Cattle Fed Research Articles

Suspected intoxication by Kikuyu grass (Cenchrus clandestinus) of dairy cattle in the Azores, Portugal

ABSTRACT Case history An outbreak of suspected Kikuyu grass (Cenchrus clandestinus) intoxication among dairy cattle occurred on the island of Terceira in the Azores (Portugal), in October 2022. The animals affected were non-lactating dairy cows and heifers from five small farms grazing (free or tethered) a Kikuyu-dominant pasture. Of the 29 animals exposed, 17 were affected, and eight (five heifers and three adult cows) died, resulting in a morbidity rate of 58%, a mortality rate of 28% and a case mortality rate of 47%. Clinical findings and treatment The clinical signs were non-specific and inconsistent, and included dry faeces, some with dark red blood; apathy and prostration; abdominal dilatation; tachycardia; tachypnoea; pale or jaundiced mucous membranes; sham drinking; sialorrhoea; and moderate to severe dehydration. Symptomatic treatment was provided but was ineffective. Haematology and serum biochemistry revealed an acute inflammatory leukogram, increased alkaline phosphatase (ALP) activity, decreased gamma-glutamyl transferase (GGT) activity, and azotaemia. The most consistent necropsy findings were haemorrhages in the epicardium and endocardium, an enlarged liver with rounded edges, non-perforated abomasal ulcers, and haemorrhagic lesions in the small and large intestines. Histopathology indicated myocarditis, hepatitis, interstitial nephritis, enteritis and colitis. Several fungal species were isolated from grass samples taken from affected pastures including several Fusarium spp., the genus implicated in Kikuyu toxicosis. Immediate removal of the animals from the pasture with Kikuyu was the only measure that prevented new cases and resulted in the recovery of some of the less affected animals. Diagnosis The epidemiological features of this outbreak and the clinical signs and micro– and macroscopic lesions observed were highly suggestive of Kikuyu grass poisoning. Clinical relevance Although the weather conditions varied from other published cases, the grazing conditions (almost exclusive Kikuyu grass) and the post-mortem findings were very similar to those described in the literature, particularly the haemorrhages in the epicardium and endocardium. Kikuyu grass is very invasive and presents many desirable characteristics as cattle feed. Thus, an increase in cases of intoxication may be expected. Practitioners and farmers in areas where Kikuyu grass is abundant should be aware of the potential risks of grazing cattle exclusively on these pastures. They should also be aware of the early and subtle signs of Kikuyu intoxication to allow for timely removal of the animals from pasture.

116 In-situ degradability of hemp (Cannabis sativa L.) plant components in cattle

Abstract The 2014 and 2018 Farm Bills defined hemp (Cannabis sativa L.) as an agricultural commodity and removed it from the controlled substances list, developing a pathway for commercialization and increasing interest in cultivating hemp in the United States. Demand for therapeutic, cannabinoid-based hemp products is increasing, and, as not all of the plant components are utilized for these products, there will likely be significant quantities of hemp by-products created. As these by-products are cellulosic, they may be marketed as livestock feed, especially for ruminant animals. There have been limited studies into hemp as cattle feed. Accordingly, the objective of this study was to determine the in-situ degradability of different hemp components in beef cattle. We conducted an in-situ trial with three ruminally cannulated steers (IACUC #8497) and 16 unique hemp samples: leaves, flower, stalk, or whole plant cultivated with four different seed inoculants. Samples were incubated in the rumen for 0, 4, 6, 12, 24, 48, and 72 h and replicated across each steer. After samples were removed, they were rinsed and analyzed for partial dry matter (DM), DM, organic matter (OM), and crude protein (CP). Solubility fractions [immediately soluble (IS), potentially soluble (PS), and not soluble (NS)], rate of degradation (kd), and rumen degradability was determined for OM and CP. Rate of passage (kp) was set at 4.7%. As there were not differences across seed inoculant method, data were combined across plant components. For OM, the NS fraction was greatest for hemp stalks (12%) and least for leaves (7%). The PS fraction ranged 72-75% across plant components with the least value for stalks and greatest for leaves. Of the PS fraction, ruminal OM degradability was least for stalks (51%) and greatest for leaves (72%). For CP, the NS fraction of hemp stalks (16%) was greater than other fractions, which ranged from 6-8%. The PS fraction was approximately 76% for both whole plant and leaves, a vast majority of which (71-73%) was degradable, indicating these plant components provide a good source of rumen degradable protein. The IS fraction was greatest (20%) for hemp flower. Although hemp flower may be easily digested by ruminants, it does not have practical value because this plant component competes in the human market as the flower contains a high percentage of cannabinoids which have therapeutic properties. Ultimately, our data indicate that hemp leaves have nutritional and practical value as feed for beef cattle and that hemp stalks would likely not be well-utilized as a forage source. Before hemp can be integrated into the beef cattle industry as feed, additional research is required to determine the effects of feeding hemp on animal performance and evaluate uptake and retention of cannabinoids in body tissues.

