Effect of crude glycerin on feed manufacturing, growth performance, plasma metabolites, and nutrient digestibility of growing-finishing pigs.

Three experiments were conducted to determine the effects of dietary addition of crude glycerin on pellet production efficiency and to evaluate its effect on growth performance and digestibility in growing-finishing pigs. Three dietary treatments were created by addition of 0, 2.5, or 5% crude glycerin to barley-soybean meal-based diet, and 4 batches of each dietary treatment (2 each for grower and finisher diets) were prepared. In the manufacturing process, crude glycerin supplementation linearly increased the feeder speed and production rate (P < 0.05), resulting in a 20 to 29% improvement in the feed production rate compared with the control. Production efficiency (kg/kWh) increased linearly (P < 0.05) as the level of crude glycerin in feed increased. A growth experiment was performed with 240 barrows (30 ± 1 kg initial BW) using a 2-phase feeding program over a 12-wk period with 4 pens per treatment and 20 pigs per pen. On the last day of the growth experiment, blood samples were collected to determine circulating glucose, fructosamine, and IGF-1 concentrations. Overall growth performance was not affected (P > 0.05) by dietary treatment, and there was no effect (P > 0.05) of dietary treatment on any plasma metabolite measured. A digestibility experiment involving 9 male pigs housed in metabolic cages was used to determine the coefficients of apparent fecal digestibility and N and mineral balances. Pigs were assigned to 1 of the 3 diets in each feeding period using a 3 × 3 Latin square arrangement of treatments (43 ± 3 and 74 ± 3 kg initial BW in the growing and finishing periods, respectively). In both feeding periods, fecal digestibility of OM and ether extract were affected by dietary treatment, increasing linearly (P < 0.05) with increasing crude glycerin levels. However, neither CP digestibility nor N retention was affected by the glycerin content in either the growing or finishing period. Digestibilities and balance of Ca and P showed opposite tendencies with the variations in crude glycerin content, which either decreased or increased depending on the feeding period. In conclusion, adding crude glycerin to the diet before pelleting improved feed mill production efficiency. The addition of crude glycerin up to 5% in the diet of growing-finishing pigs had no effect on growth performance, blood metabolites, nutrient digestibility, and N balance, but more studies are needed to determine how crude glycerin affects mineral metabolism and balance.

Effect of aluminum sulfate on litter composition and ammonia emission in a single flock of broilers up to 42 days of age.

New alternatives are necessary if the environmental impact linked to intensive poultry production is to be reduced, and different litter handling methods should be explored. Among these, acidifying amendments added to poultry litters has been suggested as a management practice to help reduce the potential environmental effect involved in multiple flock cycles. There have been several studies on the use of aluminum sulfate (alum) and its benefits, but almost no data are available under farm conditions in Europe. An experiment with Ross 308 broilers from 1 to 42 days of age was conducted to evaluate the effect of alum on litter composition, the solubility of some mineral elements and NH3 emission during a single flock-rearing period in commercial houses located in southeast Spain. Broilers were placed on clean wood shavings in four commercial houses, containing 20 000 broilers each. Before filling, alum was applied at a rate of 0.25 kg/m2 to the wood shavings of two poultry houses, whereas the remaining two were used as control. Litter from each poultry house was sampled every 3 to 5 days. Ammonia emissions from the poultry houses were monitored from 37 to 42 days of age. In comparison with the control group, alum treatment significantly reduced the pH level of the litter (P < 0.001) with an average difference of 1.32 ± 0.24 units. Alum-treated litter showed, on average, a higher electrical conductivity than the control litter (5.52 v. 3.63 dS/m). The dry matter (DM) and total N and P contents did not show differences between the treatments (P > 0.05). Regarding the NH4 +-N content, alum-treated litter showed a higher value than the untreated litter, with an average difference of 0.16 ± 0.07% (on a DM basis). On average, alum-treated litter had lower water-soluble P, Zn and Cu contents than the untreated litter. Alum noticeably reduced the in-house ammonia concentration (P < 0.001), with an average of 4.8 ppm at 42 days of age (62.9% lower than the control), and ammonia emissions from 37 to 42 days of age were significantly reduced by the alum treatment (P < 0.001), representing a reduction of 73.3%. The lower pH values might have reduced ammonia volatilization from the litter, with a corresponding positive effect on the building environment and poultry health. For these reasons, litter amendment with alum could be recommended as a way of reducing the pollution potential of European broiler facilities during a single flock cycle.

Effect of low-protein diets and single sex on production performance, plasma metabolites, digestibility, and nitrogen excretion in 1- to 48-day-old broilers.

