Calving Charge per unit

The calving rate is divers every bit the number of calves really produced by a cow divided by the number of potential calves [xx].

From: Handbook of Fertility , 2015

MATING MANGEMENT | Fertility

G.E. Mann , in Encyclopedia of Dairy Sciences, 2002

What is Happening to Dairy Cow Fertility

By combining a number of reports of calving rate from both the U.k. and the United States, obtained over the terminal 50 years, it tin conspicuously be seen that the calving rate has been steadily declining ( Figure 1 ). By fitting a line through these estimates, we tin come across that the situation is becoming critical; hereafter predictions paint a grim picture. Over the last l years, the rate of decline appears to exist in the club of 0.half-dozen% per annum. This decline has been linked to a number of changes within the dairy industry, including increased milk yield, increased herd size, change in breed construction and changes in management strategy.

Figure 1. Pass up in pregnancy rate over the past 50 years and predictions for the future. The fitted line demonstrates a decline in pregnancy charge per unit of 0.half dozen% per annum. Each signal represents an approximate of pregnancy charge per unit based on lactating dairy cows in the U.k. or United States. (Data from Sreenan JM and Diskin MG (1983) Veterinary Record 112: 517–521; Esslemont RJ (1992) Veterinary Record 131: 209–212; Esslemont RJ and Kossaibati MA (1996) Proceedings of the Nottingham Cattle Fertility Conference; Gordon I (1996) Controlled Reproduction in Cattle and Buffaloes. Wallingford: CAB International; Pursley JR et al. (1997) Journal of Dairy Science 80: 295–300; Butler WR (1998) Journal of Dairy Science 81: 2533–2539; Imperial MD et al. (2000) Animal Science lxx: 487–501.)

Since the advent of artificial insemination and the associated increase in the intensity of genetic selection, there has been a dramatic increase in milk yield. This increment in milk yield, with the associated metabolic demands that it places on the cow, has often been put forward as the cause of this decline in fertility, though the mechanism underlying any relationship has non been established. It may result from a direct genetic selection for lower fertility, maybe through traits linked to milk yield. However, over the same period the dramatic refuse in the fertility of lactating dairy cows has not been accompanied by a similar decline in the fertility of first-service heifers, which has remained relatively abiding. This suggests that in that location may be no direct genetic trend confronting fertility, rather a subtract in the cows' power to cope with this increased yield or, conversely, increasing difficulties in meeting the dietary and direction requirements of these high-yielding cows.

Numerous attempts take been made to blame the introduction of Holstein genes on the pass up in fertility in countries making all-encompassing use of Holstein semen. However, as high milk yield has been linked to poor fertility, information technology is hard to dissect out the effects of 'Holstein genes' from the increased metabolic load associated with the increased milk yields observed in Holstein cattle.

Increased herd size almost certainly has a major role to play in this fertility decline with its associated reduction in staff hours per fauna spent on, for example, rut detection. Every bit herd size continues to increase, this particular problem tin only get worse, unless new technologies for heat detection are practical (see MATING MANAGEMENT | Detection of Oestrus) or more employ is made of oestrus/ovulation synchronization programmes to bypass the need for oestrus detection (see OESTRUS CYCLES, CONTROL | Synchronization of Oestrus).

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Sometime and New World Camelids

Gayle D. Hallowell , in Veterinary Reproduction and Obstetrics (Tenth Edition), 2019

Infertility in Camels

The reproductive rate in camelids is moderate to depression (Gordon 1997 ). This was shown by studies of 30 herds in Tunisia, where there was a calving rate of twoscore% and a bloodshed rate between birth and 1 twelvemonth of 17% ( Djellouli & Saint-Martin 1992). However, anecdotal evidence from some Bedouins is that, for every 100 Arabian camels mated, lxxx to 90 produce calves. Nearly 1% of the camels are sterile. Their fertility is maintained throughout life, normally breeding in alternate years; a female tin over her breeding life yield a full of 12 offspring, although an average of eight is more than likely. One mating per oestrus is usual, and it is possible for a male person to serve five or six females in a day. It is said that ane male is sufficient for 200 females with controlled convenance, but a much smaller number is customary. Both male person and female factors are responsible for camel subfertility.

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Embryo Transfer and Other Assisted Reproductive Technologies

Henrik Callesen , ... Torben Greve , in Veterinary Reproduction and Obstetrics (Tenth Edition), 2019

Twinning

In sure beefiness cattle breeds, twinning may be an attractive prospect. With the transfer of two in vivo derived or in vitro produced embryos (IVP) to each recipient, it is possible to obtain a calving rate for each embryo that is greater than 100%. Embryos should be placed in both horns, as this will ameliorate the number of fetuses that survive ( Sreenan & Beehan 1976). It was speculated that the technology would gain a broader application with the use of IVP embryos, which tin exist produced at a lower price (Lu & Polge 1992), just information technology has not been used widely in practice, as information technology requires expensive equipment and avant-garde training; in some countries, it is even prohibited past law.

