Total Mixed Ration Research Articles

The impact of various protein concentrations in total mixed ration on rumen fermentation and haematobiochemical indicators in Vechur cattle

The impact of various protein concentrations in total mixed ration on rumen fermentation and haematobiochemical indicators in Vechur cattle

The Effect of Supplementation of Oak Tannin Extract on Digestibility, Metabolisable Energy, Methane Production and Ammonia Production in Lamb Diets

The aim of current experiment was to determine the effect of supplementation of oak tannin extract on gas production, methane production, digestibility, metabolisable energy and ammonia production of lamb diets using in vitro gas production technique. Oak tannin extract was included into total mixed ration at the 0, 2, 4 and 6 % on a dry matter basis. Although supplementation of oak tannin had no significant effect on gas, methane whereas supplementation had a significant effect on ammonia production of lamb diets. Gas and methane production of total mixed rations ranged from 50.25 to 53.25 ml and 7.72 to 8.15 ml respectively. Ammonia concentration of mixed rations ranged from 54.97 to 62.67 mg/100 ml. The decrease in ammonia of lamb diets per g oak supplementation was 0.1263 mg /100 ml. Metabolisable energy and organic matter digestibility of lamb diets ranged from 10.42 to 10.80 MJ kg DM and 70.27 to 73.02 % respectively. This study clearly showed that oak tannin had an anti-proteolytic potential for ruminant animals and supplementation of oak tannin significantly reduced ammonia production without compromising digestibility of diets. Therefore, oak tannin can be used to manipulate the rate and extent of degradation of protein in the rumen. However, before large implication, oak tannin should be further investigated using in vivo experiment to determine the toxic level of oak tannin in ruminant animals.

Effect of Calcareous Marine Algae Buffer on High-Producing Dairy Cows during Peak Lactation.

The aim of the study was to investigate the effect of calcareous marine algae (Lithotamium calcareum)-based rumen content buffer (CMA) included in concentrated feed within total mixed ration (TMR), fed to 34 peak lactation (87-144 days in milk) Holstein dairy cows, randomized into two groups (group A, n = 17; group B, n = 17), wearing collars with accelerometers, and housed a in barn with automatic feed-weigh troughs. During the first phase P1, group A received TMR with CMA (TMR-E) and group B was fed TMR without the buffer (TMR-C). For P2, the treatments in the groups were exchanged. Feed intake, feeding time (FT), rumination time (RT), milk yield, milk composition, and rumen pH were measured by barn technologies, and rumen fluid and feces composition were analyzed in the laboratory. Differences between the TMR-E and TMR-C in most parameters under study were statistically insignificant, except overall FT and RT, which differed significantly between the groups. Group A, feeding at P1 by TMR-E, exhibited higher FT and RT than Group B (202 min/cow/day vs. 184 min/cow/day, and 486 min/cow/day vs. 428 min/cow/day, respectively). The RT significantly increased after switching from TMR-C to TMR-E. This implies that the buffer effect is delayed and persists after the withdrawal. In the group of cows that received control TMR without buffer in the first phase, RT and milk protein content increased significantly in the first week after the addition of buffer.

Can a gradual weaning and separation process reduce weaning distress in dam-reared dairy calves? A comparison with the 2-step method

The weaning and separation phase remains one of the biggest challenges for cow-calf-contact systems, but a gradual process that better mimics the naturally occurring reduction in milk intake has not yet been scientifically investigated. Therefore, the aim of our study was to compare behavioral and physiological indicators of distress in 3 mo-old dam-reared dairy calves (with previous full-time cow-calf contact) weaned and separated either via gradual reduction of contact time with the dam (GR, 1 week half day contact, 1 week morning contact, 1 week fence-line contact before complete separation, n = 18) or via 2-step weaning using a nose flap (NF, 2 weeks access to dam with a nose flap, 1 week fence-line contact before complete separation, n = 18). Behavior was recorded 1 week before (or for lying 3 weeks before) weaning start and during the 3 week weaning and separation period with direct observations on 4 d per week or via accelerometers (locomotor play, lying behavior). Blood and fecal samples were taken twice per week from weaning start until 3 weeks after weaning start. Calves were weighed weekly. Statistical analysis was conducted using (generalized) linear mixed models. Over the whole weaning and separation phase, NF calves showed a stronger decrease in the number of lying bouts, amount of locomotor play and average daily weight gains, as well as a higher increase in total mixed ration feeding time compared with GR calves, whereas GR calves vocalized more often and showed more searching behavior than NF calves. Also, the neutrophil:lymphocyte ratio of NF calves was elevated on d 3 after insertion of the nose flaps compared with baseline, but showed no change for GR calves on any sampling day. Overall, results point toward a favorable effect of a gradual weaning strategy on reduction of weaning and separation distress in dam-reared dairy calves, but the method requires further improvement from the protocol used in our study.

