Histidine requirement of the young pig

A histidine (HIS)-deficient, feather meal-corn-dried whey basal diet (19% protein and 3,200 Kcal ME/kg), supplemented with lysine, methionine and tryptophan, was employed to determine the HIS requirement of the growing pig between 10 and 20 kg live weight. Using a chick bioavailability growth assay, the HIS-deficient basal diet was found to contain .19% bioavailable HIS. A preliminary pig study established that the HIS-deficient basal diet was capable of supporting good growth of pigs when supplemented with sufficient L-HIS.HCl.H2O. In the second pig experiment, crossbred pigs with an average initial weight of 10 kg were kept in individual metabolism crates and were fed to appetite in two feedings the HIS-deficient basal diet supplemented with 0, .06, .12 or .18% L-HIS. Rate and efficiency of weight gain increased linearly between 0 and .12% supplemental HIS, but the highest supplemental level of HIS did not improve performance further. Plasma HIS increased, whereas plasma urea-N remained unchanged, as the level of dietary HIS increased. The third pig experiment employed narrower increments of .06, .09 or .12% supplemental HIS, and a linear response in both gain and feed efficiency occurred. Viewing all experiments together, the bioavailable HIS requirement of the 10- to 20-kg pig was .31% of the diet. Assuming an 85% bioavailability of HIS in commercial diets based on corn and soybean meal, the total HIS level needed in practice would be .36%.     

Serum resistance and virulence of Escherichia coli isolated from turkeys

Twenty-five strains of Escherichia coli isolated from turkeys were characterized for their serum resistance and virulence. An in vitro bactericidal assay was used to determine the serum resistance of E coli. Virulence was determined by survival time after IV inoculation of each strain into 3-week-old turkeys. Serum-resistant E coli strains were generally found to be virulent for turkeys, whereas serum-sensitive E coli strains were avirulent. Of the 25 strains, 18 strains were placed in the 2 categories of serum-resistant/virulent and serum-sensitive/avirulent. Five strains were serum-resistant and avirulent, and 2 strains were serum-sensitive and virulent. Serum resistance appears to be an important determinant of virulence for E coli in turkeys; however, the requirement for other virulence factors, in addition to serum resistance, was suggested by the finding that 5 serum-resistant strains were avirulent in turkeys.     

Genotype dynamics of Campylobacter jejuni in a broiler flock

We investigated the genotype diversity and dynamics of Campylobacter in a commercial broiler flock during rearing and slaughter. In total, 220 Campylobacter jejuni isolates collected on four sampling occasions during rearing and from routine sampling during slaughter were subtyped by SmaI macrorestriction and pulsed-field gel electrophoresis, PFGE. Eight different SmaI types were found. During rearing, a subsequent addition of genotypes occurred, with two SmaI types found at 2 weeks of age and six types on the day before slaughter. All types that were detected in more than one isolate were also found on all succeeding sampling occasions, including the slaughter sampling. Two new types were found in the slaughter samples. In two-thirds of the individual birds sampled the day before slaughter, more than one SmaI type were found, although there was a clear tendency for dominance of one type in individual birds. Our results show that multiple genotypes of C. jejuni may be present in a commercial broiler flock during rearing and even in gastrointestinal tracts of individual birds. Both recurring environmental exposure and genetic changes within the population may explain the genotype diversity. Although the distribution of genotypes varied between different sampling occasions, we found no indication that any subtype excluded another during the rearing of the broiler flock.     

Effects of dietary quillaja saponin and curcumin on the performance and immune status of weaned piglets

The objective of this study was to determine whether dietary quillaja saponin and curcumin (extract of turmeric) can modify piglet immune status and performance immediately after weaning. Piglets (n = 192) were weaned at 29 +/- 0.1 d and allocated to treatment (six replicates of eight pig per treatment) accounting for weight, litter, and gender, using a 2 x 2 factorial arrangement. Factors were diets with or without (as-fed basis) quillaja saponin (750 mg/kg during wk 1, 300 mg/kg during wk 2 to 3) and with or without dietary curcumin (200 mg/kg). Diets were fed ad libitum for 20 d after weaning. Feed intake was measured daily. Piglets were weighed at weaning, d 7, 14, and 20 after weaning. On each of d 6 and 20 after weaning, eight pigs per treatment were sacrificed for blood and tissue collection. Treatment had no effect on piglet growth. The ADFI and G:F were similar for all treatments between d 0 and 14 of the trial. Between d 15 and 20, ADFI and G:F were lower in quillaja-supplemented piglets (ADFI = 621 vs. 572 g/d; G:F = 0.75 vs. 0.85; P < 0.05). Serum immunoglobulin (Ig) G, IgA, interferon-gamma, and C-reactive protein (CRP) did not differ among treatments on d 6 after weaning. On d 20, IgG and CRP were greater (P < 0.05) in saponin-supplemented pigs (IgG = 17.5 vs. 11.4 mg/mL; CRP = 26.98 vs. 12.5 mg/mL). Small intestine villus and crypt measurements did not differ among treatments on either d 6 or 20. Saponin supplementation during the postweaning period seemed to potentiate an immune response in the weaned piglet but had a detrimental effect on the utilization of feed. Dietary curcumin had no influence on any measured aspect of pig performance or immune status.     

