M.H.P.M. Narciso, A.R. Wolfe, R.R.E. Uwiera
et al.
ABSTRACT: Although the importance of pH and short-chain fatty acids (SCFA) on rumen development are well-known, their impact on the small and large intestine are unclear. This study investigated how single-dose ruminal infusions with high or low SCFA concentrations and high or low pH affect calves' productivity, as well as physiological parameters associated with hindgut acidosis at 3 time points in 49 d. Holstein bull calves (n = 32) were individually housed and fed milk replacer (900 g/d) twice daily and calf starter and water ad libitum. At d 10 ± 3 of life, the rumens were fistulated and cannulated. At d 14 of life, calves were grouped by BW and assigned in a 2 × 2 factorial arrangement of treatments: high or low SCFA concentration (285 vs. 10 mM) and high or low pH (6.2 vs. 5.2), creating 4 treatment groups: high SCFA concentration, high pH (HS-HP); high SCFA concentration, low pH (HS-LP); low SCFA concentration, high pH (LS-HP); and low SCFA concentration, low pH (LS-LP). On d 21, 35, 49, feces were sampled to calculate apparent total-tract digestibility, determinate organic acid concentrations (i.e., SCFA, branched-chain fatty acid [BCFA], and lactic acid), and pH. Afterward, the rumen was evacuated and underwent a single-dose infusion for 4 h with 1 of 4 treatment buffers. After completion of rumen infusion on d 49, calves were killed and the tissue weight and length were recorded, along with the digesta pH of the rumen, duodenum, jejunum, ileum, cecum, colon, and rectum. Data were analyzed with main factors as fixed effects and repeated measures for weekly measurements. Treatments did not affect performance parameters such as feed intake, ADG, apparent total-tract digestibility and gut measurements. In the duodenum, jejunum, and ileum, HS-HP had a greater digesta pH than LS-HP, whereas the hindgut digesta pH was only affected by the SCFA concentration. A high SCFA concentration increased the concentration of colonic isovaleric acid and fecal BCFA, whereas only colonic acetic acid and fecal lactic acid concentrations were affected by treatment. Fecal SCFA and BCFA concentrations increased mainly on d 35. In summary, 4 h of physiological buffer infusion in the rumen does not change apparent total-tract digestibility and gut measurements but does affect hindgut fermentation parameters (i.e., organic acid concentrations and digesta pH). In addition, calves can experience increased risks of hindgut acidosis around 35 d of life.
ABSTRACT: The objective of this study was to investigate the interaction of ruminal inoculum type (obtained from high- or low-CH4-emitting-phenotype cows) and potent antimethanogenic compounds (AMC), including bromoform (CHBr3), 3-nitropropionic acid (3NPA), chloroform, and Rhodophyta macroalga (RM) on in vitro gas production, ruminal fermentation, and microbial composition parameters. Sixty-eight mid-lactation Holstein cows were initially screened for their enteric CH4 emissions. Out of these 68 cows, 2 were designated as high- (HM, 24.8 ± 0.05 g CH4/kg of DMI) and 2 as low- (LM, 14.8 ± 0.45 g CH4/kg of DMI) CH4 emitters. These cows were used as inoculum donors for the in vitro experiment. In vitro batch-culture incubations were carried out for 24 h. The experiment was a 2 × 5 factorial arrangement design with inoculum and inhibitor treatments as independent variables and their interaction included in the model. For gas production parameters, the AMC × inoculum type (INOC) interactions were significant for total gas production, CH4 yield (g/mg of TMR), and CH4 concentration in total gas. The low-CH4 inoculum (LMI) resulted in similar CH4 concentration in total gas as the high-CH4 inoculum (HMI) for the negative control treatment (TMR + LMI or HMI inoculum with no AMC added). Total gas production was 21% lower for HMI when compared with LMI, regardless of the treatment. Acetate and propionate molar proportions and their ratio also had a significant AMC × INOC interaction in the current study. The inclusion of all AMC resulted in a decrease in acetate and an increase in propionate and butyrate molar proportions. Of the studied inhibitors, 3NPA tended to result in a greater CH4 reduction, reduced acetate, and increased propionate concentrations when combined with LMI, rather than with HMI. A macroalgae inhibitor in combination with HMI, but not LMI, resulted in lower CH4 and higher propionate concentration. Both LMI inoculum and inclusion of each AMC resulted in increased butyrate molar proportions. There was no significant INOC × AMC interaction for estimates of methanogenic activity of methanogenic archaea. Inoculum from low-CH4-phenotype cows resulted in higher gene copy number of Methanobrevibacter ruminantium and Methanosphaera stadtmanae. In the bacterial community, 22 taxa had a significant interaction with INOC. Each AMC differentially affected methanogens and individual bacteria, altering H2 fluxes. Regardless of the inoculum, CHBr3 and 3NPA altered both methanogenic and bacterial communities to a greater extent than the rest of the AMC. The combination of LMI with 3NPA and HMI with RM resulted in a greater CH4 reduction than HMI with 3NPA and LMI with RM, indicating that a different AMC may be more effective in reducing enteric CH4 in HMI versus LMI. These results indicate that the synergistic effect between AMC and INOC are possible; however, due to the difficulty in classification of INOC as LMI or HMI, results of the study should be interpreted with caution.
