Effects of pre-feeding of a corn silage-based supplement on the feed intake, milk production and nitrogen utilization of grazing dairy cows

Four Holstein cows were used to determine the effect of timing of the feeding of a corn silage (CS)‐based supplement on the feed intake, milk production and nitrogen utilization of grazing dairy cows. The cows were fed the supplement 2 h before grazing (pre‐grazing) or immediately after grazing (post‐grazing). Cows were grazed for 5 h per day under a rotational grazing system. There was no difference in the herbage and total feed intake between treatments. The milk protein yield for pre‐grazing tended to be higher than that for post‐grazing, whereas the milk yield did not differ between treatments. The total nitrogen intake for pre‐grazing tended to be higher than that for post‐grazing (P = 0.06). There was no difference in the urinary nitrogen output between treatments, whereas the proportion of urinary nitrogen output : total nitrogen intake for pre‐grazing tended to be lower than that for post‐grazing (P = 0.06). The milk nitrogen output and nitrogen retention for pre‐grazing tended to be higher than that for post‐grazing (milk nitrogen, P = 0.06; nitrogen retention, P = 0.05). Nitrogen utilization of grazing dairy cows was improved by feeding a CS‐based supplement before grazing.     

Age and growth of alfonsino Beryx splendens from the Kanto District, central Japan, based on growth increments on otoliths

ABSTRACT:   Age and growth of alfonsino Beryx splendens (Lowe) were studied using counts of presumed daily incremental growth rings on the transverse section of otoliths of fish collected from the Kanto District, central Japan. Microstructural growth increments were observed from the core to the outermost margin of the broadest of approximately 50 branches formed on the surface of an otolith. Of 98 otoliths examined, 46 were readable. The number of increments and fish lengths ranged from 448 (218 mm fork length [FL]) to 3701 (411 mm FL). The ages of these fish were estimated to be 1 year, 2 months and 10 years, 2 months, respectively, assuming that an increment was formed daily. The von Bertalanffy growth equation combined for males and females was expressed as follows: L _t  = 542 {1 −  exp  [−0.133( t  + 2.00)]}, where L _t is fork length (mm) at yearly age t . The results of the present study were compared with those of other researchers who had studied alfonsino from central Japan.     

The abundance of juvenile yellowtail (Seriola quinqueradiata) near the Kuroshio: the roles of drifting seaweed and regional hydrography

We assess the effect of drifting seaweed (Sargassum sp.) biomass, geography and hydrography on juvenile yellowtail (Seriola quinqueradiata) abundance variation off the southeast coast of Japan, near the Kuroshio Current. The amount of drifting seaweed mats progressively increased northeastward into the cooler, coastal waters. Frontal structure indexed using a station‐to‐station ΔSST did not explain spatial variation in the seaweed mat distribution, although the western extent of the Kuroshio Current appeared to act as a boundary. Juvenile yellowtail constituted 51–62% of the fish collected in association with drifting seaweed mats in April 1996 and 1997 and 29% in June 1996. The abundance of juvenile yellowtail was positively correlated with seaweed biomass. The geographic distribution of juvenile yellowtail associated with drifting mats varied among sampling periods, being more southwesterly in April and more northeasterly in June. Simple multiple regression models based on seaweed biomass and geographic distribution (latitude) explained between 35% and 43% of the variation in juvenile yellowtail abundance in spring. Associations with spatial and temporal variations in hydrographic conditions did not contribute to explained variation in a meaningful manner. The results presented here indicate that, off the southeast coast of Japan during April, yellowtail juveniles are likely to be most abundant when seaweed biomass is high, occur offshore, and are bounded by the western extent of the Kuroshio Current near the 19–20°C SST isotherm.     

Effect of feeding non-fibrous carbohydrate before grazing on intake and nitrogen utilization in dairy cows throughout the grazing season

Ten lactating cows were used to determine the effect of feeding non-fibrous carbohydrate (NFC) supplement before grazing on feed intake and nitrogen (N) utilization throughout a grazing season. The experiment was conducted from June to September. Cows grazed twice a day (2.5 h × 2) under a set stocking system and were fed NFC supplement (1 kg/4 kg of milk yield) 2 h before grazing (PRE) or immediately after grazing (POST). Cows were also fed a grass and corn silage mixture ad libitum. Herbage dry matter intake (DMI) was greater for PRE than for POST throughout the experiment and decreased from June to September. Conversely, silage DMI was less for PRE than for POST throughout the experiment and increased over the grazing season. Consequently, total DMI for PRE did not differ from that for POST. Milk urea-N concentration and urinary urea-N excretion in June did not differ between the treatments, whereas that after July was higher for PRE than for POST. Proportion of urinary N excretion to absorbed N intake in June was lower for PRE than for POST, but that after July was higher for PRE than for POST. Feeding NFC supplement before grazing would improve N utilization when cows eat large amounts of herbage high in N.     

