Abrupt Weaning Research Articles

A low-carbon high inulin diet improves intestinal mucosal barrier function and immunity against infectious diseases in goats.

Abrupt weaning is a major stressful event, contributing to intestinal abnormalities and immune system dysfunction in weaned kids. Inulin is a prebiotic fiber with many positive functions, including promoting intestinal fermentation and enhancing host immunity in monogastric animals. However, the effects of a high-inulin, energy-rich diet on ruminal fermentation characteristics, methane emission, growth performance, and immune systems of weaned kids have not been investigated. A fully automated in vitro fermentation system was used to investigate ruminal fermentation characteristics and methane emission of a mixed substrate of inulin and fat powder (1.31: 1) in comparison with maize grain-based starter concentrate. During a 1-week adaptation and 4-week trial phase, 18 weaned kids (8.97 ± 0.19 kg) were randomly assigned to two groups, one with a conventional diet (83% maize grain; CON) and the other with a low-carbon, high-inulin diet (41.5% maize grain, 14.4% fat powder, 18.9% inulin; INU). In the in vitro rumen fermentation experiment, the total gas production was not different (p > 0.05); however, a lower (p < 0.05) methane production was observed for INU as compared to CON. The average daily gain and the ratio of feed intake and growth performance of kids fed with INU were higher (p < 0.05) than those fed with CON. Serum concentrations of alanine transaminase (ALT) and lactate dehydrogenase (LDH) were lower (p < 0.05), whereas the concentration of high-density lipoprotein (HDL) and cholesterol (CHOL) were higher (p < 0.05) in kids fed with the INU diet as compared CON. Dietary inulin significantly increased (p < 0.05) the secretion of immunoglobulins (IgA, IgG, and IgM) and inflammatory cytokines (IFN-γ and IL-10) in ileum tissue. Although no differences (p > 0.05) were observed in mRNA expression of tight junction markers, the INU diet tended to increase (p = 0.09) gene expression of ribosomal protein S6 kinase beta-1 (P70S6K) in the mammalian target of rapamycin (mTOR) pathway of longissimus dorsi muscle. Our findings highlighted that a low-carbon high-inulin energy-rich diet could be used as a promising strategy to improve gut immunity and growth performance of weaned kids under abrupt weaning stress and reduce methane production.

Weaning Method Evaluation for Beef Cattle

Weaning is a stressful event for calves. Various management practices have been suggested to reduce weaning stress. The purpose of this study was to evaluate three different weaning management practices on calf gains at weaning. Eighty-eight bull and heifer calves were assigned to one of three weaning treatments at two research locations. The weaning management options were abrupt weaning, fence-line weaning, and use of a nose-flap weaning device. Calves were weighed at the start of the measurement period and then two weeks later after weaning was completed. Calves that were weaned using the nose-flap method had significantly lower gains than calves that were abruptly weaned or fence-line weaned. Bulls also gained more during this weaning period than heifers did. Generally, fence-line weaned calves have a greater gain than abruptly weaned calves, but in this study where the calves were abruptly weaned and only moved a few miles from the dams, we did not see a difference in gains during the weaning event between abrupt weaning and fence-line practices. The nose-flap device seemed to lead to a lower gain for calves during this period and more research on the device is needed before determining the best weaning management practice.

