Importance of claw quality in cattle: Review and recommendations to achieve genetic improvement. Report of the E.A.A.P. working group on “claw quality in cattle”

The objective of this report is to review results of research and to discuss recommendations to achieve genetic improvement of claw quality. High claw quality is defined as a low susceptibility for claw disorders and a low need for footcare. The economic importance of claw problems is considerable, with about 25% of dairy cows treated per year. Direct effects are costs of trimming, veterinary costs and forced culling (2–3%). Indirect costs are decreased milk production or daily gain, lower fertility, decrease of herd life, and lower salvage value.Lameness problems are mainly localized in the claws and can have a traumatic, systemic or infectious origin. The claw quality is a product of claw shape, characteristics of the horn and anatomy of the inner structure of the claw. Environmental factors like housing systems, management and nutrition give considerable herd effects. Improvement of claw quality in the short term can be achieved by managemental procedures that will reduce foot and leg problems in confinement.Genetic improvement can give a contribution in the long term. Genetic variation in claw traits and claw disorders are recorded between and within breeds. Heritabilities and additive genetic variation for claw shape measurements (e.g. claw length, claw angle) are high enough to obtain genetic change in these traits. Claw measurements are partly symptoms but also predisposition factors for claw disorders like sole ulcers. Shorter and steeper hind leg claws are favourable predispositions.Veterinary records on claw and leg disorders after treatment yield very low heritabilities. Claw judgements should be replaced by more effective measurements because of low h² and low correlation to claw disorders.Implementation of genetic improvement based on measurements of claw shape (angle, length) may start with a progeny test of 30–50 daughters in first lactation of the most promising A.I. bulls in milk production. Relationships of claw characteristics of young bulls with those of their parents and daughters is recommended for further analysis.     

Effects of Dietary Ampitheoe sp. Powder on Growth and Lipid Contents of Litopenaeus vannamei北大核心CSCD

This experiment was conducted to investigate the effects of dietary Ampitheoe sp. powder on the growth and the contents of astaxanthin, triglyceride (TG), total cholesterol (TCHO) and fatty acids of Litopenaeus vannamei. A total of approximately 6 777 L. vannamei with an initial body weight of (1. 80 ± 0.72) g were randomly divided into 3 groups, and there were 3 replicates (753 shrimp per replicate) in each group. Those shrimp fed diets containing 0 (D0 group), 8. 25% (D8. 25 group) and 33% (D33. 00 group) Ampitheoe sp. powder, respectively. The feeding trial lasted for 40 days. The results showed as follows: 1) the final body weight, weight gain rate, specific growth rate, yield and survival rate in D33.00 group were significantly higher than those in D0 group (P <0.05), whereas the feed conversion ratio was significantly lower than that in D0 group (P <0.05) . However, there was no significant difference between D33.00 group and the D8. 25 group in those indexes (P >0.05) . 2) The astaxanthin content in carapace, hepatopancreas and muscle of L. vannamei in D8.25 and D33. 00 groups was significantly higher than that in D0 group (P < 0. 05); that in D33.00 group was significantly higher than that in D8. 25 group (P < 0. 05) . 3) TG content in haemolymph, hepatopancreas and muscle in D8. 25 and D33. 00 groups was significantly lower than that in D0 group (P < 0.05); the TCHO content in hepatopancreas in D8. 25 group was significantly higher than that in D0 and D33.00 groups (P <0.05); TCHO content in muscle in D33.00 group was significantly higher than that in D0 group (P <0.05) . 4) The contents of eicosapentaenoic acid (EPA) and arachidonic acid (AA) in hepatopancreas in D33.00 group were significantly higher than those in D0 group (P <0.05) . The EPA content in muscle in D33.00 group was significantly higher than that in D0 group (P < 0. 05) . In conclusion, adding Ampitheoe sp. powder into the diet can improve the growth performance, the contents of astaxanthin, EPA and AA in L. vannamei, and affect the accumulation of TG and TCHO, which can be used as a functional diet in aquaculture. Considering the cost, the supplementation level of 8. 25% Ampitheoe sp. powder is more appropriate. © 2023 Chinese Journal of Pediatric Surgery. All rights reserved.     

