increase in the expression of genes related to AKT serine/threonine kinase 1 (Akt1), mammalian target of rapamycin (mTOR), p70 ribosomal protein S6 kinase (p70S6K1), and eukaryotic initiation factor 4E (eIF4E) protein synthesis (P<0.05), while the expression of all genes related to protein catabolism was reduced. Thus, dietary LAB can increase IMF content, improve amino acid composition, regulate protein metabolism in lambs, and provide a new way and theoretical basis for dietary management to improve meat quality in housed sheep.

Asociación de la expresión de genes con metabolitos sanguíneos y perfil de ácidos grasos en corderos

Some agricultural byproducts can be used as viable alternatives in animal feed. Therefore, the effect of the inclusion of avocado meal and sunflower oil on the profile of fatty acids, blood metabolites and the expression of genes associated with lipid metabolism in lambs was evaluated. Three treatments were evaluated: 0 % control, 10 % avocado meal and 10 % sunflower oil for 84 days. It was found that including avocado meal in the diet increased the amount of blood glucose and also globulin, but decreased creatinine and Glutamic Oxaloacetic Transaminase, compared to the addition of sunflower oil where the content of cholesterol, triglycerides, and VLDL decreased. and R A/G. There was no difference for muscle fat percentage. The concentration of fatty acids C20:0, C20:1 and C23:0 was lower with avocado meal, without affecting the MUFA and UFA values, the UFA/SFA ratio and the saturation index. The inclusion of avocado meal caused a change in the expression of the ACACA, FASN, SCD, FASBP3, PPARG and SREBF1 genes in the Longisimus thoracis muscle, there was a positive association between glucose and the FASBP3 gene, also of HDL with the PPARG gene, MUFA, proteins and indices of desaturation of fatty acids were associated with genes such as SCD, FASN, SREBF1 and ACACA The inclusion of avocado meal is an alternative to modify genetic expression, also to reduce very low density cholesterol values in the blood.

Genome wide transcriptome analysis provides bases on hepatic lipid metabolism disorder affected by increased dietary grain ratio in fattening lambs

BackgroundThe liver is a principal metabolic organ and has a major role in regulating lipid metabolism. With the development of rapidly fattening livestock in the modern breeding industry, the incidence of hepatic steatosis and accumulation in animals was significantly increased. However, the molecular mechanisms responsible for hepatic lipid metabolic disturbances in a high concentrate diet remain unclear. The objective of this study was to evaluate the effects of increasing concentrate level in a fattening lamb diet on biochemical indices, hepatic triglycerides (TG) concentration, and hepatic transcriptomic profiles. In the present study, 42 weaned lambs (about 3 ± 0.3 months old) were randomly assigned to the GN60 group (60% concentrate of dry matter, GN60, n = 21) or GN70 group (70% concentrate of dry matter, n = 21) for a 3-months feeding trial.ResultsNo difference was observed in the growth performance or plasma biochemical parameters between the GN60 group and the GN70 group. The hepatic TG concentration was higher in the GN70 group than GN60 group (P < 0.05). Hepatic transcriptomic analysis showed that there were 290 differentially expressed genes identified between GN60 and GN70 groups, with 125 genes up-regulated and 165 genes down-regulated in the GN70 group. The enriched Gene Ontology (GO) items and KEGG pathways and protein–protein interaction (PPI) network of differentially expressed genes (DEGs) revealed that the majority of enriched pathways were related to lipid metabolism. Further analysis revealed that the fatty acid synthesis was up-regulated, while fatty acid transport, oxidation, and TG degradation were down-regulated in the GN70 group when compared with the GN60 group.ConclusionsThese results indicated that GN70 induced excess lipid deposition in the liver of lambs during the fattening period, with high synthesis rates and low degradation rates of TG. The identified mechanisms may help understand hepatic metabolism in lambs with a high concentrate diet and provide insight into decreasing the risk of liver metabolism disorder in animals.

P-042 Oxidative metabolism in lambs from ewes supplemented in pregnancy and that were supplemented with vitamin D 24 hours of birth

P-042 Oxidative metabolism in lambs from ewes supplemented in pregnancy and that were supplemented with vitamin D 24 hours of birth

Effects of inoculation with active microorganisms derived from adult goats on growth performance, gut microbiota and serum metabolome in newborn lambs.

