Prophylactic salpingectomy for prevention of ovarian cancer at the time of elective laparoscopic cholecystectomy.

BACKGROUND: Most serous ovarian cancers are now understood to originate in the fallopian tubes. Removing the tubes (salpingectomy) likely reduces the risk of developing high-grade serous ovarian cancer. Numerous gynaecological societies now recommend prophylactic (or opportunistic) salpingectomy at the time of gynaecological surgery in appropriate women, and this is widely done. Salpingectomy at the time of non-gynaecological surgery has not been explored and may present an opportunity for primary prevention of ovarian cancer. METHODS: This study investigated whether prophylactic salpingectomy with the intention of reducing the risk of developing ovarian cancer would be accepted and could be accomplished at the time of elective laparoscopic cholecystectomy. Women aged at least 45 years scheduled for elective laparoscopic cholecystectomy were recruited. They were counselled and offered prophylactic bilateral salpingectomy at the time of cholecystectomy. Outcome measures were rate of accomplishment of salpingectomy, time and procedural steps needed for salpingectomy, and complications. RESULTS: A total of 105 patients were included in the study. The rate of acceptance of salpingectomy was approximately 60 per cent. Salpingectomy was performed in 98 of 105 laparoscopic cholecystectomies (93·3 per cent) and not accomplished because of poor visibility or adhesions in seven (6·7 per cent). Median additional operating time was 13 (range 4-45) min. There were no complications attributable to salpingectomy. One patient presented with ovarian cancer 28 months after prophylactic salpingectomy; histological re-evaluation of the tubes showed a previously undetected, focal serous tubal intraepithelial carcinoma. CONCLUSION: Prophylactic salpingectomy can be done during elective laparoscopic cholecystectomy.

ANTECEDENTES: La mayoría de carcinomas serosos de ovario se originan en las trompas de Falopio. La exéresis de las trompas (salpingectomía) probablemente reduce el riesgo de desarrollar un carcinoma seroso ovárico de alto grado. Numerosas sociedades ginecológicas recomiendan efectuar una salpingectomía profiláctica (u oportunista) en el momento de una cirugía ginecológica en determinadas mujeres, y esta conducta está ampliamente difundida. Sin embargo, no se ha analizado la realización de la salpingectomía durante cirugías no ginecológicas como forma de prevención primaria del carcinoma ovárico. MÉTODOS: Determinar si la salpingectomía profiláctica con intención de reducir el riesgo de desarrollar cáncer de ovario sería aceptada y podría llevarse a cabo durante una colecistectomía laparoscópica electiva. Se reclutaron mujeres ≥ 45 años de edad programadas para colecistectomía laparoscópica electiva. A todas ellas se les aconsejó y ofreció la realización de una salpingectomía bilateral profiláctica en el momento de su colecistectomía. Las variables analizadas fueron la tasa de realización de la salpingectomía, la duración y las etapas quirúrgicos para efectuar este procedimiento, y las complicaciones. RESULTADOS: La aceptación de la salpingectomía fue aproximadamente del 60%. La salpingectomía se realizó en 98 de 105 colecistectomías laparoscópicas (93%) y no se pudo realizar en 7 pacientes (7%) por escasa visibilidad o adherencias. La mediana del tiempo quirúrgico adicional fue de 13 (rango 4-45) minutos. No hubo complicaciones atribuibles a la salpingectomía. Una paciente presentó cáncer de ovario 28 meses después de la salpingectomía profiláctica; la reevaluación histológica de las trompas mostró un carcinoma intraepitelial seroso focal tubárico (serous tubal intraepithelial carcinoma, STIC) no detectado previamente. CONCLUSIÓN: La salpingectomía profiláctica se puede realizar durante la colecistectomía laparoscópica electiva.

A prognostic nomogram to predict overall survival in patients with platinum-sensitive recurrent ovarian cancer.

