Nutrient Requirements of Beef Cattle: Protein and Metabolic Modifiers - Engormix
All results adhering to the NEW MEET SCORES POSTING GUIDELINES CHAIRS, STATE CHAIRS AND TECHNOLOGY SCORE SUPPLIERS form that the results of the competition will be posted online on their club site or TDNI Boys Team Meet Schedule GV's Medalists Meet: December 8 (Level 4, Silver, Meet Results: Winter Carnival: Brentwood, NH - January Meet Results: TDNI: Springfield, MA – February (levels 5 & 6) Gymshots Photography · International Gymnast Online Magazine · NH Men's Gymnastics. SciELO - Scientific Electronic Library Online (NFCI), total digestible nutrients ( TDNI), as well as DMI and NDFap/kgCP, DMI and Similar results for DM digestibility, NDF, CP, MO, CT and the TDN. The diets were formulated so as to meet the nutritional requirements of animals, maintaining and daily gain of kg/ day.
Meta-regression analysis of literature data based on the dual-labeled urea isotopic approach was used to derive equations to predict urea-N used for anabolism Eisemann and Tedeschi, Data were obtained from nine studies in which the dual-labeled urea technique was used in growing cattle to estimate urea kinetics as described by Lobley et al. Most of the diets were predominantly foragebased, but two experiments included several high-concentrate diets.
Predicted values for UUA were compared with previous estimates of recycled urea NRC, that did not include data on urea production.
6 Microbial Growth | Ruminant Nitrogen Usage | The National Academies Press
Comparison showed a more consistent prediction pattern with the new equation and in general, lower estimates. The proportion of urea entry rate used for anabolism declined as NI increased as was observed previously Reynolds and Kristensen, However, the absolute amount used for anabolism showed a slight increase.
Because of uncertainty in the efficiency of converting total available N in the rumen to RDP, an allowance for urea recycling is not included in the model. Further evaluation of urea recycling, across a wide range of diets, is needed to define the contribution of urea-N recycling to ruminal N requirements and N metabolism.
Compounds that Modify Digestion and Metabolism There are a number of feed additives and other compounds used in beef cattle production to improve animal health and efficiency of nutrient use, increase growth rate, and decrease the environmental impact of beef cattle.
Some additives alter ruminal fermentation, some affect other aspects of GIT function, and some affect post-absorptive metabolism. Additives that alter ruminal fermentation include ionophore antibiotics, poloxalene, plant secondary metabolites, and buffers.
These compounds alter microbial fermentation to improve feed efficiency or prevent or treat digestive disorders such as ruminal acidosis or bloat.
Direct-fed microbials and feed enzymes alter ruminal fermentation or other aspects of gastrointestinal tract function to enhance production efficiency. Ionophores Ionophores are compounds included in diets of growing and finishing cattle to improve feed efficiency and animal health.
They are effective for cattle grazing pasture and confined cattle consuming high-concentrate diets. They shift microbial populations resulting in a shift in short chain fatty acid produced toward greater propionate; decrease deamination of amino acids, decrease methane production, decrease the risk of subclinical acidosis, and decrease bloat.
Ionophores result in improved performance. This adjustment was re-evaluated based on the metaanalysis of Duffield et al. Feed conversion in control cattle also improved over this same time interval consistent with providing diets containing greater net energy concentration.
Across all studies with growing and finishing cattle that were analyzed, monensin decreased DMI by 3. Although not studied to the same degree as feedlot cattle, a similar trend was observed in DMI for cattle fed forage-based diets Bretschneider et al. There was no decrease in predicted DMI when lasalocid or laidlomycin propionate was fed.
Feed conversion feed to gain ratio was improved by 3. Thus, to account for these changes in DMI and the feed: Based on the mode of action of ionophores in the rumen, dietary ME was changed to account for the improvements in ADG and feed efficiency.
The recommendation for laidlomycin propionate is the same as for lasalocid. Implants A variety of anabolic implants has been used to increase the efficiency of beef cattle production since the s. They enhance growth rate, feed efficiency, and lean tissue accretion. Active ingredients include estrogens estradiol, estradiol benzoate, and zeranolandrogens testosterone propionate and trenbolone acetate and progesterone.
Implants can be composed of a single compound or a combination of an estrogen and androgen or an estrogen and progesterone. Implant products are available for use in steers and heifers destined for slaughter. The response is greater when cattle consume diets providing a higher plane of nutrition.
Implants increase both rate of gain and feed intake. Rate of gain is usually enhanced more than intake, and consequently feed conversion is improved. It was concluded NRC,that the effect on nutrient utilization was minimal. As a consequence, their effect on nutrient requirements was accounted for by their effect on protein, fat, and energy accretion, which was taken into account by adjusting slaughter weight at constant finish NRC, ; Tylutki et al.