Effects of Nutritional Factors on Fat Content, Fatty Acid Composition, and Sensorial Properties of Meat and Milk from Domesticated Ruminants: An Overview.

The meat and milk products from domesticated ruminants are important foods within a balanced diet, offering a rich source of energy, protein, fats, minerals, and vitamins. The sensorial properties of meat and milk are mainly linked to their fat content and fatty acid composition, which are influenced by the feeding background or nutrient composition of diets. While several studies have investigated the nutritional effects on the fat content and fatty acid profile of ruminant meat and milk, as well as their relationship with sensorial properties, a comprehensive overview of these effects is lacking. This paper summarises current literature and discusses changes to fatty acid composition (including ω-3 concentrations), fattiness, and associated quality traits of sheep, goat, beef cattle, alpaca, and llama meat that can be achieved by using different forages or feeds in a total mixed ration. Additionally, it presents the shelf life and nutritional value of meat, milk, and cheeses from the milk of dairy cattle, buffalo, goats, and sheep as influenced by a ruminant diet. Further advancement in these areas will promote the sustainability of ruminant production and its associated feeding systems in achieving premium quality animal-derived foods.

The effect of supplementary selenium source on apparent and true absorption, retention, performance, and selenium status in lactating Holstein cows

Selenium is an essential trace mineral for dairy cattle and can be provided in the diet in various forms that may differ in bioavailability. The objective of this study was to determine how source of Se affects animal performance, Se status, retention, and apparent and true absorption. Multiparous Holstein cows (n = 24; 597 ± 49 kg body weight) were blocked by days in milk (DIM; 161 ± 18) and randomly assigned to receive 0.3 mg Se/kg of dry matter (100% of NASEM requirements) of either organic Se (ORG; selenized yeast) or inorganic Se (INO; sodium selenite). The Se premix was top-dressed on a common total mixed ration fed daily and mixed into the top 15 cm directly before feeding. Following an 11-wk adaptation period, cows received simultaneous infusions of an intraruminal isotope dose of 77Se in the same chemical form as the premix, and an intravenous dose of 82Se in an inorganic form. Infusions were followed by a 4-d period of blood and rumen fluid sampling, and total collection of feces, urine, and milk. Daily dry matter intake (23 ± 0.6 kg), milk yield (35 ± 1.2 kg), and serum Se (0.11 ± 0.003 µg/g) were not different between treatments during the adaptation period, but milk Se concentrations were greater for ORG compared with INO. Serum 77Se maximum concentration (Cmax) and area under the curve (AUC) were not different between treatments for 72 h following infusion, but rumen fluid 77Se AUC was higher for ORG than INO. Apparent absorption (64 ± 1.4%), and retention (44 ± 1.5%) of the 77Se dose did not differ between treatments. True absorption was calculated using 82Se enrichment in serum and feces and was determined to be 69 ± 1.3% and did not differ between treatments. Fecal excretion of the 77Se dose was not different between treatments (36 ± 1.4%), but ORG had lower urinary excretion and higher milk excretion compared with INO. These results indicate that organic Se resulted in greater Se concentration of milk and lower urinary Se excretion into the environment, but absorption, Se status, and performance of the cow were not affected by Se source at this supplementation level.

Enhancing Milk Quality and Antioxidant Status in Lactating Dairy Goats through the Dietary Incorporation of Purple Napier Grass Silage.

