Cattle Diets Research Articles

Stable isotopes of C and N differ in their ability to reconstruct diets of cattle fed C3–C4 forage diets

Stable isotopes are useful for estimating livestock diet selection. The objective was to compare δ13C and δ15N to estimate diet proportion of C3–C4 forages when steers (Bos spp.) were fed quantities of rhizoma peanut (Arachisglabrata; RP; C3) and bahiagrass (Paspalumnotatum; C4).Treatments were proportions of RP with bahiagrass hay: 100% bahiagrass (0%RP); 25% RP + 75% bahiagrass (25%RP); 50% RP + 50% bahiagrass (50%RP); 75% RP + 25% bahiagrass (75%RP); and 100% RP (100% RP). Feces, plasma, red blood cell (RBC), and hair were collected at 8-days intervals, for 32 days. Two-pool mixing model was utilized to back-calculate the proportion of RP based on the sample and forage δ13C or δ15N. Feces showed changes using δ13C by 8 days, and adj. R2 between predicted and observed RP proportion was 0.81 by 8 days. Plasma, hair, and RBC required beyond 32-days to reach equilibrium, therefore were not useful predictors of diet composition during the study. Diets were best represented using fecal δ13C at both 8-days and 32-days. By 32-days, fecal δ15N showed promise (R2 = 0.71) for predicting diet composition in C3–C4 diets. Further studies are warranted to further corroborate fecal δ15N as a predictor of diet composition in cattle.

Prediction of Indirect Indicators of a Grass-Based Diet by Milk Fourier Transform Mid-Infrared Spectroscopy to Assess the Feeding Typologies of Dairy Farms.

Simple SummaryThe dairy industry is interested in developing a detection tool for milk produced from pasture to certify the protected designation of origin of certain dairy products. As the cattle’s grazing influences the milk composition, the milk mid-infrared (MIR) spectra will be modified. Therefore, this study aims to develop a predictive model allowing one to use milk MIR spectrometry to classify milk as produced from a cattle diet either based on grass or not. To achieve this objective, the collection of grazing calendars from farms is needed. Unfortunately, this is hardly possible, as this information is rarely recorded. Therefore, the innovation of this research consists of using the usual farming practices developed in the southern part of Belgium combined with a large-scale milk database containing 48 milk composition-related traits. Indeed, in this geographical area, the cows are mainly on pasture between April and September. Therefore, the month of testing can be considered indirect information about their feeding. The developed models were able to distinguish with a precision of around 90% the supposed grass-based diet. Therefore, the probability of belonging to the GRASS class could be used in a tool counting the number of grazing days to confirm the labeling of dairy products.This research aims to develop a predictive model to discriminate milk produced from a cattle diet either based on grass or not using milk mid-infrared spectrometry and the month of testing (an indirect indicator of the feeding ration). The dataset contained 3,377,715 spectra collected between 2011 and 2021 from 2449 farms and 3 grazing traits defined following the month of testing. Records from 30% of the randomly selected farms were kept in the calibration set, and the remaining records were used to validate the models. Around 90% of the records were correctly discriminated. This accuracy is very good, as some records could be erroneously assigned. The probability of belonging to the GRASS modality allowed confirmation of the model’s ability to detect the transition period even if the model was not trained on this data. Indeed, the probability increased from the spring to the summer and then decreased. The discrimination was mainly explained by the changes in the milk fat, mineral, and protein compositions. A hierarchical clustering from the averaged probability per farm and year highlighted 12 groups illustrating different management practices. The probability of belonging to the GRASS class could be used in a tool counting the number of grazing days.

