Evidence is presented that bovine somatotrophin (bST) treatment of lactating dairy cows enhances both expression of oviductal insulin-like growth factor II (IGF-II) mRNA and endometrial insulin-like growth factor binding protein 3 (IGFBP-3) mRNA between day 3 and day 7 of the oestrous cycle. mRNA encoding growth hormone (GH) receptor in endometrial tissues increased between day 3 and day 7 of the oestrous cycle. The changes induced by bST treatment may contribute to stimulation of embryo development and increase pregnancy rates in lactating dairy cows. Additive effects of bST and rb interferon tau (rbIFN-tau) to inhibit phorbol ester induction of prostaglandin F2alpha secretion in immortalized bovine endometrial cells indicates that there is interplay between their signal transduction pathways. Non-lactating dairy cows were killed at day 17 after oestrus to evaluate the effects of pregnancy status (cyclic versus pregnant) and bST (bST versus control) treatment on endometrial gene expression. Distinctly different mRNA and protein responses were detected between cyclic and pregnant cows that were related to luteolytic-antiluteolytic drive (that is expression of progesterone receptor, oxytocin receptor, oestradiol receptor alpha and prostaglandin GH synthase 2 (PGHS-2)). The bST-induced changes in PGHS-2 protein (+), oxytocin receptor mRNA (+) and oestrogen receptor alpha protein (+) may potentially affect the mechanisms associated with maintenance of pregnancy. Two experiments were conducted to evaluate whether ovarian follicular suppression induced by biodegradable deslorelin implants would reduce either early or late embryo losses. A 450 microg deslorelin implant used to induce ovulation in a timed insemination programme decreased subsequent follicular development and tended to reduce early embryo losses, whereas a 2.1 mg deslorelin implant failed to reduce late embryonic losses when inserted on day 27 of pregnancy.
Although their action in antagonizing arachidonic acid metabolism is a key antiinflammatory effect of conjugated linoleic acid (CLA) and omega-3 polyunsaturated fatty acids (n-3 PUFA), these molecules have other antiinflammatory effects that might occur upstream of altered eicosanoid production. We examined the effects of two CLA isomers (c9,t11 and t10,c12 isomers), n-3 PUFA (EPA and DHA), and κNF-κB inhibitor (ammonium pyrrolidine dithiocarbamate (PDTC)) on lipopolysaccharide (LPS)-induced secretion of prostaglandins (PGE 2 and PGF 2a ) by bovine endometrial (BEND) cells. LPS increased PGE 2 and PGF 2a concentrations in BEND cell- conditioned media in a concentration- and time-dependent manner. The c9,t11 CLA isomer and EPA decreased prostaglandin response to LPS. Addition of PDTC, alone or in combination with c9,t11 CLA or EPA, inhibited LPS-induced eicosanoid release into the culture medium. Results indicate that the c9,t11 CLA isomer and EPA inhibit the endometrial prostaglandin release in cattle and that these molecules may act through an NF-κB signaling mechanism.
The recognition that omega-3 polyunsaturated fatty acids (n-3 PUFA) possess potent anti-inflammatory properties in human models has prompted studies investigating their efficacy for animal growth and immunity. This study examined the effect of feeding an n-3 PUFA-enriched diet on growth and immune response of weanling piglets. Newly weaned pigs (averaging 27 ± 2 days of age and 8.1 ± 0.7 kg of body weight) were assigned randomly to receive a control (3% vegetable oil, n = 20) or n-3 PUFA-supplemented (3% marine n-3 PUFA, n = 20) diet for 28 day after weaning. Female pigs consuming the n-3 PUFA-enriched diet were lighter at week 4 post-weaning than those fed the vegetable oil supplement. Weanling pigs gained more weight, consumed more feed and had better growth to feed ratios between days 14 and 28 than between days 0 and 14 post-weaning. Plasma insulin-like growth factor I (IGF-I) decreased between days 0 (87.2 ± 17.0 ng/mL) and 14 (68.3 ± 21.1 ng/mL) after weaning and then increased again by day 28 (155.2 ± 20.9 ng/mL). In piglets consuming the vegetable oil-enriched diet, plasma tumor necrosis factor alpha (TNF-α) increased from 37.6 ± 14.5 to 102.9 ± 16.6 pg/mL between days 0 and 14 post-weaning and remained high through day 28 (99.0 ± 17.2 pg/mL). The TNF-α increase detected in the piglets fed vegetable oil was not observed in the piglets fed n-3 PUFA. Results indicate that weaning induces considerable immune stress in piglets and that this stress can be mitigated by dietary supplementation of n-3 PUFA.
