California Agriculture

Monensin is known to improve feed efficiency in cattle. At higher doses, however, monensin reduces the palatability of mineral supplements, which may reduce consumption of essential minerals such as selenium. The main objective of this study was to compare weight gain, while evaluating the impact on blood selenium concentrations, among treatment and control groups of stocker calves supplemented with a self-fed mineral supplement designed to deliver different amounts of monensin, while the control group received the same mineral without monensin. A secondary objective was to compare the presence of pathogenic and total coccidia oocysts. At study end, all monensin treatment groups weighed more than the control group but were not different from each other. No effect was detected on coccidia oocysts. In sum, there is a production gain from providing monensin in a mineral supplement to weaned calves on pasture. However, too high a dose may lead to insufficient trace mineral consumption. This is a concern in areas where forage is deficient in these nutrients.

Colostrum feeding provides immunoglobulins, in a process called transfer of passive immunity, which is critical for dairy calf health and welfare. However, failure of transfer of passive immunity (FTPI) occurs in about 12% of calves nationwide. This study compares the prevalence of FTPI between calves raised on organic and conventional dairy farms, describes the colostral management practices on organic dairy farms in California, and recommends improvements. We compared serum immunoglobulin G (IgG) concentrations between calves raised on organic and conventional dairies and found that the odds of FTPI in calves raised in organic dairies were 2.5 times greater than in calves raised in conventional dairies. Focusing on varied practices in organic dairies, FTPI was 2.9 times more likely in calves fed less than 4 liters of colostrum within the first 24 hours, compared to calves fed more than that amount. We also found that organic dairy producers did not routinely monitor colostral IgG concentrations and passive immunity status. We recommend that organic dairy farmers adopt these practices to decrease the prevalence of FTPI in calves.

Field edge hedgerows have long been promoted by UC Cooperative Extension and other organizations as a way to bring needed biodiversity to California farms. However, adoption of hedgerow planting still falls far short of available edge capacity. Our study explores a new multifunctional model of hedgerows that combines production with environmental conservation goals by considering the revenue potential of harvesting blue elderberry. Blue elderberry is a drought-tolerant native species well adapted to multiple microclimates in California and the western United States. The growth of elderberry herbal products and specialty foods markets is currently skyrocketing nationally and globally, and blue elderberry may offer a promising entry into these markets. Blue elderberry is also sought out by Indigenous people as one important component in efforts to restore cultural and food sovereignty. A field demonstration trial in the southern Sacramento Valley found that elderberry yields from 1,000-foot-long multi-species hedgerows could potentially provide from $2,000 to $3,000 in net annual revenue within 3 to 5 years, with much more possible as the hedgerows mature.