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The use of modern prolific lines of rabbit does in intensive production systems leads to an increase in productivity but also causes a rise in several problems related to the does' health status. Hence, the aim of this study was to investigate the effect of the litter size on the metabolic, inflammatory and plasma amino acid profile in rabbit does. The blood of 30 pregnant does was sampled on the 27th day of pregnancy. The does were retrospectively grouped according to the number of offspring into a high litter size group (HI, does with ≥ 12 kits; n = 16) and a low litter size group (LO, does with ≤ 11 kits; n = 14). Data were subjected to Pearson's correlation analysis. Further, data were analysed in agreement to a completely randomized design in which the main tested effect was litter size. The linear or quadratic trends of litter size on parameters of interests were post hoc compared by using orthogonal contrasts. In addition, compared with the LO group, the HI group had lower levels of glucose (-5%; P < 0.01), zinc (-19%; P < 0.05), albumin (-6%; P < 0.05) and total cholesterol (-13%; P < 0.07), but the total bilirubin level was higher in the HI group (+14%; P < 0.05). Regarding the plasma amino acids, the HI group had lower concentrations of threonine (-15%), glycine (-16%), lysine (-16%) and tryptophan (-26%) and a higher level of glutamic acid (+43%; P < 0.05) compared with the LO group. The exclusively ketogenic amount of amino acids was lower (P < 0.06) in the HI (55.8 mg/100 ml) does compared with the LO does (56.8 mg/100 ml). These results show that a few days before delivery, rabbit does that gave birth to a higher number of offspring had a metabolic profile and an inflammatory status that was less favourable with respect to does who gave birth to a lower number of offspring. Moreover, the plasma amino acid profile points out that there was an enhanced catabolic condition in the rabbit does with a high number of gestated foetuses; it was likely related to the greater energy demand needed to support the pregnancy and an early inflammatory response.

In this study, we investigated associations among subclinical intra-mammary infection (IMI) and quarter-level milk composition, udder health indicators, and cheesemaking traits. The dataset included records from 450 Holstein cows belonging to three dairy herds. After an initial screening (T0) to identify animals infected by Streptococcus agalactiae, Streptococcus uberis, Staphylococcus aureus, and Prototheca spp., 613 quarter milk samples for 2 different sampling times (T1 and T2, 1 mo after T1) were used for analysis. Milk traits were analyzed using a hierarchical linear mixed model including the effects of days in milk, parity and herd, and bacteriological and inflammatory category [culture negative with somatic cell count (SCC)200,000 cells/mL; culture negative with SCC ≥200,000 cells/mL; or culture positive]. All udder health indicators were associated with increased SCC and IMI at both sampling times. The largest effects were detected at T2 for milk lactose (-7% and -5%) and milk conductivity (+9% and +8%). In contrast, the increase in differential SCC (DSCC) in samples with elevated SCC was larger at T1 (+17%). Culture-negative samples with SCC ≥200,000 cells/mL had the highest SCC and greatest numbers of polymorphonuclear-neutrophils-lymphocytes and macrophages at both T1 and T2. Regarding milk cheesemaking ability, samples with elevated SCC showed the worst pattern of curd firmness at T1 and T2. At T2, increased SCC and IMI induced large decreases in recoveries of nutrients into the curd, in particular recovered protein (-14% and -16%) and recovered fat (-12% and -14%). Different behaviors were observed between Strep. agalactiae and Prototheca spp., especially at T2. In particular, samples that were positive for Strep. agalactiae had higher proportions of DSCC (+19%) compared with negative samples with low SCC, whereas samples that were positive for Prototheca spp. had lower DSCC (-11%). Intramammary infection with Prototheca spp. increased milk pH compared with culture-negative samples (+3%) and negative samples that had increased SCC (+2%). The greatest impairment in curd firmness at 30 min from rennet addition was observed for samples that were positive for Prototheca spp. (-99% compared with negative samples, and -98% compared with negative samples with high SCC). These results suggest that IMI caused by Prototheca spp. have detrimental effects on milk technological traits that deserve further investigation of the mechanisms underlying animals' responses to infection.

Dairy cows during the transition period are faced with important physiological changes which include a dysfunctional immune system and an increased inflammatory state. New data are necessary to understand the key factors involved in the immune system regulation. Six dairy cows were sampled during transition period to investigate the leukocyte transcriptome changes and its relationship with blood biomarkers. Blood samples were collected at - 20 ± 2, - 3 ± 1, 3, and 7 days from parturition (DFP). Leukocyte transcriptome was analyzed by deep sequencing technology (Hiseq1000 Illumina, USA). Plasma was analyzed for metabolic biomarkers. Differentially expressed genes (DEG) were used to run an enrichment analysis through the Dynamic Impact Approach (DIA). Considering - 20 DFP as references time, the main KEGG impacted pathways were activated before calving (- 3 DFP) and were connected to lipid metabolism, lipid transport in plasma, and phagosome. The greatest differences were found after parturition with 281 DEG (179 upregulated and 102 downregulated). The activated pathways were mainly related to immunity and endocrine aspects, while metabolic pathways related to lipid and amino acid metabolism were inhibited. Plasma BHBA had a substantial inhibitory impact on KEGG pathways related to DNA replication and cell cycle, while plasma IL-1β had an inhibitory impact on fatty acid elongation in mitochondria and an activated impact in several pathways related to cellular energy metabolism. Overall, this study confirmed that many changes in lipid metabolism and immune competence of the circulating leukocytes occurred in dairy cow around calving. Interestingly, BHBA and IL-1β connected with the transcriptome.

The increased resistance to disease observed after monensin treatment could reflect a reduction of inflammation and oxidative stress. We hypothesised that if monensin supplementation was given before calving, it would help in controlling inflammation, reduce the susceptibility to disease and increase the performance. Fourteen pregnant heifers (PR) and 24 multiparous cows (ML) were randomly assigned to a treated group (Mon) or a control group (Ctr). The Mon group received 32.4 g of monensin in a controlled-release capsule 21 days before calving (expected release rate, 335 mg/d for 95 days). Their health status, rumination activity, and plasma parameters were monitored from –28 to 56 days from calving. The milk yield (MY), milk composition, and cheese-making properties were also monitored. Rumen samples were collected at 30 days from calving to assess the volatile fatty acids composition and investigate immunological parameters. After calving, the Mon group had fewer clinical diseases, an increased rumination time, and a higher MY. Monensin reduced the infiltration of both T and B cells in rumen fluid. In ML, the Mon group had lower levels of β-hydroxybutyrate in the early postpartum period and a lower level of total reactive oxygen species. Of PR, the Mon group had a tendency for lower levels of nonesterified fatty acids, higher levels of ceruloplasmin after the first month of lactation, a tendency for lower levels of paraoxonase, higher levels of γ-glutamyl transferase and higher levels of total reactive oxygen species. Monensin treatment decreased the cheese-making properties in the milk of PR.HighlightsMonensin improved the performance of all the animals and decreased the disease incidence in all of them.Monensin heightened the inflammatory and oxidative stress status and reduced the cheese-making properties in pregnant heifers.Although different effects were seen in cows with different parity, dairy cows generally beneficed of monensin administration. Monensin improved the performance of all the animals and decreased the disease incidence in all of them. Monensin heightened the inflammatory and oxidative stress status and reduced the cheese-making properties in pregnant heifers. Although different effects were seen in cows with different parity, dairy cows generally beneficed of monensin administration.

Metabolic disorders, including hepatic lipidosis and ketosis, severely affect animal health status and welfare with a large economic burden in dairy herds. The gold standard for diagnosing hepatic lipidosis is the liver biopsy, which is impractical and invasive for the screening at farm level. Ultrasound (US) imaging is a promising technique for identifying liver dysfunction, but standardized specifications in physiological conditions are needed. Herein, we described the features of four US measurements, namely the liver predicted triacylglycerol (pTAG) content, liver depth (LD), and portal vein area (PVA) and depth (PVD) and we investigated their associations with a set of hematochemical (HC) indicators in 342 clinically healthy Holstein Friesian dairy cows. Liver pTAG content was negatively associated with hematocrit and positively with globulin, whereas PVA was negatively associated with thiol group levels, and LD positively with ceruloplasmin. We found significant interactions between some HC parameters and parity: in particular, creatinine, thiol groups and globulin for PVA, and aspartate aminotransferase, paraoxonase and ceruloplasmin for PVD. This study offers new insights on variations in liver function occurring after calving and pave the way for the potential use of minimally invasive techniques for prompt detection of metabolic disorders in dairy herds.