ABSTRACT: The objective was to evaluate the fit statistics for the predictions of ruminal outflow of protein fractions and EAA by the NRC, National Academies of Sciences, Engineering, and Medicine (NASEM), Cornell Net Carbohydrate and Protein System (CNCPS), and NittanyCow (NC) models in lactating dairy cows. Sixty-seven studies published in English between 1984 and 2020 with 251 treatment means were used for analysis. Lactational performance (DMI, DIM, milk yield, milk fat and true protein, and BW data), dietary nutrient composition (CP, NDF, ether extract, and ash), and ruminal outflow of total AA, microbial N, nonammonia nonmicrobial N, and individual EAA determined by omasal or duodenal digesta-sampling techniques were extracted from publications and used in the analysis when available. Production and dietary nutrient composition data reported in the studies were used as inputs to predict ruminal outflows of those same variables using NRC, NASEM, CNCPS, and NC models. For all nutritional models, dietary concentration (% DM) of CP was identical or allowed to vary by 0.5 percentage units maximum to that reported in the studies. Fit statistics and performances of nutritional models were assessed using Lin's concordance correlation coefficient (CCC), root mean squared error (RMSE, g/d and % of observed), as well as mean and linear biases. Models performed similarly when predicting ruminal total AA outflow, with CCC ranging from 49% to 57% and RMSE ranging from 19% to 30% of observed. Predictions of ruminal microbial CP (MicP) and nonammonia nonmicrobial CP (NANMCP) outflows had CCC ranging from 43% to 60% and RMSE ranging from 24% to 34% of observed. Predictions of Lys, Met, and His had CCC ranging from 38% to 62% and RMSE ranging from 23% to 40% observed. Overall, model-fit statistics indicated superior performance of NRC, NASEM, and NC in predicting all individual EAA outflows compared with CNCPS (except for Leu in NC). NittanyCow and NASEM, respectively, demonstrated superior performance in predicting total AA compared with NCR and CNCPS. Additionally, NC was superior to NRC and NASEM, which in turn were superior to CNCPS, in predicting ruminal MicP outflow. Both NRC and NC were superior to NASEM and CNCPS in predicting ruminal NANMCP outflow. The NASEM model was outperformed by NRC, CNCPS, and NC in predicting ruminal nonammonia N outflow. Mean and observed biases of concern (i.e., >5.0% of observed) were identified across all models, and these biases should be considered by nutritionists when balancing and evaluating rations targeting individual EAA in high-producing dairy cows.
ABSTRACT: Growing evidence demonstrates that the 4-kingdom intestinal microbiota (FKIM) play a critical role in improving the body's immune processes. Three batches of experiments were conducted to study the effects of infant formula–based powder (IFBP) containing milk fat globule membrane (MFGM), human milk oligosaccharides, and probiotics, respectively, on the FKIM of suckling rats, with the IFBP serving as the control. Compared with the control, 3 functional components could increase the body weight and improve the composition of FKIM. Notably, suckling rats supplemented with MFGM had significantly higher abundance and number of cornerstone species across the FKIM in feces than those in the other groups, and the levels of immune factors in serum were also significantly increased. After MFGM intervention, the abundance of cornerstone species of 99 genera in the feces was significantly correlated with the levels of immune factors in the serum. Among the cornerstone species, there are 11 bacteria, 6 eukaryotes, 2 archaea, and 1 virus that serve as biomarkers to distinguish the fecal microbiota of suckling rats fed with IFBP containing and not containing MFGM. Milk fat globule membrane can improve immunity by regulating functional pathways such as NOD-like receptor signaling and primary immunodeficiency. Milk fat globule membrane can stabilize the cornerstone species in the suckling rats' feces and enhance their immune ability by modulating the intestinal cornerstone species related to serum immunity, and their functional pathways, providing a theoretical basis for developing infant formula with immune-regulating functions.
ABSTRACT: Probiotics and synbiotics can mitigate the negative health consequences of early-life antibiotic exposure. This study aimed to determine whether supplementation with Bifidobacterium longum ssp. infantis 79 (B79) or synbiotics composed of B79 and 2′-fucosyllactose (2′-FL) could mitigate the negative impact of ceftriaxone exposure in early life. We found that antibiotic-treated mice exhibited lower BW, crypt depth, short-chain fatty acid content, and α-diversity indices at weaning, whereas they had increased relative abundance of opportunistic pathogens (such as Enterococcus and Staphylococcus) and decreased relative abundance of intestinal commensal bacteria. Supplementation with B79 and 2′-FL revived these antibiotic-induced negative effects and reduced the mRNA expression of IL-6, IL-12p40, and TNF-α in the spleen at weaning. Moreover, B79 and 2′-FL supplementation persistently improved crypt depth, propionic acid synthesis, and IgG and secretory IgA production, as well as revived the gut microbiota structure and composition in adulthood. Overall, our study suggests that early-life supplementation with B79 alone or in combination with 2′-FL can mitigate ceftriaxone-induced negative effects on the gut microbiota and intestinal and immune development of mice, and these improvements can partially last into adulthood.
