Nicotinic acid increases adiponectin secretion from differentiated bovine preadipocytes through G-protein coupled receptor signaling.

The transition period in dairy cows (3 weeks prepartum until 3 weeks postpartum) is associated with substantial mobilization of energy stores, which is often associated with metabolic diseases. Nicotinic acid (NA) is an antilipolytic and lipid-lowering compound used to treat dyslipidaemia in humans, and it also reduces non-esterified fatty acids in cattle. In mice the G-protein coupled receptor 109A (GPR109A) ligand NA positively affects the secretion of adiponectin, an important modulator of glucose and fat metabolism. In cattle, the corresponding data linking NA to adiponectin are missing. Our objective was to examine the effects of NA on adiponectin and AMPK protein abundance and the expression of mRNAs of related genes such as chemerin, an adipokine that enhances adiponectin secretion in vitro. Differentiated bovine adipocytes were incubated with pertussis toxin (PTX) to verify the involvement of GPR signaling, and treated with 10 or 15 µM NA for 12 or 24 h. NA increased adiponectin concentrations (p ≤ 0.001) and the mRNA abundances of GPR109A (p ≤ 0.05) and chemerin (p ≤ 0.01). Pre-incubation with PTX reduced the adiponectin response to NA (p ≤ 0.001). The NA-stimulated secretion of adiponectin and the mRNA expression of chemerin in the bovine adipocytes were suggestive of GPR signaling-dependent improved insulin sensitivity and/or adipocyte metabolism in dairy cows.

Investigating the effect of supplementing different levels of Isochrysis galbana on in vitro rumen fermentation parameters.

This study aimed to investigate the effect of supplementing Isochrysis galbana (I. galbana) at levels of 0 (control), 1, 2, 3, 4, and 5 (g/100 g DM) of the diet on the gas production kinetics, methane production, rumen fermentation parameters, and relative microbial population in vitro. Supplementation of I. galbana at high level (5 g/100 g DM) caused a significant decrease in total gas production (p < 0.05). High supplementation rates (4 and 5 g/100 g DM) decreased CH4 production relative to the control by 18.4% and 23.2%, respectively. Although rumen ammonia nitrogen (N-NH3) and total volatile fatty acids (VFA) concentrations were affected by dietary treatments, but the VFA profile did not changed. The relative proportion of protozoa and methanogenic archaea as well as Anaerovibrio lipolytica, Prevotella spp., Ruminococcus flavefaciens, and Fibrobacter succinogenes were decreased significantly as a result of microalgae supplementation. However, the relative abundance of Ruminococcus albus, Butyrivibrio fibrisolvens and Selenomonas ruminantium were significantly increased (p < 0.05), related to the control group. As well, the pH was not affected by dietary treatments. It was concluded that I. galbana reduced in vitro CH4 production and methanogenic archaea that its worth to be investigated further in in vivo studies.

Effect of Lactobacillus sp. and yeast supplementation on performance and some blood attributes in deoxynivalenol-challenged broiler chickens.

An experiment was conducted to evaluate the effect of different concentrations of probiotic (Lactobacillus sp.) and yeast (Saccharomycese cerevisiae) on performance, organ attributes and blood traits in broiler chickens. A total of 360 one-day-old female broiler chickens (Hubbard)® were allocated to 9 treatments and four replicates (10 birds per replication). The trail was performed in a completely randomized design (3 × 3 factorial arrangement) to examine the interaction effect of three concentrations of Lactobacillus sp. (0, 0.2 and 0.4 g/kg) and yeast (0, 0.75 and 1.5 g/kg) in deoxynivalenol (DON)-contaminated diets. The results showed that consumption of Lactobacillus sp. and yeast in DON-contaminated diets did not have a significant effect on broiler performance except for feed intake during starter period which was enhanced by yeast administration (P < 0.05). Increasing the Lactobacillus sp. content also reduced (P = 0.05) the proportional liver weight. Administration of Lactobacillus sp. to DON diets increased total protein, albumin and globulin concentrations (P < 0.05). Calcium and creatinine were influenced by yeast and Lactobacillus sp., respectively. Yeast (1.5 g/kg) and Lactobacillus sp. (0.2 g/kg) and combination of two additives (1.5 × 0.2) led to lower triglyceride concentration compared to DON group (P < 0.05). The DON diet increased aspartate amino transferase (AST) and lactate dehydrogenase (LDH) enzymes concentrations; while, inclusion of 0.4 g/kg Lactobacillus sp. to DON diet decreased AST and LDH enzymes concentrations (P < 0.05). In conclusion, administration of Lactobacillus sp. and yeast could not influence the performance of DON-fed birds; but these additives could reduce negative effects of DON on enzyme activities and some blood attributes.

