Embodied Resources in Fish and Shrimp Feeds

Global averages were obtained for amounts of energy, land, water, wildfish, nitrogen, and phosphorus embodied in aquaculture feed ingredients. These data allowed amounts of these embodied resources to be calculated for typical feed formulations for channel catfish, Ictalurus punctatus; hybrid catfish, I. punctatus♀ × I. furcatus♂; Vietnamese catfish, Pangasius spp.; Atlantic salmon, Salmo salar; rainbow trout, Oncorhynchus mykiss; tilapia, Oreochromis spp.; whiteleg shrimp, Litopenaeus vannamei; and black tiger shrimp, Penaeus monodon. Embodied resource use per m.t. of feed varied among species: energy, 4.90–12.48 GJ/m.t.; land, 0.082–0.312 ha/m.t.; water, 502–1227 m³/m.t.; wildfish, 0–2880 kg/m.t.; nitrogen, 3.08–8.63 kg/m.t.; phosphorus, 1.16–5.62 kg/m.t. These calculations did not account for variations in site‐specific factors related to embodied resources and feed composition and use. But they suggest that reducing feed conversion ratio (FCR) by 0.1 unit for the seven species (species groups) could potentially reduce feed use by around 1.1 million tonne (Mt) while conserving 9.8 million GJ of energy, 270,000 ha of agricultural land, 1.4 billion m³ of freshwater, and 1.24 Mt of wildfish. Reduction of the FCR is a powerful means of lessening farm‐level production costs and negative impacts of feed production and use.     

Relationships between acid-base balance, serum composition and colostrum absorption in newborn calves

Twenty-seven newborn Holstein bull calves were bottle-fed 2 litres of pooled colostrum which had been stored at -20 degrees C. Blood gas analysis before feeding showed a partially compensated respiratory acidosis in most of the calves, although they all appeared to be clinically normal. Mean venous blood pH was 7.346, carbon dioxide tension (PCO2) was 57.5 mmHg (7.6 kPa), bicarbonate was 30.6 mmol/l and base excess was 3.82 mmol/l. Mean serum IgG1 increased to 8.1 g/l after feeding colostrum. Several significant positive correlations were observed between post-absorptive serum protein, IgG1, IgM, gamma-glutamyltransferase (gamma GT) and D-xylose. Calves with either low serum albumin, high serum CK or low serum gamma GT before feeding tended to have less absorption of colostral protein. It was concluded that reduced absorption of IgG1 from colostrum is associated with hypercapnia in apparently healthy newborn calves.     

Spectral analysis of zooplankton spatial heterogeneity

Continuous estimates were obtained of zooplankton abundance, chlorophyll fluorescence, and water temperature along 10-to 100-kilometer transects of the North Sea. Spectral analysis methods were applied to the data. The "patchiness" of the plankton was distributed over all the length scales resolved with no indication of a characteristic patch size. The relative intensity of the zooplankton patchiness was greater than that of the phytoplankton at all spatial scales, with this difference becoming progressively greater for finer-scale features. In the North Sea data, the concentrations of phytoplankton and zooplankton consistently showed negative spatial correlations.     

Organic Carbon and Dissolved Oxygen Budgets for a Commercial‐Size,In‐pond Raceway System

Intensive production of ictalurid catfish in the USA has increased over the past several years, and a better understanding of the amount of organic carbon (OC) and dissolved oxygen (DO) in these culture environments is needed. Budgets for OC and DO were estimated over a production season (March to November) for an in‐pond raceway system for channel catfish, Ictalurus punctatus, and hybrid catfish (channel catfish × blue catfish, Ictalurus furcatus), with co‐culture of paddlefish, Polyodon spathula, and Nile tilapia, Oreochromis niloticus. Feed input ranged from 45 to 263 kg/ha/d with an overall average of 80 kg/ha/d. Production of each kilogram of live catfish required 1.5 kg of feed and released into the water 0.70 kg of OC, and led to the synthesis of an additional 3.36 kg of OC by photosynthesis. Consequently, production of 1 kg of live catfish resulted in 4.06 kg OC, and harvest of catfish accounted for only 29.5% of OC applied from the feed. Removal of OC increased to 34.3% with the additional harvest of paddlefish and tilapia. OC was consumed in respiration, and some OC accumulated in sediment. Total respiration within the system exceeded the DO produced by photosynthesis, while diffusion and mechanical aeration aided in maintaining suitable DO levels for fish production.     

Evaluation of concurrent perineal hernia in adult male dogs presenting with nontraumatic,acquired inguinal hernias

A possible association between the development of nontraumatic, acquired inguinal hernias (NAIH) and perineal hernias (PH) has been postulated in adult dogs. The objective of this study was to evaluate the frequency of concurrent diagnosis of PH in dogs presented with NAIH and determine potential risk factors for concurrent PH and NAIH. Medical records of adult male dogs presented for NAIH to 4 hospitals between 2007 and 2017 were retrospectively reviewed. Twenty-one dogs with NAIH were included, 8 of which had concurrent PH. There were no significant differences between dogs with and without PH; however, among dogs with both conditions, intact dogs (8.1 ± 1.4 years) were younger than neutered dogs (11.7 ± 1.0 years; P = 0.007). Thirty-eight percent of male dogs presenting for NAIH had concurrent PH, indicating that these conditions commonly occur together. Dogs presenting for NAIH should be carefully evaluated for concurrent PH before surgical intervention.     

