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Minimising the stress of weaning of beef calves: a review
Daniel Enríquez, Maria J H?tzel, Rodolfo Ungerfeld
Acta Veterinaria Scandinavica , 2011, DOI: 10.1186/1751-0147-53-28
Abstract: In extensive systems, beef calves are usually weaned at around six months of age. The main objective is to improve the cow's body condition, thus preparing her for the forthcoming lactation. Although increasing the reproductive and productive performance of the herd, abrupt weaning is a source of stress for the cow [1-4] and calf [5-8]. This effect is especially acute and prolonged for the calf, which at weaning is subjected to multiple stressors such as the loss of the mother and access to the udder and milk, and changes in the social and physical environment [9,10].Some management strategies have been proposed that aim to reduce the stress associated with weaning, so that production goals are in line with ethical requirements of society regarding livestock production [11,12]. In general, these techniques involve separating the termination of suckling from the social separation of the calf-dam pair, for example by keeping the calves separated from the dams through fenceline contact for a period before the final separation [5] or with the aid of nose-flaps that allow social contact but not suckling [1].This paper presents the current knowledge available in the literature on the establishment and maintenance of maternal-filial bond in beef cattle. This bases a discussion on the possible relationship between the mechanisms involved in these processes and the behavioural and physiological response that follows when this bond is severed. Finally, we discuss the advantages and limitations of the methods proposed to improve welfare of calves at weaning. Welfare in this text is understood as the possibility to express natural behaviours and the absence of both suffering and negative influences on the organism which may impair homeostasis.The dam improves her reproductive success by investing in the survival of the newborn, which she achieves by providing it with care and nutrition [13-15]. A number of morphological, physiological and psychological mechanisms that result in
Effects of the weaning age of calves on somatic development and on reproductive performance of beef cows
Vaz, Ricardo Zambarda;Lobato, José Fernando Piva;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000500016
Abstract: this study evaluated body development and reproductive performance of beef cows whose calves were submitted to early weaning (76 days of age), or conventional weaning (148 days of age). it was used 141 braford cows that calved in 2004, 2005, and 2006 to evaluate weight at calving at 76 days, weight at calving at 148 days, weight at the beginning and end of the breeding season, variation of the average daily weight, body condition, pregnancy rate, and calving interval. dams of calves weaned at 148 days of age showed daily weight gain higher body weight and better body condition at 148 days of age. the weights at the end of breeding season and average weight gain during the breeding season were higher in early weaning cows than in conventional cows. pregnancy rate of early weaning cows (86.34%) was higher than those submitted to weaning at conventional age (55.45%). pasture interval was similar among early weaning cows and conventional weaning cows. the best benefit on reducing weaning age in pregnancy rate was in primiparous cows. there was significant interaction between weaning age and the year for calving interval and milk production. the early weaning of calves carried out at 76 days of age allows cows to better weight recovery in the post-weaning and breeding periods, improving their body condition and consequently increasing pregnancy rate regarding to cows whose calves suckled until 148 days of age.
Effect of abrupt weaning at housing on leukocyte distribution, functional activity of neutrophils, and acute phase protein response of beef calves
EM Lynch, B Earley, M McGee, S Doyle
BMC Veterinary Research , 2010, DOI: 10.1186/1746-6148-6-39
