A crossover study design was used in five commercial dairy herds to study the effect of altering the switch point settings for automatic cluster remover units on the average duration of unit attachment, milk flow, and milk yield. Automatic cluster remover switch point settings were alternated, for 1-wk periods, between 0.50 and 0.64 kg/min (1.1 and 1.4 lb/min) in one herd and between 0.73 and 0.82 kg/min (1.6 and 1.8 lb/min) in the four remaining herds. Parlor data were captured at 329 separate milking sessions (range 39 to 92 per herd), representing 239,393 individual cow milkings. While increasing the automatic cluster remover switch point setting was not associated with a change in average milking duration in one herd, it had the effect of significantly reducing the average milking duration by between 10.2 and 15.6 s per cow in the remaining four herds. Milk flow was significantly increased at higher switch point settings for all five herds. Higher automatic cluster remover switch point settings did not have a negative effect on milk yield in any of the herds studied and, in fact, were associated with increased milk yield in two of the five herds. Decreasing milking duration while either maintaining or increasing the volume of milk harvested should ultimately lead to improved milking efficiency and parlor performance. Modifying systems to increase automatic cluster remover switch point settings offers an important potential opportunity to increase parlor efficiency in commercial dairy herds.

BackgroundTumour hypoxia limits the effectiveness of radiation therapy. Delivering normobaric or hyperbaric oxygen therapy elevates pO2 in both tumour and normal brain tissue. However, pO2 levels return to baseline within 15 minutes of stopping therapy.AimTo investigate the effect of perfluorocarbon (PFC) emulsions on hypoxia in subcutaneous and intracranial mouse gliomas and their radiosensitising effect in orthotopic gliomas in mice breathing carbogen (95%O2 and 5%CO2).ResultsPFC emulsions completely abrogated hypoxia in both subcutaneous and intracranial GL261 models and conferred a significant survival advantage orthotopically (Mantel Cox: p = 0.048) in carbogen breathing mice injected intravenously (IV) with PFC emulsions before radiation versus mice receiving radiation alone. Carbogen alone decreased hypoxia levels substantially and conferred a smaller but not statistically significant survival advantage over and above radiation alone.ConclusionIV injections of PFC emulsions followed by 1h carbogen breathing, radiosensitises GL261 intracranial tumors.

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The human population is ever increasing while the quality and quantity of natural resources used for livestock production decline. This calls for improved product efficiency and the development of improved and sustainable cattle production methods to produce higher quality products to satisfy the demands of both the modern and transient world. The goal of this review was to summarize the interactions, challenges, and opportunities in cattle production relating to their endocrine system, and how reproductive hormones and others impact economically important traits, animal welfare, and human health. A comprehensive literature search was conducted with a focus on analysis of natural hormones and the use of exogenous hormone administration for reproduction, growth, and development of beef and dairy cattle. Hormones regulate homeostasis and enhance important traits in cattle, including fertility, growth and development, health, and the production of both meat and milk products. Reproductive hormones such as testosterone, estradiol, progesterone, and related synthetics like trenbolone acetate and zeranol can be strategically utilized in both beef and dairy cattle production systems to enhance their most valuable traits, but the impact of these substances must account for the welfare of the animal as well as the health of the consumer. This scientific review provides a comprehensive analysis of the bovine endocrine system’s impact on food animals and product quality which is vital for students, researchers, livestock producers, and consumers. Although important advances have been made in animal science and related technological fields, major gaps still exist in the knowledge base regarding the influence of hormones on the production and welfare of food animals as well as in the public perception of hormone use in food-producing animals. Filling these gaps through transformative and translational research will enhance both fundamental and applied animal science to feed a growing population.

Proper fetal nutrition via adequate uteroplacental blood flow is critical for maximizing fetal development and reducing mortality. However, our understanding of adaptations during maternal nutrient restriction is incomplete. The purpose of this study was to determine the effect of nutrient restriction during mid to late gestation on utero-placental hemodynamics and placentome morphometrics in gestating beef cattle. Animals (n = 10) were randomly assigned one of 2 treatments: Control (CON; 100% NRC Requirements) vs Restricted Feed (NR; 60% of NRC Requirements) from 140 to 240 days of gestation. Hemodynamic parameters were collected by Doppler ultrasonography 1 week prior to slaughter from the ipsilateral and contralateral uterine arteries, after which, total uterine artery blood flow was calculated. Six animals (n = 3 per treatment) were slaughtered on day 240 of gestation (Group 1) and the remaining 4 animals were slaughtered on 265 ± 15 days (Group 2). Placentome tissues were harvested for weight and number determination. Placentome number decreased (P = 0.01) in nutrient restricted (49 ± 6) versus control (83 ± 6) fed dams. There was an interaction between treatment and group in which ipsilateral diameter increased (P < 0.05) in group 2 NR animals versus group 2 CON animals while there was no difference between NR and CON in group 1. There was no difference (P = 0.30) in total uterine artery blood flow in fetal weight, which averaged 212 ± 37 mL/min*kg in nutrient restricted versus 153 ± 34 mL/min*kg in control fed dams. In summary, these data indicate limited alterations in uterine artery blood flow and fetal weight in nutrient restricted dams during the last half of gestation. The decrease in placentome number with no difference in placentome weight could indicate larger placentomes in nutrient restricted dams were able to compensate for the reduction in total number.