An unsupervised machine learning approach (ML) of rumination time (RT) data was used to evaluate metabolic and lactation performance in a cohort of Simmental dairy cows (29) around parturition. The k-means clustering (unsupervised ML) was used to generate clusters based on RT (Hr-Tags; SCR by Allflex) over 24 h from 1 to 7-d post-calving. Two large clusters were obtained: high (High-RT, n = 13) and low (Low-RT, n = 12). Milk production was recorded until 42 d in lactation and milk samples collected weekly. Blood samples were collected from −21 to +28 d relative to calving. Data were subjected to PROC MIXED of SAS. Compared with Low-RT, High-RT cows had lower plasma BHB (3, 7, and 14 d), haptoglobin (3 and 7 d), and non-esterified fatty acids (1 and 3 d). High-RT cows had greater tocopherol from 3 to 28 d, fructosamine and albumin at 7 d, and retinol at 3 and 7 d after calving than Low-RT cows. Compared with multiparous Low-RT, milk production was greater in multiparous High-RT cows, but no differences were detected for primiparous. Only for multiparous, High-RT cows displayed a greater LFI than Low-Rt cows. The close relationship between RT and the physiological state at the onset of lactation supports the use of RT as an indicator of metabolic and inflammatory adaptations to the negative energy balance of cows after parturition. At the farm level, these outcomes provide information to farmers that can be helpful in management decisions for cow health, complementing traditional methods.HIGHLIGHTSThe unsupervised ML applied was able to group cows with different RT increase rates after calving based on differences in plasma biomarkers of energy metabolism, inflammatory response, and liver functionality, particularly in multiparous cows.A quicker increase in RT after calving was associated with a lower inflammatory response, lower lipid mobilisation, and greater milk production.At the farm level, the fine-tuning of specific algorithm in the actual sensors considering the rate of increase of RT after calving can be helpful in management decisions for cow health, complementing traditional methods to better monitor early lactation dairy cows. The unsupervised ML applied was able to group cows with different RT increase rates after calving based on differences in plasma biomarkers of energy metabolism, inflammatory response, and liver functionality, particularly in multiparous cows. A quicker increase in RT after calving was associated with a lower inflammatory response, lower lipid mobilisation, and greater milk production. At the farm level, the fine-tuning of specific algorithm in the actual sensors considering the rate of increase of RT after calving can be helpful in management decisions for cow health, complementing traditional methods to better monitor early lactation dairy cows.

The dry-off of dairy cows represents an important phase of the lactation cycle, influencing the outcome of the next lactation. Among the physiological changes, the severity of the inflammatory response can vary after the dry-off, and this response might have consequences on cow adaptation in the transition period. The plasma protein profile is a diagnostic tool widely used in humans and animals to assess the inflammatory status and predict the outcome of severe diseases. The albumin-to-globulin ratio (AG) can represent a simple and useful proxy for the inflammatory condition. In this study, we investigated the relationship between AG before dry-off and inflammation, metabolic profile, and performance of 75 Holstein dairy cows. Blood samples were collected from -62 (7 d before dry-off) to 28 d relative to calving (DFC) to measure metabolic profile biomarkers, inflammatory variables, and liver function. Daily milk yield in the first month of lactation was recorded. Milk composition, body condition score, fertility, and health status were also assessed. The AG calculated 1 wk before dry-off (-62 DFC) was used to retrospectively group cows into tertiles (1.06 ± 0.09 for HI, 0.88 ± 0.04 for IN, and 0.72 ± 0.08 for LO). Data were subjected to ANOVA using the PROC MIXED program in SAS software. Differences among groups observed at -62 DFC were almost maintained throughout the period of interest, but AG peaked before calving. According to the level of acute-phase proteins (haptoglobin, ceruloplasmin, albumin, cholesterol, retinol-binding protein), bilirubin, and paraoxonase, a generally overall lower inflammatory condition was found in HI and IN than in the LO group immediately after the dry-off but also after calving. The HI cows had greater milk yield than LO cows, but no differences were observed in milk composition. The somatic cell count reflected the AG ratio trend, with higher values in LO than IN and HI either before dry-off or after calving. Fertility was better in HI cows, with fewer days open and services per pregnancy than IN and LO cows. Overall, cows with high AG before dry-off showed an improved adaptation to the new lactation, as demonstrated by a reduced systemic inflammatory response and increased milk yield than cows with low AG. In conclusion, the AG ratio before dry-off might represent a rapid and useful proxy to evaluate the innate immune status and likely the ability to adapt while switching from the late lactation to the nonlactating phase and during the transition period with emphasis on early lactation.

The present experiment aimed to investigate (1) the effect of weaning age on rumen fermentation, dietary intake, growth, and rumination behavior at 20 d after weaning in Simmental calves, and (2) the relationship between rumination time measured by the Hr-Tag rumination-monitoring system (Hr-Tag; SCR Engineers Ltd, Netanya, Israel) and rumen fermentation variables. Ten Simmental calves were randomly assigned at birth to be weaned at 45 (early weaning, EW) or 60 d of age (normal weaning, NW). EW calves were offered 6 L of bulk whole milk/d from d 2 to 38 and 3 L/d from d 39 to 45, while NW were offered 6 L of bulk whole milk/d from d 2 to 53 and 3 L/d from d 54 to 60. Individual calf starter intake was recorded daily and average daily gain (ADG) was calculated taken into account the BW at 6 d after weaning and final BW at 20 d after weaning. On d 20 after weaning, samples of rumen fluid were obtained via an esophageal tube. These samples were used to determine pH and volatile fatty acids (VFAs) concentration. Throughout the entire experiment, the Hr-Tag system continuously recorded the rumination time (RT) by Hr-Tag loggers positioned on the left side of the neck. No treatment differences were detected for total VFAs concentration and molar proportion of acetate, propionate, and butyrate (P > 0.05). Overall in the period -25 to 20 d relative to weaning time, daily RT did not differ between NW and EW calves and it increased around weaning in both groups. Hr-Tags revealed no differences in daily RT pattern (2h-RT) during the 3 d before rumen collection, while during the day (24 h) 2h-RT significantly varied overall in both EW and NW groups. Daily RT measured by Hr-Tags positively correlated to pH (r = 0.98; P

The aim of this study was to investigate changes in the abundance of genes involved in leukocyte function between cows highly specialized for milk production (Holstein, n = 12) and cows selected for meat and milk (Simmental, n = 13). Blood was collected on d 3 after calving in PAXgene tubes (Preanalytix, Hombrechtikon, Switzerland) to measure mRNA abundance of 33 genes. Normalized gene abundance data were subjected to MIXED model ANOVA using SAS (SAS Institute Inc. Cary, NC). Simmental cows had greater transcript abundance of proinflammatory cytokines and receptor genes (IL1B, TNF, IL1R, TNFRSF1A), cell migration- and adhesion-related genes (CX3CR1, ITGB2, CD44, LGALS8), and the antimicrobial IDO1 gene. In contrast, compared with Holstein cows, Simmental cows had lower abundance of the toll-like receptor (TLR) recognition-related gene TLR2, the antimicrobial-related gene LTF, and S100A8, which is involved in cell maturation, regulation of inflammatory processes, and immune response. These results revealed that breed plays an important role in the modulation of genes involved in immune adaptation and inflammatory response, and the immune system of Simmental cows could potentially have a more acute response in early lactation. In turn, this might be beneficial for mounting a more efficient response after calving and allow for a smoother homeorhetic adaptation to lactation.

