Determination of the Genital Tubercle Migration Period in Morada Nova Sheep Foetuses by Ultrasonography

The aim of this study was to determine the period of genital tubercle (GT) migration using ultrasonography in Morada Nova sheep foetuses (n = 117) from natural mating (NM) and frozen embryo transfer (ET) to determine the window when foetal sexing can be determined. The examinations were performed using transrectal ultrasonography with a dual-frequency linear transducer (6.0 and 8.0 MHz) from day 30-54 of pregnancy at 48-h intervals. The period of GT migration of foetuses produced by NM varied from 36 to 46 days of pregnancy, resulting in an average of 39.5 +/- 2.9 days. For foetuses derived from ET, GT migration varied from 42 to 52 days of pregnancy with an average of 48.5 +/- 3.3 days, being possible the GT of foetuses from ET start to migrate 96 h later even if they are of the same gender. Migration of the GT occurred earlier (p < 0.05) in foetuses produced by NM and sexing accuracy for triplet pregnancies (77.8%) was significantly inferior (p < 0.05) to single (100%) and twin (92.9%) pregnancies for foetuses derived by NM. The results allow one to conclude that foetal sexing can be done from the 50th day onwards in foetuses produced by NM and from the 55th day onwards in foetuses derived from ET, and that multiple pregnancies compromise the sexing accuracy by ultrasonography.     

Combined GnRH and PGF2α Application in Cows with Endometritis Puerperalis Treated with Antibiotics

The investigations were carried out on a total of 70 cows with puerperal endometritis. In addition to intrauterine antibiotic treatment, 30 experimental animals were administered 20 μg GnRH analogue, buserelin, between days 10 and 12 post‐partum followed by 500 μg PGF_2α analogue, cloprostenol, 10 days later. Forty control cows were treated only with intrauterine antibiotics. Blood samples for progesterone determination were collected from the tail vein twice weekly until day 70 post‐partum. The first rise in progesterone level above 3.18 nmol/l occurred significantly earlier in the experimental than in control cows (21.6 ± 9.2 versus 27.8 ± 12.3 days; p ≤ 0.05). The duration of the first cycle post‐partum was 15.0 ± 4.3 days in experimental and 19.7 ± 7.3 days in control animals (p ≤ 0.05). However, no significant differences were observed in the occurrence of first oestrus post‐partum. The involution of the uterus was improved after hormone treatment. At day 42 post‐partum, completion of uterine involution was found in 93.3% of hormone‐treated cows and in 82.5% of those treated with antibiotic only (p ≤ 0.05). Clinical recovery was 96.6% in the experimental and 82.5% in the control group (p ≤ 0.05). First service pregnancy rate was significantly better in hormone‐treated than control cows (51.7 versus 36.4%; p ≤ 0.05). Total pregnancy rate and insemination index values were not significantly improved following GnRH and PGF_2α treatment. The average service period was 89.8 ± 21.2 days in cows after hormone treatment, and 112.6 ± 24.5 days in control cows. The difference was statistically significant (p ≤ 0.05). These results indicate, that the sequential GnRH and PGF_2α application in cows with puerperal endometritis positively affected ovarian function and uterine involution, resulting in improved fertility performance.     

The diagnostic value of the cement gland and other abdominal structures in aleyrodid taxonomy

The morphological characters on which the taxonomy of the Aleyrodidae is based are found in the last instar larvae (pupae). Since in many situations only adults are available (as in sticky trap catches), difficulties may arise if specific determination is needed. In fact, the information given by the vasiform structure of adults and the male genitalia is not always conclusive. In the course of the present study, two sources of useful information were found in the female abdomen, namely the morphology of the cement gland and the setal pattern of the gonapophyses. Both structures can easily be examined by light microscopy, with a simple method of preparation. These characters (mainly those concerning the cement gland) have been consistent enough to allow identification of the main whitefly pest species in Portugal. An identification key mostly based on these structures is presented for Aleurothrixus floccosus, Aleyrodes proletella, Bemisia tabaci, Parabemisia myricae, Siphoninus phillyreae, Trialeurodes vaporariorum and Dialeurodes citri (this last not yet found in Portugal).     

