J. Orengo

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.

Effects of low protein diets on growth performance, carcass traits and ammonia emission of barrows and gilts

The aim of the present research was to determine the effect of low protein diets on growth performance, carcass traits and ammonia emission from barrows and gilts during the growing and finishing periods. For each period, three diets were formulated. A control diet (C) with 160 and 155 g crude protein (CP)/kg for the growing and finishing, respectively, a medium level diet (M) and a low level diet (L) with 10 and 20 g CP/kg less than the C, respectively. All the diets were supplemented with crystalline amino acids on an ideal protein basis. Barrows (90) and gilts (90) were sorted by bodyweight and sex and housed in three identical manually ventilated chambers. No significant effects of diet on pig performance were observed. In the finishing period, barrows were heavier (P 0.05) by sex. Average ammonia emissions during the last 6 days were 117.7, 94.2 and 85.5 mg ammonia/kg pig.day for pigs fed the C, M and L diets, respectively. The results show that a reduction in dietary CP of 10 g/kg, accompanied by supplementation with crystalline amino acid reduced ammonia emission by 19.9% with no detrimental effects on growth performance and carcass characteristics, and a reduction of 20 g/kg reduced ammonia emission by 27.3% with no detrimental effects on growth performance but reduced muscle depth at slaughter.

Causes, consequences and biomarkers of stress in swine: an update

BackgroundIn recent decades there has been a growing concern about animal stress on intensive pig farms due to the undesirable consequences that stress produces in the normal physiology of pigs and its effects on their welfare and general productive performance. This review analyses the most important types of stress (social, environmental, metabolic, immunological and due to human handling), and their biological consequences for pigs. The physio-pathological changes associated with stress are described, as well as the negative effects of stress on pig production. In addition an update of the different biomarkers used for the evaluation of stress is provided. These biomarkers can be classified into four groups according to the physiological system or axis evaluated: sympathetic nervous system, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-gonadal axis and immune system.ConclusionsStress it is a process with multifactorial causes and produces an organic response that generates negative effects on animal health and production. Ideally, a panel of various biomarkers should be used to assess and evaluate the stress resulting from diverse causes and the different physiological systems involved in the stress response. We hope that this review will increase the understanding of the stress process, contribute to a better control and reduction of potential stressful stimuli in pigs and, finally, encourage future studies and developments to better monitor, detect and manage stress on pig farms.

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.

Efficiency of a prebiotic and a plant extract alone or in combination on broiler performance and intestinal physiology

A 36-d trial was conducted to evaluate two potential alternatives to antibiotic growth promoters in broilers. The products tested were a prebiotic (PROFEED®) and a plant extract (XTRACT™). Ross male broiler performance and digestive tract function responses were studied. To evaluate the effect of these potential alternatives alone or in combination, seven diets were tested: positive control avilamycin 10 ppm (PC); negative control antibiotic-free (NC); NC + PROFEED® 600 ppm (P); NC + XTRACT™ 100 ppm (X); NC + PROFEED®/XTRACT™ 600/100 ppm (XPH); NC + PROFEED® /XTRACT™ 450/75 ppm (XPM); NC + PROFEED®/XTRACT™ 300/50 ppm (XPL). From 22 to 36 d of age, body weight gain (BWG) was improved by P, X, and XPM compared with NC (P < 0.05). Throughout the trial, broilers fed PC, P, X and XPL had a better feed conversion ratio (FCR) than those fed NC (P < 0.1). No relevant negative effect was observed for the parameters relative to the digestive tract function: ileal histomorphometry, anaerobic sulphite-reducing bacter...

Crude glycerine inclusion in Limousin bull diets: animal performance, carcass characteristics and meat quality.

Three hundred and six Limousin young bulls (7±1months of age, initial body weight 273±43kg) were used to evaluate the effect of crude glycerine supplementation on animal performance, carcass characteristics and meat quality. Animals were assigned to three different diets: Control (0% of crude glycerine), G2 and G4 (2 and 4% of crude glycerine, respectively). The diets were administrated ad libitum for 240days (final body weight 644±24kg). Average daily weight gain, average daily feed intake, the gain:feed ratio, ultrasound measures in vivo, carcass characteristics, pH, water holding capacity, drip losses, and cooking losses were not affected (P>0.05) by diets. Diet decreased C16:0 (P<0.01) and C16:1 (P<0.05) contents in meat. The G4 meat showed lower C12:0, C14:0, C17:0, C18:0, C18:1, C18:2, C18:3, c9,t11-c18:2, C20:0 and C20:4 levels (P<0.05) than control. Glycerine increased desirable fatty acid percentages (P<0.05) in intramuscular fat.

