Protein Sensors and Reactive Oxygen Species - Role A: Selenoproteins and Thioredoxin

Alexandra Fischer , ... Gerald Rimbach , in Methods in Enzymology, 2002

Development of Selenium Deficiency

Selenium and VE deficiency is readily produced by feeding the nutrition described higher up. Tabular array Ii xviii–22 shows various selenium and VE status parameters derived from animals after seven weeks on trial. These animals were further used for the assay of differently expressed mRNAs.

Tabular array II. Selenium and Vitamin Due east Concentrations, Glutathione Peroxidase, Glutathione Transferase, and Thioredoxin Reductase a

Group

Parameter		 I
(−Se, −VE)		 II
(−Se, +VE)		 3
(+Se, −VE)		 IV
(+Se, +VE)
Selenium (μthousand/kg FW) b 25.viii ± 3.7 31.eight ± 5.iii 892.3 ± 78.4 881.5 ± 41.4
α-Tocopherol (μyard/g FW) c 1.03 ± 0.2 29.six ± iii.eight one.15 ± 0.ii 32.ix ± 3.three
cGPx (mU/mg protein) d v.45 ± 0.96 10.nine ± 1.6 154.ii ± 11.ix 161.0 ± xv.2
TrxR (mU/mg protein) d 1.32 ± 0.17 1.16 ± 0.11 9.46 ± ane.05 9.25 ± 0.89
GST (mU/mg protein) d 209 ± sixteen.9 226 ± xvi.8 141 ± 10.8 162 ± 8.two

Abbreviations: VE, vitamin E; FW, fresh weight; cGPx, hepatic glutathione peroxidase; TrxR, thioredoxin reductase; GST, glutathione transferase.

a
In liver of growing rats fed diets containing different levels of VE and selenium (means ± SD).
b
Determination of selenium content of the liver was determined by hydride-generation atomic absorption spectrometry after microwave-supported wet digestion [B. Welz and M. Melcher, Anal. Chim. 165,131 (1984)].
c
Vitamin Eastward was analyzed by C18 reversed-phase HPLC (RP-HPLC) with fluorescence detection [J. Yard. Bieri, T. J. Tolliver, and G. Fifty. Catignani, Am. J. Clin. Nutr. 32, 2143 (1979)].
d
Assays performed on 10,000 one thousand supernatant fluid. The substrate used for the glutathione peroxidase assay was H2Otwo [R. A. Lawrence and R. F. Burk, Biochem. Biophys. Res. Commun. 71, 952 (1976)], that for the glutathione transferase assay was 1-chloro-2,4-dinitrobenzene [W. H. Habib and W. B. Jakob, Methods Enzymol. 77,398 (1981)], and that for the thioredoxin reductase assay was DTNB [S. Gromer, L. D. Arscott, C. H. Williams, Jr., R. H. Schirmer, and K. Becker, J. Biol. Chem. 273, 20096 (1998)].

Feed intake, live weight gain, and feed conversion efficiency were not significantly different in the four experimental groups. Hepatic glutathione peroxidase (cGPx) activity had fallen to 5% of command by seven weeks. Feeding selenium-deficient diets led furthermore to a significant decrease in hepatic selenium concentrations too as in hepatic thioredoxin reductase activities as compared with rats fed selenium-adequate diets. Glutathione transferases (GSTs), which are believed to compensate for the depletion of cGPx under selenium deficiency, were increased in the selenium-deficient animals. Rats fed diets enriched with VE had 30-fold college α-tocopherol liver concentrations every bit compared with nonsupplemented control animals.

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Anthelmintic resistance in ruminants: challenges and solutions

J. Charlier , ... L. Rinaldi , in Advances in Parasitology, 2022

3.1 Diagnostic markers of GIN infections

Current diagnostic markers of GIN infections and parasitic gastro-enteritis are broadly based on parasitological (east.m. FEC, peanut agglutinin egg staining, coproculture, Baermannisation), immunological (due east.k. parasite specific antibodies in serum or milk), pathophysiological (e.g. ocular mucous membrane colour measured by FAMACHA, packed cell volume, plasma/serum pepsinogen, diarrhoea/dag score) and performance based (e.m. alive weight gain, body status score) indicators (Fig. one; reviewed more than fully by Kenyon and Jackson, 2012).

Fig. 1

Fig. ane. Diagnostic markers and their use to assess helminth infection status and associated impacts in ruminants.

