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

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

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 energy source on methionine utilization by growing steers

We evaluated the effect of energy source on amino acid utilization in growing steers. Ruminally cannulated Holstein steers (372 lb) were limit-fed (4.2 lb/day dry matter) a diet based on soybean hulls. A 2 × 5 factorial arrangement of treatments was used: 0 or 3 grams/day of methionine and five sources of energy. The energy sources evaluated were infused in amounts of 1.3 Mcal ME/day and included: control (none), glucose (0.79 lb/day), fat (0.33 lb/day), acetate (0.85 lb/day), and propionate (0.59 lb/day). Acetate and propionate were infused continuously into the rumen, whereas glucose and fat were infused into the abomasum. Nitrogen balance was increased by methionine supplementation, indicating that this amino acid limited protein deposition. Energy supplementation also increased nitrogen balance, with or without supplemental methionine, without differences among energy sources. The results of our study suggest that amino acid utilization by growing steers is improved by energy supplementation, regardless of the source of energy

Effects of four soybean meal products on lactational performance of dairy cows

Dairy Research, 2006 is known as Dairy Day, 2006Thirty-two multiparous Holstein cows (152 days in milk, producing 90 lb/day of milk at the beginning of the study) were used in a 4 × 4 Latin square design with 28-day periods to investigate cow responsiveness to supple-mental ruminally undegraded protein from 4 soybean meal products. The 4 products were: solvent soybean meal (SSBM), expeller soy-bean meal (ESBM), lignosulfonate-treated soybean meal (LSBM), and SSBM treated with 0.05% baker’s yeast and toasted at 212ºF (YSBM). Diets were formulated by substitut-ing all SSBM and part of ground corn with YSBM, ESBM, or LSBM to yield isonitroge-nous diets. Diets were formulated to provide adequate ruminally degraded protein, but defi-cient ruminally undegraded protein and me-tabolizable protein supplies. No differences among dietary treatments were observed for dry matter intake, body weight gain, milk and component yields, or efficiency of milk pro-duction. Lack of response to changes in soy-bean meal source was likely because of ade-quate ruminally undegraded protein and me-tabolizable protein supply by all diets

Postpartum injection with vitamin E and selenium failed to improve the performance of Awassi ewes and their lambs

Abstract and Keywords in English and French. Published on the web March 2015The objective of this study was to investigate the effect of vitamin E and Se injection of nursing Awassi ewes on the performance of ewes (body weight change, milk yield, and composition) and their lambs (growth rate and weaning weight). Twenty-eight Awassi ewes were randomly assigned upon lambing to one of two groups; Control (n=13) and Inject (n=15), where ewes received 0 (control) or 15 plus 0.05 mg kg−1 BW of vitamin E and Se, respectively (inject). Intramuscular injections were given at 1 and 4 wk postpartum. Body weight (BW) of ewes and their lambs were recorded at lambing and at 2, 4, 6, and 8 wk postpartum. Milk yield and composition were measured at 2, 4, and 6 wk postpartum and somatic cell count (SCC) was evaluated weekly (from lambing through 8 wk). Injecting nursing ewes with vitamin E and Se had no effects (P≥0.10) on BW change of ewes, milk yield and composition, composition yields, or milk SCC. Injecting nursing ewes with vitamin E and Se had no significant effects (P≥0.29) on weaning weight, BW gain, or growth rate of their lambs. Under conditions similar to the current study, injecting nursing Awassi ewes with vitamin E and Se at 1 and 4 wk postpartum was not effective in improving the performance of ewes and their suckling lambs. Such observations could be attributed to the time of supplementation (pre- or post-partum) and/or the adequate basal vitamin E status in ewes. = L’objectif de cette e´tude e´ tait d’e´valuer les effets d’injections de vitamine E et de se´ le´nium (Se) dans des brebis Awassi qui allaitent sur la performance de ces brebis (changement de poids corporel, production de lait et composition du lait) et de leurs agneaux (taux de croissance et poids au sevrage). Vingt-huit brebis Awassi ont e´ te´ assigne´es ale´atoirement a` l’un de deux groupes apre` s l’agnelage ; te´moin (n 13) et Inject (n 15), ou` les brebis ont rec¸u 0 (te´moin) ou 15 plus 0,05 mg/kg de poids corporel de vitamine E et de Se, respectivement (Inject). Les injections intramusculaires ont e´ te´ effectue´es 1 et 4 semaines post-partum. Les poids corporels (BW « body weight ») des brebis et des agneaux ont e´te´ enregistre´s a` l’agnelage ainsi qu’a` 2, 4, 6, et 8 semaines post-partum. La production de lait et sa composition ont e´ te´ mesure´es a` 2, 4, et 6 semaines post-partum et la nume´ration des cellules somatiques (SCC « somatic cell countt ») a e´te´ e´value´ de fac¸on hebdomadaire de l’agnelage jusqu’a` 8 semaines post-partum. Injecter la vitamine E et le Se dans les brebis qui allaitent n’a pas eu d’effet (P]0,10) sur le changement de BW des brebis, la production ou la composition du lait, les rendements de composition ou les SCC du lait. L’injection de vitamine E et de Se dans les brebis qui allaitent n’a pas eu d’effet significatif (P]0,29) sur le poids au sevrage, le gain de BW ou le taux de croissance de leurs agneaux. Sous des conditions similaires a` celles de la pre´sente e´tude, l’injection de vitamine E et de Se aux brebis Awassi qui allaitent aux semaines 1 et 4 post-partum n’e´ tait pas efficace pour ame´ liorer la performance des brebis ni de leurs agneaux de lait. Ces observations peuvent eˆ tre attribue´es au temps de supple´mentation (pre- ou post-partum) et/ou le niveau basal ade´quat en vitamine E chez les brebis.M. S. Awawdeh, A. Q. Talafha, and B. S. Obeida