Two experiments were conducted to investigate the effect of low-CP diets supplemented with crystalline amino acids, according to an ideal amino acid ratio, on the performance, plasma metabolites, nutrient digestibility, nitrogen balance, and water intake in male and female chickens from 1 to 48 d of age using a 4-phase feeding program: prestarter (1-7 d), starter (8-21 d), grower (22-35 d), and finisher (36-48 d). Three experimental diets were formulated for each phase: a control diet with a CP level of 24.5, 23.0, 21.5, and 20.5%, respectively, and medium- and low-CP diets containing 1.5 and 3% less than that of the control, respectively, but the same ME and digestible lysine levels. In experiment 1, in males, the reduction in dietary protein content by 3% increased the feed conversion ratio (P < 0.05) in the starter, grower, and finisher phases, and plasma albumin levels were reduced (P < 0.05) during the prestarter, starter, and finisher phases. In females, the same effect on plasma album levels was observed (P < 0.05) only in the starter phase. Sex affected plasma albumin levels during the prestarter, starter, and finisher phases, being higher in females. In experiment 2, the reduction in dietary protein content linearly decreased water consumption in both sexes (P < 0.05). The reduction of dietary protein by 1.5 or 3% reduced nitrogen excretion to the environment by 9.5 and 17% in males and by 11.8 and 14.6% in females, respectively. In summary, the low-CP 4-phase feeding reduced water intake and nitrogen excretion with an adverse effect on the feed conversion ratio in males but not in females. So, single-sex rearing could be used to reduce the environmental impact of chicken farms.

Effect of dietary crude protein levels in a commercial range, on the nitrogen balance, ammonia emission and pollutant characteristics of slurry in fattening pigs.

An experiment was conducted to investigate the effect of dietary levels of crude protein (CP), close to the range used commercially and to the European Commission recommended values, on the nitrogen (N) balance, ammonia (NH(3)) emission and pollutant characteristics of the slurry from growing and finishing pigs. Three feeding programmes with different CP levels were compared during the growing and the finishing periods of fattening. Diets were formulated to be isoenergetic and for the digestible lysine : metabolisable energy ratio to be similar in all the diets for each phase, but differed in CP concentration (160, 150 and 140 g CP/kg for the growing phase and 155, 145 and 135 g CP/kg for the finishing phase). Faeces and urine from barrows (eight replicates per diet) allocated in metabolism cages were collected separately for 5 days to calculate the N balance and for 2 days to measure NH(3) emission in a laboratory system for 240 h. Excreta were analysed for pH, volatile fatty acids (VFA), total N, electrical conductivity (EC), total solids (TS), volatile solids (VS), biochemical oxygen demand (BOD(5)), chemical oxygen demand (COD) and NH(4)-N reduction of dietary CP content led to a linear decrease of urinary (P < 0.05) and total (P < 0.05) N excretion, and N excretion/feed intake (P < 0.001). The emission of NH3 was similar in all diets (P > 0.05) during the 240 h of study. However, in the growing phase, the NH(3)-N level in slurry was lower (P < 0.05) for the low-CP diet. In addition, the CP level had no significant effect (P > 0.05) on total VFA, EC, TS, VS, COD or BOD(5) contents of excreta. These parameters were higher (P < 0.05) in slurry from the finishing phase than from the growing phase. However, NH(4)-N in the slurry decreased (P < 0.05) by 20.3% and 28.4% when the CP level was decreased by 9.30 or 21.40 g/kg, respectively. It is concluded that lowering dietary CP levels even by small amounts and using CP levels close to these used in commercial diets and close to the European Commission recommended values will decrease urinary and total N excretion in the slurry of growing-finishing pigs. The slurry from finishing pigs is more concentrated than that from growing pigs.

Potential of carvacrol to modify in vitro rumen fermentation as compared with monensin.

The aim of this study was to assess the effect of carvacrol supplement as a dietary additive to rumen fermentors, fed a barley seed:alfalfa hay (70:30) ration and to compare its effect with monensin supplementation. The material was incubated with goat ruminal fluid and four different treatments were included: no additive (C), 7.5 mg/l monensin (M), 250 mg/l carvacrol (C250) and 500 mg/l carvacrol (C500). The addition of carvacrol reduced in vitro dry matter (DM), crude protein (CP) and neutral-detergent fibre (NDF) digestion. The effects induced by C250 on DM digestion at 72 h of incubation were comparable with those of M, whereas a greater reduction was obtained when carvacrol was supplemented at 500 mg/l concentration (68.9, 68.5 and 53.0 v. 76.1% for M, C250 and C500 v. C, respectively). The reduced CP potential degradability by supplements (51.2, 53.9 and 51.5 v. 72.8% for M, C250 and C500 v. C, respectively) was mainly caused by a reduction of the slowly degradable fraction. Volatile fatty acid (VFA) profiles determined after 48 h of incubation showed C250 increased butyrate and decreased acetate proportions, whereas M mainly stimulated propionate proportions, suggesting that the mechanism of action of carvacrol and M differs. C500 significantly reduced total VFA production. Carvacrol could be of great interest for its usage as a potential modulator of ruminal fermentation. Future research, including in vivo studies, in order to understand the factors that contribute to its antimicrobial activity and the selection of the optimal dose is required.

