Effect of recombinant porcine somatotropin on growth and carcass quality in growing pigs: interactions with genotype, gender and slaughter weight

Effects of recombinant porcine somatotropin (rpST) on growth, lean tissue growth, feed intake, feed conversion, lean tissue feed conversion, backfat thickness and lean percentage were examined in 96 growing pigs. The experiment used barrows and gilts from the genotypes Duroc, F1 (Dutch Yorkshire x Dutch Landrace) and Pietrain. Half the pigs received 14 mg rpST i.m. twice each week starting at 60 kg; others received a placebo. Pigs had ad libitum access to a diet containing 2,162 kcal net energy and 182 g crude protein per kilogram and were slaughtered at either 100 or 140 kg live weight. From 60 to 100 and from 100 to 140 kg, live weight responses to rpST averaged as follows: daily gain, +4.5 and +19.9%; feed intake, -4.4 and +3.5%; feed conversion, -8.4 and -13.9%; backfat thickness, -13.8 and -22.8%; lean percentage, +4.4 and +8.7%; lean tissue growth rate, +8.6 and +35.8%; and lean tissue feed conversion, -13.1 and -24.9%. No gender x rpST interaction was detected. However, a genotype x treatment interaction was significant for backfat thickness at both slaughter weights, showing a higher response to rpST in Duroc than in Pietrain and F1. Growth performance was improved more by rpST in F1 and Pietrain than in Duroc, especially at higher weights, but carcass traits were improved more by rpST in Duroc. The response to rpST in lean tissue growth rate from 60 to 100 kg was highest in fatter animals (Duroc, barrows), whereas from 100 to 140 kg, response in lean tissue growth rate to rpST was highest in leaner animals (Pietrain, F1, gilts).     

Abundance and survival of infective larvae of the cattle nematodes Cooperia punctata, Haemonchus placei and Oesophagostomum radiatum from faecal pats in a wet tropical climate

Observations were made on the abundance and survival of Haemonchus placei, Cooperia punctata and Oesophagostomum radiatum infective larvae from cattle faecal pats exposed at various times of the year in north Queensland wet tropics. Pats exposed in the hot, wet season yielded abundant larvae on herbage. In the dry season, although low numbers of infective larvae were usual, considerable numbers were produced under conditions of heavy dews on dense herbage. Irrespective of season of deposition of pats, the resulting larvae persisted generally for not longer than 10 to 12 weeks, and in large numbers for only 2 to 6 weeks. The findings suggest that prevention of contamination in the wet season, and in the dry season when light rainfalls are accompanied by heavy dews on dense herbage, will result in low levels of larval infestation on herbage. Rotational grazing in the area is suggested as a means of worm control.     

MEDETOMIDINE-BUTORPHANOL-MIDAZOLAM ANAESTHESIA IN DOGS AND ITS REVERSAL WITH ATIPAMEZOLE: CARDIORESPIRATORY,GENERAL AND ACID-BASE BALANCE EFFECTS

The cardio-respiratory, general and acid-base balance effects induced by medetomidine- butorphanol-midazolam anaesthesia in dogs and its reversal with atipamezole were evaluated. Medetomidine (1000/μg/m², IM) premedication induced a decrease in body temperature, heart rate, systolic arterial blood pressure (SAP), arterial and venous oxygen pressure (PaO₂ & PvO₂), blood pH, Cortisol and insulin as well as potassium levels with all recorded changes remaining within normal ranges. Induction with a mixture of butorphanol (0.1 mg/kg) and midazolam (1.0 mg/kg) intravenously did not affect any of these parameters. Reversal with atipamezole (5000 μg/m², IM) administered one hour after the medetomidine injection, reversed the trend in heart rate, the decline in body temperature, insulin and Cortisol serum levels. A mild decrease in arterial systolic and diastolic blood pressures were noted whereas other relevant parameters remained unchanged.     

Nutrition, key factor to reduce environmental load from pig production

In different parts of Europe animal production is highly concentrated. Pig production generally is the main animal production activity in these areas. Main concerns of these large numbers of pigs are the amount of surplus nutrients in excreta and gaseous losses to the environment. Main nutrients of concern are N, P, and heavy metals and main gaseous losses of concern are ammonia, odour, and methane. Although losses are inevitable to a certain extent, nutrition seems to be a key factor in reducing these losses. Main nutritional strategies to reduce N and P excretions from pigs are: phase feeding (N, P), supplementation of limiting amino acids to the diet (N), and addition of phytase to the diet (P). Nutritional strategies to reduce heavy metals excretions from pigs are: finding alternative, natural, growth promoters that could replace Cu and Zn in the diet; using feedstuffs for the diet that are less contaminated with Cd. Main strategies to reduce ammonia emissions are: 1) lowering crude protein intake in combination with addition of limiting amino acids; 2) Shifting nitrogen excretion from urine to faeces by including fermentable carbohydrates in the diet; 3) lowering pH of urine by adding acidifying salts to the diet; 4) lowering the pH of faeces by inclusion of fermentable carbohydrates in the diet. These strategies proved to be independent from each other and effects are additive. By combining these strategies a total reduction of ammonia emission in growing-finishing pigs of 70% could be reached. Strategies to reduce odour emission are: 1) reducing protein fermentation by balancing available protein and fermentable carbohydrates in the large intestine; 2) Minimizing breakdown of absorbed sulphur amino acids. More studies are needed in this area of research, but results until now are very promising. A clear relationship exists between fermentable carbohydrates in the diet and methane emissions. This disadvantage should be considered when tackling ammonia emission by this strategy. It is concluded that there is a large potential to reduce environmental load within pig dense areas by nutritional means.     