This study evaluated the effects of inoculation with adult goat ruminal fluid on growth, health, gut microbiota and serum metabolism in lambs during the first 15 days of life. Twenty four Youzhou dark newborn lambs were selected and randomly distributed across 3 treatments (n = 8/group): autoclaved goat milk inoculated with 20 mL sterilized normal saline (CON), autoclaved goat milk inoculated with 20 mL fresh ruminal fluid (RF) and autoclaved goat milk inoculated with 20 mL autoclaved ruminal fluid (ARF). Results showed that RF inoculation was more effective at promoting recovery of body weight. Compared with CON, greater serum concentrations of ALP, CHOL, HDL and LAC in the RF group suggested a better health status in lambs. The relative abundance of Akkermansia and Escherichia-Shigella in gut was lower in the RF group, whereas the relative abundance of Rikenellaceae_RC9_gut_group tended to increase. Metabolomics analysis shown that RF stimulated the metabolism of bile acids, small peptides, fatty acids and Trimethylamine-N-Oxide, which were found the correlation relationship with gut microorganisms. Overall, our study demonstrated that ruminal fluid inoculation with active microorganisms had a beneficial impact on growth, health and overall metabolism partly through modulating the gut microbial community.

Essential oil from Arnica montana alters the protein metabolism in lambs fed with high-concentrate diets

The objective of this study was to evaluate the effect of essential oil (EO) from Arnica montana as an additive on nutrient intake and digestibility, nitrogen balance, and rumen fermentation characteristics in feedlot lambs. Five ruminally cannulated Dorper × Santa Inês ram lambs, castrated, with 50.6 ± 1.19 kg of initial BW and 14.6 ± 1.28 month-old were distributed in a 5 × 5 Latin square design. All lambs were fed a basal diet (160.5 ± 3.06 g/kg DM of CP) containing 90 % concentrate and 10 % forage (Coastcross hay) to which the following 5 treatments were applied: 1. 0 mg/kg DM of OE from Arnica montana (A0), 2. 450 mg/kg DM of OE from Arnica montana (A450), 3. 900 mg/kg DM of OE from Arnica montana (A900), 4. 1350 mg/kg DM of OE from Arnica montana (A1350), 5. diet with 25 mg/kg DM of sodium monensin (positive control – MON). The levels of EO from Arnica montana did not alter the dry matter intake (DMI) and nutrient intake (DM, OM, CP, EE, NDF, ADF, NFC, and TDN). There was higher DM and nutrient intake for the EO from Arnica montana diets compared to MON (P < 0.05). For the comparison between MON vs. A0, there was a lower DMI and nutrients intake for MON (P < 0.05). Crude protein digestibility increased linearly (P = 0.03) in response to increasing levels of EO from Arnica montana in the diets. However, the digestibility of the other nutrients was not altered by the inclusion of EO from Arnica montana. There was no difference in nutrient digestibility for comparison between diets containing EO from Arnica montana vs. MON; and MON vs. A0. The inclusion of EO from Arnica montana in the diet linearly decreased (P = 0.03) nitrogen (N) in the urine, which was associated with a linear decrease (P = 0.03) in rumen ammonia concentration. The EO from Arnica montana contents linearly increased N retention (g/kg N intake and g/kg N absorption; P < 0.05). Diets with EO from Arnica montana had higher N intake and N excretion in urine compared to MON (P < 0.05). There was increased N retention for the diets with EO from Arnica montana when compared to MON (P = 0.02). In the contrast between MON vs. A0, there was lower N intake and lower N excretion via urine for MON (P < 0.05). The EO from Arnica montana contents conferred a quadratic effect (P = 0.03) on the molar ratio of acetate, with a lower concentration for A450. The total and individual concentrations of the other short-chain fatty acids (SCFA) were not affected by the inclusion of EO from Arnica montana. Total and individual SCFA concentrations did not differ between diets containing EO from Arnica montana vs. MON, nor between MON vs. A0. Rumen pH was not influenced by the inclusion of EO from Arnica montana in the diet, but there was a quadratic effect (P = 0.02) on the area under pH 5.5, with a greater area under 5.5 for A450. Diets with EO from Arnica montana had lower rumen pH when compared to MON (P = 0.01). The MON diet increased rumen pH compared to A0 (P < 0.01), this result contributed to a lower area under pH 5.5 and a higher total pH area for MON (P < 0.05). In conclusion, the 1350 mg/kg DM of EO from Arnica montana was the most promising, especially for the increased dietary N use efficiency, even when compared with sodium monensin.