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Artificial Insemination

Timothy J. Parkinson , Jane M. Morrell , in Veterinary Reproduction and Obstetrics (10th Edition), 2019

Management of Insemination

Inseminations may be performed past technicians employed by AI organisations but increasingly is being done by farm staff.

Fertility after AI is generally monitored past recording the proportion of cows that render to oestrus subsequently the initial service. The proportion of females that do not return to oestrus is sufficiently closely related to the proportion that actually accept go and remained significant to be a useful monitor of fertility (reviewed by Salisbury et al. 1978 ). The figure thus obtained, the non-return rate (NRR), which is an overestimate of calving charge per unit, is generally in a fixed ratio to the calving charge per unit depending on the interval after initial insemination at which information technology is calculated. The NRR is useful for observing trends in performance and for identifying beneath average functioning. The NRR can be used by AI centres to monitor both the fertility of their bulls and the results obtained by their technicians. Technicians whose performance is beneath average are normally required to undergo a period of retraining and/or limited licensure until their results better. Bulls that produce consistently low figures are removed from the AI service. Some centres make use of an 'adjusted NRR', whereby a number of factors that may affect fertility, such as moo-cow or heifer, age of female, number of parities, location of farm, and identity of inseminator, are taken into account to create a 'fertility index score'. This score is believed to give a more accurate moving picture of a bull's fertility than using the unadjusted NRR.

Farm staff can be trained to inseminate cattle, with many countries allowing 'farmer-inseminators' to breed their own cattle. There are two potential advantages that persuade farmers to undertake their own inseminations: first, the avoidance of the costs associated with having an AI centre technician perform the insemination; and, second, the hope that improved timing of insemination to ovulation will raise conception rates. Morton (2000) undertook a widespread survey of the results achieved past farmer-inseminators in comparison to AI centre technicians. Overall, farmer-inseminators achieved a iii% lower conception charge per unit than centre technicians (45% vs 48%). Notwithstanding, although 13% of farmer-inseminators achieved conception rates that were more 5% higher than heart technicians, 45% had results that were more than than v% worse, and 12% had results that were more than than xv% worse than middle technicians.

In exercise, farmer-inseminators who are well trained, motivated, take enough time to perform inseminations, and have reasonably large herds tend to achieve good results, whereas those for whom it is 'some other job' or who do not have the opportunity to develop a good insemination technique practise not. Poor insemination technique can be associated with disastrously poor pregnancy rates.

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Volume 1

D.C. Wathes , K.G. Diskin , in Encyclopedia of Dairy Sciences (Third Edition), 2016

Conception Charge per unit Post-obit Service

The conception charge per unit is the third major gene affecting reproductive efficiency. The primary factors implicated in causing conception failure or embryo death are normally categorized as those of genetic, physiological, endocrine, and environmental origin.

Fertilization Rate and Early Embryo Loss Rates

Based on published data, there is little evidence to propose that fertilization rates are likely to be different in the modern high-producing cows as compared with lower-producing cows or heifers, particularly under temperate climatic weather. When adequate numbers of spermatozoa are used from bulls of loftier fertility and cows are correctly inseminated during or shortly later the end of standing estrus, fertilization rates approaching 90% should exist expected. Fertilization rate is apparently similar in high- and moderate-producing cows and is unlikely to be affected by whether the cows are on pasture or loftier-input total mixed ration (TMR) diets. The boilerplate calving rate to a single service is, nevertheless, significantly lower in high-producing cows than in either low-producing cows or heifers. An embryonic and fetal mortality rate (excluding fertilization failure) of ∼40% is calculated for moderate-producing cows based on a fertilization rate of ninety% and an average calving charge per unit of ∼55%, with an estimated lxx–eighty% of the loss existence sustained between days viii and 16 afterward insemination. The comparative figure for high-producing dairy cows, based on a fertilization rate of 90% and a calving charge per unit of 40%, would be 56% ( Table 2).