Miguel Chirivi, Ursula Abou-Rjeileh, Jeff Gandy
et al.
ABSTRACT: Periparturient dairy cows exhibit intense lipolysis driven by reduced DMI, enhanced energy needs, and the loss of adipose tissue (AT) insulin sensitivity. Extended periods of low insulin sensitivity and negative energy balance induce lipolysis dysregulation, leading to increased disease susceptibility and poor lactation performance. Chromium (Cr) supplementation improves systemic insulin sensitivity, whereas palmitic acid (PA) increases energy availability for milk production. However, the effect of supplementing Cr and PA alone or in combination on insulin sensitivity in AT is unknown. A total of 32 multiparous cows were used in a randomized complete block design experiment and randomly assigned to one of 4 diets fed from 1 to 24 DIM: a control diet with no supplementation (CON, n = 8); the Cr diet (Cr propionate at 0.45 mg/kg Cr/kg DM, n = 8); the PA diet (1.5% DM, n = 8); or Cr+PA (n = 8). Plasma samples were collected at −13 ± 5.1 d prepartum (PreP), and at 14.4 ± 1.9 d (PP1) and 21 ± 1.9 d (PP2) after calving for quantification of albumin, BHB, BUN, calcium, cholesterol, glucose, nonesterified fatty acids (NEFA), total protein, iron, transferrin, triglycerides, and oxylipids. Subcutaneous AT (SCAT) explants were collected at PreP, PP1, and PP2 and incubated in the presence of the lipolytic agent isoproterenol (ISO = 1 µM, BAS = 0 µM) for 3 h. The antilipolytic effect of insulin (1 µL/L) on SCAT explants was evaluated during ISO stimulation (ISO+INS). Lipolysis was quantified by glycerol release in the medium (nmol glycerol/mg AT). Macrophage infiltration and adipocyte size were measured using hematoxylin and eosin-stained AT sections and immunohistochemistry. The Cr diet tended to reduce postpartum NEFA concentrations when compared with CON, PA, and Cr+PA. Likewise, Cr increased the percentage of large adipocytes (>9,000 µm2) postpartum compared with other diets. In line with higher lipid content, Cr-fed cows had higher ex vivo BAS lipolysis at PP2 when compared with PA and Cr+PA. Isoproterenol induced higher lipolysis at PP1 and PP2, but it was not affected by Cr and PA. The ISO+INS treatment reduced lipolysis by 29.91% ± 11% in Cr compared with ISO. In contrast, ISO+INS did not affect ISO lipolysis in CON, PA, and Cr+PA. Plasma transferrin was reduced by Cr. At PP2, PA cows had 3.3-fold higher macrophage infiltration in SCAT when compared with CON and Cr. Plasma 9-hydroxyoctadecadienoic acid (HODE) and 9-oxo-octadecadienoic acid (oxoODE) were increased by Cr+PA. Palmitic acid increased plasma 13-oxoODE and Cr increased the ratio of 13-HODE to 13-oxoODE. Palmitic acid increased 5-iso prostaglandin F2α-VI. Our results demonstrate that supplementing Cr during the immediate postpartum enhances SCAT insulin sensitivity and lipid accumulation. Further studies should determine the effects and mechanisms of action of Cr and PA on AT lipogenesis, adipogenesis, and their impact on lactation performance.
Tony C. Bruinjé, Emma I. Morrison, Eduardo S. Ribeiro
et al.
ABSTRACT: The objective of this prospective cohort study was to determine if progesterone (P4) profiles differed between dairy cows with or without inflammatory disorders early postpartum. A total of 708 cows from 2 commercial herds were enrolled 3 wk before parturition and examined for clinical health disorders (difficult calving, retained placenta, metritis, displaced abomasum, mastitis, or lameness) until 5 wk postpartum. Serum haptoglobin (Hp) was measured in blood at 2 and 6 DIM (range ±2 d); metritis was assessed at 4, 8, 11, and 15 DIM; and purulent vaginal discharge and endometritis (≥6% PMN in endometrial cytology sampled by cytobrush) were assessed at 35 ± 3 DIM. As Hp ≥0.8 g/L or endometritis were associated with ovarian dysfunction in previous studies, cows with serum Hp ≥0.8 g/L at either time point and endometritis, regardless of clinical disease, were classified as the cohort with inflammatory disorders (INFLAM; n = 139). Clinically healthy cows without difficult calving, with singleton birth, with Hp <0.8 g/L at both sampling times, without endometritis or purulent vaginal discharge, and BCS ≥3.00 (1 to 5 scale) were classified as healthy (n = 133). Cows with only one of the 2 conditions (high Hp or endometritis) were excluded. Cohorts had serum P4 measured twice weekly from 35 to 70 DIM (±3 d), and the first detected luteal phase (LP) during the sampling period was defined as the period from onset of luteal activity (P4 increase to ≥1 ng/mL) until decline of P4 to <1 ng/mL. The odds of prolonged LP (≥21 d long), average LP length, peak P4, and time to P4 decline (hazard rate) were analyzed using multivariable mixed logistic, linear, or Cox proportional hazard regression models including INFLAM status, parity, sampling day (when applicable), and herd as a random effect considering the covariates of season, milk yield at first DHIA test, and DIM at onset of cyclicity or LP length (when applicable). Cows with INFLAM had greater odds of prolonged LP (LSM ± SEM; 67% vs. 37% ± 7%), greater average LP length (17 vs. 15 ± 2 d), lesser P4 at d 4 (4.6 vs. 5.5 ± 0.3 ng/mL) and d 7 (6.0 vs. 7.7 ± 0.3 ng/mL) of the LP, and lesser peak P4 (6.9 vs. 8.2 ± 0.3 ng/mL) during the LP than healthy cows. Status of INFLAM was associated with time to P4 decline in multiparous but not primiparous cows; the LP of INFLAM multiparous cows was less likely to have luteolysis (P4 decline) by d 14 (adjusted hazard ratio [AHR] and 95% CI: 0.54; 0.31 to 0.94) or by d 21 (AHR: 0.32; 0.12 to 0.84) than in healthy multiparous cows. In conclusion, postpartum cows with markers of systemic inflammation at wk 1 and uterine inflammation at wk 5 had altered luteal function (prolonged LP and lower P4 concentrations) before first breeding, which is a possible pathway linking postpartum health disorders and reduced fertility.
