Effects of concentrate‐to‐forage ratios and 2‐methylbutyrate supplementation on ruminal fermentation,bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers

This study evaluated the effects of dietary concentrate levels and 2‐methylbutyrate (2MB ) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate‐concentrate (400 g/kg diet [MC ]) or high‐concentrate (600 g/kg diet [HC ]) diets were fed with or without 2MB (0 g/day [2MB ?] or 15.0 g/day [2MB +]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate‐to‐propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH ₃‐N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus , Ruminococcus flavefaciens , Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α‐amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.     

Variation in egg yolk cholesterol concentration between and within breeds of the domestic fowl.

1. The pattern of variation for egg yolk cholesterol concentration between 5 commercial egg layer lines and a cross of Gallus domesticus is described. 2. Yolk cholesterol concentration in the cross was lower than in the lines, and 6.7% lower than the midparent value. 3. It is proposed that the reduced yolk cholesterol concentration of the cross may be a consequence of heterosis, although sex-linkage and/or maternal effects cannot be discounted. 4. The difference between the cross and parental lines is consistent with a physiological relationship between yolk cholesterol concentration and rate of egg production, but not between yolk cholesterol concentration and yolk weight.     

Experimental Pasteurella multocida pneumonia in calves

Pasteurella multocida was isolated from the lungs of calves that died on a farm in the south of England. This organism was inoculated experimentally into 13 calves by the intratracheal route: in all but two of the calves mild clinical disease resulted and at necropsy, three or four days later, pneumonic consolidation involving up to 22 per cent of the lung was observed. P multocida was isolated from all but two of the lungs. Of two calves inoculated intravenously with P multocida, one showed mild clinical disease and slight pneumonic consolidation at necropsy and the other remained normal. Control calves inoculated intratracheally and intravenously with sterile broth showed no signs of illness and no pneumonic consolidation. Histologically the lung lesions comprised a fibrinous bronchopneumonia with variable sized areas of coagulative necrosis, extensive deposition of fibrin and massive dilatation and oedema of the interlobular and pleural lymphatics. It is concluded that P multocida should receive more recognition as a primary pathogen.     

Effects of zinc sulfate concentration and feeding frequency on ruminal protozoal numbers, fermentation patterns and amino acid passage in steers

Effects of zinc sulfate (0 vs 1,142 ppm supplemental zinc from zinc sulfate) and feeding frequency (1 x vs 12x daily) on ruminal protozoa numbers, fermentation patterns and amino acid passage were investigated using four ruminally and abomasally cannulated mature Jersey steers in a 4 x 4 Latin square experiment. Steers (530 kg) were fed a 50:50 roughage:concentrate diet at 1.5 times their NEm requirement. Experimental periods were 14 d in duration; ruminal, abomasal and fecal samples were collected at 6-h intervals during the last 3 d of each period. Protozoa numbers tended to be lowest (1.82 x 10(6)/ml) in steers fed zinc 1 x and tended to be highest (3.83 x 10(6)/ml) in steers fed zinc 12 x daily (P less than .10). Frequent feeding decreased ruminal pH .24 units and increased total VFA 20.7%, ammonia 22.7% and ruminal digestion of dietary amino acids (AA) 61.6% (P less than .05). Zinc supplementation decreased ruminal digestion of dietary AA 35.8% (P less than .05) and the abomasal passage of bacterial OM and AA 21.2% (P less than .05) and increased ruminal output of amino acids as a percentage of intake 15.1% (P less than .05). Although it increased escape of dietary AA, zinc sulfate decreased postruminal passage of bacterial AA and resulted in a net negative effect on total postruminal AA passage as a percentage of intake. The effects of zinc on ruminal AA digestion may be more closely related to an interaction of zinc with dietary CP rather than to an effect of Zn on ruminal microbial populations.     

