Do combined applications of crop residues and inorganic fertilizer lower emission of N2O from soil?

Emissions of N₂O were measured following addition of ¹⁵N‐labelled residues of tropical plant species [Vigna unguiculata (cowpea), Mucuna pruriens and Leucaena leucocephala] to a Ferric Luvisol from Ghana at a rate of 100 mg N/kg soil under controlled environment conditions. Residues were also applied in different ratio combinations with inorganic N fertilizer, at a total rate of 100 mg N/kg soil. N₂O emissions were increased after addition of residues, and further increased with combined (ratio) applications of residues and inorganic N fertilizer. However, ¹⁵N‐N₂O production was low and short‐lived in all treatments, suggesting that most of the measured N₂O‐N was derived from the applied fertilizer or native soil mineral N pools. There was no consistent trend in magnitude of emissions with increasing proportion of inorganic fertilizer in the application. The positive interactive effect between residue‐ and fertilizer‐N sources was most pronounced in the 25:75 Leucaena:fertilizer and cowpea:fertilizer treatments where 1082 and 1130 mg N₂O‐N/g residue were emitted over 30 days. N₂O (log_e) emission from all residue amended treatments was positively correlated with the residue C:N ratio, and negatively correlated with residue polyphenol content, polyphenol:N ratio and (lignin + polyphenol):N ratio, indicating the role of residue chemical composition in regulating emissions even when combined with inorganic fertilizer. The positive interactive effect in our treatments suggests that it is unlikely that combined applications of residues and inorganic fertilizer can lower N₂O emissions unless the residue is of very low quality promoting strong immobilisation of soil mineral N.     

Effects of iron injection timing on suckling and subsequent nursery and growing-finishing performance and hematological criteria

Two experiments were conducted to evaluate the effects of Fe injection timing after birth on suckling and subsequent nursery and growing-finishing pig performance. The injectable Fe source used in both experiments was GleptoForte (Ceva Animal Health, LLC., Lenexa, KS). GleptoForte contains gleptoferron which is a Fe macromolecule complex. In Exp. 1, a total of 324 newborn pigs (DNA 241 × 600, initially 1.6 ± 0.04 kg body weight [BW]) within 27 litters were used. Two days after birth, all piglets were weighed, and six barrows and six gilts per litter were allotted to 1 of 6 treatments consisting of no Fe injection or 200 mg of injectable Fe provided in a single injection on d 2, 4, 6, 8, or 10 of age. Pigs were weaned (~21 d of age) and allotted to nursery pens with all pigs in each pen having received the same Fe treatment. In Exp. 2, a total of 1,892 newborn pigs (PIC 359 × C40; initially 1.5 ± 0.02 kg BW) within 172 litters were used. One day after birth, piglets were weighed, and 11 pigs within each litter were allotted to 1 of 6 treatments consisting of no Fe injection or 200 mg of injectable Fe provided on d 1, 3, 5, or 7 of age, or 200 mg on d 1 plus 200 mg on d 12 of age. Pigs were weaned (19 d of age) and placed in a commercial wean-to-finish facility in a total of 15 pens with equal representation of treatments in each pen. In both experiments, not providing an Fe injection after birth decreased (P < 0.05) preweaning average daily gain (ADG), weaning weight, and hemoglobin and hematocrit values compared with all other treatments. In Exp. 1, increasing the age that piglets received an Fe injection until 4 or 6 d after birth provided marginal evidence for an improvement (quadratic; P = 0.070) in preweaning ADG. For the nursery period, increasing the age that piglets received an Fe injection improved (quadratic; P = 0.013) d 80 BW, but there was no evidence of a difference (P > 0.10) in d 173 BW at the end of the grow-finish period. In Exp. 2, increasing the age that piglets received a 200 mg Fe injection showed no evidence of difference (P > 0.10) for subsequent nursery and growing-finishing ADG. In both experiments, hemoglobin and hematocrit values were decreased (linear; P < 0.05) at weaning with increasing age when pigs received an Fe injection. These experiments suggest that providing a 200 mg Fe injection within 7 d after farrowing is sufficient for optimizing preweaning and subsequent growth performance.     