BACKGROUND: Patients with platinum-sensitive recurrent ovarian cancer have variable prognosis and survival. We extend previous work on prediction of progression-free survival by developing a nomogram to predict overall survival (OS) in these patients treated with platinum-based chemotherapy. PATIENTS AND METHODS: The nomogram was developed using data from the CAELYX in Platinum-Sensitive Ovarian Patients (CALYPSO) trial. Multivariate proportional hazards models were generated based on pre-treatment characteristics to develop a nomogram that classifies patient prognosis based on OS outcome. We also developed two simpler models with fewer variables and conducted model validations in independent datasets from AGO-OVAR Study 2.5 and ICON 4. We compare the performance of the nomogram with the simpler models by examining the differences in the C-statistics and net reclassification index (NRI). RESULTS: The nomogram included six significant predictors: interval from last platinum chemotherapy, performance status, size of the largest tumour, CA-125, haemoglobin and the number of organ sites of metastasis (C-statistic 0.67; 95% confidence interval 0.65-0.69). Among the CALPYSO patients, the median OS for good, intermediate and poor prognosis groups was 56.2, 31.0 and 20.8 months, respectively. When CA-125 was not included in the model, the C-statistics were 0.65 (CALYPSO) and 0.64 (AGO-OVAR 2.5). A simpler model (interval from last platinum chemotherapy, performance status and CA-125) produced a significant decrease of the C-statistic (0.63) and NRI (26.4%, P < 0.0001). CONCLUSIONS: This nomogram with six pre-treatment characteristics improves OS prediction in patients with platinum-sensitive ovarian cancer and is superior to models with fewer prognostic factors or platinum chemotherapy free interval alone. With independent validation, this nomogram could potentially be useful for improved stratification of patients in clinical trials and also for counselling patients.

The time of diagnosis impacts surgical management but not the outcome of patients with gallbladder carcinoma.

BACKGROUND: Only 50% of gallbladder cancers (GBC) are recognized before operation and the remaining tumors are diagnosed during surgery or afterwards by the pathologist. These situations may demand substantial modifications of the proceeding during surgery as well as the need for reoperation in some cases. Therefore, the time of diagnosis may strongly influence the surgical management of GBC and the prognosis of the patients. METHODS: Records and follow- up of 152 patients with gallbladder carcinoma who underwent surgery between 1980 and 2004 were examined according to the time of diagnosis, TNM staging system, surgical procedures, morbidity and predictors of survival. There were 76 patients with preoperative diagnosis of GBC (50%; group1), 44 patients with intraoperative diagnosis (29%; group 2) and 32 patients (21%; group 3) with postoperatively incidental finding of GBC. In all cases radical resection of the GBC was intended, except in 5 patients from group 1. Surgical procedures comprised from simple cholecystectomy to multivisceral resections. RESULTS: Overall 5-year survival rate was 7% with a significantly better median survival in group 3 (53.2 month), when compared to only 6.1 month (group 2) and 5.4 month (group 1), respectively. Findings at operation forced significant modifications of the surgical strategy in 85%. Complete resection of GBC was achieved in 38% of the patients. Stage- dependent survival was comparable between the groups following R0 resection. Tumor stage, in particular the nodal status and radicality of the procedure, but not the time of diagnosis were the most powerful predictors of outcome. CONCLUSIONS: Complete tumor resection may provide long-term survival even in locally advanced GBC. Although the time of diagnosis of GBC causes significant changes of the intended procedures during and after surgery, it has no influence on the prognosis provided that radical (R0) resection was accomplished.

Effects of melengestrol acetate and P.G. 600 on fertility in Rambouillet ewes outside the natural breeding season.

The effects of melengestrol acetate (MGA) and P.G. 600 on ewe fertility outside the natural breeding season were evaluated. Rambouillet ewes were assigned to one of four groups: (1) control (C; n=92); (2) PG600 (n=86); (3) MGA (n=99); and (4) MGA+PG600 (n=92). A pellet with or without MGA (0.3mg/ewe/d) was fed at 0.15kg/ewe/d for 7d. On the last day of pellet feeding, ewes were given either saline or 5mL of P.G. 600 i.m. (400IU equine chorionic gonadotropin (eCG) and 200IU human chorionic gonadotropin (hCG)). Ultrasonography was performed between Days 20 and 25 of gestation for ewes that were mated during the first 6 d of the breeding period from the MGA (n=15) and MGA+PG600 (n=8) groups, and the number of luteal structures and embryos were counted. During the first 6d of the breeding period, MGA increased (P<0.05) the percentage of ewes that mated and conceived when compared to C and PG600 (24.2% vs. 3.3% and 10.5%, respectively). Relative to MGA, the mean (+/-S.E.M.) number of luteal structures per ewe was enhanced (P<0.03) in MGA+PG600 (1.53+/-0.13 vs. 2.38+/-0.42, respectively), however as pregnancy progressed, the number of embryos (1.5+/-0.13 vs. 1.8+/-0.16, respectively) and lambs born (1.3+/-0.15 vs. 1.5+/-0.27, respectively) did not differ. Treatment with MGA reduced (P<0.01) the interval from ram introduction to lambing relative to groups that did not receive MGA (168+/-0.8d vs. 171+/-0.6d, respectively). In conclusion, treatment with MGA increased the percentage of ewes conceiving early in the breeding period. Although P.G. 600 increased the number of luteal structures present per ewe, it did not significantly enhance ewe prolificacy.

Aggrecan-like biomimetic proteoglycans (BPGs) composed of natural chondroitin sulfate bristles grafted onto a poly(acrylic acid) core for molecular engineering of the extracellular matrix.

