Effects of housing system (outdoor vs cages) and age of laying hens on egg characteristics

1. Effects of two housing systems (cages vs outdoor) on external and internal egg characteristics were investigated. 2. In total 785 eggs from three different lines in cages and 268 eggs from outdoor-housed layers were examined for egg weight, albumen, yolk and shell content, albumen height and pH, and albumen and yolk dry matter content. 3. Interactions between layer age and housing systems were found for egg weight, eggshell content, albumen height, albumen pH, and dry matter content of the albumen and yolk. This was mainly due to the greater variation with age in the outdoor layers, compared to the caged layers. 4. Irrespective of age eggs from outdoor layers were relatively broader than eggs from the caged layers. Yolk colour was considerably darker in the outdoor group (11.0 vs 9.3). 5. We concluded that it is more difficult to maintain constant external and internal egg quality in an outdoor housing system than in a battery cage system. Factors that determine the greater fluctuations in internal egg quality need to be investigated.     

Mixed infection by Libyostrongylus douglassii and L. dentatus (Nematoda: Trichostrongylidae) in Struthio camelus (Ratites: Struthioniformes) from Brazil with further morphological characterization of adults

The genus Libyostrongylus includes three species, L. douglassii, L. dentatus and L. magnus that occur as parasites in the proventriculus of Struthio camelus. We confirmed a mixed infection by L. douglassii and L. dentatus in farmed ostriches from the southeast of Brazil for the first time, and provided new information on some morphological characters that differentiate these species. Adult nematodes collected from the proventriculus of ostriches were observed by light and scanning electron microscopy. Morphologic characterization and morphometric analysis of the nematodes enabled the distinction of both species and corroborated results of prior studies. Specimens of L. dentatus have a buccal capsule with a prominent esophageal tooth. Furthermore, males and females of L. dentatus were larger (4954 and 9347 microm) than those of L. douglassii (3411 and 4229 microm), but measurements for most characters in both species were smaller then those previously reported. Besides, the cephalic structure based on scanning electron microscopy differs, and L. dentatus has thick lips with round papillae, whereas L. douglassii has fine lips with lengthened papillae. The confirmation of both species in South America strongly suggests that the mixed infection may be common in farmed ostriches.     

Leptospirosis is strongly associated to estrus repetition on cattle

Tropical Animal Health and Production - Although prevalent, the exact impact of infectious diseases on reproductive failures remains to be determined. Among them, leptospirosis has commonly been...     

Eradication of rock pigeons,Columba livia,from the Galápagos Islands

Alien species can negatively affect global biodiversity, especially on islands. Significant advances in methods for eradicating mammals from islands have been achieved. In contrast, development of methods for eradicating birds from islands has lagged and few islands have had alien birds successfully eradicated. We report on a 7 year campaign to remove rock pigeons from the Galapagos Islands. To date this is the largest successful eradication of an alien bird from an island system and the only eradication of rock pigeons from an island. Multiple methods were tested and used, including alpha-chloralose, however, shooting with a high-powered air rifle was the most efficient removal technique. Incorporating the support of the community and local agencies into the campaign was critical to the success of the project.     

Effects of Dextrose Plus Lactose in the Sows Diet on Subsequent Reproductive Performance and within Litter Birth Weight Variation

Effects of dextrose plus lactose in sow’s feed were tested on subsequent reproductive performance and within litter birth weight variation. During the last week of gestation and lactation, sows were either fed a commercial lactation diet (Control: C), or an isocaloric diet containing 25 g/kg dextrose plus 25 g/kg lactose (Treatment: T). In the subsequent weaning‐to‐oestrus interval (WEI), all sows received the same amount of a commercial feed, but T sows were supplemented with 150 g dextrose plus 150 g lactose per day. Weight and backfat changes were recorded as well as litter characteristics during the treatment period and the subsequent parity. No significant effect of treatment was found on the subsequent reproductive performance, including the number of piglets born, although the number of live born piglets was 0.51 larger (p = 0.31) and weight of the live born piglets was 84 g higher in the T sows (p = 0.07) than in the C sows. When sows were categorized in sows with 12 or less and more than 12 total born piglets in the previous litter, treatment of sows with dextrose plus lactose resulted for the group with 12 or less piglets in a strong increase in subsequent total born piglets (13.97), whereas in the untreated sows the subsequent litter size was 11.89. In the group with more than 12 total born piglets, no effect of treatment was found (interaction between previous litter size and treatment p = 0.03). The within litter variation in birth weight in the subsequent litter was numerically lower in the T sows. We concluded that the use of dextrose and lactose during lactation and WEI seems to enhance litter size in sows with low previous litter size and seems to have the potential to reduce the within litter variation in birth weight.     