Effect of hay type on cecal and fecal microbiome and fermentation parameters in horses

The effect of hay type on the microbiome of the equine gastrointestinal tract is relatively unexplored. Our objective was to characterize the cecal and fecal microbiome of mature horses consuming alfalfa or Smooth Bromegrass (brome) hay. Six cecally cannulated horses were used in a split-plot design run as a crossover in two periods. The whole plot treatment was ad libitum access to brome or alfalfa hay fed over two 21-d acclimation periods with subplots of sampling location (cecum and rectum) and sampling hour. Each acclimation period was followed by a 24-h collection period where cecal and fecal samples were collected every 3 h for analysis of pH and volatile fatty acids (VFA). Fecal and cecal samples were pooled and sent to a commercial lab (MR DNA, Shallowater, TX) for the amplification of the V4 region of the 16S rRNA gene and sequenced using Illumina HiSeq. The main effects of hay on VFA, pH, and taxonomic abundances were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of hay, hour, location, period, and all possible interactions and random effect of horse. Alpha and beta diversities were analyzed using the R Dame package. Horses fed alfalfa had greater fecal than cecal pH (P ≤ 0.05), whereas horses fed brome had greater cecal than fecal pH (P ≤ 0.05). Regardless of hay type, total VFA concentrations were greater (P ≤ 0.05) in the cecum than in feces, and alfalfa resulted in greater (P ≤ 0.05) VFA concentrations than brome in both sampling locations. Alpha diversity was greater (P ≤ 0.05) in fecal compared with cecal samples. Microbial community structure within each sampling location and hay type differed from one another (P ≤ 0.05). Bacteroidetes were greater (P ≤ 0.05) in the cecum compared with the rectum, regardless of hay type. Firmicutes and Firmicutes:Bacteroidetes were greater (P ≤ 0.05) in the feces compared with cecal samples of alfalfa-fed horses. In all, fermentation parameters and bacterial abundances were impacted by hay type and sampling location in the hindgut.     

Of rodents and ruminants: a comparison of small noncoding RNA requirements in mouse and bovine reproduction

Ruminants are major producers of meat and milk, thus managing their reproductive potential is a key element in cost-effective, safe, and efficient food production. Of particular concern, defects in male germ cells and female germ cells may lead to significantly reduced live births relative to fertilization. However, the underlying molecular drivers of these defects are unclear. Small noncoding RNAs, such as piRNAs and miRNAs, are known to be important regulators of germ-cell physiology in mouse (the best-studied mammalian model organism) and emerging evidence suggests that this is also the case in a range of ruminant species, in particular bovine. Similarities exist between mouse and bovids, especially in the case of meiotic and postmeiotic male germ cells. However, fundamental differences in small RNA abundance and metabolism between these species have been observed in the female germ cell, differences that likely have profound impacts on their physiology. Further, parentally derived small noncoding RNAs are known to influence early embryos and significant species-specific differences in germ-cell born small noncoding RNAs have been observed. These findings demonstrate the mouse to be an imperfect model for understanding germ-cell small noncoding RNA biology in ruminants and highlight the need to increase research efforts in this underappreciated aspect of animal reproduction.     

Effects of vaccination against brucellosis and clostridia on the intake,performance, feeding behavior,blood parameters,and immune responses of dairy heifers calves

The aim of this study was to identify possible effects of different vaccination strategies (concomitantly or not) against brucellosis and clostridia on intake, performance, feeding behavior, blood parameters, and immune responses of dairy heifers calves. Fifty heifers calves were enrolled [38 Gyr (Zebu, Bos taurus indicus) and 12 5/8 Holstein Gyr]. At 120 d of age, animals were randomly distributed among 3 groups: B (n = 18), vaccinated against brucellosis; C (n = 14), vaccinated against clostridia and CB (n = 18), vaccinated concomitantly for both. Rectal and thermographic temperatures were evaluated on days 1, 0, 1, 2, 3, 5, 7,10, 14, and 28 relatives to the vaccination day. Feed and water intake, body weight (BW), and feeding behavior were monitored daily by an electronic feeding system. Blood was sampled on days 0, 3, 7, 14, and 28, relative to the vaccination day for determination of glucose and -hydroxybutyrate (BHBA) concentrations. Blood sampled on day 0 (prevaccination) and on days 28 and 42 were used to evaluate the immune response against Brucella abortus and clostridia. There was an increase in rectal temperature between the first and the third day postvaccination in the 3 groups. The thermography revealed an increase of local temperature for 7 d on groups B and CB. Group C had increased local temperature for a longer period, lasting for up to 14 d. Dry mater intake was reduced for groups B and CB, but no alteration was observed for group C. No alterations regarding initial BW, final BW, average daily weight gain, and feed efficiency were observed. No differences were observed for the 3 vaccination groups for blood parameters throughout the evaluation period. The concomitant vaccination against brucellosis and clostridia led to lower neutralizing antibody titers against epsilon toxin of Clostridium perfringens and botulinum toxin type C of C. botulinum (C > CB > B). When cellular proliferation assay and serological tests to B. abortus were evaluated, no differences were observed between groups B and CB. The present results indicate that the concomitant vaccination against brucellosis and clostridia has no relevant impact on the intake, performance, and feeding behavior of dairy calves. However, the concomitant vaccination of vaccines against these 2 pathogens impacts animal immunity against clostridial infections.     