Invited Review: Use of byproduct feeds in southeastern US beef production systems

Byproduct feeds are important in beef cattle feeding systems in the southeastern United States. This article discusses the evolution of a feed from a waste material to a coproduct, presents a current understanding of several important byproducts, and details sweetpotatoes and associated byproducts as an example of a potential feed source that needs continued development. Applied research and outreach results are presented to support the use of byproducts currently in widespread use in the region. Practical advice is offered to readers based on 32 yr of experience working with farmers on byproduct-based diets for stocker cattle and brood cows. There are several well-established byproduct feeds, including soybean hulls, corn gluten feed, distillers grains, and wheat middlings, that have been the subject of a great deal of research and development. Many other potential feed sources remain as waste materials or waste products awaiting more research and development to help them evolve into well-accepted feeds. Nutritionists need to understand the characteristics and limitations of byproducts available in their area. Working with producers to set up effective feeding programs that allow them to make quick decisions on ingredient purchasing and adapting to disruption in supply will be critical. Although many feeds appear valuable “on paper” using the Petersen method, factors that influence their usefulness, including the presence of contaminants or antinutritional factors, high moisture content, and imbalance of key minerals, must be considered in the development of an effective feeding program.

Smallholder farmers’ intention to use insect-based feed in dairy cattle diet in Kenya

Smallholder farmers’ intention to use insect-based feed in dairy cattle diet in Kenya

Cotton gin byproduct: Effects on feed intake, quality, and safety for use in diets of gestating beef cows

The effects of cotton gin byproduct processing and feed safety characteristics are not well defined in beef cattle systems. Our objective was to determine the effects of feeding loose or baled cotton gin byproduct on animal performance and safety of use in beef cattle diets. Twenty-four nonlactating, crossbred cows and heifers (average BW = 613 ± 77 kg) were assigned to 1 of 2 treatments: ad libitum (1) baled cotton gin byproduct or (2) loose cotton gin byproduct. Animal BW and BCS were collected at d 0, 30, and 60 of the study. Jugular blood samples were collected weekly during the trial and again at 30 and 60 d after the study to monitor hematologic responses due to consumption of cotton gin byproduct containing defoliant residue (4.84 and 1.98 mg/kg tribufos for baled and loose, respectively). Cattle consuming loose cotton gin byproduct had greater (P < 0.0001) daily DMI (2.0% of animal BW) than those consuming baled byproduct (1.8% of animal BW). Cattle gained BW and maintained BCS across treatments during the study. White and red blood cell count, hematocrit, and hemoglobin concentrations were within the acceptable range for normal health conditions in beef cattle, and animals displayed no clinical symptoms of altered neurological status due to consuming gin byproduct. Results indicate that cotton gin byproduct in either loose or baled form can be used to maintain nonlactating, bred cows with additional supplementation during a short-term feeding period (60 d).

Invited Review: Using whole cottonseed and cotton harvest residue in southeastern US beef cattle diets: Quality, intake, and changes in feed characteristics

Cotton ( Gossypium sp.) is grown on over 4.5 million hectares in the United States annually. This article provides an overview of cotton industry changes and their influence on whole cottonseed and cotton residue quality and use in beef cattle operations in the southeastern United States. Whole cottonseed may vary depending on cotton growing and harvest conditions, seed composition, and ginning technologies. Most cottonseed is hand fed to beef cattle at a set feeding rate to control fat intake. However, there is variation in the literature in on-farm cottonseed feeding strategies and potential use of whole cottonseed in beef bull diets. Cotton residues are often used as a roughage alternative. Strategies to expand the use of cotton residues include integrated crop-livestock systems, gin byproduct baling applications, and evaluation of chemical residues to determine feeding safety. Periodic characterization of seed protein, fat, and gossypol can refine beef cattle feeding strategies. Grazing cotton field residue can reduce hay needs in beef cattle diets. There is limited information on animal growth performance, health, and safety of beef cattle fed cotton residues, which may potentially contain detectable levels of pesticides or herbicides. Use of whole cottonseed and cotton residues benefits both the cotton and beef cattle industries. Future research to more closely mimic on-farm beef nutritional management strategies may expand the use of whole cottonseed as a supplement. Quality evaluation of cotton byproducts ensures greater accuracy in ration development and may help elucidate threshold values for establishing safety of use.