Factors affecting formation of methyl nitrite in soils

The formation of CH₃ONO in 11 soils treated with HNO₂ or NaNO₂ in a closed system, was studied by measuring the concentration in the gas space above the soil and by absorbing CH₃ONO in HI. The gaseous concentration of CH₃ONO increased and then decreased following additions of HNO₂ or NaNO₂, and the production of CH₃ONO increased with increasing concentrations of HNO₂ or NaNO₂ added to soils.
The amounts of CH₃ONO trapped in HI were 13.5 to 20.4 times higher than those determined by integrating under the net production curves. The evolved CH₃ONO amounted to 0.4 to 3.5% of added NO₂⁻, and 4.2 to 50% of the gaseous forms of N absorbed by acidic KMnO₄ solution. The CH₃ONO evolved from soils was positively correlated with the methoxy content of the soils, and inversely related to soil pH, with negligible amounts being evolved from alkaline soils. The results show that CH₃ONO is a product of NO₂⁻ decomposition in soils, and indicate that small concentrations of the gas may be produced in N–fertilized soils in which NO₂⁻ accumulates.     

Amino acid availability and protein digestibility of several protein sources for Nile tilapia,Oreochromis niloticus

Apparent amino acid availability coefficients and protein digestibility of four animal products [fish meal (FM), meat and bone meal (MBM), poultry by‐product and feather meal] and four plant protein‐rich products [soybean meal (SBM), cottonseed meal‐28, cottonseed meal‐38 and corn gluten meal (CGM)] were determined for Nile tilapia, Oreochromis niloticus. Ingredients were incorporated to a practical reference diet at a 7 : 3 ratio (70% of reference diet and 30% of test ingredient). Chromic oxide was used as external digestibility marker. Among animal products poultry by‐product meal (PBM; 89.7%) and FM (88.6%) presented the highest apparent protein digestibility (APD) while MBM (78.4%) and feather meal (78.5%) presented the lowest APD. Among plant protein‐rich products CGM (91.4%) and SBM (92.4%) presented the highest APD values while cottonseed meal‐28 presented the lowest APD (78.6%). Average apparent amino acid availability of feed ingredients was similar to protein digestibility with 92.3%, 89.6%, 73.4%, 80.7%, 88.9%, 84.4%, 91.2% and 79.7% values for SBM, CGM, cottonseed meal‐28 and 38, FM, MBM, PBM and feather meal respectively. These results indicate that O. niloticus is able to utilize efficiently different feedstuffs.     

In Memoriam Karl Boshart

Ohne Zusammenfassung     

Responsiveness to Progestagen-eCG-Cloprostenol Treatment in Goat Food Restricted for Long Period and Refed

For 6 months, 10 adult Saanen crossbred goats were fed undernutrition diet (70% maintenance), and finally five goats were refed for 6 weeks with 150% maintenance. In all animals oestrus was synchronized using 45 mg FGA vaginal sponge for 11 days, 300 IU eCG and 50 microg cloprostenol 48 h prior to sponge removal. From oestrus onset, during a 24-h period, blood samples were collected for oestradiol and NEFA assay. Ovulation was verified by laparoscopy 3 days after sponge removal. Body mass loss was 18.62 +/- 3.03% of initial weight and in refed goats body weight recovery was 90.63 +/- 3.56%. NEFA level was higher in restricted goats (p < 0.05). Fifty per cent of underfed goats (2/4) and all refed goats (4/4) exhibited oestrus and ovulation. Significant relationship (p < 0.05) was found between weight loss and the interval sponge removal-oestrus onset (r = 0.91) or ovulation rate (r = 0.70). Only in the refed group was the ovulation rate related to the oestradiol amount (r = 0.99) (p < 0.05). Collectively results showed that a short period of improved feeding re-established the responsiveness of oestrus synchronization in chronically fasted goats.