Understanding how omega-3 PUFA affect the immune functions of dairy cattle may lead to the development of producer-friendly feeding strategies that will decrease the incidence of diseases and improve reproductive efficiency in dairy cows. This 2-page fact sheet was written by Lokenga Badinga and Cristina Caldari-Torres, and published by the UF Department of Animal Science, July 2011.
The objective of this study was to examine the effect of feeding diets containing fat supplements enriched in either saturated fatty acids (n = 10), Ca salts of trans-octadecenoic fatty acids (tFA, n = 10) or Ca salts of safflower oil fatty acids (SFL, high in linoleic acid, n = 9) on performance, metabolic, and endocrine responses of periparturient Holstein cows. Dietary treatments were initiated at approximately 28 d before calculated calving dates and continued through 49 d postpartum. Blood samples for metabolite and hormone analyses were collected weekly beginning 1 wk before estimated calving date through 7 wk postpartum. Incorporation of tFA or SFL into the peripartum diet had no detectable effects on body weight or body condition score. Cows fed the SFL-enriched diet produced less milk fat and established a positive energy balance sooner after calving than those fed the tFA supplement. Analysis for individual fatty acids resulted in increased concentrations of trans 18:1 fatty acid and conjugated linoleic acid isomers in milk fat from cows supplemented with SFL. Across weeks, the average nonesterified fatty acids concentration in plasma was lower in cows fed the SFL-enriched diet than in those consuming the tFA-supplemented diet. Mean concentrations of plasma glucose, insulin-like growth factor-I, and progesterone were greater in cows fed the SFL-enriched diet compared with those fed the saturated fatty acid-supplemented diet. Feeding fat supplements that can suppress milk fat production during the early postpartum period may help minimize negative energy balance, reduce adipose tissue mobilization, and improve circulating concentrations of insulin-like growth factor-I and progesterone. Whether the SFL supplement would have similar effects without a decrease in milk fat production remains to be determined and warrants further investigation.
Lipopolysaccharide (LPS) modulates innate immunity through alteration of cytokine production by immune cells. The objective of this study was to examine the effect of exogenous conjugated linoleic acid (CLA) and PPAR-γ agonist, rosiglitazone, on LPS-induced tumor necrosis factor α (TNF-α) production by cultured whole blood from prepubertal Holstein heifers (mean age, 5.5 mo). Compared with unstimulated cells, addition of LPS (10 μg/mL) to the culture medium increased (P < 0.03) peripheral blood mononuclear cell proliferation ≤2.5-fold. Coincubation with interferon γ (5 ng/mL) further stimulated (P < 0.01) the lymphoproliferative response to LPS. Lipopolysaccharide increased (P < 0.01) TNF-α concentration in cultured whole blood in a dose- and time-dependent manner. The greatest TNF-α stimulation occurred after 12 h of exposure to 1 μg/mL LPS. Coincubation with trans-10, cis-12 CLA isomer (100 μM) or rosiglitazone (10 μM), a PPAR-γ agonist, decreased (P < 0.01) LPS-induced TNF-α production by 13% and 29%, respectively. Linoleic acid and cis-9, trans-11 CLA isomer had no detectable effects on LPS-induced TNF-α production in cultured bovine blood. The PPAR-γ agonist-induced TNF-α attenuation was reversed when blood was treated with both rosiglitazone and GW9662, a selective PPAR-γ antagonist. Addition of rosiglitazone to the culture medium tended to reduce nuclear factor-κ Bp65 concentration in nuclear and cytosolic extracts isolated from cultured peripheral blood mononuclear cells. Results show that LPS is a potent inducer of TNF-α production in bovine blood cells and that trans-10, cis-12 CLA and PPAR-γ agonists may attenuate the pro-inflammatory response induced by LPS in growing dairy heifers. Additional studies are needed to fully characterize the involvement of nuclear factor-κ B in LPS signaling in bovine blood cells.