Native and no-native herbivorous relationships have mutual benefit: Lepus flavigularis case

Lepus flavigularis is an endemic leporid from southeastern Oaxaca, México, listed as “endangered” under Mexican law and the IUCN Red List. The main threat to the species is severe habitat fragmentation due to human activities. The jackrabbit shares the grasslands with cattle (Bos taurus), but the trophic interaction between these herbivores is unknown. This study aimed to determine the seasonal diet of Lepus flavigularis and cattle, to identify the possible dietary overlap between these mammals. The study zone covers an area around the locality of Santa María del Mar in Oaxaca, southern México. Plant species were identified using linear transects, and vegetation cover was also estimated using circular plots. Throughout the study fresh L. flavigularis and B. taurus fecal samples were collected, which were processed using the microhistological technique to determine the seasonal botanical composition of diets from the two species. Twenty-three plant species were recorded in the diet of L. flavigularis and 29 species in the diet of B. taurus. Both herbivores fed primarily on Poaceae species throughout the year (L. flavigularis: dry season (ds) = 79.79 %, wet season (ws) = 91.54 %; B. taurus: ds = 78.02 %, ws = 84.63 %) despite the significant difference in the availability of plant species between seasons. No significant differences were found in the seasonal composition of the diet between the two species. Twelve plant species were consumed by both herbivores during the two seasons. The dietary overlap between the two species was high for both seasons (ds Ojk = 0.7311, ws Ojk = 0.8459). Trophic niche breadth was low for both species, with a high dietary overlap. We recorded low seasonal use values for L. flavigularis and B. taurus when compared to forage availability. Low trophic niche breadth and high dietary overlap between the two herbivores suggest forage resources competition. However, we expect that jackrabbits benefit from cattle presence, as long as the stocking rate does not increase. Furthermore, B. taurus grazing reduces height, cover, and density of vegetation, which could help L. flavigularis to avoid predators.

Inclusion of Grape Pomace in Finishing Cattle Diets: Carcass Traits, Meat Quality and Fatty Acid Composition.

Simple SummaryGrape pomace, a by-product of winemaking, could be used as feed for beef cattle as it provides essential nutrients like fiber and protein. Grape pomace also contains bioactive compounds like condensed tannins, which have been shown to improve meat quality primarily in lambs. Since this information was still lacking, the present study evaluated the effects of feeding a high amount of grape pomace to finishing cattle on quality attributes (e.g., shelf life) and the fatty acid composition of beef. Feeding a high amount of grape pomace to finishing cattle reduced lipid oxidation and increased the meat content of several fatty acids linked to positive health outcomes in humans (e.g., total polyunsaturated fatty acids). These findings suggest that dietary inclusion of grape pomace in finishing cattle diets could enhance the sensory quality of beef and the health value of beef lipids.Because of its high content of polyphenolic compounds, dietary inclusion of grape pomace (GP) in finishing cattle diet could possibly enhance product quality and the health value of beef lipids. Therefore, the aim of this study was to evaluate the effects of feeding a high amount of grape pomace in finishing cattle diets on carcass traits, product quality, and fatty acid (FA) composition of beef. Jersey × Holstein crosses (n = 24) were fed either a typical finishing diet (CON) or a finishing diet containing 58% grape pomace (DM basis; HGP). Following the feeding period, animals were harvested, and carcass traits measured. Longissimus lumborum (LL) and semimembranosus (SM) muscle were then collected from each carcass for sensory quality evaluation and FA profile analysis. Hot carcass weight, backfat thickness, and preliminary and final yield grades were greater (p ≤ 0.04) for CON than HGP steers. However, there was no diet effect on rib eye area (REA), kidney, pelvic, and heart (KPH) fat, and marbling. Feeding the HGP compared to CON diet reduced lipid oxidation of LL and SM steaks over time; the malondialdehyde (MDA) concentration, which did not differ on d 0 and 2 of 8-d simulated retail display, was lower on d 4, 6 and 8 for HGP than CON steers (treatment × day of simulated display interaction; p < 0.01). Brightness (L* values) and redness (b*) were greater for LL steaks from HGP than CON steers on most days of simulated display (treatment × day of simulated display interaction; p < 0.01). In addition, the LL and SM muscle content of several FA linked to positive health outcomes in humans including 18:2 n-6, 18:2 c9t11, total conjugated linoleic acid (CLA) and total polyunsaturated fatty acid (PUFA) was also greater (p ≤ 0.02) for steers fed the HGP compared to the CON diet. In summary, current findings suggest that although it could possibly limit growth performance, feeding a high amount of grape pomace to finishing cattle could enhance both the sensory quality and the health value of beef lipids, which are key in increasing consumer acceptability of beef.

