Effect of chromium picolinate and chromium propionate on glucose and insulin kinetics of growing barrows and on growth and carcass traits of growing-finishing barrows

Two experiments were conducted to determine the effects of dietary Cr tripicolinate (CrPic) or Cr propionate (CrProp) on growth, carcass traits, plasma metabolites, glucose tolerance, and insulin sensitivity in pigs. In Exp. 1, 36 barrows (12 per treatment; initial and final BW were 20 and 38 kg) were allotted to the following treatments: 1) corn-soybean meal basal diet (control), 2) as 1 + 200 ppb Cr as CrPic, or 3) as 1 + 200 ppb Cr as CrProp. Growth performance data were collected for 28 d, and then 23 pigs (seven, eight, and eight pigs for treatments 1, 2, and 3, respectively) were fitted with jugular catheters and a glucose tolerance test (500 mg glucose/kg BW) and an insulin challenge test (0.1 IU of porcine insulin/kg BW) were conducted. Both CrPic and CrProp decreased (P < 0.05) ADG and ADFI but did not affect gain:feed (P > 0.10). Fasting plasma glucose, total cholesterol, urea N, insulin, and high-density lipoprotein cholesterol:total cholesterol concentrations were not affected (P > 0.10) by either Cr source. Pigs fed CrPic had lower (P < 0.02) fasting plasma NEFA concentrations than control pigs, but plasma NEFA concentrations of pigs fed CrProp were not affected (P > 0.10). During the glucose tolerance test, glucose and insulin kinetics were not affected by treatment (P > 0.10). During the insulin challenge test, glucose clearance was increased (P < 0.01) in pigs fed CrProp but not affected (P > 0.10) in pigs fed CrPic. Glucose half-life was decreased (P < 0.03) in pigs fed CrPic or CrProp, but insulin kinetics were not affected (P > 0.10). In Exp. 2, 48 barrows (four replicates of four pigs per replicate; initial and final BW were 23 and 115 kg) were allotted to the same dietary treatments in a growing-finishing study. Average daily gain, ADFI, and gain:feed were not affected (P > 0.10) by treatments. Carcass length tended (P = 0.10) to be greater in pigs fed CrPic than in pigs fed CrProp, but other carcass measurements were not affected (P > 0.10). Glucose kinetics from the insulin challenge test indicate that both CrPic and CrProp increase insulin sensitivity and that both Cr sources are bioavailable.     

Effects of water and diet acidification with and without antibiotics on weanling pig growth and microbial shedding

Two 5-wk experiments were conducted to determine the effects of water and diet acidification with and without antibiotics on weanling pig growth performance and microbial shedding. In Exp. 1, 204 pigs (19.2 d of age) were used in a 3 x 2 factorial, with 3 dietary treatments fed with or without water acidification (2.58 mL/L of a propionic acid blend; KEM SAN, Kemin Americas, Des Moines, IA). Dietary treatments were: 1) control, 2) control + 55 ppm of carbadox (CB), and 3) dietary acid [DA; control + 0.4% organic acid-based blend (fumaric, lactate, citric, propionic, and benzoic acids; Kemin Americas)] on d 0 to 7 followed by 0.2% inorganic acid-based blend (phosphoric, fumaric, lactic, and citric acids; Kemin Americas) on d 7 to 34. In Exp. 2, 210 pigs (average 18.3 d of age) were fed 1 of 3 dietary treatments: 1) control, 2) control + 55 ppm of CB, and 3) control + 38.6 ppm of tiamulin + 441 ppm of chlortetracycline on d 0 to 7 followed by 110 ppm of chlortetracycline on d 7 to 35 (TC) with or without dietary acidification (same as Exp. 1) in a 3 x 2 factorial arrangement of treatments. For both experiments, the pigs were allotted based on genetics, sex, and initial BW [5.5 kg (Exp. 1) or 5.6 kg (Exp. 2)]. Pigs were housed at 6 or 7 (Exp. 1) and 7 (Exp. 2) pigs/pen. Treatments were fed in 3 phases: d 0 to 7, 7 to 21, and 21 to 35 (34 d, Exp. 1). Fecal grab samples were collected from 3 pigs/pen on d 6, 20, and 33 for measurement of pH and Escherichia coli. During phase 3 and overall in Exp. 1, pigs fed CB had greater (P < 0.001) ADG (overall ADG, 389 vs. 348, and 348 g/d, respectively), ADFI (P < 0.007, 608 vs. 559, and 554 g/d, respectively), and d 34 BW (P < 0.001, 18.8 vs. 17.3, and 17.3 kg, respectively) than pigs fed NC and DA. Phase 3 ADG was improved (P < 0.01) by water acidification across all diets. In Exp. 2, pigs fed CB and TC had greater ADG (P < 0.004; 315 and 303 vs. 270 g/d, respectively), ADFI (P < 0.01), and d 35 BW (P < 0.002; 16.7 and 16.2 vs. 15.1 kg, respectively) than pigs fed NC. There was a tendency (P < 0.08) for an improvement in ADG when DA was added to the NC or TC, but decreased ADG when DA was added to CB.     