Thomas Le Page, Ahmed Ferchiou, Simon Dufour
et al.
ABSTRACT: Mastitis is one of the most common diseases of dairy cattle. It has a high impact on-farm economy, farmers' working time, and antimicrobial usage (AMU). Selective dry cow therapy (SDCT) is an effective means of reducing AMU without negatively affecting udder health. The objective of our study was to evaluate the impact of SDCT implementation on farmer income, working time, and AMU, using a bioeconomic model. A stochastic dairy simulation model (DairyHealthSim) based on a weekly model was used to simulate herd dynamics, reproduction, milk production, culling decisions, health outcomes, and the management of health events. A specific module was developed for the simulation of quarter-level IMI acquisition and elimination during the lactation and dry-off periods, and 25 different farm settings were defined to represent herds with various udder health situations. We then defined 20 scenarios of SDCT by combining both the use of different thresholds of SCC and milk bacteriology for treatment allocation and the use of internal teat sealant (ITS). All SDCT protocols had little effect on farmer income, and we identified some protocols with a positive farm gross margin (up to Can$15.83/dried cow; at time of writing, Can$1 = US$0.72). We also found that adding an ITS to all cows led to greater economic gain. The application of SDCT had little effect on farmers' working time, except when milk bacteriology was used for decision making. Antimicrobial treatment to all cows above 200,000 cells/mL at last control, with the use of ITS on all cows, seems a good choice in most dairy farms. These findings could be used to convince farmers to adopt this strategy at dry-off.
Victor B. Pedrosa, Shi-Yi Chen, Leonardo S. Gloria
et al.
ABSTRACT: Identifying genome-enabled methods that provide more accurate genomic prediction is crucial when evaluating complex traits such as dairy cow behavior. In this study, we aimed to compare the predictive performance of traditional genomic prediction methods and deep learning algorithms for genomic prediction of milking refusals (MREF) and milking failures (MFAIL) in North American Holstein cows measured by automatic milking systems (milking robots). A total of 1,993,509 daily records from 4,511 genotyped Holstein cows were collected by 36 milking robot stations. After quality control, 57,600 SNPs were available for the analyses. Four genomic prediction methods were considered: Bayesian least absolute shrinkage and selection operator (LASSO), multiple layer perceptron (MLP), convolutional neural network (CNN), and GBLUP. We implemented the first 3 methods using the Keras and TensorFlow libraries in Python (v.3.9) but the GBLUP method was implemented using the BLUPF90+ family programs. The accuracy of genomic prediction (mean square error) for MREF and MFAIL was 0.34 (0.08) and 0.27 (0.08) based on LASSO, 0.36 (0.09) and 0.32 (0.09) for MLP, 0.37 (0.08) and 0.30 (0.09) for CNN, and 0.35 (0.09) and 0.31(0.09) based on GBLUP, respectively. Additionally, we observed a lower reranking of top selected individuals based on the MLP versus CNN methods compared with the other approaches for both MREF and MFAIL. Although the deep learning methods showed slightly higher accuracies than GBLUP, the results may not be sufficient to justify their use over traditional methods due to their higher computational demand and the difficulty of performing genomic prediction for nongenotyped individuals using deep learning procedures. Overall, this study provides insights into the potential feasibility of using deep learning methods to enhance genomic prediction accuracy for behavioral traits in livestock. Further research is needed to determine their practical applicability to large dairy cattle breeding programs.
Carlos E.C. Consentini, Leonardo F. Melo, Tattiany Abadia
et al.