Feed utilization efficiency and ruminal metabolites in beef cattle fed with cassava pulp fermented yeast waste replacement soybean meal

The purpose of this study was to see how substituting cassava pulp fermented yeast waste (CSYW) for soybean meal (SBM) in a concentrate affected feed intake, digestibility, and rumen fermentation in Thai native beef cattle. In this study, four male Thai native beef cattle with an average age of 15.0 ± 25.0 months and body weights of 140 ± 5.0 kg were used. The experimental design was a 4 × 4 Latin squared design, with dietary treatments of CSYW replacing SBM at 0, 33, 67, and 100% in the concentrate mixture. It was discovered that the presence of CSYW had no negative impact on feed intake, nutritional intake, or apparent digestibility (p > 0.05). CSYW had no significant effects on ruminal pH or temperature (p > 0.05). When the amount of CSYW in the diet increased, the rumen ammonia–nitrogen concentration increased (p < 0.05). Blood urea nitrogen was not affected by CSYW (p > 0.05). The total bacterial population increased when the diet's CSYW amount was increased (p < 0.05). Feeding CSYW to beef cattle had no influence on total volatile fatty acid, acetic acid (C2), or butyric acid (C4) proportions (p > 0.05). The concentration of propionic acid (C3) and the C2:C3 ratio increased when the amount of CSYW in the diet was increased (p < 0.05). In conclusion, CSYW can completely replace SBM in a concentrate diet for beef cattle with no adverse effects on feed utilization or rumen fermentation while the total bacterial population and C3 concentration increase.

LECITHIN-CONTAINING FEED ADDITIVE IN THE DIETS OF YOUNG CATTLE

The negative impact of a complex of technological stress factors on the body of young animals determines the use of new biologically active substances in diets that can prevent their adverse effects. Lipids, which are the most concentrated source of energy, can become an alternative to feed antibiotics as growth promoters. The article contains materials of the study of the effectiveness of using different dosages of the new feed additive “Lecithin C” in diets of young cattle. Studies have shown that the&#x0D; use of the feed additive in the compound feed concentrate KR-3 in amounts of 6.5 g, 13.0 and 19.5 g per head per day contributes to an increase in dry matter intake by 1.9-7.5% and metabolizable energy by 2.2-6.5%, increases average daily productivity, provides a reduction in the cost of feed consumed per 1 kg of gain, and the cost of gain by by 3.9-7.1%.

EFFICIENCY OF BEEF PRODUCTION WITH THE INCLUSION OF WHOLE GRAIN CORN IN THE DIET

The article is devoted to the study of the effectiveness of the use of whole grain corn in feeding calves in order to determine the optimal norms for its inclusion in the diet. It was found that the inclusion of whole grain corn in the amount of 30 and 40% by weight of compound feed in the diet of young cattle at the age of 66-115 days had a positive effect on feed intake and intensity of animal growth, while reducing the feed costs and production prime costs. Thus, the daily live weight gain increased by 3.5% and 4.8% (774 and 784 g), while feed costs decreased by 1.1% and 1.8%, resulting in a 4.4% and 5.2% reduction in the prime cost of gain.

