Intake,digestibility and metabolism in sheep fed with increasing levels of spineless cactus (Nopalea cochenillifera Salm-Dyck)

Tropical Animal Health and Production - The objective of this study was to evaluate the effect of the substitution of Tifton 85 hay (Cynodon spp.) with spineless cactus (Nopalea cochenillifera) on...     

OC13Induction of Parturition in Canary Goats with Luprostiol

Twenty-two pregnant goats of the Canarian breed were administered 10 mg of the prostaglandin analogue luprostiol intramuscular (IM) on day 145 of pregnancy; seventeen pregnant goats were injected IM with saline solution the same day. Twenty hours after luprostiol application, goats were continuously observed in order to record the following parameters: parturition, dystocia incidence, placental delivery and live births. Parturition was successfully induced in all goats; the mean interval to parturition (first kid delivery) was of 32.9 ± 1.0 (SEM) hours (h) and the range varied from 21 to 41 h; in addition, no significant differences (p > 0.1) were detected between nuliparous and multiparous goats (31.3 ± 1.3 h and 34.7 ± 1.2 h, respectively). In the control group, the interval from saline injection to parturition was 75.9 ± 12.5 h (mean ± SEM), showing a range between 34 and 138 h. All the goats expelled the fetal membranes in the first 6 h after the induced or natural parturition. The incidence of dystocia due to fetal maldisposition was not significantly different between induced and control goats (9.0% and 11.8%, respectively). In addition, the percentage of live kids was practically similar between both groups (90.7% and 88.0%, induced vs control goats). This study confirms the effectiveness of the luprostiol to induce the parturition in goats, showing a narrow range (30–37 h) in most of the induced females (86.3%; 19/22 goats). The administration of prostaglandin analogue is a basic tool to plan kidding, allowing a effective concentration of effort and resources at the time of parturition.     

Tifton hay, soybean hulls, and whole cottonseed as fiber source in spineless cactus diets for sheep

The objective of this paper was to evaluate the effect of three different sources of fiber (tifton hay, soybean hulls, and whole cottonseed) in spineless cactus diets for sheep in the semiarid region of northeastern Brazil. Twenty-one sheep in finishing phase with indeterminate breed, non-castrated, and with initial weight of 18.90?±?1.07 kg were randomly distributed to individual stalls where they were confined for the duration of the experiment. The intakes of dry and organic matter, total carbohydrates, and total digestive nutrients were not influenced (P?>?0.10) by the different fiber sources (1.10, 0.97, 0.73, and 0.80 kg/day, respectively). However, sheep which received the whole cottonseed diet were characterized by a lower (P?<?0.10) intake of crude protein and neutral detergent fiber and greater (P?<?0.10) intake of ether extract (0.11, 0.29, and 0.048 kg/day, respectively). The different sources of fiber resulted in similar times spent feeding (P?>?0.10), although the rumination time was greater for tifton hay (P?<?0.10) (429.05 min/day). The digestibility coefficient of dry and organic matter differed between the treatments (P?<?0.10), with the soybean hull diet showing a higher level of digestion (83.23 and 86.72 %, respectively). The whole cottonseed diet gave the smallest digestibility coefficient of crude protein (68.95 %) and greatest for ether extract (85.94 %). The daily weight gain of animals fed on whole cottonseed was significantly lower (P?<?0.10). On the basis of these findings, we recommend the use of tifton hay or soybean hulls as important additional source of fiber in forage spineless cactus diets for sheep in finishing phase.     

Influence of sexual stimulation and the administration of human chorionic gonadotrophin on plasma testosterone levels in dogs

The influence of sexual stimulation and human chorionic gonadotrophin (hCG) administration on plasma testosterone concentrations was assessed in five male Beagles. Each dog was exposed to three experimental treatments: C treatment (Control, no stimulation), hCG treatment (dogs were SC injected with 1000 IU of hCG) and sexually stimulated (SS) treatment where semen was collected from the males. All dogs were exposed to all treatments, one per week for three consecutive weeks, with a 1 week of rest between treatments. Blood samples were taken with the same time intervals (0, 10, 30, 60 and 120 min) relative to treatments. Plasma testosterone concentrations were determined with a solid-phase I(125) radioimmunoassay. In the control treatment, the testosterone plasma levels did not show significant changes throughout the tested period (mean values ranging between 2.8 and 4.7 ng/ml); the hCG group presented a significant increase (p < 0.05) in plasma testosterone levels 30 min after hCG administration and had the highest value (8.7 ng/ml) at 120 min post-hCG. Finally, the SS group revealed a slight reduction in testosterone concentration immediately after ejaculation, but the values remained nearly unaltered until 120 min after semen collection. When the groups were compared, the hCG group showed higher plasma testosterone values (p < 0.05) than did the C and SS groups, starting at 30 min and continuing until the end of sampling. This study demonstrates that sexual stimulation associated with semen collection does not produce transitory modifications in plasma testosterone concentrations.     