A literature review of equine piroplasmosis after an episode of acute babesiosis in a Dutch Standardbred foal after a stay in Normandy

Piroplasmosis, a disease endemic to most tropical and subtropical areas, appears to be spreading to more temperate zones. This article gives a review of equine piroplasmosis and describes an acute case of infection with Babesia caballi in a Dutch Standard bred foal after a short stay at a stud in Normandy (France). A 3-month-old stallion foal was presented with lethargy, fever of 41 degrees C, and pale mucosal membranes. Haematology revealed a low packed cell volume (14 l/l) leucytosis (25 G/l) and a high blood urea nitrogen concentration (20.1mmol/l). Infection with B. caballi was diagnosed on the basis of Giemsa staining blood smears and was confirmed by polymerase chain reaction in combination with RLB. Treatment with imidocarb dipropionate and a blood transfusion resolved the haemolytic crisis.     

Housing- and management-specific effects on the health of swine

Important diseases with regard to inadequate housing and management conditions in pig production are given. Typical examples like claw lesions, cannibalism and infectious factorial diseases are described. Beside negative factors of pig housing and management which are of particular pathogenic importance some aspects of disease control and herd health are listed finally.     

The use of disinfectants in veterinary practice

The use of chemical disinfectants within the veterinary practice is only permitted when the disinfectants are legally registered. A distinction has to be made between disinfectants to be used on the skin of men or animals and disinfectants to be used on surfaces like floors, walls, cages, stables and for veterinary instruments. For the first group, to be considered as (veterinary) medicines, the Act on (Veterinary) Medicines applies. For the second group, to be considered as veterinary biocides, the Pesticide Act applies. A small survey carried out by the Keuringsdienst van Waren shows that in veterinary practice disinfectants are applied in an inappropriate way. A lack of knowledge and the lack of hygienic protocols could be reasons for these misuses. In this article the Keuringsdienst van Waren gives information about the legal aspects of disinfectants that fall within the scope of the Pesticide Act.     

Differential expression of genes implicated in liver lipid metabolism in broiler chickens differing in weight

ABSTRACT

1. Lipid parameters and expression of ACACA, APOA1, CPT1A, FASN, FOXO1, LIPG, PPARα and SIRT1 genes involved in lipid metabolism were investigated in two groups of high (HW) and low (LW) weight broilers from the same strain.

2. Blood cholesterol and liver triglyceride levels were significantly increased in HW chickens compared to LW broilers, while other parameters, i.e. blood triglyceride, blood HDL/LDL, liver cholesterol and total liver fat showed no significant changes in either group.

3. The relative expression of ACACA, APOA1 and CPT1A genes was significantly lower in the liver tissues of HW broilers than in the LW group. The mRNA levels of these three genes showed a significant negative correlation with abdominal fat deposition and live weight of broilers. However, relative expression of FASN, FOXO1, LIPG, PPARα and SIRT1 hepatic genes did not differ among broilers.

4. It was concluded that, of eight hepatic genes implicated in lipid metabolism, only the expression of three (ACACA, APOA1 and CPT1A) were significant for fat and leanness within the same strain of chicken. Since reducing body fat is a major goal in the broiler industry, these data can provide fresh insight into the molecular processes underlying the regulation of fat deposition in broilers.     

Longitudinal data collection of Mycobacterium avium subspecies Paratuberculosis infections in dairy herds: the value of precise field data

Longitudinal infection data on Mycobacterium avium subspecies paratuberculosis (MAP) was collected on three dairy farms in Northeastern United States during approximately 10 years. Precise data on animal characteristics and animal location within farm were collected on these farms. Cows were followed over time with regard to MAP status during biannual fecal and serum sampling and quarterly serum sampling. Approximately 13 000 serum samples, 6500 fecal samples and 2000 tissue samples were collected during these years. Prevalence of positive samples was 1.4% for serological samples, 2.2% in fecal samples and 16.7% in tissue samples. Infection dynamics of MAP was studied and resulted in a number of potential changes in our understanding of MAP infection dynamics. First, a high prevalence of MAP infection was observed in these herds due to lifetime follow up of cows, including slaughter. Second, two distinctly different infection patterns were observed, so called non-progressors and progressors. Non-progressors were characterized by intermittent and low shedding of MAP bacteria and a virtual absence of a humoral immune response. Progressors were characterized by continuous and progressive shedding and a clearly detectable and progressive humoral immune response. Strain typing of MAP isolates on the three farms identified on two of three farms a dominant strain type, indicating that some strains are more successful in terms of transmission and infection progression. Continuous high quality longitudinal data collection turned out to be an essential tool in our understanding of pathobiology and epidemiology of MAP infections in dairy herds.