Varietal tolerance to Zinc deficiency in wheat and barley grown in chelatorbuffered nutrient solution and its effect on uptake of Cu,Fe, and Mn

Tolerance to zinc (Zn) deficiency was examined for three wheat (Triticum aestivum L.) and three barley (Hordeum vulgare L.) varieties grown in chelator‐buffered nutrient solution. Four indices were chosen to characterize tolerance to Zn deficiency: (1) relative shoot weight at low compared to high Zn supply (“Zn efficiency index”), (2) relative shoot to root ratio at low compared to high Zn supply, (3) total shoot uptake of Zn under deficient conditions, and (4) shoot dry weight under deficient conditions. Barley and wheat exhibited different tolerance to Zn deficiency, with barley being consistently more tolerant than wheat as assessed by all four indices. The tolerance to Zn deficiency in the barley varieties was in the order Thule=Tyra>Kinnan, and that of wheat in the order Bastian=Avle>Vinjett. The less tolerant varieties of both species accumulated more P in the shoots than the more tolerant varieties. For all varieties, the concentrations of Mn, Fe, Cu, and P in shoot tissue were negatively correlated with Zn supply. This antagonism was more pronounced for Mn and P than for Cu and Fe. Accumulation of Cu in barley roots was extremely high under Zn‐deficient conditions, an effect not so clearly indicated in wheat.     

Acetylcholine-synthesizing T cells relay neural signals in a vagus nerve circuit

Neural circuits regulate cytokine production to prevent potentially damaging inflammation. A prototypical vagus nerve circuit, the inflammatory reflex, inhibits tumor necrosis factor-α production in spleen by a mechanism requiring acetylcholine signaling through the α7 nicotinic acetylcholine receptor expressed on cytokine-producing macrophages. Nerve fibers in spleen lack the enzymatic machinery necessary for acetylcholine production; therefore, how does this neural circuit terminate in cholinergic signaling? We identified an acetylcholine-producing, memory phenotype T cell population in mice that is integral to the inflammatory reflex. These acetylcholine-producing T cells are required for inhibition of cytokine production by vagus nerve stimulation. Thus, action potentials originating in the vagus nerve regulate T cells, which in turn produce the neurotransmitter, acetylcholine, required to control innate immune responses.     

Impacts of parasites on marine survival of Atlantic salmon: a meta‐analysis

Parasites can, in theory, have large impacts on the survival of fish populations. One method to evaluate such impacts on anadromous species is to apply manipulative field experiments in which parallel groups of antiparasitically treated and non‐treated fish are simultaneously released and then subsequently recaptured as returning adults. A systematic review and meta‐analysis on all such Norwegian studies on Salmo salar provided a data set for the time period 1996 to 2011 on 118 release groups comprising 657 624 fish released and 3989 recaptured. The overall risk ratio (RR) was estimated to be 1.18 (95% CI: 1.07–1.30). The effect varied strongly between groups, (Higgins I² = 40.1%). Over 70% of this heterogeneity could be explained by the release location, time period and baseline survival. The most important predictor variable was baseline survival. In groups with low recapture in the control group (low baseline survival), the effect of treatment was high (RR = 1.7), while in groups with high recapture in the control group (high baseline survival), there was no effect of treatment (RR ~ 1.00). The most prevalent parasite in the region affected by the drugs administered was Lepeophtheirus salmonis. Hence, the meta‐analysis supports the hypothesis that L. salmonis contributes to the mortality of S. salar during outward migration. However, the effect of treatment was not consistent, but was evidently strongly modulated by other risk factors. The results suggest that the population‐level effects of parasites cannot be estimated independently of other factors affecting the marine survival of S. salar.     