Post-weaning performance of Nellore calves subject to different weaning methods

Context Different methods of weaning have been validated to reduce the stress of calves. A novel approach has been described by ranchers whereby the zebu calves are kept in the same pasture with trainer’s cows, however, no scientific evidence is available to date. Aims This study investigated the effect of different weaning methods on the physiological responses, temperament, and post-weaning performance of calves. Methods One hundred and eighty three Nellore calves were used, including 93 males (initial bodyweight: 219.8 ± 3.25 kg (avg ± s.e.), initial age: 244 ± 14.3 days (avg ± s.e.) and 90 females (219.7 ± 3.25 kg, 246 ± 14 days (avg ± s.e.)). The calves were randomly assigned to three weaning methods: Abrupt – total separation of dam and calf; Fenceline – physical separation between dam and calf by wired fence; and Leadership – total separation between dam and calf and use of social facilitator cows. Heart rate, respiratory rate and blood samples for cortisol analysis were taken on Days 0, 1, 4, and 7 post-weaning. Temperament was assessed on Days 0, 7, and 82. Performance and body condition score (BCS) was measured at 0, 42, and 82 days post-weaning. Key results No interaction (P &gt; 0.05) between the weaning methods and sex of the calves was detected. Heart and respiratory rates were not influenced (P &gt; 0.05) by weaning methods on Days 1 and 7 post-weaning. Furthermore, females showed higher heart rate at Day 7 post-weaning (P &lt; 0.05). Weaning methods and sex of calves did not affect the cortisol levels (P &gt; 0.05). Calves on Fenceline and Leadership weaning methods had higher final bodyweight and average daily gain (ADG) from weaning until 82 days post-weaning (P &lt; 0.05) compared to the Abrupt weaning method, which had negative ADG (−26 g/day) on the first 42 days and the lowest bodyweight until 82 days post-weaning (P &lt; 0.05). Conclusions The presence of social facilitators at weaning, using dams in the Fenceline method or non-related cows in the Leadership method, ensures greater post-weaning performance. The Leadership method can be the most advantageous due to its easy handling. Implications The weaning strategies contribute to good animal performance and shorten the post-weaning and finishing phases.

Aleitamento materno em crianças com microcefalia por síndrome congênita do vírus Zika

INTRODUCTION: Children with microcephaly are at increased risk for global developmental delay, physical and intellectual disability, and sensorineural changes. Records on growth and development, as well as records on the prevalence of breastfeeding, are still scarce in this population. OBJECTIVE: To identify duration and characterization of breastfeeding in children with microcephaly due to congenital ZIKV syndrome (SCZV) seen at a referral service. METHODOLOGY: Descriptive, cross-sectional, quantitative study. Data collection was performed on medical records and during interviews, using standardized questionnaires, during the months of September and November 2019. Descriptive statistical analysis was performed using the SPSS 25.0 program. RESULTS: Fourteen children met the inclusion criteria and were included in this study. The average age was 43 months (20-50), and the average head circumference corresponded to 29.85 cm (25-34). Most children (92.9%) were breastfed. Eight children (57.2%) received exclusive breastfeeding and five (35.7%) received predominant breastfeeding. Only 21.4% suckled in the first hour of life. The mean time of BF was 14.67 months (04-37). Twelve mothers had already weaned during the data collection period. Three (21.4%) underwent gradual weaning and nine (64.3%) underwent abrupt weaning. All children used artificial teats (pacifiers, n = 14; baby bottles, n = 13), and in 50% of cases, this use occurred while still in the maternity ward. CONCLUSION: This study found a prevalence of 92.9% of breastfed children within the studied group, and an average duration of breastfeeding less than 2 years of age.

1217: ABRUPT DISCONTINUATION VERSUS WEANING OF HYDROCORTISONE IN THE TREATMENT OF REFRACTORY SEPTIC SHOCK

Introduction: Current guidelines lack guidance on discontinuation of hydrocortisone (HCT) used in the treatment of refractory septic shock, thus discontinuation strategies vary widely in practice. The purpose of this study was to identify the incidence of recurrent shock and the associated safety outcomes when comparing HCT discontinuation strategies used for septic shock. Methods: A retrospective, cohort study was conducted with medical critical care patients grouped based on HCT discontinuation strategy: abrupt discontinuation (discontinuation while dose ≥200 mg/day) and weaning (use of any dose < 200 mg/day). Adult patients with septic shock who received IV HCT at a dose of ≥200 mg/day for ≥48 hours prior to discontinuation or wean were included. The primary outcome was the recurrent shock within 24 hours from HCT discontinuation, defined as restarting vasopressors for at least 2 hours, or, if patients still had vasopressors active at HCT discontinuation, an increase in vasopressors to ≥0.2 mcg/kg/min in norepinephrine equivalents or the addition of another vasopressor. Secondary outcomes included intensive care unit (ICU) length of stay (LOS), duration of mechanical ventilation, and duration of HCT therapy. Safety outcomes included rates of gastrointestinal bleed, hyperglycemia, and hypertension. Results: A total of 149 patients were included in the analysis: 89 in the abrupt group and 60 in the wean group. All patients received 200-300 mg/day of HCT initially. Both groups had similar durations of HCT therapy prior to their discontinuation/wean. Recurrent septic shock occurred in 6/89 patients (6.7%) in the abrupt discontinuation group and 6/60 patients (10%) in the weaning group (p=0.473). No differences were observed for ICU LOS or duration of mechanical ventilation, but patients in the abrupt group spent fewer total days on any dose of HCT (difference, 3 days, p< 0.001). For safety outcomes, patients in the wean group experienced higher rates of hyperglycemia during their wean compared to patients who had HCT abruptly discontinued (33.3% vs 19.1%, p=0.049); there were no differences in other safety outcomes. Conclusions: Among adults treated with HCT for septic shock, there was no difference in rates of recurrent shock when comparing a weaning strategy to an abrupt discontinuation strategy.