Nutritional approaches to slow late finishing pig growth: implications on carcass composition and pork quality

Although pork producers typically aim to optimize growth rates, occasionally it is necessary to slow growth, such as when harvest facility capacity is limited. In finishing pigs, numerous dietary strategies can be used to slow growth so pigs are at optimal slaughter body weights when harvest facility capacity and/or access is restored. However, the impact of these diets on pork carcass quality is largely unknown. Thus, this study aimed to evaluate the efficacy of dietary strategies to slow growth in late finishing pigs and evaluate their effects on carcass composition and pork quality. Mixed-sex pigs (n = 897; 125 ± 2 kg BW) were randomly allotted across 48 pens and assigned to 1 of 6 dietary treatments (n = 8 pens/treatment): (1) Control diet representative of a typical finisher diet (CON); (2) diet containing 3% calcium chloride (CaCl₂); (3) diet containing 97% corn and no soybean meal (Corn); (4) diet deficient in isoleucine (LowIle); (5) diet containing 15% neutral detergent fiber (NDF) from soybean hulls (15% NDF); and (6) diet containing 20% NDF from soybean hulls (20% NDF). Over 42 d, pen body weights and feed disappearance were collected. Pigs were harvested in 3 groups (14, 28, and 42 d on feed) and carcass data collected. From the harvest group, 1 loin was collected from 120 randomly selected carcasses (20 loins/treatment) to evaluate pork quality traits. Overall, ADG was reduced in CaCl₂, Corn, and 20% NDF pigs compared with CON pigs (P < 0.001). However, ADFI was only reduced in CaCl₂ and 20% NDF pigs compared with CON (P < 0.001). Feed efficiency was reduced in CaCl₂ and Corn pigs compared with CON (P < 0.001). Hot carcass weights were reduced in CaCl₂ pigs at all harvest dates (P < 0.001) and were reduced in Corn and 20% NDF pigs at days 28 and 42 compared with CON pigs (P < 0.001). In general, CaCl₂ and 20% NDF diets resulted in leaner carcasses, whereas the Corn diet increased backfat by 42 d on test (P < 0.05). Loin pH was reduced and star probe increased in CaCl₂ pigs compared with CON pigs (P < 0.05); no treatments differed from CON pigs regarding drip loss, cook loss, color, firmness, or marbling (P ≥ 0.117). Overall, these data indicate that several dietary strategies can slow finishing pig growth without evidence of behavioral vices. However, changes to carcass composition and quality were also observed, indicating quality should be taken into consideration when choosing diets to slow growth.     

Analysis of gene expression of prostaglandin EP4 receptor in canine osteosarcoma

In many human cancers, the expression of the prostaglandin receptor EP4 (EP4R) is associated with the development of malignancy and a poor prognosis. The expression of EP4R has not yet been evaluated in canine tumors. The objective of this study was to characterize the messenger RNA (mRNA) expression of EP4R in canine osteosarcoma (OSA). Gene expression of EP4R was evaluated using RNA in-situ hybridization (RNAscope). In all canine OSA samples evaluated, strong universal positive expression of EP4R was identified. Gene expression was significantly higher in OSA tissue samples than in normal nasal turbinate bone, possibly implicating EP4R in the pathogenesis of canine OSA.     

Comparison of two doses of recombinant human bone morphogenetic protein in absorbable collagen sponges for bone healing in dogs

OBJECTIVE: To determine the effects of 2 doses of recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge (rhBMP-2/ACS) on bone healing in dogs. ANIMALS: 27 adult dogs. PROCEDURES: Dogs underwent a mid-diaphyseal (1-mm) tibial osteotomy (stabilized with external skeletal fixation) and received an ACS containing 0.28 mg (0.2 mg/mL) or 0.56 mg (0.4 mg/mL) of rhBMP-2 or no treatment (control dogs). All dogs were examined daily; bone healing was assessed via radiography and subjective lameness evaluation every 2 weeks. After euthanasia at 8 weeks, tibiae were evaluated biomechanically and histologically. RESULTS: Control dogs required antimicrobial treatment for pin-site-related complications more frequently than did rhBMP-2/ACS-treated dogs. At 4 and 6 weeks, weight bearing was greater in dogs treated with rhBMP-2/ACS (0.2 mg/mL) than in control dogs, albeit not significantly. Compared with control treatment, both doses of rhBMP-2/ACS accelerated osteotomy healing at 4, 6, and 8 weeks, and the 0.2 mg/mL dose enhanced healing at 2 weeks; healing at 6 weeks was greater for the lower-dose treatment than for the higher-dose treatment. Histologically, healing at 8 weeks was significantly improved for both rhBMP-2/ACS treatments, compared with control treatment. Among groups, biomechanical variables did not differ, although less osteotomy-site failures occurred in rhBMP-2/ACS-treated groups. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs that underwent tibial osteotomy, rhBMP-2/ACS (0.2 mg/mL) appeared to accelerate bone healing and reduce lameness (compared with control treatment) and apparently augmented bone healing more than rhBMP-2/ACS (0.4 mg/mL). Compared with control dogs, rhBMP-2/ACS-treated dogs required antimicrobial treatments less frequently.     

Radiographic and functional evaluation of dogs at least 1 year after tibial plateau leveling osteotomy

The progression of osteoarthritis and clinical function in 29 dogs at least 1 year after tibial plateau leveling osteotomy was evaluated. A previously reported radiographic scoring system was used by 3 investigators to evaluate preoperative and postoperative radiographs for evidence of stifle osteoarthritis. The combined scores were then used to evaluate the progression of osteoarthritis. The difference between the preoperative scores, derived from radiographs taken at the time of surgery, and the postoperative scores based on radiographs taken at least 1 year later was modest but statistically significant. Despite this finding, client satisfaction was very good. Clinical function was assessed by using a previously reported client questionnaire. According to owner assessment at least 1 year after surgery, there was a significant improvement in function after tibial plateau leveling osteotomy when compared with the preoperative status. Improvement in function as measured by the client questionnaire did not significantly predict the radiographic osteoarthritis score.