Fatty Acid Metabolism on Pasture- and Feedlot-Finished Cattle

Feeding high-grain diets to finishing beef cattle results in high proportions of saturated fatty acids (SFA) in the beef, which is considered to confer negative impacts on human health. In contrast, pasture-finished cattle produce lower proportion of SFA, greater n-3 and less n-6 polyunsaturated fatty acids (PUFA), and higher conjugated linoleic acids (CLA) compared to high grain-finished beef (Noviandi et al. 2012). Increased n-3 PUFA, especially C18:3 n-3, can reduce the risk of heart disease, hypertension, inflammation, and mammary cancer, and lower cholesterol concentration in blood (De Deckere et al. 1998; Tapiero et al. 2002). Nitrogen fertilisation can increase biomass production and nitrogen (N) concentration of tall fescue (TF; Festuca arundinacea) (Berg and Sims 2000; Teuton et al. 2007), which positively affected beef cattle performance (Berg and Sims 1995). However, the metabolism of fatty acids (FA) in pasture-finished beef steers due to N fertilization on TF has not yet been studied. Therefore, the current study was performed to test a hypothesis that due to its potential impacts on nutrient and energy utilization, N fertilization would affect FA compositions in ruminal fluid, blood serum, and adipose tissue of pasture-finished beef steers. In addition, we were interested in beneficial effects of grazing steers by comparing the FA profiles between pasture- and feedlot-finished beef steers

The influence of oblique-angle forced exercise in surgically destabilized stifle joints is synergistic with bone, but antagonistic with cartilage in an ovine model of osteoarthritis

Large animal models of osteoarthritis are a necessary testing ground for FDA approval of human medicine applications. Sheep models have advantages over other available large animals, but development and progression of osteoarthritis in sheep is exceedingly slow, which handicaps progress in development of potential treatments. We combined oblique angle forced exercise to increase stress on the stifle, with surgical destabilization to hasten the development of osteoarthritis in ewes. Methods for early detection of clinical signs included radiography, urine, and serum biomarker assays and gait analysis and ex vivo we used microcomputed tomography and macroscopic joint analysis. Our model was able to produce clinically detectable signs of osteoarthritis in a relatively short period (14 weeks). Changes in bone were highly correlated between microcomputed tomography and radiographic analysis and changes in cartilage correlated well between urinary glycosaminoglycan levels and serum aggrecanase analyses. Exercise improved the negative effects of destabilization in bone but exacerbated the negative effects of destabilization in cartilage. These observations suggest that we may need to consider treatments for bone and cartilage separately. These results represent an improved large animal model of osteoarthritis with rapid onset of disease and superior detection of bone and soft tissue changes

Cytokine Gene Expression in the Maternal-Fetal Interface in Somatic Cell Nuclear Transfer Pregnancies in Small Ruminants

The present retrospective study investigates pregnancy rates, incidence of pregnancy losses and large offspring syndrome (LOS), and immune-related gene expression of sheep and goat somatic cell nuclear transfer (SCNT) pregnancies. We hypothesized that significantly higher pregnancy losses observed in sheep SCNT pregnancies compared to goats are due to the increased amounts of T-helper 1 cytokines and pro-inflammatory mediators at the maternal-fetal interface. Sheep and goat SCNT pregnancies were generated using the same procedure. Control pregnancies were established by natural breeding. Although SCNT pregnancy rates at 45 days were similar in both species, pregnancy losses between 45 and 60 days and incidence of LOS were significantly increased in sheep compared with goats. At term, the expression of pro-inflammatory genes in sheep SCNT placentas was increased while the one of goat SCNT was similar to the control animals. Among the genes that had altered expression in sheep SCNT placentas are CTLA4, IL2RA, CD28, IFNG, IL6, IL10, TGFB1, TNF, IL1A and CXCL8. MHC-I protein expression was greater in sheep and goat SCNT placentas at term compared with control pregnancies. An unfavorable immune environment is present at the maternal-fetal interface in sheep SCNT pregnancies