Effect of Replacing Corn Silage with Canola Silage on Feed Intake, Nutrient Digestibility, Milk Yield, and Thyroid Hormones of Lactating Dairy Cows

Introduction: Providing good quality forage in dairy cattle diet is vital for the dairy farm industry. Canola forage was newly added to dairy cows’ diet in Iran. The present study aimed to determine the effects of replacing corn silage with canola silage on feed intake, apparent digestibility, milk yield, milk composition, and thyroid hormone levels of dairy cattle in Mashhad, Iran. Materials and methods: Nine Holstein cows were used in this study and were allocated in a 3×3 change over Latin square design study. The trial consisted of 3 periods, each lasting for 20 days. The first 15 days were considered an adaptation period. Experimental diets were formulated to provide 33% of the total dry matter (DM) as forage. Canola silage was substituted with corn silage at levels of 0, 50, and 100% of DM. Results: Dietary concentrations of neutral detergent fiber (NDF) and acid detergent fiber increased when corn silage was replaced by canola silage. Replacing corn silage with canola silage caused a significant decrease in DMI. The apparent digestibility of DM and crude protein were not affected by the dietary replacement of corn silage with canola silage; however, organic matter and digestibility of NDF decreased significantly. When corn silage was replaced by canola silage, there were no significant changes in milk yield, fat-corrected milk, and milk composition in the investigated cattle, but milk protein changed significantly. The results indicated that 50% substitution of canola silage caused higher milk protein. Rumen fluid pH and its ammonia nitrogen concentration increased significantly in experimental animals. The concentrations of T3 and T4 decreased, whereas blood urea nitrogen concentration increased by dietary replacement of corn silage with canola silage. Conclusion: Canola silage can be substituted with corn silage, and feeding canola silage can be beneficial in some aspects.

156 Effect of Increasing Levels of Ergot Alkaloids in the Diet of Feedlot Cattle

Abstract This study evaluated the effects of feeding ergot alkaloids (EA) at increasing levels (0, 0.75, 1.5, and 3.0 ppm) to feedlot beef cattle over backgrounding (BG) and finishing (FS) phases on growth performance and carcass quality. Steers (n=240; 280±32 kg) were blocked by weight and randomly allocated to 16 pens (4 pens/treatment; 15 steers/pen). Treatments included: no added EA (CTL); or EA added at 0.75 (EA075); 1.50 (EA150); and 3.0 ppm (EA300). Steers were fed barley-based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d, then stepped up over 28 d to a 90% concentrate:10% silage (DM basis) FS diet for 119 d. Steers fed EA300 received CTL in FS after 77 days on feed (DOF). In the BG phase, a quadratic decrease (P=0.05) in ADG and a linear decrease in final BW (P=0.03) and total BW gain (P=0.02) were observed with increasing EA. In the FS phase, up to 77 DOF, there was a linear decrease in steers DMI (P=0.04), ADG (P=0.01), and total BW gain (P=0.01) with increasing levels of EA. Over the full FS phase (119 DOF), a quadratic response was observed for ADG (P=0.05), final BW (P=0.05), total BW gain (P=0.02) and carcass weight (P=0.05) with steers fed EA150 showing the lowest performance. Gain:feed was not affected (P&amp;gt;0.20) by EA in the BG or FS phase. Dressing percentage (P=0.02) showed a quadratic effect with EA300 being the lowest. Additionally, a linear increase in lean meat yield (P&amp;lt; 0.001) was observed with increasing EA. Including EA in the diet promoted a linear increase in rectal temperature (P&amp;lt; 0.01). In conclusion, increasing levels of EA in the diet reduced growth performance, but when EA was removed, steers showed compensatory weight gain.

PSII-B-13 Bacterial Composition of the Rumen Microbiome with a Bacillus Probiotic Added to the Diet of Feedlot Cattle