Effects of Soybean and Linseed Oils Calcium Salts and Starter Protein Content on Growth Performance, Immune Response, and Nitrogen Utilization Efficiency in Holstein Dairy Calves.

This study aimed to investigate the interaction of fatty acid (FA) source [calcium salt of soybean oil (n-6 FA) vs. calcium salt of linseed oil (n-3 FA) both 3% DM basis] with protein content (18% vs. 22% CP, based on DM) on growth performance, blood metabolites, immune function, skeletal growth indices, urinary purine derivatives (PD), and microbial protein synthesis (MPS) in young dairy calves. Forty 3-day-old calves (20 females and 20 males) with a starting body weight (BW) of 40.2 kg were assigned in a completely randomized block design in a 2 × 2 factorial arrangement of treatments. Experimental diets were: (1) n-6 FA with 18% CP (n-6-18CP), (2) n-6 FA with 22% CP (n-6-22CP), (3) n-3 FA with 18% CP (n-3-18CP), and (4) n-3 FA with 22% CP (n-3-22CP). Starter feed intake and average daily gain (ADG) were not influenced by experimental diets (p > 0.05). However, before weaning and the entire period, feed efficiency (FE) was greater in calves fed n-3 FA compared to n-6 FA (p < 0.05). Heart girth (weaning, p < 0.05) and hip height (weaning, p < 0.05 and final, p < 0.01) were highest among experimental treatments in calves who received n-3-22CP diets. The greatest blood glucose (p < 0.05) and insulin (p < 0.01) concentrations in the pre-weaning period and the lowest serum concentration of tumor necrosis factor (before weaning, p < 0.05) were observed in calves fed the n-3-22CP diet. However, the greatest blood urea N (before weaning, p < 0.05; after weaning, p < 0.05) and urinary N excretion (p < 0.05) were found in calves fed n-6-22CP diets compared to other experimental arrangements. In conclusion, offering calves with Ca-salt of n-3 FA along with 22% CP content may be related to improved nitrogen efficiency and immune function.

Effects of feed restriction and supplementary garlic oil on blood metabolites in ewes.

The effects of garlic oil (GO) on serum fatty acids, lipid profiles and energy-related blood metabolites in feed-restricted fat-tailed ewes were investigated. For this purpose, twenty-eight dry, non-pregnant Makuei ewes (about three years of age; 45.00 ± 2.20 kg of body weight) were assigned randomly to four experimental groups including group 1 receiving basal diet as total mixed ration (TMR) without GO supplementation (control group), group 2 receiving 100% basal diet supplemented with GO (10.00 mg kg-1 BW), group 3 receiving 70.00% basal diet without GO supplementation and group 4 receiving 70.00% basal diet supplemented with GO (10.00 mg kg-1 BW). The main experimental period started eight weeks after performing adaptation and dietary allocations. Feed restriction reduced serum glucose levels along with higher serum levels of non-esterified fatty acids, triacylglycerols, ß-hydroxybutyrate, low-density lipoprotein cholesterol, total cholesterol and very low-density of lipoprotein. Following feed restriction, the serum palmitic and oleic acids concentrations were increased. Garlic oil supplementation had a desirable effect on feed-restricted animals through lowering serum BHB and palmitic and oleic acids concentration and increasing the high-density lipoprotein cholesterol levels in the serum. These findings demonstrated that GO had the potential to reduce body-fat mobilization, thereby lowering the risk factors for disorders associated with negative energy balance in underfed ewes in the periparturient period.

Investigating the effects of varying wall materials and oil loading levels on stability and nutritional values of spray dried fish oil.

High oxidative capacity of polyunsaturated fatty acid rich oils is the main problem with their dietary application. The main objectives of this study were to determine the effects of different encapsulants and oil loading levels on nutritive value, fatty acid profile, and oxidative stability of microencapsulated fish oil powders. Four types of wall materials [glucose syrup and maltodextrin based Maillard reaction products (MRP) or equivalent non-reacted physical blends (Non-MRP)] were used along with the three levels of oil loadings (oil to wall ratio of 1:2; 1:1; 2:1 as low, medium and high oil loadings). Emulsions and resulting microencapsules were tested for fatty acid content and stability if fatty acids over time. Additionally, different oxidative parameters were used to assess the oxidative stability of the microencapsules. Results showed that high oil loading significantly increased the mean particle size of emulsions and resultant powders and concomitantly reduced microencapsulation efficiency (ME) and yield of capsules in all of the tested wall materials. However, MRP exhibited better performance. Maillard reaction products showed better protection efficiency against oil oxidation relative to non-MRP. Nevertheless, two types of MRP encapsulants showed different proficiency and glucose syrup-MRP, provided more protection than Maltodextrin-MRP. Maillard reaction had a positive correlation with the stability properties of emulsions and resulting microcapsules. Our results showed that microencapsulation with Maillard reaction products could be used as an efficient way to protect fish oil from oxidation.

