The effect of feeding antibiotic growth promoters on the performance of beef cattle consuming forage-based diets: A review

Scientific literature on the use of antibiotic growth promoters (AGP) in beef cattle consuming forage-diets was reviewed. Database summarizes 136 comparisons between untreated and AGP-treated cattle from 48 bibliographic references. Performance data of cattle receiving AGP either alone or in combination with 17 β-estradiol implants was statistically analyzed. Forage quality, in terms of average daily gain (ADG), differentially influenced (P = 0.1) the effect of AGP on beef cattle performance. As the quality of forage increased, the estimated net ADG response to monensin decreased and that to lasalocid increased. ADG increased quadratically (P < 0.01) with increasing doses of monensin (R² = 0.71) or lasalocid (R² = 0.63). Ionophore-dosage level quadratically improved (P = 0.01; R² = 0.52) feed conversion (FCONV) of cattle without affecting their dry matter intake (DMI; P > 0.1). A linear relationship (P < 0.01) between ADG and dose of tetronasin (R² = 0.64) or lysocellin (R² = 0.52) was also observed. The combination of monensin and 17β-estradiol implants resulted in an additive effect on ADG of grazing cattle. The experimental results reviewed show that, in beef cattle consuming forage-based diets, ionophores improve ADG and FCONV in a dose-dependent manner, with little or no effect on DMI. In addition, results suggest that forage quality influences the direction of the ADG response to AGP supplementation in cattle. Summarized data from beef cattle implanted with 17β-estradiol and/or supplemented with monensin indicate that the combined response of these two compounds on cattle grazing high-quality pastures has no effect on ADG over that obtained by 17β-estradiol alone.     

Gastric Helicobacter species as a cause of feline gastric lymphoma: a viable hypothesis

Gastric Helicobacter spp. are associated with chronic inflammation and neoplastic transformation in humans as well as domestic and laboratory species. The present study examined the association of Helicobacter heilmannii (Hhe) infection in pet cats with feline gastric mucosa associated lymphoid tissue (MALT) lymphoma. Tissues were collected via gastric biopsy or at necropsy from 47 pet cats with clinical signs of gastrointestinal disease, including vomiting and inappetance, and classified as gastritis (14/47), lymphoma (31/37), or normal (2/47). Tissues positive for argyrophilic organisms with Warthin–Starry stain (29/47) were assessed by fluorescent in situ hybridization (FISH) for the presence of Hhe strains 1–4 as well as with a fifth probe that detected Helicobacter salomonis, Helicobacter bizzozeronii, or Helicobacter felis. A significant association of positive Warthin–Starry status with Hhe infection was found in cases of sick cats (22/29; p < 0.05 by Chi-square; χ² = 7.034). Interestingly, a significant association between Hhe status and a diagnosis of lymphoblastic or lymphocytic lymphoma was observed as well in a subset of 24 Warthin–Starry positive lymphoma cases: of lymphoblastic lymphoma cases, 13/17 were positive for Hhe (p < 0.05; χ² = 4.854). Hhe strains 2 and 4 were most commonly found (18/29 and 17/29, respectively) among sick cats, although a higher than expected number of cats was also positive for Hhe1, which initial reports have described as rare in cats and common in humans. The association found between a positive Hhe status with the presence of feline gastric lymphoma, especially lymphoblastic lymphoma, argues for the need to conduct prospective studies to better identify the frequency and strain distribution of Hhe infection in both healthy and clinically ill cats, particularly those cats with gastric lymphoma.     