156 In-situ degradability of hemp (Cannabis sativa L.) plant components in cattle

Abstract The 2014 and 2018 Farm Bills defined hemp (Cannabis sativa L.) as an agricultural commodity and removed it from the controlled substances list, developing a pathway for commercialization and increasing interest in cultivating hemp in the United States. Demand for therapeutic, cannabinoid-based hemp products is increasing, and, as not all of the plant components are utilized for these products, there will likely be significant quantities of hemp by-products created. As these by-products are cellulosic, they may be marketed as livestock feed, especially for ruminant animals. There have been limited studies into hemp as cattle feed. Accordingly, the objective of this study was to determine the in-situ degradability of different hemp components in beef cattle. We conducted an in-situ trial with three ruminally cannulated steers (IACUC #8497) and 16 unique hemp samples: leaves, flower, stalk, or whole plant cultivated with four different seed inoculants. Samples were incubated in the rumen for 0, 4, 6, 12, 24, 48, and 72 h and replicated across each steer. After samples were removed, they were rinsed and analyzed for partial dry matter (DM), DM, organic matter (OM), and crude protein (CP). Solubility fractions [immediately soluble (IS), potentially soluble (PS), and not soluble [NS]), rate of degradation (kd), and rumen degradability was determined for OM and CP. Rate of passage (kp) was set at 4.7%. As there were not differences across seed inoculant method, data were combined across plant components. For OM, the NS fraction was greatest for hemp stalks (12%) and least for leaves (7%). The PS fraction ranged 72-75% across plant components with the least value for stalks and greatest for leaves. Of the PS fraction, ruminal OM degradability was lowest for stalks (51%) and highest for leaves (72%). For CP, the NS fraction of hemp stalks (16%) was greater than other fractions, which ranged from 6-8%. The PS fraction was approximately 76% for both whole plant and leaves, a vast majority of which (71-73%) was degradable, indicating these plant components provide a good source of rumen degradable protein. The IS fraction was largest (20%) for hemp flower. Although hemp flower may be easily digested by ruminants, it does not have practical value because this plant component competes in the human market as the flower contains an increased percentage of cannabinoids which have therapeutic properties. Ultimately, our data indicate that hemp leaves have nutritional and practical value as feed for beef cattle and that hemp stalks would likely not be well-utilized as a forage source. Before hemp can be integrated into the beef cattle industry as feed, additional research is required to determine the effects of feeding hemp on animal performance and evaluate uptake and retention of cannabinoids in body tissues.

