Effects of dietary benzoic acid and sodium-benzoate on performance, nitrogen and mineral balance and hippuric acid excretion of piglets.

The objective of this study was to compare the effects of sodium-benzoate (NaB) with those of benzoic acid (BAc) on growth performance of piglets as well as nutrient digestibility, nitrogen and mineral balance, urinary pH, and the urinary excretion of BAc and hippuric acid (HAc). The study was conducted with 120 weaning piglets (6.5 kg body weight), divided in four groups (15 replicates of two piglets each), which received (1) a basal diet (Control), or the basal diet supplemented with (2) 4 g NaB per kg (Group 4NaB), (3) 3.5 g BAc per kg (Group 3.5BAc) or (4) 5 g BAc per kg (Group 5BAc). Performance data were monitored over a 42-day period. Urine and faeces were collected from day 28-33 in metabolic cages with five piglets per treatment. Piglets of Groups 3.5BAc and 5BAc had similarly a considerably improved average daily gain and feed intake (p < 0.05). Performance of Group 4NaB was not significantly different from the other groups. Compared to the Control, the nitrogen retention was only improved in Group 5BAc (p < 0.05); the other groups showed intermediate values. In the supplemented groups, most of the BAc was excreted as HAc in urine, but only Groups 3.5BAc and 5BAc had reduced urinary pH (p < 0.05). Daily intake and faecal and urinary excretion of P and Ca were not affected by the treatment. The molar excess of Na in Group 4NaB was reflected by higher renal excretion of Na compared to the other groups (p < 0.05).

Influence of benzoic acid in high fibre diets on nutrient digestibility and VFA production in growing/finishing pigs.

In a feeding trial with 32 crossbred gilts (13-108 kg bodyweight) the effect of benzoic acid (5 g/kg diet) in low (NDF: 150 g/kg DM) and high (NDF: 202 g/kg DM) fibre diets on performance and apparent nutrient digestibility was examined. The animals were restrictively fed one of four grower and finisher diets: low fibre diet without and with benzoic acid (LF- and LF+), and a high fibre diet without and with benzoic acid (HF- and HF+). At 56 kg bodyweight, four animals per diet were slaughtered to obtain data on volatile fatty acid (VFA) production in the gut. In the grower period, digestibility of nitrogen, energy and neutral detergent fibre was positively influenced by benzoic acid (p < 0.01) and reduced by fibre addition (p < 0.01). The concentration of butyric acid in caecum and colon was increased by benzoic acid (p < 0.05). Dietary fibre content did not influence VFA concentrations. It is concluded that the addition of benzoic acid helped animals to utilise high fibre diets better.

Effect of xylanase on apparent ileal and total tract digestibility of nutrients and energy of rye in young pigs.

A digestibility experiment was carried out on weanling piglets to study the effect of an enzyme complex with predominant xylanase activity on apparent ileal (AID) and apparent total tract digestibility of nutrients and energy. The enzyme was supplemented at four levels (0, 50, 100 and 200 mg/kg) to a diet containing 96% rye. There were significant effects of the added enzyme on AID of dry matter, organic matter and crude fibre, and on apparent total tract digestibility of dry matter, organic matter and energy. However, the improvements in the digestibility were rather small. Except for galactose, there was a significant response in AID of all non-starch polysaccharide constituents to enzyme supplementation, the greatest effect being found at 100 mg/kg. The improvement in AID of arabinose + xylose (685%) was much higher than that of the remaining sugars (110%). AID of galactose was negative in all dietary treatments, presumably due to its high concentration in endogenous secretions. There was a significant response in AID of the sum of essential and total amino acids to the increased level of the enzyme. It is concluded that the enzyme complex is efficient in degrading dietary fibre components, thus improving the digestibility of organic matter, amino acids and energy.

Effects of lactoferrin feeding on growth, feed intake and health of calves.

Lactoferrin (LF) exhibits a broad spectrum of anti-microbial properties and may have regulatory functions in the immune system. In the present study, 40 calves (20 males, 20 females) were used to examine the effects of supplemental bovine LF added to colostrum and milk replacer (at 0.16%) on health, weight development and feed intake during a 70-day experimental period. The calves were allocated to a treatment group (n = 20) and a control group (n = 20); the groups were balanced in terms of sex, live weight and date of birth. Body weight and feed intake were measured at regular intervals. Blood and colostrum samples were collected to determine the content of IgG. In addition, colostrum and milk replacer samples were analysed for their LF concentrations. Significantly higher IgG values were observed in the LF treated than in the control group during the entire feeding experiment from week 2 to week 6. Calves receiving LF had less days of disease with less serious cases of diarrhoea than the control group. Body weight and feed intake were not significantly different between the treatments; in male calves LF-treated animals tended towards higher weight gains. This study indicates that LF is advantageous for health and may therefore be a beneficial supplement in the diets for neonatal calves.

Influence of benzoic acid and dietary protein level on performance, nitrogen metabolism and urinary pH in growing-finishing pigs.

An experiment was conducted to examine the effect of benzoic acid and two dietary protein levels on pig performance, nitrogen balance and urinary pH. A total of 24 crossbred barrows (26 kg to 106 kg BW) received one of four diets: low protein level with and without 1% benzoic acid (LP- and LP+, respectively) and high protein level with and without 1% benzoic acid (HP- and HP+, respectively). The animals were fed restrictively grower and finisher diets and were kept in metabolic cages in weeks 3, 6, 9, and 12 of the experiment. The addition of benzoic acid did not improve weight gain and feed conversion ratio. N-intake and digested N were only influenced by dietary protein level (p< 0.01), while N-balance was similar in all four diets. Dietary benzoic acid improved N-digestibility in the grower period (p<0.01) but not in the finisher period. The addition of benzoic acid reduced urinary pH by about one pH-unit in both feeding periods independent of the protein level of the diet (p< 0.01) and increased the concentration of urinary hippuric acid markedly (p<0.01). The results of this study indicate a positive influence of dietary benzoic acid on pigs especially in case of feeding a low protein diet in the grower period.

Phosphorus equivalence of a Consensus phytase produced by Hansenula polymorpha in diets for young turkeys.

An experiment was conducted to determine the efficacy of a so-called consensus phytase preparation produced by Hansenula polymorpha on growth, tibia and toe ash and P retention of young turkeys. A total of 192 female turkeys (BUT 9 strain) were placed into 96 batteries at two per cage and assigned to one of eight diets: A negative control containing 2.5 g non-phytate P per kg feed (T-1); T-1 plus 125, 250, 500, 1000 or 10 000 phytase units (U) per kg feed, respectively, (T-2 to T-6); T-1 plus 0.5 or 1.0 g Pi/kg feed as dicalcium phosphate dihydrate (DCP), respectively, (T-7 and 8). The experiment lasted 32 d, and excreta were collected and weighed between 26 and 29 d of age. Feed was also weighed during this period in order to calculate P retention. Performance was calculated for the 0 to 32 d period. At the end of the experiment one bird per pen was killed for tibia and toe ash content determination, except for T-2, T-3, and T-7. Body weight, FCR, toe and tibia ash, and P retention responded to phytase or Pi supplementation. Using linear or quadratic models for comparing performance of the treatments containing supplemental Pi with phytase treatments, an equivalence between phytase and Pi was calculated. Body weight, toe ash, tibia ash and P retention showed a significant response to phytase supplementation. The values of equivalence for body weight, toe ash, tibia ash and P retention were 251, 597, 391 and 390 U to 1 g Pi/kg feed. At 10 000 U/kg feed there was a significant response in terms of weight gain and P retention, indicating that turkeys respond to levels greater than 1 000 U/kg feed.