Abstract The threat of the development of an antibiotic resistant bacterium necessitates investigation for alternative feed additives. Probiotics are known to confer a health benefit to the animal and affect the production of the animal through increased nutrient digestibility. The aim of this study was to investigate the bacterial composition of the rumen of South African feedlot cattle when supplemented with a Bacillus probiotic. Twenty-four Bonsmara cattle were randomly divided into two groups: a basal diet (control, CTR) and the basal diet supplemented with Bacillus-based probiotic (B. licheniformis and B. subtilis; Bovacillus, Chr. Hansen A/S; BOV). The animals were fed for 120-days divided by starter, grower, and finisher diets. Four animals from each group were selected for rumen content collection via stomach tube during each phase. DNA extraction was performed and submitted for 16S rRNA sequencing (V3-V4). Approximately 41 300 ASVs were identified from 87 genera using DADA2, phyloseq and the RDP database. ANOSIM was used to determine different microbial profiles and Wilcoxon Rank Sum test to determine significant differences in the relative abundance of the microbes between the treatment groups. Microbial profiles in the starter (ANOSIM=0.0416) and grower (ANOSIM=0.1771) phases were similar between CTR and BOV. Most bacteria had greater abundance in CON compared with BOV in the starter phase. In the grower, BOV had a significantly greater abundance of Prevotella (p=0.028) and Lachnobacterium (p=0.042) compared to CTR. The microbial profiles between CTR and BOV differed in the finisher phase (ANOSIM=0.3229) with most of the bacteria having a significantly greater abundance in BOV compared with CTR including Roseburia (p=0.028), Fibrobacter (p=0.057) and Ruminococcus (p=0.028). These microbes as well as Prevotella are known fiber-degraders in the rumen microbiome. The results indicate a tendency in BOV for increased abundance of fibre-degrading microbes, however further studies are needed to validate these findings.

PSII-B-20 Altering the Particle Size of Supplemental Zeolite (Clinoptilolite) in Finishing Cattle Diets: Manure Characteristics and Ammonia Emissions

Abstract A potential strategy to limit ammonia (NH3) emissions from feedlots is the feeding of supplemental clinoptilolite (CLN), which has a high affinity for ammonium (NH4+). The particle size of CLN could influence its efficacy in binding NH4+ in the rumen and manure. Therefore, our objective was to determine the effects of feeding CLN (2% of diet DM) of two different particle sizes (30 and 40 µm) on manure N profile and NH3 emissions. Six beef heifers were used in a replicated 3 × 3 Latin square design with 21 d periods. Dietary treatments were: 1) finishing ration with no supplement (CON), 2) CON + 30-µm CLN (CL-30), and 3) CON + 40-µm CLN (CL-40). Grab fecal and spot urine samples were collected (d 19 to 21) for analysis. To determine NH3 emissions, six rectangular vented, non-steady state, closed chambers interfaced with a Fourier Transform Infrared Spectroscopy analyzer were used. Soil was added to chambers to a depth of 10 cm before addition of manure and incubated over a 7-d period. Data were analyzed using SAS. There was no diet effect (P ≥ 0.78) on urinary total nitrogen (N) and urea-N concentrations. However, urinary NH3-N concentration, which was less (P = 0.03) for CON than CL-40 heifers did not differ between CON and CL-30 heifers. Fecal N concentration, which tended to greater (P = 0.07) for CL-30 than CL-40 heifers did not differ between CON and CL-40 heifers. However, there was no diet effect (P = 0.25) on fecal NH3-N concentration. Ammonia emissions, which were less (P = 0.02) for manure from CL-40 than CL-30 heifers, did not differ between CON and CL-30 heifers during the first 48 h of incubation. In summary, feeding CL with different particle sizes resulted in changes in the manure N profile and NH3 emissions.

A Review of Probiotic Applications in Poultry: Improving Immunity and Having Beneficial Effects on Production and Health

Abstract A new class of feed additives and nutritional supplements, known as probiotics, include bacterial, fungal, and yeast cultures from various sources. Overall, probiotics are believed to promote the health and well-being of animals, birds, and humans in a variety of settings. Incorporating probiotics into the diets of cattle and poultry has been demonstrated to improve growth, feed conversion efficiency, immunological responses, and the animal's ability to manage enteric infections. The use of probiotic-enriched chicken feed has been shown to enhance egg production by as much as 30% among laying chickens. Probiotics may be used to fight off harmful microorganisms, create antibacterial compounds (such as bacteriocins or colicins), and alter the immunological response of the host, according to the National Institutes of Health. Pathogenic microbial strains such as Lactobacillus, Streptococcus, Bacillus, Enterococcus, Pediococcus, Aspergillus, and Saccharomyces are employed in the making of chicken products. The use of subtherapeutic doses of antimicrobial agents, including antibiotics, to combat or remove harmful bacteria and promote animal growth and feed efficiency has resulted in the accumulation of antibiotic residues in animal feed as well as the emergence of drug-resistant microbes in the feed supply chain. As a result of public health concerns, there has been a renewed emphasis on the use of probiotics in chicken production rather than antibiotics in recent years. This research examines the effects of probiotics and direct-fed microorganisms (DFM) on chicken health and performance, with a particular emphasis on the favourable effects they have on poultry health and performance.