Oxidative stress resulting from an imbalance between oxidants and antioxidants can cause damage to certain cellular components. Purple Napier grass, a semi-dwarf variety, is characterized by its purple leaves and contains anthocyanins, which provide it with antioxidant properties. This study examined the effects of feeding purple Napier grass ("Prince") silage to lactating dairy goats on blood antioxidant activity, milk yield, and milk quality. Eighteen female Saanen crossbred goats, weighing 52.34 ± 2.86 kg and producing milk for 14 ± 2 days, were systematically divided into three groups based on their lactation period in the previous cycle as follows: early, mid, and late lactation. In a randomized complete block design (RCBD), treatments were randomly allocated to six animals in each block. The dairy goats were fed a total mixed ration (TMR) consisting of the three following treatments: control (100% Napier Pakchong 1 grass silage), 50% (a 50% replacement of the control with purple Napier grass silage), and 100% (100% purple Napier grass silage). The results show that goats who were fed a diet including 100% purple Napier grass silage showed higher levels of certain milk contents, especially with regard to lactose, when compared to those who were fed a control diet, as well as a diet with a 50% replacement of purple Napier grass silage. The somatic cell count (SCC) of these goats was reduced. In terms of antioxidant activity, dairy goats who were fed 100% purple Napier grass silage showed higher levels of enzymes in both plasma and milk, including glutathione s-transferase, total antioxidant capacity, superoxide dismutase, and 2,2-diphenyl-1-picrylhydrazyl radical, compared to the control group and the 50% replacement group. The plasma and milk of these goats showed lower levels of malondialdehyde. The dairy goats who were fed a 100% purple Napier grass silage diet showed higher concentrations of anthocyanins, including C3G, P3G, Peo3G, M3G, Cya, Pel, and total anthocyanins in milk, when compared to the control group and the 50% replacement group. The increased replacement of purple Napier grass silage led to significant differences in lactose levels, somatic cell count, glutathione S-transferase, total antioxidant capacity, superoxide dismutase, 2,2-diphenyl-1-picrylhydrazyl radical, and the composition of anthocyanins. This study provides evidence to support the use of purple Napier grass silage as a beneficial source of roughage for lactating dairy goats.

Conch Shell (Turbinella pyrum) Powder: A Potential Marine Biological Source of Calcium and Some Trace Minerals for Growing Crossbred Calves.

The present study was conducted to evaluate the effect of feeding conch shell (Turbinella pyrum) powder (either fresh or calcined) as a marine organic source of calcium (Ca) supplemented in the diet of crossbred calves on voluntary intake, growth performance, and blood biochemistry in growing crossbred Jersey calves. A growth trial of 90days was conducted on 15 Jersey crossbred female calves (Av. weight, 70.68 ± 2.90kg; Av. age, 197.73 ± 12.40days), equally divided into three groups of 5 animals each, i.e., control (T0), treatment 1 (T1), and treatment 2 (T2). All animals were fed total mixed ration (TMR) prepared with a concentrate mixture, chaffed paddy straw, and green fodder at the ratio of 40:30:30 on DM basis. Calves under the control group were fed with TMR containing a standard mineral mixture having dicalcium phosphate (DCP) as a Ca source. Calves under T1 group were supplemented with TMR containing fresh conch shell powder (FCSP), and T2 calves were fed with TMR containing conch shell calcined powder (CSCP) as Ca source. We observed 11.66% increase (p < 0.01) in Ca concentration in CSCP compared to FCSP. The concentration of minerals like Mg, Co, Mn, and Fe was enhanced in CSCP compared to the FCSP. However, the calcination process of fresh conch shell powder (FCSP) reduced the concentration of Cu, and Zn. The Ca/P ratio was estimated as 2.11, 2.06, and 2.10 in T0, T1, and T2 diets, which could be considered ideal for calf ration. Calves under T1, and T2 groups consumed significantly (p < 0.001) greater amounts (g/kg W0.75) of DM and CP compared to T0. However, increased voluntary intake did not translate into increased body weight gain (kg), and feed conversion ratio (kg DMI/kg gain) in T1 and T2 groups in comparison to T0. We observed similar blood glucose, urea, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine transaminase (ALT) concentration among the three treatments. Ca, and P levels in blood plasma were also identical among the three groups. The digestibility of Ca was increased significantly (p = 0.01) in FCSP (T1)- and CSCP (T2)-treated calves compared to control (T0) calves. Similarly, T1 and T2 enhanced P digestibility compared to T0. This first report with short-term experimentation depicted some promising scope for the use of locally available conch shell powder (fresh or calcined form) as a potential source of Ca for feeding to livestock, because these new sources of Ca did not affect intake, digestibility of Ca and P, growth performance, blood chemistry, and liver enzymes negatively in weaned crossbred calves.