Postweaning growth and feeding behaviour in pigs: effect of heavier hybrid and weaning intact litters in farrowing pens for loose-housed sows

Abrupt weaning of four-week-old pigs is associated with multiple stressors. Housing pigs in intact litters is a way to reduce the stress associated with moving and mixing of unfamiliar pigs. Furthermore, higher weaning weight may improve pigs’ robustness against postweaning stressors. In the present study, it was investigated whether: (1) A heavier pig hybrid, and (2) weaning intact litters in the farrowing pen for loose-housed sows could increase postweaning feeding behaviour and growth. Two sow hybrids (DanBred LY (DB) and Topigs Norsvin TN70 (TN)) and two weaning strategies (the litter stayed intact in the farrowing pen after removing the sow (STAY), or two litters were moved and mixed in conventional weaner pens (MOVE)) were compared in a 2 × 2 factorial design. In total, 57 litters from four batches were included in the study. The TN hybrid sows gave birth to heavier piglets but smaller litter sizes and had more functional teats than DB sows. At weaning, TN pigs were heavier than DB. The number of feed trough (FT) visits on the day before weaning was low in both hybrids. On the day after weaning, the number of FT visits was higher in MOVE compared to STAY, and in TN-STAY compared to DB-STAY. The average daily gain the first two days postweaning was negative in both hybrids and weaning strategies but more pronounced in DB than TN, and STAY tended to lose more weight than MOVE. Over the entire 28-day postweaning period, there was an interaction between hybrid and weaning strategy in that TN-STAY (392 g/d) had higher growth than both TN-MOVE (251 g/d) and DB-MOVE (283 g/d), whereas growth of DB-STAY (316 g/d) was intermediate. In addition, higher weaning weight was associated with a lower number of FT visits and greater weight loss the first two days postweaning but higher growth over the 28-day postweaning period. The results show that abrupt weaning at four weeks of age causes weight loss the first days postweaning despite being housedas intact litters, most likely due to low feed consumption. However, the combination of a heavier pig hybrid and housing intact litters in the farrowing pen postweaning resulted in a higher growth performance over the 28-day postweaning period. In conclusion, pigs that are heavier at weaning reach better growth performance in the longer term, despite having the largest acute postweaning growth depression and fewest FT visits on the day before and after weaning.

Lycopene Affects Intestinal Barrier Function and the Gut Microbiota in Weaned Piglets via Antioxidant Signaling Regulation