Evaluation of ruminal degradability and lysine bioavailability of four soybean meal products

Dairy Research, 2006 is known as Dairy Day, 2006Evaluations of four soybean meal (SBM) products were conducted. The products were: solvent SBM (SSBM), expeller SBM (ESBM), lignosulfonate-treated SBM (LSBM), and SSBM treated with 0.05% Baker’s yeast and toasted at 212ºF (YSBM). In situ ruminal degradations of YSBM and LSBM were slower than those of SSBM or ESBM; thus, ruminally undegraded protein contents of YSBM and LSBM were greater than those of SSBM or ESBM. The ruminally undegraded protein of all SBM products had similar small intestine digestibility when as-sessed by susceptibility to enzymatic digestion in vitro. Available lysine contents, estimated chemically or using standard chick growth assay, were less for YSBM and LSBM than for SSBM or ESBM, suggesting deleterious effects of processing on lysine availability in those products

Insulin-like growth factor and growth hormone receptor in postpartum lactating beef cows Fator de crescimento semelhante à insulina e receptor do hormônio do crescimento no pós-parto de vacas de corte

The objective of this study was to evaluate the plasma concentrations of insulin-like growth factor-I (IGF-I), and the mRNA hepatic expression of IGF-I and of the growth hormone receptors GHR and GHR 1A, in postpartum beef cows. Four Angus and four crossbred (Angus x Nelore) postpartum suckled beef cows were used. Liver and blood samples were collected every 10 days, from calving to 40 days postpartum, for gene expression and for &#946;-hydroxybutyrate and IGF-I assays, respectively. Samples for progesterone assay were collected every other day, from day 10 to 40 postpartum. Three cows ovulated before 40 days postpartum. IGF-I concentration was higher in Angus x Nelore than in Angus cows. There was no difference in the expression of GHR, GHR 1A and IGF-I according to breed or ovulatory status. IGF-I concentrations were higher in crossbred cows, but have not changed according to postpartum ovulatory status. Moreover, changes in postpartum IGF-I concentrations are not associated with changes in liver GHR, GHR 1A and IGF-I mRNA expression in either breed.<br>O objetivo deste estudo foi avaliar as concentrações plasmáticas do fator de crescimento semelhante à insulina tipo I (IGF-I) e a expressão hepática de mRNA de IGF-I e dos receptores do hormônio de crescimento GHR e GHR 1A, no pós-parto de vacas de corte. Quatro vacas Angus e quatro mestiças (Angus x Nelore) lactantes foram usadas durante o período de pós-parto. As coletas de tecido hepático e de sangue foram realizadas a cada dez dias, do parto até 40 dias pós-parto, para a avaliação da expressão gênica, e análise de &#946;-hidroxibutirato e IGF-I, respectivamente. As amostras para análise de progesterona foram coletadas a cada dois dias, dos dez aos 40 dias pós-parto. Três vacas ovularam antes dos 40 dias pós-parto. A concentração de IGF-I foi maior em vacas Angus x Nelore do que em vacas Angus. Não houve diferença na expressão hepática de GHR, GHR 1A e IGF-I de acordo com a raça ou com a ovulação. As concentrações de IGF-I foram maiores em vacas cruzadas, e não mudaram com o status ovulatório pós-parto. Além disso, as mudanças observadas na concentração de IGF-I, durante o período pós-parto, não estão associadas a alterações na expressão hepática de mRNA de GHR, GHR 1A e IGF-I, em nenhuma das duas raças