The correlation between passage rate of digesta and dry matter digestibility in various stages of swine

The relationship between passage rate of digesta (PRD) and apparent faecal dry matter digestibility (DMD) was investigated in five trials. In trial 1, 2, and 3, 36 weanling (16.9 ± 3.0 kg), 24 growing (51.3 ± 8.8 kg), and 23 finishing (104.8 ± 5.2 kg) barrows were housed in metabolic crates. The beginning and end of 5-day collection periods were marked by the addition of 0.5% indigo carmine to the feed for total faeces collection and PRD determination by observing the time required for the marker to appear. In trial 4 and 5, 21 gestating gilts (215.0 ± 15.0 kg), and 19 lactating sows were individually penned. Addition of 0.5% chromic oxide to the feed enabled indirect determination of DMD and PRD. The PRD, which ranged from 12 to 80 h, was positively correlated with DMD in weanling (R² = 0.483, P < 0.001), growing (R² = 0.425, P < 0.01), and finishing (R² = 0.553, P < 0.001) pigs. Body weight and DMD were not significantly correlated in weanling (R² = 0.001, P = 0.893), growing (R² = 0.000, P = 0.995), or finishing (R² = 0.092, P = 0.156) pigs. A positive correlation between PRD, which ranged from 27 to 102 h, and DMD occurred in gestating gilts (R² = 0.231, P < 0.05), but not in lactating sows (R² = 0.014, P = 0.633). The results indicate that longer retention times of digesta improve DMD in swine. Also the results indicate the importance of PRD as a potential independent variable in digestibility assessments.     

Equine trypanosomosis in the Central River Division of The Gambia: a study of veterinary gate-clinic consultation records

The objective of this study was to provide epidemiological information of equine trypanosomosis in the Central River Division (CRD) of The Gambia. Therefore, 2285 consultations records of equines, admitted in a gate-clinic at Sololo in CRD, were studied retrospectively. The data were recorded in the period between September 1995 and July 2002 and comprised consultations of 2113 horses and 172 donkeys.

‘Trypanosome infection’ was the most frequently diagnosed condition and accounted for 61% of the cases. Horses were more frequently diagnosed with trypanosome infections than donkeys (p < 0.001), with an occurrence of 63% compared to 43% in donkeys. In both horses and donkeys, trypanosome infections were mainly due to Trypanosoma congolense (64%) and T. vivax (32%). There was no difference observed in the occurrence of trypanosome infections in male or female donkeys (p = 0.585), but there were more female (67.8%) horses observed with trypanosome infections than male horses (60.7%; p = 0.003). There was no difference observed in the occurrence of trypanosome infections in donkeys older or younger than 1 year (p = 0.130), but more older horses (63.2% >1 year) were observed with trypanosome infections than young horses (54.5% <1 year; p = 0.033).

The number of donkeys and horses with trypanosome infections decreased during the rainy season (June–September).

The majority of equines that were admitted with trypanosome infections were severely anaemic. The average packed cell volume (PCV) declined with increasing parasitaemia (p = 0.006).

Seventy-four percent of the farmers’ predictions of trypanosome infections in their equines were confirmed by darkground-microscopy. That proved that farmers had a fairly accurate knowledge of the diseases affecting their equines.

The treatments executed at the gate-clinic were generally effective. The few (0.4%) relapses of the T. vivax infections that were previously treated with diminazene aceturate in this study were not sufficient to prove drug resistance.

The study showed that the analysis of consultation records at a gate-clinic can provide complementary information to conventional epidemiological studies in the same research area.     

A cross-sectional study of epizootic lymphangitis in cart-mules in western Ethiopia

A cross-sectional study was conducted to determine the prevalence of epizootic lymphangitis (EL) in 309 cart-mules (cart-pulling mules) in Bako and Ejaji towns, Western Ethiopia using clinical and microbiological examinations, between November 2002 and April 2003. The overall prevalence was 21% (CI = 16.6–26%). The clinical, histological and mycological characteristics of EL in a cart-mule were similar with those in a horse. There was significant (χ² = 133.5, P = 0.001) association between tick infestation and EL lesions in study cart-mules. Amblyoma coherence and Boophilus genera were the ticks collected from lesions of cases of EL, and thus played a predisposing role. In conclusion, our results showed that EL has high prevalence in cart-mules in the two towns.     