The anti-hyperlipidemic and anti-inflammatory effects exerted by Aloe on monogastric mammals suggest it as a potential strategy to address the tremendous metabolic alterations that affect dairy cows during their transition to calving. A group of 20 multiparous Italian Holstein dairy cows were housed in freestalls and allocated into two homogeneous groups to receive either 200 g/d of water (CTR) or 200 g/day of Aloe arborescens Mill. whole plant homogenate through a rumen tube (AAM) between &minus, 14 and 14 days from calving (DFC). From &minus, 14 to 35 DFC, the BCS, and milk yield were measured, and blood samples were collected to assess the hematochemical profile. Data underwent ANOVA testing using a mixed model for repeated measurements, including the treatment and time and their interactions as fixed effects. Compared to CTR cows, AAM cows had a less pronounced BCS loss in early lactation (p &lt, 0.01), indicating less mobilization of body reserves. Compared to CTR cows, AAM cows had a lower plasma concentration of nonesterified fatty acids and beta hydroxybutyrate (p &lt, 0.01 and = 0.01 respectively) that, paired with the lower butterfat content and fat/protein ratio in their milk (p = 0.03 and &lt, 0.01 respectively), indicates that Aloe reduced the mobilization of body fats. AAM cows had a reduced concentration of myeloperoxidase in plasma and a lower SCC in milk compared to CTR cows (p = 0.02 for both), indicating an anti-inflammatory effect of Aloe. Furthermore, AAM cows had a lower plasma concentration of ceruloplasmin (p &lt, 0.05) and higher plasma concentration of cholesterol, retinol, and paraoxonase compared to CTR cows (p &lt, 0.01, &lt, 0.01 and &lt, 0.05 respectively), indicating Aloe was effective in mitigating the acute phase response in early lactation. Finally, AAM cows had lower plasma creatinine concentrations around calving (p &lt, 0.05), a lower concentration of plasma bilirubin, and a higher concentration of plasma tocopherol compared to CTR cows (p = 0.01 for both). These data suggest Aloe has anti-hyperlipidemic and anti-inflammatory effects on transition dairy cows that could have ameliorated liver and kidney function disruption and increased the availability of body antioxidants in early lactation.

Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk quality, and plasma liver enzymes in dairy cows. This trial examined 12 lactating Holstein dairy cows using a 3-period × 3-treatment Latin square design. The experimental period was 21 d of mycotoxin exposure followed by 14 d of washout. During treatment periods, cows received one of 3 diets: (1) CTR (control) diet of TMR contaminated with 340.5 µg of DON/kg of dry matter (DM) and 127.9 µg FB/kg of DM; (2) MTX diet of TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (i.e., 733.0 µg of DON/kg of DM and 994.4 µg of FB/kg of DM); or (3) MDP diet, which was MTX diet supplemented with a mycotoxin deactivator product (i.e., 897.3 µg of DON/kg of DM and 1,247.1 µg of FB/kg of DM; Mycofix, 35 g/animal per day). During washout, all animals were fed the same CTR diet. Body weight, body condition score, DM intake, dietary nutrient digestibility, milk production, milk composition and rennet coagulation properties, somatic cell count, blood serum chemistry, hematology, serum immunoglobulin concentrations, and expression of multiple genes in circulating leucocytes were measured. Milk production was significantly greater in the CTR group (37.73 kg/d) than in the MTX (36.39 kg/d) and the MDP (36.55 kg/d) groups. Curd firmness and curd firming time were negatively affected by the MTX diet compared with the other 2 diets. Furthermore, DM and neutral detergent fiber digestibility were lower after the MTX diet than after the CTR diet (67.3 vs. 71.0% and 42.8 vs. 52.3%). The MDP diet had the highest digestibility coefficients for DM (72.4%) and neutral detergent fiber (53.6%) compared with the other 2 diets. The activities of plasma liver transaminases were higher after the MTX diet than after the CTR and MDP diets. Compared with the CTR diet, the MTX diet led to slightly lower expression of genes related to immune and inflammatory functions, indicating that Fusarium mycotoxins had an immunosuppressive effect. Our results indicated that feed contaminated with regular levels of Fusarium mycotoxins adversely affected the performance, milk quality, diet digestibility, metabolic variables, and immunity of dairy cows, and that supplementation with mycotoxin deactivator product counteracted most of these negative effects.

The present experiment aimed to evaluate the potential of the Hr-Tag rumination-monitoring system (Hr-Tag; SCR Engineers Ltd., Netanya, Israel) to describe the variation in rumination activity behavior in pre-weaned calves from 2 until 35 days of age. The study was carried out in a commercial farm and involved 9 Italian Simmental calves (3 females and 6 males). All calves were provided ad libitum access to water and starter throughout the study and were offered 6 L of bulk whole milk/d from an open-bucket starting at day 2 from birth and through 5 weeks. The Hr-Tag system continuously recorded the rumination time (RT) by Hr-Tag loggers positioned on the left side of the neck, and data were summarized in 2-h intervals. RT recorded by Hr-Tag loggers increased (P

Pressure aimed at reducing the use of antibiotics in livestock is steadily increasing. In 2022, the prophylactic use of antibiotics for preventive purposes will be banned in the European Union (EU), including blanket therapy at dry-off. The objective of this study was to evaluate the short- and long-term effects of selectively treating cows with low somatic cell count (SCC) at dry-off using internal teat sealant with or without antibiotic therapy on udder health, milk production, metabolic, and inflammatory conditions through the next lactation. Fifteen Holstein dairy cows without intramammary infections and with SCC less than 200×103 cells/mL at dry-off were enrolled in the study. Cows were abruptly dried off and treated either with antibiotic plus teat sealant (AB) or with teat sealant only (TS). Milk and blood samples were collected on scheduled days from 10 days before dry-off to 28 days after calving. Milk composition and both inflammatory and metabolic profiles were assessed. Fertility and milk production were recorded during the previous and subsequent lactation. Rumination time was monitored from three weeks before dry-off to four weeks after calving. Data were analyzed with PROC MIXED and PROC GLM of SAS software. Total milk production, reproductive performance, rumination time, and mastitis incidence did not differ between groups. Milk yield during the first 120 days after calving was not affected by treatment. Milk composition and SCC were not affected during the first month. Compared with AB, TS had lower plasma calcium at -47 days from calving, gamma-glutamyl transferase at –50, –47, and –42, tocopherol at –65, –50, and –47, and alkaline phosphatase at 3 days from calving. Overall, both metabolic and inflammatory statuses were similar between AB and TS cows with only small transient differences. With the perspective of reducing antibiotic usage in dairy farms, internal teat sealant could be used alone in healthy cows with low SCC with no relevant effects on udder health and immunometabolic profile in the subsequent lactation.

Omnigen-AF (OAF) increases leukocyte functions in immunosuppressed animal models and reduces incidence of infectious diseases in early lactating dairy cows, although its mode of action is still unclear. This study aims to provide a wider perspective of the metabolic effect of OAF to test its potential as a strategy to address metabolic disorders of the transition period. A group of 10 Holstein dairy cows were divided into 2 groups: The treated group (IMS, 5 cows) received 32.5 g of OAF twice a day (65 g d&minus, 1) as top-dress in the morning and afternoon feeds from &minus, 55 to 42 days from calving (DFC), whereas the control group (CTR, 5 cows) received no supplementation. From &minus, 62 to 42 DFC, body condition score, body weight, dry matter intake, rumination time and milk yield were measured, blood samples were collected weekly to assess a wide hematochemical profile and to test white blood cell functions by ex-vivo challenge assays. At 30 DFC, rumen fluid was collected and analyzed for pH, volatile fatty acids composition, urea nitrogen, and lactate contents. Data were submitted to ANOVA using a mixed model for repeated measures, including treatment, time, and their interaction as fixed effects. OAF decreased blood nonesterified fatty acids and beta hydroxybutyrate concentrations and increased rumination time in early lactation. Leukocytes from IMS cows had lower lactate production and lower glucose consumption after ex-vivo stimulation. OAF did not reduce the acute phase response indicators and reduced the blood concentrations of albumin and antioxidants after calving, suggesting impairment of hepatic functions related to protein synthesis and antioxidant management. Nevertheless, the lack of effect on bilirubin and liver enzymes refutes the possibility of severe liver damage occurring with OAF supplementation. Positive effects in reducing mobilization of body fats and ketogenesis and in increasing rumination time after calving suggest OAF effectiveness in preventing metabolic disorders of the transition period.