Most of the increase in weight gain can be accounted for by an increased growth of lean tissue and skeleton.
Intake, digestibility and performance of lambs fed with diets containing cassava peels
The trials included various implant strategies that resulted in greater or lesser effects on BW and carcass characteristics. Fewer implant strategies were evaluated for heifers and they were grouped into only three categories. The summary of Guiroy et al. The coupling of the receptor and G proteins leads to consequent activation of several intracellular signaling pathways associated with receptor binding. These compounds are orally active and increase skeletal muscle growth.
Two of these synthetic compounds, ractopamine hydrochloride and zilpaterol hydrochloride, are approved in the U. The response to these compounds decreases over time and therefore, they are included in the diet for a relatively short time at the end of the feeding period NASEM, Recent meta-analyses of growth responses and carcass characteristics following ractopamine inclusion were reported that included 32 studies using steers Pyatt et al.
Dry matter intake was not affected by ractopamine in either gender, whereas ADG, feed efficiency, dressing percent, and Longissimus muscle area improved. The equations developed by Guiroy et al. Inclusion of zilpaterol increased ADG and improved gain: Zilpaterol increased hot carcass weight, dressing percent, and Longissimus muscle area, while producing less visceral fat, lower marbling, and less fat at the 12th rib in steers Vasconcelos et al.
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Key attributes of zilpaterol are to increase muscle growth and dressing percent. The effect on the carcass is greater than on BW. Zilpaterol alters rate and composition of gain at a lower dose and with a shorter feeding period than ractopamine.
Using the equations of Guiroy et al. All authors read and approved the final manuscript. Acknowledgments The authors are thankful to the Director, National Dairy Research Institute, Karnal for providing the necessary facilities to conduct the experiment. The research work was carried out in the project No. Competing Interests The authors declare that they have no competing interests. Dry matter intake of lactating dairy cattle.
Integration of metabolism and intake regulation: A review focusing on periparturient animals.
Supplementation effect of bypass fat on production performance of lactating crossbred cows. Effects of protected fat supplements on production of early lactation Holstein cows. Milk production, peripartal liver triglyceride concentration and plasma metabolites of dairy cows fed diets supplemented with calcium soaps or hydrogenated triglycerides of palm oil.
Effect of feeding protected fat and proteins on milk production, composition and nutrient utilization in Murrah buffaloes Bubalus bubalis Anim. Effect of supplementing bypass fat prepared from soybean acid oil on milk yield and nutrient utilization in Murrah buffaloes.
Postpartum physiological adaptation in hormones, metabolites and milk production in crossbred cows fed with prilleded fat. Nutritional effects on metabolic profile and early lactation performance of Murrah buffaloes fed diet supplemented with prilledd fat.
Managing Nutrition for Optimal Milk Components. Pennsylvania State University Extension; Breeding and Improvement of Farm Animals. In the evaluation of corn replacement by cassava in the diet of goats, Menezes et al have observed that the digestibility coefficient of DM ranged from In a study assessing the in situ rumen degradability.
On the other hand, DEE showed a growing linear effect with the inclusion of cassava peel. Such behavior may be the result of a higher digestion rate ofEE from cassava peel as compared to other foods present in experimental diets Table 2. A quadratic effect was observed for DNFC, with a maximum value of This can be explained by the fact thatstarch cassava peelis of better digestibility than that of corn.
According to Zeoula et al. A mean value of 0. Corroborating this work, witha study by Faria et al. Feed conversion is defined as the DMI: ADG ratio, representing the efficiency with which the animal converts food in to protein of animal origin.
The mean value found for WCY was The similarity of body weight, associated with a similar age have possibly prevented that the carcass yield was affected; the reason is that, according to Cezar and Sousaamongst the factors intrinsic to animals, body weight and age are probable the ones that most influence the carcass yield.
Lower carcass yield values Revista Brasileira de Zootecnia. Valor nutritivo de dietas contendo raspa integral da mandioca para ovinos confinados. On the estimation of non-fibrous carbohydrates in feeds and diets. Standardization of procedures for nitrogen fractionation of ruminat. Feed Science and Technology. Regulation of forage intake. Forage quality, evaluation and utilization.
Nutrient Requirements of Beef Cattle: Protein and Metabolic Modifiers
American Society of Agronomy, Madison. Gravimetric determination of amylase-treated neutral detergent fiber in feeds with refluxing in beakers or crucibles: Nutrient requirements of sheep. National Academy Press,