Search Results (35)

The diet of dairy calves can be contaminated with mycotoxins, posing a potential risk to animal health. This case study report aimed to make the first assessment of the presence of multiple mycotoxins in concentrates fed to dairy calves in Brazil. A total of 19 concentrate samples intended for dairy calves were analyzed using liquid chromatography coupled with mass spectrometry. Aflatoxins, deoxynivalenol, and T-2 toxin were not detected in any samples, whereas fumonisins B₁ (FB₁) and B₂ (FB₂) were present in 100% of the samples, with mean concentrations of 2750.1 μg/kg and 834.9 μg/kg, respectively. Zearalenone (ZEN) was detected in 36.8% of samples, with a mean concentration of 929.9 μg/kg. Significant correlations were observed between FB₁ and FB₂ (ρ = 0.978; p < 0.001) and between FB₂ and ZEN (ρ = 0.735; p = 0.05). While the physical form of the concentrate did not influence (p > 0.05) mycotoxin concentrations, a trend was observed for FB₁ (ρ = −0.417; p = 0.07) and FB2 (ρ = −0.395; p = 0.09). These findings highlight the frequent occurrence of Fusarium mycotoxins, likely due to pre-harvest contamination, emphasizing the potential risk of additive or synergistic effects in dairy calves. Full article

The objective of this study was to evaluate the effects of feeding a combination of chicory–plantain silage and supplementing Se yeast on the response of early-lactating ewes to induce subclinical mastitis. Polypay ewes (n = 32) were fed either chicory–plantain silage or grass silage and supplemented with 3.6 mg Se yeast/ewe/day for approximately 2 months prior to the infusion of S. uberis into both mammary glands (i.e., intramammary infection or IMI). The ewes had a typical subclinical mastitis response with an 8-fold increase in milk somatic cell count within 24 h post-IMI, a decrease in milk yield, and changes in all milk components measured. The ewes experienced a mild systemic inflammation post-IMI as determined by an increase in rectal temperature and decrease in feed and water intake and, in blood, by an increase in the concentration of ceruloplasmin, haptoglobin, and myeloperoxidase and a decrease in paraoxonase, Zn, advanced oxidation protein products, and hematocrit with no effect on pro-inflammatory cytokines. No effect of silage type, likely due to a low concentration of secondary compounds, or Se supplementation was detected in response to IMI. In summary, the subclinical mastitis model used was effective in mounting an inflammatory response, although this was mild; however, feeding chicory–plantain silage with a low concentration of secondary compounds and supplementing Se yeast had no significant effect on the response of ewes to mammary infection. Full article

Infrared thermography (IRT) is explored as a non-invasive method for indirectly measuring parameters related to animal performance and welfare. This study investigates a feature extraction method termed the “thermal signature” (TS), a descriptor vector derived from the temperature matrix of an animal’s body surface, representing the percentage distribution of temperatures within predefined ranges. The TS, combined with environmental data, serves as a predictor attribute for machine learning-based classifier models to assess heat stress levels. The methodology was applied to a dataset collected from two groups of five dairy calves housed in a climate-controlled chamber and exposed to two artificial heat waves over 13 days. Data, including IRT measurements, respiratory rate (RR), rectal temperature (RT), and environmental variables, were collected five times daily (from 6 a.m. to 10 p.m., every four hours). Classifier models were developed using random forest (RF), support vector machine (SVM), artificial neural network (ANN), and K-nearest neighbor (KNN) algorithms. The RF models based on RR achieved the highest accuracies, 94.1% for two heat stress levels and 80.3% for three heat stress levels, using TS configurations with six temperature ranges. The integration of TS with machine learning-based models demonstrates promising results for developing or enhancing classifiers of heat stress levels in dairy calves. Full article

