Effects of infection with parainfluenza-3 virus and infectious bovine rhinotracheitis virus on neutrophil functions in calves

Calves were challenge exposed in separate experiments with parainfluenza-3 (PI-3) virus or infectious bovine rhinotracheitis (IBR) virus. Blood neutrophils were assayed for functional activity every other day for at least 3 weeks by random migration, Staphylococcus aureus ingestion, antibody-dependent cell-mediated cytotoxicity, cytochrome-c reduction, iodination, and native chemiluminescence. Exposure to PI-3 virus resulted in a brief febrile response and no other clinical signs. Alterations in total or differential WBC counts were not detected. Chemiluminescence and iodination activities were reduced from activities before exposure. Exposure to IBR virus resulted in mild clinical signs and a febrile response of several days' duration. Total WBC and mononuclear cell counts were reduced. Random migration was reduced, whereas S aureus ingestion was enhanced. We concluded that infection of calves with IBR virus and PI-3 virus might directly or indirectly result in alterations of neutrophil function. The functional alterations apparently are different for each virus. These virus-induced alterations in neutrophil function might predispose calves to secondary bacterial pneumonia.     

The metabolism of carboxin in growing barley

The major soluble metabolite of carboxin (2,3-dihydro-6-methyl-5-phenylcarbamoyi-1,4-oxathiin) in barley seedlings and mature plants was identified as the-hydroxy phenyl derivative. This phenol was also bound to the lignin fraction. The distribution of carboxin and its metabolites in seedlings and mature plants grown from treated seed was studied; maximum residues were found in the three oldest internodes, with traces in the roots and flowering heads. Treated plants had altered chlorophyll/carotenoid ratios, and raised levels of some free amino acids.     

Influence of sex chromosomes on laying-house performance of chickens

A special population segregating for the sex chromosome was developed to estimate the Z and W sex chromosome effects sampled from a Fayoumi (Egyptian) breed and a heavy‐breed synthetic population. Analysis of 2 years’ data from more than 3000 pullets indicate that both sex chromosomes influence age at first egg with the Z being the more important. Pullets with the heavy‐breed Z chromosome matured 17 d earlier and laid 5% more eggs than those with the Fayoumi Z. The heavy‐breed W chromosome showed a 7‐d advance in maturity but otherwise with no significant effect on egg production.

Although this experiment was designed to estimate parameter differences between two breeds, the design can be generalised to estimate the distribution of genetic differences due to autosomes, sex chromosomes, heterosis and maternal influences both between and within avian populations.     

High-Temperature Treatment (Blindstoken) of Bulbs of Tulip cv Rose Copland for Flower Killing and Yield Improvement

A three-year experiment on the high-temperature treatment of tulip bulbs established that yield could be increased by between 8 and 31 % for bulb weight or between 14 and 29 % for numbers of large bulbs, depending upon season, associated with a near-complete flower kill. The optimum pre-treatment storage temperature was 17°C, and the best date (of the five tested) for starting blindstoken at 33°C for one week was 20th-21st September.

Yield increases were greater when the blindstoken treatment was applied to bulbs whose shoots were short; later treatment, or treatment after pre-treatments which allowed faster shoot growth, were less effective. For optimum flower kill and yield increase the shoot should be about 1 cm high at treatment. Bulb weight and large bulb number were correlated, suggesting that the treatment increases total bulb weight by increasing bulb size rather than by differentially affecting the growth of daughter bulbs.

No adverse effects of the treatments were observed when the bulbs were forced in a glasshouse the following season.     

Transmission of bovine coronavirus and serologic responses in feedlot calves under field conditions