Biomimetic proteoglycans (BPGs) were designed to mimic the three-dimensional (3D) bottlebrush architecture of natural extracellular matrix (ECM) proteoglycans, such as aggrecan. BPGs were synthesized by grafting native chondroitin sulfate bristles onto a synthetic poly(acrylic acid) core to form BPGs at a molecular weight of approximately ∼1.6 MDa. The aggrecan mimics were characterized chemically, physically, and structurally, confirming the 3D bottlebrush architecture as well as a level of water uptake, which is greater than that of the natural proteoglycan, aggrecan. Aggrecan mimics were cytocompatible at physiological concentrations. Fluorescently labeled BPGs were injected into the nucleus pulposus of the intervertebral disc ex vivo and were retained in tissue before and after static loading and equilibrium conditioning. BPGs infiltrated the tissue, distributed and integrated with the ECM on a molecular scale, in the absence of a bolus, thus demonstrating a new molecular approach to tissue repair: molecular matrix engineering. Molecular matrix engineering may compliment or offer an acellular alternative to current regenerative medicine strategies. STATEMENT OF SIGNIFICANCE: Aggrecan is a natural biomolecule that is essential for connective tissue hydration and mechanics. Aggrecan is composed of negatively charged chondroitin sulfate bristles attached to a protein core in a bottlebrush configuration. With age and degeneration, enzymatic degradation of aggrecan outpaces cellular synthesis resulting in a loss of this important molecule. We demonstrate a novel biomimetic molecule composed of natural chondroitin sulfate bristles grafted onto an enzymatically-resistant synthetic core. Our molecule mimics a 3D architecture and charge density of the natural aggrecan, can be delivered via a simple injection and is retained in tissue after equilibrium conditioning and loading. This novel material can serve as a platform for molecular repair, drug delivery and tissue engineering in regenerative medicine approaches.

Supplementation of metabolizable protein during late gestation and fetal number impact ewe organ mass, maternal serum hormone and metabolite concentrations, and conceptus measurements.

To examine the effects of maternal metabolizable protein (MP) supplementation during late gestation on serum hormone and metabolites and organ masses, multiparous ewes (n = 45) carrying singletons or twins were allotted randomly (within pregnancy group) to 1 of 3 treatments: 60% (MP60), 80% (MP80), or 100% (MP100) of MP requirements. Blood samples were drawn before the initiation of diets (day 100) and before slaughter (day 130) for chemistry panel analysis and weekly for hormone analysis including progesterone (P4) and estradiol-17ß (E2). At day 130, ewe organ masses were recorded. Despite being fed isocaloric diets, MP60 ewes gained less weight throughout pregnancy compared with MP80 and MP100 ewes which were similar. Although diet did not impact E2 or P4 concentrations, ewes carrying twins had greater (P < 0.05) concentrations of both as gestation advanced. Albumin, aspartate aminotransferase, and total protein were reduced (P < 0.05) in MP60 compared with MP100 ewes near term. There was a diet by fetal number interaction (P = 0.03) for lactate dehydrogenase. Twin-carrying MP80 ewes had greater lactate dehydrogenase compared with all other groups on day 130 of gestation. Ewes that were fed MP80 had greater body weight on day 130 of gestation compared with MP60 ewes. Kidney and heart weights were lighter in MP60 ewes compared with MP80 ewes. There was a maternal diet by fetal number interaction (P = 0.05) on fetal weight per unit empty ewe body weight. In ewes carrying singletons, MP60 ewes supported less fetal weight compared with MP100. In contrast, MP60 ewes supported more fetal mass compared with MP100 ewes when carrying twins. The level of protein, and not just total energy, in the diet appears to impact some aspects of the maternal system. Moreover, it appears some measurements of mobilizing maternal body resources are enhanced in ewes carrying twins.

Effects of dried distiller's grains and lasalocid inclusion on feedlot lamb growth, carcass traits, nutrient digestibility, ruminal fluid volatile fatty acid concentrations, and ruminal hydrogen sulfide concentration.