76 An in-vitro analysis of hemp as feed for beef cattle

Abstract Hemp, Cannabis sativa L., is a versatile crop that has been cultivated for centuries. Cannabis production had been outlawed in the United States due to concerns related to tetrahydrocannabinol (THC) intoxication. However, recent legislation has declassified hemp as a schedule 1 drug under regulated conditions (i.e., THC < 0.3%). Thus, hemp has been reclassified as an agricultural commodity, and its production for fiber, food, and medicine has increased. Hemp cultivation results in by-products that are not utilized for human needs and have potential as livestock feed, especially for ruminants. Current regulations restrict the use of hemp and its by-products in livestock systems due to the presence of cannabinoids. Thus, research on the nutritional value of hemp for cattle is lacking. The objective of this study was to characterize the nutrient concentrations, in-vitro digestibility (IVD), and cannabinoid concentrations of different fractions of the hemp plant. Procedures involving animals were approved by IACUC at Texas State University (#8497). Four replications of hemp plants of the Cherry Soda varietal were cultivated at Texas State University. Samples were air-dried and fractionated into lower (n = 4), leaves (n = 4), stalks (n = 4), and whole plant (n = 4). Dry matter, organic matter (OM), acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein (CP) were determined. For IVD, samples were incubated in digestion vessels containing buffers and rumen fluid at 39.5°C for 48 h and subsequently analyzed for NDF. Cannabinoid analysis was conducted via high-performance liquid chromatography (HPLC). The OM was in acceptable ranges for each hemp fraction (69-95%). The NDF and ADF were within normal ranges of conventional livestock feeds and forages for most fractions, except hemp stalk (81% NDF, 69% ADF). There was high variability in CP between fractions, with the least concentrations observed in the stalk (4%) and greatest in the flower (25%). Stalks had an IVD of 21%, whole plant of 67%, flower of 87%, and leaves of 93%. Cannabinoids were present in each fraction and especially concentrated in the flower (14%) and depleted in the stalk (0.06%). Flower had THC of 0.56%, while other fractions were less than the 0.3% legal threshold. Similarly, total cannabidiol (CBD) ranged from 0.05-11.4% with the greatest concentrations in the flower and least in the stalk. Our results indicate there is potential for hemp to be integrated into cattle production, especially the leaves. Despite adequate nutritional value, there are practical limitations with feeding hemp flower to cattle. In-vivo trials are needed to assess digestibility and profile cannabinoid metabolism in various tissues before hemp can be integrated into cattle diets.

144 Utilizing invasive pigweed (Amaranthus Spinosus) as a novel methane mitigation strategy in beef cattle feed: A sustainable approach

Abstract By 2050, the US beef industry must produce an extra 40 million tons of beef to satisfy the global demand, while reducing methane (CH4) emissions. This surplus of cattle will be provided mostly by cow-calf operations, which rely primarily on grazing. Those pastures are often infested with weeds such as pigweed (Amaranthus spinosus), one of the most invasive in the US, known for its increased polyphenols concentration. Despite the known effect of polyphenols on CH4 reduction, few studies have explored pigweed as a feed additive. Our objective was to evaluate the effect of in vitro addition of pigweed on ruminal fermentation, digestibility, and CH4 production. We collected ruminal fluid from three American Aberdeen steers (374 ± 21 kg) receiving a backgrounding diet (80:20% corn silage:cotton gin trash, as fed). We incubated (24 h, 39°C) diet (0.7 g) plus the inclusion of 0, 2.5, 5, or 10% (of diet DM) of roots, stems, leaves, seeds, or the whole pigweed plant (WHO). Volatile fatty acids (VFA), CH4 (mmol g-1 organic matter), ammonia, pH, gas, in vitro dry matter, and organic matter digestibility (IVDMD and IVOMD) were determined. Using the MIXED procedure of SAS, data were analyzed as a randomized complete block design with a 5 × 4 factorial arrangement of treatments with plant part (n = 5) and inclusion level (n = 4) as fixed main factors. Incubation and bottle within incubation were random effects. Polynomial orthogonal contrasts were used to determine linear, quadratic, and cubic effects of inclusion level. Plant × level interactions were detected in acetate, propionate, and butyric molar proportion, total VFA, CH4 production, and IVDMD (P < 0.01). Increasing levels of stems increased acetate concentration (P = 0.03), while those from WHO led to a linear reduction of acetate (P < 0.01). The inclusion of 2.5% of leaves, seeds, and WHO increased propionate concentration (P = 0.05), but greater levels decreased it (P < 0.01). Increasing levels of all parts decreased acetate:propionate proportion (P < 0.001). Increasing levels of WHO resulted in a linear reduction of CH4 production (P < 0.05), while increasing inclusion of roots and stems increased CH4 production (P < 0.01). Quadratic reductions in CH4 production were observed after increasing the addition of leaves, seeds, and WHO (P < 0.001). Increasing levels of leaves and roots decreased ammonia concentration (P < 0.01) while stems increased it (P = 0.01). Except for stems and roots, there was a linear decrease in IVDMD with increasing levels of all parts (P < 0.001). The inclusion of low levels of seeds, leaves, and WHO promoted ruminal changes leading to a reduction of CH4 production without significantly compromising the digestibility.

