Use of ultrasound to predict body composition changes in steers at 100 and 65 days before slaughter

Steers from research crossbreeding projects (n = 406) were serially scanned using real-time ultrasound at 35-d intervals from reimplant time until slaughter. Cattle were evaluated for rump fat depth, longissimus muscle area (ULMA), 12th-rib fat thickness (UFAT), and percentage of intramuscular fat (IMF) to determine the ability of ultrasound to predict carcass composition at extended periods before slaughter. Additional background information on the cattle, such as live weight, ADG, breed of sire, breed of dam, implant, and frame score was also used. Carcass data were collected by trained personnel at "chain speed," and samples of the 12th-rib LM were taken for ether extract analysis. Simple correlation coefficients showed positive relationships (P < 0.01) between ultrasound measures taken less than 7 d before slaughter and carcass measures: ULMA and carcass LM area (CLMA, r = 0.66); UFAT and carcass 12th-rib fat thickness (CFAT, r = 0.74); and IMF and carcass numeric marbling score (r = 0.61). The same correlation coefficients for ultrasound measures taken 96 to 105 d before slaughter and carcass values (P < 0.01) were 0.52, 0.58, and 0.63, respectively. Steers were divided into source-verified and nonsource-verified groups based on the level of background information for each individual. Regression equations were developed for the carcass measurements; 46% of the variation could be explained for CLMA and 44% of CFAT at reimplant time, 46% of the variation in quality grade and 42% of the variation in yield grade could be explained. Significant predictors of quality grade were IMF (P < 0.001), natural log of 12th-rib fat thickness (LUFAT, P < 0.001), and ADG (P < 0.01), whereas LUFAT (P < 0.001), ULMA (P < 0.01), live weight (P < 0.001), hip height (P < 0.001), and frame score (P < 0.001) were significant predictors of yield grade. Regressions using ultrasound data taken 61 to 69 d before slaughter showed increasing R2. Live ultrasound measures at reimplant time are a viable tool for making decisions regarding future carcass composition.     

A B-cell targeting virus disrupts potentially protective genomic methylation patterns in lymphoid tissue by increasing global 5-hydroxymethylcytosine levels

The mechanisms by which viruses modulate the immune system include changes in host genomic methylation. 5-hydroxymethylcytosine (5hmC) is the catalytic product of the Tet (Ten-11 translocation) family of enzymes and may serve as an intermediate of DNA demethylation. Recent reports suggest that 5hmC may confer consequences on cellular events including the pathogenesis of disease; in order to explore this possibility further we investigated both 5-methylcytosine (5mC) and 5hmC levels in healthy and diseased chicken bursas of Fabricius. We discovered that embryonic B-cells have high 5mC content while 5hmC decreases during bursa development. We propose that a high 5mC level protects from the mutagenic activity of the B-cell antibody diversifying enzyme activation induced deaminase (AID). In support of this view, AID mRNA increases significantly within the developing bursa from embryonic to post hatch stages while mRNAs that encode Tet family members 1 and 2 reduce over the same period. Moreover, our data revealed that infectious bursal disease virus (IBDV) disrupts this genomic methylation pattern causing a global increase in 5hmC levels in a mechanism that may involve increased Tet 1 and 2 mRNAs. To our knowledge this is the first time that a viral infection has been observed to cause global increases in genomic 5hmC within infected host tissues, underlining a mechanism that may involve the induction of B-cell genomic instability and cell death to facilitate viral egress.     

Effect of Dietary Nonstructural Carbohydrate Content on Activation of 5′‐Adenosine Monophosphate‐Activated Protein Kinase in Liver,Skeletal Muscle,and Digital Laminae of Lean and Obese Ponies

Background

In EMS‐associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5′‐Adenosine‐monophosphate‐activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR.

Hypothesis/Objectives

To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge.

Animals

Twenty‐two mixed‐breed ponies.