Abstract: Treatment × sampling time interactions (P < 0.05) were detected for total leukocyte and neutrophil counts, all lymphocyte subsets, mean fluorescence intensity of CD62L+ neutrophils, and percentage neutrophils performing phagocytosis. On d 2, total leukocyte and neutrophil count increased (P < 0.001), and percentage CD4+ and CD8+ lymphocytes, percentage phagocytic neutrophils, mean fluorescence intensity of CD62L+ neutrophils decreased (P < 0.05) in W compared with baseline (d 0), whereas they were unchanged (P > 0.05) in C. On d 2, percentage WC1+ lymphocytes decreased (P < 0.05), whereas percentage MHC class II+ lymphocytes increased (P < 0.05) in W and C, however the magnitude of change was greater in W than C. There were no treatment × sampling time interactions (P > 0.05) for monocyte, eosinophil, and basophil counts, percentage G1+ neutrophils, or percentage oxidative burst positive neutrophils.Abrupt weaning resulted in increased neutrophil counts and impaired trafficking and phagocytic function. Together with the changes in lymphocyte subsets, the results suggest that there was a greater transitory reduction in immune function at housing in abruptly weaned than non-weaned beef calves.Weaning is an inherent husbandry practice in cow-calf beef production systems that imposes physical, psychological, and nutritional stressors on calves. Integrated calf-to-beef production systems, such as seasonal grass-based systems, often combine weaning and housing [1], whereas non-integrated systems often combine weaning with additional stressors such as transportation and marketing, prior to entry into feedlots [2]. Following abrupt weaning, beef calves exhibit distress behaviours [3,4], with alterations in hormonal mediators of stress [5,6] and immune function [7-9] evident up to 7 d post-weaning. Furthermore, weaning is considered to be a predisposing factor to bovine respiratory disease (BRD) [10,11].Neutrophils provide the first line of cellular defence against pathogens
Effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein and behavioural responses of abruptly weaned and housed beef calves
Eilish M Lynch, Mark McGee, Sean Doyle, Bernadette Earley
BMC Veterinary Research , 2012, DOI: 10.1186/1746-6148-8-1
Abstract: There was a treatment × sampling time interaction (P < 0.05) for percentage CD4+ and WC1+ (γδ T cells) lymphocytes and concentration of plasma globulin. On d 2, percentage CD4+ lymphocytes decreased (P < 0.001) in both treatments. Subsequently on d 7, percentage of CD4+ lymphocytes increased (P < 0.01) in CS compared with d 0, whereas percentage of CD4+ lymphocytes in NCS did not differ (P > 0.05) from d 0. On d 2, WC1+ lymphocytes decreased (P < 0.05) in both treatments but the decrease was greater (P < 0.05) in NCS than CS. Subsequently, percentages did not differ (P > 0.05) from pre-weaning baseline. On d 2, the increase in concentration of globulin was greater (P < 0.05) in CS compared with NCS, and subsequently there was no difference between treatments. Pre-weaning ADG was 1.07 (s.e.m.) (0.26) kg and 0.99 (s.e.m.) (0.26) kg for CS and NCS, respectively. Post-weaning, CS calves spent more time lying compared with NCS calves.Calves supplemented with concentrate prior to weaning had a lesser reduction in WC1+ lymphocytes, increased percentage CD4+ lymphocytes and concentration of total protein, and spent more time lying post-weaning, compared with non-supplemented calves.Within seasonal, grassland-based suckler beef production systems in Ireland, calves are generally spring-born and reared with their dam at pasture for approximately 8 months until the end of the grazing season in autumn when they are weaned. At, or, shortly after weaning, calves are housed indoors over the winter period and offered grass silage, which is generally supplemented with concentrates [1]. Concentrate supplementation of suckling, grazing beef calves prior to weaning is commonly referred to as 'creep feeding', and serves to compensate for decreasing milk yield and forage, and to improve calf weaning weights [2-6]. Additionally, this practice is often advocated as a means of reducing weaning stress in calves through the familiarisation to a palatable feed, such as concentrates [7] and has
Evaluation of forage-based weaning systems in spring-born cross-bred beef calves  [PDF]
John Fredrick Odhiambo, Robert Arthur Dailey, Ronnie Helmondollar, James Yeager Pritchard, Phillip Irvin Osborne
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.32015

Preconditioned calves have greater marketvalue per unit weight than normal-weaned calves. Development of a low cost forage-based preconditioning system allows producers to add value to their calf-crop. This study evaluated calf performance in three forage-based weaning systems; early-weaned calves were backgrounded in legume/grass forage plots and supplemented with commercial preconditioning feed (Treatment 1) or an on-farm corn-mix (Treatment 2). Control (Treatment 3) calves suckled for an additional 45 days. Supplements provided2.17 kgTDN/calf/ day. Weights were collected on days -30, 0 and 45 with respect to early weaning, from135 inyear 1 and 150 calves in each of the two subsequent years. Effects of treatment, age of dam, sex of calf and their interactions on calf weight gain were analyzed by analysis of covariance using GLM procedures of SAS. Marginal effects of treatment and feed cost were used to evaluate economic feasibility. Sensitivity analyses were evaluated for anticipated market fluctuations in