Effects of dietary guanidinoacetic acid on growth performance, guanidinoacetic acid absorption and creatine metabolism of lambs.

Guanidinoacetic acid (GAA) is the only precursor for the creatine synthesis of vertebrates. Creatine (Cr) and phosphocreatine (PCr) are able to provide energy for the rapid growth and development of the muscle tissue. This study evaluated the effects of dietary different levels GAA on growth performance, GAA absorption and creatine metabolism of lambs. Twenty-four 3-month-old healthy Kazakh male lambs (body weight = 27.35± 0.58 kg) were randomly divided into four groups with 6 lambs in each group. The lambs were fed with the basal diets supplemented with 0 (0 mg/kg group), 500 (500 mg/kg group), 1000 (1000 mg/kg group) and 1500 mg (1500 mg/kg group) GAA per kg diet (DM basis), respectively. The results showed that, as the GAA content of the diet increased, there was a quadratic change in DMI, with the lowest in the 500 mg/kg group and the highest in the 0 mg/kg group. The CK enzyme activity and ATP content in quadriceps muscle increased linearly with increasing levels of diary GAA in the diet. PCr levels and ADP levels in the longest dorsal muscle increased linearly with increasing levels of GAA in the diet. The relative expression of SLC6A6 and SLC6A8 mRNA in the jejunum and ileum mucosa showed a quadratic change as the dietary GAA level increased, with the lowest relative expression in both the 1500 mg/kg group. With the increase of dietary GAA level, both Cr concentration in hepatic vein plasma and the portal plasma GAA concentration shows a quadratic change, with the highest concentration in the 500 mg/kg group and the lowest concentration in the 0 mg/kg group. Therefore, dietary supplementation with 500~1000 mg/kg DM GAA is recommended for lambs.

Haemonchus contortus Infection Alters Gastrointestinal Microbial Community Composition, Protein Digestion and Amino Acid Allocations in Lambs.

The objective of this study was to investigate associations between gastrointestinal microbiota and protein metabolism of lambs infected with Haemonchus contortus. Sixteen male Ujumqin lambs (initial body weight = 32.4 ± 3.9 kg) were dewormed and randomly assigned to 2 equal groups, to be infected or not infected with Haemonchus contortus (GIN and CON, respectively). The experiment lasted 77 days. The GIN lambs had lower packed cell volume (PCV) and increased wormegg count (WEC) after 14 days. Furthermore, in infected lambs, there were decreases in apparent digestibility of dry matter (P = 0.011), crude protein (P = 0.004) and ether extract (P = 0.007), as well as decreased ruminal pepsin (P < 0.001) and lipase (P = 0.032) activity but increased ruminal α-amylase (P = 0.004) and cellulase activity (P = 0.002), and decreased jejunal α-amylase activity (P = 0.033). In addition, infection with H. contortus decreased alpha diversity of the gastrointestinal microbial community in the rumen, abomasum and duodenum, although microbiota associated with carbohydrate and proteolytic metabolism were increased and up to 32 KEGG pathways in the duodenum were predicted to be significantly affected. In conclusion, H. contortus infection in lambs altered the gastrointestinal microbial community composition and disturbed protein digestion and allocation of absorbed amino acids. These results provided insights into consequences of H. contortus infection in lambs and could facilitate development of novel nutritional strategies to improve animal health.