Canine intestinal helminths in Finland: prevalence, risk factors and endoparasite control practices

In this survey, the prevalence of canine gastrointestinal helminths in Finland was investigated by coprological examination (n = 541) and possible risk factors for helminth infections in dogs were analysed. In addition, the dog owners (n = 296) completed a questionnaire about use of anthelmintics, sources of information about parasites and antiparasitic treatments and reasons for choosing the drugs.

The prevalence of gastrointestinal helminths was 5.9%. Eggs from four different species were identified in the faecal samples. Toxocara canis eggs were present in 17 dogs (3.1%), Uncinaria stenocephala eggs in 14 dogs (2.6%) and Diphyllobothrium latum eggs in 2 dogs (0.4%). Moreover, one sample contained eggs of Trichuris vulpis (0.2%). Kennel housing and visits abroad were identified as risk factors for T. canis and U. stenocephala infections.

Most dogs (86.0%) received anthelmintic treatment at least once a year. Hunting dogs were dewormed least; one-third was treated less than once a year. Approximately, half of the owners occasionally changed the anthelmintic used. The most important trait of the anthelmintic was its broad spectrum, fenbendazole being the most commonly chosen. Veterinarians, dog magazines and dog breeders were the predominant sources of information concerning parasites and deworming strategies.     

The use of purine derivatives/creatinine ratio in spot urine samples as an index of microbial protein supply in Yerli Kara crossbred cattle

Three experiments were conducted to evaluate the use of purine derivatives (PD)/creatinine ratio in spot urine samples as an index of microbial protein supply in Yerli Kara crossbred cattle (YK-C). In Experiment I, response of daily PD excretion to feed intake in YK-C at state farm was measured. In Experiment II, spot urine sampling techniques was applied at state farm and four YK-C bulls were used. In Experiment III, spot urine sampling technique was applied at small-holder farms. There were significant correlations (R² = 0.99) between PD excretion (mmol/day) and digestible organic matter intake (DOMI) (kg/day) in Experiment I, Y = 12.5 (± 0.5) + 19.7 (± 3.5)X (R² = 0.99, n = 16). The equation obtained from Experiment I could be expressed as: Y = − 2.3 (± 0.3) + 0.953 (± 0.06)X, (R² = 0.99, n = 49) where Y is PD excretion (mmol/day) and X is the PDC index. The PDC index was calculated as the molar concentration ratio of PD to creatinine times the metabolic body weight (kg). The corresponding microbial-N values to PDC index of groups I, II and III in developed banding system are 15–25 g/day. Experimentally estimated DOMI was 2.21 ± 0.15 kg/day. Estimated DOMI of groups I, II, and III were 2.8 ± 0.6, 2.6 ± 0.7 and 2.7 ± 0.7 kg/day, respectively. In conclusion, the PDC index in spot urine samples could be used under similar farm condition as an indicator of microbial protein supply in YK-C cattle. Estimated DOMI from PDC index in spot urine samples under defined field conditions may help the development of feeding strategies for YK-C cattle held by small holders.     

Follicular fluid concentration of transforming growth factor-beta1 is negatively correlated with estradiol and follicle size at the early stage of development of the first-wave cohort of bovine ovarian follicles

The objectives of this study were to characterize the relationship between estradiol and transforming growth factor-β1(TGF-β1) concentrations in follicular fluid of growing bovine ovarian follicles, and to examine the effect of TGF-β1 on FSH-stimulated estradiol secretion in cultured bovine granulosa cells. Follicular fluid was collected from individual follicles >5 mm in diameter by ultrasound-guided transvaginal puncture (n = 12 heifers). Follicles were sampled at four different stages of development of the first post-ovulatory wave during selection of the single dominant follicle. Estradiol, progesterone and total TGF-β1 were measured in follicular fluid of the three or four largest follicles sampled when the largest follicle (F1) had reached either 6.5, 7.5, 8.5 or 9.5 ± 0.5 mm stage of development. There was a significant negative relationship between follicular fluid TGF-β1 and estradiol concentrations (R² = 0.44; p < 0.002), and between TGF-β1 concentrations and follicle diameter (R² = 0.23; p < 0.01) in cohort follicles at the 6.5 mm stage, but not at any later stage of development of the follicle wave. There was no correlation between progesterone and TGF-β1 concentrations at any stage. To assess the causal relationship between TGF-β1 and estradiol, granulosa cells from follicles measuring 2–5 mm at dissection were placed in serum-free culture. TGF-β1 caused a dose-dependent decrease in FSH-stimulated estradiol secretion (P < 0.001). These findings suggest that TGF-β1 has an inhibitory effect on estradiol secretion in FSH-stimulated follicles and that a reduction in TGF-β1 inhibition may be part of the mechanism of selection of a single dominant follicle.     