OBJECTIVE: To compare shedding patterns and serologic responses to bovine coronavirus (BCV) in feedlot calves shipped from a single ranch in New Mexico (NM calves) versus calves assembled from local sale barns in Arkansas (AR calves) and to evaluate the role of BCV on disease and performance. ANIMALS: 103 feedlot calves from New Mexico and 100 from Arkansas. PROCEDURES: Calves were studied from before shipping to 35 days after arrival at the feedlot. Nasal swab specimens, fecal samples, and serum samples were obtained before shipping, at arrival, and periodically thereafter. Bovine coronavirus antigen and antibodies were detected by use of an ELISA. RESULTS: NM calves had a high geometric mean titer for BCV antibody at arrival (GMT, 1,928); only 2% shed BCV in nasal secretions and 1% in feces. In contrast, AR calves had low antibody titers against BCV at arrival (GMT, 102) and 64% shed BCV in nasal secretions and 65% in feces. Detection of BCV in nasal secretions preceded detection in feces before shipping AR calves, but at arrival, 73% of AR calves were shedding BCV in nasal secretions and feces. Bovine coronavirus infection was significantly associated with respiratory tract disease and decreased growth performance in AR calves. CONCLUSIONS AND CLINICAL RELEVANCE: Replication and shedding of BCV may start in the upper respiratory tract and spread to the gastrointestinal tract. Vaccination of calves against BCV before shipping to feedlots may provide protection against BCV infection and its effects with other pathogens in the induction of respiratory tract disease.     

Early generation selection for yield and breadmaking quality of hard red spring wheat (Triticum aestivum L. em thell.)

Summary Evaluation of the effect of selection in 3 different F₃ populations of hard red spring wheat was achieved for yield and breadmaking quality parameters by examining the subsequent performance of F₃ selections as populations of F₅ lines. For baking absorption the mean performance of the F₅ populations was positively related to the performance of the F₃ selections in each of the 3 population-years. A significant relationship between the performance in F₃ and in F₅ was not obtained in any of the 3 years for bushel weight, flour ash, remix loaf volume, farinograph mixing tolerance index or for flour color grade. A high positive relationship between performance in F₃ and F₅ was found in two out of three years for protein content, flour protein content and 1,000-kernel weight. Predictive ability for sedimentation value, flour yield, farinograph development time and blend loaf volume was inconsistent for different population-years.A positive relationship between the yield of F₃ plots and the mean yield of F₅ populations was found in only 1 year. In the other 2 years the relationship between F₃ and F₅ yields ranged from nonsignificant to low, negative and significant. The latter results were possibly related to the relatively narrow high yielding range of the total F₃ variability for yield which was sampled in each of those years. In all 3 population-years the highest yielding F₅ populations were derived from F₃ lines which were high yielding on a plot basis and also very high yielding relative to the yield of their adjacent control in the F₃ nursery.Broad sense heritabilities calculated for the F₅ generation support the thesis that selection between F₃-derived populations would be a worthwhile plant breeding procedure for many of the breadmaking quality parameters.Contribution number 267 of the Department of Plant Science, University of Manitoba.     

Successful Non-Surgical Transfer of Horse Embryos to Mule Recipients

Mules, hybrids resulting from the mating of a horse mare (Equus caballus, 2n = 64) to a Jack donkey (E. asinus, 2n = 62), are generally infertile. Five horse embryos were transferred non‐surgically to two cyclic and one acyclic recipient mules. In the mares and cycling mules, oestrus and ovulation were induced with, respectively, d ‐cloprostenol and human chorionic gonadotrophin (hCG). The acyclic mule, on the other hand, received oestradiol benzoate when the embryo donor was showing oestrus and progesterone after the donor had ovulated and until pregnancy diagnosis. Non‐surgical embryo collections were attempted on day 7 after ovulation and recovered embryos were transferred transcervically into the mules’ uteri. Mules that became pregnant were blood sampled serially for equine chorion gonadotrophin (eCG), progestagen and total conjugated oestrogen concentrations until around 6 months of gestation. The three embryos transferred to the acyclic mule did not produce any pregnancies whereas both embryos transferred to the cycling mules resulted in the birth of live foals. The peak concentration and duration of secretion of eCG differed markedly between the two pregnant mules, although both animals appeared to develop secondary corpora lutea beyond day 40 of gestation, as in normal intraspecies horse pregnancy. Moreover, the rise in serum oestrogen concentrations from around day 90 was also similar to that seen in normal pregnant mares. Parturition occurred spontaneously on day 348 of gestation in both mules and the resulting colt foals developed normally to weaning. Thus, cycling mules can carry a horse conceptus after non‐surgical embryo transfer and give birth to a normal mature foal.