Dietary rumen-protected choline supplementation regulates blood biochemical profiles and urinary metabolome and improves growth performance of growing lambs

This study aimed to assess the growth performance and blood metabolites, as well as metabolic profiles in the urine of lambs fed on dietary rumen-protected choline (RPC). Thirty-six Dorper × Hu lambs weighing approximately 20 kg were equally assigned to three groups, and fed on three diets supplemented with different RPC concentrations (0, 0.25% and 0.75%) for 45 days. Supplementation of RPC significantly increased average daily gain (ADG) and decreased feed-to-gain ratio (F/G) of lambs (p < 0.05). Dietary RPC was significantly associated with elevated plasma high-density lipoprotein (HDL) and suppressed low-density lipoprotein (LDL) levels when compared to the control group (p < 0.05). Moreover, concentrations of very-low-density lipoprotein (VLDL) exhibited an increasing trend (p = 0.065), whereas β-hydroxybutyrate (BHBA) levels decreased (p = 0.086) in plasma. Analysis of urine metabolome revealed that RPC supplementation significantly suppressed urinary concentrations of pyruvate (p < 0.05), while increased urinary concentrations of trimethylamine oxide, p-cresol, phenylacetylglycine and hippurate (p < 0.05). These findings suggest that RPC supplementation can promote weight gain, alter plasma lipid metabolism and modify urinary metabolome which is correlated with energy metabolism, lipid metabolism and intestinal microbial metabolism in lambs. In conclusion, based on our findings, we recommend 0.25% RPC as a supplement for growing lambs.

Fatty acid metabolism in lambs supplemented with different condensed and hydrolysable tannin extracts.

Five groups of lambs (n = 9 each) were used to test the effect of plant extracts rich in hydrolysable (HT) or condensed tannin (CT) on animal performance, fatty acid composition of rumen content, liver and meat. The control group (CO) received a concentrate-based diet without tannins supplementation. The other groups received the same diet as the control lambs plus 4% chestnut (CH) and tara (TA) extracts as a source of HT and mimosa (MI) and gambier (GA) extracts as a source of CT. One-way ANOVA was used to assess the overall effect of dietary treatments, tannins supplementation (CO vs. CH+TA+MI+GA) and the effect of tannin type (HT vs. CT: CH+TA vs. MI+GA) on animal performance, rumen content, liver and intramuscular FA. Dietary CH negatively affected animal performance. The rumen content of the different groups showed similar levels of 18:3 c9c12c15, 18:2 c9c12, 18:2 c9t11, 18:1 t11 and 18:0, whereas 18:1 t10 was greater in CO. Also, 18:1 t10 tended to be lower in the rumen of HT than CT-fed lambs. These data were partially confirmed in liver and meat, where CO showed a greater percentage of individual trans 18:1 fatty acids in comparison with tannins-fed groups. Our findings challenge some accepted generalizations on the use of tannins in ruminant diets as they were ineffective to favour the accumulation of dietary PUFA or healthy fatty acids of biohydrogenation origin in the rumen content and lamb meat, but suggest a generalized influence on BH rather than on specific steps.

Maternofetal inflammation induced for 2 wk in late gestation reduced birth weight and impaired neonatal growth and skeletal muscle glucose metabolism in lambs.

Intrauterine stress impairs growth and metabolism in the fetus and offspring. We recently found that sustained maternofetal inflammation resulted in intrauterine growth-restricted (MI-IUGR) fetuses with asymmetric body composition, impaired muscle glucose metabolism, and β-cell dysfunction near term. These fetuses also exhibited heightened inflammatory tone, which we postulated was a fetal programming mechanism for the IUGR phenotype. Thus, the objective of this study was to determine whether poor growth and metabolism persisted in MI-IUGR lambs after birth. Polypay ewes received serial lipopolysaccharide or saline injections in the first 2 wk of the third trimester of pregnancy to produce MI-IUGR (n = 13) and control (n = 12) lambs, respectively. Lambs were catheterized at 25 d of age. β-Cell function was assessed at 29 d, hindlimb glucose metabolism at 30 d, and daily blood parameters from day 26 to 31. Glucose metabolism was also assessed in flexor digitorum superficialis (FDS) muscle isolated at necropsy on day 31. Asymmetric body composition persisted in MI-IUGR neonates, as these lambs were lighter (P < 0.05) than controls at birth and 31 d, but body and cannon bone lengths did not differ at either age. FDS muscles from MI-IUGR lambs were smaller (P < 0.05) and exhibited reduced (P < 0.05) glucose oxidation and Akt phosphorylation but similar glucose uptake compared with controls when incubated in basal or insulin-spiked media. Similarly, hindlimb glucose oxidation was reduced (P < 0.05) in MI-IUGR lambs under basal and hyperinsulinemic conditions, but hindlimb glucose utilization did not differ from controls. Circulating urea nitrogen and cholesterol were reduced (P < 0.05), and triglycerides, high-density lipoprotein cholesterol, and glucose-to-insulin ratios were increased (P < 0.05) in MI-IUGR lambs. Glucose and insulin concentrations did not differ between groups during basal or hyperglycemic conditions. Although circulating monocyte and granulocyte concentrations were greater (P < 0.05) in MI-IUGR lambs, plasma tumor necrosis factor α (TNFα) was reduced (P < 0.05). FDS muscle contained greater (P < 0.05) TNF receptor 1 (TNFR1) and IκBα protein content. These findings indicate that maternofetal inflammation in late pregnancy results in fetal programming that impairs growth capacity, muscle glucose oxidation, and lipid homeostasis in offspring. Inflammatory indicators measured in this study appear to reflect heightened cytokine sensitivity in muscle and compensatory systemic responses to it.

