Effects of monensin on voluntary intake, eating and ruminating behavior and ruminal motility in heifers fed corn silage

Eating and ruminating behavior and associated ruminal motility of six heifers (1/4 Brahman X 1/4 Jersey X 1/2 Angus, 290 kg average weight) given ad libitum access to corn silage with or without 100 mg monensin X head-1 X d-1 were examined according to a two-period crossover design. There was no effect (P greater than .05) of monensin on level of intake, daily and unitary eating, ruminating and masticating times [min X g dry matter-1 X (kg body weight X 75)-1], duration or number of these activity periods, duration of main meals or latency time for onset of rumination following cessation of main eating activities. With the monensin treatment, daily numbers of normal boli and total boli were decreased (P less than .05) and mean duration of one rumination bolus cycle was longer (P less than .05). Analysis of covariance indicated relationships between intake of corn silage and duration of the main morning meal, duration or number of rumination boli and total ruminal contractions were affected (P less than .01) by monensin. Frequency and unitary number of strong cranio-dorsal ruminal contractions were similar for both treatments. During eating, number of contractions per minute was about twice (2.55/min) that during idling and rumination activity (1.43/min and 1.22/min, respectively). The unitary daily number of contractions was negatively (P less than .05) related to level of intake. Total daily ruminal contractions were slightly reduced (-3.96%, P greater than .05) by monensin. Results are interpreted to suggest that monensin indirectly affects rumination through a lowered motility and thereby affects turnover, gut fill and intake.     

Interrelationships among voluntary intake, eating and ruminating behavior and ruminal motility of heifers fed corn silage

Six heifers (1/4 Brahman X 1/4 Jersey X 1/2 Angus, 290 kg average weight) with ruminal, duodenal and ileal cannulae given ad libitum access to corn silage with or without 100 mg monensin X head-1 were used to determine interrelationships among behavior, ruminal motility and intake. Voluntary intake was positively related (P less than .001) to eating time, duration of the main morning meal and daily mastication time. Intake was negatively related to unitary times [min X g dry matter-1 X (kg body weight X 75)-1] of eating (P less than .05), rumination (P less than .001), mastication (P less than .001), unitary number of rumination boli (P less than .001), and latency time between termination of morning meal and onset of rumination (P less than .05). Both daily and unitary eating and ruminating time were positively related (P less than .001) to daily and unitary mastication time and unitary number of strong cranio-dorsal ruminal contractions. Positive relationships (P less than .01) were found between mean duration of daily meals, main evening meal and unitary eating time, and between mean duration of rumination periods and unitary ruminating time. Daily and unitary number of rumination boli and mean duration of one bolus were positively related (P less than .01) to unitary ruminating time. Interrelationships between intake, eating and ruminating activities and associated cranio-dorsal ruminal motility were all influenced (P less than .01) by individual heifer, which indicates potential in identifying individuals with better than average mastication behavior and ruminal motility.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of monensin on growth performance of beef heifers consuming warm-season perennial grass and supplemented with sugarcane molasses

Tropical Animal Health and Production - The objective of this study was to evaluate the effects of monensin on performance of beef heifers fed warm-season forages. Brangus heifers...     

Effects of monensin feeding on performance,nutrient utilisation and enteric methane production in growing buffalo heifers

Tropical Animal Health and Production - Murrah buffalo heifers (live weight 135?±?17 kg) were fed a total mixed ration without supplementation (CON), or supplemented with...     