ABSTRACT: The present study compared 2 strategies to initiate a progesterone (P4)-based timed artificial insemination (TAI) protocol for lactating dairy cows: only GnRH or estradiol benzoate (EB) plus GnRH (EB+GnRH). Lactating Holstein cows (n = 487; 184 primiparous and 303 multiparous) from 2 commercial dairy herds were used for their second or greater services postpartum. Each week, cows that were nonpregnant at the pregnancy diagnosis 32 d after a previous AI were randomly assigned to 1 of 2 experimental groups that differed only in the strategy to initiate (d 0) the TAI protocol. On d 0, every cow received a 2.0-g P4 implant; in the EB+GnRH group, cows were treated with 2.0 mg i.m. of EB and 16.8 µg i.m. of the GnRH analog buserelin acetate, whereas in the GnRH group, cows received only 16.8 µg i.m. of GnRH. On d 7 after the initial treatment, 0.530 mg i.m. of cloprostenol sodium (PGF) was administered in all cows, followed by a second dose on d 8, concomitant with 1.0 mg i.m. of estradiol cypionate and P4 implant withdrawal. The TAI was performed on d 10 (48 h after P4 device withdrawal) in both experimental groups. Only conventional Holstein semen was used throughout the study. The percentage of cows with corpus luteum (CL) on d 0 (73%) and overall ovulation rate after d 0 (54%) did not differ between groups. The CL regression between d 0 and the first PGF treatment was greater in the EB+GnRH group than the GnRH group (42% vs. 31%). Consequently, the proportion of cows with CL at PGF was greater when only GnRH was used on d 0 compared with EB+GnRH (86% vs. 82%), and the mean number of CL at PGF was greater (1.23 vs. 1.11). The expression of estrus near TAI was greater in GnRH group (84% vs. 77%), and cows showing estrus had greater (44% vs. 10%) pregnancy per AI (P/AI) on d 32 for both treatments. We found no effect of the presence of CL on d 0 or at PGF, nor of ovulation after d 0 or CL regression between d 0 and d 7 on fertility. However, fertility was critically impaired when cows did not have CL at both times, d 0 and at PGF treatment. We did not observe any interaction between treatment and other variables, and the P/AI was similar in cows receiving EB+GnRH or only GnRH on d 0 (37.8% vs. 36.6%). In summary, although there was no detectable difference in P/AI between treatments, this study demonstrated potential negative physiological outcomes caused by EB treatment on d 0 (greater incidence of luteolysis after d 0 and fewer cows with CL at PGF treatment). Overall, we found no benefit of adding EB at the initiation of a P4-based TAI protocol on fertility compared with using GnRH alone, despite differences in ovarian dynamics and expression of estrus.
ABSTRACT: The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 yr ago. To provide evidence for the existence of one or more autocrine factors, 10 multiparous cows in late lactation were quarter-milked for 7 d. Following this baseline period, the right front quarter of each cow was left unmilked, and the other quarters were milked for 7 d. Before the last milking of that period, milk (mammary secretions) was collected aseptically from both front quarters. After that milking, 250 mL of the collected samples were infused in the cows' respective rear quarters. No quarters were milked for the following 7 d (milk stasis period), and quarter milking was then resumed in all quarters for the last 7 d of the experiment (remilking period). Quarter milk samples were collected during the baseline period, before the milk stasis period, and during the remilking period. These samples were used for measuring milk components and the concentration of involution markers (SCC, BSA, and lactoferrin). Samples of mammary secretions were collected manually from the quarters during the milk stasis period for involution marker determination. We extracted RNA from samples collected from front quarters before the last milking before the milk stasis period for microRNA (miRNA) determination. As anticipated, the longer milk stasis period implemented for the right front quarter resulted in a more advanced involution than in the left front quarter, based on the concentration of involution markers in the mammary secretions, lower milk production recovery, and changes in milk composition during the remilking period. All 3 involution marker concentrations in the mammary secretions increased in both rear quarters, but were greater in the right quarter secretions than in the left quarter secretions. Resuming milking reinitiated milk production in all quarters, but milk production recovery in the right rear quarters was less robust than that in the left rear quarters (54.3 ± 1.4% vs. 61.6 ± 1.4%, respectively). Milk from the quarters infused with mammary secretions (right rear) had a lower lactose content, but a higher milk protein content and higher SCC than the quarters infused with milk. We detected a total of 359 miRNAs, 76 of which were differentially expressed in milk and mammary secretions. Expression of bta-miR-221 and bta-miR-223 was upregulated in mammary secretions 34- and 40-fold, respectively. The results of the present experiment support the contention that milk stasis leads to the accumulation of one or more factors that trigger involution. The results also indicate that milk stasis leads to changes in the miRNA profile of the milk, but whether such changes are a cause or a consequence of the involution process remains to be established.
