Biology subjects

Boudon, A.

Publications and source records attributed to Boudon, A..

4 recordsLinked to original sources

bioRxiv2025

Nutritional supplementation with vitamin E or plant extracts affects redox and immune response in early lactating dairy cows

In dairy cows, early lactation is a period prone to oxidative stress, inflammation and health problems. Our objective was to investigate the effects of the nutritional supplementation of early lactating cows with plant extracts or vitamin E on physiological and immunological status. Forty-five Holstein cows were divided into three groups: control group (n = 15), vitamin E group (n = 16) (3,000 IU/d for 3 weeks before and 1,000 IU/d after calving), and plant extract group (n = 14) (10 g/d only after calving). Their redox and immune status were monitored during the first 12 weeks of lactation, every four week. In week 12, plasma malondialdehyde levels in plasma were lower in the vitamin E and plant extract groups than in the control group. The vitamin E and plant extract groups had lower ex vivo plasma CCL4, IL6 and IL8 cytokine levels, lower proportions of blood regulatory neutrophils, and less ROS production by blood neutrophils than the control group. In terms of immune response, vitamin E and plant extracts down-regulated the gene expression of FABP3 in the milk mammary epithelial cells of multiparous cows. Therefore, supplementation with either vitamin E or plant extracts could prevent systemic hyper-inflammation and improve the immune response during early lactation.

physiology↗

bioRxiv2025

Nutritional vitamin E or plant extracts affect the immune response and mammary epithelium integrity during intramammary lipopolysaccharide challenge in early lactation

BackgroundEarly lactation is a period at risk for mastitis. Our objective was to investigate the influence of nutritional vitamin E and plant extracts on redox and immune status at the systemic and local mammary levels during an inflammatory challenge in dairy cows. Thirty-six Holstein cows were placed in three groups: a control group (n = 11) unsupplemented; a vitamin E group (n = 13), supplemented with 3000 IU/d for 4 weeks before calving and 1000 IU/d for 4 weeks after calving; and a plant extracts group (n = 14) supplemented with 10 g/d for 4 weeks before and after calving. Lipopolysaccharide (LPS) from Escherichia coli was infused into a one-udder quarter of the cows 5 weeks after calving. Blood and milk samples were collected before and 4, 7, 9, 28, and 76 h after the LPS infusion. ResultsIn the plant extract group, antioxidant gene (NQO1), superoxide dismutase activity 4 hours after the LPS challenge and total antioxidant capacity were increased compared to the control group. In the vitamin E group, expression of the antioxidant gene (SOD3) and glutathione peroxidase activity were more elevated than in the control group. Systemic immunity appeared to be reduced by antioxidant supplementations, with a higher migration of classical neutrophils in the plant extract group and less ROS production of neutrophils in the vitamin E group. However, immune capacities were increased at the local level in classical neutrophils (ROS production and phagocytosis) in both the plant extract and vitamin E groups. Following the LPS infusion, supplementation did not reveal any differences in terms of rectal temperature, milk yield or milk cell counts, but it did have a positive effect on mammary epithelium integrity (lower milk Na+:K+ ratio and higher OCLN gene expression). In addition, the plant extracts stimulated the synthesis of milk constituents, with higher milk protein gene expressions (LALBA, CSN3, CSN1S1) and a tendency towards a higher lactose content in milk. ConclusionThe LPS challenge showed that vitamin E or plant extracts enhanced the local inflammatory response while preserving systemic antioxidant capacities, integrity of the mammary gland and the composition of milk, and thus possibly contributing to preventing mammary infection in early lactating dairy cows.

physiology↗

bioRxiv2025

Oral-stomach sampling to replace rumen-fistulated animals in ruminant nutrition research - a case study

Studies using fistulated ruminants have shed light on digestion and fermentation in the rumen and yielded tools to determine the feed efficiency of diets, limit effluents or anticipate variability in the quality of animal products. However, the ethical acceptability of such studies has been called into question. Our objective was to determine whether oral-stomach sampling (OSS) is an acceptable alternative to sampling through a ruminal cannula in characterizing the variability of rumen fluid composition induced by an acidogenic dietary challenge in dairy cows. During three four-week periods (P1, P2, P3), six rumen-fistulated cows were fed a standard diet based on supplemented corn silage (periods 1 and 3) alternating with a diet enriched with starch (period 2). Rumen juice was collected through cannulas at three locations in the rumen (reticulum, ventral sac or a mix of both) and by OSS, once per week at 0830 h, i.e. before morning feeding, and once every third week of each period at 1330 h, i.e. 4.5 hours after morning feeding. Whatever the sampling method or location, ruminal pH was lower in period 2 compared to periods 1 and 3 at 1330 h (6.21 vs. 5.57 vs. 6.12 in periods 1, 2 and 3). Ruminal pH was higher when obtained by OSS rather than cannulation, whatever the sampling location (on average, +0.44 points at 0830 h and +0.56 points at 1330 h). Mineral composition indicated a presumed dilution by saliva of OSS samples. This was also consistent with lower concentrations of volatile fatty acids. The next steps will be to analyze the associated variations in in vitro rumen fermentation parameters and microbiota composition. ImplicationsThe use of fistulated ruminants to elucidate ruminal physiology is currently controversial in society. In order to minimise, reduce or replace these experimental models, alternatives to ruminal fistula sampling are being evaluated. Here we focus on oral stomach sampling (OSS). We show that OSS can be a satisfactory alternative to cannula sampling in the evaluation of rumen fermentation parameters, especially for the molar proportion of volatile fatty acids, rumen pH, and rumen volatile fatty acid and ammonia concentrations. We also show that OSS must be standardized to avoid salivary contamination affecting the quality of the results.

physiology↗

bioRxiv2019

Effect of calcium intake and dietary cation anion difference in early lactation on bone mobilization dynamics all over lactation in dairy cows

This study aimed to evaluate the consequences of increased bone mobilization in early lactation on the dynamics of the milk Ca content during lactation and bone reconstitution. Fifteen multiparous Holstein cows were distributed among 3 treatments 5 weeks before their expected calving date. Those treatments consisted of the provision of dedicated diets through the first 10 weeks of lactation. During that period, the control treatment (NCa) consisted of a diet providing 100\\% of the Ca requirements, with a dietary cation-anion difference (DCAD) of 200 mEq/kg DM. The treatments LCa (Low Ca) and LCaLD (Low Ca, Low DCAD) consisted of diets providing 70% of the Ca requirements, with a DCAD of 200 and 0 mEq/kg DM for LCa and LCaLD, respectively. After 10 weeks, all cows received the same total mixed ration which was formulated to meet 100\\% of the Ca requirements. LCa and LCaLD tended to decrease the body retention of Ca at 3 weeks of lactation compared with NCa, but did not affect either the dynamics of the blood biomarkers of bone formation and resorption during the lactation or the body retention of Ca at 17 weeks of lactation. Cows almost entirely compensated for the decrease in Ca supply by increasing their apparent digestive absorption of Ca at 3 weeks of lactation, whereas the apparent digestive absorption was unaffected by the treatments at 17 weeks of lactation. Milk production tended to be lower throughout lactation with the LCa and LCaLD compared with the NCa, with a mean difference of 2 kg/d. This study indicated that measuring the dynamics of the milk Ca content during lactation cannot be considered effective for indirectly estimating the dynamics of bone mobilization of cows. The results also showed that limited Ca intake at the beginning of lactation can have deleterious effect on milk production.

physiology↗