In pig production, early and abrupt weaning frequently causes weaning stress, which manifests as oxidative damage, barrier disruption, and digestion and absorption capacity declines. Lycopene exhibits beneficial antioxidant capacity in both humans and other animal models. The present study aimed to investigate the effects of lycopene supplementation on early weaning stress in piglets and the underlying mechanisms by examining the oxidative stress state, gut intestinal barrier function, and the gut microbiota. Twenty-four 21-day-old weaned piglets [Duroc × (Landrace × Yorkshire); castrated males; 5.48 ± 0.10 kg initial body weight] were randomly assigned to 2 treatments. The piglets were fed a basal diet (control treatment) or a basal diet supplemented with 50 mg/kg lycopene (lycopene treatment) for 28 days. The serum lipid levels, serum and jejunum enzyme activities, jejunum morphology, mRNA and protein expression, and gut microbiota were determined. Compared with the control treatment, lycopene supplementation increased the serum catalase activity (P = 0.042; 62.0%); serum total cholesterol concentration (P = 0.020; 14.1%); and jejunum superoxide dismutase activity (P = 0.032; 21.4%), whereas it decreased serum (P = 0.039, 23.0%) and jejunum (P = 0.047; 20.9%) hydrogen peroxide concentrations. Additionally, lycopene increased the mRNA and protein expression of NFE2-like bZIP transcription factor 2 (214.0% and 102.4%, respectively) and CD36 (100.8% and 145.2%, respectively) in the jejunum, whereas it decreased the mRNA and protein expression of Kelch-like ECH-associated protein 1 (55.6% and 39.8%, respectively ). Lycopene also improved jejunal morphology, increasing the villus height (P = 0.018; 27.5%) and villus:crypt ratio (P < 0.001; 57.9%). Furthermore, it increased the abundances of potentially beneficial bacterial groups, including Phascolarctobacterium and Parasutterella, and decreased those of potentially pathogenic bacterial groups, including Treponema_2 and Prevotellaceae_unclassified. Lycopene supplementation strengthens the intestinal barrier function and improves the gut microbiota in weaned piglets by regulating intestinal antioxidant signaling.

Maternal supplementation with a casein hydrolysate and yeast beta-glucan from late gestation through lactation improves gastrointestinal health of piglets at weaning

Improving maternal nutrition during pregnancy/lactation is a promising strategy to maximise the intestinal health of piglets undergoing abrupt weaning under commercial production conditions. This experiment investigated the effects of maternal supplementation of a casein hydrolysate and yeast β-glucan (CH-YBG) from day 83 of gestation until weaning (day 28) on sow faecal microbial populations and measures of piglet gastrointestinal health parameters at weaning. Sows (n = 10 sows/group) were assigned to: (1) control diet, and (2) control diet + CH-YBG. Maternal supplementation increased the abundance of the phylum Firmicutes, including members Lactobacillus in the sows faeces, with a concomitant increase in the caecal abundance of Lactobacillus in the weaned piglets compared to the controls. Piglets weaned from the supplemented sows had increased villus height in the duodenum (P < 0.05) and increased villus height to crypt depth ratio in the jejunum, as well as a decreased expression of the proinflammatory cytokine genes (IL6/TNF/TGFB), the tight junction gene CLDN3 and the mucin gene MUC2 in the duodenum/jejunum compared to the controls (P < 0.05). In conclusion, maternal CH-YBG supplementation during pregnancy/lactation improved microbial, structural, and inflammatory measures of gastrointestinal health of piglets at weaning. This is a promising strategy to alleviate the challenges that occur with early abrupt weaning in commercial pig production.

Comparing gradual debonding strategies after prolonged cow-calf contact: Stress responses, performance, and health of dairy cow and calf

We assessed effects of two-step debonding strategies in calf rearing systems with different types of prolonged cow-calf contact (CCC) on stress responses, health and performance of dairy cows and calves. Forty-eight Holstein Friesian cow-calf pairs had either: 1) full contact including suckling, where contact was reduced before weaning via fence-line separation at day 49 (FC-FS) (n = 10); 2) full contact, where contact was reduced at day 56 by fitting calves with a nose-flap (FC-NF) (n = 10); 3) partial contact (calves were housed in a pen adjacent to the cow area allowing physical contact on initiative of the dam but no suckling), where contact was reduced before weaning by moving the calf box from the wall to prevent physical contact at day 49 (PC-BW) (n = 6); 4) partial contact, where contact was reduced the week after weaning by moving the calf box away from the wall at day 63 (PC-AW) (n = 12); 5) no contact (calves were removed from dam directly after birth and housed in a calf barn), calves were weaned at day 56 (NC) (n = 10). Between weeks 7–10, we assessed physiological stress parameters, weight gain, and the health status of calves, plus general activity patterns based on accelerometer sensor data of cow-calf pairs before, during and after the debonding interventions. Additionally, calves were subjected to four consecutive behavioural tests (i.e. open field, novel object, voluntary human approach and involuntary human approach test) prior to permanent separation at day 70 and their behavioural responses were assessed via video recordings to assess fearfulness. Machine-harvested milk yields of cows were evaluated during weeks 6–12. Data were analyzed with (generalized) linear mixed models. Throughout the debonding period, FC-NF calves had an impaired growth rate (P = 0.02). In weeks 6–9, FC-FS and FC-NF cows had lower machine-harvested milk yields than PC-BW, PC-AW, and NC cows (P ≤ 0.01). We found no differences in responsiveness of calves to behavioural tests, except that NC calves exhibited more solitary play events compared to PC and FC calves in the novel object test (P = 0.002). Overall, our results imply that calves with partial CCC showed low stress responses to debonding, whereas abrupt weaning with a nose-flap during full contact seemed most stressful. Machine-harvested milk yield of FC cows seemed to recover once calves were weaned. More research into strategies to improve the process of debonding is warranted.