中西结合制剂防治鸡柔嫩艾美耳球虫病试验

鸡球虫病是严重危害养鸡业的疾病之一,其中以柔嫩艾美耳球虫引起的疾病最为严重.目前防治球虫病的方法有免疫预防、化学药物防治和中草药防治.由于免疫预防存在免疫程序繁琐、免疫监测困难以及疫苗本身所存在的一些缺点,还不能在生产中被广泛的应用.现有的各种抗球虫药虽然见效快、疗效显著,但是在应用一段时间后都会导致虫体产生耐药性,并且会导致药物在畜产品中的残留、危害人类的健康.应用中草药防治毒副作用小,不易造成残留,但是发病时应用起效慢,治疗期长,不利于疾病的迅速控制 .本试验运用莫能菌素与中药联合应用的方法对柔嫩艾美耳球虫感染鸡进行疗效试验。     

Effects of time of day and monensin on the size distribution of particles in digestive tract sites of heifers fed corn silage

Effects of time of day and dietary monensin in the distribution of size of digesta particles in different digestive tract sites and their intersite relationships were examined in six heifers (290 kg BW) with ruminal, duodenal and ileal cannulas given ad libitum access to corn silage, with or without 100 mg monensin.head-1.d-1, in a two-period crossover design. Ingestive masticate and digesta of corn silage were collected via esophageal, ruminal or intestinal cannulas. The distribution of particulate matter retained on sieves with apertures larger than 20 microm was determined by wet-sieving. The cumulative distribution of particulate matter on a series of sieves was regressed on retaining sieve aperture to estimate the sieve aperture that would retain 50% weight of the particulate matter (median retaining aperture, MRA). The MRA of masticate was 6,494 microm. The MRA of digesta particles decreased (P less than .05) from ventral rumen (1,847 microm) to dorsal rumen (1,797 microm) to duodenum (346 microm), but increased to the rectum (359 microm). The MRA was lower (P = .044) for the monensin treatment only in feces. The MRA of particulate matter in the dorsal and ventral rumen, duodenum and rectum all changed (P less than .05) over 24 h. An inverse pattern between the MRA of ruminal and duodenal digesta occurred, presumably the result of a nycterohemeral pattern of eating and ruminating activity. Across sampling times, an inverse relationship existed between MRA of ventral rumen and duodenal digesta. This relationship suggests that a ruminal digesta raft composed of larger particles (immediately following major meals) is more effective than a raft of smaller particles (prior to such meals) in preventing flux of large particles to the duodenum.     

Consumption and ruminating behavior of sheep. 4. Experiments on young female sheep in different rearing intensities

In the framework of two rearing experiments with female merino meat sheep, measurings of the consumption and ruminating behaviour were carried out. Animals raised with a lot of roughage ruminated longer both in their lamb and young sheep periods. An increased quota of roughage in the ration increased both the ruminating time and the number of chewing moves and cycles significantly for young sheep. The dry matter intake capacity of animals raised with high quotas of roughage was by 14 and 8% resp. higher in the lamb period and by 26 and 18% resp. higher in the young sheep period. Rations with 24% chopped and dried green fodder and 11 ... 14% resp. crude fibre brought about a period of more than 6 hours ruminating and a minimum of 22,000 ruminating movements per day for lambs. Young sheep raised with high quotas of roughage showed an increased ruminating activity in subsequent periods of sole feeding with roughage.     

Hormonal calcium regulation and calcium setpoint in offspring of bitches with different calcium intakes during pregnancy

High maternal calcium (Ca) intake may lead to alterations in development and differentiation of fetal tissues and may result in altered 'programming' of Ca homeostasis, with eventual effects on Ca handling and skeletal development in the offspring during later life. In bitches fed a diet with a Ca intake three times above recommendations (3.27 g/100 g vs 1.14 g/100 g dry matter) during the second half of pregnancy, the plasma concentration of 1,25 dihydroxy cholecalciferol (1,25 (OH)₂ vit D) appeared to decrease, while plasma Ca, phosphorus (P), parathyroid hormone (PTH) and calcitonin (CT) concentrations remained unchanged. High maternal Ca intake did not result in altered basal or stimulated plasma concentrations of Ca, P, PTH, CT and 1,25 (OH)₂ vit D in the offspring (n = 7) when compared with pups from bitches fed a normal Ca diet during the entire pregnancy (controls, n = 7). The Ca setpoint for PTH secretion (^Ca S_for PTH) was therefore not different from controls. From this pilot study it may be concluded that excessive Ca intake during late pregnancy in the bitch has no deleterious effects on hormonal Ca homeostasis in the offspring.     