Characterization of rumen microbiome and immune genes expression of crossbred beef steers with divergent residual feed intake phenotypes

We investigated whole blood and hepatic mRNA expressions of immune genes and rumen microbiome of crossbred beef steers with divergent residual feed intake phenotype to identify relevant biological processes underpinning feed efficiency in beef cattle. Low-RFI beef steers (n = 20; RFI = − 1.83 kg/d) and high-RFI beef steers (n = 20; RFI = + 2.12 kg/d) were identified from a group of 108 growing crossbred beef steers (average BW = 282 ± 30.4 kg) fed a high-forage total mixed ration after a 70-d performance testing period. At the end of the 70-d testing period, liver biopsies and blood samples were collected for total RNA extraction and cDNA synthesis. Rumen fluid samples were also collected for analysis of the rumen microbial community. The mRNA expression of 84 genes related to innate and adaptive immunity was analyzed using pathway-focused PCR-based arrays. Differentially expressed genes were determined using P-value ≤ 0.05 and fold change (FC) ≥ 1.5 (in whole blood) or ≥ 2.0 (in the liver). Gene ontology analysis of the differentially expressed genes revealed that pathways related to pattern recognition receptor activity, positive regulation of phagocytosis, positive regulation of vitamin metabolic process, vascular endothelial growth factor production, positive regulation of epithelial tube formation and T-helper cell differentiation were significantly enriched (FDR < 0.05) in low-RFI steers. In the rumen, the relative abundance of PeH15, Arthrobacter, Moryella, Weissella, and Muribaculaceae was enriched in low-RFI steers, while Methanobrevibacter, Bacteroidales_BS11_gut_group, Bacteroides and Clostridium_sensu_stricto_1 were reduced. In conclusion, our study found that low-RFI beef steers exhibit increased mRNA expression of genes related to immune cell functions in whole blood and liver tissues, specifically those involved in pathogen recognition and phagocytosis regulation. Additionally, these low-RFI steers showed differences in the relative abundance of some microbial taxa which may partially account for their improved feed efficiency compared to high-RFI steers.

Total Replacement of Soybean Meal with Sundried Soymilk Residue in the Total Mixed Ration has a Negative Impact on Intake, Digestibility, and Milk Production in Dairy Goats.

This study aimed to evaluate whether total replacement of soybean meal (SBM) with sundried soymilk residue (SSR) in a total mixed ration (TMR) affects intake, digestibility, milk production, and blood metabolites in dairy goats. A total of 12 healthy Saanen dairy goats (40.12 ± 5.80 kg of BW) in midlactation (31.23 ± 10.12 days) were used in a randomized complete design (n = 4 goats/group). Dietary treatments were based on a TMR as follows: control TMR without SSR (CON) or SBM-based TMR with 50% or 100% of SSR replacing SBM (SSR-50 and SSR-100, respectively). All goats had ad libitum access to feed and clean water throughout the experiment. The dry matter (DM) intake decreased (p < 0.05) with the increasing replacement ratio of SBM and was lowest in the SSR-100 group. Similarly, organic matter (OM) digestibility was lowest (p < 0.05) in the SSR-100 group. However, the digestibility of DM, CP, NDF, and ADF did not change (p > 0.05) by dietary treatments. Compared with CON, the milk yield decreased significantly (p < 0.05) with increasing replacement ratio of SBM. In contrast, milk composition such as total solids, solids-not-fat, milk fat, lactose, protein, and pH were not influenced (p > 0.05) by feeding dietary SSR. Compared with other treatments, blood glucose concentration was lower (p < 0.05) in the SSR-100 group. In contrast, packed cell volume, glucose, and plasma urea nitrogen concentrations did not differ (p > 0.05). The results indicated that SSR could replace SBM in a TMR at less than 50%. Thus, the present study provides support for further investigation to enhance the utilization of soybean waste as an alternative protein source in the TMR for dairy goats and potentially other ruminants.