The usefulness of parasitological diagnostic tests as markers of parasite brunt varies due to the influences of factors such as prior exposure, fecundity of parasite species and variation in egg output associated with individual host animals (Gasbarre et al., 1996). The correlation betwixt FEC and worm burden is more often than not considered poor, specially in older cattle, simply parasitological indicators tin can be useful to confirm the presence/absenteeism of parasitic nematodes, provide information on parasite blazon present (nematodes, trematodes and cestodes), to assist in targeting anthelmintic administrations or to test the efficacy of products (for which, encounter Department "Diagnosis of AR" below). Carbohydrate specific binding of the lectin peanut agglutinin is used commercially for the detection and identification of H. contortus eggs. Unfortunately, examination of a broad range of other lectins has failed to identify whatever other with the required specificity to characterise additional nematode species (Umair et al., 2016).

Parasite-specific antibiotic detection can identify and categorise (sub-)clinical cases of nematode infection only measures mainly previous exposure rather than current infection. Moreover, test results can exist influenced by non-parasite related factors such every bit the age of the creature, milk yield or mastitis. The existing markers can also lack specificity (Charlier et al., 2014).

Pepsinogen assays prove good correlation with O. ostertagi brunt in start flavour grazing cattle but the correlation wanes in older grazing animals or post housing (Charlier et al., 2014). Reproducibility and harmonisation between labs are a farther factor that hampers the pepsinogen assay's reliability and routine uptake (Charlier et al., 2011). More recently leptin and ghrelin have been examined (Forbes et al., 2009), but the profile of leptin concentration in infected calves requires further validation earlier existence considered as a potential pathophysiological marker of parasite induced inappetence. The FAMACHA chart, which uses peri-ocular mucous membrane color to indicate depression packed red blood cell volume, i.eastward., anaemia, has been used globally to nifty success in the detection of Haemonchus infections in sheep and goats (Van Wyk and Bath, 2002) and more recently also for assessing Fasciola hepatica infections (Olah et al., 2015), while results in cattle are more than equivocal (Dorny et al., 2011; Grace et al., 2007).

The use of diarrhoea/dag score is past its nature useful at highlighting problems that issue in scouring in animals, but do not provide an indication of the cause, e.chiliad., pathogen versus physiological/nutritional. Additionally, diarrhoea is not a clinical sign in all GIN infections and may non be credible in sub-clinical or early stage infections. The correlation between worm burden and diarrhoea score has been poor in many studies (reviewed by Williams and Palmer, 2012). That said the diarrhoea/dag score has been used in conjunction with other indicators such as FAMACHA, body condition score, sub-mandibular oedema and nasal discharge as part of a Five Signal Check© for assessing overall full general health in sheep (Bath and Van Wyk, 2009).

The benefits and uses of product parameters such equally live weight proceeds or milk production have been successfully used for targeting anthelmintic administrations (Run across section below). As a whole, diagnosis of helminth infections combined with conclusion support tools could be considered of critical importance to counteract the spread of AR by targeting anthelmintic treatments to timings or animal groups at risk and where feasible even supporting individual-level treatment choices. Merging parasite diagnostics with animal performance metrics is attracting renewed enquiry focus in order to reduce the corporeality of anthelmintics used without jeopardising productive performance (Höglund et al., 2021).

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Prophylactic Assessment including Current and Emerging Issues in Toxicologic Pathology

Bryan L. Stegelmeier , ... Daniel Cook , in Haschek and Rousseaux'southward Handbook of Toxicologic Pathology (Tertiary Edition), 2013

three.ii Ryegrass Toxicity

This section will talk over two dissimilar syndromes, both involving ryegrass and both referred to colloquially equally "ryegrass toxicity." This common terminology can be confusing. Both syndromes involve species of Lolium (Poaceae), both are associated with symbiotic organisms, and both produce neurologic illness. However, that is where the similarities end, as they have unique causative agents, clinical development, pathogenesis, and outcome for livestock.

Perennial Ryegrass Staggers (PRGS)

PRGS is a reversible syndrome associated with ingestion of Lolium perenne by grazing livestock. First recognized in Australia, it has as well been described in North America. Poisoning has been described in sheep, cattle, horses, deer, camelids, and even a rhinoceros. Intoxication occurs when the grass is infected with the endophyte Neotyphodium lolii, which confers some degree of protection to the establish against insect herbivory. The endophyte produces a range of tremorgenic indole terpene alkaloids including lolitrem B and ergot alkaloids such as ergovaline (Figure 40.13). Ergovaline is also produced by N. coenophialum, which parasitizes alpine fescue (Festuca arundinacea) and causes vasoconstriction, hyperthermia, agalactia, and placental lesions.