Methods

Immunohistochemistry and immunoblotting for total AMPK and phospho(P)‐AMPK and RT‐qPCR for AMPK‐responsive genes were performed on laminar, liver, and skeletal muscle samples collected after a 7‐day feeding protocol in which ponies stratified on body condition score (BCS; obese or lean) were fed either a low‐CHO diet (ESC + starch, approximately 7% DM; n = 5 obese, 5 lean) or a high‐CHO diet (ESC + starch, approximately 42% DM; n = 6 obese, 6 lean).

Results

5′‐Adenosine‐monophosphate‐activated protein kinase was immunolocalized to laminar keratinocytes, dermal constituents, and hepatocytes. A high‐CHO diet resulted in significantly decreased laminar [P‐AMPK] in lean ponies (P = .03), but no changes in skeletal muscle (lean, P = .33; obese, P = .43) or liver (lean, P = .84; obese, P = .13) [P‐AMPK]. An inverse correlation existed between [blood glucose] and laminar [P‐AMPK] in obese ponies on a high‐CHO diet.

Conclusions and Clinical Importance

Laminar tissue exhibited a normal response to a high‐CHO diet (decreased [P‐AMPK]), whereas this response was not observed in liver and skeletal muscle in both lean (skeletal muscle, P = .33; liver, P = .84) and obese (skeletal muscle, P = .43; liver, P = .13) ponies.     

Effect of feeding level on ileal and total tract digestibility of nutrients and energy from soybean meal‐based diets for piglets

A total of 36 piglets with an initial body weight (BW) of 5.6 ± 0.7 kg, fitted with simple T‐cannulas at the distal ileum, were used to evaluate the effect of three graded feeding levels (50, 75 or 100 g/kg BW^0.75 day) on apparent ileal digestibility (AID) and total tract digestibility (ATTD) of dry matter (DM), nitrogen (N) and energy, and on ATTD of organic matter (OM), ether extracts (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF) and digestible (DE), metabolisable (ME) and net energy (NE) content in soybean meal (SBM)–casein–cornstarch‐based diets. The AID of DM, N and energy and ATTD of NDF, ADF and EE in the diets were not affected (p > 0.05) by the feed intake (FI) level. There was a small decrease in ATTD of DM, N (CP), OM, ash and energy, and in DE, ME and NE content in the diets (p < 0.05) with increasing FI level. The net disappearance in the large intestine (in % of ileal recovery) decreased for DM, N and energy (p < 0.05) with increasing FI level. The design of the study allowed for estimating ileal endogenous loss of N and total tract endogenous loss of ash, N and EE, for estimating corresponding true ileal and total tract digestibility values, and for estimating urinary endogenous N loss. High variability in estimates of ileal endogenous N loss and total tract endogenous losses of N, EE and ash reflects great variation in individual endogenous losses between animals. Estimation of true total tract digestibility of N, EE and ash by regression analysis was affected by their decrease in ATTD with increasing FI level, as estimates for true digestibility were lower compared to their apparent values. The present results suggest that FI level can affect both apparent and true total tract nutrient digestibility in piglets.     

Tarsometatarsal subluxation in dogs: partial arthrodesis by plate fixation

In a retrospective study of tarsometatarsal joint subluxation in eight dogs, secondary fractures were identified in six dogs, particularly of the fourth tarsal bone and the proximal fifth metatarsal bone. Common causes of tarsometatarsal joint injury included jumping or falling and direct trauma to the foot. Partial tarsal arthrodesis, with the use of bone-plate stabilization and cancellous bone grafting of joint spaces after removal of articular cartilage, led to progressive bone healing in all dogs. Implant breakage did not occur in any dog.     

Human Dirofilaria repens infection in Hungary: a case in the spermatic cord and a review of the literature

Orchiectomy was performed in a 37-year-old Hungarian man exhibiting a swelling in his right testicle. Histology revealed a nodule attached to the spermatic cord, consisting of a granulomatous tissue around sections of a nematode. The worm was identified as Dirofilaria repens, an uncommon parasite in Hungary. As the patient had been abroad only in Italy where cases of dirofilariosis in dogs and humans are relatively frequent, it is assumed that the infection might have been acquired in that country 5 years earlier. This is the fifth case, published so far in the world, of such a localization in a human. The human cases of dirofilariosis reported in Hungary are reviewed.     