Rumen Distension and Contraction Influence Feed Preference by Sheep

Distension of the rumen limits feed intake by livestock. Ruminal dysfunctions due to bloat, which causes distension by accumulation of excessive gas within the rumen, also reduce feeding. We hypothesized that excessive levels of rumen distension cause feed aversions and that preference increases for feeds eaten in association with recovery from bloat. To test these hypotheses, we determined whether 12 commercial crossbred lambs (average initial BW of 43 ± 2 kg) could associate ingestion of specific feeds with the consequences of increased intraruminal pressure and its subsidence. Six of the lambs were fitted with rumen cannulas and offered ground alfalfa for 30 min after a rubber balloon was inserted into the rumen of each animal and distended with air to volumes of 1.8, 2.5, or 4.5 L. Subsequently, balloons were deflated and alfalfa was offered again for a second period of 30 min. Feed intake was not affected when the balloon was not distended (P = 0.45 to 0.93), but distension reduced feed intake (P \u3c 0.001) in direct proportion to the magnitude of distension at all 3 volumes (R2 = 0.70). Relief from distension promoted a compensatory increase in feed intake (P = 0.006). During conditioning to determine if lambs acquired a preference for a feed associated with recovery from distension, fistulated lambs were offered novel feeds: wheat bran (group 1; n = 3) and beet pulp (group 2; n = 3), and the balloon was distended for 30 min. Feeds were then switched and the balloons were deflated (recovery). Control lambs (n = 6) received the same feeding protocol without the balloons. Lambs formed strong aversions to feeds associated with distension and preferred feeds associated with recovery (P = 0.001 to P = 0.10). No preferences or avoidances were observed in control lambs conditioned without rumen distension (P = 0.17 to P = 0.87). Thus, rumen distension and recovery from distension induced feed aversions and preferences, respectively, which may be critical in learning avoidance of bloat-inducing plants and preferences for plants and supplements that relieve the incidence of bloat

Urine Volume and Nitrogen Excretion are Altered by Feeding Birdsfoot Trefoil Compared with Alfalfa in Lactating Dairy Cows

Legumes that contain condensed tannins may have lower ruminal protein degradation than alfalfa. The present study investigated the effects of feeding birdsfoot trefoil (Lotus corniculatus L.) hay on lactational performance and N utilization and excretion. Eight multiparous Holstein cows in midlactation (150 ± 22.3 d-in-milk) were randomly assigned to 2 treatments [alfalfa hay-based total mixed ration (AHT) or birdsfoot trefoil hay-based total mixed ration (BHT)] in a crossover design with 2 experimental periods. Each experimental period lasted 17 d (14 d of adaptation and 3 d of sampling and total collection). Hays comprised approximately 50% of DM in experimental diets. There were no treatment effects on dry matter intake (DMI; 21.4 vs. 20.7 kg/d), milk yield (29.4 vs. 28.1 kg/d), milk fat concentration (3.20% vs. 3.21%), and milk protein concentration (3.20% vs. 3.16%) for AHT and BHT, respectively. In addition, dietary treatments did not affect milk yield/DMI or energy-corrected milk yield/DMI. In contrast, apparent crude protein digestion decreased in cows fed BHT compared with those fed AHT (60.7% vs. 69.1%). Concentration of milk urea-N decreased by feeding BHT compared with AHT (11.9 vs. 13.3 mg/100 mL), whereas total N excretion did not differ between AHT and BHT diets. However, cows fed BHT excreted more N in feces (194 vs. 168 g/d), whereas urinary N excretion was lower compared with cows fed AHT. The shift of N to feces resulted in a decrease in urinary N:fecal N ratio in cows fed BHT relative to those fed AHT. Overall results in the current study suggest that feeding birdsfoot trefoil in dairy diets shifts routes of N from urine to feces compared with feeding alfalfa hay, with little effect on lactational performance. Reduction in urinary N and any impact on environment may be attributed to functional effect of condensed tannins in birdsfoot trefoil hay

Cytokine gene expression in the maternal-fetal interface after somatic cell nuclear transfer pregnancies in small ruminants

The present retrospective study investigated pregnancy rates, the incidence of pregnancy loss and large offspring syndrome (LOS) and immune-related gene expression of sheep and goat somatic cell nuclear transfer (SCNT) pregnancies. We hypothesised that significantly higher pregnancy losses observed in sheep compared with goat SCNT pregnancies are due to the increased amounts of T-helper 1 cytokines and proinflammatory mediators at the maternal-fetal interface. Sheep and goat SCNT pregnancies were generated using the same procedure. Control pregnancies were established by natural breeding. Although SCNT pregnancy rates at 45 days were similar in both species, pregnancy losses between 45 and 60 days of gestation and the incidence of LOS were significantly greater in sheep than in goats. At term, the expression of proinflammatory genes in sheep SCNT placentas was increased, whereas that in goats was similar to that in control animals. Genes with altered expression in sheep SCNT placentas included cytotoxic T-lymphocyte-Associated protein 4 (CTLA4), interleukin 2 receptor alpha (IL2RA), cluster of differentiation 28 (CD28), interferon gamma (IFNG), interleukin 6 (IL6), interleukin 10 (IL10), transforming growth factor beta 1 (TGFB1), tumor necrosis factor alpha (TNF-), interleukin 1 alpha (IL1A) and chemokine (C-X-C motif) ligand 8 (CXCL8). Major histocompatibility complex-I protein expression was greater in sheep and goat SCNT placentas at term than in control pregnancies. An unfavourable immune environment is present at the maternal-fetal interface in sheep SCNT pregnancies