Effigy forty.xiii. Structures of ergovaline (A) and lolitrem B (B).

As previously reviewed, PRGS occurs when livestock graze toxic pasture for about 7–14 days. Affected animals develop incoordination, staggering, head shaking, and plummet with associated muscular spasms of short elapsing. These clinical signs resolve within a couple of days if exposure is discontinued. Although morbidity is frequently loftier, few poisoned animals die; those that exercise and so generally die from starvation and aridity if they are unable to consume or beverage, or encounter some other mishap. Maybe the most significant impact of PRGS is due to the loss of contaminated forage, the cost of managing poisoned livestock, and subclinical production losses including reproductive deficits and reduced live-weight gains.

Ryegrass tremorgens are thought to impair inhibitory pathways in the nervous organization. They inhibit GABA receptors past binding near the chloride channel, and they may also modify other calcium and chloride channels. These changes exercise not produce feature lesions so the gross and histologic pathology will exist related to the effects of poisoning, such as emaciation and loss of torso condition and adipose stores. Some animals inconsistently may have more subtle changes of granular and Purkinje jail cell degeneration in the cerebellum. Though the pathogenesis is not withal understood, mute swans, whooper swans, and mixed breed domestic geese in a zoo enclosure adult photosensitization and subsequent dermatitis when ingesting perennial ryegrass. More work is needed to better ascertain this disease.

Annual Ryegrass Toxicity (ARGT)

ARGT is a distressing, often fatal neurologic disease of livestock in Australia, Southward Africa, and, rarely, North America. It is more often than not associated with annual ryegrass, also known equally Wimmera ryegrass (Lolium rigidum Gaud.). Annual ryegrasses are frequently used as livestock feed, but they tin can as well be an invasive weed when they develop herbicide resistance and spread in paddocks, and along fences and roadsides. The causative toxins, the corynetoxins, are produced when seed-head galls formed by the nematode Anguina funesta are infected by the bacterium Rathayibacter toxicus. The bacterial colonies produce the corynetoxins, a series of tunicaminyluracil glycolipid antibiotics (Figure 40.14), as the constitute begins to senesce. One of the principal biochemical furnishings of corynetoxins is the inhibition of Due north-acetylglucosamine-i-phosphate transferase (GPT) thereby preventing the associates of N-linked glycans and, hence, the formation of N-linked glycoproteins in the endoplasmic reticulum. Though the serum half-life for corynetoxin is a brusk 4 hours, there is evidence that clinical poisoning can be delayed and that poisoning may be cumulative. Cumulative experimental exposures separated by upwardly to ii months have been shown to exist toxic.

Effigy twoscore.14. Structures of corynetoxins. With a common N-acetylglucosaminyl-tunicaminyluracil core, the individual corynetoxins (about 12 congeners) simply differ in the length, degree of unsaturation or hydroxylation of the fat acid substituent (R).

Sheep are most often poisoned, though poisoning has also been reported in cattle and horses. Poisoned sheep will typically lag behind the flock, and when they are driven they may collapse, become recumbent, and develop convulsions. Less astringent clinical signs include muscle tremors, head nodding, opisthotonos, teeth grinding, nystagmus, and hypersalivation. Lethally intoxicated sheep volition be constitute in the paddock in lateral recumbency with mounds of soil at the feet resulting from the "paddling" convulsive action. In add-on to ARGT neurological affliction, poisoned animals develop clinical liver disease that is characterized by elevated serum liver enzymes and mild icterus.