The present study aimed to investigate blood biomarkers encompassing the metabolic status of Simmental calves, with emphasis on weekly differences in the pre-weaning period. Ten Italian Simmental calves were used for the experiment and were offered 6 L of bulk whole milk/d from an open-bucket starting at day 2 from birth and through 5 weeks. Blood samples were collected at birth and weekly to assess biochemical indicators related to energy metabolism and liver function, minerals, markers of inflammation, and oxidative stress. Body weight (BW), heart girth (HG), and solid feed intake were positively affected by aging. Calves increased solid feed intake consumption after 2 week and reached a BW gain of 28.16 kg at 5 weeks. Most of blood biomarkers were affected by age, mostly concerned the period after birth and day 1, whereas no changes were observed for haptoglobin, urea, β-hydroxybutyrate, Na, and K. The amount of milk fed to calves throughout this study contributes to the maintenance of glucose concentration over time, coupled also with a considerable amount of starter intake. Glucose levels associated to the high ADG (0.89 ± 0.09 kg/d, mean ± SEM) suggest that calves experienced a positive energy balance throughout the entire pre-weaning period. Similar levels of haptoglobin and ceruloplasmin, together with a gradual increase of albumin, reflect good liver functionality and a stable condition regarding the inflammatory status. These results suggest that blood biomarkers of Simmental calves in the pre-weaning phase vary with growing stages.

Subclinical ketosis (SCK) may impair white blood cell (WBC) function and thus contribute to the risk of disease postpartum. This preliminary study investigated changes occurring in the immune system before disease onset to elucidate their role in the occurrence of SCK. A group of 13 Holstein dairy cows were housed in tie-stalls and retrospectively divided into 2 groups based on their levels of β-hydroxybutyrate (BHB) measured in plasma between calving day and 35 d from calving (DFC). Levels of BHB1.4 mmol/L were found in 7 cows (control cows, CTR group) and levels1.4 mmol/L were found in 6 cows at ≥1 of 6 time points considered (cows with SCK, KET group). From -48 to 35 DFC, body condition score, body weight, dry matter intake, rumination time, and milk yield were measured, and blood samples were collected regularly to assess the hematochemical profile and test the WBC function by ex vivo challenge assays. Data were submitted for ANOVA testing using a mixed model for repeated measurements that included health status and time and their interactions as fixed effects. Compared with CTR cows, KET cows had more pronounced activation of the immune system (higher plasma concentrations of proinflammatory cytokines, myeloperoxidase, and oxidant species, and greater IFN-γ responses to Mycobacterium avium), higher blood concentrations of γ-glutamyl transferase, and lower plasma concentrations of minerals before calving. Higher levels of nonesterified fatty acids, BHB, and glucose were detected in KET cows than in CTR cows during the dry period. The effect observed during the dry period was associated with a reduced dry matter intake, reduced plasma glucose, and increased fat mobilization (further increases in nonesterified fatty acids and BHB) during early lactation. A reduced milk yield was also detected in KET cows compared with CTR. The KET cows had an accentuated acute-phase response after calving (with greater concentrations of positive acute-phase proteins and lower concentrations of retinol than CTR cows) and impaired liver function (higher blood concentrations of glutamate-oxaloacetate transaminase and bilirubin). The WBC of the KET cows, compared with CTR cows, had a reduced response to an ex vivo stimulation assay, with lower production of proinflammatory cytokines and greater production of lactate. These alterations in the WBC could have been driven by the combined actions of metabolites related to the mobilization of lipids and the occurrence of a transient unresponsive state against stimulation aimed at preventing excessive inflammation. The associations identified here in a small number of cows in one herd should be investigated in larger studies.

Pegbovigrastim is a long-acting analog of recombinant bovine granulocyte colony-stimulating factor, that promotes and increases the count and functionality of polymorphonuclear cells in dairy cows. The present study aimed to explore, for the first time in Simmental cows, the clinical and hematological effect of pegbovigrastim during the transition period (TP). Cows were randomly assigned into two groups: treated group (PEG, n = 16) received pegbovigrastim at approximately 7 days before expected parturition and within 6 h after calving, and control group (CTR, n = 16) received saline solution. Blood samples were obtained at &minus, 7, 0, 1, 3, 7, 14, 21, and 30 days relative to calving. PEG group showed white blood cells (WBC) count consistently higher compared with CTR group (p &lt, 0.001) until to 3 weeks after calving. Neutrophils remained higher in PEG group (p &lt, 0.001) up to three weeks after calving, compared with CTR group, with slight increment of band cells. Moreover, PEG group displayed a lower index of myeloperoxidase at 1, 3, and 7 days after calving (p &lt, 0.01) compared with CTR. Basophils and lymphocytes showed a similar trend to those observed for neutrophils at 1 day after calving in PEG group. Finally, monocytes remained markedly elevated until 3 days after calving in PEG compared to CTR group (p &lt, 0.001), whereas in PEG group, eosinophils population showed lower percentage values at 1 and 3 days after calving but higher values at 30 days compared with CTR group. PEG group was characterized by lower red blood cells (RBCs) count compared with CTR group (p &lt, 0.05) and higher % of red cell volume distribution width (RDW) from week 2 and mean corpuscular volume (MCV) at 30 days after calving. In addition, the mean platelet volume (MPV) was significantly higher in PEG group at calving, 1, 3, and 7 days after calving compared with CTR group (p &lt, 0.05). For the first time, we described the effect of pegbovigrastim in a breed not specialized exclusively in milk production as Holstein, but with dual purpose (meat and milk), evaluating the complete hematological profile in cows during the transition period. These results provide evidence on the proliferative effect of pegbovigrastim on WBC in Simmental breed highlighting its possible side effect on RBCs.

In the present study, we aimed to investigate the side effects of pegbovigrastim, injected approximately 7 d before parturition and on the day of calving, on a panel of plasma biomarkers to evaluate energy, inflammatory, oxidative, and liver function status. We also addressed treatment responses in different breeds during the transition period. Holstein and Simmental cows were randomly assigned into 2 groups based on expected calving date and according to parity: the treated group (PEG; 14 Holstein and 12 Simmental cows) received pegylated recombinant bovine granulocyte colony stimulating factor (pegbovigrastim, Imrestor; Elanco Animal Health, Greenfield, IN), and the control group (CTR; 14 Holstein and 14 Simmental cows) received saline solution. The PEG or CTR treatments were administered via subcutaneous injection in the scapular region at approximately 7 d (mean 7.80 ± 5.50 d) before expected parturition and within 24 h after calving. Blood samples were collected at -21, -7 (before injection), 1, 3, and 28 d relative to calving. Milk production was recorded at 7, 15, 21, 30, and 42 d. A mixed model with repeated measures was fitted to the normalized data using Proc MIXED of SAS (SAS Institute Inc., Cary, NC). Simmental PEG cows showed higher plasma protein concentrations at 1 and 3 d after calving compared with Simmental CTR and Holstein PEG cows, whereas no differences were detected between Holstein PEG and CTR cows. Albumin was greater at 1 d in Simmental PEG compared with Simmental CTR cows. In contrast, γ-glutamyl transferase was higher overall (across breed) in PEG than in CTR. The PEG group had higher values throughout the postcalving period compared with CTR. Cows treated with pegbovigrastim had also higher alkaline phosphatase (ALP) activity at 1 and 3 d after calving. The Holstein PEG group had higher ALP activity at 3 d compared with the Holstein CTR and Simmental PEG groups, and higher ALP at 1 d compared with the Simmental CTR group. The PEG group had higher levels of IL-6 at 3 and 28 d but higher IL-1β only at 28 d after calving compared with the CTR group. Overall, Holstein cows were characterized by a greater response in the production of inflammation biomarkers (cytokines, haptoglobin, and ceruloplasmin). In addition, PEG cows had higher values of zinc at 1 and 3 d after calving compared with CTR cows. The response observed in plasma biomarkers for energy metabolism and liver functionality after pegbovigrastim treatment in Simmental and Holstein cows was not different from that in control cows. However, our data shed light on the different metabolic adaptations during the transition period between Simmental and Holstein cows, characterized by different energy, inflammatory, and oxidative pattern responses. For the first time, we have highlighted the effect of pegbovigrastim in maintaining stable cytokine levels during the first month after parturition, reflecting greater regulation of neutrophil recruitment, trafficking, and maturation during the inflammatory response. These results provide evidence of the immunomodulatory action of pegbovigrastim around parturition, when dairy cows are highly immunosuppressed. At the same time, these data demonstrate that increasing release of cytokines after parturition is not linked to exacerbation of a systemic inflammation evaluated based on haptoglobin and ceruloplasmin levels.