Milk consumption and behavior of calves in automated calf feeders as early indicators of weaning liveweight

Modern intensive dairy farming relies on data to aid and prioritize management decisions made on farm. Decisions made early in an animal's life can have lasting effects on welfare, productivity, longevity, and profitability. Precision technology such as automated calf feeders (ACF) allow the customization of feeding programs, but despite this, weaning weights (WWT) vary substantially between calves. This observational study used a 3-yr dataset comprising 1,440 female Holstein Friesian calves at a single intensive commercial dairy farm (Dairy Australia feeding system 5; indoor, total mixed ration) using ACF to (1) determine the variability in WWT (as a proxy of animal performance) of calves within this system; (2) identify the contributing factors responsible for the variation in WWT; and (3) identify potential early management intervention points that could be indicative of the performance of calves at weaning within the system. Calves entered the ACF at 10 d of age with 12 calves per ACF; calves were weighed at birth and weaning using weigh scales. We discovered a large range of calf WWT (41–118 kg/head) at ~60 d of age despite the application of strict uniform management protocols. Our results from modeling showed that WWT was significantly and positively associated with birth weight (BWT), with low BWT calves (<36 kg) achieving an average of 70 kg weight at weaning. In contrast, heavier BWT (>36 kg) calves achieved an average of 82 kg at weaning. Based on calf feeder data, cumulative milk consumption and cumulative unrewarded visits to the feeder, as well as BWT, were identified as indicators of greater WWT as all these were highly significant terms in the model for WWT. Results suggest that quantifying consumption and number of visitations to the ACF at d 5 may allow farmers to identify, with time to intervene, calves underperforming within the feeder or system, therefore increasing their potential for growth. Additionally, this demonstrated that greater milk consumption (>30 kg) and interaction with the feeder up to d 5 in the feeder is more likely to yield a WWT >75 kg, identifying a potential point for management intervention for calves below consumption and interaction thresholds (e.g., by developing alarm systems based on consumption or visitation number).

88 Impacts of trace mineral source and ancillary drench on steer performance during a 60-day backgrounding phase

Abstract This experiment evaluated the impacts of supplementing organic complexed Cu, Co, Mn, and Zn on productive and health responses of high-risk beef cattle during a 60-d backgrounding phase. Crossbred steers (n = 120) were purchased at auction and transported to the experimental facility. Steer BW was recorded at arrival (d -1; initial shrunk BW = 227.7 ± 1.3 kg). On d 0, steers were ranked by BW and allocated to 1 of 8 groups (8 steers/group) and housed in drylot pens (6 m x 12 m) equipped with GrowSafe automated feeding systems (Model 8000; 2 bunks/pen; d 0 to 60). Groups were randomly assigned to receive a total mixed ration (TMR; 47% corn) containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 40); 2) organic complexed sources of Cu, Mn, Co, and Zn (AAC; Zinpro Availa 4; Zinpro Corp., Eden Prairie, MN; n = 40); or 3) AAC and an organic complexed trace mineral drench (APF; 30 mL/hd; Zinpro ProFusion, Zinpro Corp.) on d 0 and ancillary to morbidity treatment (n = 40). Diets provided the same daily amount of energy, protein, macro minerals and trace minerals based on 7 g/steer daily of Zinpro Availa 4. Steers were assessed for bovine respiratory disease (BRD) signs daily. Liver biopsies were performed on day 0, 28 and 60. Final BW was recorded on d 60 and 61. Blood samples were collected on d 0, 2, 6, 10, 13, 21, 28 and 45. No treatment differences were detected (P ≥ 0.23) for TMR intake, final BW, ADG, feed efficiency, or BRD incidence. Mean liver Co concentrations were greater (P = 0.02) in AAC and APF compared with INR steers. Mean liver Cu was greater (P = 0.02) in APF compared with AAC steers. Liver Zn tended to be greater (P = 0.10) on d 28 but less (P = 0.05) on d 60 for INR compared with AAC and APF steers. Plasma cortisol was least (P = 0.05) for steers supplemented with AAC on d 6, whereas AAC steers tended to have greater (P = 0.09) plasma cortisol on d 13 compared with APF. Plasma haptoglobin tended to be greater (P ≤ 0.10) for INR steers on d 28 and 45 compared with AAC and APF. While supplementing cattle with AAC or INR results in similar animal performance and clinical disease, AAC and APF reduces stress and acute phase protein responses.

Meta-analysis of the relationship between dietary starch intake and enteric methane emissions in cattle from in vivo experiments.