At post-mortem examination, the liver is often enlarged, friable, and yellowish. The gall bladder is distended, and there are often petechial hemorrhages on the surface of the gall bladder and on the epicardium. Many tissues may have mild icterus. Despite the severe neurological signs, the most consequent histopathological lesions are hepatic. Affected hepatocytes are often swollen and vacuolated in increased numbers of inflammatory cells in the sinusoids (Figure 40.fifteen). Ultrastructurally, the cytoplasmic vacuolation is equanimous of dilated rough endoplasmic reticulum that often contains concentrically laminated concretions (Figure 40.xvi). The neurologic lesions are also non-specific every bit they are characterized by eosinophilic deposits of poly peptide-like fluid in the subarachnoid infinite and forth small vessels. It has been suggested that this is due to microvascular endothelial impairment. Other occasional neurologic lesions include loss of Purkinje cells and neuronal eosinophilia (possibly related to ischemic-hypoxic injury) of small foci of Purkinje and granular cells. Other reported non-lethal furnishings of the corynetoxins include testicular degeneration and ballgame. Although a vaccine and treatments accept been developed to protect or treat ARGT, none has yet found commercial application.

FIGURE 40.15. Liver of a sheep poisoned with annual ryegrass. Notice the swollen and vacuolated hepatocytes containing variable amounts of red staining lipid. Oil red O stain. Bar   =   50   μm.

 Photographs courtesy of Dr John Finne.

FIGURE 40.16. Electron photomicrograph of the liver of a sheep poisoned with almanac ryegrass. Notice the dilated endoplasmic reticulum with laminated concretions (~100   000× magnification).

 Photograph courtesey of Dr John Finnie.

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Beefiness

R.L. Joseph , in Encyclopedia of Food Sciences and Nutrition (2nd Edition), 2003

Typical Production Systems

Two-Year-Erstwhile Jump-Built-in Steer (Friesian/Friesian Cross)

This tightly managed semiintensive organization is suitable for north-west Europe. In February, male calves are bought and finished cattle are sold. In early Apr yearlings kickoff grazing 45% of the farm; 55% is closed for silage. By mid-May the calves are grazing ahead of the yearlings. In late May silage is cut, 45% of the farm is airtight for a second cut, taken in mid-July, then slurry is spread. The calves are castrated in late September. Finishing cattle are housed in mid-Oct, weanlings in early November.

Fifty cattle may be produced off 22   ha. The primary inputs per beast sold per yr are the 0.45   ha of productive grassland, to provide grazing and 10   t of silage; the fertilizers are 110   kg of nitrogen equivalent, 41   kg of potassium, and eleven   kg of phosphorus. Each beast receives 25   kg of reconstituted milk pulverisation, roughage, and concentrates ad lib. In the first winter the weanlings are fed silage and concentrates (150   kg). Yearlings receive 600   kg of concentrates during a 150-day finishing period.

Live-weight gains are from 0.half-dozen to 0.9   kg   day−1. Slaughter weight (Friesian) is about 600   kg, to requite a carcass of 320   kg, with about 220   kg of saleable lean beef, some 55   kg of bone and 45   kg of fat trim. Charolais × Friesian attain 680   kg, dressed 380   kg; giving 270   kg of lean meat, lx   kg of bone, and l   kg of fatty trim.

Suckler Beef

This is extensive and more mutual on marginal land. Calves suckle dams; a 'cow unit' consists of moo-cow, calf, and yearling. Cows are cantankerous-bred Hereford or Limousin on Friesian to give adequate milk with low maintenance requirements. Mating is to a third breed: Hereford, Aberdeen Angus, or Limousin for the first calving and large breeds, Charolais or Simmental for subsequently pregnancies.

Calving takes place in February to April. Calves grow rapidly on the milk, reaching about 300   kg at weaning in November. Each cow unit grazes 0.32   ha in April–June, with 0.45   ha reserved for silage. And then, until August, 0.48   ha is grazed; 0.29   ha is for silage. Thereafter, 0.77   ha is grazed until housing in Nov. Silage is cut, in late May and belatedly July, totaling 37   t   ha−1. Nearly 175–225   kg   ha−1 of nitrogenous fertilizer is applied yearly.

Housed yearlings accept silage ad lib with ane   kg per head per day of concentrates. Subsequently the second summertime on grass, the heifers are slaughtered, at 20 months, in November–December, finishing on silage and 3   kg   day−1 of concentrates. Slaughter at 500–600   kg gives carcasses of 260–330   kg. Steers are fed silage and 4   kg   day−one of concentrates to cease in early spring at 24 months, at a live weight of 620–680   kg and a carcass weight of 340–380   kg.

Bull Beef

In Europe, except the British Isles, virtually male person beef cattle are bulls. From nigh iv months they grow upwardly to eight% faster than steers, giving peradventure forty   kg more carcass. Bulls impale out at about 57% (dressed weight as per centum of carcass), 2% more comparable steers, with carcasses up to xv% heavier. Most 74% of a bull's carcass is lean meat, compared to 66% for steers. Bulls have a heavier forequarter, but a higher yield of high-price cuts.