Microwave irradiation of whole soybeans in ruminant nutrition: Protein and carbohydrate metabolism in vitro and in situ.

Whole soybeans serve as one of the main sources of protein in ruminant nutrition. Different processing methods have been employed for ruminal protein protection. The present study was conducted to determine the effects of microwave irradiation [900 W; 2, 4 and 6 min] on quality, ruminal degradability and estimated in vitro intestinal digestibility of availability soybean crude protein. This experiment was performed in a completely randomized design with seven treatments including control (no processing), along with 2, 4 and 6 min of microwave irradiation on whole and ground soybeans. Protein and carbohydrate fractions were determined according to Cornell Net Carbohydrate and Protein System (CNCPS). Triplicates of the samples were incubated in the rumen of three cannulated Holstein steers for up to 48 hr. Microwave irradiation increased neutral detergent insoluble nitrogen, metabolizable protein content and resulted in a lower effective rumen degradability and in vitro gas production. Nevertheless, longer processing time led to higher unavailable protein and carbohydrate fractions. In the main, microwave irradiation of ground samples for 4 min increased metabolizable protein content, without negative effects on protein and carbohydrate availability.

The potential of sunflower (Helianthus annuus) residues silage as a forage source in Mohabadi dairy goats.

This study was conducted to determine the chemical composition and nutritive value of sunflower residues silage (SRS) and effects of its substitution with alfalfa hay and corn silage on lactation performance, feed intake, nutrient digestibility and some blood parameters of Mohabadi dairy goats. Four experimental diets were formulated to gradually replace alfalfa hay and corn silage with SRS as follows: Control (no inclusion of SRS, group 1) and groups 2 to 4, representing 15, 30 and 45.00% replacement of common forages in the diet with SRS, respectively. Sixteen multiparous dairy goats weighing 60.00 ± 3.00 were divided into two 4 × 4 latin square design. Ensiling was being able to increase crude protein content, reduce neutral detergent fiber and increase acid detergent lignin in sunflower residues. Daily dry matter (DM) intake and DM and organic matter (OM) digestibility decreased with increasing levels of SRS in the diet. The highest and the lowest digestibility coefficients belonged to 30 and 45.00% embedment levels, respectively. Milk yield decreased with increasing levels of SRS and differences were statistically significant compared to the highest substitution level. Milk composition was similar among diets, but daily production of milk decreased in higher substation levels. Statistically significant differences were found in serum low-density lipoproteins (LDL) concentrations between treatments and LDL levels decreased as dietary levels of SRS increased. According to these results, SRS is an acceptable feed for dairy goats and common dietary forages can be replaced up to 30.00% with SRS without negative effects on milk yield and composition.

Indigestible neutral detergent fibers: Relationship between forage fragility and neutral detergent fibers digestibility in total mixed ration and some feedstuffs in dairy cattle.

Indigestible neutral detergent fibers (iNDF) accurately predict forage digestibility when measured in situ. The objective of this study was to determine the effects of rumen incubation times on the estimated concentrations of iNDF for four forages (alfalfa hay, corn silage, wheat straw and orchard grass), four concentrates (barley grain, soybean meal, beet pulp and wheat bran) and two total mixed ration samples in dairy cows. The iNDF contents of the samples were evaluated in 10 feeds using three ruminally cannulated Holstein cows in a completely randomized design. Five grams of the samples were incubated up to 240 hr. The iNDF fraction was significantly affected by incubation time for all of the tested samples, but the potentially digestible NDF fraction (pdNDF) was not affected for wheat straw, barley grain and wheat bran (32.32, 10.11 and 20.60 g per 100 g of dry matter, respectively). For most of concentrates feedstuffs, the iNDF fraction could be measured after 120 hr of incubation, while for forages ruminal incubation should be lasted up to 240 hr. Statistically significant differences (p < 0.01) were observed between forage samples regarding fragility and NDF digestibility (NDFD). Also, a positive correlation was observed between fragility and NDFD. In some of the cases, it appears that NDFD can be a more helpful index in adjusting pdNDF values than direct fragility measurements.