Comparison of in situ techniques to evaluate the recovery of indigestible components and the accuracy of digestibility estimates

Indigestible components, including indigestible dry matter (iDM) and indigestible neutral detergent fiber (iNDF), play an integral role as internal markers for determining ruminal kinetics and digestibility estimations. However, the accuracy of internal markers is dependent upon the incubation technique utilized as bag type (BT) and incubation length (IL) can be significant sources of error. Previous studies have primarily focused on iDM and iNDF as digestibility markers, but few studies have compared digestibility estimates to those of acid detergent insoluble ash (ADIA). Therefore, our objective was to investigate the effect of BT (F57, F58, and Dacron) and IL (288 and 576 h) on iDM and iNDF residues, DM and NDF digestibilities, and fecal recoveries when using in situ incubations. Additionally, we evaluated the accuracy of digestibility estimates when using iDM, iNDF, and ADIA. For iDM and iNDF, feed residues demonstrated a BT × IL interaction (P < 0.01). However, fecal residues were only influenced by the main effects of BT and IL (P < 0.01), with the F58 BT and 288-h IL having the greatest residues for both iDM and iNDF. The variation in residues was greatly reduced when using iNDF compared with iDM. Fecal recovery estimates most closely approximated 100% recovery when utilizing ADIA and iDM using the F57 × 576 h incubation method (P < 0.01), although recovery was overestimated for all incubation combinations. Fecal NDF recovery estimates better represented the excretion profiles when the F57 × 576 h combination was used with iDM as the internal marker (P < 0.01). Estimates of DM and NDF digestibility were the most accurate when utilizing ADIA (P < 0.01) relative to all other treatments. Our results indicate that the proper methodological application is specific to the purpose of the inferences. When evaluating fecal recoveries and digestibility, ADIA or iDM with F57 at 576-h in situ incubation provides the greatest accuracy.     

Camelids: new players in the international animal production context

Tropical Animal Health and Production - The Camelidae family comprises the Bactrian camel (Camelus bactrianus), the dromedary camel (Camelus dromedarius), and four species of South American...     

Effects of clinical mastitis and puerperal diseases on reproductive efficiency of dairy cows

Tropical Animal Health and Production - The objective of this study was to evaluate the effects of clinical mastitis (CM) occurring before or after the first AI postpartum, and puerperal diseases...     

Comparison between haplotype-based and individual snp-based genomic predictions for beef fatty acid profile in Nelore cattle

The aim of this study was to evaluate the genomic predictions using the single-step genomic best linear unbiased predictor (ssGBLUP) method based on SNPs and haplotype markers associated with beef fatty acids (FAs) profile in Nelore cattle. The data set contained records from 963 Nelore bulls finished in feedlot (±90 days) and slaughtered with approximately 24 months of age. Meat samples from the Longissimus dorsi muscle were taken for FAs profile measurement. FAs were quantified by gas chromatography using a SP-2560 capillary column. Animals were genotyped with the high-density SNP panel (BovineHD BeadChip assay) containing 777,962 markers. SNPs with a minor allele frequency and a call rate lower than 0.05 and 0.90, respectively, monomorphic, located on sex chromosomes, and with unknown position were removed from the data set. After genomic quality control, a total of 469,981 SNPs and 892 samples were available for subsequent analyses. Missing genotypes were imputed and phased using the FImpute software. Haplotype blocks were defined based on linkage disequilibrium using the Haploview software. The model to estimate variance components and genetic parameters and to predict the genomic values included the random genetic additive effects, fixed effects of the contemporary group and the age at slaughter as a linear covariate. Accuracies using the haplotype-based approach ranged from 0.07 to 0.31, and those SNP-based ranged from 0.06 to 0.33. Regression coefficients ranged from 0.07 to 0.74 and from 0.08 to 1.45 using the haplotype- and SNP-based approaches, respectively. Despite the low to moderate accuracies for the genomic values, it is possible to obtain genetic progress trough selection using genomic information based either on SNPs or haplotype markers. The SNP-based approach allows less biased genomic evaluations, and it is more feasible when taking into account the computational and operational cost underlying the haplotypes inference.     

Use of negative pressure wound therapy in three horses with open,infected olecranon bursitis

This article describes the clinical use of negative pressure wound therapy (NPWT) in three horses with an open and infected subcutaneous olecranon bursa, in which prior surgical excision followed by primary closure was unsuccessful. The wounds filled in rapidly with granulation tissue and contracted during therapy. All wounds subsequently went on to heal without complications. The use of NPWT was well tolerated in all three horses and facilitated healing in a difficult area.     