Quantitative unbiased estimates of endometrial gland surface area and volume in cycling cows and heifers

Entire reproductive tracts were removed from seven normal healthy heifers and qualitative unbiased estimates made of endometrial gland volume density and glandular surface density. After examining approximately 55 microscopic fields of endometrium from each tract, a mean glandular surface density value of 10.2 mm(2)/mm(3) (CE 3.1%) was obtained. The stereological method was then employed in optimising the design of the main study. The endometrial height was measured for 17 healthy cycling heifers and 19 similar cows. Subsequently, unbiased estimates were made of intercaruncular endometrial gland volume per unit surface for all cattle were investigated; differences between heifers and cows generally, and the possible effect of the follicular and luteal phases of the oestrous cycle were compared. The mean surface area of glands per unit area of endometrium at the intercaruncular site in heifers and cows was approximately 18 mm(2)/mm(2) in the follicular phase and 26 mm(2)/mm(2) in the luteal phase, figures similar to the gland area found in women. The intercaruncular gland volume increased significantly, by about 30% during the luteal phase of the bovine oestrous cycle in heifers, from 0.01 to 0.13 per mm(3). The differences in endometrial anatomy between site of sampling and either follicular or luteal phases of the oestrous cycle were always more significant in heifers than cows. The endometrial thickness in cows was always greater than for heifers, irrespective of the site of sampling. It was concluded that the intercaruncular endometrium of cattle was far more active physiologically than recognised previously.     

Ovine coccidiosis: comparison of the effects of monensin and aureomycin on lambs infected with coccidia

Lambs naturally infected with mixed species of Eimeria were fed monensin (30 mg/kg of feed) and aureomycin (10 mg/kg of feed) separately and in combination. An evaluation was made of the efficacy of the treatments in the suppression of oocyst production. Comparisons were made of the parasitic damage to the intestinal surface. Performance of the lambs was measured by weight gains and feed efficiency. Monensin given separately or in combination with aureomycin produced decreases in oocyst counts that were not significantly different from those in the lambs given only aureomycin. Body weight gains and feed efficiency were best in the aureomycin-treated group, and less so in the monensin-treated and the control groups. Animals fed the monensin-aureomycin combination had the poorest weight gains and feed efficiency. Scanning electron microscopy indicated that the groups fed monensin or aureomycin separately had morphologically normal intestinal surfaces. This was in contrast to the control group and the group fed the monensin-aureomycin combination, wherein there was disrupted intestinal surface morphology.     

Endocrine,metabolic and clinical effects of intravenous endotoxin injection after pre-treatment with meloxicam in heifers

Meloxicam (M), a non-steroid anti-inflammatory drug for use in animals, reduces prostaglandin (PG) synthesis by inhibiting cyclooxygenases-1 and -2. The aim of this study was to evaluate M's capability to prevent the inflammatory response elicited by endotoxin (ET). Furthermore, we wanted to evaluate a possible effect of M on delta13-reductase and 15-hydroxy prostanoate dehydrogenase, enzymes responsible for the initial metabolism of PGF2alpha. Four heifers acting as their own controls were used in the study. The heifers received an i.v. injection of either saline (S) or M (0.5 mg/kg) at 1.5 h before an i.v. injection of ET (50 ng/kg b.w. i.v.). The trial lasted 57 h after ET injection and blood samples were withdrawn for analyses of 15-ketodihydro-PGF2alpha (PG metabolite), cortisol, white blood cells (WBC), Fe, Zn and Ca. Clinical examinations were performed throughout the trial. In the S + ET trial, ET injection elicited a rapid increase of the PG metabolite, a prolonged cortisol release and reduced levels of WBC, Fe, Zn and Ca. General appearance and body temperature were affected. In the M + ET trial the PG release was totally abolished, the cortisol release was reduced and the clinical effect was milder, also effects on Fe, Zn and Ca were milder in the M + ET trial, but M did not prevent the pyrogenic effect of ET. In the next two trials, we injected PGF2alpha (500 ng/kg i.v.) with and without M pre-treatment. After PGF2alpha injection, plasma samples were collected for measurement of the PG metabolite. M had no effect on PGF2alpha metabolism. In conclusion, M effectively suppresses several of the inflammatory reactions seen after ET injections and has no major influence on the PGF2alpha metabolism.     

