Veterinary Clinics of North America: Food Animal Practice This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Implementing Fixed-Time Artificial Insemination Programs in Beef Herds
The article discusses the importance of reproductive biotechnologies, including artificial insemination and fixed-time artificial insemination (TAI), in beef cow-calf operations. The use of TAI improves cow-calf productivity and profitability by shortening the breeding season and increasing the number of calves born earlier, resulting in heavier calves at weaning. However, adoption of TAI by beef producers in the United States has been slow compared with the dairy industry and internationally, such as Brazil. Current TAI protocols are effective in synchronizing ovulation and yield consistent pregnancy results. Factors affe...
Source: Veterinary Clinics of North America: Food Animal Practice - September 6, 2023 Category: Veterinary Research Authors: Vitor R.G. Mercadante, Graham Cliff Lamb Source Type: research

Considerations for Using Natural Service with Estrous Synchronization Programs
Estrous synchronization, coupled with natural service, provides the benefit of female cows conceiving early, but there are an increased number of females expressing estrus in a short period of time. Thus, considerations need to be made for the bull. Select a protocol that will distribute estrus over a longer period of time and ensure bulls pass a breeding soundness examination. Mature bulls (3  years old or older) have increased efficiency in getting cows pregnant compared with younger bulls; therefore, a ratio of 1 mature bull to 25 cows is a good recommendation within an estrous synchronized herd. (Source: Veterinary Cl...
Source: Veterinary Clinics of North America: Food Animal Practice - September 6, 2023 Category: Veterinary Research Authors: George A. Perry Source Type: research

Trace Mineral Supplementation for Beef Cows
Range mineral supplementation is based on providing trace minerals not adequately provided from grazed forage in meeting beef cattle needs throughout life cycle stages. Supplementation programs should be developed with consideration of ranch production goals, economics, and practicality for implementation. Factors such as season of grazing, forage analysis, water analysis including antagonistic elements, and measured animal responses are used in mineral supplement formulation for range cattle. Mineral intake is a critical factor to a supplement program ’s success. Salt-based mineral products are most used under range con...
Source: Veterinary Clinics of North America: Food Animal Practice - September 6, 2023 Category: Veterinary Research Authors: Bob Sager, Robert J. Van Saun Source Type: research

Genomics and Dairy Bull Fertility
Current evidence suggests that dairy bull fertility is influenced by genetic factors, and hence, it could be managed and improved by genetic means. There are major mutations that explain about 4% to 8% of the observed differences in conception rate between bulls segregating in most dairy breeds. Research has shown that genomic prediction of bull fertility is possible, and this could be used to make accurate genome-guided selection decisions, such as early culling of predicted subfertile bull calves. Inbreeding negatively influences bull fertility, and the increase in homozygosity seems an important risk factor for dairy bu...
Source: Veterinary Clinics of North America: Food Animal Practice - September 4, 2023 Category: Veterinary Research Authors: Francisco Pe ñagaricano Source Type: research

Frozen Bovine Semen Storage, Semen Handling, and Site of Deposition
Artificial insemination (AI) is an effective strategy to distribute semen from elite sires and improve the genetics of a herd. Commercial studs provide a fertile semen product to their customers. Consequently, the maintenance of sire fertility is dependent upon appropriate semen storage, handing, and site of semen deposition. When retrieving a straw of frozen semen, the cane (and canister containing canes) should be held below the frost-line and limited to 8 seconds in the neck of the tank. After appropriate thawing, and continuous thermoregulation of the AI gun containing the thawed semen, semen should be deposited in the...
Source: Veterinary Clinics of North America: Food Animal Practice - September 4, 2023 Category: Veterinary Research Authors: Joseph C. Dalton Source Type: research

Trace Mineral Nutrition of Sheep
Trace mineral nutrition of sheep often focuses on their greater susceptibility to copper toxicosis due to a lesser biliary excretion ability compared with other ruminants. Our understanding of sheep trace mineral requirements has improved for most elements allowing for a factorial approach to determining daily requirement instead of a dietary concentration. Forage trace mineral content is influenced by many factors making issues of trace mineral supplementation geographic-dependent. Oral delivery of trace elements is a preferred supplementation method, and this can be achieved through free choice trace mineralized salt or ...
Source: Veterinary Clinics of North America: Food Animal Practice - August 26, 2023 Category: Veterinary Research Authors: Robert J. Van Saun Source Type: research

Trace Minerals in Ruminant Production Systems
At one time or other, deficiencies of almost all of the essential nutrients have been considered to cause infertility in the cow.1 (Source: Veterinary Clinics of North America: Food Animal Practice)
Source: Veterinary Clinics of North America: Food Animal Practice - August 26, 2023 Category: Veterinary Research Authors: William S. Swecker, Robert J. Van Saun Tags: Preface Source Type: research

Trace Mineral Nutrition in Confinement Dairy Cattle
Veterinarians are often called upon to diagnose health-related issues on the farm that may be related to trace mineral deficiencies or toxicities. Trace mineral feeding rates are often not available due to the proprietary nature of the trace mineral premixes provided by nutritional consultants. The veterinarian needs to be aware of the common clinical signs of trace mineral deficiencies and toxicities, interactions between trace minerals that may result in deficiencies, clinical samples that are necessary for the proper diagnosis, and the recommended normal ranges of each trace mineral depending on the age of the animal. (...
Source: Veterinary Clinics of North America: Food Animal Practice - August 14, 2023 Category: Veterinary Research Authors: Robert B. Corbett Source Type: research