Rearing goat kids away from their dams 1. A survey to understand rearing methods

Despite an estimated global goat population of over one billion, little is known about methods being used to feed milk to artificially reared kids (reared away from their dams) and how kids are weaned from these systems. Quantifying and characterising current methods utilised on farms will enable future targeted research to investigate best practice methods for milk feeding and weaning of artificially rearedkids.A recall-based survey that investigated on-farmkid-rearingpractices (focusing on the milk feeding and weaning stages) was distributed via social media, and regional goat organisations across multiple countries. A total of 242 responses from 16 countries were collected and geographically grouped. Responses that could not be grouped sufficiently were removed (nine responses from eight countries). A total of 233 responses from eight countries (United States of America (USA) 72; United Kingdom (UK) 71; Australia 33; Canada 23; New Zealand 20; European Union (EU) 14), were analysed. Most farms (217; 93%) bred their own kids. The most common milk feeding method was bottle feeding, used on 135 farms (57.9%), followed by ad libitum feeding used by 72 (30.9%). A relationship between number of kids reared and feeding system was identified, χ2(3, N = 233) = 89.605,P < 0.001, with farms rearing > 100 kids more likely to feed milk ad libitum. A total of 170 farms (72.9%) were weaned based on a target age and 85 (36.4%) on a target weight, 53 (22.7%) used both and 45 (19.3%) neither. Target weaning ages and weights varied across countries; the median age was 84 days (interquartile range (IQR) 56–84), and the median weight was 16 kg (IQR 15–18). A difference was found between milk feeding systems for weaning method (Χ2(2, N = 232) = 63.797,P≤0.001), with kids most likely to be abruptly weaned from ad libitum systems (or gradually weaned from bottle feeding). Abrupt weaning was used by 67 farms (28.8%), and gradual weaning was used by 165 (71.1%). Gradual weaning strategies included reducing milk quantity (150 farms; 93% of farms providing detail) and diluting milk (six farms; 4%). A total of 169 (72.5%) supplied enrichment that met the survey’s definition; items to climb on/hide in were most common, provided by 157 farms (92.8%). Findings suggest differing practices in smaller-scalebottle-fedversuslarger-scalead libitummilksystems, likely reflecting differing system needs.This highlights a requirement for welfare-focused research in kids reared artificiallyin order to identify and communicatebest practices to ensure on-farm welfare is optimised within each system.

Animal performance and stress at weaning when dairy cows suckle their calves for short versus long daily durations

Calves in most dairy farms are separated from their dams either immediately or within a few hours after birth, prompting increasing concern of the society for reasons of animal welfare. The aim of this study was to identify systems to maintain cow-calf contact (CCC) that balance the benefits for calf growth and health against the negative impacts on sellable milk and stress at weaning. We tested reuniting cows and calves for 20 min before (Before-group) or 2.5 h after (After-group) morning milking (in Trial 1) or for a 9 h period between the morning and evening milkings (Half-day-group, in Trial 2). In Control-groups, calves were separated from their dam at birth and fed with artificial nipple with tank milk provided daily at 13% (Trial 1) and 14% (Trial 2) of their BW. In both trials, each practice was applied on a group of 14 dam–calf pairs (7 Holstein [Ho] and 7 Montbéliarde [Mo]). All calves were weaned at a BW of at least 100 kg. In Trial 1, the After-group was prematurely stopped when the calves were eight weeks of age as calf growth became limited (340 g/d) due to low milk intakes (2.97 kg/d). During the first eight weeks of lactation, milk yield at the parlour was 29%, 51% and 42% lower in After-, Before- and Half-day-cows respectively compared to Controls. From week 14 to 16 when all calves were separated from their dam, Before-cows still produced 25% less milk than Control-cows while Half-day-cows reached the milk yield of Control-cows within a week. There were no significant differences in milk somatic cell count and in frequency of health disorders (cows and calves) between suckling and Control-groups. Compared to Control-calves, calf growth until weaning was higher in the suckling calves in Trial 1 (861 vs 699 g/d) and similar in Trial 2 (943 vs 929 g/d). At weaning, Before- and Half-day-calves started to vocalise earlier and continued to vocalise longer than Controls. In conclusion, the best compromise between cow milk yield and calf growth is a long period of CCC (9 h) between the morning and evening milkings. Still abrupt weaning stresses both cows and calves even if CCC has been restricted before separation.