Evaluación fermentativa del ensilado del subproducto de alcachofa (Cynara scolymus L. ) en tres niveles de un microsilo / Fermentative evaluation of the artichoke (Cynara scolymus L. ) by-product ensilage on three levels of microsilo

Se ha estudiado la evolución de indicadores fermentativos durante 50 días de ensilaje en el subproductoagroindustrial de alcachofa (Cynara scolymus, L). Las muestras se analizaron a intervalos regulares de tiempo(1, 2, 3, 4, 8, 12, 24 y 50 días), en tres fracciones del microsilo (inferior, medio y superior). El pH se estabilizóen los primeros 12 días de fermentación. El contenido de ácido láctico y acético fue diferente entre los días defermentación (p<0,001), pero las diferencias entre fracciones no fue significativa. El contenido de hidratos de carbono solubles fue diferente solo entre los diferentes días de ensilaje (p<0,001). Los resultados demuestran que no existen cambios estadísticamente signifi cativos entre las fracciones evaluadas demostrando un buen nivel fermentativo del ensilaje. Se puede concluir que el subproducto crudo de alcachofa es un material muy idóneo para ser conservado mediante ensilaje

The fermentative indicators evolution has been studied during 50 days of silage in the agro-industrial artichokeby-product (Cynara scolymus, L). The samples were analyzed at different sampling days (1, 2, 3, 4, 8,12, 24 and 50), in three fractions of the microsilo (botton, medium and top). The pH stabilized in the first 12 days. The lactic and acetic acids content was different between the sampling days (p<0.001), but the differences between fractions were not significatives. Water soluble carbohydrates content was different between the different ensiling days (p<0.001). No changes on pH have found and lactic or acetic acids and water solublecarbohydrates between the fractions evaluated. We can conclude that crude artichoke by-product will be suitableto be conserved by ensilage

Effect of thyme essential oils (Thymus hyemalis and Thymus zygis) and monensin on in vitro ruminal degradation and volatile fatty acid production.

The effect of the essential oils of thyme on the in vitro ruminal degradability of a barley seed/alfalfa hay substrate was studied. Two essential oils were used, one from Thymus hyemalis (TH), rich in carvacrol, and the other from Thymus zygis (TZ), rich in thymol. Four experimental treatments of in vitro degradability, using the Daisy II(200/220) incubator, were conducted including a negative control (CO), a positive control at 7.5 microg/mL of monensin (MO), and two treatments with essential oils (TH or TZ) at 1.35 microL/mL. The material was incubated at 39.5 degrees C for various lengths of time. At each time, the disappearance of dry matter, crude protein, and neutral detergent fiber was measured. Volatile fatty acids (VFAs) were determined after 48 h of incubation. CO and MO provided (p < 0.01) higher values of potential degradability (a + b) of DM than the TH and TZ treatments (72.6 and 70.8 vs 53.2 and 48.2%, respectively). Also, crude protein degradability was lowest in the essential oil treatments. The CO treatment showed the highest potential degradability of NDF. The values of VFA production obtained (p < 0.001) with CO and MO treatments were higher than those obtained with TH and TZ treatments (21.0 and 19.1 vs 11.2 and 10.1 mM). The essential oils decreased the molar proportion of propionate, increasing the acetate/propionate ratio. In conclusion, the effects of essential oils at assayed doses would not be nutritionally beneficial to the ruminal energetic metabolism.

Effect of formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens.

1. The effect of dietary formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens was studied. 2. An experiment with 120 Ross male broiler chickens was conducted from 1 to 42 d of age at the laboratory. There were 4 treatment groups: control (C), 10 mg/kg feed avilamycin (AV) and formic acid at two concentrations, 5 and 10 g/kg feed (FA5 and FA10, respectively). 3. No differences in weight gain, feed intake or feed conversion ratio were observed in male broiler chickens fed on the different diets. 4. An effect of the additives on ileal dry matter (DM) digestibility at 42 d of age was detected with the finisher diets; AV and 10 g/kg of feed formic acid slightly improved ileal DM digestibility compared to the other treatment groups. 5. Jejunum pH was not affected when 5 or 10 g/kg formic acid was added, and the results do not clearly show a positive effect of formic acid on the intestinal histomorphology. 6. No differences were noticed for blood metabolites in the different diets, and the levels of calcium and phosphorus in the plasma were not altered by formic acid addition. 7. In conclusion, when using broiler chickens under conditions of good hygiene, dietary formic acid did not have a clear positive effect on performance, intestinal histomorphology or plasma metabolite levels; however, there was a slight positive effect on the ileal digestibility of nutrients.