Our hypothesis was that increasing the inclusion level of dried distiller's grains with solubles (DDGS) to feedlot lambs would increase growth and the inclusion of lasalocid (LAS; Bovatec, Alpharma, LLC, Bridgewater, NJ) would increase ADG and G:F, while not affecting digestibility, ruminal VFA concentration, and ruminal pH. Furthermore, we hypothesized that rations containing LAS and higher levels of DDGS would cause increased ruminal hydrogen sulfide gas (HS) concentrations. Two hundred forty crossbred (Suffolk × Rambouillet) lambs (31.9 ± 5.87 kg BW; approximately 90 d of age) were allocated to 6 treatments in a completely randomized design with a 3 × 2 factorial arrangement of treatments. Lambs were placed into 24 feedlot pens (4 pens/treatment; 10 lambs/pen) for a 111 d finishing study. Main effects included concentration of DDGS (0, 15, or 30% DM basis) and inclusion of LAS (0 or 22.05 g/metric ton LAS) resulting in treatments of: 1) 0% DDGS without LAS (0DDGS-NL), 2) 0% DDGS with LAS (0DDGS-L), 3) 15% DDGS without LAS (15DDGS-NL), 4) 15% DDGS with LAS (15DDGS-L), 5) 30% DDGS without LAS (30DDGS-NL), and 6) 30% DDGS with LAS (30DDGS-L). Two-day weights were taken at the beginning and end of the experiment. Two-hundred-eighteen lambs (64.8 ± 7.99 kg BW) were slaughtered on d 112 at a commercial abattoir and carcass data collected. The inclusion of LAS increased ( ≤ 0.02) final BW, ADG, G:F, and HCW. As DDGS in the ration increased to 30%, DMI decreased linearly ( = 0.03) while G:F increased linearly ( = 0.03). A second study was conducted utilizing the same treatments to evaluate N and S balance, ruminal VFA and H2S concentration, and ruminal pH in 24 crossbred wethers (Suffolk × Rambouillet; 41.2 ± 12.23 kg BW). Daily urinary sulfur excretion and ruminal H2S concentration were linearly increased ( < 0.001) as DDGS increased in the ration. Total ruminal VFA concentration linearly decreased ( = 0.002) as DDGS increased in the ration. The inclusion of LAS increased ( = 0.02) ruminal pH. The results confirm our hypothesis that LAS increased overall growth and increasing DDGS increased ruminal HS concentration but did not influence growth. We reject the hypothesis that the combined effects of LAS and DDGS would have no effect on rumen pH and VFA concentrations.

Impacts of supplemental arginine on the reproductive performance of fall lambing ewes.

In sheep, embryonic and fetal death during pregnancy can account for 25% to 50% of the total number of corpora lutea (and thus potential embryos). The objective of this study was to determine the effects of injectable and oral Arg supplementation provided for 14 d postbreeding on the reproductive performance of naturally stimulated fall lambing ewes. Rambouillet ewes ( = 210) were exposed to rams equipped with marking harnesses to induce cyclicity in April 2012. Upon estrus detection (d 0) ewes were randomly assigned, in a completely random design, to 1 of 6 treatments for a 14-d treatment period: injectable saline (CON; = 25), injectable Ala (IVALA; = 20), injectable Arg (IVARG; = 23), oral rumen-protected Arg (RPARG; = 20), oral fish meal (FM; = 24), or oral soybean meal (SBM; = 23). Daily treatments, except CON, IVALA, and SBM, were formulated to provide supplemental Arg at 30 mg·kg BW·d and were provided at 0800 h daily. Ewes receiving injectable treatments were provided 454 g corn/d postinjection, whereas ewes receiving oral supplements were provided a ground ration of their respective treatments with corn individually at 0800 h daily. Plasma and serum samples were collected on d 0, 2, 4, 6, 8, 10, 12, and 14 from 12 ewes per treatment to evaluate plasma progesterone and serum AA concentrations. At lambing, birth weight, birth type, and sex were recorded. Weaning weights were recorded when the average age of lambs was 85 d. No differences ( ≥ 0.39) were detected for pregnancy, prolificacy, and lambing rates or lamb birth weights among treatments. However, litter weaning weight tended to be greater ( = 0.06) and weaning rates were greater ( = 0.05) in Arg-injected ewes (1.09, 0.95, 1.29, 0.72, 1.00, and 0.86, respectively). Plasma progesterone and serum Arg concentrations showed a treatment and day effect ( < 0.001), but no treatment × day interaction ( ≥ 0.99) was observed. In contrast to previous research, supplemental Arg during the first 14 d of pregnancy did not improve pregnancy or lambing rates; however, IVARG did positively impact weaning rates.

Supplementing metabolizable protein to ewes during late gestation: II. Effects on ewe lamb performance and reproductive efficiency.