ABSTRACT: Surplus dairy calves often arrive at veal and dairy-beef rearing facilities with health and blood metabolite level abnormalities, which can affect their welfare and performance, predisposing them to future health challenges. The objective of this randomized controlled trial was to investigate the effects of transport duration and age at the time of transport on blood parameters in surplus dairy calves following 6, 12, or 16 h of continuous road transportation. All surplus calves from 5 commercial dairy farms in Ontario were enrolled and examined daily before transport (n = 175). On the day of transportation, calves were weighed, blood sampled, and randomly assigned to 6, 12, or 16 h of transportation. Blood samples were then collected immediately after transportation, as well as 24, 48, and 72 h thereafter. Serum was analyzed at a provincial diagnostic laboratory for nonesterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), creatine kinase (CK), cholesterol, and haptoglobin. In addition, blood gas and electrolyte values were also assessed at the time of sample collection. Mixed models with repeated measures were used to assess the effects of transport duration, breed, sex, transfer of passive immunity status, weight before transportation, and age at transportation on blood parameters. Immediately following transportation, NEFA and BHBA were greater for calves transported for 12 h (Δ = 0.22 mmol/L NEFA, 95% CI = 0.15 to 0.30; Δ = 0.04 mmol/L BHBA, 95% CI = 0.02 to 0.06) and 16 h (Δ = 0.35 mmol/L NEFA, 95% CI = 0.27 to 0.42; Δ = 0.10 mmol/L BHBA, 95% CI = 0.08 to 0.11) compared with calves transported for 6 h. Glucose was lower immediately following transportation in calves transported for 16 h compared with 6 h (Δ = −15.54 mg/dL, 95% CI = −21.54 to −9.54). In addition, pH and HCO3− were lower in calves transported for 12 (Δ = −0.09 pH, 95% CI = −0.13 to −0.05; Δ = −1.59 mmol/L HCO3−, 95% CI = −2.61 to −0.56) and 16 h (Δ = −0.07 pH, 95% CI = −0.12 to −0.03; Δ = −1.95 mmol/L HCO3−, 95% CI = −2.95 to −0.95) compared with calves transported for 6 h. Calves transported between 15 and 19 d of age had a higher concentration of cholesterol and CK (Δ = 0.27 mmol/L cholesterol; 37.18 U/L CK) compared with 2- to 6-d-old calves, and calves 12 to 14 d old had greater reduction in HCO3− (Δ = −0.92 mmol/L) compared with 2- to 6-d-old calves. These findings show that transporting calves for long distances results in lower glucose concentration and suboptimal energy status, and that this effect varies based on the calf's age.
A. Edvardsson Rasmussen, R. Båge, K. Holtenius
et al.
ABSTRACT: When the voluntary waiting period (VWP), defined as the days between calving and when the cow is eligible to receive the first insemination, is extended, high-yielding dairy cows may have better opportunities to regain energy balance before first insemination. This study investigated the effect of an extended (145–215 days in milk [DIM], n = 280) or conventional (25–95 DIM, n = 251) VWP treatment on fertility, disease incidence, and culling rate in cows during their first lactation. The cows were also followed through a second lactation without intervention regarding VWP, during which the farmers could decide when they wished to start the inseminations. This was done in a randomized-controlled study on 16 high-yielding commercial herds in southern Sweden, containing a total of 531 primiparous cows of the Holstein and Red Dairy Cattle breeds. Data from the Swedish national dairy herd recording scheme collected between August 2018 and September 2021 were used in the analysis, including records on breed, calvings, estrus intensity, inseminations, disease, somatic cell count, culling date, and culling reason. During first lactation, more cows receiving the extended VWP treatment showed strong estrus intensity (score 4–5, 55% vs. 48%) and fewer showed moderate estrus intensity (score 3, 35% vs. 43%) at first insemination, compared with cows receiving the conventional VWP treatment. First service conception rate (FSCR) was higher (67% vs. 51%) and number of inseminations per conception (NINS) was lower (1.6 vs. 2.0) during the first lactation for cows receiving the extended compared with the conventional VWP treatment. For disease incidence rate or culling rate expressed as number of events per cow-time in the study, we found no differences between the cows receiving the 2 VWP treatments in any lactation. Calving to first service interval during second lactation was longer (86 vs. 74 d) for cows with extended compared with conventional VWP. In conclusion, primiparous cows with extended VWP showed improved reproductive functions, in the form of higher estrus intensity, greater FSCR, and lower NINS, during the first lactation. However, we observed no apparent effect on these fertility measures during the following lactation (without VWP intervention) and no differences in disease prevalence or culling between cows receiving the 2 different VWP treatments in either lactation. Compliance with the planned VWP treatment was lower for cows with planned extended compared with planned conventional VWP treatment. We studied the “intention-to-treat” effect (i.e., the results for all cows randomized to each treatment regardless of whether the planned VWP was achieved or not) to identify any bias arising due to degree of compliance. However, we found no difference in culling rate between cows randomized to an extended VWP compared with those randomized to a conventional VWP. These findings can be used to support management decisions on VWP length in high-yielding dairy herds.
Cecilia Loza, Hannah Davis, Carsten Malisch
et al.
The sustainability of dairying has been questioned, yet cattle exploit non-food resources (especially forages) and provide key nutrients for consumers’ health. This study, using different forage types, considered milk’s nutritional quality, focusing on fatty acid profiles alongside methane emissions—investigating whether methane can be predicted from milk fatty acids (FAs). Compared with grass/clover/maize silage, cows grazing grass/clover pasture produced milk 70% higher in beneficial omega-3 FAs, which increased by an additional 15% when grazing more diverse pasture. Milk from grazing also had less omega-6 FAs (compared with silage diets), and their ratio with omega-3 FAs fell from 2.5:1 on silage to 1.2:1 when grazing grass/clover and 1.1:1 on diverse pasture. Measured methane emissions (at 8.7 g/kg energy-corrected milk) were lower than published values, and existing models for estimating methane from lactating cows were poor predictors for this dataset. The multiple regression of methane against milk FAs in this study provided predictions with an R<sup>2</sup> of 0.56 for daily emissions and 0.65 relative to milk output. Grazing quality and a diverse pasture with productive cows were potentially beneficial to milk nutritional quality, and our results reinforce the theory that milk fat composition could be an accessible tool for methane prediction; however, they also suggest that more work is needed for alternative production systems.
