Factors important for bull purchasing decisions and management in extensive rangeland production systems of New Mexico: a producer survey.

There were 463,000 head of beef cows in New Mexico as of January 1, 2021 (NASS, 2020), down roughly 4% from 2020 (NASS, 2019). Frequent drought often results in herd reduction and loss of valuable genetic progress. Bull selection is critical due to their influence on herd development. A survey was conducted to identify traits important to bull selection in New Mexico. Surveys were collected digitally (n = 83) and via the mail (n = 74). Responses were largely by cow/calf producers averaging 57 ± 1 years old with 24 ± 1 years' experience. Survey respondents represented 4,384,296 acres of private owned, private leased, and leased public rangeland and irrigated pasture meadow in New Mexico and surrounding states. Average cow/calf operation size was 294 ± 39 head and average bull herd size was 21 ± 3 head. Average price paid for a bull in the past 2 years was $3,981 ± 213. Physical characteristics, individual bull performance information, and genetic information are all important traits to New Mexico bull buyers; however, most producers (56%) indicated that structural soundness was the most important factor influencing their selection decisions. Amongst expected progeny differences (EPDs), New Mexico producers consider the calving ease direct (CED) and birth weight (BW) EPDS to be most important (40% and 35%, respectively). Producers also indicated that multitrait selection indexes used by the American Angus Association were important to their selection decisions, with the beef value ($B) and weaned calf value ($W) indexes being cited most often (35% and 31%, respectively). Elements important to bull purchase include the bull's sale preview (87%), body condition score (86%), feed efficiency/average daily gain information (85%), and actual scrotal circumference (82%). Following purchase of a new bull, most (60%) keep the bull separate from the cow herd until the following breeding season, while the remaining 40% of producers turn newly purchased bulls out within 30 days of purchase. Sixty eight percent of producers evaluate semen quality annually or prior to the start of the breeding season. Interestingly, 39% of producers indicated they used reproductive technologies like artificial insemination and synchronization of estrus while most (80%) test for trichomoniasis. The primary factor influencing culling decisions is age, followed by soundness and fertility.

Projected temperature increases may require shifts in the growing season of cool-season crops and the growing locations of warm-season crops.

Predicting the effects of climate change on where and when crops can be grown under future conditions is critical for maintaining crop production, particularly in Mediterranean ecosystems. The diverse range of Mediterranean climatic conditions in California supports high crop diversity and production, yet California also faces future increased temperatures and more frequent extreme weather events indicative of a changing climate. Evaluating the effect of temperature increase is a crucial first step in estimating future impacts of warming. We compare the temperature constraints under climate projections for five annual crops. We determine maximum and minimum monthly temperatures of historical and future projections for the mid-21st century based on four climate projections (two climate models × two climate change scenarios). We estimate where temperatures were suitable for each crop historically and in the future at two spatial scales (4 km grid-cell; statewide) and two temporal scales (monthly; for each crop's growing season). We found differences between warm- and cool-season crops: temperature affects when cool-season crops (broccoli; lettuce) could be grown more than where, but temperature affects where warm-season crops (cantaloupe; tomato; carrots) could be grown more than when. More than 99% of land where lettuce and broccoli have been grown historically will have temperatures suitable for each crop by mid-century; the increased winter temperatures will enable spring and fall growing seasons to merge in more than 75% of land where each crop has been grown. Only 34-87% of land historically used for growing tomatoes will have temperatures appropriate for tomatoes due to the increase in summer temperatures. We do not predict cantaloupes and carrots to cross their upper temperature threshold. Integration of our results with other factors that affect crops - including management, water availability and helpful and harmful insects - provides guidance for adapting Mediterranean agriculture to climate change.