The objective of the current study was to determine the effects of maternal MP intake in isocaloric diets during late gestation on female offspring growth from birth to breeding and measure reproductive performance of those offspring in their first breeding season. In yr 1, maternal dietary treatments were applied at d 100 of gestation, were similar in total energy, and contained 60MP1, 60% of MP requirements; 80MP1, 80% of MP requirements; and 100MP1, 100% of the MP requirements on a DM basis during late gestation. In yr 2, maternal dietary treatments were similar in total energy and contained 60MP2, 60% of MP requirements; 100MP2, 100% of the MP requirements; and 140MP2, 140% of MP requirements on a DM basis during late gestation. While there was a quadratic effect ( = 0.003) for ewe lamb birth weight with the ewe lambs from 80MP1 ewes having increased birth weights compared with ewe lambs from 60MP1 and 100MP1 ewes in yr 1, there was no effect ( ≥ 0.22) of maternal diet on growth of ewe lamb offspring thereafter. A quadratic effect ( = 0.02) was observed for the percentage of ewe lambs bred during the first 17 d of the breeding season, with more ewe lambs born to ewes fed 80MP1 bred compared with ewe lambs born to ewes fed 60MP1 and 100MP1. Ewe lambs giving birth within the first 17 d of lambing season increased ( = 0.001) linearly as MP intake increased in the maternal diet. In yr 2, there was no effect ( ≥ 0.07) of maternal MP treatment during late gestation on growth of ewe lambs and reproductive performance except ADG from birth to weaning and lamb birth weight. There was a quadratic effect ( = 0.01) for ADG from birth to weaning of ewe lambs from ewes consuming 100MP2 being increased compared with ewe lambs from ewes fed 60MP2 and 140MP2. There was a linear ( = 0.04) reduction in birth weight of lambs born to ewe lambs as the dam's maternal dietary MP intake increased. The data from the current study suggest that feeding 80% or 100% of MP requirements during late gestation may have the greatest positive impacts on female offspring reproductive performance.

Maternal metabolizable protein restriction during late gestation on uterine and umbilical blood flows and maternal and fetal amino acid concentrations near term in sheep.

To examine the effects of maternal metabolizable protein (MP) restriction during late gestation on uterine and umbilical blood flows, conceptus size, and amino acid concentrations in the uterine and umbilical vessels, 11 ewes with singleton pregnancies were assigned to one of three isocaloric diets formulated to provide 60% of MP (MP60), 80% of MP (MP80), or 100% of MP (MP100) requirements from days 100 to 130 of gestation. On day 130 of gestation, intraoperative uterine and umbilical blood flows were obtained as well as serum samples from the uterine artery, uterine vein, umbilical artery, and umbilical vein. Ewes on the MP60 diet had lighter (P=0.04) and smaller (P≤0.05) fetuses, but increased (P=0.02) uterine blood flow relative to fetal weight compared with MP100 ewes, with MP80 being intermediate. Umbilical blood flow was similar (P=0.70) across treatments. Glutamine, glycine, isoleucine, leucine, ornithine, serine, and valine concentrations were impacted (P≤0.02) by maternal treatment. While uterine flux of total serum nitrites was greater (P=0.03) in MP60 and MP80 ewes compared with MP100 ewes, fetal flux did not differ. Decreased maternal protein intake resulted in less (P<0.01) maternal cytochrome P450 1A enzyme activity. There were minimal impacts of maternal diet on steroid concentrations. Maternal dietary protein may alter fetal growth by impacting placental vasculature function and nutrient absorptive capabilities.

Selective attention and aphasia in adults: preliminary findings.

Thirteen patients with left-hemisphere stroke and history of aphasia and 13 normal controls were administered the covert orientation of visual attention task (COVAT). This task presents targets to the right or left of a central fixation point after a cue (84% of trials) or with no cue (16% of trials). Left-hemisphere damaged patients also received tests of language function at the time of the study. For targets presented 100 msec after cue onset, normal controls demonstrated equivalent responding for targets to the left and to the right of a central fixation point. Patients with left-hemisphere damage showed slower reaction times when responding to targets on the right as opposed to the left side of space when attention was first cued to the opposite side of space (invalid trials) or when attention was focused on a central fixation point (uncued trials), but they did not show slower reaction times on the right side when attention was first cued to the right (valid trials). For left-sided targets, no differences between valid, invalid, and uncued trials existed. Slower responding to right- as opposed to left-sided targets on invalid and uncued trials was correlated with impaired performance on six of seven language measures for patients with left-hemisphere damage. Implications for the relationship between language and selective attention systems in the left hemisphere are discussed.

Combined imaging and chemical sensing of L-glutamate release from the foregut plexus of the lepidopteran, Manduca sexta.

A new combined imaging and chemical detection sensor for the measurement of localized L-glutamate release at the insect neuromuscular junction (NMJ) is presented. The sensor is comprised of an L-glutamate-sensitive fluorescent gel, spin-coated onto the tip of an optical imaging fiber. The gel is composed of L-glutamate oxidase (GLOD); a pH-sensitive fluorescent dye, SNAFL; and poly(acrylamide-co-N-acryloxysuccinimide) (PAN). NH(3) is liberated from the interaction of L-glutamate with GLOD, which reversibly reduces the emitted fluorescence signal from SNAFL. This sensor has a spatial resolution of 3-4 micro m, and an L-glutamate detection limit of between 10 and 100 micro M. L-glutamate release and re-uptake from the foregut plexus of Manduca sexta was detected by the sensor in the presence of the L-glutamate re-uptake blocker dihydrokainate, and the post-synaptic L-glutamate receptor antagonist CNQX.

