Major health problems and their economic impact on beef cattle under two different feedlot systems in Brazil

Physicochemical Evaluations of Diets, Rumen Fluid, Blood and Faeces of Beef Cattle under Two Different Feedlot Systems

The physicochemical characteristics of diets and faeces were evaluated in combination with data of rumen fluid and blood lactate collected from two distinct feedlot systems in Brazil to understand the causes and correlations to digestive disorders in these production systems. The data were collected during two visits to a finishing system which fed about 80,000 head per year, and four visits to two properties that fed 150 to 180 straight bred Nellore bulls per year to be sold as stud cattle. The findings suggest that ruminal acidosis occurred when there was high intake of starch-rich concentrate, and that subacute rumen acidosis (SARA) most likely occurred in situations where more than 4% of faecal dry matter was excreted as particles larger than 4 mm. The latter were associated with diets having less than 15% of particles smaller than 8 mm and faecal pH under 6.30. It is concluded that ancillary tests, such as ruminal and faecal pH, and particle size distribution in the faeces, can potentially be used in combination with information on diet nutritional composition and a series of best practice management protocols to increase not only animal productivity but to reduce the risks of SARA and ensure the welfare of animals.

Influence of Phytogenic Feed Additive on Performance of Feedlot Cattle

This study evaluated the influence of a blended phytogenic feed additive on feed intake, feeding behavior, nutrient digestibility, and growth performance during feedlot adaptation, early, and late finishing periods as well as carcass traits. Twenty-six crossbred F1 Angus × Nellore bulls (19 mo ± 4 d) were housed in individually pens and fed a high-forage receiving diet for 7 days. At the end of the receiving period, bulls were weighted [initial shrunk body weight (SBW) 363 ± 20 kg], blocked by SBW and randomly assigned to two treatments; Control: without any additive or PHY: 150 ppm of a phytogenic feed additive fed throughout the adaptation and finishing phases. Bulls were transitioned through four steps over 18 days to a high-grain finishing diet (as % DM, 64% rehydrated corn grain silage, 19% corn gluten feed, 13% sugar cane bagasse and 4% minerals, urea, and vitamins mix). The finishing phase lasted 68 days, with mid-point measurements dividing early and late finishing period. The PHY group DMI was greater during adaptation and late finishing periods (P < 0.05), with a tendency during early finishing period (P = 0.06). Number of daily meals was similar between treatments (P = 0.52), but an increased meal length was noted for PHY group (P < 0.05), which contributed to their greater DMI. Diet digestibility remained similar between groups during the finishing periods (P > 0.1). Ruminitis scores were low and liver abscess similar between treatments. Final SBW tended to be higher (P = 0.09) and hot carcass weight was greater for the PHY group (P < 0.05), with no differences on dressing percentage, ribeye area and marbling score. In conclusion, the PHY treatment had positive effects on intake and carcass weight, without increasing metabolic disorders.

Bovine respiratory disease in Brasil: a short review

The bovine respiratory disease (BRD) complex is a multifactorial and multietiological disease entity described in all geographic regions of Brazil. This brief review discusses aspects related to epidemiology, etiologic agents, clinical and pathological manifestations, and challenges in the diagnosis of BRD in Brazil. The main infectious disease agents associated with respiratory outbreaks in cattle from Brazil are bovine alphaherpesvirus type 1, bovine viral diarrhea virus, bovine respiratory syncytial virus, and Mycoplasma bovis. Ovine gammaherpesvirus-2 and HoBi-like pestivirus have been associated with the development of pneumonia in adult cattle and calves, respectively in Brazil, and should be considered as possible causes of BRD. Additionally, studies using epidemiological data, histopathological and molecular associations with morbidity and mortality should be carried out in Brazil, to demonstrate the real impacts of BRD on livestock.

Assessment of Rumen Mucosa, Lung, and Liver Lesions at Slaughter as Benchmarking Tool for the Improvement of Finishing Beef Cattle Health and Welfare