Epidemiological,pathological and immunohistochemical aspects of 125 cases of feline lymphoma in Southern Brazil

A retrospective study compiling cases of feline lymphoma diagnosed during 12 years (2004‐2016) in Southern Brazil was performed. A total of 125 cases of lymphoma diagnosed in cats were reviewed, and information including age, breed, sex and tumour topography were collected. FeLV and FIV immunohistochemical tests were performed, as well as immunophenotyping of lymphomas. The alimentary form represented the most common presentation (42/125), followed by mediastinal lymphoma (35/125). Out of 125 cases, 79 presented positive retroviral immunostaining in tumour tissue (52 FeLV alone, 14 FIV alone and 13 presented FIV and FeLV co‐infections), 66/125 of the cases were of T‐cell origin and 59/125 of the cases were of B‐cell origin. The median age of cats with T‐cell lymphoma was 120 months (10‐240 months), and 60 months (6‐204 months) for cats with B‐cell lymphoma. The most frequent alimentary tumour presentation was the enteropathy‐associated T‐cell lymphoma (type 1), and the major type of mediastinal tumour observed was diffuse large B‐cell lymphoma. Considering only mediastinal and alimentary lymphomas (n = 77), the prevalence of mediastinal lymphoma in FeLV‐positive cats was 2.21 times higher than the prevalence of this type of tumour in FeLV‐negative cats (P = .036). Mediastinal lymphoma was more frequently observed in younger cats, and the prevalence of mediastinal tumours in these animals was 3.06 times higher than the prevalence of this tumour form in old cats (P = .0125). The present study indicates that retroviral infections still play an important role in the development of feline lymphomas in southern Brazil.     

Across-country genomic predictions in Norwegian and New Zealand Composite sheep populations with similar development history

The goal of this study was to assess the feasibility of across-country genomic predictions in Norwegian White Sheep (NWS) and New Zealand Composite (NZC) sheep populations with similar development history. Different training populations were evaluated (i.e., including only NWS or NZC, or combining both populations). Predictions were performed using the actual phenotypes (normalized) and the single-step GBLUP via Bayesian inference. Genotyped NWS animals born in 2016 (N = 267) were used to assess the accuracy and bias of genomic estimated breeding values (GEBVs) predicted for birth weight (BW), weaning weight (WW), carcass weight (CW), EUROP carcass classification (EUC), and EUROP fat grading (EUF). The accuracy and bias of GEBVs differed across traits and training population used. For instance, the GEBV accuracies ranged from 0.13 (BW) to 0.44 (EUC) for GEBVs predicted including only NWS, from 0.06 (BW) to 0.15 (CW) when including only NZC, and from 0.10 (BW) to 0.41 (EUC) when including both NWS and NZC animals in the training population. The regression coefficients used to assess the spread of GEBVs (bias) ranged from 0.26 (BW) to 0.64 (EUF) for only NWS, 0.10 (EUC) to 0.52 (CW) for only NZC, and from 0.42 (WW) to 2.23 (EUC) for both NWS and NZC in the training population. Our findings suggest that across-country genomic predictions based on ssGBLUP might be possible for NWS and NZC, especially for novel traits.     

Oestrogen and Progesterone Receptors and COX‐2 Expression in Endometrial Biopsy Samples During Maternal Recognition of Pregnancy in Llamas (Lama glama)

Endometrial expression of oestrogen receptor‐α (ERα), progesterone receptor (PR) and cyclooxigenase‐2 (COX‐2) was evaluated in non‐pregnant and pregnant llamas during the period when luteolysis/maternal recognition of pregnancy is expected to occur. Females (n = 28) were divided into two groups: non‐pregnant llamas were induced to ovulate with a Buserelin injection, and endometrial biopsies were obtained on day 8 (n = 5) or 12 (n = 5) post‐induction of ovulation. Animals of the pregnant group (n = 18) were mated with a fertile male. Pregnancy was confirmed by the visualization of the embryo collected by transcervical flushing in 5 of 9 animals on day 8 post‐mating and by progesterone profile on day 12 post‐mating in 4 of 9 animals, when endometrial biopsies were obtained. An immunohistochemical technique was used to evaluate receptors population and COX‐2 expression. Pregnant llamas showed a higher percentage of positive cells and stronger intensity for ERα than for non‐pregnant llamas in stroma on day 8 and in the luminal epithelium on day 12 post‐induction of ovulation, while a deep decrease in endometrial PR population was reported in pregnant llamas on that day in luminal and glandular epithelia and stroma. In the luminal epithelium, COX‐2 expression was lower in pregnant than in non‐pregnant animals. Briefly, the increase of ERα in pregnant llamas gives further support to the hypothesis that oestrogens are involved in the mechanism of maternal recognition of pregnancy. Endometrial PR decrease in pregnant llamas might be a necessary event to allow the expression of proteins involved in conceptus attachment, a mechanism widely accepted in other species. Moreover, embryo seems to attenuate maternal PGF_2α secretion during early pregnancy by decreasing the endometrial expression of COX‐2 in the luminal epithelium of pregnant llamas.