浅议小水电上网电价的制定

小水电上网电价价格与价值出现严重背离,同网不同价、一厂一价等不合理情况例得小水电事业举步维艰,制定一套调整小水电上网电价的方法非常必要。从小水电上网电价制定的几种依据入手,提出了一套小水电上网电价价格制定的步骤,并以淮阴市为例计算出了淮阴市小水电上网电价,具有一定的推广价值。     

Sarcocystosis in a Stillborn Lamb

Confirmed congenital sarcocystosis has been reported extremely rarely in domestic ruminants. Sarcocystosis was diagnosed in a stillborn lamb with microscopic lesions predominantly in the central nervous system and placenta. Encephalitis was characterized by multiple foci of glial nodules some with central necrosis, perivascular cuffing and vascular occlusion, while placental lesions consisted of multifocal necroses, inflammation and mild calcification. Immature and mature schizonts were found in vascular endothelium of several organs. It is suggested that the protozoa were Sarcocystis tenella based on their morphology, location and as this is the most pathogenic Sarcocystis sp. parasitizing sheep.     

Nanoscale Magnetic Domains in Mesoscopic Magnets

The basic magnetic properties of three-dimensional nanostructured materials can be drastically different from those of a continuous film. High-resolution magnetic force microscopy studies of magnetic submicrometer-sized cobalt dots with geometrical dimensions comparable to the width of magnetic domains reveal a variety of intricate domain patterns controlled by the details of the dot geometry. By changing the thickness of the dots, the width of the geometrically constrained magnetic domains can be tuned. Concentric rings and spirals with vortex configurations have been stabilized, with particular incidence in the magnetization reversal process as observed in the ensemble-averaged hysteresis loops.     

An Experimental Model to Study Resistance Index and Systolic/Diastolic Ratio of Uterine Arteries in Adverse Canine Pregnancy Outcome

The aim of this study was to describe the changes in the resistance index (RI) and systolic/diastolic ratio ( S / D ) of the uterine arteries during mid-pregnancy abortion induction in the dog. Sixteen 30–35 day pregnant bitches were randomly assigned to either a pharmacological protocol to interrupt gestation (n = 8) or were used as untreated control group (n = 8). Doppler assessments of uterine arteries blood flow were carried out before the initiation of the protocol and then every other day up to abortion (treated group) or parturition (control group). All treated bitches aborted 6 ± 1.2 days after initiation of the treatment (while none of the non-treated bitches aborted). Pre-treatment RI and S / D did not differ between groups (p > 0.2) while average post-treatment indexes were (mean ± SD): 0.62 ± 0.1 vs 0.53 ± 0.1 (p < 0.01) and 2.96 ± 0.9 vs 2.23 ± 0.3 (p = 0.01), for the treated and non-treated group respectively. Correlations between days to abortion and RI or S / D were 0.75 (p < 0.01) and 0.79 (p < 0.01) and, −0.78 (p < 0.01) and −0.73 (p < 0.01) for the treated and non-treated groups respectively. In the treated group, correlations between serum progesterone (P₄) concentrations and RI and S / D were −0.76 (p < 0.01) and −0.59 (p < 0.01) respectively. It is concluded that, during induction of abortion, RI and S / D of uterine arteries progressively increased while P₄ decreased.     

Impact on beef cattle productivity of infection with anthelmintic-resistant nematodes

ABSTRACT

Aims: The main goal of the current study was to evaluate, on a commercial beef cattle farm, the impact of infection with gastrointestinal nematodes resistant to both ivermectin (IVM) and moxidectin (MXD) on the productivity of calves.

Methods: Male Aberdeen Angus calves, aged 9–11 months, with faecal nematode egg counts (FEC) ≥200 epg and body weight ≥190?kg, were allocated to two herds. Herd A (n?=?90) grazed a maize-winter forage crop rotation and Herd B (n?=?90) grazed a 2-year-old Agropyrum pasture. On Day 0 in each herd, calves were randomly allocated into five groups (n?=?18), which were treated with 0.2?mg/kg IVM; 0.2?mg/kg MXD; 3.75?mg/kg ricobendazole (RBZ), both IVM and RBZ, or remained untreated. Faecal samples collected on Days ?1 and 19 were used to determine the percentage reduction in FEC, and genera of the nematodes were determined by the identification of the third-stage larvae recovered from faecal cultures. Total weight gain was determined from body weights recorded on Days ?1 and 91.

Results: Overall mean reduction in FEC was 42% for IVM, 67% for MXD, 97% for RBZ and 99% for IVM?+?RBZ. The reduction in FEC for Cooperia spp. was ≤78% for IVM and MXD, and for Haemonchus spp. was 0 and 36% for IVM and MXD, respectively, confirming the presence of parasites resistant to both anthelmintics. Only IVM?+?RBZ treatment resulted in 100% efficacy against Haemonchus spp. The overall estimated mean total weight gain for calves treated with IVM was 15.7 (95% CI?=?11.9–19.7) kg and for calves treated with IVM?+?RBZ was 28.8 (95% CI?=?25–32.5) kg (p?<?0.001). Mean total weight gain for calves treated with MXD was 23.5 (95% CI?=?19.7–27.2) kg.

Conclusions and clinical relevance: In calves naturally infected with resistant nematodes, under the production system assessed here, weight gains were lower in calves treated with anthelmintics that were moderately or highly ineffective compared to those treated with highly effective anthelmintics. These results demonstrate to farmers and veterinarians the importance of a sustainable and effective nematode control under field conditions.     

Calm Temperament Improves Reproductive Performance of Beef Cows

Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus‐cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85‐day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus‐cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two‐point chute exit–gait scoring method was repeatable and identified cattle with an excitable temperament.