Correlation between carcass conformation and fat cover degree, and muscle fatty acid profile of yearling bulls depending on breed and mh-genotype

The objective was to study the relationships between the actual European beef carcass classification scale, which classifies carcasses with regard to conformation and degree of fat cover scores, and muscle fat quality, depending on breed and mh-genotype. For this purpose samples from 100 yearling bulls from “Asturiana de los Valles” (24 AV(mh/mh), 26 AV(mh/+), 25 AV (+/+)) and “Asturiana de la Montaña” (25 AM) were analysed. The results of the study showed that breed or genotype affect carcass measurement scores and muscle fatty acid profile through its important effect on animal overall fatness. Homozygous double-muscled animals produced carcasses with high conformation and low intramuscular (IM) fat content. While early-maturing and rustic AM animals produced low carcass yield and high IM fat content. The other genotypes (mh/+, +/+) showed, in general, intermediate characteristics. Referring to correlations, carcass conformation was negatively related to saturated (SFA) (r = − 0.69, P < 0.001) and monounsaturated fatty acid (MUFA) (r = − 0.69, P < 0.001) groups, and positively to polyunsaturated (PUFA) (r = 0.72), n-6 (r = 0.72), n-3 (r = 0.71) and unsaturated fatty acid (UFA) (r = 0.69) groups, being all of them significant (P < 0.001). However, carcass degree of fat cover was positively related to SFA (r = 0.53, P < 0.001) and MUFA (r = 0.62, P < 0.001), and negatively to PUFA (r = − 0.61), n-6 (r = − 0.60), n-3 (r = − 0.62) and UFA (r = − 0.53) groups, being all of them significant. Moreover, simple and low-cost prediction equations were calculated for a rapid and sufficiently accurate fatty acid group (SFA, MUFA, PUFA, n-6, n-3, UFA) estimation (R² > 0.46, P < 0.001). In general, meat obtained from double-muscled animals display a more appropriate IM fatty acid profile from the nutritional point of view according to actual recommendations, but it could happen the disability of these lean animals to deposit sufficient IM fat to ensure consumer overall liking or acceptability.     

Nutritional value of timothy haylage in Icelandic horses

Four mature Icelandic geldings were used in a balance trial to investigate the effect of stage of maturity of timothy (Pleum pratence L.) haylage fed at maintenance level on coefficients of total tract apparent digestibility (CTTAD), and nitrogen and energy metabolism in a 4 × 4 change-over arrangement of treatments. The content of fibre increased and crude protein content decreased with advancing stage of maturity. Very high CTTAD values were found for DM, OM, CP, CF, NDF and ADF in the first two cuts. Overall, there was a negative relationship between stage of maturity (p < 0.05) and the CTTAD of all measured dietary components. Nitrogen (N) intake, N losses in urine and N balance were affected (p < 0.05) by stage of maturity, while the N losses in the faeces were unaffected. There was a strong correlation (r² = 0.95) between N balance and water intake. Gross energy intake and losses in urine (as % of digestible energy intake) were unaffected by stage of maturity, while the energy balance was affected (p < 0.05). The digestible energy content of the timothy haylage studied ranged from 14.1 to 9.0 MJ/kg DM.