Table 2. Summary of pregnancy losses from insemination until calving

Stage % Lost Reason No. still pregnant
Insemination of dam 100
Fertilization of oocyte 10% Fertilization failure, incorrect time AI 90
Meaning at 24   days post-AI 40% Early embryo mortality 54
Significant at 60   days post-AI 7–xx% Belatedly embryo mortality 43–50
Pregnant in tardily gestation v% Abortion forty–48

Pattern of Embryo and Fetal Losses

Based on published literature, there is some evidence that the design of early embryo decease in the modern high-producing cow may exist different from that observed in heifers and lower yielding dairy cows. The extent of early embryo loss appears to be larger, with a much higher proportion of the embryos dying before day 7 following insemination. Because fertilization rates exceed ninety%, conception failure is almost synonymous with embryo and fetal loss.

With the advent of ultrasound scanning, it has been comparatively easier to establish accurately the extent and timing of late embryo/fetal mortality. A recent Irish study quantified the pattern of embryo/fetal losses from days 28 to 84 of gestation in 1046 lactating dairy cows and 162 dairy heifers managed on pasture-based systems of milk product. The overall embryo/fetal loss rates over this menses were similar for cows (vii.2%) producing on average 7247   kg of milk and heifers (vi.1%), and the pattern of loss over this catamenia was also similar for cows and heifers. Almost half (47.5%) of the total recorded loss occurred between days 28 and 42 of gestation. There was no pregnant association between the level of milk production or milk energy output measured up to 24-hour interval 120 of lactation, milk fat concentration, milk protein concentration, or milk lactose concentration, and the late embryo/fetal loss rate. The extent and pattern of embryo/fetal losses were not related to either the cow'southward or the cow sire'south genetic merit. These figures are much lower than that those reported from several other recent studies which have indicated late embryo loss rates of effectually xx%. The reported differences may exist related to the college level of milk production in some other countries. There is as well bear witness to associate later losses with episodes of mastitis or with high ambience temperature. Although late embryo losses are numerically much smaller than early on ones, they have a major bear upon on the fate of the animals concerned. Information technology is frequently too long after calving to rebreed the cows which echo, so many are culled, causing serious economic losses to producers.

Some additional losses occur later on in pregnancy. The average abortion rate in cattle is effectually 5%. This is often associated with specific diseases, although in over 50% of cases submitted for diagnosis no infectious agents are identified. Of those where a diagnosis is possible, up to one-half are desultory cases associated with opportunistic bacterial infections (e.thousand., Arcanobacterium pyogenes). Other possible causes are zoonotic leaner (east.m., Leptospira spp.), fungal infections (e.g., Aspergillus fumigatus), protozoa (east.k., Neospora caninum), and viral infections (e.g., bovine viral diarrhea virus, infectious bovine rhinotracheitis). Some of these diseases remain quite widespread in dairy cow populations.

Once estrous cycles have resumed postcalving, so it is the product of rut detection efficiency and formulation rate that determines the overall herd reproductive efficiency (Tabular array 3). The clear message is that depression conception rates can to some extent exist compensated for by improving heat detection efficiency. Improving heat detection efficiency by 12–15% has the equivalent effect of increasing formulation rate by 10%. Practical and easily adoptable technologies to do this were outlined above.

Table three. The issue of different rut detection (submission) and conception rates on the percentage of the herd that is pregnant at 90   days later on onset of breeding flavour

Conception rate (%)
60 50 40 30
Heat detection rate
(%)		 xc 96 91 83 71
70 89 82 73 61
50 76 68 59 48
40 67 59 50 forty

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Effects of Environment on Bovine Reproduction

PETER JAMES HANSEN , in Current Therapy in Large Animal Theriogenology (2nd Edition), 2007

Genetic Comeback

Distinct breed differences are recognized in effects of heat stress on reproductive function, with reproductive function in B. indicus and other thermotolerant breeds being less afflicted by heat stress than in breeds that evolved in Northern climates. Differences between B. taurus and B. indicus in thermotolerance are due largely to differences in thermoregulation. In one study, the alter in calving rate for each unit of measurement increment in rectal temperature was the aforementioned for B. taurus and B. indicus × B. taurus crossbreds. Some evidence, still, indicates that breed differences in thermotolerance also exist at the cellular level. Almost strikingly, Brahman embryos were institute to be more resistant to culture at elevated temperatures than Holstein or Angus embryos. This finding raises the possibility that information technology may be possible to place genes that confer cellular thermotolerance and transfer these to breeds of cattle susceptible to oestrus stress so equally to reduce infertility during heat stress.

