The objective of this study was to evaluate the fermentative characteristics and chemical composition of cochineal nopal cactus silage additives with urea or Lactobacillus buchneri (LB), as well as the association of both additives in four storage times (7, 15, 60 and 120 days) and during aerobic stability, with evaluations at 0, 48 and 96 h. Four silages were used: no additive, addition of 2% urea, addition of LB and addition of 2% urea and LB. The study was divided into two experiments: the first experiment evaluated the silages at different storage times, and the second experiment evaluated the silages during the aerobic stability test. In both experiments, the experimental design was completely randomized in a factorial scheme (4 × 4 and 4 × 3) with three replicates per treatment. After the ensiling process, lactic acid bacteria predominated in all treatments. The concentration of lactic acid increased significantly from 60 days of ensiling. The concentration of acetic acid varied significantly between the storage times only for the silages treated with urea and LB alone. The silage treated with urea maintained a constant pH value up to 120 days of storage. During the 96 h aerobic stability test, no breaking in the stability of silages was observed. The exclusive or associated use of urea and LB promotes improvement in the fermentative characteristics of cochineal nopal cactus silage, without major alterations in the chemical composition or interfering with the aerobic stability of the silages.

The aim of this study was to investigate the effects of Cactus (Opuntia spp) levels in total mixed ration silages based on Cactus and Gliricidia (Gliricidia sepium (Jacq.) Steud) on the fermentation profile, microbial populations, aerobic stability and taxonomic diversity. The completely randomized design was used in a 4 × 4 factorial design with four replications, being four rations with different levels of Cactus (15, 30, 45, 60% based on the dry matter) and four opening periods (0, 15, 30 and 60 days of fermentation). An interaction effect (P < 0.050) was observed among the diets and opening times for mould and yeast populations. An interaction effect for the levels of acetic acid was observed, where the diets 15, 30, 45 and 60% showed higher values at 60 days (0.44, 0.41, 0.35 and 0.40 g/kg DM, respectively). A significant difference was observed for the richness and diversity index (Chao1 and Shannon). The most abundant bacterial phyla were Proteobacteria and Firmicutes and the genera Lactobacillus and Weissella. Cactus can be added in total mixed ration silages up to the level of 60% in a way that it positively affects the qualitative indicators of the silages, modulating the taxonomic communities and allowing the predominance of important groups for preservation of the ensiled mass.

To investigate the cumulative effects of maternal supplementation with nucleotides in the form of uridine (UR) on fatty acid and amino acid constituents of neonatal piglets, fifty-two sows in late gestation were assigned randomly into the control (CON) group (fed a basal diet) or UR group (fed a basal diet with 150 g/t UR). Samples of neonates were collected during farrowing. Results showed that supplementing with UR in sows’ diet significantly decreased the birth mortality of pigs (P = 0·05), and increased serum total cholesterol, HDL and LDL of neonatal piglets (P < 0·05). Moreover, the amino acid profile of serum and liver of neonatal piglets was affected by the addition of UR in sows’ diets (P < 0·05). Furthermore, an up-regulation of mRNA expression of energy metabolism-related genes, including fatty acid elongase 5, fatty acid desaturase 1, hormone-sensitive lipase and cholesterol-7a-hydroxylase, was observed in the liver of neonates from the UR group. Additionally, a decrease in placental gene expression of excitatory amino acid transporters 2, excitatory amino acid transporter 3 and neutral AA transporter 1 in the UR group was concurrently observed (P < 0·05), and higher protein expression of phosphorylated protein kinase B, raptor, PPARα and PPARγ in placenta from the UR group was also observed (P < 0·05). Together, these results showed that maternal UR supplementation could regulate placental nutrient transport, largely in response to an alteration of mTORC1–PPAR signalling, thus regulating the nutrition metabolism of neonatal piglets and improving reproductive performance.