Forages dry matter (DM) could vary among batches and in particular when silages are fed. These variations could modify nutrients composition of total mixed ration and affect cows performance. The aim of this study was to evaluate the effect of application of a precision feeding system (PFS) based on a near infra-red scanner, on metabolic conditions and milk yield in lactating dairy cows. The study was performed in 7 farms where PFS was installed on feed mixer to perform a weight-adjustment of DM measured in real time on feeds. A cross-over (14 weeks periods) was applied, PFS was switched on (PF-ON) in three herds and off in the other four (PF-OFF) during 1st period, and vice versa in 2nd period. At the end of two periods, in each herd 7 early and 7 mid lactation cows, for a total of 196 cows, were checked for: blood parameters, milk yield and composition. During the study deviation of DM of target diet (calculated on amount of feed in recipe and applying the DM determined in laboratory) and diets really distributed to cows tended to be lower with PF-ON vs. PF-OFF (0.06 vs 0.12 kg, p = .12). In early lactating cows, lower blood urea (4.63 vs 4.88 mmol/L, p = .115) indicated a better feed protein utilisation in PF-ON vs. PF-OFF. Milk yield and composition were not affected. The use of PFS meliorated the consistency of TMR, which could determine a better efficiency of nutrients utilisation and a reduction of production costs.Highlights Near infra-red (NIR) technology can be advantageously applied at farm level within a precision feeding system for dairy cows. The system allowed a more constant daily supply of nutrients with a reduction of metabolic alterations and a higher efficiency of feed protein utilisation. Utilization of NIR technology at farm level can be economically sustainable.

Our study investigates metabolic changes occurring at dry-off and the contribution of milk yield (MY) in such alterations. Thirteen Holsteins were dried off at 55 days from expected calving day (assumed as 0 days from dry-off, DFD) and divided in two groups according to their average daily MY in the last week of lactation, assuming a cut-off of 15 kg·d−1: low MY (7 cows) and high MY (6 cows). From −7 to 34 DFD dry matter intake (DMI) and rumination time were measured. Blood samples were collected at −7, 2, 7, 27 and 34 DFD to assess an haematological and metabolic profile and at −7, 7 and 34 DFD to test functions of circulating white blood cell (WBC) through ex vivo challenges. Data were included in a mixed model for repeated measures assuming MY at dry-off, time and their interaction as fixed effects. After dry-off, DMI was reduced and rumination time was increased in all the animals. High MY cows had greater DMI and rumination time than low MY cows. In blood, WBC counts decreased at 7 DFD and increased the production of pro-inflammatory cytokines at 7 and 34 DFD. Plasmatic concentrations of liver enzymes indicators, positive acute phase proteins (APPs); and nitrogen species increased after dry-off. Conversely, negative APPs and antioxidant species decreased. Those alterations were more marked in high MY animals. This study suggests that dry-off decreased liver function, triggered a systemic inflammation and depleted antioxidant systems, especially in the group of cows with high MY at dry-off.HighlightsInflammation, liver dysfunctions and altered redox balance has been detected after dry-off in all the animals.Cows with highest milk yield before halting of milk removal faced the most severe metabolic challenges.Such founding indicates the management of dry-off as a key point for dairy cows health. Inflammation, liver dysfunctions and altered redox balance has been detected after dry-off in all the animals. Cows with highest milk yield before halting of milk removal faced the most severe metabolic challenges. Such founding indicates the management of dry-off as a key point for dairy cows health.

The main objective of this experiment was to study the γ-glutamyl transferase (GGT) activity in milk during lactation and its relationship with metabolic status of dairy cows, milk yield, milk composition, and cheesemaking properties. The study was performed in a tied stall barn and involved 20 lactations from 12 healthy multiparous Italian Friesian dairy cows. During lactation starting at d 10, milk samples were collected weekly and analyzed for composition, somatic cells count, titratable acidity, and milk coagulation properties. The GGT activity was measured in defatted samples. Blood samples were collected weekly to assess biochemical indicators related to energy, protein, and mineral metabolism, markers of inflammation and some enzyme activities. The lactations of each cow were retrospectively categorized into 2 groups according to their milk GGT activity value through lactation. A median value of GGT activity in the milk of all lactations was calculated (3,045 U/L), and 10 lactations with lower GGT activity were classified as low while 10 lactations with greater GGT activity were classified as high. The average value of milk GGT activity during lactation was 3,863 and 3,024 U/L for high and low, respectively. The GGT activity decreased in early lactation and reached minimum values in the second month (3,289 and 2,355 U/L for high and low, respectively). Thereafter GGT activity increased progressively, reaching values in late lactation of 4,511 and 3,540 U/L in high and low, respectively. On average, milk yield was 40.81 and 42.76 kg/d in high and low, respectively, and a negative partial correlation with milk GGT activity was observed. A greater milk protein concentration was observed in high (3.39%) compared with low (3.18%), and a positive partial correlation with milk GGT activity was observed. Greater titratable acidity in high than that in low (3.75 vs. 3.45 degrees Soxhlet-Henkel/50 mL, respectively) was also observed. Plasma glucose was greater in cows of high than in low group, while plasma urea was lower in the high than in the low group. No relationship between plasma GGT and milk GGT activity was observed. Our results show an important effect of lactation stage on milk GGT activity. The individual effect observed from consecutive lactations and the relationship between milk GGT activity and milk protein concentration in healthy cows could open prospects for GGT as a future tool in improving milk protein content.

Acute acidosis was induced in sheep, and gastrointestinal permeability was assessed by using lactulose as a permeability marker. Metabolism was evaluated by monitoring blood metabolites. Four rams (72.5 ± 4.6 kg BW) were used in a 2 × 2 changeover design experiment. The experimental period lasted 96 h from -24 to 72 h. After 24 h of fasting (from -24 to 0 h) for both controls and acidosis-induced rams (ACID), 0.5 kg of wheat flour was orally dosed at 0 and 12 h of the experimental period to ACID, while the basal diet (grass hay, ad libitum) was restored to control. At 24 h, a lactulose solution (30 g of lactulose in 200 mL of water) was orally administered. Blood samples were collected at -24, 0, 24, 48, and 72 h of the experimental periods for the analysis of metabolic profiles and during the 10 h after lactulose dosage to monitor lactulose changes in blood. In addition, rumen and fecal samples were collected at 24 h of the experimental period. The acidotic challenge markedly reduced (P < 0.01) rumen pH and VFA but increased rumen d- and l-lactic acid (P < 0.01). Concurrently, a decrease of fecal pH and VFA occurred in ACID (P < 0.01), together with an abrupt increase (P < 0.01) of lactate and fecal alkaline phosphatase. Blood lactulose was significantly increased in ACID peaking 2 h after lactulose dosage. Blood glucose, β-hydroxybutyrate, Ca, K, Mg, and alkaline phosphatase showed a significant reduction (P < 0.05) at 24 h, whereas urea and NEFA declined (P < 0.05) from 48 to 72 h. A strong inflammatory acute phase response with oxidative stress in ACID group was observed from 24 to 72 h; higher values of haptoglobin (P < 0.01) were measured from 24 to 72 h and of ceruloplasmin from 48 (P < 0.05) to 72 h (P < 0.01). Among the negative acute phase reactants, plasma albumin, cholesterol, paraoxonase, and Zn concentration also decreased (P < 0.05) in ACID at different time points between 24 and 72 h after acidotic challenge start. A rise (P < 0.05) of reactive oxygen metabolites and a drop of vitamin E (P < 0.01) between 24 and 72 h were indicative of oxidative stress in ACID. The perturbation of these blood metabolites suggests that acute acidosis was effectively induced by our model. The increase of lactulose in blood in ACID indicates that gastrointestinal permeability for the marker increased and the large increment after 2 h from dosage suggests that most of the passage occurred through the rumen or abomasal walls.