A Review of Probiotic Applications in Poultry: Improving Immunity and Having Beneficial Effects on Production and Health

Abstract A new class of feed additives and nutritional supplements, known as probiotics, include bacterial, fungal, and yeast cultures from various sources. Overall, probiotics are believed to promote the health and well-being of animals, birds, and humans in a variety of settings. Incorporating probiotics into the diets of cattle and poultry has been demonstrated to improve growth, feed conversion efficiency, immunological responses, and the animal's ability to manage enteric infections. The use of probiotic-enriched chicken feed has been shown to enhance egg production by as much as 30% among laying chickens. Probiotics may be used to fight off harmful microorganisms, create antibacterial compounds (such as bacteriocins or colicins), and alter the immunological response of the host, according to the National Institutes of Health. Pathogenic microbial strains such as Lactobacillus, Streptococcus, Bacillus, Enterococcus, Pediococcus, Aspergillus, and Saccharomyces are employed in the making of chicken products. The use of subtherapeutic doses of antimicrobial agents, including antibiotics, to combat or remove harmful bacteria and promote animal growth and feed efficiency has resulted in the accumulation of antibiotic residues in animal feed as well as the emergence of drug-resistant microbes in the feed supply chain. As a result of public health concerns, there has been a renewed emphasis on the use of probiotics in chicken production rather than antibiotics in recent years. This research examines the effects of probiotics and direct-fed microorganisms (DFM) on chicken health and performance, with a particular emphasis on the favourable effects they have on poultry health and performance.

Detoxified castor-bean meal replaces soybean meal in the diet of pasture-finished steers

The use of agroindustrial byproducts in cattle diets, such as castor-bean (Ricinus communis L.) meal, is a more sustainable practice because it does not compete with human food and reduces the volume of organic waste deposited in the environment. The aim of this study was to examine the effect of replacing soybean (Glycine max (L.) Merr.) meal with castor-bean meal on the intake, digestibility, feeding behavior and performance of crossbred steers supplemented while on Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster ‘Marandu’ pasture. The experiment was laid out in a randomized complete design with 40 animals, which started the experiment weighing 227.1 kg, at 10 mo of age, and were divided into four treatment groups. Castor-bean meal was added to replace soybean meal at the levels of 0, 90, 180, and 280 g kg-1 in the supplement, which was supplied at the rate of 0.4% of body weight. Total DM, pasture DM and neutral detergent fiber intakes did not change (P > 0.05) with the castor-bean levels added to the supplement. Ether extract intake and digestibility decreased linearly (P < 0.05). The animals showed no differences (P > 0.05) in production performance (average daily gain), which averaged 0.65 kg d-1. Grazing, idle, and rumination times were not influenced (P > 0.05) by the treatments. Castor-bean meal can be included up to 280 g kg-1 in the total diet without changing the performance of crossbred steers finished on tropical pasture.

Effect of Duration of High-Grain Feeding on Chewing, Feeding Behavior, and Salivary Composition in Cows with or without a Phytogenic Feed Supplement