In conclusion, early-cut timothy haylage (stem elongation to flowering) has the energy content required to form the basis of diets for high-performing horses. Late-cut timothy haylage (seeding to late seeding), on the other hand, can be used to fulfil the energy and protein needs of maintenance-fed Icelandic horses.     

Transmission parameters of Mycobacterium avium subspecies paratuberculosis infections in a dairy herd going through a control program

A Johne's disease control program, including stringent management practices and a test-and-cull program (whole-herd fecal-samples taken twice a year), was implemented on a medium-sized Pennsylvania dairy farm that was suffering losses from clinical Johne's disease. The data that emerged from the control program, combined with birthdates, culling dates, lactation information and pedigrees, yielded an extensive longitudinal dataset. The dataset was processed through SAS 9.1 for statistical analysis; herd-level disease dynamics and dam-to-daughter transmission parameters were calculated. After the implementation of the program in 1984, prevalence dropped dramatically from 60% to less than 20% in 1989. After an apparent prevalence peak (25%) in 1991 due to improved test sensitivity, prevalence maintained a plateau of 10% from 1996 to 2000. After the implementation of the program, 9.5% of the offspring from test-negative dams and 26.8% of the offspring from known-infected dams became infected with Mycobacterium avium subspecies paratuberculosis (Map) (χ² = 14.7; p = 0.0001). Calves born shortly following the calving of an infected dam and calves growing up with a future high shedder were more likely to be infected compared to calves without this risk profile. It was concluded that, after the implementation of the control program, the most important causes of infections of susceptible calves were their own dams or infected animals which had calved recently.     

Association between butyrate and short-chain fatty acid concentrations in gut contents and faeces in weaning piglets

The concentration and composition of short-chain fatty acids (SCFA) in gastrointestinal and faecal samples were studied in weaning pigs fed different amounts and composition dietary fibre (DF). In Trial 1 a total of 50 castrated piglets were fed five experimental diets with varying contents of citrus pectin (soluble fibre) and barley hulls (insoluble fibre) and gastrointestinal contents were collected at euthanasia 9 days after weaning. In Trial 2, 120 pair-wise penned piglets were allocated to the same experimental diets as in Trial 1 (24 piglets per treatment), and fresh faecal samples were collected 5 and 32 days after weaning.

There was no difference in the concentrations of SCFA caused by dietary treatments, but across treatments there was a correlation between concentration of SCFA and the proportion of butyrate. The correlation was lowest in the caecum (r² = 0.22, P = 0.0007) and highest in the distal colon (r² = 0.45, P = 0.0001). In faeces there was no relationship 5 days after weaning (r² = 0.004. P = 0.64) but a correlation of r² = 0.25 (P = 0.0001) 32 days after weaning. The results suggest that adaptive changes and differences between piglets in fermentative capacity immediately after weaning are associated not only with a higher concentration of SCFA but also a changed fermentation profile.     

Effects of a second mutant allele (V199I) at the PRKAG3 (RN) locus on carcass composition in pigs