Effects of supplementary corn silage on the feed intake and milk production of time-restricted grazing dairy cows

The effects of supplementary corn silage (CS) of either 2 or 4 kg of dry matter (DM; S + 2 and S + 4, respectively) above the energy requirement for milk production and maintenance for grazing dairy cows (S) were determined. Time‐restricted grazing was used to compare the feed intake, milk production, and nitrogen and energy use of lactating cows. The experiment was carried out on two different pastures using a 3 × 3 Latin square design for each pasture. Cows were grazed for 5 h on a rotational grazing system and were fed concentrate (1 kg per 5 kg of milk yield). Herbage intake was measured using a weighing technique. To calculate the energy and nitrogen use, whole feces and urine were collected. There was no statistical effect of the pastures. Herbage intake decreased by the addition of CS (P = 0.02). The reduction of herbage DM intake per unit consumption of supplementary CS towards the S group were 0.80 and 0.45 kg for the S + 2 and S + 4 groups, respectively. The total DM intake for the S + 4 group was higher than that for the S and S + 2 groups (P = 0.02). Milk yield did not differ among treatments, even though the total DM intake for the S + 4 group was higher than that of the S and S + 2 groups. Nitrogen and energy use did not differ with the addition of CS.     

Nephron segment identification in the normal canine kidney by using lectin histochemistry

Lectin-binding patterns in normal canine kidneys were histochemically investigated using eight lectins. WGA, ConA, and RCA-I showed positive signals in glomerular capillary walls, with signals for RCA-I being detected heterogeneously. In tubular segments, signals for WGA, s-WGA, ConA, and RCA-I were distributed widely from proximal tubules to collecting ducts, whereas those for SBA, PNA, DBA, and UEA-I were localized in thin limbs of the loop of Henle, thick ascending limbs, distal tubules, or collecting ducts. Apart from PNA and UEA-I, lectins showed heterogeneous bindings in collecting ducts with the heterogeneity. UEA-I-positive reactions were restricted to those parts of the distal tubules in close proximity to the glomeruli, and in these parts, signals in the macula densa were markedly stronger than in other regions. Based on the present findings, lectin probes, singly or in combination, could be utilized to identify the affected nephron segment in canine renal pathology.     

A comparative study of chronic kidney disease in dogs and cats: induction of cyclooxygenases

The present study investigated whether renal cyclooxygenase (COX) induction is associated with the severity of chronic kidney disease (CKD) in dogs and cats. The collected kidneys were examined histopathologically and immunohistochemically. The immunoreactivities of COX-1 and COX-2 were evaluated quantitatively, and the correlations to the plasma creatinine concentrations, glomerular size, glomerulosclerosis, interstitial fibrosis, and interstitial cell infiltration were evaluated statistically. Immunoreactivities for COX-1 were heterogeneously observed in the medullary distal tubules and collecting ducts; no correlations with the severity of renal damage were detected. Immunoreactivities for COX-2 were heterogeneously observed in the macula densa (MD) regions. In dogs, the percentage of COX-2-positive MD was significantly correlated with the glomerular size. In cats, glomeruli with COX-2-positive MD had significantly higher sclerosis scores than those with COX-2-negative MD. In conclusion, renal COX-2 is induced in canine and feline CKD, especially in relation to the glomerular changes.     

Effects of supplementary probiotics to two different diets on dry matter intake, daily gain, digestibility, ruminal pH, and fecal microbial populations and metabolites in ewes

To study the effects of supplementary probiotics on dry matter intake (DMI), daily gain (DG), digestibility, ruminal pH, and fecal microbial populations and metabolites in ruminants, two reversal trials were conducted by using four Suffolk ewes fitted with rumen cannula. The ewes were fed with oat hay and with concentrate and oat hay in the ratio of 60 : 40 in experiments 1 and 2, respectively. The ewes in the treatment groups were supplemented with 10 g/day/head probiotics for 49 days. Fresh fecal samples were collected to measure microbial populations and metabolites. On days 43–47 total feces was collected to measure digestibility, and on the days 48 and 49 ruminal pH was measured. No significant difference of DMI, DG, dry matter digestibility, and ruminal pH was observed between the control and treatment groups. The probiotics treatment tended to increase crude fiber (P = 0.11) and organic cell wall digestibility (P = 0.18). In the final week, probiotics treatment significantly increased the fecal population of Bacilli (P < 0.05) and mold (P < 0.01) in experiment 1 and 2, respectively. No significant difference of fecal VFA and ammonia concentrations between the control and treatment groups was observed. The supplementary probiotics changed population of some microbial strains in the feces and possibly the large intestine of ewes.     

Effects of exposure to methylglyoxal on sperm motility and embryonic development after fertilization in mice

Methylglyoxal (MG) is a precursor for the generation of endogenous advanced glycation end-products involved in various diseases, including infertility. The present study evaluated the motility and developmental competence after in vitro fertilization of mouse sperm which were exposed to MG in the capacitation medium for 1.5 h. Sperm motility was analyzed using an SQA-V automated sperm quality analyzer. Intracellular reactive oxygen species (ROS), membrane integrity, mitochondrial membrane potential, and DNA damage were assessed using flow cytometry. The matured oocytes were inseminated with MG-exposed sperm, and subsequently, the fertilization and embryonic development in vitro were evaluated in vitro. The exposure of sperm to MG did not considerably affect the swim-up of sperm but resulted in a deteriorated sperm motility in a concentration-dependent manner, which was associated with a decreased mitochondrial activity. However, these effects was not accompanied by obvious ROS accumulation or DNA damage. Furthermore, MG diminished the fertilization rate and developmental competence, even after normal fertilization. Collectively, a short-term exposure to MG during sperm capacitation had a critical impact on sperm motility and subsequent embryonic development after fertilization. Considering that sperm would remain in vivo for up to 3 days until fertilization, our findings suggest that sperm can be affected by MG in the female reproductive organs, which may be associated with infertility.