ABSTRACT: Both ruminal microbial structure and functionality might play a role in inter-individual variation in susceptibility for subacute rumen acidosis (SARA) observed in dairy cows. The aims of this study were to determine whether differences between cows with distinct SARA susceptibility were reflected in distinct (1) ruminal microbial communities, (2) salivary bacterial communities, and (3) fermentative capacity of ruminal microbiota assessed in vitro. To test this hypothesis, rumen samples were collected via an esophageal tube on 21 d postpartum from 38 multiparous Holstein cows, which were classified into 4 groups differing in median and mean time of reticular pH below 6 as well as area under the curve of pH below 6.0. During the 21 d postpartum, all cows within a group fulfilled following criteria: susceptible (S, n = 10; mean or median ≥180 min/d), moderately susceptible (MS, n = 7; 60 min/d < mean time of pH below 6 < 180 min/d, and median time of pH below 6 <180 min/d), moderately unsusceptible (MU, n = 11; 10 min/d < mean < 60 min/d, and median time of pH below 6 ≤30 min/d), or unsusceptible (U, n = 10; median = 0 min/d, and mean <10 min/d). Groups did not differ in total daily dry matter intake nor in total, roughage, or concentrate intake during daily 6-h time intervals. Rumen bacterial α-diversity did not differ among groups, but β-diversity varied and bacterial 16S rRNA gene copy numbers were lower in S compared with U cows. The relative abundance of genera Streptococcus, Sharpea, Prevotellaceae_YAB2003, Succinivibrionaceae_UCG-001, Ruminococcus, and Ruminococcaceae_UCG-001 were higher in S compared with U cows. In contrast, Lachnospiraceae_ND3007 and Oscillospiraceae_V9D2013 were more abundant in U cows. Although pH-associated, inter-animal differences were also observed in the salivary bacteria, common differences in ruminal and salivary bacterial genera were limited. The functionality of the rumen microbiota was evaluated in vitro through exposure of the microbial inoculum of S and U cows to an anaerobic buffer at pH 5.8 and 6.8, in the presence of sterile supernatant of their own and of dry cows' rumen fluid (2 × 2 design). Generally, the S inoculum produced more volatile fatty acids, except at low pH with dry cows' supernatant, where volatile fatty acid production was completely impaired and lactate accumulation was highest. Compared with the microbes of U cows, microbes of S cows showed less fermentative activity in situations with 2 stress factors (low pH and an unfamiliar environment, i.e., rumen fluid supernatant of dry cows).
ABSTRACT: The objective of this study was to investigate the effects of an exogenous enzyme preparation from Aspergillus oryzae and Aspergillus niger on lactational performance of dairy cows. Forty-eight Holstein cows (32 primiparous and 16 multiparous) averaging (± SD) 36.3 ± 8.7 kg/d milk yield and 141 ± 52 d in milk were enrolled in a 10-wk randomized complete block design experiment (total of 24 blocks) and assigned to 1 of 2 treatments: basal diet, no enzyme supplementation (CON) or the basal diet supplemented with 4.2 g/kg dry matter intake (DMI) of an exogenous enzyme preparation containing amylolytic and fibrolytic activities (ENZ). After a 2-wk covariate period, premixes with the enzyme preparation or control were top-dressed daily by mixing with approximately 500 g of total mixed ration. Production data were collected daily and averaged by week. Milk samples were collected every other week, and milk composition was averaged by week. Blood, fecal, and urine samples were collected over 2 consecutive days at 0, 4, 8, 12, and 36 h after feeding during the last week of the experiment. Compared with CON, cows fed ENZ tended to increase DMI and had increased milk concentrations of true protein, lactose, and other solids. Milk fat content tended to be higher in CON cows. A treatment × parity interaction was found for some of the production variables. Primiparous cows receiving ENZ had greater yields of milk, energy-corrected milk, milk true protein, and lactose compared with CON primiparous cows; these production variables did not differ between treatments for multiparous cows. Intake and total-tract digestibility of nutrients did not differ between treatments. Concentrations of blood glucose and total fatty acids were not affected by ENZ supplementation, but β-hydroxybutyrate concentration tended to be greater in ENZ cows. Overall, the exogenous enzyme preparation used in this study increased milk protein and lactose concentrations in all cows, and milk production in primiparous but not multiparous cows. The differential production response between primiparous and multiparous cows was likely a result of a greater increase in DMI with ENZ supplementation in the younger animals.
Erin Massender, Luiz F. Brito, Laurence Maignel
et al.