This study evaluated the effects of supplementing early-lactation Holstein cows with rumen-protected omega-3 fatty acids (calcium salts) on productive and reproductive performance. Thirty-six multiparous cows were randomly assigned to one of two treatments from 21 ± 2 days before calving to 105 ± 5 days in milk (DIM): a Control group (C) or an Omega-3-supplemented group (O-3), receiving a blend of linseed and fish oil (60:40). Both groups were fed isoenergetic diets, with ground corn as the control supplement. Total dry matter and net energy intake did not differ between treatments. A treatment-by-time interaction was observed for milk yield, with cows in the O-3 group producing more milk than controls at specific time points. Additionally, O-3 cows had higher overall protein yield and improved feed efficiency. No differences were found in body weight, BCS, glucose, insulin, IGF-1, or urea concentrations, but a tendency toward higher plasma NEFA and BHBA concentrations and lower energy balance was observed in the O-3 group. Supplementation increased plasma cholesterol and progesterone concentrations and was associated with a higher proportion of cows being pregnant at 130 DIM. These findings suggest that omega-3 supplementation may improve specific aspects of lactational performance and reproductive efficiency without compromising metabolic status. Full article

Utilizing agro-industrial by-products to feed livestock is crucial for environmental protection and, simultaneously, lowering production and feeding costs. In light of these aims, in this study, two trials were conducted to evaluate the impact of jojoba meal (JJM) on Awassi ewes’ milk properties, nutrient intake, digestibility, and the pre-weaning growth of their nursing lambs. In the first trial, 22 Awassi ewes were divided equally between two experimental diets at random (11 ewes per diet): 0% JJM (CON) and 15% JJM (JJM15) of dietary dry matter (DM). In the second trial, 10 ewes were randomly selected (5 ewes/diet) to assess nutritional digestibility and N balance. The results of trial 1 showed that neutral detergent fiber (NDF), acid detergent fiber (ADF), and ether extract (EE) intake values were greater (p ≤ 0.02) in the JJM15 group compared to the CON group. The total gain and average daily gain (ADG) of the lambs in the JJM15 group were significantly higher compared to those of the CON group (p < 0.05). The average milk yield of nursing ewes was similar between the two dietary groups (p ˃ 0.05). The percentage and yield of solids-not-fat (SNF) in the JJM15 group were significantly higher compared to the CON group. The other milk components, including protein, lactose, fat, and total solids yields, were similar between the dietary groups (p ˃ 0.05). The milk production cost was significantly lower for the JJM15 diet than the CON diet (p = 0.004). Triglyceride levels were lower (p = 0.001) in the JJM15 diet group than in the CON diet group. In trial 2, nutrient digestibility and N balance were not affected (p ≥ 0.073) by the consumption of JJM15. In conclusion, JJM at 15% of dietary DM resulted in no negative effects on the health, performance, or milk quality of Awassi ewes. Most significantly, by lowering the cost of production, our results appear to indicate that this dietary supplement improves economic efficiency. Full article

The present study explored the combined effects of CC (Opuntia stricta [Haw.] Haw.) and full-fat corn germ (FFCG) as a source of supplementary PUFA on milk fatty acid (FA) composition of dairy goats fed elephant grass (EG). Twelve Saanen goats were used in a replicated 4 × 4 Latin square design in a 2 × 2 factorial arrangement of treatments (GC or FFCG as energy sources, and the inclusion or not of CC in the diet as a partial substitute for EG). The proportions of various milk FAs were influenced by CC, FFCG, or both. Significant interactions between CC and FFCG were noted for most trans-C18:1 and CLA isomers. Specifically, including CC in the FFCG-supplemented diet increased the levels of trans-11 C18:1 and cis-9, trans-11 CLA in milk fat, whereas these isomers were unchanged or slightly reduced with CC in the GC diet. Similar patterns were observed for C18:2 n-6, while C16:0 increased with CC in the GC diet. Ratios of trans-C18:1/C18:0 and trans-11 C18:1/C18:0 were notably higher when CC was included in the FFCG-supplemented diet. These findings suggest that CC inhibits the last step of rumen biohydrogenation in dairy goats, enriching milk with trans-11 C18:1 and cis-9, trans-11 CLA when supplementary PUFA is provided in the diet. Full article