The effect of a second mutant allele (V199I, here denoted rn*) at the PRKAG3 (RN) locus on carcass composition was determined in 334 pigs, entire males and females, from crosses between Swedish Hampshire (H) and Finnish Landrace (L) (H × LH; LH × H; LH × LH). Pigs were classified according to DNA test into the following PRKAG3 genotypes: RN⁻/RN⁻ (23%), RN⁻/rn⁺ (24%), RN⁻/rn* (33%), rn⁺/rn⁺ (8%), rn⁺/rn* (9%) and rn*/rn* (2%). The pigs were slaughtered at a commercial slaughterhouse and assessed 24 h postmortem. Right sides were fabricated into primary wholesale cuts, then further processed into defatted hams and loins, and a subset of hams (n = 122) was dissected into the five major individual muscles. The genotype frequencies for the subsample were RN⁻/RN⁻ (27%), RN⁻/rn⁺ (20%), RN⁻/rn* (35%), rn⁺/rn⁺ (9%), rn⁺/rn* (8%) and rn*/rn* (1%). Weights were recorded for meat and bone in ham and loin, fat in ham, back and shoulder and the individual dissected muscles. The genotype effect was significant (P < 0.05) for estimated lean meat content and the proportions of meat and bone and fat in ham and loin (of carcass weight). Also, the content of meat and bone in ham and loin, in proportion of whole ham and loin, respectively, differed significantly (P < 0.01) between genotypes. Estimated lean meat content was highest for RN⁻/RN⁻ (63.0%) and RN⁻/rn⁺ (63.1%) and lowest in the combined group rn*/⁻ (rn⁺/rn* and rn*/rn*, 61.7%); RN⁻/rn* (62.5%) and rn⁺/rn⁺(62.1%) were intermediate. The same results were found for meat and bone in ham and loin, as a proportion of whole ham and loin, respectively. RN⁻/RN⁻ and RN⁻/rn⁺ did not differ in any trait; however, they produced carcasses with the lowest proportions of fat within loin and the major wholesale cuts (ham, loin and shoulder). The carcass percentage of meat and bone in ham was higher in the three RN⁻/ genotypes (RN⁻/RN⁻, RN⁻/rn⁺ and RN⁻/rn*, P < 0.05) than in the rn*/⁻ group, whereas rn⁺/rn⁺ did not (P > 0.05) differ from any of the other genotypes. RN⁻/rn⁺ and RN⁻/rn* had higher (P < 0.05) proportion of meat and bone in loin compared to the rn*/⁻ group. We conclude that the second mutant allele found at the PRKAG3 (RN) locus, rn*, decreased the lean meat content compared with the two other alleles (RN⁻, rn⁺). The RN⁻/RN⁻ and RN⁻/rn⁺ genotypes were leanest, followed by RN⁻/rn* and rn⁺/rn⁺, and rn⁺/rn* and rn*/rn* were the fattest.     

Canine echinococcosis in northwest Libya: assessment of coproantigen ELISA, and a survey of infection with analysis of risk-factors

In order to determine the prevalence and risk factors for canine echinococcosis in different endemic localities in the Tripoli area of northwest Libya, stray dogs were examined post-mortem, and owned dogs screened for Echinococcus granulosus infection using a standardised genus specific coproantigen ELISA. The prevalence of E. granulosus infection at necropsy in stray-dogs was 25.8% (15/58, 95% CI 15.3–39.0%), and 21.6% (72/334, 95% CI 17.3–26.4%) of owned dogs tested were positive by coproantigen ELISA. Sheepdogs appeared to have a significantly higher copro-positive prevalence (19/19 positive, p = 0.003), compared to 23.6% of other dog classes (e.g. 52/220 guard dogs and household pets). Worm burdens in necropsied dogs ranged from 29 to 2900 (mean 1064) and were positively correlated to coproantigen ELISA OD values (r_s = 0.87, p < 0.001), but negatively correlated with dog age (r_s = −0.69, p = 0.001). Dog age was a significant factor in copro-prevalence as there was an increasing coproantigen-positive tendency in younger dogs (≤5 years, p = 0.04). A total of 45/132 (34%, 95% CI 25.9–42.1%) of farms/homestead had at least one dog that was coproantigen positive. Overall copro-prevalence in dogs by locality varied, with Alkhums (Leptis-Magna) district having the highest copro-prevalence at 38.7% (24/62, 95% CI 26.6–50.8%) (p = 0.001). Coproantigen testing of a cohort of owned dogs before and approximately 15 months after praziquantel treatment showed a significant decrease in the coproantigen positive rate from 21.6% (72/334) to 9% (21/233) post-treatment. The overall E. granulosus coproantigen positive rate (‘re-infection rate’) within the same cohort of dogs was 22 % (10/45) by 15 months post-treatment. Significant risk factors for a copro-positive owned dog were associated with non-restraint of dogs, and owners that did not de-worm their dogs. Home slaughtering of livestock and lack of knowledge about E. granulosus transmission were also significant risk factors for a canine coproantigen positive result.     