Using current on-line carcass evaluation parameters to estimate boneless and bone-in pork carcass yield as influenced by trim level.

The objective of this study was to develop prediction equations for estimating proportional carcass yield to a variety of external trim levels and bone-in and boneless pork primal cuts. Two hundred pork carcasses were selected from six U.S. pork processing plants and represented USDA carcass grades (25% USDA #1, 36% USDA #2, 25% USDA #3, and 14% USDA #4). Carcasses were measured (prerigor and after a 24 h chill) for fat and muscle depth at the last rib (LR) and between the third and fourth from last rib (TH) with a Hennessy optical grading probe (OGP). Carcasses were shipped to Texas A&M University, where one was randomly assigned for fabrication. Selected sides were fabricated to four lean cuts (ham, loin, Boston butt, and picnic shoulder) then fabricated progressively into bone-in (BI) and boneless (BL) four lean cuts (FLC) trimmed to .64, .32, and 0 cm of s.c. fat, and BL 0 cm trim, seam fat removed, four lean cuts (BLS-OFLC). Total dissected carcass lean was used to calculate the percentage of total carcass lean (PLEAN). Lean tissue subsamples were collected for chemical fat-free analysis and percentage carcass fat-free lean (FFLEAN) was determined. Longissimus muscle area and fat depth also were collected at the 10th and 11th rib interface during fabrication. Regression equations were developed from linear carcass and OGP measurements predicting FLC of each fabrication point. Loin muscle and fat depths from the OPG obtained on warm, prerigor carcasses at the TH interface were more accurate predictors of fabrication end points than warm carcass probe depth obtained at the last rib or either of the chilled carcass probe sites (probed at TH or LR). Fat and loin muscle depth obtained via OGP explained 46.7, 52.6, and 57.1% (residual mean square error [RMSE] = 3.30, 3.19, and 3.04%) of the variation in the percentage of BI-FLC trimmed to .64, .32, and 0 cm of s.c. fat, respectively, and 49.0, 53.9, and 60.7% (RMSE = 2.91, 2.81, and 2.69%) of the variation in the percentage of BL-FLC trimmed to .64, .32, and 0 cm of s.c. fat, respectively. Fat and loin muscle depth from warm carcass OGP probes at the TH interface accounted for 62.4 and 63.5% (RMSE = 3.38 and 3.27%) of the variation in PLEAN and FFLEAN, respectively. These equations provide an opportunity to estimate pork carcass yield for a variety of procurement end point equations using existing on-line techniques.     

The effectiveness of the haemodialysate Solcoseryl for second-intention wound healing in horses and ponies

Second-intention healing of limb wounds in horses is often problematic. Solcoseryl is a protein-free, standardized dialysate/ultrafiltrate (HD) derived from calf blood, which has been shown to improve healing in both animals and humans. The efficacy of HD in the healing of deep wounds in horses and ponies was investigated. Deep wounds of 20 by 35 mm were created on both metatarsi (skin, subcutis, periosteum) and on both femoral biceps muscles (skin, subcutis, muscle) of five horses and five ponies. The wounds on one side were treated with HD, four times a week during the period that the wounds were bandaged and once daily thereafter. The wounds on the other side were left untreated. In the first 4 weeks of the healing period HD stimulated healing but inhibited healing thereafter. This pattern was significant for all wound groups (P < 0.001). Because of this change in effect, the overall effect on wound healing over the entire period was not significant (P = 0.77). HD stimulated healing initially by provoking a greater initial inflammatory response, faster contraction and faster formation of granulation tissue. Subsequently, HD inhibited healing because it significantly delayed epithelialization and caused protracted inflammation. The effects of HD were most pronounced in the horses. Because this study distinguished between contraction and epithelialization, it could be shown that HD stimulated contraction but inhibited epithelialization. Therefore, HD is useful in horses for the treatment of deep wounds during the initial phase of healing by second intention, i.e. during the first weeks when wound contraction can be expected. Treatment should be ceased when epithelialization becomes predominant.