J. Madrid

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.

A comparative study on the determination of lactic acid in silage juice by colorimetric, high-performance liquid chromatography and enzymatic methods

The determination of lactic acid in the silage juice of artichokes with different additives (formid acid, molasses and NaCl) by the colorimetric method and its comparision with the high-performance liquid chromatography and enzymatic methods was investigated. The lactic acid content of the artichoke with molasses (62.1 g kg−1) was higher than that of those with formic acid, or NaCl and without any additive (39.3, 33.0 and 43.2 g kg−1, respectively). However, this effect was not significant (P > 0.05). There were significant differences on the method of measuring lactic acid of the artichoke silages (P < 0.001). The use of the enzymatic method resulted in a higher (75.6 g kg−1) lactic acid content than when the colorimetric or HPLC methods were employed (with results of 42.0 and 28.9 g kg−1, respectively). However, the levels of lactic acid in silage juices found using the colorimetric and HPLC methods were not different, and recovery percentages, by using the colorimetric method, were satisfactory (103.78%), when the detection limit at maximum level (30 µg ml−1) was not exceeded. © 1999 Society of Chemical Industry

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.

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.

Acute Phase Proteins in Experimentally Induced Pregnancy Toxemia in Goats

The present work aimed to study the behavior of acute phase proteins (haptoglobin, serum amyloid A, acid soluble glycoprotein, fibrinogen, and albumin) in fasting-induced pregnancy toxemia in goats and their relationship with classical indicators of this disorder such as beta-hydroxybutyrate and nonesterified fatty acids in the blood and decreased urine pH and ketonuria. Twelve adult Murciano–Granadina goats at the final stage of gestation were used in this experiment. Pregnancy toxemia was induced in 6 goats by fasting for 72 hr. The other 6 animals were used as control group. Ketonuria was present in 4 out of 5 fasting animals at 24 hr and in all fasting animals at 48 hr of fasting. Serum nonesterified fatty acids were significantly increased at 24, 48, and 72 hr of fasting. Beta-hydroxybutyrate and haptoglobin achieved significantly increased concentrations at 48 hr and 72 hr, respectively, remaining increased during the entire study. Serum amyloid A, acid soluble glycoprotein, fibrinogen, and albumin were not affected by fasting. In conclusion, acute phase proteins (including haptoglobin) seemed not to have an advantage over traditional markers in diagnosis of fasting-induced pregnancy toxemia in goats.

Urea and citrus by-product supplementation of straw-based diets for goats: effect on barley straw digestibility

Abstract Voluntary intake and in vivo digestibility of barley straw based diets supplemented with citrus by-product and urea were determined in 24 castrated male goats of the Murciano-Granadina breed in a digestion trial. Daily DM and digestible OM intake of diets increased ( P P −1 LW 0.75 as higher levels of citrus by-product were included in the diets. DM and OM digestibilities of the diets increased ( P P P

Effects of citrus by-product supplementation on the intake and digestibility of urea+sodium hydroxide-treated barley straw in goats

Abstract Sixteen castrated male goats of the Murciano–Granadina breed were used to determine the effect of citrus by-product supplementation on the intake and digestibility of urea+NaOH-treated barley straw. Barley straw was treated with urea (40 g kg −1 DM) and sodium hydroxide (10 g kg −1 DM) and was offered supplemented with citrus by-product at 0, 100, 200, 300 g DM animal/day in four digestibility trials in a completely randomised block design. Digestible organic matter intake was changed ( P P P >0.05) in CP or fibrous fraction digestibilities among the four diets. The digestibility of treated straw was assessed for differences. Organic matter digestibility was different ( P P >0.05). These results suggest that digestibility or intake of DM and OM in a diet based on urea+NaOH-treated barley straw could only be improved by supplementation at modest levels with citrus by-product.

Nutritive value of Kochia scoparia L. and ammoniated barley straw for goats

Chemical composition, in vivo digestibility and usable energy value of kochia (Kochia scoparia L.) were determined using goats of Murciano—Granadina breed. Fifteen mature goats were fed fresh kochia substituting ammoniated barley straw at 0, 25, 50, 75 or 100% of their complete diets in a completely randomized experimental condition. There were no differences (P > 0.05) in DMI or DMD or OMD among the five diets containing kochia and treated straw. Kochia substitution resulted in a quadratic increase (P < 0.001) in N digestibility as rising levels of kochia replaced treated straw. In contrast, the substitution of treated straw with kochia in increasing amounts resulted in a decline (P < 0.001) in NDF, ADF and cellulose digestibilities. ME content of kochia (5.7 MJ kg−1 DM) was significantly (P < 0.001) lower than treated straw (8.1 MJ kg−1 DM). However, four kochia diets had a low ME content. This result suggests the possible role of kochia in a grazing system for goats, during periods, such as the hot season, in which pasture availability in the Mediterranean regions is reduced.

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.