The relative advantages and disadvantages of crossbreeding between thermotolerant and nontolerant breeds depends on a host of conditions and is beyond the scope of this chapter. Genetic selection to increment thermotolerance also tin be skilful but may have undesirable consequences. One trait that contributes to thermotolerance is low metabolic heat product. Therefore, option for thermotolerance could indirectly pb to selection for reduced feed intake, milk production, or growth. It as well is possible to select for specific traits conferring resistance to heat stress (including coat color and the slick gene controlling hair length in cattle), merely potential advantages of such an arroyo are diminished past reduced selection for traits of economic importance such as milk product. A better approach may be to select for product in the hot climate itself; data from beef cattle suggest that this arroyo results in indirect pick for thermotolerance.

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Reproductive Management of Bison

JERRY C. HAIGH , JOHN GRINDE , in Current Therapy in Large Animal Theriogenology (Second Edition), 2007

PRODUCTIVITY

The calving rate and number of calves per developed cow bison vary widely according to management system, specially nutritional status.

In some gratis-ranging herds the productivity is much less than in managed operations. For instance, five parameters of reproductive biology of the gratis-ranging herds in Yellowstone National Park were examined by Kirkpatrick and associates. 7 They establish that lactating cows younger than 5 years of age did non conceive, a fact caused past ovulation failure, and that range condition had an outcome upon conceptions in cows iv years onetime or younger. The pregnancy rates reported for cows of this age would not be acceptable in commercial herds.

Even so, calving rates for bison in the National Bison Range, Montana, were between 78% and 100%. 8 Kirkpatrick and assembly 7 considered that the iii factors of environmental conditions, age, and lactational country influence the overall reproductive operation of the bison in their report, and it is likely that these factors play a role in any mammalian population.

Successful bison managers command parasite loads in their herds either through skillful pasture direction, or the utilise of anthelmintics at strategic points in the calendar. nine Of item concern are the tummy worms of the family Ostertaginae, which have been shown to cause death in both wintertime and spring, mainly through type II ostertagiasis, or in summer past causing decrepitude and reduced productivity, including reproductive failure. 10

Good pasture management is essential for the success of breeding programs in bison operations. Information technology is mutual practice to "flush" bison earlier the onset of the rut, and ensure that cows enter the convenance flavour in good trunk status. seven At this fourth dimension almost ranched animals are also feeding calves, and on well-managed properties an objective is to reach as close as possible to a 100% conception rate, fifty-fifty in lactating animals.

Practiced nutritional management is also essential in the spring months. Dystocia is reported by bison ranchers, and there is niggling doubt that overfat cows accept an increased risk of dystocia, although this has not been critically tested. 9

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Reproduction, Events and Management | Mating Direction: Fertility

Yard.G. Diskin , in Encyclopedia of Dairy Sciences (2nd Edition), 2011

Conception Charge per unit

This is the 3rd major factor affecting reproductive efficiency. The main factors implicated in causing conception failure or embryo decease are normally categorized as those of genetic, physiological, endocrine, and ecology origin.

Fertilization rate and early embryo loss rates in Cattle

Based on published data, at that place is little prove to suggest that fertilization rates are likely to exist different in the modern high-producing cow as compared with lower-producing cows or heifers peculiarly under temperate climatic weather condition. When adequate numbers of spermatozoa are used from bulls of high fertility and cows are correctly inseminated during or shortly afterward the end of continuing estrus, fertilization rates budgeted 90% should exist expected. Although fertilization rate is evidently like in high- and moderate-producing cows and is unlikely to be affected past whether the cows are on pasture or high-input full mixed ration (TMR) diets, the average calving rate to a single service, nevertheless, is significantly lower in high-producing cows than in either depression-producing cows or heifers. An embryonic and fetal mortality charge per unit (excluding fertilization failure) of ∼xl% is calculated for moderate-producing cows based on a fertilization rate of 90% and an average calving rate of ∼55%, with an estimated 70–80% of the loss being sustained between day 8 and 16 later on insemination. The comparative figure for high-producing dairy cows, based on a fertilization rate of 90% and a calving rate of 40%, would exist 56%.

Pattern of early embryo loss

Based on published literature, there is some evidence that the pattern of early embryo expiry in the modern high-producing cow may be different from that observed in heifers and lower-yielding dairy cows. The extent of early on embryo loss appears to exist larger in the modernistic high-producing dairy cows, with a much college proportion of the embryos dying before twenty-four hour period 7 following insemination. The expected event of 100 inseminations of British-Friesian and Holstein-Friesian cows is summarized in Figure 2 . Because fertilization charge per unit is close to 100%, formulation failure is most synonymous with embryo and fetal loss.

Effigy 2. Reproductive outcomes in British-Friesian vs. Holstein-Friesian cows.