Developments, bottlenecks, and opportunities in seed markets for improved forages in East Africa: The case of Kenya

AbstractBackgroundCattle farming plays a pivotal role in Africa's agricultural and livestock sector, poised for growth due to population expansion and rising per capita consumption of animal‐sourced food. Forages are a primary source of feed for dairy cattle, significantly impacting production costs. While local forage varieties are preferred by dairy farmers, there has been an increase in the adoption of improved forages in recent years. However, the overall adoption rate is still low, for example, due to underdeveloped forage seed markets.MethodsThis study describes the dynamics, challenges, and potential of these markets in Kenya and selected East African countries, focusing on (i) market evolution over the past decade, (ii) forthcoming market prospects, and (iii) bottlenecks and opportunities for improvement. Data were gathered in 2022 through qualitative interviews with stakeholders representing six segments of the forage seed sector across six countries.ResultsWe found a sustained growth of the improved forage seed market in recent years. The main challenges for further growth are high seed prices, regulatory difficulties, and limited producer knowledge.ConclusionsThe findings unveil positive dynamics in the region's forage seed market, fueled by the engagement and determination of stakeholders who recognize the manifold benefits that it holds for both the dairy industry and economic growth. The realization of this market's potential requires addressing prevailing challenges, including elevated seed costs, intricate variety registration processes, and a pervasive lack of awareness among farmers.

Deep learning-based classification of cattle behavior using accelerometer sensors

<span lang="EN-US">The increasing demand for food has led to the adoption of precision livestock, which relies on information and communication technology to promote the best practices in meat production. By automating various aspects of the industry, precision livestock allows for increased productivity, more effective management strategies, and decision-making. The paper proposes a methodology that uses deep learning techniques to automatically classify cattle behavior using accelerometer sensors embedded in collars. The work aims to enhance the efficiency and productivity of the industry by improving the classification of cattle behaviors, which is essential for farmers and barn managers to make informed decisions. We tested three different classification techniques to classify rumination, movement, resting, feeding, salting and other cattle behaviors and we achieved promising results that can contribute to a better understanding and management of cattle behavior in the livestock industry.</span>

Chinese consumer preference for beef with geographical indications and other attributes

As the demand for beef products grows in the Chinese market, understanding consumer preferences for beef, especially those related to quality labelling, is essential. The recent agreement between China and the European Union to promote Geographical Indications (GIs) provides a new insight into preferences for beef with quality labelling. This paper assesses consumer preferences for beef products with GIs and other attributes. A nationwide survey is conducted including 1210 respondents in China by a choice experiment attributing GI label, ‘green’, ‘hazard-free’, and ‘organic’ labels, feeding regimes (grain-fed, grass-fed), country of origin (China, Ireland, Australia, Brazil), and price (30, 40, 80, 100 ¥/500 g). The random parameter logit model with error component reveals that Chinese consumers have a significant preference for grain-fed beef and domestic beef, and they are willing to pay a premium price for GI-labelled beef compared with other attributes. The interaction between GIs and country of origin is included to indicate the positive price impact of GIs on imported beef products. Demographic factors such as place of residence and occupation are found to affect consumer preferences for GIs.