Fractional zinc absorption using a single isotope tracer.

BACKGROUND: Fractional absorption of zinc (Zn) has been measured using dual isotopes of Zn given simultaneously. An oral test dose and an intravenous (i.v.) reference dose are administered, followed by the measurement of the double isotopic enrichment (E) in urine 48 h after administration. We postulated that an estimate of the %E in urine for a given i.v. dose of Zn may be used to eliminate the need for venipuncture and the second Zn isotope. OBJECTIVES: To determine a constant (k) for the Zn enrichment of urine after i.v. administration of a dose of labeled Zn in Zn-replete subjects. To use 'k' to calculate fractional absorption of Zn, and to compare these values to values obtained using the standard dual isotope method. DESIGN: Single-arm cohort. SETTING: The Hospital for Sick Children, Toronto, Canada. SUBJECTS: Twenty-three healthy adults were recruited from the Metropolitan Toronto area. Seventeen subjects completed the study. INTERVENTIONS: A 2.29 mg i.v. dose of (67)Zn followed immediately by a 2.50 mg oral dose of (70)Zn. RESULTS: Population mean percentage enrichment (%E) of (67)Zn in urine was 1.43 (95% CI 1.26, 1.60). The ratio of the i.v. dose to mean %E in urine (k) was estimated to be 1.60 mg (95% CI 1.43, 1.82). There was no difference in the mean fractional absorption of Zn calculated using the single compared to the dual isotope method: 12.58% (95% CI 2.22, 22.94) vs 12.68% (95% CI 4.52, 20.85), respectively (P=0.89). The correlation coefficient between the two methods was 0.81 (P<0.0001). CONCLUSIONS: The dual isotope method may be replaced by using a constant (k) and a single oral dose of isotopic-enriched Zn to estimate fractional absorption of Zn within a population. SPONSORSHIP: Gerber Products Company, Fremont, MI.

Influence of rumen protein degradability and supplementation frequency on performance and nitrogen use in ruminants consuming low-quality forage: cow performance and efficiency of nitrogen use in wethers.

Two studies were conducted to determine the influence of CP degradability and supplementation frequency (SF) on ruminant performance and N efficiency. Treatments included an unsupplemented control (CON) and degradable intake protein (DIP; 82% of CP) or undegradable intake protein (UIP; 60% of CP) provided daily, every 3 d, or every 6 d. Seven wethers (36+/-1 kg BW) were used in the digestibility study with DIP and UIP treatments formulated to meet CP requirements. Eighty-four Angus x Hereford cows (512+/-42 kg BW) in the last third of gestation were used for the performance study. The DIP treatments were calculated to provide 100% of the DIP requirement and UIP treatments were provided on an isonitrogenous basis compared with DIP. Basal diets consisted of low-quality (5% CP) meadow hay. Forage DMI and N intake by lambs decreased (P < 0.05) linearly as SF decreased. Additionally, DMI, OM intake, N retention, N digestibility, and digested N retained were greater (P < 0.01) for supplemented wethers than for controls with no difference due to crude protein degradability. Nitrogen balance, DMI, and OM intake decreased linearly (P < 0.05) as SF decreased. Plasma urea (PU; mM) was measured over a 6-d period and supplemented lambs had increased (P < 0.01) PU compared with CON. Plasma urea linearly decreased (P < 0.01) as SF decreased. Pre- and postcalving (within 14 d and 24 h of calving, respectively) cow weight and body condition score change were more positive (P < 0.05) for supplemented groups than for controls. Results suggest CP supplements consisting of 20 to 60% UIP can be effectively used by ruminants consuming low-quality forage without adversely affecting N efficiency and animal performance, even when provided as infrequently as once every 6 d.

Influence of rumen protein degradability and supplementation frequency on steers consuming low-quality forage: I. Site of digestion and microbial efficiency.