Evaluation of systems for reducing the transmission of Porcine reproductive and respiratory syndrome virus by aerosol

The purpose of this study was to compare 3 methods for the reduction of aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV): high-efficiency particulate air (HEPA) filtration, low-cost filtration, and ultraviolet light (UV) irradiation. The HEPA-filtration system involved a pre-filter screen, a bag filter (EU8 rating), and a HEPA filter (EU13 rating). The low-cost-filtration system contained mosquito netting (pre-filter), a fiberglass furnace filter, and an electrostatic furnace filter. For UV irradiation, a lamp emitted UVC radiation at 253.7 nm. No form of intervention was used in the control group. The experimental facilities consisted of 2 chambers connected by a 1.3-m-long duct. Recipient pigs, housed in chamber 2, were exposed to artificial aerosols created by a mechanically operated mister containing modified live PRRSV vaccine located in chamber 1. Aerosol transmission of PRRSV occurred in 9 of the 10 control replicates, 8 of the 10 UVC-irradiation replicates, 4 of the 10 low-cost-filtration replicates, and 0 of the 10 HEPA-filtration replicates. When compared with no intervention, HEPA filtration and low-cost filtration significantly reduced PRRSV transmission (P < 0.0005 and = 0.0286, respectively), whereas UV irradiation had no effect (P = 0.5). However, low-cost filtration and UV irradiation were significantly less effective (P = 0.043 and P < 0.0005, respectively) than HEPA filtration. In conclusion, under the conditions of this study, HEPA filtration was significantly more effective at reducing aerosol transmission of PRRSV than the other methods evaluated.     

Effects of bovine leukemia virus infection on milk neutrophil function and the milk lymphocyte profile

The effects of bovine leukemia virus (BLV) on the immune response have been extensively investigated; however, its effects on mammary gland immunity are only speculative. Although BLV has a tropism for B cells, it can affect both adaptive and innate immunities because these systems share many effector mechanisms. This scenario is the basis of this investigation of the effects of BLV on mammary gland immunity, which is largely dependent upon neutrophilic functions. Thus, the present study sought to examine neutrophilic functions and the lymphocyte profile in the milk of naturally BLV-infected cows. The viability of the milk neutrophils and the percentage of milk neutrophils that produced reactive oxygen species (ROS) or phagocytosed Staphylococcus aureus were similar between BLV-infected and BLV-uninfected dairy cows. Furthermore, the expression of CD62L and CD11b by the milk neutrophils and the percentage of milk neutrophils (CH138⁺ cells) that were obtained from the udder quarters of the BLV-infected cows were not altered. Conversely, the median fluorescence intensity (MFI) representing intracellular ROS production and the phagocytosis of S. aureus, the expression of CD44 by the milk neutrophils and the percentage of apoptotic B cells were lower in the milk cells from BLV-infected dairy cows, particularly those from animals with persistent lymphocytosis (PL). The lymphocyte subsets were not different among the groups, with the exception of the percentage of CD5⁻/CD11b⁻ B cells, which was higher in the milk cells from BLV-infected cows, particularly those with PL. Thus, the present study provides novel insight into the implications of BLV infection for mammary gland immunity.     

Characterization of an ecto-5'-nucleotidase activity present on the cell surface of Tritrichomonas foetus

Tritrichomonas foetus is the causative agent of sexually transmitted trichomoniasis in cattle. In females, the infection can be associated with infertility, vaginitis, endometritis, abortion or pyometra, leading to significant economic losses in cattle raising. T. foetus is devoid of the ability to synthesize purine nucleotides de novo, depending instead on salvaging purines from the host environment. Ecto-5'-nucleotidase catalyzes the final step of extracellular nucleotide degradation, the hydrolysis of nucleoside 5'-monophosphates to the corresponding nucleosides and Pi. In this work we show that living, intact cells of T. foetus were able to hydrolyze 5'AMP at a rate of 12.57 ± 1.23 nmol Pi × h(-1) × 10(-7) cells at pH 7.2 and the 5'AMP hydrolysis is due to a plasma membrane-bound ecto-enzyme activity. The apparent K(m) for 5'AMP was 0.49 ± 0.06 mM. In addition to 5'AMP, the enzyme hydrolyzed all substrate monophosphates tested except 3'AMP. No divalent metals or metal chelators were able to modulate enzyme activity. Phosphatase inhibitors did not have an effect on ecto-5'-nucleotidase activity while ammonium molybdate did inhibit the activity in a dose dependent manner. The presence of adenosine in the culture medium negatively modulated the enzyme. These results indicate the existence of an ecto-5'-nucleotidase that may play a role in the salvage of purines.