This study investigated the effect of pre-exercise α-lactalbumin ingestion on subsequent endurance exercise performance, muscle pain and mood states. In a two-stage cross-over counterbalance design, eleven male endurance runners (age: 31 (se 2) years, height: 169·5 (se 4·4) cm, weight: 63·6 (se 5·1) kg, V̇O2max: 58·8 (se 6·3) ml/kg per min) consumed two solutions (carbohydrate+α-lactalbumin, CA; carbohydrate+whey protein isolate, CW) 2 h before a self-paced 21-km run. Creatine kinase, IL-6, muscle pain, pressure pain threshold (PPT) and mood states were assessed 2 h before exercise, immediately before exercise (Pre-ex0) and immediately after exercise (Post-ex0). No difference was found in 21-km running performance between two trials (CA v. CW: 115·85 (se 5·20) v. 118·85 (se 5·51) min, P=0·48). Compared with CW, CA led to higher PPT at Pre-ex0 (41·77 (se 2·27) v. 35·56 (se 2·10) N/cm2, P<0·01) and Post-ex0 (38·76 (se 3·23) v. 35·30 (se 3·55) N/cm2, P=0·047). Compared with CW, CA reduced the feeling of fatigue at Post-ex0 (P<0·01); CA also reduced salivary cortisol levels at Post-ex0 (0·72 (se 0·07) v. 0·83 (se 0·13) ng/ml, P<0·01). In conclusion, the ingestion of α-lactalbumin did not improve the 21-km time-trial performance. However, compared with the pre-exercise ingestion of whey protein, that of α-lactalbumin led to superior results during similar levels of endurance exercise: it elevated PPT and reduced the feeling of fatigue and the cortisol levels.

Selected fatty acids, such as pelargonic acid and caprylic acid, are effective nonselective herbicides for a wide spectrum of annual weed species. Greenhouse and field studies evaluated the potential of certain food-grade organic acids to enhance herbicide activity of pelargonic acid-based formulations. The addition of diammonium succinate and succinic acid improved the efficacy of a pelargonic acid formulation from 117 to 200% in the greenhouse. L-Lactic acid and glycolic acid enhanced the efficacy of pelargonic acid formulations on velvetleaf and common lambsquarters in the greenhouse by 126 to 168% and in the field by 117 to 138%. Thus, combinations of fatty and organic acids with selected emulsifiers can be highly effective as safe, nonselective herbicides.

Physical properties of lactose appeared influenced by presence of lactic acid in the system. Some other components such as Ca may further attenuate lactose behaviour and impact its phase transition. A model-based study was thus implemented with varying concentrations of Ca (0·12, 0·072 or 0·035% w/w) and lactic acid (0·05, 0·2, 0·4 or 1% w/w) in establishing the effects of these two main acid whey constituents on lactose phase behaviour. Concentrated solutions (50% w/w) containing lactose, lactic acid and Ca were analysed for thermal behaviour and structural changes by Differential Scanning Colorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. Presence of 1% (w/w) lactic acid and 0·12% (w/w) Ca in lactose solution significantly increased the evaporation enthalpy of water, delayed and increased the energy required for lactose crystallisation as compared to pure lactose. FTIR analysis indicated a strong hydration layer surrounding lactose molecules, restricting water mobility and/or inducing structural changes of lactose, hindering its crystallisation. The formation of calcium lactate, which restricts the diffusion of lactose molecules, is also partly responsible. It appears that Ca removal from acid whey may be a necessary step in improving the processability of acid whey.

