Acid and alkaline phosphatase in bovine antral follicles

Acid and alkaline phosphatases were measured in the follicular fluid of 766 individual follicles from 96 cows. Follicles were obtained by bilateral ovariectomy or at slaughter from animals at various stages of the estrous cycle and pregnancy. Mean follicle size varied with the physiological state of the cow (P less than .0001). Acid phosphatase activity (U/microliters) varied inversely with follicle size (P less than .001) but not with stage of the estrous cycle or gestation. Total acid phosphatase activity per follicle increased with follicle size (P less than .05). Neither acid phosphatase nor alkaline phosphatase concentration was associated with atresia. Alkaline phosphatase activity (U/microliters) was greater in the smallest follicles (less than 50 microliters) than in other size groups (P less than .0001). Alkaline phosphatase activity (U/microliters) was greater (P less than .05) during the preovulatory phase of the estrous cycle than during other phases. A high concentration of follicular fluid phosphatases cannot be used as a marker for atresia but is characteristic of healthy small antral follicles.     

Effects of age, sex and breed on antipyrine disposition in calves

In domestic animals relatively little is known about the functions of hepatic microsomal enzymes and their role in biotransformation. In this study, antipyrine was used to assess microsomal oxidative function and particularly to determine the effect of age, sex and breed on drug metabolising enzymes. At birth, the elimination rate of antipyrine was very low as reflected by a half-life of 24 hours. The first two months of life were characterised by a steady decrease of antipyrine half-life values of three to four hours being reached at six months. The decrease observed during early life was not identical in the two breeds used in this experiment. By six months the Friesian calves eliminated antipyrine twice as fast as the Blue White Belgian (BWB) breed: 2.1 +/- 0.3 hours and 4.9 +/- 0.3 hours, respectively. The BWB breed is characterised by muscular hypertrophy and by a relative imbalance in muscle:body ratio. The apparent volume of distribution of antipyrine did not vary with age, sex and breed. No differences in antipyrine clearance were found between male and female calves.     

Effect of diet on Shiga toxin-producing Escherichia coli (STEC) growth and survival in rumen and abomasum fluids

The gastrointestinal tract of ruminants is the main reservoir for Shiga toxin-producing Escherichia coli (STEC) strains, potentially pathogenic for humans. We used for the first timerumen fluid in which no exogenous carbon source or other supplement was added to compare acid resistance and growth of STEC in physiological physico-chemical conditions. We showed that acidic conditions resulting from the combination of high volatile fatty acid concentration and moderately acidic pH did not alter the survival of STEC, and that human non-O157:H7 STEC isolates were able to persist in the rumen contents in spite of acid stress, low oxygen availability and nutrient deprivation, in the same manner as bovine STEC isolates do. Furthermore, our results support the hypothesis that a grain-rich diet may induce mechanisms of STEC acid resistance in the rumen that allow STEC survival in the abomasum.     

Motility of the rumen and abomasum during hypocalcaemia.

The relationship between plasma calcium level and rumen motility in cows and sheep and abomasal motility in cows was investigated by inducing hypocalcaemia in seven cows and five sheep by the infusion of Na2 EDTA over a period of approximately two hours. Rates and amplitudes of rumen and abomasal contractions were markedly reduced by the reduction of plasma calcium level to approximately 50% of normal. There were significant positive linear relationships (P less than 0.05) between rate and amplitude of rumen contractions in both sheep and cows over a plasma calcium range of 1-3 mmol/L. There was also a significant linear relationship (P less than 0.05) between plasma calcium and abomasal rate of contraction over the same range in cows, but the relationship with amplitude of abomasal contraction was not quite significant (P less than 0.1 greater than 0.05).     

Nitrogen balance in lambs fed a high-concentrate diet and infused with differing proportions of casein in the rumen and abomasum