Fatty acid metabolism in lambs fed hazelnut skin as a partial replacer of maize

The aim of this study was to investigate the effect of dietary inclusion of hazelnut skin (HS) on growth performances and fatty acid metabolism of lambs. Twenty-two lambs were assigned to 2 treatments and fed ad libitum for 56 days: a maize-barley based diet (CON group) or a diet containing 150 g/kg on a dry matter (DM) basis of HS to replace maize (HS group). After slaughter, samples of muscle, rumen and abomasum digesta were collected and analyzed for fatty acid composition. The dietary inclusion of HS did not affect the DM intake, final body weight, carcass weight and average daily gain (P > 0.05), whereas feed conversion ratio was increased by HS diet (P = 0.014). Ruminal fluid pH, ammonia and total volatile fatty acids were not affected by the dietary inclusion of HS (P > 0.05), while HS diet increased the molar proportion of butyrate and reduced the proportion of valerate (P < 0.05). Replacing 150 g/kg dry matter maize with HS increased the concentration of vaccenic acid in ruminal digesta, abomasum content and intramuscular fat (P < 0.01). Polyunsaturated fatty acids (PUFA) of muscle were increased by hazelnut diet (P < 0.05). Although PUFA n-6/n-3 ratio was lower in the control treatment (P < 0.001), atherogenic and thrombogenic indexes were not affected by dietary treatment (P> 0.1). In conclusion, these results suggest that HS could replace 150 g/kg DM of maize without affecting animal performances and increasing the muscle concentration of PUFA and vaccenic acid.

Iron supplementation for lambs experimentally infected by Haemonchus contortus: response to anemia and iron store in the bone marrow

ABSTRACT: To evaluate the effect of supplementation of iron dextran on blood variables and iron metabolism in lambs experimentally infected by Haemonchus contortus, four experimental groups were used: uninfected and non-supplemented animals (GI); infected animals supplemented with iron (GII); uninfected animals supplemented with iron (GIII); and infected non-supplemented animals (GIV). Groups II and IV received 10,000 larvae (L3) of Haemonchus contortus, and groups II and III received three doses of iron dextran (20mg/kg) intramuscularly with seven days of interval. Blood and faeces samples were collected on days 10 (D10), 17 (D17), 24 (D24), and 31 (D31), in order to determine red blood cell counts, iron metabolism, and EPG. Infected animals developed anemia from D24 and anemia was more severe on D31. Animals from GII had higher hematocrit and hemoglobin concentration compared to animals of GIV on D31. Iron stores in the bone marrow were higher in GII and GIII compared to GI and GIV. The GIV showed lower seric levels of iron on D24 compared to the other groups. The iron supplementation reduces the severity of the anemia caused by infection with Haemonchus contortus in lambs, improving erythropoietic response after blood loss.