The aim of the study was to assess the small intestine permeability by using lactulose as a sugar probe and blood metabolites in sheep after a challenge with repeated indomethacin injections. According to a changeover design, 7 adult sheep (4 males and 3 females) were subjected to 4 intramuscular injections (every 12 h) of saline [control (CRT); 7 animals] or indomethacin (INDO; 7 animals). Two hours after the last injection, 30 g of lactulose were administered orally to both CTR and INDO. Blood samples were collected daily for the analysis of the metabolic profile and 5 samples were collected at 2-h intervals following lactulose ingestion to monitor changes in blood levels of lactulose as an index of intestinal permeability. The INDO challenge induced clinical symptoms such as lack of appetite, dullness, weakness, depression, and diarrhea with traces of blood in the feces. In INDO group, haptoglobin and ceruloplasmin increased (P < 0.01) after INDO challenge whereas a decrease (P < 0.05) of negative acute phase reactants (e.g., cholesterol, albumin, and paraoxonase) was observed. Reactive oxygen metabolites increased (P < 0.01) from 60 to 204 h after the INDO challenge start, with a decrease of vitamin E concentration from 12 (P < 0.01) to 132 h (P < 0.05). Blood lactulose concentrations were increased (P < 0.05) in INDO animals and the highest mean values (17.67 µg/mL in INDO vs. 0.17 µg/mL in CRT; P < 0.01) were observed 6 h after oral dosage of lactulose. These changes indicate that the INDO challenge led to severe inflammatory responses with oxidative stress by enhancing small intestinal permeability in sheep that allowed lactulose to enter in blood. The results of this experiment demonstrate that lactulose can be used as a probe to assess gastrointestinal permeability in adult ruminants to test the consequences of stressing conditions on animal welfare. For this purpose, the most suitable time for blood sampling is between 2 and 8 h after the oral dosage of lactulose.

This study investigated the effects of the administration of long chain omega-3 fatty acids (ω-3 FA) and acetylsalicylic acid (ASA) on inflammation, performance, and fertility in periparturient dairy cows. Five weeks before calving, 26 multiparous dairy cows were randomly assigned to 1 of 3 treatments: ω-3 FA (n = 9; OME), ω-3 FA and ASA (n = 9; OMAS), or palm oil (n = 8; CTR). During the last 3 wk of pregnancy, OME and OMAS groups received daily 12.0 g of fish-derived ω-3 FA, whereas CTR cows received only SFA. In addition, OMAS cows received daily 6.0 mg ASA/kg BW starting at 7 d before calving. Only a few cows had health problems after calving, but those in OMAS were most affected (n = 3 vs. 1 in CTR). Inflammatory status around calving did not improve in OME cows, as confirmed by the patterns of concentration of acute-phase proteins (APP), which were similar to CTR. Compared with CTR and OME, the increase of the positive APP and the decrease of the negative APP (e.g., albumin; P < 0.01) observed in OMAS cows suggested a severe inflammatory status after calving. Compared with OMAS, postcalving energy metabolism was better in OME cows as shown by a lower degree of lipomobilization (smaller BCS drop, greater glucose) and milder ketogenesis (less β-hydroxybutyrate; P < 0.01). Cows in CTR had optimal fertility indices, whereas OMAS was the worst group. The severe inflammation and the more negative energy balance likely contributed to the poor fertility parameters in those cows. It is known that ASA exerts an inhibitory effect on cyclooxygenases, causing a possible decrease in the synthesis of PGF2α. A decreased concentration of PGF2α is connected with alterations in the physiologic processes related to labor and to uterine motility. Cows in OMAS had a longer pregnancy (P < 0.10 vs.OME) and a greater frequency of retained placenta, which may be attributed to decreased synthesis of PGF2α. The administration of ω-3 FA alone did not delay calving or the expulsion of fetal membranes. In conclusion, long-chain ω-3 FA improved the physiological status of cows, partly through better energy balance. The administration of ASA before calving (even at a low dose) in combination with ω-3 FA did not exert any synergistic positive effect on inflammation and performance.

The main objective of this experiment was to study the γ-glutamyl transferase (GGT) activity in milk during lactation and its relationship with metabolic status of dairy cows, milk yield, milk composition, and cheesemaking properties. The study was performed in a tied stall barn and involved 20 lactations from 12 healthy multiparous Italian Friesian dairy cows. During lactation starting at d 10, milk samples were collected weekly and analyzed for composition, somatic cells count, titratable acidity, and milk coagulation properties. The GGT activity was measured in defatted samples. Blood samples were collected weekly to assess biochemical indicators related to energy, protein, and mineral metabolism, markers of inflammation and some enzyme activities. The lactations of each cow were retrospectively categorized into 2 groups according to their milk GGT activity value through lactation. A median value of GGT activity in the milk of all lactations was calculated (3,045 U/L), and 10 lactations with lower GGT activity were classified as low while 10 lactations with greater GGT activity were classified as high. The average value of milk GGT activity during lactation was 3,863 and 3,024 U/L for high and low, respectively. The GGT activity decreased in early lactation and reached minimum values in the second month (3,289 and 2,355 U/L for high and low, respectively). Thereafter GGT activity increased progressively, reaching values in late lactation of 4,511 and 3,540 U/L in high and low, respectively. On average, milk yield was 40.81 and 42.76 kg/d in high and low, respectively, and a negative partial correlation with milk GGT activity was observed. A greater milk protein concentration was observed in high (3.39%) compared with low (3.18%), and a positive partial correlation with milk GGT activity was observed. Greater titratable acidity in high than that in low (3.75 vs. 3.45 degrees Soxhlet-Henkel/50 mL, respectively) was also observed. Plasma glucose was greater in cows of high than in low group, while plasma urea was lower in the high than in the low group. No relationship between plasma GGT and milk GGT activity was observed. Our results show an important effect of lactation stage on milk GGT activity. The individual effect observed from consecutive lactations and the relationship between milk GGT activity and milk protein concentration in healthy cows could open prospects for GGT as a future tool in improving milk protein content.

The liver functionality index (LFI) measures the changes of albumin, cholesterol, and bilirubin concentrations between 3 and 28 d postpartum. This composite index, based on variables with direct relevance to liver-specific plasma protein synthesis (albumin), hepatic/intestinal lipoprotein synthesis (cholesterol), and clearance of breakdown products of heme catabolism (bilirubin), provides a tool for evaluating manifestations of hepatic disease. Both energy and protein metabolism are likely to be affected by various physiological challenges in this period but have not been tested systematically. The present study was conducted to profile AA in cows with high or low LFI during the peripartal period and relate this to production outcomes. Eighteen multiparous cows were used from -21 through 28 d around parturition and divided retrospectively into the high or low LFI group. Blood samples were obtained on -21, -14, -7, 1, 3, 7, 10, 14, 17, 21, and 28 d relative to calving, and biomarkers and AA in plasma were measured. Grouping based on LFI resulted in 8 cows with high LFI (HLFI) and 10 cows with low LFI (LLFI). Although the temporal response in dry matter intake (DMI, 16.3 kg/d) and body condition score (2.56) did not differ, cows with high compared with low LFI had greater overall milk production (37.9 vs. 32.9 kg/d) although energy-corrected milk yield did not differ (42.6 vs. 38.7 kg/d). As expected, cows grouped as LLFI had lower cholesterol and albumin but greater bilirubin after calving compared with HLFI animals. Despite similar temporal responses in DMI between groups, concentrations of total AA were greater in HLFI, particularly after calving. Although concentrations of total essential AA (EAA) and branched-chain AA did not differ with LFI status, cows in HLFI had greater concentrations of Thr and Ile postpartum. Nearly all plasma AA concentrations followed the general trend of a nadir at 1d after calving followed by a gradual increase to prepartal levels before 28 d. Glycine was the only AA exhibiting a gradual increase in concentration through the transition, with a maximum at 7d postpartum followed by a gradual decrease. We detected no effect of LFI status on plasma Lys, which decreased markedly from -21d to calving, followed by an increase to prepartal values by d7. In contrast, concentrations of Met and His decreased markedly between -21 and 10d and did not reach prepartal values by 28 d. The marked decrease in Gln concentration after calving regardless of LFI might compromise immune function during this period. Overall, the results indicate the existence of an association among inflammation, liver function postpartum, and AA plasma concentrations, irrespective of temporal differences in DMI. Cows with better indices of liver function produced more milk and maintained greater concentrations of total AA and some EAA such as Thr and Ile. Whether these AA played a direct role in the greater milk production remains to be determined.