Therapeutic and persistent efficacy of moxidectin 1% nonaqueous injectable formulation against natural and experimentally induced lung and gastrointestinal nematodes in cattle

Four controlled trials were conducted to evaluate the therapeutic and persistent efficacy of a new moxidectin formulation (moxidectin 1% nonaqueous injectable) against nematode parasites in cattle. This injectable moxidectin formulation, given as a single subcutaneous injection at a dose rate of 0.02 ml/kg BW to provide 0.2 mg moxidectin/kg BW, was highly efficacious (>90–100%) against larval and/or adult stages of many species of nematodes in cattle including, Dictyocaulus viviparus, Ostertagia spp., Trichostrongylus axei, Haemonchus placei, Trichostrongylus colubriformis, Cooperia spp., Nematodirus helvetianus, Strongyloides papillosus, Oesophagostomum radiatum and Trichuris spp. This formulation had persistent efficacy of >90% against D. viviparus for at least 6 weeks post-treatment, H. placei and Oe. radiatum for 5 weeks post-treatment, and Ostertagia spp. and T. axei for 2 weeks post-treatment.     

Comparative evaluation of two emigration/sedimentation techniques for the recovery of dictyocaulid and protostrongylid larvae from faeces

A comparison between the performance of a flask and a funnel method in recovering dictyocaulid and protostrongylid larvae from faeces revealed the clear superiority of the former. On an average, 137% (p < 0.01) more Dictyocaulus viviparus, 175% (p < 0.05) more Muellerius capillaris and 1709% (p < 0.01) more Elaphostrongylus cervi larvae were recovered from samples processed by flask rather than funnel. Attempts to further improve the flask method by substituting cloth stockinette for paper tissue, tended to result in the recovery of more faecal debris but no more larvae. In addition to its greater sensitivity, it is suggested that the flask method offers advantages over the funnel system both in terms of time-saving and in lessening the likelihood of cross-contamination.     

Variation in seed protein digestion of different pea (Pisum sativum L.) genotypes by cecectomized broiler chickens: 2. Relation between in vivo protein digestibility and pea seed characteristics, and identification of resistant pea polypeptides

Eight pea genotypes characterized for their major protein fractions were used to investigate the effect of seed protein composition variability on protein digestibility in poultry. These genotypes of various pea types, were also variable in other seed components. They showed variations in their carbohydrate (insoluble fibre compounds, soluble fibre, soluble carbohydrates) and trypsin inhibitor (TI) contents. To exclude the effect of tannins and of particle size, the seeds were dehulled and micro-ground. They were incorporated as the only protein source in isoproteinaceous diets with similar metabolisable energy content and fed to cecectomized chickens. The average amino acid digestibility (apparent and true) and endogenous amino acid excretion were related with pea diet characteristics (protein composition, carbohydrate composition and TI activity). This allowed to precise which of the diet characteristics affect protein digestibility and endogenous excretion. Average apparent digestibility of amino acids was negatively correlated with insoluble fibre components (R = − 0.71 to − 0.72; p < 0.05) and TI activity (R = − 0.93; p < 0.001). Average endogenous losses of amino acids were positively correlated with soluble carbohydrate content (R = 0.77; p < 0.05) and TI activity (R = 0.84; p < 0.01). Average true digestibility of amino acids was positively correlated with the PA2 albumin level (R = 0.71; p < 0.05), and negatively with the legumin level (R = − 0.72; p < 0.05). Resistant peptides extracted from chicken excreta were analysed through electrophoresis and identified by immunodetection. Intensity of detected resistant peptides showed variation among genotypes. However, for the 8 pea genotypes, the pea proteins, which persisted at the end of the digestive tract, were mainly albumin PA1b and lectin. Other minor peptides were also detected: vicilin, albumin PA2 and legumin peptides which migrated at the same level as β-subunits.     