Different sources and levels of starch in the total mixed ration might result in different rumen fermentation profiles, rumen microbial composition, and enteric methane production. The current study aimed to evaluate the effect of dietary starch intake on enteric methane production through a meta-analytical approach by integrating related published studies. Papers that provided study results on enteric methane production from cattle fed different sources and levels of starch were selected. A total of 52 publications were filtered based on some specified criteria, comprised of 73 studies focused on enteric methane production in cattle fed a basal diet supplemented with starch. The collected data were subjected to statistical meta-analysis through a mixed methodology model. The p-value and root mean square error (RMSE) were applied as the statistical models. Results showed that increasing the level of dietary starch intake and its digestibility in the rumen as well as increasing propionate significantly decreased the acetate to propionate (A/P) ratio as well as enteric methane production (p < 0.01). It is concluded that the addition of starch to diets mitigates enteric methane production from cattle, primarily through two ways, i.e., manipulation of the protozoa population and alteration to a lower A/P ratio.

Effect of Direct Fed Microbial (DFM) on in-vitro Methanogenesis and Dry Matter Digestibility

The in-vitro rumen fermentation study was conducted to evaluate the effect of supplementation of direct-fed microbial (DFM) in the total mixed ration (TMR) on total gas production, methanogenesis and dry matter digestibility by using rumen liquor of adult Surti buffaloes. DFM was supplemented at 0, 1, 2, 3, 4, 5, 6, 7, and 8% with TMR (65% Straw and 35% concentrate) for in-vitro gas production trials. The result of the in-vitro study revealed significantly (P&lt;0.05) higher IVDMD (57.03%) and lower CH4 production (3.20 ml CH4/100 mg DDM) at a 3% level of DFM supplementation in TMR. Based on the overall results of in-vitro studies 3% level of DFM supplementation was found to be most suitable for further in-vivo studies in adult Surti buffaloes.

Duration of Zearalenone Exposure Has Implications on Health Parameters of Lactating Cows.

There is a limited research focus on evaluating the detrimental effects of prolonged zearalenone (ZEN) intake on dairy cows' health under controlled conditions. This experiment was conducted to evaluate whether the length of exposure to a ZEN-contaminated total mixed ration (TMR) at a level of 9.45 mg per day can negatively influence animal health parameters, such as milk composition, rumen and fecal fermentation, and the chewing activity of lactating dairy cows. For this experiment, we used 18 lactating Simmental cows that were fed a diet of 60% forage and 40% concentrate (on dry matter basis) for 26 consecutive days. The first 4 days were for adaptation prior to the first sampling day (day 0). The sampling events took place on day 0 (baseline) without ZEN, followed by day 1, day 7, day 14, and day 21 (with toxin). Dry matter intake (DMI) and ruminating chews per minute increased on the third week of ZEN inclusion; meanwhile, ruminating, eating, and drinking times were not affected. Most milk composition variables were also unaffected. Rumen fluid osmolality increased on day 21 and total short-chain fatty acids (SCFA) of ruminal fluid decreased on day 7. Fecal SCFA increased on day 21 and the acetate-to-propionate ratio increased from day 1 onwards, showing the influence of toxin intake. Animal health parameters, like heart rate, respiratory rate, and body temperature, were negatively influenced by ZEN intake, all increasing consistently on days 4 and 6, 9 and 12, and 16 and 18, respectively. The liver enzyme glutamate dehydrogenase decreased in response to ZEN intake on day 7. A total daily ZEN intake at the level of 9.45 mg did not show detrimental effects on DMI. Nevertheless, certain health parameters were negatively affected, including body temperature, respiratory rate, and heart rate, starting from the 7th day of ZEN intake, with additional signs of possible loss of water balance on the last sampling day.