The aim of this study was to investigate the metabolic and biochemical changes in plasma that occur in the reproductive rabbit doe close to the parturition, as well as if the number of offspring affects the metabolism and the health status of the doe. At −3, 4 and 12 days from parturition (–D3, D4, and D12, respectively) nine rabbit does at their third parity from a commercial hybrid line (HYPLUS PS 19) selected for high prolificacy were weighted and blood was collected for a wide inflammometabolic profile. According to the number of offspring the does were retrospectively divided in two groups: high litter size group (HI; n=5) and low litter size group (LO; n=4). BW was higher (P

The intensive breeding is often considered a risk of low welfare in dairy cows. Namely, the high yield has been suggested to be per se a cause of well-being reduction. Conversely, we have in many farms demonstrated that high milk yielding cows are not necessarily in a bad welfare condition, while many environmental and management problems can cause a distress situation and a reduced milk yield. To confirm these results, in an average yielding dairy farm affected by several problems, the welfare was assessed according to an Integrated Diagnostic System which considers health status, milk yield and quality, feeding strategy, blood profiles etc. The same check-up has been repeated a year later, after some attempts to correct main mistakes previously observed: dry and lactating cow diets, n° of cubicles, hygiene conditions, preparation and milking procedures etc. In one year only part of the mistakes have been fully corrected; nevertheless, the animal response was definitively improved suggesting a better welfare situation: improvement of teat and body condition (BCS) scores and reduction of open days, of legs and feet lesions and of somatic cell count (SCC : 283 vs . 456 cells/μl) as well as an increase of milk yield (25.2 vs . 20.1 kg/d). Results confirmed that better breeding techniques can optimise the animal welfare and optimise milk yield in the intensive systems.

The variations of basal value (before morning feeding at 3-4 days interval) and daily pattern (on 4and 18day of treat- ment with 8 blood collections within 24h) of hormones and metabolites were studied in four dairy cows; 2 in early and 2 in late lactation, which were alternatively injected daily for a period of 21 days with 26.3 mg rbST or saline. The rbST injection significantly increased the basal and daily levels of GH, IGF-I in both stages of lactation. Daily levels of NEFA were significantly increased by rbST in both stages of lactation and their variations, due to the effect of meals, were coun- teracted by the rbST; the higher level of NEFA allowed a greater sparing of glucose, the blood level of which resulted higher (P blood urea level (P ticular the high availability of glucose, determined a significantly higher blood level of insulin and T3, and lower level of glucagon. Despite the similar GH, IGF-I and NEFA increases observed in the cows treated in early and late lactation, other metabolic and endocrine consequences resulted more evident in late lactation. Furthermore, some of these variations were affected by the forage meals. It can be concluded, therefore, that the changes occurring in the blood subsequent to a rbST treatment are not equal to those which occur at the start of lactation; moreover, they are affected by the daily feeding pattern and perhaps by the stage of lactation.&nbsp

Milk characteristics are affected by heat stress, but very little information is available on changes of milk protein fractions and their relationship with cheesemaking properties of milk. The main objective of the study was to evaluate the effect of hot season on milk protein fractions and cheesemaking properties of milk for Grana Padano cheese production. The study was carried out in a dairy farm with a cheese factory for transforming the milk to Grana Padano cheese. The study was carried out from June 2012 to May 2013. Temperature and relative humidity of the inside barn were recorded daily during the study period using 8 electronic data loggers programmed to record every 30 min. Constant managerial conditions were maintained during the experimental periods. During the experimental period, feed and diet characteristics, milk yield, and milk characteristics were recorded in summer (from June 29 to July 27, 2012), winter (from January 25 to March 8, 2013), and spring (from May 17 to May 31, 2013). Milk yield was recorded and individual milk samples were taken from 25 cows selected in each season during the p.m. milking. Content of fat, proteins, caseins (CN), lactose and somatic cell count (SCC), titratable acidity, and milk rennet coagulation properties were determined on fresh samples. Milk protein fraction concentrations were determined by the sodium dodecyl sulfate-PAGE. Data were tested for nonnormality by the Shapiro-Wilk test. In case of nonnormality, parameters were normalized by log or exponential transformation. The data were analyzed with repeated measures ANOVA using a mixed model procedure. For all the main milk components (fat, protein, total solids, and solids-not-fat), the lowest values were observed in the summer and the greatest values were observed in the winter. Casein fractions, with the exception of γ-CN, showed the lowest values in the summer and the greatest values in the winter. The content of IgG and serum albumin was greater in summer than in the winter and spring. A mild effect of season was observed for milk SCC, with greater values in summer than in the winter and spring. A worsening of milk coagulation properties was observed in summer season. The alteration of cheesemaking properties during hot season seems strictly linked with changes of milk protein fractions mainly with the decrease of αS-CN and β-CN and the increase of undefined proteins.

Acute acidosis was induced in sheep, and gastrointestinal permeability was assessed by using lactulose as a permeability marker. Metabolism was evaluated by monitoring blood metabolites. Four rams (72.5 ± 4.6 kg BW) were used in a 2 × 2 changeover design experiment. The experimental period lasted 96 h from -24 to 72 h. After 24 h of fasting (from -24 to 0 h) for both controls and acidosis-induced rams (ACID), 0.5 kg of wheat flour was orally dosed at 0 and 12 h of the experimental period to ACID, while the basal diet (grass hay, ad libitum) was restored to control. At 24 h, a lactulose solution (30 g of lactulose in 200 mL of water) was orally administered. Blood samples were collected at -24, 0, 24, 48, and 72 h of the experimental periods for the analysis of metabolic profiles and during the 10 h after lactulose dosage to monitor lactulose changes in blood. In addition, rumen and fecal samples were collected at 24 h of the experimental period. The acidotic challenge markedly reduced (P0.01) rumen pH and VFA but increased rumen d- and l-lactic acid (P0.01). Concurrently, a decrease of fecal pH and VFA occurred in ACID (P0.01), together with an abrupt increase (P0.01) of lactate and fecal alkaline phosphatase. Blood lactulose was significantly increased in ACID peaking 2 h after lactulose dosage. Blood glucose, β-hydroxybutyrate, Ca, K, Mg, and alkaline phosphatase showed a significant reduction (P0.05) at 24 h, whereas urea and NEFA declined (P0.05) from 48 to 72 h. A strong inflammatory acute phase response with oxidative stress in ACID group was observed from 24 to 72 h; higher values of haptoglobin (P0.01) were measured from 24 to 72 h and of ceruloplasmin from 48 (P0.05) to 72 h (P0.01). Among the negative acute phase reactants, plasma albumin, cholesterol, paraoxonase, and Zn concentration also decreased (P0.05) in ACID at different time points between 24 and 72 h after acidotic challenge start. A rise (P0.05) of reactive oxygen metabolites and a drop of vitamin E (P0.01) between 24 and 72 h were indicative of oxidative stress in ACID. The perturbation of these blood metabolites suggests that acute acidosis was effectively induced by our model. The increase of lactulose in blood in ACID indicates that gastrointestinal permeability for the marker increased and the large increment after 2 h from dosage suggests that most of the passage occurred through the rumen or abomasal walls.