Effect of chromium propionate and metabolizable energy on growth,carcass traits,and pork quality of growing-finishing pigs

An experiment was conducted to evaluate the dietary effects of Cr propionate (CrProp) and metabolizable energy (ME) on growth, carcass traits, and pork quality of growing-finishing pigs. One hundred forty-four Cambrough-22 barrows were allotted to four dietary treatments in a randomized complete block design (six replicates of six pigs per replicate; average initial and final body weight were 27 and 113 kg, respectively). The dietary treatments were: 1) corn-soybean meal basal (B; low ME), 2) B + 200 ppb of Cr (as CrProp), 3) B + 200 kcal ME/kg (4.5% added fat; high ME), or 4) B + 200 kcal ME/kg + 200 ppb of Cr. At trial termination, three pigs per replicate were killed to determine dietary effects on carcass traits and pork quality. Overall average daily gain, average daily feed intake, and gain:feed ratio were not affected (P > 0.10) by diet. During the early growing period, average daily gain was increased in pigs fed the CrProp-low-ME diets, but decreased in pigs fed the CrProp-high ME diets (Cr x ME, P < 0.04). Feed intake was increased (P < 0.05) in pigs fed the high-ME diets during the early growing period. Forty-five min and 24 h pH were not affected (P > 0.10) by diet. The CIE L* tended (P = 0.07) to be increased and shear force tended (P = 0.06) to be decreased in pigs fed high-ME diets. Subjective marbling was increased (P < 0.03) and longissimus muscle percentage moisture and thaw loss were decreased (P < 0.04) in pigs fed CrProp. Chromium propionate had no consistent effect on growth and carcass traits in this experiment; however, CrProp did affect some aspects of pork quality.     

A possible role for Clostridium difficile in the etiology of calf enteritis

Clostridium difficile was investigated as a possible cause of enteritis in calves. The organism and its toxins (TcdA and TcdB), respectively, were found in 25.3% and 22.9% of stool samples from diarrheic calves. Culture positive samples were more likely than culture negative samples to be toxin positive. However, toxin positive stools were more common among nondiarrheic calves, but diarrheic calves were nearly twice as likely to be culture positive. Ribotype 078 was dominant among isolates. Salmonella sp. was isolated from both diarrheic and nondiarrheic calves, but large numbers of E. coli were found more commonly in diarrheic calves than in nondiarrheic animals. Prevalence rates for coronavirus and Cryptosporidium sp. were substantially higher in nondiarrheic calves than in diarrheic, but rates of detection of rotavirus and Giardia sp. were more nearly equal between groups. Lesions in naturally infected calves included superficial mucosal erosion with associated fibrinous exudates. Neutrophils and eosinophils infiltrated lamina propria. Large Gram-positive rods morphologically compatible with C. difficile were abundant in the colonic lumen and the organism was isolated by bacteriologic culture. Toxins were found throughout the colon. Purified toxins A and B (individually and conjointly) caused comparable lesions, as well as fluid accumulation, in ligated intestinal loops. Our findings are in substantial agreement with those of others [Rodriguez-Palacios, A., Stampfli, H.R., Duffield, T., Peregrine, A.S., Trotz-Williams, L.A., Arroyo, L.G., Brazier, J.S., Weese, J.S., 2006. Clostridium difficile PCR ribotypes in calves, Canada. Emerg. Infect. Dis. 12, 1730-1736; Porter, M.C., Reggiardo, C., Bueschel, D.M., Keel, M.K., Songer, J.G., 2002. Association of Clostridium difficile with bovine neonatal diarrhea. Proc. 45th Ann. Mtg. Amer. Assoc. Vet. Lab. Diagn., St. Louis, MO, U.S.A.] and add strength to a working hypothesis that C. difficile infection and the accompanying intoxication can manifest as diarrhea in calves. It seems clear that calves serve as multiplying hosts for this organism.     