Data collected in Florida studies indicate that feeding fat supplements that decrease milk fat test during the early postpartum period may help minimize negative energy balance, reduce body fat mobilization, and improve blood levels of beneficial metabolic and reproductive hormones. This 3-page fact sheet was written by Lokenga Badinga, Richard D. Miles, and Cristina Caldari-Torres, and published by the UF Department of Animal Science, September 2011.
This study was conducted to determine the stage of maturity at which the dry matter (DM) yield and nutritive value of velvet bean (Mucuna pruriens) is optimized. Mucuna was harvested at 77, 110 and 123 days after planting (DAP) from quadruplicate 5m×1m plots within each of 6 blocks. At each DAP, DM yield, chemical composition, botanical composition, in vitro rumen fluid-pepsin DM digestibility (IVDMD) and concentrations of total polyphenols, l-dopa and tannins were determined on the whole plant and botanical fractions. Whole-plant Mucuna DM yield increased (P<0.01) linearly with maturity; proportions of leaves and stems decreased linearly (P<0.01), whereas proportion of pods increased (P<0.01). Concentrations of neutral-detergent fiber (aNDF) in whole plant, leaf, and stem increased (P<0.05), or tended (P<0.10) to increase linearly with maturity, as did the acid-detergent fiber concentration of leaves and stems. Maturity decreased (P<0.05) ether extract concentrations of leaves linearly, and stems quadratically, but increased (P<0.05) whole-plant and pod starch concentrations. Pods contained relatively high concentrations of lysine, histidine, phenylalanine, aspartate, glutamate, leucine, isoleucine, and valine, but low concentrations of methionine and cystine. The essential amino acid index did not vary with maturity. Most minerals in Mucuna are concentrated in the leaves and the whole plant contains sufficient Ca, P, K, Mg, Fe, Cu, Na, Mo, Mn, and Zn for growing sheep, although their bioavailability of these minerals is unknown. Total polyphenol concentration quadratically (P<0.01) increased with maturity in the whole plant, tended to increase (P<0.10) in pods, linearly (P<0.01) decreased in stems and fluctuated in leaves. Maturity quadratically increased l-dopa concentration of the whole plant (P<0.05) and stems (P<0.01), but did not affect those of leaves and pods. Maturity quadratically increased (P<0.05) total tannin concentration in the whole plant, but decreased (P<0.10) that of pods. The l-dopa was concentrated in the seeds and pods of mature (110–123DAP) plants, but tannins were concentrated in leaves and stems. Whole-plant IVDMD was not affected by maturity, but digestible DM yield linearly (P<0.01) increased with increasing DM yield. There was a 2-week harvest window (110–123DAP) during which whole-plant crude protein and IVDMD remained unchanged. Nevertheless, harvesting at 123DAP gave the best combination of biomass yield and nutritive value.
Proteomics holds significant promise as a method for advancing animal science research. The use of this technology in animal science is still in its infancy. The ability of proteomics to simultaneously identify and quantify potentially thousands of proteins is unparalleled. In this review, we will discuss the current state of proteomic technology and cover basic principles of its experimental design. In addition, challenges and limitations of proteomics will be considered, stressing those that are unique to animal sciences. The current proteomic research in animal sciences will be discussed and the potential uses for this technology will be highlighted.