A descriptive survey of lesions from cull sows harvested at two Midwestern U.S. facilities

Physical and reproductive conditions of cull sows (3158) from two U.S. Midwestern harvest plants were assessed. Body condition, feet, shoulders, teeth, lungs, and reproductive tracts were visually evaluated for gross lesions on harvested sows. PROC FREQ (SAS, Cary, NC) was used to calculate the frequency of each binary trait event. Pearson chi-square tests were used to test the alternative hypothesis that a linear association existed between binary traits and body condition score (BCS). The most common foot lesions observed were rear (n = 2064, 67.5%) and front (n = 1024, 32.9%) heel lesions. Cracked hooves were found on the front feet of 703 (22.6%) and rear feet of 552 (18.1%) sows. Rear digital overgrowth was observed in 644 (21.1%) sows. The most common reproductive gross lesion observed among harvested cull sows was acyclic ovaries (n = 277, 9.0%). Presence of acyclic ovaries increased (p < 0.01) as BCS decreased. Cystic ovaries were found in 192 (6.3%) sows, which increased (p < 0.01) as BCS increased. Pneumonia was observed in 298 (9.7%) sows, and increased in frequency as BCS decreased (p < 0.01). The most frequently observed shoulder lesion among harvested cull sows was shoulder abrasions (n = 394, 12.5%). The presence of shoulder abrasions increased (p < 0.01) as BCS decreased. The prevalence of reproductive lesions detected in the present study was less than the reported percentage of sows culled for reproductive failure from previous studies based on record keeping summaries.     

Studies on vertical transmission of Trichinella spp. in experimentally infected ferrets (Mustela putorius furo), foxes (Vulpes vulpes), pigs, guinea pigs and mice

Vertical transmission of Trichinella spiralis was evaluated in ferrets (n = 21), foxes (n = 11), pigs (n = 12), guinea pigs (n = 16), and mice (n = 41). The placental barrier to be crossed by migratory Trichinella larvae varies structurally in different animal species. Ferrets and foxes have an endotheliochorial placenta structure, guinea pigs and mice a haemochorial, and pigs an epitheliochorial placenta. The non-encapsulating Trichinella pseudospiralis larvae have an extended muscle migration prior to entering a muscle cell. To evaluate if T. pseudospiralis was more likely to be transmitted to offspring, an additional group of foxes (n = 11) infected with T. pseudospiralis was included. Two different dose levels were used for ferrets, pigs, guinea pigs, and mice. In pigs and guinea pigs, infection was given at different times of the gestation period. Vertical transmission, measured as recovery of muscle larvae in the offspring, was demonstrated in both ferrets groups, in all four guinea pig groups, and in the high dose mouse group, but not in any fox or pig groups.     

Effect of dietary iodine on growth and iodine status of growing fattening bulls

The aim of the present study was to assess the influence of different levels of iodine supplementation on animal growth and the iodine content of food from beef cattle. In a dose–response experiment with 34 growing fattening bulls of the “German Holstein” breed, in the range from 223 to 550 kg body weight, three iodine dosages were tested. The animals were fed a corn silage/concentrate ration. Iodine concentration in the diet amounted to 0.79 (Group 1), 3.52 (Group 2) and 8.31(Group 3) mg I per kg dry matter (DM). After slaughtering, I was determined in blood, serum, plasma, thyroid, liver, kidneys and meat (M. longissimus dorsi, M. glutaeus medius) by ICP-MS. I-supplementation did not significantly influence DM intake, daily weight gain (1453 (1), 1419 (2) and 1343 (3) g; p > 0.05) or slaughtering performance, but the weight of the thyroid gland increased significantly with the highest I dosage (32 (1), 26 (2) and 42 (3) g animal^− 1, p < 0.05). I-supplementation significantly increased I-concentration in muscle, liver, kidney and thyroid gland (p < 0.05). The contribution of beef food to I-intake of humans is relatively low, therefore there is no need to reduce the EU-upper limit (10 mg kg^− 1 feed) for growing fattening cattle from the view of consumer safety. In view of animal health and performance more dose–response studies seem to be necessary.