Platelet aggregation studies in acute experimental canine ehrlichiosis

BACKGROUND: Thrombocytopenia is the most common and consistent hematologic finding in patients with canine monocytic ehrlichiosis. Dogs that recover from the severe thrombocytopenia still show bleeding tendencies, which suggest that platelet dysfunction is present. OBJECTIVES: The purpose of this study was to determine the occurrence and duration of platelet dysfunction in dogs with ehrlichiosis and to assess whether dysfunction is related to thrombocytopenia. METHODS: Ten adult male and female mongrel dogs were used in the study; 7 were inoculated intravenously with whole blood containing Ehrlichia canis, and 3 were used as controls. Platelet aggregation (with collagen/epinephrine and adenosine diphosphate (ADP)/epinephrine) and platelet counts were evaluated weekly for 112 days. RESULTS: The infected group showed a decrease in platelet aggregation response to collagen/epinephrine and ADP/epinephrine on days 7, 14, 21, 28, and 35 (P <.05). Thrombocytopenia was observed in all infected animals from day 7 to 35 postinfection (P <.05). CONCLUSIONS: The tendency of dogs infected with E canis to bleed may be related not only to thrombocytopenia but also to platelet dysfunction associated with the disease.     

Occurrence of Libyostrongylus sp. (Nematoda) in ostriches (Struthio camelus Linnaeus, 1758) from the north region of the state of Rio de Janeiro, Brazil

Domestic production of ostrich in Brazil started in the beginning of the last decade, but its sanitary state has not been reported. Libyostrongylus sp. is an ostrich specific nematode whose parasitism can severely affect the birds. Thus, Libyostrongylus spp. larvae were identified in commercial ostriches in the north region of the state of Rio de Janeiro, Brazil. The EPG was determined and fecal cultivation was performed. The eggs presented typical characteristics of strongylid and were present in five out of six farms. The mean EPG varied from 22 to 2395 and Libyostrongylus spp. prevalence was from 0 to 100%, with adult birds more infected. Two types of infective larvae with tail finishing in a tipped spiny knob were distinguished. The first had a mean length of 848 microm (710-1010) with a long sheath tail of about 66 microm (52-112). The other had a mean length of 826 microm (620-940) with a short, more abruptly ending sheath tail of 32 microm (22-40) and a less rounded cephalic end. The differences between these larvae suggest two Libyostrongylus species.     

Strength and stiffness capacity utilisation of timber members in roof truss structures

The main objective of this study was to determine which property, of the six strength and stiffness properties used in structural timber design, was the most influential in the design of nail-plated roof trusses. Thirty recently completed nail-plated roof truss designs were randomly selected from three roof truss manufacturing plants and a total of 8 758 individual truss members were analysed for bending stress, shear stress parallel to grain, tensile stress parallel to grain, compression stress parallel to grain and deflection. The mean strength and stiffness capacity utilised of all the different design properties was well below 50% for all of the different dimension classes. Of all the individual strength properties, the mean bending strength capacity utilised per member was found to be the highest. The results of this study can be used for decision support related to wood property evaluation through? out the structural lumber value chain where roof truss members are the end products.     

Embryonic development in the ostrich (Struthio camelus) during the first 7 days of artificial incubation

1. Early development of ostrich embryos was investigated in relation to time of egg collection and genotype.

2. A total of 321 ostrich eggs were collected during the 2008 and 2009 breeding seasons and the development of the embryo for up to the first 168 h of incubation was described and analysed. A sample of the incubated eggs was weighed and opened daily to investigate developmental changes.

3. In fresh eggs, the blastoderm contained a round, translucent dark area pellucida (AP) in the centre, with a surrounding thin white ring, likely to be the beginning of the area opaca (AO). Fresh eggs were considered infertile if the blastoderm was absent and instead numerous white droplets were present surrounded by vacuoles.

4. The average blastoderm area of a fresh fertile egg was 15.8 mm², increasing to 143.3 mm² after 2 d of incubation. By 72 h of incubation the area vasculosa (AV) was discernible in the posterior half of the blastoderm.

5. At 48 h of incubation the blastoderm area in eggs from the South African Black genotype (SAB) × Zimbabwean Blue genotype (ZB) crosses (104.5 ± 18.6 mm²) was lower than the pure SAB (141.0 ± 10.5 mm²), ZB (161.7 ± 13.5 mm²) and ZB × SAB crosses (166.1 ± 14.2 mm²).

6. Embryo length was 5.01 mm after 72 h of incubation and 14.5 mm after 168 h of incubation. At 168 h of incubation AV lengths for both ZB × SAB (53.2 mm) and SAB × ZB crosses (54.1 mm) were longer than in embryos from the pure breeds.

7. Results from this study can be put to practical use when determining whether eggs are infertile or fertile and also in investigating the age of early embryonic mortalities.