The effect of tiamulin administered by different routes and at different ages to turkeys receiving monensin in their feed

Healthy turkeys receiving 80 ppm monensin in their feed were injected at 26, 40 and 61 days of age with tiamulin at dosages of 12.5 and 25 mg/kg body weight. The aim of the study was to develop a regime for medicating with tiamulin turkeys receiving monensin in their feed, and which would circumvent the known toxicity created by the simultaneous administration of the two drugs. One injection of 12.5 mg/kg tiamulin up to the age of 61 days or 2 injections of 12.5 mg/kg tiamulin up to 40 days of age caused no mortality or adverse reaction.     

Consumption and ruminating behavior in sheep. 3. Experiments on infertile female sheep of different breeds with reference to feed type and feeding duration

Ewes of the breeds merino fattening sheep, Stavropol merino and fertility hybrid were studied as to their consumption and ruminating behaviour after receiving a pelleted straw-concentrate mixture, maize silage and wilted silaged grass. During the feeding periods of 2 X 45 min or 2 X 180 min/d unlimited rations were available to the animals. With 86 min/d the sheep used the short feeding period nearly completely for feed intake. In the longer feeding period the sheep consumed 18% more feed in 161 min/d, ate more slowly, however, and ruminated somewhat less. In comparison with the straw-concentrate mixture, the silage rations were ruminated for shorter periods and less effectively, the number of ruminating movements per day and cycle was reduced, the breaks between bites became longer. The wilted grass silage stimulated ruminating even less than chopped maize silage. There were significant differences between the breeds in the ruminating frequency, which affected the number of ruminating movements per day and cycle.     

Maternal breed of sire effects on postweaning performance of first-cross heifers and production characteristics of 2-year-old heifers.

Postweaning growth rates from weaning to 18 mo, fall condition score, pregnancy rates, and production to 2 yr of age were evaluated in a study of Angus (A)-, Pinzgauer (P)-, Red Poll (R)-, Simmental (S)-, and Tarentaise (T)-sired females from Hereford dams. First-cross heifers from the different sire breeds did not differ (P greater than .10) in initial weight. During a 140-d feed test, S gained 98.6 kg, exceeding (P less than .05) gains of P, 92.3; A, 91.4; and R, 87.3 kg but not T, 94.1 kg. Red Poll-sired heifers weighed less at the end of the 140-d test (P less than .05) than the other crosses, which did not significantly differ from each other. No breed of sire differences were found in gain from 140 d to fall weight. Simmental-sired heifers weighed more (P less than .05) than A- and R-sired heifers at 18 mo. Breed of sire and year interacted to affect pregnancy rate of the yearling heifers when mated to Shorthorn sires for 45 d. Percentage of dystocia varied from a low of 26.3 and 28.9% for T- and A-sired heifers, respectively, to 54.4 and 60.8% for P- and S-sired heifers, respectively (P less than .05). Age of dam of heifers affected (P less than .05) weight at the different period end points but not gains after weaning. Age of dam also affected incidence of dystocia. Two-year-old heifers from young dams had more dystocia than heifers from older dams. Shorthorn-sired calves from 2-yr-old heifers with different sire breeds differed in birth weight (P less than .05) but not survival from birth to weaning, ADG from birth to weaning, weaning age, or weaning condition score. Average 200-d weight of calves from P-, S- and T-sired heifers exceeded those from A- and R-sired heifers by 10.7 kg, or 5.7%.