Pregnancy diagnosis in sows: a comparison of the vaginal biopsy and Doppler ultrasound techniques.

Two pregnancy diagnosis techniques, vaginal biopsy and ultrasonic detection, were applied to 190 sows following service. Of 172 sows diagnosed pregnant by vaginal biopsy, five did not farrow. Of 18 sows judged not pregnant, one produced a litter. With the ultrasound technique, 175 sows were diagnosed pregnant, but 11 did not farrow. Of the remaining 15 sows considered not pregnant by the 39th day after service, four farrowed. The biopsy result was usually available up to 48 hours earlier than the ultrasound result. It was concluded that where laboratory facilities are available, the biopsy technique is the method of choice.     

Alleviation of salt stress by arbuscular mycorrhizal in zucchini plants grown at low and high phosphorus concentration

With the aim of determining whether the arbuscular mycorrhizal (AM) inoculation would give an advantage to overcome salinity problems and if the phosphorus (P) concentration can profoundly influence zucchini (Cucurbita pepo L.) plant responses to AM, a greenhouse experiment was carried out with AM (+AM) and non-AM (−AM). Plants were grown in sand culture with two levels of salinity (1 and 35 mM NaCl, giving electrical conductivity values of 1.8 and 5.0 dS m⁻¹) and P (0.3 and 1 mM P) concentrations. The percentages of marketable yield and shoot biomass reduction caused by salinity were significantly lower in the plants grown at 0.3 mM P, compared to those grown at 1 mM P. However, even at high P concentration, the absolute value of yield and shoot biomass of +AM zucchini plants grown under saline conditions was higher than those grown at low P concentration. The +AM plants under saline conditions had higher leaf chlorophyll content and relative water content than −AM. Mycorrhizal zucchini plants grown under saline conditions had a higher concentration of K and lower Na concentration in leaf tissue compared to −AM plants. The P content of zucchini leaf tissue was similar for +AM and −AM treatments at both low and high P concentrations in the saline nutrient solution. The beneficial effects of AM on zucchini plants could be due to an improvement in water and nutritional status (high K and low Na accumulation).