Nearly bull beef is from the dairy herd, being Holstein/Friesian dual-purpose and dairy beef crosses. Calves bought at 1–3 weeks of age are reared to 100–150   kg on 25–fifty   kg of milk replacer, concentrates, and roughage. Slaughter at 12 months requires a high-cereal or -fodder beet diet, giving a daily gain of ane.1–1.4   kg and a carcass weight of 180–220   kg. The meat is very pale. Slaughter at 18–21 months requires maize silage with 15–xx% concentrates or beet pulp. Friesians reach 550   kg; dual-purpose and crosses may attain 600   kg.

In France, Spain, and Italia the suckler herd is an important source of bull beef. Veau de Lyons is Limousin, and at 12 months the slaughter weight is 450   kg; the meat is pale and non marbled. Slaughter at eighteen–21 months requires a nutrition like the dairy balderdash, just with more concentrates (25–30%). Carcass weights are 300–430   kg, depending on the region and breed.

Nearly all bulls are housed, usually loose in pens of 2–5   k2 per bull with up to 25   per pen. Farmers raising bulls must insure safety, with secure housing and fencing, warning notices, and careful work practice.

Bovine Spongiform Encephalopathy

Bovine spongiform encephalopathy (BSE) is a progressive, fatal neurological disease. Since 1986 some 26   000 cases have been recorded in the United kingdom, with sporadic cases in other countries. BSE presents, in adult dairy cows, as abnormalities of beliefs and gait. The causal agent was in meat and bone meal in concentrates fed to calves. In 1988, feeding ruminant protein to ruminants was banned, and notification and compulsory slaughter were introduced. (Run across Bovine Spongiform Encephalopathy (BSE).)

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Veterinary Control of Reproduction in Beef Herds

Neil Sargison , Colin Penny , in Veterinary Reproduction and Obstetrics (10th Edition), 2019

Applied Management of a Compact Mating Period

The achievement of a 94% pregnancy charge per unit later on a 63-twenty-four hour period mating period is dependent on the majority of heifers and cows cycling at the beginning of the mating period. Heifer direction, moo-cow nutrition and abstention of postparturient illness are critical in this regard.

The onset of puberty in heifers is controlled past body weight alee of age. Although in that location are differences betwixt breeds and management systems, more than than 90% of Bos taurus heifers will have displayed behavioural rut once they have reached 60% to 65% of their mature body weight (see Chapters 3 and 25). Fertility to the kickoff pubertal oestrus is lower than to subsequent oestrous events (Byerley et al. 1987); hence puberty should ideally be attained at least 1 month earlier commencing mating. Furthermore, heifers that are mated and conceive before reaching a disquisitional minimum weight will calve at lower body condition scores (BCS) and lighter weights than their contemporaries, thus with a loftier take chances of dystocia and failure to rebreed due to prolonged postpartum anoestrus. Strategies to hasten onset of puberty in beef heifers include treatment with progestogens or progesterone products and exposure to vasectomised bulls, but neither pick is commonly adopted in European beef herds and the response may be inconsistent (Diskin & Kenny 2014).

In leap calving herds, which source breeding replacements from homebred animals, or from other spring calving herds, practicalities dictate that heifers must calf for the beginning time at either 2 or 3 years former. Calving at 3 years old incurs higher maintenance costs of unproductive animals than calving at 2 years old and also reduces the potential productive lifespan and output of the female breeding herd. Conversely, calving at 2 years sometime provides a good footing for selecting replacement animals and potential for faster genetic gain. Hence well-nigh producers now aim to calve their heifers for the start time at 2 years old. This means that they must achieve 65% of their mature weight by a hateful age of 15 months. This equates to critical minimum mating weights of betwixt 325 kg and 420 kg for small Angus and large Continental European bred animals, depending on the characteristics of their brood; this requires mean live weight gains of between 0.65 kg/solar day and 0.84 kg/day from nascency. Achieving these targets is relatively straightforward for pocket-sized early maturing animals simply depends on high levels of supplementary feeding as part of a balanced ration for late maturing breeds. Overfeeding of early maturing breeds in particular, in an endeavour to attain critical minimum mating weights, compromises behavioural rut, conception rates, embryonic survival, and mammary gland development in fatty animals, and increases the risk of dystocia and postparturient infections. Control of infectious diseases, such as bovine respiratory disease, roundworms, and liver fluke, in growing heifers is critical to ensure growth targets are achieved.