Seven cannulated (rumen and duodenal) Angus x Hereford steers (264 +/- 8 kg BW) consuming low-quality forage (5% CP; 61% NDF; 31% ADF) were used to determine the influence of CP degradability and supplementation frequency (SF) on DMI and nutrient digestion. Treatments included an unsupplemented control and degradable intake protein (DIP) or undegradable intake protein (UIP) provided daily, every 3 d, or every 6 d. The DIP treatments (18% UIP) were calculated to provide 100% of the DIP requirement, while the UIP treatments (60% UIP) were provided on an isonitrogenous basis compared with DIP. Forage DMI was not affected by treatment. Total DM and N intake, duodenal N flow, and intestinal N disappearance increased (P < 0.01) with supplementation. Dry matter intake and duodenal N flow responded quadratically (P < 0.04; greatest values on the every-third-day treatments) as SF decreased. However, no differences in N intake or intestinal N disappearance were observed because of CP degradability or SF. Duodenal bacterial N flow and true bacterial N synthesis (g bacterial N/kg of OM truly digested in the rumen) were increased (P < 0.05) with supplementation. Also, duodenal bacterial N flow was greater (P < 0.05) for DIP compared with UIP. Duodenal nonbacterial N flow was increased (P = 0.02) with CP supplementation and for UIP compared with DIP (P < 0.01). Supplemental CP increased (P < 0.01) total tract DM and N digestibility with no difference due to CP degradability or SF. Results suggest CP supplements consisting of 20 to 60% UIP can be effectively used by steers consuming low-quality forage without adversely affecting DMI, nutrient digestibility, or bacterial CP synthesis, even when provided as infrequently as once every 6 d.

Influence of rumen protein degradability and supplementation frequency on steers consuming low-quality forage: II. Ruminal fermentation characteristics.

Seven ruminally and duodenally cannulated steers (264 +/- 8 kg BW) consuming low-quality forage (5% CP; 61% NDF; 31% ADF) were used to determine the influence of CP degradability and supplementation frequency (SF) on ruminal fermentation characteristics. Treatments included an unsupplemented control and degradable intake protein (DIP) or undegradable intake protein (UIP) provided daily, every 3 d, or every 6 d. The DIP treatments (18% UIP) were calculated to provide 100% of the DIP requirement, while the UIP treatments (60% UIP) were provided on an isonitrogenous basis compared with DIP. Ruminal NH3-N was increased on the day all supplements were provided with supplemental CP (P = 0.04) and for DIP compared with UIP (P < 0.01). Also, because ruminal NH3-N increased at a greater rate with DIP compared with UIP as SF decreased, a linear effect of SF x CP degradability interaction (P = 0.02) was observed. In addition, NH3-N was greater on the day only daily supplements were provided for supplemented treatments (P = 0.04), and decreased linearly (P < 0.01) as SF decreased. Concentration of total VFA increased linearly (P = 0.02) as SF decreased on the day all supplements were provided, whereas on the day only daily supplements were provided, total VFA were greater for UIP compared with DIP (P = 0.01), and decreased linearly (P < 0.01) as SF decreased. An interaction concerning the linear effect of SF and CP degradability (P = 0.02) was observed for ruminal liquid volume on the day all supplements were provided. This was the result of an increase in liquid volume with DIP as SF decreased compared with a minimal effect with UIP. In contrast, there was no influence of supplementation on liquid volume the day only daily supplements were provided. Ruminal liquid dilution rate was greater (P = 0.02) with CP supplementation on the day all supplements were provided. We did observe a quadratic effect of SF x CP degradability interaction (P = 0.01) for dilution rate because of a quadratic response with DIP (greatest value with the every-third-day treatment) compared with a decrease as SF decreased for UIP. On the day only daily supplements were provided, ruminal liquid dilution rate decreased linearly (P = 0.02) as SF decreased. These results suggest that DIP and UIP elicit different effects on ruminal fermentation when supplemented infrequently to ruminants consuming low-quality forage while not adversely affecting nutrient intake and digestibility.

Daily and alternate-day supplementation of urea or biuret to ruminants consuming low-quality forage: II. Effects on site of digestion and microbial efficiency in steers.

Five steers (491 +/- 21 kg BW) were used in an incomplete 5 x 4 Latin square with four 24-d periods to determine the influence of supplemental non-protein N (NPN) source and supplementation frequency (SF) on nutrient intake and site of digestion in steers consuming low-quality grass straw (4% CP). Treatments (TRT) included an unsupplemented control and a urea- or biuret-containing supplement placed directly into the rumen daily (D) or every other day (2D) at 0700. The NPN treatments were formulated to provide 90% of the estimated degradable intake protein requirement. Daily TRT were supplemented CP at 0.04% of BW/d, whereas the 2D TRT were supplemented at 0.08% of BW every other day. Therefore, all supplemented TRT received the same quantity of supplemental CP over a 2-d period. Forage OM intake was not affected (P > 0.05) by NPN supplementation, NPN source, or SF; however, total OM and N intake were increased (P < 0.01) with CP supplementation. Duodenal flow of N was greater (P = 0.04) with CP supplementation compared with the control. In addition, duodenal bacterial N flow was increased with CP supplementation (P = 0.04) and for biuret compared with urea (P < 0.01). Bacterial efficiency (g bacterial N/kg OM truly digested in the rumen) was greater (P = 0.05) for biuret than for urea. Apparent total-tract N digestibility was increased with NPN supplementation (P < 0.01) but not affected by NPN source or SF. These results suggest that urea or biuret can be used effectively as a supplemental N source by steers consuming low-quality forage.