feed costs and calf premiums. Data are reported as least squares means. Calf weight gains differed (P < 0.001) among treatments and averaged 1.16, 1.03 and1.04 kg/calf/day for commercial supplement, corn-mix and controls, respectively. Calves from 2-year-old cows gained less (P < 0.001) weight compared to those from cows 3 - 4 and ≥5 years of age (44.8, 48.9 and51.5 kg, respectively). Steers calves gained more (P < 0.001) weight compared to heifer calves (51.2 vs.45.7 kg, respectively). Net returns for corn mix were greater than those for commercial feed ($1.48 vs. $1.35/kg weight gain, respectively). Sensitivity analyses indicated that selection of preconditioning treatment to a large degree was less sensitive to significant changes in market conditions due to the large gap in marginal costs between the two treatments. In conclusion, forage-based weaning systems can be utilized to precondition calves providing an economical means for calf weight gain and profit

Evaluation of Non-Genetic Factors Affecting Birth Weight in Sistani Cattle
Hossein Bazzi
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2011.3095.3099
Abstract: The study under taken investigates the effects of some non-genetic factors (Sex of calf, year and season of birth, parity and calving difficulty) affecting on birth weight in Sistani cattle. Data were collected on 932 (466 males and 466 females) Sistani calves from the progenies born in the Sistani Cattle Research station of Sistani and Baluchistan province in Iran during the period from 1989-2007. Analysis of variance indicated that the effects of sex of calf, year and season of birth, parity and calving difficulty with gestation length as a covariate on birth weight were significant (p<0.01). The least square mean for birth weight of Sistani calves was found to be 24.143±0.509 kg. The effect of calf sex on birth weight was highly significant (p<0.01). Male calves were 1.935 kg heavier at birth than females. Birth weights of male calves were 7-8% heavier than female calves. The winter born calves had the highest (25.168 kg) birth weight. Calves born in early parities were lighter in weight than those born to late-parity dams. Difference between the means for maximum and minimum years is 6.023 kg. Sistani cattle difficult calving occurred in 1.2%. First parity cows exhibited more frequent calving difficulty whereas among other parities there were no statistically significant differences.
Main critical factors affecting the welfare of beef cattle and veal calves raised under intensive rearing systems in Italy: a review
Giulio Cozzi,Marta Brscic,Flaviana Gottardo
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2009.s1.67
Abstract: This review describes the principal causes of poor welfare in beef cattle and veal calves raised in intensive husbandry systems in Italy. Nowadays there are no specific regulations in force for beef cattle welfare. However, a document produced in 2001 by the Scientific Committee on Animal Health and Animal Welfare of the European Commission on Health and Consumer Protection identified the main causes of inadequate welfare levels in the different cattle rearing systems in Europe. In Italy and in the Po Valley in particular, the beef cattle farms are mainly finishing units characterised by animals kept at high density in multiple pens and fed high starch diets. Under these rearing conditions the limited space allowance is one of the most important issues impairing animal welfare. Other risk factors for poor welfare related to the housing structures are type of floor, space at the manger, number of water dispensers and lack of specific moving and handling facilities. Microclimatic conditions can be critical especially during the summer season when cattle can experience heat stress. The feeding plan adopted in the Italian beef farms may be another factor negatively affecting the welfare of these animals due to the low content of long fibre roughage which increases the risk of metabolic acidosis. In the veal calf rearing systems there has been a mandatory introduction of the new system of production according to the European Council Directives 91/629/EEC and 97/2/EC. Farms had to adopt group housing and to provide calves with an increasing amount of fibrous feed in addition to the all-liquid diet. Despite this specific legislation, several risk factors for calves’ welfare can still be identified. Some of them are related to the housing system (type of floor, air quality, feed and water supply equipment and lack of loading facilities) and some others to the feeding plan (type and amount of roughage, quality of milk replacers). Recent studies have shown that the welfare of veal calves and beef cattle can be severely affected by the quality of the stockmanship and particularly by negative human-animal interaction.