With the appearance of ultrasound scanning, it has been comparatively easier to accurately establish the extent and timing of late embryo/fetal bloodshed. A contempo study past the Teagasc laboratory, Galway, Ireland, quantified the extent and pattern of embryo/fetal loss from days 28 to 84 of gestation in 1046 lactating dairy cows and 162 dairy heifers managed on pasture-based systems of milk production. The overall embryo/fetal loss rates betwixt days 28 and 84 of gestation were similar for cows (7.2%) producing on average 7247   kg of milk and heifers (vi.1%), and the blueprint of loss over this period was also similar for cows and heifers. Virtually half (47.five%) of the full recorded loss occurred between days 28 and 42 of gestation. At that place was no meaning clan betwixt the level of milk production or milk energy output measured up to day 120 of lactation, milk fat concentration, milk protein concentration, or milk lactose concentration and the late embryo/fetal loss rate. The extent and pattern of embryo/fetal loss were not related to either the cow'south or the cow sire'south genetic merit. The author does acknowledge that the extent of late embryo/fetal mortality recorded in the Irish pasture-based studies is much lower than that reported for some US-based studies. Notwithstanding, a clear caption for the reported differences is not credible simply may be related to the level of milk production, ambience temperature, and/or the breeding of cows following various Ovsynch-based protocols in the United states.

Progesterone during the cycle immediately prior to insemination and embryo survival rate

Data from a recent written report conducted past the Teagasc laboratory, Galway, Ireland, clearly show that there is a positive linear association between the concentrations of progesterone on the day of PGF-2α-induced luteolysis and the subsequent embryo survival charge per unit ( Figure three).

Effigy iii. Relationship between plasma concentrations of progesterone on solar day of induced luteolysis and subsequent embryo survival rate.

Post-obit a literature review, it was concluded that the most probable effect of depression concentrations of progesterone in the cycle preceding oestrus on subsequent embryo survival rate is preterm oocyte maturation, which subsequently compromises its ability to continue normal embryo development after its fertilization.

Post insemination progesterone and embryo survival charge per unit

Contempo studies by the Teagasc laboratory, Galway, Republic of ireland, that accept employed logistic regression techniques to model the relationship between the binomially distributed dependent variable (conception/embryo survival rate; yeah or no) and the continuously distributed independent variable (progesterone) accept established a relationship between circulating progesterone and embryo survival rate. In a report past Stronge et al. ( Figure four) in that location was a positive linear relationship between milk concentrations of progesterone on days 5, half-dozen, and 7 post insemination and the embryo survival charge per unit, and a quadratic relationship betwixt the rate of modify in concentrations of progesterone between days 4 and 7 and the embryo survival rate. Further assay of this data ready reveals that 75, 72, and 56% of dairy cows had concentrations of progesterone that were optimal for formulation on days 5, 6, and vii mail insemination, respectively. In that location is evidence that progesterone supplementation of dairy cows having low endogenous concentrations of progesterone, and consequently at risk of suffering embryo death, volition have improved embryo survival rates.

Effigy 4. Relationship betwixt milk concentrations of progesterone on day 5, 6, and seven afterwards AI and subsequent embryo survival rate in lactating dairy cows. Reproduced with permission from Stronge AJH, Sreenan JM, Diskin MG, Mee JF, Kenny DA, and Morris DG (2005) Post-insemination milk progesterone concentration and embryo survival in dairy cows. Theriogenology 64: 1212–1224.

A series of studies with dairy cows at the University of Wisconsin take shown that peripheral concentrations of both progesterone and estradiol are lowered by increased airplane of feed intake owing to increased metabolic clearance rate (MCR) of the steroids, which is related to liver blood menstruum (LBF). From these studies, it would appear that LBF is elevated in high-producing lactating dairy cows and this in turn would issue in a lowering of peripheral concentrations of progesterone thus increasing the risk of embryo death. The reduced progesterone upshot may retard the growth and evolution rate of the embryo by hampering uterine secretion of proteins and growth factors essential for early embryo development. Interferon-τ, the embryonic signal required for the maintenance of the corpus luteum and the estalishment of pregnancy, has also been shown to be positively correlated with progesterone. Uterine expression of the mRNA for progesterone receptor and estradiol receptor and of the retinol-binding protein mRNA are all sensitive to changes in peripheral concentrations of progesterone during the first week subsequently AI.