Daily and alternate-day supplementation of urea or biuret to ruminants consuming low-quality forage: III. Effects on ruminal fermentation characteristics in steers.

Five ruminally and duodenally cannulated steers (491 +/- 21 kg BW) were used in an incomplete 5 x 4 Latin square with four 24-d periods to determine the influence of supplemental nonprotein N (NPN) source and supplementation frequency (SF) on the dynamics of ruminal fermentation in steers consuming low-quality grass straw (4% CP). Treatments (TRT) included an unsupplemented control (CON) and a urea or biuret supplement that were placed directly into the rumen at 0700 daily (D) or every other day (2D). The NPN treatments were formulated to provide 90% of the estimated degradable intake protein requirement; therefore, the urea and biuret treatments received the same amount of supplemental N over a 2-d period. Daily TRT were supplemented with CP at 0.04% of BW/d, whereas the 2D TRT were supplemented at 0.08% of BW every other day. Forage was provided at 120% of the previous 5-d average intake in two equal portions at 0715 and 1900. Ruminal fluid was collected 0, 3, 6, 9, 12, and 24 h after supplementation on a day of and a day before supplementation for all TRT. Ruminal NH3-N increased (P < 0.04) with CP supplementation on the day all supplements were provided and on the day on which only daily supplements were provided compared with the CON. However, an NPN source x SF interaction (P = 0.03) on the day all supplements were provided indicated that NH3-N increased at a greater rate for urea as SF decreased compared with biuret. Ruminal NH3-N on the day only daily supplements were provided was greater (P = 0.02) for D compared with 2D. On the day all supplements were provided, D increased (P = 0.05) ruminal indigestible acid detergent fiber passage rate and ruminal fluid volume compared with 2D. These results suggest that urea or biuret can be used effectively as a supplemental N source by steers consuming low-quality forage without adversely affecting ruminal fermentation, even when provided every other day.

Self-limiting supplements fed to cattle grazing native mixed-grass prairie in the northern Great Plains.

Objectives of this research were to compare animal performance with or without supplementation, compare effectiveness of three intake limiters, and to examine seasonal changes in nutritive value of native range in south-central North Dakota. Treatments included 1) control (CONT; no supplement); 2) hand-fed (HF) supplement, with no chemical limiter; 3) 16% salt (NACL); 4) 5.25% ammonium chloride and ammonium sulfate (AS); and 5) 7% calcium hydroxide (CAOH). Supplements were based on wheat middlings, barley malt sprouts, and soybean hulls and were formulated to provide 40% of the CP intake and 32% of the NEm intake of 350-kg steers. Trials 1 and 2 each used 70 yearling steers (370.8 +/- 0.04 and 327.9 +/- 0.76 kg initial BW for Trials 1 and 2, respectively). In each year, four 28-d periods from the latter half of June through mid-October were used. Steers were stratified by weight and allotted randomly to treatments in 1 of 10 16-ha pastures (two pastures per treatment for each trial). In Trial 1, diet sampling began in the first 28-d period, but supplementation did not begin until the second 28-d period. In Trial 2, supplementation and diet collection began in the first 28-d period. Cation-anion differences (DCAD; Na + K - Cl - S) for NACL, AS, CAOH, and HF supplements were 151, -735, 160, and 166 mEq/ kg, respectively. In Trial 1, no treatment, period, or treatment x period effects for supplement intake were detected (P > or = 0.29). In Trial 2, a treatment x period interaction for supplement intake occurred (P = 0.005) because HF steers were offered a constant amount of supplement daily, whereas steers fed AS, CAOH, and NACL were allowed to consume ad libitum quantities of supplement. Average daily gain in Trial 1 was not affected (P = 0.21) by supplementation. In Trial 2, NACL, AS, and HF treatments had higher (P < or = 0.07) ADG than CONT. In Trial 1, final weights were not affected by supplementation (P = 0.23). In Trial 2, final weights of NACL- and HF-fed steers were greater than for CONT and CAOH steers (P < 0.10). In Trial 2, CONT steer final weights were lower than all supplemented treatments (P < 0.10). For yearling steers grazing native range, use of NACL as a limiter resulted in increased weight gains compared with using either CAOH or AS; however, no limiter that was tested restricted supplement intake as effectively as HF. More research is necessary to determine the optimum limiter level and the effect of forage quality on supplement intake.