Failure to accomplish disquisitional minimum weights at first mating of heifers results in high arid rates, whereas those that get pregnant calve at low weights and in poor body condition, with loftier levels of dystocia and postparturient disease. Subsequent barren rates of first calvers are high due to extended postpartum anoestrus in sparse animals, resulting in less than iii behavioural oestrous events during a compact three-cycle mating menstruation.

The postpartum anoestrous period after kickoff calving in heifers is about 20 days longer than that of cows in the aforementioned torso condition. This ways that if the heifers' 3-cycle mating period is the same as that of the cows, then during the subsequent year, offset calvers will only have two opportunities to prove behavioural oestrus; therefore, on average, 16% volition remain barren. Furthermore, those that become meaning will calve correspondingly later and remain late calving cows for the remainder of their reproductive lifespan, with a higher risk of non becoming pregnant before the finish of the mating period than in cows that calve early. Their calves that are born late in the calving period volition exist younger and lighter than those born earlier and therefore of lower sale value. In herds in which heifers are starting time calved at 3 years old, this problem is addressed by advancing the heifer mating flow by 3 weeks compared with that of the main moo-cow herd. All the same, in herds in which heifers are showtime calved at two years old, this strategy risks more than animals failing to reach their disquisitional weights at mating. A two-bike (6 weeks) heifer mating period, starting at the aforementioned time as the three-cycle mating menses for the main herd, offers a satisfactory compromise, allowing all of the heifers that calve to exist cycling at the beginning of the subsequent mating period. The compromise involves mating more heifers than are required, as perhaps just 84% will conceive, but potentially 71.5% (60% x 100/84) of those that become significant will calve during the first 3 weeks of the calving catamenia. In practice, if heifers take all reached their critical mating weights and are run with fully sound bulls, it is not unusual to achieve pregnancy rates of greater than 90% in a six-week heifer mating menses. The opportunities for alternative economically efficient direction of less than 2-yr-sometime barren maiden heifers are greater than those for older barren first or 2d calvers.

Heifer management dictates the reproductive performance of the whole herd and is cardinal to achieving reproductive targets. Heifers need to exist fed for maintenance plus 0.65 kg/day to 0.85 kg/day growth to ensure that they achieve critical minimum weights and are in good, but not excessively fat, torso condition at mating. Heifers must be mated with bulls that have been selected for ease of calving. The same airplane of nutrition must be maintained after mating to ensure that heifers calve in body status of 3.0 on a calibration of ane (very thin) to five (very fat), based primarily on palpation of the transverse processes of the lumbar vertebrae. This is relatively straightforward for spring calving heifers at pasture (Diskin & Kenny 2014) but requires a carefully balanced winter feeding ration in autumn calving herds. Higher BCS predisposes to dystocia, whereas lower scores event in extended postpartum anoestrous periods. After calving, heifers that were showtime mated at 15 months old benefit from separate, beneficial management until their second calving at iii years old. The differential illness and nutritional management of heifers and first calvers needs to exist planned and affords opportunities for veterinarian involvement in achieving beef suckler moo-cow reproductive targets. Prebreeding scoring of heifer reproductive tracts by palpation or transrectal ultrasonography of the uterus and ovaries tin can be helpful to identify individual animals with abnormal tracts, e.g., freemartins (see Chapter ix) and those that that are prepubertal and therefore probable to fail to become significant in a restricted mating period (Holm et al. 2015).

The postpartum anoestrous period of mature cows is determined by the nutritional demands of the previous pregnancy and lactation and is related to BCS at calving, plane of nutrition, and the calf suckling and maternal bond. Temporary calf isolation or restricted suckling from around 30 days postpartum may significantly shorten the time to get-go postpartum ovulation of beef cows (Stagg et al. 1998) but is impractical in most spring calving herds on pasture.

Cows calving in good BCS take the shortest postpartum anovulatory anoestrus. Low body condition (i.due east., < 2.5 on a v-indicate scale) leads to proportionally increased calving to conception intervals and later subsequent calving dates or to loftier barren rates. Increasing levels of feeding after calving has niggling beneficial consequence in cows that calve below target BCS; hence it is of import to manage pasture, fodder, and supplementary feeding throughout the year based on monitoring of BCSs and comparison with target values.