Simple SummaryThis study evaluated the effects of the duration of high-grain feeding and a phytogenic feed supplement on the chewing, eating, and lying behavior as well as the salivation dynamics in dairy cows. A control group of cows with no supplementation was compared to a group receiving a phytogenic feed supplement. An increased duration of the high-grain diet increased meal size, but reduced rumination, the total chewing time, and the chewing index. Similarly, as the experiment progressed, the cows sorted against short feed particles. The results also showed that the duration on the high-grain diet increased the salivary pH; however, the salivary phosphate decreased at the start of high-grain feeding. Feed ensalivation also decreased after 4 weeks of consuming the high-grain diet. The supplemented cows sorted in favor of fiber-rich feed particles in week two and had greater salivary pH in week four on the high-grain diet. Our study showed that the duration of feeding exacerbates the negative impacts of high-grain diets in cows. However, supplementation with the feed additive mitigated some of these negative effects.Switching diets from forage to a high-grain (HG) diet increases the risk of rumen fermentation disorders in cattle. However, the effects of the duration of the HG feeding, after the diet switch, on animal behavior and health have received considerably less attention. This experiment primarily aimed to assess the effects of the duration of an HG diet on the chewing, eating, and lying behavior and salivation dynamics in a control group (CON) and a group of cows receiving a phytogenic feed supplement (TRT) at 0.04% (DM basis), which included L-menthol, thymol, eugenol, mint oil, and cloves powder. The experiment was a crossover design with nine non-lactating cows, and two experimental periods with an intermediate washout of four weeks. In each period, the cows were first fed a forage diet for a week to collect baseline measurements representing week 0; then, the diet was switched over a week to HG (65% concentrate), which was fed for four continuous weeks (week 1, week 2, week 3, and week 4 on an HG diet, respectively). The cows were divided in two groups of four and five animals and were randomly allocated to CON or TRT. The data analysis revealed that at the start of the HG feeding, the dry matter intake and the cows’ number of lying bouts increased, but the eating time, rumination time, and meal frequency decreased, resulting in a greater eating rate. We also found that an advanced duration on an HG diet further decreased the rumination time, total chewing time, chewing index, and sorting in favor of short feed particles, with the lowest values in week 4. The feed bolus size increased but feed the ensalivation decreased in week 4 compared to week 0. The dietary switch increased salivary lysozyme activity, and the advanced duration on the HG diet increased salivary pH, but salivary phosphate decreased in weeks 1 and 2 on the HG diet. Supplementation with TRT increased sorting in favor of physically effective NDF (peNDF) in week 2 and increased salivary pH in week 4 on an HG diet. Overall, the negative effects of the HG diet in cattle are more pronounced during the initial stage of the HG feeding. However, several detrimental effects were exacerbated with the cows’ advanced duration on feed, with host adaptive changes still observed after 3 and 4 weeks following the diet switch. The TRT mitigated some of the negative effects through the temporal improvement of the salivary properties and the intake of peNDF, which are known to modulate rumen fermentation.

Ruminal alkalizing potential of brucite and sodium bicarbonate in feedlot cattle diets

The effects of brucite (BR; magnesium hydroxide) and sodium bicarbonate (SB) on ruminal fermentation characteristics were evaluated following a ruminal glucose challenge. Four Holstein steers were used in a 4 × 4 Latin square design with 4 dietary treatments: (1) control (CTL; no buffer), (2) 0.5% BR, (3) 1% BR, or (4) 1% SB. The basal diet contained 70% steam-flaked wheat. On the collection day, 500 g of glucose was introduced through a ruminal cannula 1 h after the morning feeding. Time required for 50% reactivity at pH 6.0 of BR and SB was 450 and 0.5 min, respectively. Ruminal pH tended to decrease (P < 0.09) 1 h after feeding (just before the glucose challenge), but ruminal fluid buffer capacity was greater (P = 0.01) 1 h before feeding for CTL than buffer-supplemented diets. Average pH was not influenced by buffer supplementation. Buffers tended (P = 0.07) to reduce average ruminal buffer capacity. Ruminal pH and lactate had an inverse relationship (r = −0.59). Average ruminal VFA concentration tended to be lower (P = 0.06) for SB than BR. Compared with CTL, buffers decreased (P = 0.03) ruminal protozoa. Supplemental BR had lower (P < 0.05) average ruminal glucose concentration than SB. Buffer supplementation decreased average ruminal osmolality (P = 0.02). Ruminal alkalizing equivalence of BR and SB were similar. Neither appreciably altered ruminal buffering capacity. Although, both reduced ruminal lactate during the first few hours following a glucose challenge. Buffer supplementation may depress ruminal protozoa.