34 Extended Effects of Sequential Weaning and Backgrounding Management in Beef Calves

Abstract Alternate weaning methods and backgrounding periods are strategies to reduce calf morbidity and mortality at feedlot arrival. The objective of this study was to assess the collective effects of weaning and post-weaning management practices on potential carryover effects on calf health and performance through the backgrounding phase. A total of 216 steer calves (average BW, 298 kg) from three Auburn University research farms were randomly assigned to one of three different weaning method groups: Fenceline weaning, nose-flap weaning, or abrupt weaning. Calves were weighed on d 0 and d 14 post weaning, and then began a 60-d preconditioning period. Calves were randomized according to previous weaning management, farm of origin, and body weight to one of three nutritional management strategies in a 3 ×3 factorial design: cool-season baleage (oats, ryegrass and crimson clover) and 1% BW dried distillers grains (DDGS), bermudagrass hay and 1% BW DDGS, or grazing mixed warm-season annuals and 1% BW DDGS. Calf body weights were collected on d 0, d 30 and d 60 of the backgrounding phase. Weights did not differ during the weaning phase but calves in the fenceline group had the greatest average daily gain (1.13 kg/d; P &amp;lt; 0.0001) during this phase. There was a weaning × backgrounding treatment interaction (P = 0.0097) for average daily gain during the first 30 d of the backgrounding phase. Calves that were fenceline weaned and on the cool season baleage diet had the highest average gain at 1.02 kg/d, whereas abruptly weaned calves on the grazing diet only gained 0.29 kg/d in the first 30 d. Steers on the cool season baleage diet had the greatest total gain (P &amp;lt; 0.0001) at 45.8 kg over the course of the 60-d period. These results indicate that backgrounding diet, coupled with weaning management strategies, may influence calf performance during the transition period for calves into the post-weaning phase.

The adoption of good practices of handling improves dairy calves welfare: Case study

The aim of this study was to assess the effect of the adoption of a set of good practices of handling on dairy calves welfare. Data were retrieved from the records of a commercial farm, considering three periods: Conventional handling (CH, 12 mo.), transitional period (TP, 4 mo.), and good practices handling (GPH, 12 mo.). During CH calves were kept in individual pens, milk-fed in open pails and subjected to abrupt weaning; while during TP and GPH they were kept in groups, milk-fed in nipple-pails, brushed for 5 min. once a day, and subjected to progressive weaning. TP was assumed as a training period necessary for GPH implementation. The percentages of calves treated with antibiotics and numbers of deaths per month were used as indicators of calves welfare. Statistical analysis was performed using a logistic regression model to compare the number of deaths per month between CH and the other periods. Chi-square test was used to compare the percentage of animals treated with antibiotics per month. Results showed that CH had a higher risk of calf's death then TP and GPH, as well as a higher percentage of animals treated with antibiotics. In conclusion, the adoption of good practices of handling improved dairy calves welfare.