In order to minimise the duration of postpartum anoestrus, the target BCS at calving is betwixt 2.5 and three.5 on a 5-point scale. For bound calving beef suckler herds, in which the objective is to maximise the utilisation of herbage growth during lactation, this dictates a minimum target BCS of 2.0 at mating and iii.0 at weaning (Fig. 27.7). For autumn calving beef suckler herds, which depend on expensive forage and concentrate feeding during the winter to see the demands of lactation, minimum BCS targets of 3.0 at calving, two.5 at mating, and ane.5 at turnout in the spring are advisable, depending on the precise nature of the system (Lowman 1988).

In practice, a relatively inexpensive ration of ad lib harbinger and 2 kg of concentrate feed is sufficient for maintenance of a pregnant spring calving moo-cow over wintertime, provided that she enters winter in the right body condition. Management of herbage height controls nutrition during the summertime simply is less predictable than housed rations, commonly resulting in autumn calving cows being also fat at calving.

Pregnancy diagnosis and determination of fetal age by transrectal ultrasonography is useful in herds with a compact mating period to confirm that reproductive targets are met and instigate timely investigation if they are not. Practiced farm records of reproductive management are important in this regard, including: numbers of cows or heifers put to the bull; number of bulls used; dates that bulls were introduced and removed; number of cows or heifers diagnosed as pregnant; numbers of calves born live; first and last calving dates; number of cows or heifers calving in each three-week catamenia; and details of animal deaths or culling. Pregnancy diagnosis allows arid animals to be identified early and informed decisions to be made concerning what to do with them. This can be particularly helpful in the case of heifers, allowing nonpregnant animals to be removed and economically managed for finishing. Simple analysis and benchmarking of KPIs can exist undertaken using the same data discussed previously and allows ongoing monitoring of herd operation.

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Influence of host nutrition on the evolution and consequences of nematode parasitism in ruminants

Robert L Coop , Ilias Kyriazakis , in Trends in Parasitology, 2001

Production responses such as live-weight gain, wool growth and carcass quality have also been improved by protein supplementation of either housed animals infected daily with a 'trickle' nematode infection 17–nineteen or in naturally infected grazing livestock 20 . Positive effects of protein supplementation on resilience to nematode infection have likewise been recorded in goats 8 . Similar improvements in resilience of parasitized sheep have resulted from the supplementation of a basal diet with urea, a source of degradable nitrogen 21,22 . Although these responses to urea supplementation were less than those obtained with high-quality undegradable proteins, this arroyo is feasible in many tropical and subtropical areas where poor quality forages are generally available and the toll of high-quality protein supplements is prohibitive.

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Methods for assessing the brunt of parasitic zoonoses: echinococcosis and cysticercosis

Hélène Carabin , ... Paul R. Torgerson , in Trends in Parasitology, 2005

For CE, the largest costs might be the indirect costs, including reductions in live weight-gain, milk yield, fertility rates and value of wool or other products. Because some of these deficits are estimated to be ≥10%, they correspond the nigh serious CE-attributable losses to agronomics. These losses might exist difficult to gauge because of express numbers of controlled studies. Withal, available data (for review, see Ref. [21]) suggest that these losses are of import. In Jordan, indirect losses represent upwardly to 70% of total livestock losses that are attributable to CE [22]. AE seems to have little economical issue on livestock, although in that location are reports of infections in farm animals [23].

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The productivity effects of cattle tick (Boophilus microplus) infestation on cattle, with particular reference to Bos indicus cattle and their crosses

N.Due north. Jonsson , in Veterinary Parasitology, 2006

Little (1963) noted that the claret loss estimated to be caused by ticks would merely explicate about one quarter of the total loss in liveweight gain that he attributed to tick infestation of B. taurus cattle. Several researchers proposed suppression of appetite as a cause of lost product (Riek, 1957; O'Kelly and Seifert, 1970). The importance of reduced feed intake in tick-infested cattle was confirmed by a serial of studies by O'Kelly et al. (1971), Springell et al. (1971) and Seebeck et al. (1971). In this project, B. taurus (Hereford) steers were divided into three groups, each group including three matched steers. I of each triplet was infested with ticks, was fed advert lib and the amount eaten was measured. The second steer was not infested with ticks, only was fed exactly the same corporeality of the same feed equally the first steer. The third steer in each triplet was non infested with ticks and was fed the same ration equally the other steers, ad lib. This design was based on the premise that tick infestation is known to suppress ambition and that many metabolites would be affected by reduced feed intake. Then for whatsoever observed value, the specific or straight effect of ticks (non attributable to reduced feed intake) and the furnishings of reduced feed intake (anorectic outcome) were estimated as follows:

Combined upshot = ( value for tick-infested ad lib group ) − ( value for control group ) = Specific effect + anorectic consequence

Specific effect = ( value for tick-infested ad lib group ) − ( value for tick-gratuitous pair-fed group )

Anorectic issue = ( value for tick-free pair-fed grouping ) − ( value for control grouping )

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Bioenergy from permanent grassland – A review: 1. Biogas

A. Prochnow , ... P.J. Hobbs , in Bioresource Technology, 2009

In a grazing authorities the amount of nitrogen ingested past ruminants varies in a broad range, reaching the level of cutting systems at intensive grazing (Dahlin et al., 2005 ). Little of the dietary nitrogen is retained for liveweight gain or milk product ( Whitehead, 1990). The remainder is excreted, returning the nutrients immediately from the grazing animal to the pasture, where they are subject to remarkable losses by ammonia volatilization, conversion into nitrous oxide and nitrate leaching (Dahlin et al., 2005; Jarvis, 1993; Oenema et al., 1997; Whitehead, 1990). In extensive grazing all or virtually of the excreta assemble at pasture, while in intensive grazing regimes a larger part of the excreta has to be attributed to housing leading to nitrogen losses equally ammonia and nitrous oxide during slurry storage and following slurry awarding. In extensive grazing regimes a total of 12% of the nitrogen in above-ground biomass leaves the system, 5% in product and seven% as losses. Up to 88% of above-footing biomass nitrogen cycle within the system, mainly considering the biomass is not ingested by the animals and stays in the field. In intensive grazing systems 64% of the above-ground biomass nitrogen wheel within the system, while 21% leave with the product and 15% are lost.

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A critical review and meta-analysis of the magnitude of the effect of anthelmintic utilise on stocker calf production parameters in Northern U.s. States

P. Baltzell , ... A.Grand. O'Connor , in Veterinarian Parasitology, 2015

2.four Search

The search was designed with assistance from an information scientist with specialization in veterinary science. The CAB Abstracts search was conducted using the following search cord: "(Calf or calves or moo-cow* or cattle) AND (anthelmintic* OR deworm* OR fenbendazole OR oxfendazole OR albendazole OR ivermectin OR eprinomectin OR doramectin OR moxidectin OR levamisole) AND ("weight gain" or "body weight" or "liveweight gain" or growth or "weaning weight" or weight* or gain* or conception or pregnancy or functioning or "toll benefit assay" or economic science or "body condition" or liveweight or "feed conversion efficiency" OR "BCS" OR "trunk condition score" OR seasons OR "seasonal variation") AND (United states OR "United States" OR Connecticut OR Delaware OR Illinois OR Indiana OR Iowa OR Kansas OR Kentucky OR Maryland OR Massachusetts OR Michigan OR Minnesota OR Missouri OR Nebraska OR New Jersey OR New York OR North Dakota OR Ohio OR Pennsylvania OR Rhode Island OR South Dakota OR Vermont OR Virginia OR Due west Virginia OR Wisconsin). Limits included publication dates in or after 1970 and language express to English. Analogous search terms and limits were used in the remaining 3 databases.

The search in WorldCat (FirstSearch, 1970–2013) was [report and ("experiment station" or extension) and (cattle or beef) and (land proper name or university name)] using the country and institution names in Table 1. Only research reports indexed online were evaluated for eligibility. Titles from each online publication's table of contents were reviewed for every year indexed.

Table 1. Relevant states included in the review.

Connecticut Delaware Illinois Indiana Iowa
Kansas Kentucky Maryland Massachusetts Michigan
Minnesota Missouri Nebraska New Jersey New York
North Dakota Ohio Pennsylvania Rhode Isle Due south Dakota
Vermont Virginia West Virginia Wisconsin

Retrieved citations were imported into Endnote X6® (Thomson Reuters©, 2012) and duplicate citations were removed based on title and author. All citations from EndNote X6® were uploaded to Distiller SR® (Bear witness Partners, Canada), a systematic review software plan.

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