Abattoir post-mortem inspections offer a useful tool for animal disease surveillance. The present cross-sectional study aimed at assessing the prevalence of rumen mucosa, lung, and liver lesions in 153 randomly selected batches of finishing beef cattle through a post-mortem inspection at the abattoir. At least 15 animals per batch were inspected at slaughter by two veterinarians for a total of 2,161 animals (1,376 bulls; 785 heifers) coming from 80 Italian commercial farms. Rumens were inspected by recording as binary variables (presence/absence) signs of hyperkeratosis, ruminitis, ulcer, and star scars. Similarly, lungs were inspected for signs of pneumonia and livers for signs of lipidosis, abscesses, and/or adherence. Hyperkeratosis of the mucosa and signs of ruminitis were detected in 58 and 30% of the inspected rumens, respectively. Ruminal star scars were more prevalent in bulls than in heifers (18 vs. 11%; P < 0.05). Signs of severe pneumonia were observed in 10% of the lungs; abscess and/or adherence in 4% of the livers. Hyperkeratosis of rumen mucosa was correlated to signs of ruminitis, and signs of ruminitis were correlated to star scars. No correlations were found between hepatic lesions and any other rumen or lung disorders. The wide variability observed among batches for the prevalence of specific lesions suggested the development of a benchmarking system to provide feedback to the farm veterinarians, as these lesions can be reflective of a subclinical disease status not easy to be detected in the live animal. Quartiles of the batch prevalence of rumen, lung, and liver alterations (if ≥1%) were calculated as a benchmarking tool, and third quartile value was proposed as an alarm threshold for each lesion. The use of the benchmarking system could allow to allocate each inspected batch to a specific "health class." Critical batches with a prevalence above the alarm threshold for a given lesion should be reported to veterinarians of the origin farms where actions should be taken in order to identify and lower the risk factors for that specific health issue. Knowledge of post-mortem inspection data along with the implementation of the proposed benchmarking system should help farm veterinarians to improve herd management from a health and welfare perspective.

Strategic supplementation of growing cattle on tropical pastures improves nutrient use and animal performance, with fewer days required on the finishing phase

Context Cattle grazing tropical forages usually perform below genetic potential due to limited nutrient intake. Aims Four experiments were conducted to evaluate supplementation strategies on performance and metabolism of cattle grazing intensively managed marandu palisade grass (Urochloa brizantha). Methods Experiment 1 evaluated the average daily gain (ADG) of 72 young bulls (222 ± 25 kg bodyweight, BW) grazing palisade grass and supplemented (22% crude protein, CP) at 0.0%, 0.3%, 0.6% and 0.9% BW, and their ADG during the feedlot finishing phase. Experiment 2 evaluated the ADG of 80 bulls (240 ± 18 kg BW) grazing palisade grass and supplemented with energy (11.3% CP) or three protein sources (≈20.5% CP) at 0.6% BW. Experiment 3 investigated intake, rumen parameters and digestibility of nutrients in fistulated steers (410 ± 8.6 kg BW) fed an energy supplement, that is, ground corn, at 0.0%, 0.3%, 0.6% and 0.9% BW, with a parallel in vitro study of fermentation kinetics (Experiment 4). Key results Increased levels of supplementation resulted in linear increases (P &lt; 0.05) in ADG, stocking rate (SR) and in BW gain per area. There were no differences (P &gt; 0.05) in ADG, SR and BW gain per area among supplemental sources of protein or the energy supplement. Increasing energy levels caused a linear decrease (P &lt; 0.05) in forage intake and grazing time and a linear increase (P &lt; 0.05) in total dry matter and digestible-nutrient intakes, but did not affect (P &gt; 0.05) fibre degradability. Corn supplementation also caused a linear decrease (P &lt; 0.05) in acetate:propionate ratio, in ruminal ammonia-N and in N excretion, and a linear increase (P &lt; 0.05) in rumen propionate concentration, in microbial synthesis and in N retention. The supplementation increased BW at the start of the feedlot phase, resulting in similar hot carcass weights with fewer days on feed and no effects on meat quality. Conclusions Overall, despite the source utilised, supplementation increased ADG, SR and BW gain per area, with fewer days being required on the finishing period. Implications Having adequate supplementation strategies in place will help producers increase the efficiency of their systems.

High-density diet improves growth performance and beef yield but affects negatively on serum metabolism and visceral morphology of Holstein steers

The objective of this study was to evaluate the effect of different dietary densities on growth performance, carcass characteristics, meat quality, serum metabolism, ruminal papillae morphology and liver injuries of steers. For this purpose, a total of eighteen Holstein steers were randomly fed one of the three diets: high energy and protein diet (H), standard energy and protein diet (C), and low energy and protein diet (L) for 11 months fattening with three-step finishing strategy. Steers fed with H diet had higher (p < .05) average daily gain, feed efficiency, hot carcass weight, serum aspartate aminotransferase to alanine aminotransferase ratio, and monounsaturated fatty acids along with continuous low ruminal pH value, severer hepatic steatosis and ruminal papillae parakeratosis. Meanwhile, steers fed L diet increased the proportion of C20:0, C22:6n-3, saturated fatty acids and n-3 polyunsaturated fatty acids along with lower n-6 to n-3 ratio in longissimus dorsi muscle as compared to that of steers fed H diet. Dietary densities did not influence (p > .10) proximate nutrients and sensory characteristics of beef. The present study indicates that Holstein steers could achieve better growth and carcass performance under high-density diet, whereas they are under threat of visceral injuries and metabolic disorders. This study gives comprehensive relationship between productivity and animal health and suggests that a proper diet should be adopted for fattening Holstein steers in consideration of both beef quality and quantity and animal health.