The influence of nitrogen and defoliation on production and water‐use efficiency of Lolium multiflorum cv. Midmar

Abstract

The objective of this study was to investigate the influence of different nitrogen fertiliser application levels in combination with different defoliation intervals on the dry matter (DM) production and water‐use efficiency of ryegrass (Lolium multiflorum,) cv. Midmar. In a field trial, four nitrogen levels (0, 150, 300 and 450 kg N ha^?1) were combined with five defoliation intervals (every 2, 4, 6 and 8 weeks and twice a season). Soil moisture levels were measured with a neutron hydroprobe and were used to schedule irrigation. The dry matter production, nitrogen‐use efficiency (NUE), plant DM content and water‐use efficiency were influenced (P<0.01) by nitrogen level, defoliation interval, and the interaction between these factors. Total DM production varied from 64 to 20 922 kg DM ha^?1. Dry matter production per unit of applied N decreased with an increase in N level within a defoliation interval. The plant DM content varied from 14.0% to 35.6%. The plant DM content decreased (P<0.05) with increasing N applications, while a lengthening of the defoliation interval resulted in an increase (P<0.05) in the DM content. No difference (P>0.05) was found in total water used when plants received N. Water‐use efficiency varied from 1.2 to 25.8 kg DM ha^?1 mm^?1 water received.     

Serosurvey of pathogens in domestic dogs on the border of No?l Kempff Mercado National Park, Bolivia.

The threat of disease transmission from domestic animals to wildlife has become recognized as an increasing concern within the wildlife community in recent years. Domestic dogs pose a significant risk as reservoirs for infectious diseases, especially for wild canids. As part of a multifaceted ecologic study of maned wolves and other canids in the large, remote No?l Kempff Mercado National Park (NKMNP) in northeastern Bolivia, 40 domestic dogs in two villages and at two smaller settlements bordering the national park were sampled for exposure to canine diseases. High levels of exposure were found to canine distemper virus and canine parvovirus, both of which are known to cause mortality in maned wolves and other carnivores. Moderate to high levels of exposure were found to rabies virus, Ehrlichia canis, and Toxoplasma gondii, as well as significant levels of infection with Dirofilaria immitis. This study reports evidence of exposure to several diseases in the domestic dogs bordering the park. Contact between wild carnivores and dogs has been documented in the sampled villages, therefore dogs likely pose a substantial risk to the carnivores within and near NKMNP. Further measures should be undertaken to decrease the risk of spillover infection from domestic animals into the wild species of this region.     

Short‐term effects of fertilizer and stocking rates on the Bankenveld: 2. Animal production

This article on the short‐term effects of veld fertilization in the Bankenveld, deals with the effects of nitrogenous, phosphatic and potassic fertilization, and stocking rates on beef, mutton and wool production. Increased beef production was obtained by applying nitrogenous (linear to 80 kg N/ha) and phosphatic fertilizer to the veld. Fertilization influenced the production of merino sheep less than that of cattle.

Production per animal decreased and that per unit area increased (to a certain point) as a result of increased stocking rates. The expression of these results as MLU/ha or as ha/MLU influenced the form of the response obtained.

Problems were encountered in utilizing fertilized veld, which influenced the economics of the practice. In spite of poor utilization, on some treatments, it appears that veld fertilization can be profitable in its initial stages.     

Effect of dexmedetomidine vs. acepromazine–methadone premedication on limb to lung circulation time in dogs

The study compared limb-to-lung circulation times (CT) in dogs under general anaesthesia after premedication with dexmedetomidine (DEX) or acepromazine–methadone (ACE–M). Healthy male and female dogs (n = 20) were randomly assigned to receive acepromazine 0.04 mg/kg and methadone 0.2 mg/kg intramuscularly (IM), or DEX 0.01 mg/kg IM. Anesthesia was induced with propofol and maintained with isoflurane at similar concentration in both groups. Mechanical ventilation was started immediately (20 breaths/min; inspiratory to expiratory ratio 1:2) and tidal volume was adjusted to achieve an end-tidal CO₂ concentration (PE’CO₂) of between 3.9 and 5.3 kPa. Ten minutes later arterial blood gas was analyzed and baseline data recorded for 3 minutes. A single dose of sodium bicarbonate 0,5 mEq/kg was administered intravenously over 10 s starting with inspiration. Limb-to-lung CT was defined as the time interval between the start of bicarbonate injection and the recording of the highest PE’CO₂.Following bicarbonate administration, PE’CO2 increased, and then rapidly decreased to baseline in both groups. CT was shorter in the ACE–M group (20 ± 2.3 vs. 27 ± 5.1 s). Bodyweight was higher in the ACE–M group (30.6 ± 3.9 vs. 23.3 ± 6.8 kg). Mean arterial blood pressure was higher in the DEX group (92 ± 9 vs. 73 ± 7 mm Hg) but premedication with DEX significantly prolonged CT compared to premedication with ACE–M.     

