Antibiotic versus nonantibiotic products for the treatment of Papillomatous Digital Dermatitis (hairy heel wart) in dairy cattle

A field trial was conducted to compare oxytetracycline to three nonantibiotic therapies using bandage protocols for the treatment of hairy heel warts. Affected feet were bandaged for 4 days with either of the four products. Over a 28-day period following bandage removal, heel warts on 44 cows (11 per treatment group) were evaluated based on size, degree of pain, color, and lesion appearance. No differences were detected among treatments, suggesting that nonantibiotic therapies used in bandage protocols may be as effective as oxytetracycline.; Dairy Day, 2000, Kansas State University, Manhattan, KS, 2000

Effects of energy level on methionine utilization by growing steers

The objective of this study was to evaluate the effect of energy level on amino acid utilization in growing steers. Six ruminally cannulated Holstein steers (503 lb) were limit-fed (6.2 lb/day dry matter) a diet based on soybean hulls (83%), wheat straw (7.6%), and cane molasses (4.1%). The treatments consisted of the infusion of two methionine levels (0 or 3 g/d) and three energy levels (0, 1.3, or 2.6 Mcal ME/day) in a 2 x 3 factorial arrangement. Energy was supplied through ruminal infusion of acetate, propionate, and butyrate and through abomasal infusion of glucose and fat in increasing amounts. No interactions between methionine and energy level were observed. Nitrogen balance was increased by methionine supplementation, indicating that this amino acid limited protein deposition. A linear increase in nitrogen retention was found with the increase in energy. These improvements in protein deposition were related to reductions in urinary nitrogen excretion, reduced plasma-urea concentrations, and greater circulating concentrations of insulin and insulin-like growth factor-I. The results of this study suggest that amino acid utilization can be improved by increasing energy. These effects could be partly explained by variations in plasma concentration of key hormones involved in the control of protein deposition

Relative value of ruminally degradable and undegradable protein on the utilization of low-quality prairie hay by steers

An experiment was performed to investigate the impact of providing six levels of ruminally degradable protein (RDP; protein that is available to ruminal microbes) in combination with two levels of ruminally undegradable protein (RUP; protein that is not available to the ruminal microbes, but can be digested directly by cattle) on the intake and digestion of low-quality prairie hay. Twelve steers were provided unlimited access to low-quality prairie hay (5.3% crude protein and 71.7% neutral detergent fiber) throughout the trial. To simulate dietary RUP, casein was infused abomasally once daily at either 0 or 0.087% of body weight. To simulate dietary RDP, casein was infused ruminally once daily at 0, 0.029, 0.058, 0.087, 0.116, or 0.145% of body weight. As provision of RDP increased, forage intake and fiber digestion increased. Supplementing with RUP alone increased forage intake but not fiber digestion, although the intake response was not as large as providing the same amount of RDP. In conclusion, RUP is less efficient than RDP in stimulating forage intake and digestion

Lipolysis drives expression of the constitutively active receptor GPR3 to induce adipose thermogenesis

Thermogenic adipocytes possess a therapeutically appealing, energy-expending capacity, which is canonically cold-induced by ligand-dependent activation of beta-adrenergic G protein-coupled receptors (GPCRs). Here, we uncover an alternate paradigm of GPCR-mediated adipose thermogenesis through the constitutively active receptor, GPR3. We show that the N terminus of GPR3 confers intrinsic signaling activity, resulting in continuous Gscoupling and cAMP production without an exogenous ligand. Thus, transcriptional induction of Gpr3 represents the regulatory parallel to ligand-binding of conventional GPCRs. Consequently, increasing Gpr3 expression in thermogenic adipocytes is alone sufficient to drive energy expenditure and counteract metabolic disease in mice. Gpr3 transcription is cold-stimulated by a lipolytic signal, and dietary fat potentiates GPR3-dependent thermogenesis to amplify the response to caloric excess. Moreover, we find GPR3 to be an essential, adrenergic-independent regulator of human brown adipocytes. Taken together, our findings reveal a noncanonical mechanism of GPCR control and thermogenic activation through the lipolysis-induced expression of constitutively active GPR3.Diabetes mellitus: pathophysiological changes and therap

Feeding L-carnitine to gestating sows alters the insulin-like growth-factor system in cultured porcine embryonic muscle cells isolated from fetal skeletal muscle