Influence of amount and frequency of protein supplementation to ruminants consuming low-quality cool-season forages: efficiency of nitrogen utilization in lambs and performance of gestating beef cows

We evaluated the influence of amount and crude protein (CP) supplementation frequency (SF) on nitrogen (N) use by wethers and the performance of late-gestation beef cows. In exp. 1, seven Western whiteface wethers (31.8 ± 1.4 kg) were used in an incomplete 7 × 4 Latin square to evaluate intake and N use. Wethers received one of the seven treatments in a 2 × 3 factorial design containing two levels of supplemental soybean meal offered at a rate of 100% (F) or 50% (H; 50% of F) of the estimated CP requirement daily, once every 5, or once every 10 d, plus a non-supplemented control (CON). Low-quality cool-season forage (4.9 % CP; dry matter [DM] basis) was provided daily for ad libitum intake. Experimental periods lasted 30 d. In exp. 2, 84 Angus × Hereford cows (560 ± 35 kg) were stratified by age, body condition score (BCS), and expected calving date and allocated to 1 of the 21 feedlot pens (three pens per treatment). Pens were randomly assigned to receive the same treatments as in exp. 1 and cows had free access to low-quality cool-season forage (2.9% CP; DM basis). Cow body weight (BW) and BCS were measured every 14 d until calving and within 24 h after calving. In exp. 1, supplementation did not alter total DM and organic matter (OM) intake (P ≥ 0.26), but both parameters linearly decreased as SF decreased (P = 0.02). Supplementation increased DM, OM, and neutral detergent fiber (NDF) digestibility (P ≤ 0.02). Additionally, F feeding linearly increased DM, OM, and NDF digestibility as SF decreased (P ≤ 0.04). Digestibility of N, N balance, and digested N retained were greater with supplementation (P < 0.01), and N digestibility linearly increased as SF decreased (P = 0.01). Mean plasma urea-N concentration was not only greater (P < 0.01) for supplemented vs. CON wethers but also greater (P = 0.03) for F vs. H. In exp. 2, pre-calving BCS change was greater (P = 0.03) for supplemented cows. A linear effect of SF × supplementation rate for pre-calving BCS change was noted (P = 0.05), as F-supplemented cows lost more BCS compared with H as SF decreased. When considering supplementation intervals greater than 5 d, reducing the quantity of supplement provided, compared with daily supplementation, may be a feasible management strategy to maintain acceptable nutrient use and animal performance while reducing supplement and labor costs.     

Retracted: Mycobacterium bovis BCG Danish Strain 1331 isolated from a periarticular lesion in a domestic cat

A 7-year-old male neutered domestic shorthair outdoor cat was referred for chronic left forelimb lameness, which had been treated with intra-articular injections of triamcinolone acetonide. A soft tissue swelling around the elbow joint, extending from the distal humerus to the proximal ulna, was surgically explored and biopsy samples obtained. Mycobacterium bovis was cultured from samples from the soft tissue and bone. The mycobacteria from the media were killed and the DNA extracted and tested on a multiplex real-time PCR for the absence of specific genes and the presence of mycobacterial genus markers. The PCR revealed bacillus Calmette-Guérin Danish Strain 1331; this was also isolated from the prescapular lymph node, muscle and bone, obtained at post mortem examination. Badgers had been vaccinated with the bacillus Calmette-Guérin vaccine SSI (Statens Serum Institute) in the area where the cat lived, in the spring and autumn of the previous year. To the authors' knowledge, this is the first report of infection with M. bovis bacillus Calmette-Guérin Danish Strain 1331 in a domestic cat, potentially associated with annual vaccination of badgers in the proximity of the cat's home.