Bread-Making Quality Indices in Triticum aestivum Progenies. Implications in Breeding for Better Bread Wheat

Bread-making quality indices (dough strength and dough mixing stability) in relation to flour protein content, glutenin/gliadin ratio, and high-molecular-weight (HMW) subunits of glutenin have been investigated in Triticum aestivum progenies during a three year agronomic trial. Dough strength (W) proved to be a fairly stable characteristic, slightly but positively correlated with flour protein content. High could be associated with a high glutenin/gliadin ratio as well as with the presence of specific HMW. subunits of glutenin, while high protein content tended to favour a balanced dough tenacity-extensibility ratio (P/L = 0.4—0.6). Satisfactory values of dough-mixing stability were frequently observed in association with good expression of W showing that the two quality traits may coexist without much difficulty in the same genotype. From the plant breeding standpoint the data suggest feasible to obtain high dough strength by concentrating in a genotype the HMW subunits of glutenin known to have a beneficial effect on W. However, very high W may present unfavourable P/L ratios. This possibility is enhanced when the flour has a low protein content which often occurs in high yielding genotypes.     

Effects of oxypolygelatin and dextran 70 on hemostatic variables in dogs

Objective To evaluate and compare coagulation variables following the administration of oxypolygelatin and dextran 70 to clinically healthy dogs. Study design Randomized cross‐over experimental study. Animals A total of eight healthy adult female Beagles aged 2–4 years old and weighing 11.8 ± 2.7 kg. Methods The dogs received a 15‐minute intravenous (IV) infusion of 5 mL kg^?1 oxypolygelatin or 10 mL kg^?1 6% dextran 70. Before (PRE) and at 2, 5, and 24 hours after administration, packed cell volume (PCV), total solids concentration (TS), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), platelet numbers (Plat), factor VIII coagulant activity (VIII:C), von Willebrand factor antigen concentration (vWf:Ag) and platelet function and buccal mucosal bleeding time (BMBT) were measured. Platelet function was assessed using aggregation and by measuring ATP release from aggregating platelets over 6 minutes, with 20, 10, and 5 µm ADP and 5 and 10 µg of collagen mL^?1 as platelet activation agonists. Results All baseline values were within our normal ranges, except for one dog that had low vWf:Ag PRE values prior to both dextran and oxypolygelatin administration. Following dextran and oxypolygelatin administration, the PCV and TP were significantly (p < 0.05) decreased. Plat, FIB, and vWf:Ag decreased, while BMBT and VIII:C increased following dextran administration. Dextran also caused a significant decrease in platelet aggregation in response to ADP. Oxypolygelatin caused a significant decrease in vWf:Ag, Plat, and FIB compared to PRE values. The total amount of ATP released, standardized to platelet number, did not vary significantly for either group at any sampling time from PRE values. No significant changes from PRE values were noted at any time in either group for PT or APTT. Conclusion At the doses administered, both dextran and oxypolygelatin can interfere with hemostatic variables in healthy dogs, but dextran's effect is more profound and prolonged when compared to oxypolygelatin. Clinical relevance Oxypolygelatin causes fewer hemostatic abnormalities when compared to dextran, making it a superior colloid for administration at the doses tested.     

Soya-lecithin in extender improves the freezability and fertility of buffalo (Bubalus bubalis) bull spermatozoa

Egg yolk is routinely used as a cryoprotectant in semen extenders. However, it may contain cryoprotective antagonists, and there are hygienic risks associated with its use. Proteins of plant origin, like soya-lecithin, lack these hazards. The aim of this study was to use soya-lecithin as a cryoprotectant in extender and to investigate its effects on in vitro quality and in vivo fertility of buffalo semen. Semen from three buffalo bulls was frozen in tris-citric extender containing 5.0%, 10% or 15% soya-lecithin or 20% egg yolk. Sperm motility, plasma membrane integrity and viability were assessed post-dilution, pre-freezing and post-thaw. In Post-dilution and pre-freezing, the values for motility, plasma membrane integrity and viability remained higher (p ≤ 0.05) in extenders containing 10% soya-lecithin and control compared with extender containing 5% and 15% soya-lecithin. However, motility, plasma membrane integrity and viability were higher (p < 0.05) in extender containing 10% soya-lecithin compared with control and extenders containing 5% and 15% soya-lecithin. Semen from two buffalo bulls was frozen in tris-citric extender containing either 10% soya-lecithin or 20% egg yolk. Higher (p < 0.05) fertility rate was recorded in buffaloes inseminated with semen containing 10% soya-lecithin (56%) compared with 20% egg yolk (41.5%). The results suggest that 10% soya-lecithin in extender improves the freezability and fertility of buffalo bull spermatozoa and can be used as an alternate to egg yolk in cryopreservation of buffalo semen.     