Prevalence of mycotoxins from silage in a small beef cattle feedlot over a storage season: a case study

Challenges exist worldwide for the storage of animal feed, though year-long feeding of livestock is especially difficult in northern climates, including Canada. Usage of silage allows for crops to be harvested at the optimal nutritional value and stored for extended periods in customized storage systems. This case study investigated various feed management practices typical of small beef cattle feedlot farms in Southwestern Ontario, Canada. Crop samples were collected monthly and analyzed for mycotoxins and fungal secondary metabolites by liquid chromatography mass spectrometry (LC-MS/MS). Stored barley contained modest concentrations of deoxynivalenol and related compounds, as well as near trace amounts of fumonisin. Stored hay contained low concentrations of deoxynivalenol and beauvericin from the field. Hot spots of the Penicillium metabolite citrinin were detected after 7–8 months of storage in barley (39.2 ng g−1). Citrinin was also detected after 7–8 months in hay (16.3–17.5 ng g−1) along with the appearance of trace amounts of other storage toxins, including penitrem A (8.84 ng g−1), griseofulvin (34.8 ng g−1) and sterigmatocystin (14.1–261 ng g−1). This case study was a unique opportunity to use ‘citizen science’ to observe the onset of postharvest fungi and associated mycotoxins in various storage conditions allowing for the farmer to make necessary modifications before major problems begin. An improved understanding of the storage conditions that foster fungal growth and mycotoxin production in this working farm led to better agronomic practices, ultimately improving feed quality, livestock health, and profitability.

Handling Agricultural Waste as Alternative Feed in Beef Cattle Business Groups in Baruga Village, Kendari City

UNSULTRA Internal Community Service Activities (PKM-UNSULTRA) carried out by a team of lecturers from the Faculty of Agricultural Technology located in Baruga Village, Kendari City. Introducing how to make cattle feed using agricultural waste feed ingredients using appropriate processing methods in the beef cattle farming business group. Community service activities aim tutilize and apply feed from agricultural waste. Processing in the manufacture of feed from agricultural waste as an alternative feed to replace forage during the dry season. This is intended so that farmers can make their own feed and run their livestock business in a more focused manner. The results of the activity show that there has been an increase in knowledge and skills in better feed processing in the use of agricultural waste into feed for beef cattle as well as business management.

Improving the feeding value of rice straw

For rice producers, removing straw from a field after harvest is important because the material is slow to break down and needs to be gone prior to planting the next season. One option is to bale the straw and use it as a forage supplement for cattle. Although rice straw is a lowcost supplement, it’s also low in forage quality and digestibility. Three trials over a four-year period tested methods to improve rice straw forage quality in the field where it was harvested, and then tested the treatments in cattle feeding trials to assess intake by cattle, performance in weight and size gain, and forage quality. The goal was to find an economical method to improve rice straw feeding value that was also practical to implement for both rice farmers and beef cattle producers. Of the treatments tested, treating traditionally baled rice straw with ammonia gas improved crude protein, intake and cattle performance, compared to untreated straw. The treatment achieved the goals of being easily transported, practical to implement, and cost effective.

Overview of Cyanide Poisoning in Cattle from Sorghum halepense and S. bicolor Cultivars in Northwest Italy.