Six ruminal cannulated Texel sheep were used to assess the dose response and the effect of live yeasts (Levucell® SC, Saccharomyces cerevisiae CNCM I-1077) on the prevention of induced ruminal latent acidosis. The sheep received, in a replicated 3×3 Latin-square design, an acidotic diet (wheat +lucerne hay, 60:40 (dry matter (DM) basis); starch: 410 g/kg DM) without yeast (control group; L0 treatment), supplemented with 0·2 g/day yeast (4×109 colony-forming units (c.f.u.) per day corresponding to producer recommendations; L1 treatment) or with 2 g/day yeast (4×1010 c.f.u. per day; L10 treatment). The following measurements were carried out: food intake, ruminal pH, ruminal volatile fatty acids (VFA), lactate and ammonia (NH3) concentrations, protozoal and lactate-utilizing bacterial counts, relative proportions of two main bacteria implicated in lactate metabolism (a lactate-producing species, Streptococcus bovis, and a lactate-utilizing species, Megasphaera elsdenii) using specific 16S-rRNA-targeting oligonucleotide probes, activities of lactate dehydrogenase (LDH) and of polysaccharidases involved in plant cell wall (xylanase, carboxymethylcellulase) and starch (amylase) degradation. The acidotic diet (L0) induced a butyric (12 mol per 100 mol total VFA) rather than lactic (<4 mmol/l) ruminal latent acidosis. Ruminal pH, fermentative patterns, lactate-metabolizing bacteria (concentration, LDH activity) and polysaccharidase activities were similar between treatments (P>0·1). Yeast supplementation tended to increase ruminal protozoal population (P<0·1) and intake of animals (P<0·1). The recommended yeast concentration (L1) was sufficient to ensure these effects. The yeast's action may differ according to the nature and function of the micro-organisms involved and the type of fermentative pattern favoured (protozoa/butyrate v. lactate-metabolizing bacteria/lactate and propionate) during ruminal acidosis in sheep.

Two experiments were conducted to investigate the use of dietary manipulation as a means of improving piglet post-weaning performance and gastro-intestinal health. In experiment 1, 144 piglets (24 days old) in a 3 × 2 factorial arrangement were offered diets containing 65, 170 and 280 g lactose per kg with or without lactic acid (16 g/kg) for 28 days. In experiment 2, 20 piglets (24 days old) (in a 2 × 2 factorial arrangement were offered the following diets for 7 days and then sacrificed: T1) basal diet; T2) basal diet + 15 g inulin per kg; T3) basal diet + 16 g lactic acid per kg and T4) basal diet + 15 g inulin per kg + 16 g lactic acid per kg. After slaughtering, tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the ileum, caecum and colon for microbiology and volatile fatty acid analysis. In experiment 1, pigs offered diets containing lactic acid had improved daily gain (P < 0·01) and food efficiency (P < 0·05) from days 0 to 7 compared with pigs offered diets containing no lactic acid. There was a linear increase (P < 0·05) in average daily gain (ADG) from days 0 to 28 and a linear decrease in faecal pH (P < 0·01) with increasing lactose levels. There was a quadratic effect of lactose on food conversion ratio from days 0 to 28 (P < 0·05). In experiment 2, there was a significant interaction between inulin and lactic acid in villous height in the jejunum (P < 0·001) and the concentrations of lactobacilli (P < 0·1) and E. coli (P < 0·05) in the colon. The inclusion of inulin and lactic acid resulted in a significant increase in villous height compared with the inulin only diet (P < 0·001). However, lactic acid had no effect on villous height in pigs offered diets without inulin supplementation. The inclusion of lactic acid and inulin caused a significant increase in both lactobacilli and E. coli concentrations compared with the inulin only diets (P < 0·05). However, neither inulin nor lactic acid had an effect on lactobacilli and E. coli numbers in isolation of the other. In conclusion, in experiment 1, lactic acid improved performance in the 1st week post weaning. There was a linear increase in ADG with increasing lactose levels. In experiment 2, the combination of lactic acid and inulin increased villous height in the jejunum and concentrations of lactobacilli and E. coli in the colon.

Background and objective The purpose of this study was to investigate retrospectively what factors contribute to the development of the type of hyperlactatemia which may follow cardiopulmonary bypass despite well-maintained oxygen delivery and a normal perioperative course.

Methods The medical records of 124 patients undergoing elective cardiac surgery using cardiopulmonary bypass were reviewed. The patients were divided into a hyperlactatemia group (n = 34), where the serum lactate concentration was > 5.0 mmol L−1 perioperatively, and a normal lactatemia group (n=90), which comprised the remaining patients.