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Agricultural and Related Biotechnologies

P. Madan , in Comprehensive Biotechnology (Second Edition), 2011

iv.38.2 Survival of the Early Embryo

The importance of this critical period of embryo evolution is highlighted by the loftier incidence of embryo loss during early stages of embryogenesis. Early on embryonic bloodshed (EEM) has been suggested as a central determinant of the reproductive efficiency in cattle as it leads to loss of a big number of potential calves, retarded genetic progress, and meaning loss of money and time in rebreeding cows, thereby making embryo survival of economic as well every bit cardinal importance. This is evident from the fact that fertilization rates for cows are generally shut to xc% [v] , only the average calving rate to a single insemination is only most 40–fifty% [6], suggesting that embryonic and fetal deaths account for almost of the reproductive wastage following unmarried breeding. EEM happening within 3 weeks of insemination has been estimated to be around 30–40% in cattle [vii–9] and can business relationship for upward to 75–eighty% of all embryonic and fetal deaths, which results in substantial loss of production. In a recent study, embryo survival rates on twenty-four hour period 14, xxx, and at term have been found to be almost similar at 68%, 76%, and 71.eight%, respectively, indicating that most embryo losses occur during the first 2 weeks of bovine evolution [10]. Furthermore, in cattle, embryos produced in vitro showroom morphological, biochemical, and metabolic differences compared with their in vivo counterparts [iii, 11–thirteen]. Loftier EEM has substantially hampered the field awarding of in vitro embryo product in bovine leading to the practice of transferring ii embryos or more to achieve successful pregnancy [fourteen–16].

Embryonic loss is even college in humans, where 62% of the pregnancies diagnosed by increases in human chorionic gonadotropin (hCG) do non come to term [17] and around 20% of these neglect even before the pregnancy is detected clinically [xviii, 19]. There is evidence to support a similarity in some aspects of embryonic loss in humans and ruminants [6]. For case, folliculogenesis, ovulation rate, rate of embryo development and the frequency of cleavage and blastocyst formation in vitro, timing of genome activation, and metabolism are like in bovine and human embryos [20–24]. Fifty-fifty though the mechanisms involved in CL maintenance are different, germination and system of CL and length of pregnancy in these two species are comparable [25, 26], suggesting that bovine species could be employed every bit a useful model for agreement human embryo and CL development.

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Cattle grazing effects on the surroundings: Greenhouse gas emissions and carbon footprint

Alan J. Franzluebbers , in Direction Strategies for Sustainable Cattle Production in Southern Pastures, 2020

Enteric methane emission

Globally, CHiv emission contributes about 20% of the estimated human-induced greenhouse gas emissions, second behind CO2 emission at threescore% [6]. In 2011, the atmospheric concentration of CH4 was 1803 ppb (parts per billion) [7], which was more double the concentration of ~700 ppb in 1700 Advertizing [8]. Global sources of CHiv emission are livestock production, rice farming, waste material decomposition (animal waste, ingather residues, and landfills), and fossil fuel mining. Livestock sources of CH4 emission (enteric and manure) account for 20%–34% of all global emissions of CH4 [nine,ten] (Fig. 2.six).

Figure two.vi. Components of the life-bicycle cess for beef production in southern Alberta.

 From K.A. Beauchemin, H.H. Janzen, S.Chiliad. Little, T. McAllister, S.M. McGinn, Life cycle assessment of greenhouse gas emissions from beefiness production in western Canada: a case study, Agric. Syst. 103 (2010) 371–379.

Enteric CHiv from livestock and emission of N2O associated with N fertilizer application in agriculture are the largest contributors to agricultural greenhouse gas emissions (Fig. 2.5). Enteric CH4 emission is a natural by-product from the activeness of rumen microbiota that breaks down cellulose in forages. Variation in CH4 emission from ruminant livestock (cattle, buffalo, sheep, goats, and camels) is controlled largely by feed intake and quality. Greater feed intake and/or lower feed quality leads to greater CH4 emission. Larger animals generally have greater feed intake requirements. For average conditions in the United States, feed dry out affair intake was estimated equally 8.4   lb/24-hour interval for calves (<500   lb live weight), xix.8–22.0   lb/day for growing steers and heifers (>500   lb alive weight), 24.3   lb/solar day for mature beefiness cows, and 48.5   lb/day for lactating dairy cows [eleven]. CH4 production rates tin can exist generalized equally 0.008–0.013   lb CH4/lb dry matter intake (0.055–0.089   lb COii-Cequiv/lb feed intake) for cattle on feed and 0.02   lb CH4/lb dry affair intake (0.136   lb CO2-Cequiv/lb feed intake) for pastured grazing conditions. In addition, consideration has to be given to growth rate of young livestock, equally well as life stage and/or activeness (e.g., lactation, wool growth of sheep, pregnancy, or workload). Enteric CHfour emission from agriculture in the U.s. (102 billion lb CO2-Cequiv) is dominated by beef production (71%), while dairy contributes 25% and swine (nonruminant CH4 produced in the large intestine) contributes <ii% [4].