ABSTRACT: Conformation traits are functional traits known to affect longevity, production efficiency, and profitability of dairy goats. However, genetic progress for these traits is expected to be slower than for milk production traits due to the limited number of herds participating in type classification programs, and often lower heritability estimates. Genomic selection substantially accelerates the rate of genetic progress in many species and industries, especially for lowly heritable, difficult, or expensive to measure traits. Therefore, the main objectives of this study were (1) to evaluate the potential benefits of the implementation of single-step genomic evaluations for conformation traits in Canadian Alpine and Saanen dairy goats, and (2) to investigate the effect of the use of single- and multiple-breed training populations. The phenotypes used in this study were linear conformation scores, on a 1-to-9 scale, for 8 traits (i.e., body capacity, dairy character, fore udder, feet and legs, general appearance, rear udder, medial suspensory ligament, and teats) of 5,158 Alpine and 2,342 Saanen does. Genotypes were available for 833 Alpine and 874 Saanen animals. Averaged across all traits, the use of multiple-breed analyses increased validation accuracy for Saanen, and reduced bias of genomically enhanced breeding values (GEBV) for both Alpine and Saanen compared with single-breed analyses. Little benefit was observed from the use of GEBV relative to pedigree-based EBV in terms of validation accuracy and bias, possibly due to limitations in the validation design, but substantial gains of 0.14 to 0.21 (32–50%) were observed in the theoretical accuracy of validation animals when averaged across traits for single- and multiple-breed analyses. Across the whole genotyped population, average gains in theoretical accuracy for GEBV compared with EBV across all traits ranged from 0.15 to 0.17 (32–37%) for Alpine and 0.17 to 0.19 (40–41%) for Saanen, depending on the model used. The largest gains were observed for does without classification records (0.19–0.22 or 50–55%) and bucks without daughter classification records (0.20–0.27 or 57–82%), which have the least information contributing to their traditional EBV. The use of multiple-breed rather than single-breed models was most beneficial for the Saanen breed, which had fewer phenotypic records available for the analyses. These results suggest that the implementation of genomic selection could increase the accuracy of breeding values for conformation traits in Canadian dairy goats.
ABSTRACT: The addition of Bifidobacterium to goat milk has dual effects on health, for which various inherent nutrients of goat milk are retained and live probiotics are provided. We explored the effect of Bifidobacterium animalis ssp. lactis Probio-M8 (Probio-M8) on fermentation characteristics, formation of organic acid, sensory properties, and storage characteristics of fermented goat milk (with added 4.0% sucrose). Addition of Probio-M8 decreased the fermentation time and significantly increased the content of functional organic acids, such as acetic acid, and functional long-chain unsaturated fatty acids, including linoleic acid, α-linolenic acid, and docosahexaenoic acid. Furthermore, the contents of medium-chain and short-chain fatty acids, which are related to “goaty” flavor, were significantly lower in the Probio-M8 treatment compared with the control. The number of living Probio-M8 decreased from 8.27 log cfu/mL (1.80 × 108 cfu/mL) to 7.94 log cfu/mL (0.79 × 108 cfu/mL) after 28 d of storage. Titratable acidity and pH value did not differ between the control group and experimental group (containing Probio-M8). Sensory evaluation indicated a lower goaty flavor and odor in the Probio-M8 fermented milk. Our results suggest that the addition of the probiotic Probio-M8 could improve the sensory, physicochemical, and functional properties of fermented goat milk.
Istraživan je utjecaj infekcije virusom artritis encefalitisa koza (AEK), kliničkog artritisa i subkliničkog mastitisa na trajanje laktacije, ukupno mlijeko i sastav mlijeka. Istraživanje je provedeno na uzorku od 808 koza pasmine francuska alpska koza s proizvodnih mliječnih farmi u Hrvatskoj. Uzeti su uzorci krvi za serološka testiranja i uzorci mlijeka za detekciju subkliničkog mastitisa. Prisutnost kliničkog artritisa dijagnosticirana je pregledom i palpacijom zglobova. Podaci o laktacijama i proizvodnji preuzeti su od Hrvatske poljoprivredne agencije (HPA). Zasebno su testirani utjecaji AEK infekcije i kliničkog artritisa na ukupno mlijeko, trajanje laktacije i sastav mlijeka (mast, protein, laktoza) pomoću GLM procedure za modele koji su uključivali godinu mjerenja, broj laktacije i subklinički mastitis. Infekcija AEK virusom potvrđena je u 53,72 % koza od ukupnog broja koza. Od ukupnog uzorka 23,08 % inficirano je s AEK i imalo subklinički mastitis bakterijske etiologije. Nadalje 22,47 % od ukupnog broja imalo je klinički artritis. Od ukupnog broja 16,95 % bilo je AEK pozitivno i imalo klinički artritis. Utjecaj infekcije virusom AEK potvrđen je za sva analizirana svojstva u smislu smanjenja proizvodnih rezultata. Klinički artritis je pokazao značajan utjecaj na smanjenje većine proizvodnih vrijednosti osim na ukupno mlijeko, udio (%) masti laktoze i ukupnu laktozu (kg). Subklinički mastitis nije značajno utjecao na trajanje laktacije, kao ni udio (%) i udio masti, proteina i laktoze.