Sorghum plants naturally produce dhurrin, a cyanogenic glycoside that may be hydrolysed to cyanide, resulting in often-lethal toxicoses. Ruminants are particularly sensitive to cyanogenic glycosides due to the active role of rumen microbiota in dhurrin hydrolysis. This work provides an overview of a poisoning outbreak that occurred in 5 farms in Northwest Italy in August 2022; a total of 66 cows died, and many others developed acute toxicosis after being fed on either cultivated (Sorghum bicolor) or wild Sorghum (Sorghum halepense). Clinical signs were recorded, and all cows received antidotal/supportive therapy. Dead animals were subjected to necropsy, and dhurrin content was determined in Sorghum specimens using an LC-MS/MS method. Rapid onset, severe respiratory distress, recumbency and convulsions were the main clinical features; bright red blood, a bitter almond smell and lung emphysema were consistently observed on necropsy. The combined i.v. and oral administration of sodium thiosulphate resulted in a rapid improvement of clinical signs. Dhurrin concentrations corresponding to cyanide levels higher than the tolerated threshold of 200 mg/kg were detected in sorghum specimens from 4 out of 5 involved farms; thereafter, such levels declined, reaching tolerable concentrations in September-October. Feeding cattle with wild or cultivated Sorghum as green fodder is a common practice in Northern Italy, especially in summer. However, care should be taken in case of adverse climatic conditions, such as severe drought and tropical temperatures (characterising summer 2022), which are reported to increase dhurrin synthesis and storage.

An Evaluation of the Field Efficacy of Tildipirosin for Control of Bovine Respiratory Disease in Feedlot Calves in Bulgaria

Bovine respiratory disease (BRD) is one of the most common and economically important disease affecting feedlot industry throughout the world. The economic significance of this condition are high morbidity and mortality, decreased weight gains, reduced food utilization, low meet quality and additional therapeutic and prophylactic measures. The hypothesis of this study was that the use of metaphylactic protocol based on the risk to develop BRD would reduce morbidity and mortality. For this purpose, the aims of this study were to evaluate the effect of tildipirosin on the incidence of BRD in feedlot cattle. A total of 106 male beef calves were enrolled in the study. Calves were allocated randomly in control group (54 animals) and treatment (52 animals) group. The first group received subcutaneous injection of placebo while the second was treated with SC injection of tildipirosin. The observed BRD incidence was 35.2, and 9.6% for the calves in the control and treatment group, respectively (P = 0.012). These results suggest that the tildipirosin metaphylaxis tend to decrease the incidence of BRD in the first four weeks of the fattening period in beef cattle. In conclusion, metaphylactic protocols, based on the administration of tildipirosin in the high risk period can be used for management of BRD.

Moisture Optimization and Energy Saving Effects of Combined Organic Acid and Surfactant Inclusion in Pelleted Feed Production

The purpose of the present study was to determine the effects of inclusion of an organic acid and surfactant (OS) combination on moisture optimization and energy sparing in the production of pelleted compound feeds for dairy and beef cattle. The trial was carried out in two independent private commercial feed factories (factories A and B) producing cattle feed in pellet form. Each factory produced 21 tons of commercial cattle feed (7 batches; 3 tons per batch); factory A, a dairy feed containing 2620 kcal/kg metabolizable energy (ME) with 18.90% crude protein (CP); and factory B, a fattening feed containing 2550 kcal/kg ME with 13.00% CP. Batches for the treatment groups were prepared by adding 0.5, 1.0 and 1.5 kg/ton of OS (Fylax flow) respectively to these basal feeds in the mixer. The moisture retention capacity during pelleting process of all three OS supplemented feeds increased in comparison to the basal feed, whilst moisture content of the finished feeds and energy consumed for production decreased significantly. It was observed that increasing the OS supplementation to 1.5 kg could further increase the moisture retention capacity and moisture content in pellet production compared to the feeds supplemented with 0.5 and 1.0 kg OS, due to the lower power rating of the equipment. It has thus been concluded that adding 0.5, 1.0 and 1.5 kg of OS to commercial compound feeds for dairy resulted in a profitable production with good moisture optimization and energy savings during pelleting.