This pilot study investigated whether reductions in enteric CH₄ emissions could be obtained without affecting dry matter intake (DMI) when iodoform was mixed into total mixed rations (TMRs). The experiment consisted of four periods of 14 d with four rumen-cannulated Holstein dairy cows. In the pre-period, no iodoform was added to TMR, while either 8, 16, or 20 mg iodoform/kg DM was added to TMR in the remaining periods in a change-over design. However, the experiment was not balanced across treatments and periods due to unexpected animal responses in the second period. Dry matter intake and gas exchange were measured the last 3 d in each period using respiration chambers. Rumen grab samples were collected for microbial analyses on d 14. Dry matter intake was unaffected by the addition of iodoform to TMR at or below 20 mg/kg DMI. Methane and H₂ yields (g/kg DMI) quadratically decreased (up to 46%) and increased (up to 1127%), respectively, with the increasing dose. This pilot study indicated that CH₄ reductions can be obtained with an addition of up to 20 mg iodoform/kg DM in the diets of dairy cows without affecting DMI. However, high iodine concentration in iodoform limits its use in commercial herds within the EU. Full article

Use of pair housing for preweaning calves has shown positive benefits in terms of health and production, with it also being thought to offer social support in times of stress such as when calves are disbudded. Calf disbudding through thermal cautery is a common procedure, with recognized physiological and behavioral implications. This study’s objective was to utilize continuous monitoring accelerometers to compare the impact of disbudding on the behavior of pair and individually housed calves. Data from an all-year-round dairy herd in the southwest of England were collected via an accelerometer (ABS breeder tag, Genus, Cheshire, UK) fitted to a forelimb of a convenience subset of calves (n = 265) within two weeks of age. Data were collected between March and December 2020 and covered the period 7 days prior to disbudding until 30 days post disbudding. Calves underwent thermal cautery disbudding by farm staff using local anesthesia and a systemic nonsteroidal anti-inflammatory drug. Data from 205 calves (125 pair-housed and 80 individually housed) were included in analysis through generalized estimating equations models. The calf activity (p = 0.98), number of lying bouts (p = 0.40), and lying time per day (p = 0.75) were not associated with the housing treatment of the calves. Calf activity was associated with the day compared to disbudding (p < 0.001), with both housing treatments having decreased activity in the days following disbudding, taking approximately 14 days to return to pretreatment levels. Full article

Twenty-four Girolando cows (107 ± 56 days in milk, milk yield 22.0 ± 10.25 kg/d, and 529 ± 103 kg body weight) were used in a completely randomized design. The cows were divided according to the following experimental diets: 1—CON (basal diet with ground dry corn) 2—RCS (diet with total replacement of ground corn by rehydrated corn grain silage) 3—RCSP (diet with total replacement of ground corn by rehydrated corn grain silage + 500 g ton⁻¹ of CINBENZA DP100^®, NOVUS International, Inc (Chesterfield, Missouri, U.S.A.). enzymatic extract of Bacillus licheniformis, protease activity 600 IU g⁻¹). Cows fed RCS + RCSP showed higher DMI, milk yield, and better efficiency (MY/DMI) compared to animals fed CON diet. Cows fed the CON diet had higher fecal concentration, and lower total starch digestibility and milk protein content compared to animals supplemented with RCS + RCSP. Cows fed RCSP showed a 2.96% superiority in total starch digestibility compared to animals fed RCS. Animals supplemented with RCSP presented higher milk yield (17.45%) and milk fat content (13.76%) than cows fed RCS. The inclusion of protease in rehydrated corn silage improved dairy cow performance, enhancing dry matter intake, milk yield, and productive efficiency. It also increased starch digestibility and milk protein and fat content, optimizing nutrient utilization. Full article