Long chain fatty acids (LCFA), primarily in the form of phospholipids, make up a significant component of the cell membrane structure in animals. These fatty acids can affect membrane fluidity and can serve as signaling molecules and as precursors for the synthesis of eicosanoids, just to name a few roles. In fact, the fatty acids have been called “gatekeepers” of cell regulation (Yaqoob, 2003). In addition, cells dedicated to fight and prevent health problems in animals also contain LCFA in their cell membranes. These LCFA within cells are very dynamic, with the fatty acid profile of these cells open to modification by the fatty acid profile of the diet of the animal. Therefore there is strong interest in conducting human and animal research to determine how dietary fatty acids can influence the immune system. Most of this work has been done in nonruminant species, with little focus on ruminant animals. This paper will give a very brief overview of the effects of the essential fatty acids, the ω-6 (linoleic) and ω-3 (linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid) fatty acids, on the cells and compounds involved in immune preservation primarily of bovine.
The study objective was to evaluate if dietary supplemental polyunsaturated fatty acids, enriched in omega-6 or omega-3 fatty acids, can regulate and improve the immunosuppressive state that is typical of periparturient Holsteins heifers (n=16) and cows (n=29). Treatments were: 1) Control (CO, no fat supplement), 2) Ca salts of fatty acids made from safflower oil (Omega-6, 63% C18:2), and 3) Ca salts of fatty acids made from palm oil and fish oil (Omega-3, 11% eicosapentaenoic acid plus docosahexaenoic acid, StrataGTM). Supplemental fats (Virtus Nutrition, Corcoran, CA) were fed at 1.5% of dietary DM during pre and postpartum periods. Blood samples were taken thrice weekly for 7 wk for determination of acute phase proteins. Phagocytotic and oxidative burst activities of neutrophils were measured using flow cytometry in whole blood samples taken at -18, 0, 7, and 40 DIM. Multiparous cows fed Omega-6 had greater concentrations of fibrinogen (259 vs 206 mg/ dl) compared to Omega-3-fed cows, but values were not different for primiparous cows (226 vs. 254 mg/dl; treatment by parity interaction P<0.05). Heifers fed omega-3 had reduced concentrations of ceruloplasmin compared to omega-6-fed heifers (10.5 vs. 11.9 mg/dl) but values were not different for cows (11.4 vs. 11.1 mg/dl; treatment by parity interaction; P<0.05). Multiparous cows fed fat supplements had greater (59.8 μg/ml) concentrations of acid soluble protein in plasma during the first 3 wk postpartum compared to CO cows (42.9 μg/ml), but this was reversed for primiparous cows (51.7 vs. 45.0 mg/dl; treatment by parity by DIM interaction; P=0.06). Concentrations of WBC (8796 vs 11,492 WBC/μl; P=0.06) and neutrophils (2463 vs 3495 per μl; P<0.01) were lower for omega-3 fed cows compared to cows fed CO or omega-6. Based on median fluorescence intensity, the average neutrophil from omega-3-fed cows phagocytised less E. Coli than those from CO or omega-6-fed cows. Omega-3 attenuated immune responses compared to Omega-6-fed animals.