Pemanfaatan Ampas Tahu Menjadi Jajanan Kekinian Sebagai Usaha Untuk Pemanfatan Limbah Ampas Tahu Di Kelurahan Lewirato

Despite being rich in protein, fat, and water content, the utilization of tofu dregs remains limited, with entrepreneurs predominantly using it as animal feed, material for making "gembos" tempe, and crackers, which have not significantly contributed to the community's economic welfare. In the Lewirato district, tofu dregs are solely utilized as cattle feed, although its potential to be processed into value-added food products remains largely untapped. Therefore, the objective of this community service initiative is to provide training to the locals on how to process tofu dregs into products such as sponge cakes, okara sticks, and tofu dregs bread with improved packaging and branding. The implementation method encompasses initial surveys, program socialization, training sessions, and evaluation, with the aim of empowering the community to optimize the utilization of tofu dregs as trendy snacks that offer economic value addition.

Crossbreed Dairy Cow Production, Feeding and Management practice at Gidole Town, south Ethiopia

The study aimed to evaluate the production, feeding, and management techniques of Holstein Friesian (HF) crossbred dairy cows at Gidole town, south Ethiopia. Cross-sectional survey involving 60 households selected through systematic random sampling from a total of 150 households with crossbred HF dairy cows in the town. Chemical compositional analysis performed on key feed items collected from the study households. Data analyzed using the Statistical Package for the Social Sciences software. Average daily milk yield was 7.29±0.22 liters, while average lactation milk yield was 1727.73±9.57 liters. The average lactation length was 7.9±1.45 months. While 53.3% of households possessed crossbreed cows with a blood level of 50%, 43.3% had cows with a blood level of 50-75% and 3.3% had cows with a blood level beyond 75%. Crop residue, improved forages (desho, Guatemala, and elephant grass), enset, atella, and salt were the most important cattle feed resources. In the non-conventional diet, atella has the highest crude protein (CP) content (29.24%), followed by elephant grass (18.44%) and teff straw (6.34%). Despite its importance, feed availability remains a challenge in terms of both quality and quantity. To address this, the study recommends strong extension efforts focused on: promoting the use of concentrate feed, developing and utilizing improved forage options and treating crop residues to enhance their quality.
 Keywords: Crossbred dairy cow, Gidole, feed, feeding practices, milk production

Identification and evolution of ICE-PmuST394: a novel integrative conjugative element in Pasteurella multocida ST394.

The emergence of macrolide and tetracycline resistance within Pasteurella multocida isolated from feedlot cattle and the dominance of ST394 in Australia was reported recently. To establish the genetic context of the resistance genes in P. multocida 17BRD-035, the ST394 reference genome, and conduct a molecular risk assessment of their ability to disperse laterally. A bioinformatic analysis of the P. multocida 17BRD-035 genome was conducted to determine if integrative conjugative elements (ICEs) carrying resistance genes, which hamper antibiotic treatment options locally, are in circulation in Australian feedlots. A novel element, ICE-PmuST394, was characterized in P. multocida 17BRD-035. It was also identified in three other isolates (two ST394s and a ST125) in Australia and is likely present in a genome representing P. multocida ST79 from the USA. ICE-PmuST394 houses a resistance module carrying two variants of the blaROB gene, blaROB-1 and blaROB-13, and the macrolide esterase gene, estT. The resistance gene combination on ICE-PmuST394 confers resistance to ampicillin and tilmicosin, but not to tulathromycin and tildipirosin. Our analysis suggests that ICE-PmuST394 is circulating both by clonal expansion and horizontal transfer but is currently restricted to a single feedlot in Australia. ICE-PmuST394 carries a limited number of unusual antimicrobial resistance genes but has hotspots that facilitate genomic recombination. The element is therefore amenable to hosting more resistance genes, and therefore its presence (or dispersal) should be regularly monitored. The element has a unique molecular marker, which could be exploited for genomic surveillance purposes locally and globally.