Effects of emulsification, fat encapsulation, and pelleting on weanling pig performance and nutrient digestibility

Two experiments were conducted to evaluate the effect of lysolecithin on performance and nutrient digestibility of nursery pigs and to determine the effects of fat encapsulation by spray drying in diets fed in either meal or pelleted form. In Exp. 1, 108 pigs (21 d of age; 5.96 +/- 0.16 kg BW) were allotted to one of four dietary treatments (as-fed basis): 1) control with no added lard, 2) control with 5% added lard, 3) treatment 2 with 0.02% lysolecithin, and 4) treatment 2 with 0.1% lysolecithin in a 35-d experiment. Added lard decreased ADG (P = 0.02) and ADFI (P < 0.06) during d 15 to 35 and overall. Lysolecithin improved ADG linearly (P = 0.04) during d 15 to 35 and overall, but did not affect ADFI or G:F. Addition of lard decreased the digestibility of DM (P = 0.10) and CP (P = 0.05) and increased (P = 0.001) fat digestibility when measured on d 10. Lysolecithin at 0.02%, but not 0.10%, tended to improve the digestibility of fat (P = 0.10). On d 28, digestibilities of DM, fat, CP, P, (P = 0.001), and GE (P = 0.03) were increased with the addition of lard, and lysolecithin supplementation linearly decreased digestibilities of DM (P = 0.003), GE (P = 0.007), CP, and P (P = 0.001). In Exp. 2, 144 pigs (21 d of age, 6.04 +/- 0.16 kg BW) were allotted to one of six treatments in a 3 x 2 factorial randomized complete block design. Factors included 1) level (as-fed basis) and source of fat (control diet with 1% lard; control diet with 5% additional lard; and control diet with 5% additional lard from encapsulated, spray-dried fat) and 2) diet form (pelleted or meal). Addition of lard decreased feed intake during d 0 to 14 (P = 0.04), d 15 to 35 (P = 0.01), and overall (P = 0.008), and improved G:F for d 15 to 35 (P = 0.04) and overall (P = 0.07). Encapsulated, spray-dried lard increased ADG (P = 0.004) and G:F (P = 0.003) during d 15 to 28 compared with the equivalent amount of fat as unprocessed lard. Pelleting increased ADG (P = 0.006) during d 0 to 14, decreased feed intake during d 15 to 35 (P = 0.01), and overall (P = 0.07), and increased G:F during all periods (P < 0.02). Fat digestibility was increased (P = 0.001) with supplementation of lard, and this effect was greater when diets were fed in meal form (interaction, P = 0.004). Pelleting increased the digestibility of DM, OM, and fat (P < 0.002). Results indicate that growth performance may be improved by lysolecithin supplementation to diets with added lard and by encapsulation of lard through spray drying.     

Long-term effects of crop rotation and different fertilization systems on soil fertility and productivity

The effects of crop rotation and fertilization systems on yield and soil fertility parameters have been investigated in a long-term field trial established in southeast Norway in 1953. The results indicate the small differences between crop rotations and different fertilization systems in yield and soil fertility parameters; the decreasing trend in soil organic carbon (SOC) (from 3.8 to 3.7%) and increasing trend of N with time (from 0.32 to 0.36%) and, as a result, the decreasing trend in C/N ratio (from 12 to 10).     

Cooling,Storing and Quality of Raw Milk

Abstract

Full-scale experiments with cooling of raw milk of good initial quality from a herd of 70 dairy cows have been performed under practical farm conditions, with different cooling and storage conditions, including instant cooling in a continuous process versus normal cooling in a batch process. During each milking, the milk was divided equally and successively for different cooling procedures. Quality evaluations (number of bacteria, acidity and oxidation of fat, sensoric quality) indicated that instant cooling/continuous process compared with normal cooling/batch process over 2.5 hours, both to 4°C, resulted in a slightly slower bacterial growth and a slightly slower hydrolysis and oxidation of milk fat. Instant raw milk cooled and stored at 2.5°C maintained a good quality for about one to two days more than when normal cooling over 1.5 hours and storing at 4°C was used.