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.

Polysaccharidase preparations added to a wheat-based diet: effects on performance and digestive parameters of broiler chickens held at three different locations.

1. Three experiments of 39 d were simultaneously conducted to assess the efficacy of three carbohydrase combinations on performance, apparent nutrient digestibility, intestinal morphology and digestive organ relative weights of chickens fed on a wheat-based diet. 2. Experiment 1 was performed under laboratory conditions, with the birds housed in cages. In experiment 2, the birds were placed in floor pens built in a commercial farm, and raised with their contemporaries at the farm. In experiment 3, broilers were reared under industrial management circumstances in commercial farms. A two-phase feeding programme was used: starter from 1 to 21 d of age and finisher from 22 to 39 d. The basal diet without supplementation (BD) and three enzyme preparations (BDF, BDP and BDR) were evaluated. 3. No differences in growth traits were observed among treatments in experiments 1 and 2. 4. When overall growing period was evaluated, all enzyme combinations improved apparent DM ileal digestibility of feed in the three experiments, but significant differences were only found in experiments 2 and 3. For this same period, an increase in apparent CP ileal digestibility of broiler chickens fed supplemented diets against the control group was found in experiment 3. Moreover, a significant greater apparent ileal fat digestibility in the enzyme treatments compared with the control group was shown when broilers were raised under industrial conditions (experiment 3). 5. Enzyme combinations had no effect on villus heights and crypt depths of broilers in experiment 1, whereas, in experiment 2, a greater villus height was found in BDF and BDP treatments than in control birds. 6. There were no differences in digestive organ relative weights among dietary treatments except for pancreas in experiment 1.

Response of broilers to feeding low-calcium and total phosphorus wheat-soybean based diets plus phytase: Performance, digestibility, mineral retention and tibiotarsus mineralization

A 42-d trial was conducted with broilers fed a wheat-soy bean-meal-based diet to compare three dietary levels of calcium (Ca) and total phosphorus (TP) plus phytase on growth performance parameters, nutrient digestibility, mineral retention and tibiotarsus bone parameters. Three treatments were compared: a high Ca and TP diet (H−; according to NRC recommendations) without addition of phytase; a moderate Ca and TP diet (M+) with 600 U kg-1 of phytase; and a low Ca and TP diet (L+; similar to local industry practices) with 600 U kg-1 of phytase supplementation. Feed intake and weight gain of broilers fed H− were not different to M+ or L+. Nutrients digestibility at 21 d was improved in animals fed M+ in comparison with H− and L+. Better phosphorus retention was observed for M+ at 21 d of age. The bone mineralization was similar for H− and M+ at 21 d of age, and for H−, M+ and L+ at 42 d of age.

Effect of feeding on hormones related with feed intake in reproductive sows with different energy balances

Martínez, S., Valera, L., Villodre, C., Madrid, J., Orengo, J., Tvarijonaviciute, A., Cerón, J. J. and Hernández, F. 2014. Effect of feeding on hormones related with feed intake in reproductive sows with different energy balances. Can. J. Anim. Sci. 94: 639-646. The different phases that occur during the reproductive life of the sow involve different energy balances, which can affect the levels of hormones that regulate appetite. This study analyzes the behaviour of serum insulin, leptin, ghrelin, cortisol and butyryl-cholinesterase, before and after feeding in pregnant, lactating and post-weaning sows. Hormones were analyzed in blood samples, which were collected after fasting overnight (0 min) and 30 min after feeding at day 109 of pregnancy, at day 9 post-farrowing and at day 3 post-weaning. Before feeding, insulin and leptin levels were not statistically different between reproductive stages. Feeding increased serum insulin and leptin levels of pregnant sows, increased insulin and decreased leptin levels in lactating sows, but had no effect on post-weaning sows. Deacylated ghrelin was higher in pregnant sows and acylated ghelin in post-weaning sows before feeding. Feeding intake did not affect the concentration of deacylated and acylated ghrelin in any group. Cortisol was positively correlated with acylated ghrelin before feeding in pregnant and lactating sows, and negatively with deacylated ghrelin before and after feeding in pregnant sows. There was a negative correlation between deacylated and acylated ghrelin before and after feeding in pregnant and post-weaning sows. So, sows with different energy balances had different insulin, acylated ghrelin and cortisol dynamics before and after feeding, suggesting that these analytes could be used as biomarkers to detect situations resulting in a poor energy balance in order to improve handling programs.