Estimation of individual intakes in dairy cows would be beneficial to select animals according to efficiency of milk production. The n-alkanes technique has been used to estimate intake by dairy cows in free stall barns, limiting faecal samples to one or two per day, but diurnal variation in the ratio of dosed to natural alkanes in faeces represents a source of error. We aimed to adapt this technique to estimate feed intake on a large number of lactating dairy cows housed on commercial dairy farms. Using a change-over design, six lactating cows fed a TMR diet were given a dose of 0.5 g/day of C32 n-alkane administered once a day as a drench (DRE) or top fed (TP). Feed offered and refused were weighed daily. After the lead-in phases, faeces were collected at 0700 hours, 1400 hours and 1900 hours on the last 5 days of each dosing period. Dry matter intake (DMI) was estimated from C31, C33 and C32 concentrations in feeds and in faeces for each dosing system and sampling time. DMI estimated from C31 : C32 ratio was better correlated with measured individual DMI than estimates from C33 : C32 ratio. For DRE, the best correlation was for sampling at 1400 hours (R2 = 0.96, P < 0.001), but estimated DMI for the 1400 hours sampling was much higher than the actual DMI. For TP, the best correlation was for sampling at 0700 hours (R2 = 0.83, P < 0.001). Feeding C32 n-alkane and collecting faeces once a day at the same time (0700 hours) represents a valuable protocol to measure individual intake on a large number of animals.

Diet composition defines the amount and type of nutrients absorbed by dairy cows. Endocrine-metabolic interactions can influence these parameters, and so nutrient availability for the mammary gland can significantly vary and affect milk yield and its composition. Six dairy cows in early and then late lactation received, for 28 d in a changeover design, 2 diets designed to provide, within the same stage of lactation, similar amounts of rumen fermentable material but either high starch plus sugar (HS) content or low starch plus sugar content (LS). All diets had similar dietary crude protein and calculated supply of essential amino acids. Dry matter intake within each stage of lactation was similar between groups. Milk yield was similar between groups in early lactation, whereas a higher milk yield was observed in late lactation when feeding HS. At the metabolic level, the main difference observed between the diets in both stages of lactation was lower blood glucose in cows fed LS. The lower glucose availability during consumption of LS caused substantial modifications in the circulating and postprandial pattern of metabolic hormones. Feeding LS versus HS resulted in an increase in the ratio of bovine somatotropin to insulin. This increased mobilization of lipid reserves resulted in higher blood concentrations of nonesterified fatty acids and β-hydroxybutyrate, which contributed to the higher milk fat content in both stages of lactation in the LS group. This greater recourse to body fat stores was confirmed by the greater loss of body weight during early lactation and the slower recovery of body weight in late lactation in cows fed LS. The lower insulin to glucagon ratio observed in cows fed LS in early and late lactation likely caused an increase in hepatic uptake and catabolism of amino acids, as confirmed by the higher blood urea concentrations. Despite the higher catabolism of amino acids in LS in early lactation, similar milk protein output was observed for both diets, suggesting similar availability of amino acids for peripheral tissue and mammary gland. The latter could be the result of sparing of amino acids at the gut level due to starch that escaped from the rumen, and to the balanced amino acid profile of digestible protein. This last aspect appears worthy of further research, with the aim to enhance the efficiency of protein metabolism of dairy cows, reducing environmental nitrogen pollution without affecting milk yield potential.

In their review, Bertoni et al. (2003) have pointed out how in dairy cows milk yield and its characteristics are markedly modified during disease stress (general consequences of any disease). This mainly depends on secretion of cytokines, which determines anorexia, endocrine changes and diversion of some nutrients toward the immune system.

High environmental temperature induces physiological stress in rabbits leading to production losses, also because of their quite poor thermoregulation ability. Some consequences of heat stress affect digestive system functions, with impaired appetite, growth and feed conversion, but also with increased disease incidence. These effects can also reflect on the levels of some blood metabolites. Relatively few experimental works are available on the effects of high environmental temperature on the rabbit metabolic profile reared in commercial farms. The aim of this study was to study, in separate experiments, the effects of “fresh” spring and of “hot” summer temperatures on rabbits performance with particular attention to the behaviour of some metabolic parameters and of some aspects of the functionality of the digestive system.

The study comprised 25 mature horses and incorporated five dietary treatments; a negative control (C: 0.085 ppm of Se in the diet), 3 levels of organic Se supplementation (S2, S3 and S4; 0.2, 0.3 and 0.4 ppm of Se on DM respectively) and one positive control supplemented with Na selenite (N3: 0.3 ppm of Se on DM). Diets were offered for 112 days (supplementary period) after which horses were blood sampled to determine GSH-Px activity. Sampling was repeated at 28 day intervals for the following 112 days (post-supplementary period). Increased GSH-Px activity was observed with ascending concentrations of dietary Se following the supplementary period. GSH-Px activities are still notably higher at the end of the post-supplementary period in S2, S3, S4 and N3 when compared to C, although rates of decline were greatest in those treatments with the highest levels of selenium supplementation. Furthermore, GSH-Px activity was better maintained in those animals that had received organic Se following the withdrawal of Se supplements. Therefore, from a nutritional viewpoint, organic forms of Se are superior to selenite as GSH-Px activity is maintained during periods of Se inadequacy.

With the aim to study the plasma Se content during transition period, 2 groups of 12 dairy cows were monitored the month before and after calving. In stall 1 (S1) cows were tied and individually fed, in stall2 (S2) cows were free and fed TMR. In both stalls cows were supplied with Se as Na-selenite. In S1 3 mg/d of Se were fed mixed with corn silage while, in S2, Se was offered with TMR, in dry period 2 mg/d were added with a mineral-vitamin supplement, in lactation 2.6 mg/d (when DMI was 22.2 kg/d) with the concentrate. Forages, the same for both stalls, and concentrates were sampled for chemical composition and Se determination. Cows were checked for milk yield and its content of somatic cells (SCC), health problems, and bled for Se determination in plasma. Average Se intake was higher in S1, in both dry (4.08 vs 2.76 mg/d) and lactating (5.80 vs 2.11 mg/d) period. Besides the supplementation, differences depended on high Se intake in S1 with the concentrate (increased after calving to 11.5 kg/DM on d 30 and containing 0.24 mg/kg DM of Se). According to the intake, plasma Se content resulted higher in S1 in dry (1.20 vs 0.74 μmol/L) and lactating (1.47 vs 0.62 μmol/L) cows. In close-up plasma Se decreased in both groups, in first days of lactation increased in S1, while decreased in S2 to level indicating a deficient intake (0.50 μmol/L). These results confirm the link between Se intake and its plasma level. Finally, Se plasma content did not seem related to cow health status during transition period.

The effect of exogenous glucose supply by either intrajugular (IJG) or intraduodenal (IDG) infusion at 2.0 mg glucose/kg body weight per min was investigated in four wether sheep (average weight 44 (sd 4) kg) chronically catheterized in the carotid artery and portal veins. Sheep were fed on a dried grass pellet diet hourly using continuous belt feeders. Whole-body glucose irreversible loss (IL) rate, measured with [6-3H[glucose, was increased by 0.5 and 0.8 of exogenous supply for IJG and IDG infusions respectively. Portal glucose utilization, measured by isotope dilution across the portal-drained viscera, was unaffected by additional glucose regardless of the route of glucose supply (P= 0.76 for control ν. glucose infusions) and was a constant proportion of glucose IL (0.28) for all treatments. Portal plasma flow was higher during IDG infusions compared with IJG infusions (1.65 ν. 1.44 litres/min,P=0.055). Circulating total free amino acid concentrations fell during glucose infusions (2146, 1808 and 1683 μmol/l for control, IJG and IDG treatments respectively,P=0.067 for treatment effect) but net portal absorption was not affected by increased glucose supply. Recovery in the portal vein of [1-13C[leucine infused into the duodenum averaged 0.65 and was not affected by increasing glucose supply to the gut tissues. The results show that glucose utilization by gut tissues is responsive to changes in both vascular and luminal glucose supply. The effects of changing gut tissue use of glucose and increased whole body glucose IL on metabolism of nutrients is discussed.