Evaluation of Partial Replacement of Barley Grain with Heated Potato Processing By-products in the Diet of Dairy Cows Using an In vitro Gas Production Technique

Background: The increasing urban population requires more dairy product (meat and milk) production; therefore, using agricultural sector by-products as animal feedstuffs has found double importance.&#x0D; Objective: The effects of replacing barley grain with heated potato slices (HPS) and French fries waste (FFW) in iso-energetic total mixed dairy cow rations on cumulative gas production and in vitro DM degradability were evaluated using in vitro techniques.&#x0D; Methods: Seven experimental dairy cow total mixed rations (TMR) were formulated based on partial replacing barley grain with HPS or FFW, including Control: a diet containing 16% (DM basis) barley grain as one of the main sources of non-forage carbohydrates; 5 HPS: a diet containing 11% barley grain and 5% HPS; 10 HPS: a diet containing 6% barley grain and 10% HPS; 15 HPS: a diet containing 1% barley grain and 15% HPS; 5 FFW: a diet containing 11% barley grain and 5% FFW; 10 FFW: a diet containing 6% barley grain and 10% FFW; 15 FFW: a diet containing 1% barley grain and 15% FFW. Two in vitro gas production approaches were conducted separately to measure the production of gas volumes and dry matter (DM) degradability at 2, 4, 6, 12, 24, 36, and 48 hours of incubation.&#x0D; Results: After 48 h of incubation, the gas production volume varied between 174 and 197 ml/g DM, with the highest value observed with control and the lowest value with FFW treatments (P &lt; 0.05). Also, the gas production rate for the insoluble fraction varied from 0.031 to 0.054 ml/h and was higher for HPS treatments than for control and FFW treatments (P &lt; 0.05). After 48 h of incubation, DM degradability was significantly lower for the control than other treatments. DM effective degradability, with a passage rate of 0.05 h−1, found to be higher for FFW and HPS treatments compared with the control. Moreover, the rate of the B fraction degradation was significantly lower for the control (0.14 % h−1) than for treatments.&#x0D; Conclusion: The heated potato processing by-products could be replaced with barley grain by 15% in the diet of dairy cows without having negative effects on ruminal fermentation.

Long-term effects of 3-nitrooxypropanol on methane emission and milk production characteristics in Holstein-Friesian dairy cows

The objective was to determine the long-term effect of 3-nitrooxypropanol (3-NOP) on CH4 emission and milk production characteristics from dairy cows receiving 3-NOP in their diet for a full year, covering all lactation stages of the dairy cows. Sixty-four late-lactation Holstein-Friesian cows (34% primiparous) were blocked in pairs, based on expected calving date, parity, and daily milk yield. The experiment started with an adaptation period of 1 wk followed by a covariate period of 3 wk in which all cows received the same basal diet and baseline measurements were performed. Directly after, cows within a block were randomly allocated to 1 of 2 dietary treatments: a diet containing on average 69.8 mg 3-NOP/kg DM (total ration level, corrected for intake of nonsupplemented GreenFeed bait) and a diet containing a placebo. Forage composition as well as forage-to-concentrate ratio altered with lactation stage (i.e., dry period and early, mid, and late lactation). Diets were provided as a total mixed ration, and additional bait was fed in GreenFeed units (C-Lock Inc.), which were used for emission measurements. Supplementation of 3-NOP did not affect total DMI, BW, or BCS, but resulted in a 6.5% increase in the yields of energy-corrected milk and fat- and protein-corrected milk (FPCM). Furthermore, milk fat and protein as well as feed efficiency were increased upon 3-NOP supplementation. Overall, a reduction of 21%, 20%, and 27% was achieved for CH4 production (g/d), yield (g/kg DMI), and intensity (g/kg FPCM), respectively, upon 3-NOP supplementation. The CH4 mitigation potential of 3-NOP was affected by the lactation stage dependent diet to which 3-NOP was supplemented. On average, a 16%, 20%, 16%, and 26% reduction in CH4 yield (g/kg DMI) was achieved upon 3-NOP supplementation for the dry period, and early, mid, and late-lactation diets, respectively. The CH4 mitigation potential of 3-NOP was affected by the length of 3-NOP supplementation within a lactation stage dependent diet and by variation in diet composition within a lactation stage dependent diet as a result of changes in grass and corn silage silos. In conclusion, 3-NOP reduced CH4 emission from cows receiving 3-NOP for a year, with a positive effect on production characteristics. The CH4 mitigation potential of 3-NOP was influenced by diet type, diet composition, and nutrition value, and the efficacy of 3-NOP appeared to decline over time but not continuously. Associated with changes in diet composition, increased efficacy of 3-NOP was observed at the start of the trial, at the start of a new lactation, and, importantly, at the end of the trial. These results suggest that diet composition has a large effect on the efficacy of 3-NOP, perhaps even larger than the week of supplementation after first introduction of 3-NOP. More studies are needed to clarify the long-term effects of 3-NOP on CH4 emission and to further investigate what influence variation in diet composition may have on the mitigation potential of 3-NOP.