The objective was to determine the effects of L-carnitine on cell proliferation and on messenger RNA (mRNA) concentrations in the insulin-like growth factor (IGF) system. Cultured porcine embryonic myoblasts (PEM) were isolated from fetuses at mid-gestation from sows fed a common gestation diet with a 50-g top dress of 0 (control, n = 6) or 100 mg of L-carnitine (n = 6). Proliferation of PEM was evaluated at 36, 48, 60, and 72 h postplating. Real-time quantitative PCR was used to determine growth factor mRNA concentrations in culture. The number of cells/cm2 did not differ (P>0.05) from sows fed either diet, but the number of cells/cm2 increased (P0.05). There was no treatment difference (P>0.05) for the expression of IGF-I or insulin-like growth factor binding protein 5 (IGFBP-5). But PEM isolated from sows fed L-carnitine had decreased (P<0.05) IGF-II, IGFBP-3, and myogenin (61, 59, and 67%, respectively) mRNA concentrations compared with those of controls. These data suggest that L-carnitine influences the IGF system and myogenin, resulting in enhanced proliferation and delayed differentiation of porcine embryonic myoblasts. These results show that L-carnitine plays a role in regulating proliferation and differentiation of cultured orcine embryonic myogenic cells and that etal muscle growth and development could be ncreased by feeding L-carnitine

Salmonella Dublin: a threat to dairy heifer survival and future performance

Salmonella dublin is a bacterium that can have devastating effects in dairy herds. It is most deadly with calves that range in age from 10 days to 5 months. Salmonella dublin is shed from carrier animals through feces, milk, and colostrum and spread by oral ingestion. Clinical signs are not detected easily until after the infection is well established. Calves may suffer from septicemia, diarrhea, fatigue, and unthriftiness. Death is not an uncommon outcome of this disease. Clinical signs of infection in adults may range from none to enteritis or abortion. Combating the disease requires an awareness of the disease, a preventive herd health program, and attention to detail in caring for the newborn calf

Total blood protein as an indicator of colostral sufficiency and morbidity in dairy calves

Total blood protein measured in calves between 1 and 7 days of age is a good indicator of the sufficiency of colostral intake and level of immunity passed to the calf. This measurement can be used to improve calf management strategies and thereby calf performance. Total blood protein concentrations are associated with immunoglobulin absorption in the neonatal calf, which can impact calf morbidity and mortality. Blood protein >5.5 g/dl indicates sufficient immunoglobulin absorption, and blood protein <5.0 g/dl indicates insufficient absorption. Insufficient immunoglobulin absorption increases the risk of calf morbidity and mortality. The dry cow health program, proper collection, and management of colostrum help ensure that quality colostrum is available for the newborn calf. Proper colostrum administration and low-stress calf management also ensure maximal immunoglobulin absorption. Timing of colostral intake affects total blood protein concentrations. The calf’s ability to absorb immunoglobulins is reduced significantly 12 hr after birth. Therefore, it is critical to administer colostrum during the first few hours of life. Total blood protein can be used to determine if the calf has absorbed sufficient immunoglobulins from the colostrum

Ruminal ammonia load does not affect histidine utilization in growing steers

Fermentation of dietary protein in the rumen leads to ammonia absorption, which could impair amino acid utilization in cattle. Our study was conducted to determine the effects of rumen ammonia load on histidine utilization. Six ruminally cannulated Holstein steers (318 lb) housed in metabolism crates were used in a 6 × 6 Latin square design. Treatments were arranged as a 3 × 2 factorial and included: 0, 1.5, or 3 grams/day L-histidine infused abomasally; and 0 or 80 grams/day urea infused ruminally to supply a metabolic ammonia load. As expected, urea infusions increased rumen ammonia and plasma urea concentrations. No change in nitrogen retention, a measure of lean tissue growth, occurred in response to urea. Retained nitrogen increased with histidine supply, and the maximal response occurred with 1.5 grams/day of histidine, suggesting that this amount was near the supplemental requirement. Our research revealed that increases in ammonia load did not demonstrate a metabolic cost in terms of whole body protein deposition, regardless of whether histidine was limiting. Thus, although an excess protein supply may not be economically efficient or environmentally friendly, it does not appear to directly penalize animal performance

Effects of ammonia load on amino acid utilization by growing steers

Ruminally cannulated steers were used in two experiments to study effects of rumen ammonia load on methionine and leucine utilization. All steers were limit-fed a diet based on soybean hulls, received ruminal infusions of volatile fatty acids and abomasal infusions of glucose to provide energy, and received an abomasal infusion containing a mixture of all essential amino acids except methionine in Exp. 1 or leucine in Exp. 2. Treatments were arranged as 3 × 2 factorials and included urea (0, 40, or 80 g/day) infused ruminally and methionine (2 or 5 g/day) infused abomasally in Exp. 1 and leucine (0, 4, or 8 g/day) infused abomasally and urea (0 or 80 g/day) infused ruminally in Exp. 2. In Exp. 1, supplementation with the greater amount of methionine improved retained nitrogen, but urea infusions did not alter nitrogen retention. In Exp. 2, leucine linearly increased retained nitrogen, and urea infusions also increased nitrogen retention. The efficiency of deposition of supplemental methionine ranged between 18 and 27%, whereas that for leucine ranged from 24 to 43%. Increasing ammonia load did not negatively impact whole-body protein deposition in growing steers when either methionine or leucine was limiting