The use of soybeans in the structure of the ration of high-yielding cows

In the conditions of intensive milk production in order to ensure high productivity and at the same time preserve the general functional state of animal health it is impossible to do without the use of protein-rich grain components in the structure of compound feed. These include soybeans, which in the western region of Ukraine began to be widely used in the production of compound feed for cattle. The percentage of introduction of soybeans into the structure of compound feed is different and for high-yielding cows requires additional study, which explains the relevance of conducting research on its influence on milk productivity, quality indicators of milk against the background of assimilation of the main nutrients of feed. The study was conducted on four groups of Simmental cows, seven heads in each. The rations of experimental cows provided for three levels of provision of protein needs at the expense of soybeans and were balanced in terms of basic nutrients in compliance with the requirements of detailed requirements. The analysis of the feeding conditions of experimental cows showed that the use of heat-treated soybeans in the structure of the ration contributed to a significant increase in milk productivity, as well as quality indicators, the content of dry matter, fat, protein, calcium and phosphorus. A similar pattern was observed in terms of indicators of the intensity of metabolic processes of cicatricial digestion. Thus, a positive effect on the percentage of certain volatile fatty acids, in particular acetic as a precursor of milk fat was noted. An increase was noted in the digestibility indicators of the main nutrients (protein, fat, fiber digestibility coefficients). The positive effect of soybeans on the milk productivity of the experimental cows was also noted by the results of the balance experiment. The nitrogen balance was positive and its use for milk production in cows of the fourth group compared to the control group was 27.4 % higher. A similar trend was observed in the balance of calcium and phosphorus. So, the conducted studies on the study of the productive effect of different amounts of soybeans instead of cereal components in the structure of compound feed on milk productivity give reason to recommend that farms use prepared soybeans in the proportion of 10–15 % in compound feed for high-yielding cows.

Comparative production performance and rumen bacterial diversity of fattening beef cattle supplemented with different levels concentrated feed

The production performance and rumen bacterial diversity were compared for different silage-based diets supplemented with common concentrate or bio-concentrate to develop an alternative of common concentrate for fatten cattle feeding. The daily gain of fattening cattle was increased by 0. 99 kg and 1.04 kg, respectively, when fed with single corn silage or mixed silage-based diet supplemented with bio-concentrate. There was no significant difference in water loss rate and cooked meat rate among groups (P>0.05), but the tenderness of beef in the bio-concentrate group was significantly higher than that in the common concentrate group (P<0.05). There were no adverse effects on beef quality and blood biochemical indexes in each group. Compared with the normal concentrate group, the OTU number and α-diversity index of rumen microorganisms of fattening cattle fed with mixed silage as the basic diet supplemented with bio-concentrate increased significantly. At generic level, the relative abundances of Prevotella, Porphyromonadaceae (unclassified), and Succiniclasticum were increased by adding bio-concentrate in the diets based on mixed silage and single sorghum silage. Relative abundances of Bacteroidetes (unclassified), Ruminococcaceae (unclassified), and Firmicutes (unclassified) decreased. In conclusion, the bio-concentrate might be a better choice than common concentrate for beef cattle breeding.

Rumen ciliates (Ciliophora, Trichostomatia) in Brazilian domestic cattle feeding on diets with crescent urea levels

Since their discovery, rumen ciliates of domestic cattle have been reported from various geographic locations. However, until now there is only one taxonomic inventory of ciliates associated with Brazilian cattle. The present study aimed to assess the community composition, relative abundance, richness, and density of rumen ciliates in Brazilian cattle, whose feeding diets were supplemented with crescent urea levels. Across all treatments analyzed, one subclass, two orders, three families, 11 genera, and 31 species of ciliates were identified. The ciliate community composition and species richness varied among the four treatments used. However, the total ciliate density was not affected by the experimental diets. We described a new entodiniid morphotype, Entodinium caudatum m. orbonuclearis, and recorded Oligoisotricha bubali for the second time in Brazil.