Synergistic Effects of Essential Oil Blends and Fumaric Acid on Ruminal Fermentation, Volatile Fatty Acid Production and Greenhouse Gas Emissions Using the Rumen Simulation Technique (RUSITEC)

This study investigated the combined impact of essential oil blends (EOBs) and fumaric acid (FA) on ruminal fermentation in dairy cows using the rumen simulation technique (RUSITEC) system. Three rumen-cannulated, non-lactating Holstein Friesian cows served as inoculum donors. The substrate, a total mixed ration (TMR), comprised corn silage, alfalfa hay, and a concentrate mix in a 3:1:1 ratio. The four treatments evaluated were Control (TMR without additives), EFA1 (TMR + EOB1 + FA), EFA2 (TMR + EOB2 + FA), and EFA3 (TMR + EOB3 + FA). Sixteen fermentation chambers were randomly assigned to the treatments, each with four replicates, following a completely randomized design during a 9-day experimental period. EOBs and FA were added at 10 µL/g feed and 3% of TMR, respectively. After a 4-day adaptation, samples were collected for 5 days. Results revealed that EFA1 significantly reduced (p = 0.0351) CH4 emissions by 60.2% without negatively impacting dry matter disappearance, fiber fraction digestibility, pH, or gas volume. All EFAs increased (p &lt; 0.001) the propionate molar proportion and decreased (p &lt; 0.001) the acetate-to-propionate ratio. EFA2 decreased (p &lt; 0.05) the acetate proportion by 3.3% compared to the control. In conclusion, EFA1 is recommended as an effective nutritional intervention to mitigate CH4 emissions and optimize ruminal fermentation in dairy cows.

Ruminal fermentation characteristics and methane emissions with the addition of Cassia spp. extract to a total mixed ration based on corn stover

This study evaluated the effects of the addition of four different Cassia species extracts to a total mixed ration (TMR) composed of corn stover on the characteristics and methane emissions in vitro. The design used was a randomized complete block design (RCBD), with the source of inoculum derived from rumen fluid taken from three sheep serving as groups in the treatment. The concentrations of Cassia siamea, C. fistula, C. surattensis, and C. spectabilis extracts added to the TMR based on corn stover were 2 mg/mL. Every treatment was repeated three times. The variables observed were in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD); microbial protein synthesis (MPS); volatile fatty acid (VFA) content; acetate, propionate, and butyrate levels; gas production; methane; and populations of methanogen bacteria and protozoa. The study showed that the addition of Cassia spp. extract to TMR at a dose of 2 mg/mL increased (P &lt;0.05) the IVDMD, IVOMD, N-NH3, and total bacterial population but decreased the total and partial VFA, methanogenic bacteria, and the number of protozoa. The addition of C. surattensis extract reduced methane emissions by 13.11% compared with those of the controls based on the percentage of total gas or 14.9% based on mL/g DOM (P &lt;0.05). In conclusion, Cassia spp. extract is a potential agent for reducing methanogenesis in the rumen.

Mycotoxins evaluation of total mixed ration (TMR) in bovine dairy farms: An update

The total mixed ration (TMR) is currently a widespread method to feed dairy cows. It is a mixture of raw fodder and concentrate feed that can be contaminated by several mycotoxins. The main aim of this paper was to provide a critical review on TMR mycotoxin occurrence and its usefulness to monitor and control them on-farm. Aflatoxins, zearalenone, deoxynivalenol, T-2 toxin and fumonisins (regulated mycotoxins) are the most prevalent mycotoxins evaluated in TMR. Nonetheless, several emerging mycotoxins represent a health risk at the animal level regarding their prevalence and level in TMR. Even when measured at low levels, the co-occurrence of mycotoxins is frequent and synergistic effects on animal health are still underevaluated. Similar to the animal feed industry, on-farm plans monitoring mycotoxin feed contamination can be developed as a herd health management program. The estimated daily intake of mycotoxins should be implemented, but thresholds for each mycotoxin are not currently defined in dairy farms.