A life-cycle assessment of beef production in western Canada has given some insights as to the relative proportion of greenhouse gas emissions derived from the cow–calf suckling/grazing period (typical stage of many operations in the Southeastern Usa) to the growing phase on a high-grain diet in the feedlot [12]. The simulation was for a 120-head beef cow herd (1323 lb) with iv bulls and calves fattened on the aforementioned subcontract in southern Alberta over an 8-year period. Cropland was available for producing grain, and native pasture was used for grazing. Suckling calves nursed and fed on either mixed hay or pasture when bachelor. Calving rate was 85%, with birth in February-March and weaning in September. Weaned calves (530  lb) were fed a loftier-forage diet for 110 days [lx% barley (Hordeum vulgare L.) silage and 40% barley grain] with an average daily gain of 2.2   lb/day. On reaching 770   lb, the nutrition was switched to 90% barley grain and x% barley silage for 170 days to reach an boilerplate daily gain of 3.two   lb/mean solar day. Slaughter occurred when cattle reached 1334   lb at 16 months of age. Greenhouse gas emission was 262   lb COii-Cequiv/brood moo-cow/year. This equated to iii.vi   lb CO2-Cequiv/lb live weight and 5.nine   lb CO2-Cequiv/lb carcass weight. The cow–calf organization deemed for 80% of total greenhouse gas emissions, and the feedlot organization was 20%, which comprised 8% from backgrounding and 12% from finishing stages. Enteric CH4 was 63% and N2O from soil and manure was 27% of total greenhouse gas emissions. Of the enteric CH4 emissions, 79% came from breed cows, 9% from finishers, 7% from backgrounders, 3% from bulls, and two% from calves. The authors of this report suggested CH4 emission reduction in the cow–calf component of product be targeted through dietary supplementation with oilseeds [13] and grains [14], greater use of grain-based forages [fifteen] and forage legumes [16], and apply of tannin-containing legumes [17]. Other mitigation options might be improving the reproductive functioning of cows, reducing decease loss of calves, and improving feed conversion efficiencies. The Canadian evaluation considered summertime pasture at steady-country with respect to soil organic C, but significant soil organic C sequestration could significantly reduce net greenhouse gas emissions from moo-cow–calf operations in the Southeastern United states [18].

In another study in southern Alberta, Canada, a spring-calving herd of 350 beef cows, 15 breeding bulls, 60 replacement heifers, and 112 steers were the basis for a comparison of whole-farm greenhouse emissions between dogie-fed and yearling-fed production with and without growth implants [19]. Greenhouse gas emission intensity was half dozen.2   lb CO2-Cequiv/lb carcass weight for calf-feeders (11–14 months of age) without growth implants and v.eight   lb COtwo-Cequiv/lb carcass weight with growth implants. Greenhouse gas emission intensity was 10.7 and 10.1   lb CO2-Cequiv/lb carcass weight without and with growth implants, respectively, for yearling feeders (19–23 months of historic period). Other estimates of greenhouse gas emission intensity vary from iv.four to vii.4   lb CO2-Cequiv/lb carcass weight in Europe [20,21] and 12.0   lb COii-Cequiv/lb carcass weight in Brazil [22].

Greenhouse gas emissions estimate from a life-cycle assessment of beef production in the Us was generally the same as those evaluations in Canada at 5.9   lb COtwo-Cequiv/lb carcass weight [23]. In the U.s.a. simulation, cows weighed 1102   lb, and weaned calves backgrounded on forage for v months before entering the feedlot.

Greenhouse gas emissions from three different beef production strategies in the Midwestern U.s.a. were evaluated with a life-wheel assessment approach using 100 cows and three bulls with ninety% calving charge per unit and fifteen replacement heifers [24]. After calf weaning, systems evaluated were: (1) direct placement into feedlot for finishing, (2) shipment to out-of-state wheat (Triticum aestivum L.) pasture backgrounding prior to the feedlot, and (three) backgrounding and finishing on pasture and hay on a farm. Total greenhouse gas emissions were 1575   lb COtwo-Cequiv/brood cow/year for the direct feedlot arrangement, 2044   lb COii-Cequiv/brood cow/yr for the wheat backgrounding organization, and 1954 lb   COii-Cequiv/brood cow/year for the pasture-finished arrangement. Scaled to a finished calf, greenhouse gas emission was four.0   lb COii-Cequiv/lb live weight for the straight feedlot system, 4.4   lb COtwo-Cequiv/lb live weight for the wheat backgrounding organisation, and 5.2   lb COtwo-Cequiv/lb live weight for the pasture-finished system. When significant soil organic C sequestration (357   lb   C/acre/yr) was factored into the pasture-finished system, greenhouse gas emission was reduced to 3.0   lb COtwo-Cequiv/lb live weight.