Results The duration of cardiopulmonary bypass in the hyperlactatemia group was significantly longer than for the normal lactatemia group. Significant differences of lactate concentrations between the groups, and significant elevations of serum lactate had been observed after the start of cardiopulmonary bypass. Oxygen extraction rates were significantly reduced during the period of cardiopulmonary bypass but, on the contrary, increased in the hyperlactatemia group after surgery. The area under the curve of mean arterial pressure consisted of 5-min interval plots during the initial period of cardiopulmonary bypass in the hyperlactatemia group. This was significantly smaller than for the normal lactatemia group. Weakly significant correlations between maximal lactate and duration of cardiopulmonary bypass, and especially the area under the curve, were observed.

Conclusions It is suggested that the pathophysiology observed is based on impairment of tissue oxygen utilization. The duration of cardiopulmonary bypass and especially the occurrence of hypotension at the start of the bypass period appears to be related to the development of lactic acidosis.

The main purpose of this study was to quantify the absorption of nutrients derived from carbohydrate assimilation in a model experiment with catheterised pigs. A low-fibre (LF) diet based on wheat flour and two high-fibre diets with added insoluble fibre from wheat bran (HFWB) or soluble fibre from oat bran (HFOB) were used. The diets were offered as baked rolls to three catheterised pigs in a 3×3 Latin square design. The pigs were surgically fitted with catheters placed in the portal vein and mesenteric artery and with an ultrasonic flow probe attached to the portal vein to monitor the blood-flow rate. The pigs were fed the diets three times daily and portal and arterial blood samples collected twice weekly up to 8 h after the morning feeding. Glucose, insulin, lactic acid (LA) and short-chain fatty acids (SCFA) were determined on the samples. The baseline level of glucose in the portal vein was about 6 mmol/l increasing to 10–11 mmol/l 20–30 min post-feeding with no difference among the different diets. Portal and arterial insulin mirrored portal glucose concentration and was also unaffected by the dietary composition. The net absorption of glucose (per 24 h) was: diet LF 4190 mmol; diet HFWB 3050 mmol and diet HFOB 3190 mmol corresponding to a recovery of 0·76–0·92 of ingested starch. The levels of LA and SCFA in the portal vein were relatively constant in the postprandial period. The net absorption of LA and SCFA was in the same order (749 and 720 mmol/d respectively) with diet LF, while LA was lower (384 and 582 mmol/d) and SCFA higher (738 to 891 mmol/d) when feeding the two high-fibre diets. There was a higher molar proportion of butyrate in the portal vein after feeding the high-fibre diet supplemented with oat bran as compared with the wheat-based diets.

Sixteen first lactation dairy cows were used in a 2 × 2 × 2 × 2 factorial design experiment. Two silages, an extensively fermented inoculant-treated silage or a restricted fermented, mixed aliphatic carboxylic acid-treated silage were offered with two concentrate types (starch- or fibre-based) and supplementary lactic acid (LA, 0·4 kg/day) or soya oil (SO, 0·41 kg/day). Concentrates containing 180 g crude protein per kg were offered at 6 kg/day. Silage dry-matter intake tended to be higher (P = 0·07) with restricted fermented silage compared with the inoculant silage. Milk fat or protein concentrations were not significantly affected (P > 0·05) by silage fermentation type. LA inclusion had no significant effect (P > 0·05) on animal performance. SO inclusion significantly increased (P < 0-05) milk yield (+ 0·8 kg/day), decreased milk fat concentration and yield (40·2, 32·9 g/kg and 779, 667 g/dayfor - and + SO respectively, P< 0·001) and decreased milk protein concentration (-0·81 g/kg, P < 0·01). A significant concentrate × soya-oil interaction (P<0·01) suggested a greater reduction in milk fat concentration with the SO, starch compared with the SO, fibre combination. Modified acid-detergent fibre (P < 0·01) and neutraldetergent fibre (P < 0·001) apparent digestibility coefficients were significantly lower with starch- compared with fibre-based concentrates. Results suggest that milk production responses to changes in concentrate composition were not influenced by the extent of restriction of the silage fermentation process.