This study aimed to compare calcium oxide (CaO) and calcium chloride (CaCl₂) as calcium sources for coconut fatty acid distillate (CFAD) calcium soap (Ca-soap) production and to evaluate the supplementation ratios of unprotected and protected CFAD in dairy rations to optimize rumen function. This research included two steps: (1) assessing the protection strength of Ca-soap made with CaO and CaCl₂ at mole ratios of Ca to CFAD of 1, 1.5, 2, and 2.5; (2) evaluating CFAD supplementation in an in vitro dairy ration study using a 5 × 4 randomized factorial block design. Factor A compared unprotected and protected CFAD ratios of A1 = 100:0, A2 = 75:25, A3 = 50:50, A4 = 25:75, and A5 = 0:100, and factor B compared supplementation levels of B1 = 0%, B2 = 1%, B3 = 2%, and B4 = 3%. CaCl₂ at a 2.5-mole ratio to CFAD produced the lowest acid value and the carboxylic acid (C=O) chemical bond. Complete protection (0:100) exhibited the highest densities of Bacteroides and nutrient digestibility (p < 0.05) without significantly affecting rumen fermentability (p > 0.05). Higher CFAD levels significantly reduced methanogens and protozoa (p < 0.05) without significantly affecting estimated methane production. In conclusion, CaCl₂ at a 2.5-mole ratio to CFAD provided the best protection, and its complete protection in CFAD supplementation optimized rumen function. Full article

This study used a meta-analytic approach to evaluate the effects of dietary supplementation with seaweed on milk yield, milk composition, nutrient digestibility, ruminal fermentation, and enteric methane (CH₄) emissions of dairy cows. Data used in statistical analyses were obtained from 23 peer-reviewed scientific articles. Effect size was assessed using weighted mean differences (WMD) between seaweed-supplemented and control treatments. Dietary supplementation with seaweed decreased (p < 0.05) dry matter intake, milk protein content, milk urea nitrogen, and somatic cell count. In contrast, milk fat content, milk lactose content, and milk iodine increased (p < 0.05) in response to dietary supplementation with seaweed. Dietary supplementation with seaweed did not affect (p > 0.05) nutrient digestibility, total volatile fatty acids, acetate, and propionate. Dietary supplementation with seaweeds increased (p < 0.05) ruminal pH and ruminal concentration of butyrate and valerate. In contrast, lower (p < 0.05) ruminal ammonia nitrogen concentration, acetate/propionate ratio, daily CH₄ emission, CH₄ yield, and CH₄ intensity were observed in response to dietary supplementation with seaweeds. In conclusion, dietary supplementation with seaweed modifies milk composition, improves ruminal fermentation, and decreases enteric methane emissions without negatively affecting milk yield or feed efficiency. Full article

Artisan goat cheeses (AGCs) from four different producers in Coahuila, Mexico, along with a pasteurized goat cheese (C), were subjected to a comprehensive analysis covering production, chemical, microbiological aspects, and texture. The study aimed to discern the impact of feeding practices, seasonality, and manufacturing technology on their properties. Aspects such as the manufacturing production, chemical composition, microbiological load, and texture characteristics were analyzed. The results highlighted a higher protein content in the cheeses from grazing goats (14.51%), while the highest fat (14.25%) and ash (3.27%) contents were found in the cheeses made during spring from stabled goats. Correlations were noted between the protein content and hardness, as well as the acidity and adhesiveness. Most of the analyzed cheeses showed microbiological levels higher than those allowed by national regulations, with counts ranging from 1 to 7.5 Log cfu g⁻¹ for total coliforms, 2.39 to 7.52 Log cfu g⁻¹ for molds and yeasts, as well as 2.16 to 6.53 Log cfu g⁻¹ for Staphylococcus. The findings of this study offer a comprehensive insight of the effects of feeding practices, seasonality, and manufacturing technology on AGC properties, potentially guiding improvements in both production processes and product quality. Full article