Influence of two plant extracts on broilers performance, digestibility, and digestive organ size.

A 42-d trial was conducted to study the influence of 2 plant extracts on performance, digestibility, and digestive organ weights in broilers. The feeding program consisted of a starter diet until 21 d and a finisher diet until 42 d. There were 4 treatment groups: control; 10 ppm avilamycin (AB); 200 ppm essential oil extract (EOE) from oregano, cinnamon, and pepper; and 5,000 ppm Labiatae extract (LE) from sage, thyme, and rosemary. No differences in feed intake or feed conversion were observed. From 14 to 21 d of age, broilers fed the LE diet grew faster than the broilers fed the control or EOE feeds (68.8 vs. 63.9 and 61.6 g/d, respectively). Antibiotic and plant extract supplementation improved apparent whole-tract and ileal digestibility of the nutrients. For starter feed, LE supplementation improved apparent fecal digestibility of DM (P < 0.01), and all additives increased ether extract digestibility (P < 0.001). However, no effect was detected for CP digestibility (P > 0.1). At the ileal level, the AB, EOE, and LE supplementation of the starter feed increased DM and starch (P < 0.01) digestibility but not CP digestibility (P > 0.1). All additives improved apparent fecal digestibility of DM and CP of the finisher diet. No differences were observed for proventriculus, gizzard, liver, pancreas, or large or small intestine weight. In the present study, both plant extracts improved the digestibility of the feeds for broilers. The effect of different additives on digestibility improved the performance slightly, but this effect was not statistically significant.

Efecto de la ración de los animales donantes de líquido ruminal sobre la degradabilidad in vitro de pajas y subproducto de limón / Effect of diet of the donor animals of ruminal fluid on the in vitro degradation of straws and lemon by-product

En el experimento se utilizaron cinco tipos de subproductos: paja, paja suplementada con urea, paja tratada con urea, paja tratada con urea+NaOH y un subproducto cítrico. La degradabilidad de cada subproducto fue determinada usando un método de fermentación in vitro con líquido ruminal de cabra. Se obtuvieron dos tipos de líquido ruminal dependiendo de la alimentación de las cabras (paja o heno de alfalfa). Los alimentos fueron incubados a 39ºC durante 12, 24, 36, 48 y 72 h con cada uno de los tipos de líquido ruminal. Para cada tiempo, se determinó la degradación de la materia seca. El origen del inóculo afectó significativamente (P<0.001) la fermentación in vitro. Los niveles menores de degradación de la materia seca fueron observados en las incubaciones con el líquido ruminal procedente de las cabras alimentadas con paja. La interacción, tipo de inóculo x tiempo de incubación fue significativa (P<0.001), así el incremento de la degradación entre las 12 y 24 h fue marcadamente superior en las incubaciones con el líquido ruminal de cabras alimentadas con heno de alfalfa. Así mismo, se determinó la concentración total de ácidos grasos volátiles y la proporción molar de cada ácido en el rumen a las 48 h. Los mayores niveles de ácidos grasos volátiles se observaron con el líquido ruminal procedente de las cabras alimentadas con heno de alfalfa. Estos datos confirman que la calidad de la dieta de los animales donantes de líquido ruminal afecta a la degradación y a la producción de productos finales de fermentación (AU)

Potential environmental impact of effluents from the artichoke (Cynara scolymus L.) byproduct ensiling process using additives.

Three treatments have been tested on canned artichoke byproduct after 50 days of ensilage: formic acid at 20% in doses of 2 mL. kg(-)(1) (FA), cane sugar molasses at 50 g.kg(-)(1) (M), and sodium chloride at 30 g.kg(-)(1) (SC). A fourth batch acted as a control group (C). The nutritive value, fermentation characteristics, environmental pollution effect, and total volume of effluents released have been studied. The highest nutritive value recorded was with SC silage. The use of the additives did not significantly improve the fermentation stability of the silage, but the total production of effluents in each treatment-52.7 (FA), 46.9 (M), and 55.2 (SC)-was significantly lower (P < 0.01) than that of the control group (70.1 L.Tm(-)(1)). The chemical oxygen demand (COD), 117300 mg of O(2).L(-)(1), and the conductivity, 46.4 microOmega(-)(1). cm(-)(1), were significantly higher (P < 0.01) in M and SC, respectively, than in the other group.