Beneficial Effects of Rhodotorula sp. C11 on Growth and Disease Resistance of Juvenile Japanese Spiky Sea Cucumber Apostichopus japonicus

The purpose of this study was to evaluate the effects of dietary administration of the live yeast, Rhodotorula sp. C11, on growth and disease resistance against Vibrio splendidus infection in juvenile Japanese spiky sea cucumber Apostichopus japonicus. Sea cucumbers were fed diets containing Rhodotorula sp. C11 at 0 (control), 10⁴, 10⁵, and 10⁶ CFU/g of feed for 45 d. There were three replicate tanks per dietary treatment. The specific growth rates were higher in all sea cucumbers treated with Rhodotorula sp. C11 than in the controls. Following a challenge with V. splendidus NB13, the cumulative prevalence and mortality of sea cucumbers fed diets supplemented with Rhodotorula sp. C11 were lower than in animals fed the basal diet. In sea cucumbers fed diets supplemented with Rhodotorula sp. C11 for 42 d, the only viable yeast found in the intestine was Rhodotorula sp. C11, which had counts of 1.58–1.98 × 10⁴ CFU/g. No yeast was isolated from the intestine of animals fed the basal diet. For the colonization study, 20 sea cucumbers from each dietary treatment were removed to separate tanks and fed the control diet from day 16 to day 46. The viable yeast (Rhodotorula sp. C11) counts in the intestine decreased to 60–80 CFU/g by day 37. Moreover, as demonstrated by denaturing gradient gel electrophoresis, Rhodotorula sp. C11 colonization of the intestine could be detected until day 46. The differences in culture and PCR-denaturing gradient gel electrophoresis may be due to differences in the sensitivity of both methods. The present result showed that Rhodotorula sp. C11 was able to successfully colonize the intestine of juvenile Japanese spiky sea cucumbers by dietary supplementation, which improved its growth and disease resistance.

Received August 11, 2014; accepted November 14, 2014     

Effect of post‐mortem temperature on chicken M. pectoralis major: Isometric tension and pH profiles

1. The relationship between isometric tension development and pH, as a function of storage temperature between 0° and 40°C, was examined in chicken M. pectoralis major (PM) muscle during the critical 24 h post‐mortem period.

2. The muscle strips incubated at 0°C developed a peak isometric tension of 53.3 g/cm². This occurred after only 17 min incubation when the pH was 7.02, demonstrating the potential of chicken PM muscle to cold shorten. Peak isometric tension at 5°C was considerably lower than that generated at 0°C. However, as this occurred when the muscle pH was still high (6.70), this also indicated some potential to cold shorten at 5°C.

3. At 10° to 30°C, the muscle strips developed mean peak isometric tensions of 18 g/cm² after 6 h incubation by which time the muscle pH had fallen to 6.00, demonstrating a limited potential to rigor shorten. In contrast, those incubated at 40°C developed a peak tension of 54.5 g cm² after 75 min when the muscle pH was also around 6.00, thus indicating the potential for intensive rigor shortening at this temperature. Incubation temperature and the resultant muscle pH therefore determine the potential of chicken PM muscle to either cold shorten or rigor shorten.

4. Despite the differences found in isometric tension profiles, cooked meat texture after isometric tension measurement was not significantly different at any of the temperatures studied primarily because the muscle strips were essentially prevented from shortening.     

Study on The Isozyme of Wild Yak

We have adopted PAGE method to isolate lactic dehydrogenase(LDH)and α-amylase(α-Am)from wild yak's serum and measure the physical-chemical properties of the two components respectively. The results showed that the yak LDH isozyme distributed into five bands. The sequence according to their activity reads as LDH1 ＞ LDH2＞ LDH3 ＞ LDH4 ＞ LDH5. The subunit B is relatively occupied a dominant position. It got a wide operating pH range, high thermal stability,well denature resistance and a fairly large adaptability threshold on the physical-chemical change of surrounding environment. α-Am isozyme distributed into seven bands and also got a wide operating pH range. α-Am isozyme is high sensitivity to environmental temperature.     

Absence of effects of dietary α‐tocopherol on egg yolk pigmentation

1. Three experiments were carried out in which yolk colour and carotenoid content were measured in hens fed diets containing soyabean oil or tallow and supplemented with 0, 10, 20, 40, 80, 160 or 320 mg tocopheryl acetate.

2. Fat type had no consistent effect on yolk carotenoid content but yolk α‐tocopherol concentrations were lower with the soyabean oil diet.

3. Yolk concentrations of all carotenoids measured and yolk colour were unaffected by dietary α‐tocopherol concentration.