Selenium (Se) is an essential micronutrient crucial in various metabolic processes. Dairy production is continually expanding and can supplement the population of regions with low Se. Adding live yeast concentrate (LYC) to cows’ diets can influence milk production, composition, and quality by modulating ruminal microbiota, resulting in increased milk yield and improved nutritional content. This study aimed to assess the enrichment of milk with selenite LYC for a subsequent increase in quality and production in supplemented lactating cows. Twenty-six cows were separated into three groups supplemented with different concentrations of Se for 15 days and different concentrations of LYC (Saccharomyces cerevisiae at 10⁸ CFU g⁻¹). The animals were divided into the following groups with the proposed treatments: Treatment 1 (T1) Control Group with just dry matter intake (DMI); Treatment 2 (T2) DMI + 0.3 mg kg⁻¹ DMI of inorganic selenium + live yeast concentrate (LYC); Treatment 3 (T3) DMI + 0.6 mg kg⁻¹ DMI of inorganic selenium + LYC. The milk was evaluated using physical–chemical, microbiologic, and toxicologic parameters according to Brazilian legislation. The addition of Se and yeast did not alter milk production; however, the application did lead to an increase in milk fat concentration compared with the control group, and no significant variations were observed in other physical–chemical parameters. Regarding the microbiological and toxicological analyses, all the samples presented satisfactory hygienic and sanitary conditions. The Somatic Cells Count from all treatments remained below 500,000 somatic cells mL⁻¹, representing a positive effect of Se. The milk Se content was expected in residual form with the organic selenium being the more bioavailable form throughout the processing chain. The supplementation yielded results similar to those in the literature, highlighting the potential for customized technology and processes in dairy farming in ways that improve production, quality, and sanitation. Full article

The aim of the present research was to study the influence of the calving season in conditions of the upcoming climate changes on the productive traits of dairy cows in Bulgaria. The study was conducted on a cattle farm with a capacity of 500 dairy cows, which were loose-housed in open free-stall barns (shed-type). In the research, 286 lactations of 199 Holstein cattle from the studied farm were included. The cows with the highest average milk yield for lactation—8522.2 kg—calved in the spring, while the cows with the lowest milk yield—8082.7 kg—calved in the summer. Cows that calved in the spring had the highest maximum daily milk yield (lactation peak)—38 kg—whereas cows that calved in the summer had the lowest—35.7 kg. Regarding the composition indicators of milk, fat, and protein content, no significant effect of the calving season was found, but there was a tendency for the lowest values for the percentage of fat in milk to be reported for cows that calved in the summer—3.68%—and the highest for those calved in the spring—3.71%. Regarding the percentage of protein in the milk, the lowest values were observed for cows that calved in autumn—3.19%—and the highest for cows that calved in summer—3.27%. Full article

Dietary particle size is one of the most relevant factors influencing rumen function and the selection of the most palatable components of the total mixed ration (TMR) by cows. The aim of this study was to evaluate the particle size distribution (PSD), homogeneity, sorting level, physically effective NDF (peNDF) content of TMRs, and production performances in Calabrian commercial dairy herds in southern Italy. The research was conducted in 13 farms, including 8 with hay-based TMR and 5 with silage-based TMR. All herds delivered fresh feed once a day. At each farm, the TMRs were examined with the Penn State Particle Separator (PSPS) to determine PSD, homogeneity, and feed sorting at two time points (i.e., at fresh feed delivery = T0 and 24 h after feed delivery = Tf). None of the diets that were evaluated met the recommended PSD, showing an excess of long fraction, very short fraction, or both. The homogeneity was good except for three diets, but particle selection raised some concerns in 85% of the farms due to the preferential consumption of the very short fraction by the cows, with rejection of the long fractions. All the diets analyzed met the Penn State University recommended neutral detergent fiber (NDF) values (>28%) except for one farm’s diet. In three of the TMRs observed, however, the content of peNDF > 8 mm was less than 15%. NDF and peNDF > 8 mm values of TMRs showed statistically significant correlations with milk fat content. Therefore, it is important to evaluate the chemical and physical properties of TMR to provide a consistent diet and prevent feed sorting. Full article