Phosphorus kinetics in lambs experimentally infected with Trichostrongylus colubriformis with the use of 32P

This study was conducted to evaluate the metabolism and phosphorus (P) kinetics in lambs experimentally infected with Trichostrongylus colubriformis using the isotope dilution technique and modelling. Fifteen male lambs (21.1 ± 1.50 kg) of the Santa Inês hair breed of approximately six months old, distributed in the treatments infected (I, n = 8) and control (C, n = 7) were used. The infected lambs received serial infections with 5000 T. colubriformis larvae, three times per week, for 3 weeks (45 000 T. colubriformis total larvae). After 66 days of the last inoculation of infective larvae, 6.6 MBq of 32P were injected in each lamb to evaluate the P kinetics. Blood, faeces and urine samples were collected in the following seven days and the slaughter of lambs were carried out on the last day in order to collect bone and soft tissues (Liver, kidney, heart and muscle) samples. To analyse P flows, the biomathematical model with four compartments (C1 - gastrointestinal tract, C2 - plasma, C3 - bone and C4 - soft tissue) was used. Similar P intake (VI) between treatments (C and I) was verified. Lower absorption of endogenous (Vaf) and dietary P (Vaa), as well as, lower amount of endogenous P (from saliva) that reaches the gastrointestinal tract (VIT), consequently, higher excretion of dietary P (VFD) were verified in infected lambs (P < 0.1). Additionally, in infected lambs, the P bioavailability was lower compared to control lambs. With the lower absorption (VaT) of P in infected lambs, there was, consequently, lower distribution to bones and soft tissues (VeD2) and lower P deposition in the bones (VO+D). It was concluded that P metabolism of lambs infected with T. colubriformis was altered, with reduced intestinal absorption and bioavailability, increased faecal loss and reduced P flow to the bone.

Effect of pearl millet silage ammoniated with urea on lamb production and metabolic performance

AbstractThe objective of this study was to determine the effect of diets containing pearl millet silage ammoniated with urea on the intake, digestibility, production performance, and nitrogen metabolism of lambs. Thirty‐two uncastrated mixed‐breed lambs at 4 to 5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight replicates. Experimental diets consisted of pearl millet silage ammoniated with urea during ensiling at the levels of 0, 20, 40, and 60 g/kg dry matter (DM). Increasing urea levels in the pearl millet silage led to a linear decrease (p &lt; .05) in the intakes of DM, organic matter, and total digestible nutrients by the lambs. Total and average daily weight gains decreased linearly (p &lt; .05) with the addition of urea to the silage. Intake and digestibility of crude protein, nitrogen intake, urine urea nitrogen, plasma urea nitrogen, microbial synthesis, and microbial efficiency had a quadratic response (p &lt; .05) to the urea levels in the silage. Pearl millet silage ammoniated with urea reduces dry‐matter intake and daily weight gain in lambs. Urea is not recommended for use in the ensiling of pearl millet.

Effects of early experience with low-quality roughage on liver metabolome in lambs

Early experience with low-quality roughage has the potential to improve its utilization in ruminants. This study determined the effects of early experience with low-quality roughage on dry matter intake (DMI), body weight (BW) and the hepatic metabolism of lambs. Ten lambs (3 month old) were randomly allocated to two treatments: the low-quality roughage group (LR) or the control group (C). The study lasted 7 months. In the first 4 months, LR was fed low-quality roughage, whereas C was fed normal roughage. In the last 3 months, both groups were fed low-quality roughage. Dry matter intake (DMI) was determined at the 1st, 3rd, 5th and 7th months (P1, P2, P3 and P4). Analysis of liver tissue metabolomics were carried out in P2 and P3. DMI was greater in LR than C in P1 (p < 0.05), but did not differ in P2. In P3 and P4, DMI was greater in LR than in C (p < 0.01). The concentration of five glycolysis/gluconeogenesis intermediates, some lipid metabolism-related metabolites, six amino acids and several amino acid metabolism-related metabolites were different between treatments in P2. From P2 to P3, concentrations of these metabolites changed in LR. However, no difference was found between treatments in P3. Feeding low-quality roughage to lambs early in life influenced hepatic glycolysis/gluconeogenesis, fatty acid oxidation and amino acid metabolism. However, for lambs who had no early experience with low-quality roughage, similar alterations were induced in the liver after 1 month of eating low-quality roughage.

356 The effects of supplementing eicosapentaenoic acid and docosahenaenoic acid during late gestation on lamb metabolism and performance

356 The effects of supplementing eicosapentaenoic acid and docosahenaenoic acid during late gestation on lamb metabolism and performance