Twenty-five wether lambs (34 +/- 0.9 kg) fitted with ruminal and abomasal infusion catheters were used in a completely randomized design to determine the effects of differing proportions of ruminal and abomasal casein infusion on N balance in lambs fed a high-concentrate diet (85% corn grain, 1.6% N; DM basis) for ad libitum intake. Wethers were infused with 0 (control) or 10.4 g/d of N from casein with ruminal:abomasal infusion ratios of 100:0, 67:33, 33:67, or 0:100% over a 14-d period. Feed, orts, feces, and urine were collected over the last 5 d. Total N intake and excretion were greater (P < 0.01) in lambs infused with casein than in controls; however, N retention did not differ in lambs infused with casein compared with controls, suggesting that N requirements were met without casein supplementation. Total N intake and total N excretion did not differ among casein infusion treatments. Urinary N excretion decreased linearly (P = 0.07) with decreasing ruminal infusion of casein. Site of casein infusion quadratically (P = 0.06) influenced N retained (g/d), with the greatest retention observed in the 33:67 ruminal:abomasal infusion treatment. Dry matter intake from feed decreased from 1,183 to 945 g/d (P = 0.02) in lambs infused with casein compared with controls, but apparently digested DM did not differ among treatments. These data indicate that decreasing the ruminal degradability of supplemental protein above that required to maximize N retention results in decreased urinary excretion of N without greatly affecting apparent diet digestion.     

Effects of seasonal variation,group size and sex on the activity budget and diet composition of the addax antelope

Behaviour and diet composition are critical elements in conservation biology within the scope of reintroduction programs. Here we focused on addax (Addax nasomaculatus), a Critically Endangered antelope species, in the Jbil National Park, Tunisia. In this study, we advanced the hypothesis that season, day period, sex and social structure have an effect on the activity budgets and diet composition of addax. Three groups were selected (large group, adult pair and solitary male). Resting, moving, grazing, vigilance and other behaviours were recorded during two seasons (dry and wet) and in the morning and the afternoon. In addition, faecal samples were collected. The results indicate that season and day period were the main factors affecting the activity budgets. The resting behaviour increased from the wet to the dry season, and from morning to afternoon. The grazing and moving behaviours increased during the wet season and decreased from morning to afternoon. Addax select a mixed diet composed of perennial and herbaceous plant species notably during the wet season. In addition, we observed that addax modify their behaviour according to the season and forage availability. This represents an adaptive strategy to survive in a desert climate with a stochastic low-resource environment and depending on ambient climatic conditions.     

Effects of breed and wintering diet on heifer postweaning growth and development

Fifteen spring-born Angus (AN) and 25 Brangus (BN) weanling heifers were used in a 2x5 factorial arrangement of treatments to evaluate the effects of breed and postweaning winter diet on heifer growth and development. Dietary treatments were warm-season perennial grass hay (H), ammoniated H (AH), H plus .68 kg/d cottonseed meal (HP), H plus .45 kg/d cottonseed meal plus 1.37 kg/d ground corn (HPE) and HPE plus 200 mg/d monensin (HPEM). Mean initial weight and age for the 107-d feed trial were 207 kg and 270 d. Brangus had .06 kg greater (P less than .05) ADG than AN during the trial. Although digestible DM intake (DDMI) relative to body weight was greater (P less than .10) for AN than for BN, ADG:DDMI was greater (P less than .05) for BN than for AN. Heifers fed H and AH lost weight, but heifers fed AH had 50% (P less than .05) less daily weight loss than those fed H. Daily gain increased (P less than .05) incrementally in response to sequential supplement additions of cottonseed meal (AH vs HP; -.10 vs .17 kg), ground corn (HP vs HPE; .17 vs .29 kg) and monensin (HPE vs HPEM; .29 vs .39 kg). Hay DM intake relative to body weight and DDMI were increased (P less than .01) by ammoniation. Intake did not differ between HPE and HPEM. Diet affected age at puberty (P less than .05), which decreased with increased dietary components. Weight differences among diet groups following the winter feed trial were largely eliminated prior to breeding. Nevertheless, H- and AH-fed heifers collectively weighed less (P less than .01) prior to breeding than did heifers of supplemented diet groups. Reproductive development tended to be adversely affected by weight loss during the postweaning period.     

Propagation of bovine coronavirus in clones of the Caco-2 cell line showing different levels of alkaline phosphatase activity

The aim of the present study was to determine whether bovine coronavirus (BCV) has the ability to initiate infection in a human colon carcinoma cell line, Caco‐2, that has been established to spontaneously differentiate after confluence. When Caco‐2 cells were infected with BCV, a titer of 5.5 × 10⁶ plaque‐forming units (p.f.u.)/mL was found in the culture supernatant at 5 days postinfection. Two clones, Caco‐2/CA1 and Caco‐2/CA2, were then isolated by monitoring alkaline phosphatase (ALP) and cell proliferation activities. The ALP activity level of CA1 cells was significantly higher than that of CA2 cells, while the level of cell proliferation activity of CA1 was significantly lower than that of CA2. When CA1 and CA2 cells were infected with BCV at confluence, virus hemagglutination (HA) was detected in the culture supernatant at 5 days postinfection for CA1 cells and at 8 days postinfection for CA2 cells. Thus, BCV propagation was substantially delayed in CA2 cells, suggesting that a cellular factor(s) that appears at the differentiation stage may control BCV propagation. BCV‐susceptible CA1 and CA2 cells showing different levels of ALP activity would be useful for further experiments to elucidate the mechanism of BCV propagation.     