Effect of condensed tannins on egg hatching and larval development of Trichostrongylus colubriformis in vitro

The effects of condensed tannins extracted from seven forages on the viability of the eggs and first stage (L1) larvae of the sheep nematode Trichostrongylus colubriformis were evaluated in in vitro assays. The extracts of condensed tannins were obtained from Lotus pedunculatus (LP), Lotus corniculatus (LC), sulla (Hedysarum coronarium), sainfoin (Onobrychus viciifolia), Dorycnium pentaphylum (DP), Dorycnium rectum (DR) and dock (Rumex obtusifolius). Extracts containing 200 to 500 microg/ml reduced the proportion of eggs that hatched. The larval development assay was used to evaluate the effect of the extracts on the development of either eggs or L1 larvae to L3 infective larvae. Development was allowed to proceed for seven days by which time the larvae in control incubations had reached the infective L3 stage. Extracts containing 200 microg/ml from LP, DP, DR or dock prevented egg development, and only 11, 8 and 2 per cent of the eggs developed to L3 larvae with extracts from LC, sulla and sainfoin, respectively. When the concentration was 400 microg/ml no eggs developed to L3 larvae. The addition of the extracts after hatching also inhibited the development of L1 to L3 larvae; 200 microg/ml extracted from LP, LC, sulla, sainfoin, DP, DR and dock resulted in only 14, 18, 17, 15, 14, 16 and 4 per cent of L1 larvae developing to the L3 stage compared with 85 per cent for controls, and 400 microg/ml further reduced the development of L1 larvae. Statistical analyses showed that when the extracts were added before hatching they were significantly (P<0.001) more effective at inhibiting the larval development than when they were added after hatching. The condensed tannins from dock had the greatest inhibitory effect on egg development followed by the tannins from DR, sainfoin, DP, LP, sulla and LC.     

A three‐dimensional cell culture system as an in vitro canine mammary carcinoma model for the expression of connective tissue modulators

In this study, derived complex carcinoma (CC) and simple carcinoma (SC) cell lines were established and cultured under two‐dimensional (2D) and three‐dimensional (3D) conditions. The 3D was performed in six‐well AlgiMatrix? (LifeTechnologies®, Carlsbad, CA, USA) scaffolds, resulting in spheroids sized 50–125 µm for CC and 175–200 µm for SC. Cell viability was demonstrated up to 14 days for both models. Epidermal growth factor receptor (EGFR) was expressed in CC and SC in both systems. However, higher mRNA and protein levels were observed in SC 2D and 3D systems when compared with CC (P < 0.005). The connective tissue modulators, metalloproteinases‐1, ‐2, ‐9 and ‐13 (MMPs), relaxin receptors 1 and 2 (RXR1 and RXR2) and E‐cadherin (CDH1) were quantitated. All were upregulated similarly when canine mammary tumour (CMT)‐derived cell lines were cultured under 3D AlgiMatrix, except CDH1 that was downregulated (P < 0.005). These results are promising towards the used of 3D system to increase a high throughput in vitro canine tumour model.     

The selenium status of dairy herds in Prince Edward Island

Bulk tank milk selenium (Se) concentration was compared with mean serum Se concentration in 15 herds and was found to be an accurate reflection of the herd Se status. The Se status of 109 Prince Edward Island (PEI) dairy herds was monitored for 1 year using bulk tank milk Se concentration. Fifty-nine percent of the herds surveyed were, at some point, found to be marginal or deficient in Se, putting them at risk of disease and suboptimal production. The periods of greatest risk of deficiency were fall and winter, at which time 5% and 4%, respectively, of herds sampled fell in the range considered truly deficient in Se. Herds in which Se supplementation was provided in the form of a commercial dairy concentrate were over 4 times more likely to be Se-adequate than herds not using this method, and adjusted average daily milk yield was 7.6% greater in herds determined to be Se-adequate when compared with Se-marginal herds. We conclude that many dairy producers in PEI are providing insufficient supplementary Se in the ration to meet the recommended Se intake for lactating cows.