A life-bicycle analysis of beef cattle production in Brazil illustrates the complexity of factors involved with system modifications [25]. Authors clearly state several limitations of assumptions, but the process of listing each line item in the assay is informative. Rationalizing the cess along a gradient of intensification allows stakeholders to detect a suitable entry point. Table ii.1 outlines key inputs and outputs of significance in this analysis of beef production in Brazil. A like gradient of direction systems could, and should, be prepared for the United States, particularly for the Southeastern United States. Of import points in this analysis are for reducing land area required to make amend use of natural resources, improving the efficiency of feedstuff utilization to reduce enteric CHiv emission, and limiting energy-intensive Due north fertilizers to reduce CO2 and N2O emissions and other water quality and landscape diversity problems.

Table 2.one. Characteristics of v beef product scenarios along with a gradient of degradation comeback in Brazil [25].

Variable Degraded pasture Moderate pasture Improved pasture—continuous stocking, no TMR Improved pasture—rotational stocking, no TMR Improved pasture—rotational stocking, TMR finish
Forage Urochloa sp. Urochloa brizantha Mixed grass-legume (U. brizantha, Stylosanthes, Arachis) Guinea grass (Panicum maximum cv. Tanzania) Guinea grass (Panicum maximum cv. Tanzania)
Pasture management Natural, no lime-fertilizer Reseeded every 10   year, lime every 10   year, no fertilizer Reseeded every 5   year, lime every v   yr, fertilized with P and K Reseeded every 5   year, lime every 5   year, fertilized with N, P, and Grand Reseeded every 5   year, lime every five   twelvemonth, fertilized with N, P, and One thousand
Cattle breed Undefined—mostly Bos indicus, some B. taurus Mixed—Nellore with Gir, Guzerat, Holstein, Curraleiro, others Nellore cross Nellore cross Nellore cantankerous
Stocking charge per unit 0.2 caput/acre 0.4 caput/acre 0.seven head/acre 1.0 head/acre 1.1 head/acre
Breed characteristics Late first calf, high mortality, slaughtered 3–4 years of historic period First calf at three years, more calves per cow, less bloodshed, finished before First dogie at 2 years, more calves per moo-cow, less mortality, finished earlier Start dogie at ii years, more calves per moo-cow, less mortality, finished earlier Showtime dogie at 2 years, more calves per cow, less bloodshed, finished earlier
Diet at calving Pasture only Pasture with occasional supplement Pasture with mineral supplement Pasture with mineral supplement Pasture with mineral supplement
Nutrition at rearing Pasture only Pasture with occasional supplement Pasture with mineral supplement Rotational grazing, pasture with mineral supplement Rotational grazing, pasture with mineral supplement
Diet at finishing Pasture only Pasture with occasional supplement Pasture with mineral and energy supplements Rotational grazing, pasture with mineral, protein, and energy supplements Confinement with full mixed ration feed
Animal management Minimal, random breeding, compulsory vaccinations Basic, random convenance, compulsory vaccinations Breeding flavour, controlled weaning, parasite controls Breeding flavour, controlled weaning, parasite controls Breeding season, controlled weaning, parasite controls
Performance documentation Minimal Management indicators Individual ID, calving number and date, gain recorded Individual ID, calving number and date, gain recorded Private ID, calving number and date, proceeds related to specific grazing area
Diet digestibility 49% 56% 60% 63% 63%–70%
Pregnancy rate 60% 65% 75% 75% 75%
Carcass weight 441–507   lb 463–529   lb 485–551   lb 485–551   lb 518–584   lb
Weaning weight 309–353   lb 342–375   lb 375–408   lb 375–408   lb 375–408   lb
Finishing proceeds 0.vii–0.9   lb/day one.ane–1.3   lb/day 1.3–1.vii   lb/day i.vi–ii.0   lb/day 2.six–iii.iii   lb/solar day
Carcass yield 28   lb/acre 67   lb/acre 125   lb/acre 180   lb/acre 198   lb/acre
CHiv emission (lb CO2-Cequiv/lb carcass) 15.3 10.two 6.8 5.seven five.0
N2O emission (lb CO2-Cequiv/lb carcass) 0.7 0.ix ane.ane 2.half dozen ii.4
C footprint (lb CO2-Cequiv/lb carcass) fifteen.9 11.two 8.1 8.8 8.1

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