This study investigated the effect of modifying the n-6:n-3 fatty acid ratio (FAR) of diets using linseed, soybean, and cottonseed oils on apparent digestibility, ruminal fermentation characteristics, growth performance, key circulating hormones, and the fatty acid profile of ruminal digesta, liver, and fore-shank muscle of growing lambs fed a high concentrate diet. Forty individually housed Katadhin Dorper lambs (average of 20.0 kg of BW) were fed Bermudagrass hay in ad libitum amounts and concentrates at 3.7% of BW daily. The concentrate contained 68.9% corn, 23.8% soybean meal, 3.3% limestone, and 4.0% oil supplements (DM basis). The treatments consisted of dietary n-6:n-3 FAR of 2.3:1, 8.8:1, 12.8:1, and 15.6:1. After feeding for 35 d in metabolism crates, lambs were slaughtered 15 h after feeding, and samples of ruminal digesta, blood, liver, and foreshank tissue were collected. Increasing dietary n-6:n-3 FAR did not affect the intake of DM nor the apparent digestibility of DM, ether extract, NDF, or ADF, but did increase apparent digestibility of CP (linear, P < 0.05). Concentrations of ruminal butyrate increased linearly (P < 0.05) with increasing dietary n-6:n-3 FAR, whereas the valerate concentration decreased linearly (P < 0.001). Concentrations of plasma insulin and IGF-I were not affected by dietary n-6:n-3 FAR. Concentrations of C18:3n-3 increased linearly (P < 0.001), whereas that of C18:2n-6 decreased linearly (P < 0.001) in ruminal digesta with decreasing dietary n-6:n-3 FAR. Concentrations of transisomers of fatty acids in ruminal digesta did not change. Proportions of C18:0 in liver and foreshank muscle were unchanged by diet. The proportion of trans11 C18:1 and cis-9 trans11 CLA decreased (P < 0.05) in liver but increased (P < 0.05) in foreshank muscle as dietary n-6:n-3 FAR decreased. Proportions of all measured n-3 fatty acids were greater in liver when diets contained more C18:3n-3 from linseed oil. By decreasing the dietary n-6:n-3 FAR, the proportions of n-6 fatty acids in foreshank muscle decreased dramatically; specifically, C18:2n-6 decreased linearly (P < 0.001) from 28.0 to 16.5% and C20:4n-6 decreased linearly (P < 0.001) from 14.7 to 8.6%. Although feeding a diet that contained more n-3 fatty acids increased the n-3 fatty acid concentration of muscle, the ratio of PUFA to SFA was decreased.
After parturition, immune functions such as lymphocyte response to mitogens and production of antibodies are depressed in dairy cows. Dietary regimens that improve the immune function of dairy cows after calving may improve uterine health and lead to earlier breeding after parturition. The objective of this study was to examine the effect of feeding a calcium salt of trans isomers of fatty acids (tFA) to periparturient Holstein cows on plasma biomarkers of inflammation. Dietary treatments were initiated approximately 28 d before expected calving date and continued through d 21 postpartum. Prepartum and postpartum diets were formulated to be isolipidic, containing 1.5% saturated fats (n = 15) or 1.8% tFA ( n = 15). Multiparous cows were heavier at calving (+32%) and produced more milk (+17%) than primiparous cows. Periparturient tFA supplementation increased plasma PGF(2 alpha) metabolite concentration in multiparous cows, but not in primiparous cows. Concentrations of prostaglandin E-2, tumor necrosis factor-alpha, and interleukin-4 in plasma did not differ between diets and parities. Results raise the possibility that peripartum tFA supplementation may affect uterine health and reproductive efficiency of early lactation dairy cows through alteration of peripheral PGF(2 alpha) concentration.
The objective of this study was to determine the effect of ghrelin on dry matter intake and energy metabolites in ewes during the last 10d of gestation. Ewes were randomly assigned to either a treatment (n=6) or a control group (n=6). One hour after feeding (08:00 and 16:00), ewes in the treated group were given ovine ghrelin (3μg/kg, i.m.) and the control group received an equivalent volume of saline. Treatments were continued until lambing. Daily blood samples were taken starting at assignment. The principal findings were that: (1) ewes treated with ghrelin had a higher dry matter intake only on the first day of treatment; (2) treated ewes had lower serum concentrations of non-esterified fatty acids and insulin but higher serum concentrations of growth hormone; (3) serum concentrations of β-hydroxy butyrate and cortisol were not different between treated and non-treated ewes. In conclusion, treatment with ghrelin affected dry matter intake and energy metabolites of pre-partum ewes during the last 10d of pregnancy.