Common Toxicosis
Veterinarians are often called upon to diagnose health-related issues on the farm that may be related to trace mineral deficiencies or toxicities. Trace mineral feeding rates are often not available due to the proprietary nature of the trace mineral premixes provided by nutritional consultants. The veterinarian needs to be aware of the common clinical signs of trace mineral deficiencies and toxicities, interactions between trace minerals that may result in deficiencies, clinical samples that are necessary for the proper diagnosis, and the recommended normal ranges of each trace mineral depending on the age of the animal. (...
Source: Veterinary Clinics of North America: Food Animal Practice - July 19, 2023 Category: Veterinary Research Authors: John P. Buchweitz, Rachel Sheffler, Birgit Puschner Source Type: research

Vitamins and Trace Minerals in Ruminants
Trace minerals and vitamins are essential for optimizing feedlot cattle growth, health, and carcass characteristics. Understanding factors that influence trace mineral and vitamin absorption and metabolism is important when formulating feedlot cattle diets. Current feedlot industry supplementation practices typically exceed published trace mineral requirements by a factor of 2 to 4. Therefore, the intent of this review is to briefly discuss the functions of trace minerals and vitamins that are typically supplemented in feedlot diets and to examine the impact of dose of trace mineral or vitamin on growth performance, health...
Source: Veterinary Clinics of North America: Food Animal Practice - July 14, 2023 Category: Veterinary Research Authors: Claire Okoren, John J. Wagner, Lily N. Edwards-Callaway, Terry E. Engle Source Type: research

Field Morphology and Interpretation
Semen morphology evaluation in the field should always be performed at 1000 × with oil immersion. The development of a spermiogram will aid the practitioner to interpret potential fertility of semen at the time of sampling as well as determine potential causes of an abnormal spermiogram. Bulls, which experience stress or impairment of thermoregulation of the testes for any reason, often experience a transitory decrease in the quality of sperm morphology. This can be recognized by a sequence of appearances of morphologic defects coupled with a thorough patient history. (Source: Veterinary Clinics of North America: Food Animal Practice)
Source: Veterinary Clinics of North America: Food Animal Practice - July 12, 2023 Category: Veterinary Research Authors: Jennifer H. Koziol Source Type: research

Ancillary Methods for Semen Evaluation
The cause of subfertility or poor fertility in naturally mated bulls should be differentiated from impotentia coeundi, generandi, or erigendi prior to ancillary semen evaluation. Bulls used for artificial insemination may undergo ancillary semen evaluation following low fertility rates as judged by poor conception or low pregnancy rates. Morphologically abnormal sperm have long been associated with bull subfertility and infertility. Some morphological defects such as improper sperm chromatin condensation are not visible using traditional light microscopy and require specialized staining. Ancillary semen evaluation is usefu...
Source: Veterinary Clinics of North America: Food Animal Practice - July 11, 2023 Category: Veterinary Research Authors: Jennifer H. Koziol Source Type: research

Trace Mineral Metabolism
Trace minerals are essential nutrients that have many biologic functions, many of which are related to metabolic activities, immune function, and antioxidant capacity. The pregnant dam provides essential nutrients to support fetal development, including trace minerals. Milk is known to be an insufficient source of many trace minerals during the early nursing neonatal period. The fetal liver is capable of concentrating minerals to generate a reserve for use during postnatal life; however, the sufficiency of this reserve is dependent upon maternal mineral status. Appropriate mineral supplementation in the gestational diet is...
Source: Veterinary Clinics of North America: Food Animal Practice - July 11, 2023 Category: Veterinary Research Authors: Robert J. Van Saun Source Type: research

Trace Mineral Supplementation of Beef Cattle in Pasture Environments
The United States Department of Agriculture defines pastureland as “A land cover/use category of land managed primarily for the production of introduced forage plants for livestock grazing.” The purpose of this article is to review trace mineral supplementation for beef cattle in this environment. Supplementation of trace minerals in these environments is accom plished with the use of a trace mineralized salt or a complete mineral-vitamin product that contains macrominerals, trace minerals, and vitamins. The form of the supplement may influence uptake and utilization. Supplementation may be augmented with pulse dosing ...
Source: Veterinary Clinics of North America: Food Animal Practice - July 6, 2023 Category: Veterinary Research Authors: William S. Swecker Source Type: research

Vitamin and Trace Element Nutrition of Stocker Cattle on Small Grain and Winter Annual Pastures
This article reviews the trace mineral and macro mineral content of small grain forages and the potential role in the health of cattle grazing the forages. Reasons for the variability of trace mineral content in small grain forages are discussed, as well as the role of antagonists, such as sulfur and molybdenum, in creating trace mineral deficiencies. The sampling of cattle for the determination of trace mineral statues is described, including which samples to collect for analysis, as well as sample handling. The authors offer a useful discussion on the vitamin content of small grain forages, and conclude that vitamin supp...
Source: Veterinary Clinics of North America: Food Animal Practice - July 6, 2023 Category: Veterinary Research Authors: Paul A. Beck, Jeffery O. Hall Source Type: research