Effects of papaverine on carbachol- and high K+-induced contraction in the bovine abomasum

The effects of papaverine on carbachol (CCh) -and high K⁺- induced contraction in the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM) -and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin or sodium nitroprusside inhibited CCh-induced contractions in a concentration-dependent manner in association with increases in the cAMP or cGMP contents, whereas papaverine increased cGMP contents only at 30 µM. Changes in the extracellular Ca²⁺ from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high K⁺-depolarized muscles, but papaverine-induced relaxation did not change. Futhermore, papaverine (30 µM) and NaCN (300 µM) decreased the creatine phosphate contents. These results suggest that the relaxing effects of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy metabolism.     

Effects of breed, sex, and halothane genotype on fatty acid composition of pork longissimus muscle

The objective of this study was to estimate the effects of breed, sex, and halothane genotype on fatty acid composition and several fatty acid indices of lipid extracted from porcine LM. Purebred Yorkshire (n = 436), Duroc (n = 353), Hampshire (n = 218), Spotted (n = 187), Chester White (n = 173), Poland China (n = 124), Berkshire (n = 256), and Landrace (n = 187) pigs (n = 1,934; 1,128 barrows and 806 gilts) from 1991, 1992, 1994, and 2001 National Barrow Show Sire Progeny Tests were used. Pigs were classified as the HAL-1843 normal (NN) genotype (n = 1,718) or the HAL-1843 carrier (Nn) genotype (n = 216). For statistical analysis, a mixed model was used that included fixed effects of breed, sex, halothane genotype, test, slaughter date, interaction of breed x sex, and random effects of sire and dam within breed. Breed significantly affected the concentration of individual fatty acids, total lipid content, and the values of several fatty acid indices of LM. Duroc pigs had the greatest (P < 0.01) content of total SFA. Total MUFA concentration in Poland China pigs was greater (P < 0.05) than in all other breeds except the Spotted (P > 0.05). The concentrations of total PUFA were greater (P < 0.01) in Hampshire, Landrace, and Yorkshire pigs compared with those of other breeds. Significant sex differences for individual fatty acids were detected. Compared with gilts, barrows had greater (P < 0.01) concentrations of SFA and MUFA but lower (P < 0.01) total PUFA. Halothane genotype was a significant source of variation for the percentages of some fatty acids. Pigs with the carrier (Nn) genotype had lower concentrations of SFA (P < 0.05) and MUFA (P < 0.01) but a greater concentration of PUFA (P < 0.01) compared with NN pigs. There were significant negative correlations between total lipid content and individual PUFA and significant positive correlations between lipid concentration and most individual SFA and MUFA. In conclusion, the results suggest that breed and sex are important sources of variation for fatty acid composition of LM.     

Histochemical activity of alkaline phosphatase and acid phosphatase in the epididymis of mature intact and androgen-deprived bulls

The histochemical localization of alkaline phosphatase (ALP) and acid phosphatase (ACP) was determined in regions I to VI of the epididymis in mature intact, orchidectomized, and orchidectomized testosterone-treated bulls. The intensity of ALP activity was essentially the same in all regions; however, its localization varied depending upon the region. Although the stereocilia and luminal border of epithelial cells were strongly-positive in regions I to III, these were negative in regions IV to VI. The basement membrane and circumtubular smooth muscle cells were strongly ALP reactive in all regions. Epithelial ALP activity was abolished completely by orchidectomy; however, it was restored to normal concentration by testosterone treatment implying its dependence on circulating testosterone. The ACP activity was present in the epithelial cells of all regions with the strongest activity in the supranuclear region. Similar to ALP, ACP activity was markedly reduced in the epithelial cells by orchidectomy. However, in contrast to ALP activity, lost ACP activity was only minimally increased by testosterone treatment in all regions, except in region VI where it was restored to a normal concentration. These observations imply that although the epithelial ACP activity of region VI was mainly under the influence of circulatory testosterone, there may be other factors such as luminal androgens, testicular fluid, and sperm that may be important in regulating the ACP activity of regions I to V of the epididymis. The importance of ALP and ACP in the epididymal epithelium was discussed.