The purpose of this study was to evaluate the relative efficacy and cost-effectiveness of feeding melengestrol acetate (MGA) to feedlot heifer calves in western Canada. Heifers fed MGA had significantly (P less than .05) improved average daily gain, feed conversion, and carcass quality grade and lower rates of initial undifferentiated fever treatment and bovine respiratory disease mortality. However, heifers fed MGA had less desirable (P less than .05) carcass yield grade. There was a net economic advantage of Can $11.31/animal in favor of heifers fed MGA. Based on these results, it is efficacious and cost-effective to feed MGA to heifer calves raised in standard large-pen commercial feedlots in western Canada.
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J Dairy Sci
January 2025
ICREA (Institució de Recerca i Estudis Avançats), 08010 Barcelona, Spain; Department of Animal and Veterinary Sciences, Universitat de Lleida, 25198 Lleida, Spain.
Sustainable alternatives to high environmental input feed ingredients are important to reducing the environmental impact of animal agriculture. Protein and oil extracted from cultivation of black soldier fly (Hermetia illucens) larvae (BSFL) on waste feedstocks such as manure, food waste and plant residues could be a suitable source of nutrients. The oil from BFSL contains large amounts of saturated fatty acids, particularly lauric acid, and may be a more sustainable alternative to palm and coconut oils that are currently used in calf milk replacers in many parts of the world.
View Article and Find Full Text PDFAm J Vet Res
January 2025
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA.
Objective: To describe immune responses following administration of experimental Salmonella Dublin siderophore receptor protein (SRP) vaccines in Holstein heifer calves with adequate passive antibody transfer.
Methods: Calves were randomly assigned to receive placebo, vaccination with S Dublin SRP in adjuvant A, or vaccination with S Dublin SRP in adjuvant B at 7 ± 3 days of age and 3 weeks later. Before each vaccination, 4 and 8 days after the second vaccination (postvaccination), and 61 to 91 days postvaccination, S Dublin antibody titers were measured.
Vet Sci
December 2024
Department of Animal Sciences and Center for Nutrition and Pregnancy, North Dakota State University, Fargo, ND 58108, USA.
Two experiments assessed the effects of providing a vitamin and mineral supplement to gestating beef heifers on concentrations of immunoglobulins (Ig) in colostrum and calf serum 24 h after feeding maternal colostrum (Exp. 1) or a colostrum-replacement product (Exp. 2).
View Article and Find Full Text PDFPlacenta
January 2025
Department of Animal Sciences, University of Florida, Gainesville, USA. Electronic address:
Introduction: Maternal hyperthermia (i.e. heat stress) can adversely affect placental development and function, with severity varying based on pregnancy stage.
View Article and Find Full Text PDFOne-carbon metabolism (OCM) is a series of connected pathways involving the methionine-folate cycles, transsulfuration, polyamine synthesis, nucleotide synthesis, free-radical scavenging, and energy metabolism. These pathways functionally depend upon amino acids (methionine, glycine, and serine), vitamins (folate, B, B, and B), and minerals (sulfur, cobalt, and zinc). Growing bodies of research indicate that in beef cattle, physiological stage, nutritional plane, diet, species (Bos taurus vs.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!