Characterisation of physiological and immunological responses in beef cows to abrupt weaning and subsequent housing
Eilish M Lynch, Bernadette Earley, Mark McGee, Sean Doyle
BMC Veterinary Research , 2010, DOI: 10.1186/1746-6148-6-37
Abstract: Post-weaning, concentration of cortisol and dehydroepiandrosterone were unchanged (P > 0.05). Rectal body temperature, neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.01) on d 2 compared with pre-weaning baseline. Lymphocyte and neutrophil number decreased (P < 0.05) on d 2 to 7 and d 7 to 21, respectively, compared with pre-weaning baseline. Interferon-γ production decreased (P < 0.05) on d 2 compared with pre-weaning baseline. An increase (P < 0.05) in acute phase proteins, fibrinogen and haptoglobin was evident on d 2 to 35 compared with pre-weaning baseline. Concentration of glucose increased on d 2 to 28, whereas non-esterified fatty acid decreased on d 2 to 35 compared with pre-weaning baseline. Post-housing, concentrations of cortisol, rectal body temperature, total leukocyte number, and glucose were unchanged (P > 0.05). On d 2 post-housing, neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.05), whereas lymphocyte number and concentrations of dehydroepiandrosterone, fibrinogen and non-esterified fatty acid decreased (P < 0.05) compared with pre-housing baseline. Concentration of haptoglobin increased (P < 0.05) on d 14 to 21 post-housing.A transitory increase in neutrophil number and decrease in lymphocyte number, increased neutrophil:lymphocyte ratio coupled with decreased interferon-γ production, and increased concentration of acute phase proteins indicate a stress response in cows post-weaning, whereas post-housing, changes were less marked.Within seasonal grassland-based, spring-calving suckler beef production systems calves are generally allowed continuous and unlimited nursing of the dam for approximately 6 to 8 months until weaning at the end of the grazing season. Husbandry management practices, including weaning and housing, form integral components of these beef production systems, and often expose beef cattle to novel environmental, physical and psychological stressors. Research measuring stress-related variab
Effect of Feeding Selenium-Fertilized Alfalfa Hay on Performance of Weaned Beef Calves  [PDF]
Jean A. Hall, Gerd Bobe, Janice K. Hunter, William R. Vorachek, Whitney C. Stewart, Jorge A. Vanegas, Charles T. Estill, Wayne D. Mosher, Gene J. Pirelli
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0058188
Abstract: Selenium (Se) is an essential micronutrient in cattle, and Se-deficiency can affect morbidity and mortality. Calves may have greater Se requirements during periods of stress, such as during the transitional period between weaning and movement to a feedlot. Previously, we showed that feeding Se-fertilized forage increases whole-blood (WB) Se concentrations in mature beef cows. Our current objective was to test whether feeding Se-fertilized forage increases WB-Se concentrations and performance in weaned beef calves. Recently weaned beef calves (n = 60) were blocked by body weight, randomly assigned to 4 groups, and fed an alfalfa hay based diet for 7 wk, which was harvested from fields fertilized with sodium-selenate at a rate of 0, 22.5, 45.0, or 89.9 g Se/ha. Blood samples were collected weekly and analyzed for WB-Se concentrations. Body weight and health status of calves were monitored during the 7-wk feeding trial. Increasing application rates of Se fertilizer resulted in increased alfalfa hay Se content for that cutting of alfalfa (0.07, 0.95, 1.55, 3.26 mg Se/kg dry matter for Se application rates of 0, 22.5, 45.0, or 89.9 g Se/ha, respectively). Feeding Se-fertilized alfalfa hay during the 7-wk preconditioning period increased WB-Se concentrations (PLinear<0.001) and body weights (PLinear = 0.002) depending upon the Se-application rate. Based upon our results we suggest that soil-Se fertilization is a potential management tool to improve Se-status and performance in weaned calves in areas with low soil-Se concentrations.
Vaccination protocol and bacterial strain affect the serological response of beef calves against blackleg
Araujo, Rafael F.;Curci, Vera C.L.M.;Nobrega, Fabiana L.C.;Ferreira, Rosa M.M.;Dutra, Iveraldo S.;
Pesquisa Veterinária Brasileira , 2010, DOI: 10.1590/S0100-736X2010000700008
Abstract: the serological response of beef calves was evaluated with different vaccination regimens against blackleg, using an official strain (mt) and a field-collected strain of clostridium chauvoei as antigens. sixty calves were randomly allocated to four different groups and were submitted to distinct vaccination protocols with a commercial polyvalent vaccine. group g1 was first vaccinated at four months of age and a booster shot was given after weaning, at eight months. group g2 was given the first dose at eight months and a booster shot 30 days later. group g3 was vaccinated only once at eight months and the control group was not vaccinated. these alternative vaccination regimens were proposed in an effort to adequately protect cattle under open-field farming conditions. serological evaluations were made by elisa at 4, 8, 9 and 10 months of age. both groups receiving booster shots had a significantly increased serological response 30 days later. however, the serum igg levels against c. chauvoei were significantly higher in the calves that were first vaccinated at four months. at 10 months, the two booster shot groups (g1 and g2) had similar serological responses, while the calves that were treated with a single dose of vaccine at weaning (g3) had a response that was similar to that of the control group. the serological response of the calves was significantly inferior at several of the evaluation times when the field strain of the bacteria was used as a challenge antigen instead of the official mt strain. the serological response of calves that are vaccinated twice was found to be satisfactory, independent of the first injection being made at four or eight months of age. it was also concluded that it would be useful to include local bacterial strains in commercial vaccine production.
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