Intranasal oxytocin treatment on the day of weaning does not decrease walking behavior or improve plasma metabolites in beef calves placed on pasture

The purpose of this study was to evaluate the effect of intranasal oxytocin administered at abrupt weaning on weaning behaviors such as walking distance and time devoted to walking, calf body weight, and plasma non-esterified fatty acids (NEFAs), β-hydroxybutyrate (β-HB), and cortisol. Twenty Simmental × Angus heifer calves were randomly assigned to one of two treatments: intranasal oxytocin (OXT; n = 10) or intranasal saline (CON; n = 10). All calves were given the respective intranasal treatment on the day of weaning (day 0) and then placed on pasture together. Calves were weighed and a blood sample was obtained on days 0, 1, 7, and 14 postweaning. Blood samples were subsequently used to quantify plasma NEFA, β-HB, and cortisol concentrations. All calves in both treatment groups were fitted with an individual global positioning system that recorded calf location every 10 s for a 16-h period on days 0, 7, and 14 to quantify and evaluate walking behaviors. There was no treatment × day effect for distance walked (P = 0.82), walking time (P = 0.80), non-walking time (P = 0.88), area utilization index (P = 0.84), calf body weight (P = 0.82), average daily gain (P = 0.54), NEFA (P = 0.22), or cortisol concentrations (P = 0.32). There was a tendency for a treatment × day effect observed for average walking speed (P = 0.09) and β-HB (P = 0.10), such that calves in the CON treatment tended to have lesser average walking speeds on day 14 and tended to have greater β-HB concentration after weaning. There was a treatment effect (P = 0.02) for NEFA concentrations, with the CON calves having a greater plasma NEFA concentration throughout the study compared with OXT calves. These data imply that OXT calves may have had differing metabolic responses immediately after weaning that could have altered the mobilization of NEFA, but this change was not substantial enough to impact body weights or walking behaviors.

Effects of weaning on survival and growth of silver therapon ( Leiopotherapon plumbeus ) larvae fed live and artificial diet

This study examined the effects of early weaning strategies on growth and survival of the silver therapon Leiopotherapon plumbeus larvae. In Trial 1, four larval age groups (8, 14, 20 and 26 days post-hatch (dph)) were abruptly weaned to commercial powdered tilapia diet and compared with wild copepod-fed group as the control. In Trial 2, another batch of three weaning age groups were subjected to gradual weaning (8 dph larvae with 8 days co-feeding, 14 dph larvae with 6 days co-feeding and 20 dph larvae with 4 days co-feeding) with Artemia nauplii prior to weaning on commercial powdered prawn diet and compared with a control group consisted of larvae fed exclusively on Artemia nauplii. Both weaning trials were conducted for 21 days. A gradual weaning strategy promoted better survival (22.2%–40.0%) among weaning age groups than the abrupt weaning strategy (2.2%–36.7%). Except for those weaned at 26 dph, abrupt weaning resulted in significantly poor growth and survival among all weaning age groups compared with the wild copepod-fed control group. The highest survival and growth were observed in 20 dph larvae with 4 days live food co-feeding, although the values were significantly lower than the Artemia-fed control group. These results suggest that abrupt weaning at 26 dph, and gradual weaning for 4 days from 20 dph promote successful rearing of silver therapon larvae and that a microparticulate diet specifically formulated for this species needs to be developed.

Effects of 25-hydroxyvitamin D3 on growth performance, fecal scores, vitamin D3 metabolites, antioxidant status, and inflammatory and stress-related parameters in weaning calves

The objectives of this study were to evaluate the effects of milk replacers containing 25-hydroxyvitamin D3 [25(OH)D3] and enriched with vitamin D3 on the growth performance, fecal scores, vitamin D3 metabolites, biochemical blood parameters and antioxidant, inflammatory and stress-related parameters of Holstein male calves. Thirty Holstein male calves (body weight = 41.4 ± 2.79 kg) were randomly assigned to three groups for a 56-day experimental period. The control group received milk replacer containing 1.2 mg/kg vitamin D3, the VD group received milk replacer containing 13.2 mg/kg vitamin D3, and the 25D group received milk replacer containing 300 mg/kg 25(OH)D3 plus 1.2 mg/kg vitamin D3 until weaning at day 54. On days 52, 57 and 59, which were defined as days -2, 3 and 5 postweaning, blood samples were collected to measure biochemical blood parameters and antioxidant, inflammatory and stress-related indicators. Calves that received milk replacer containing 25(OH)D3 consumed more calf starter at one week postweaning (P < 0.01) than those in the control and VD groups. Calves in the VD and 25D groups had a significantly (P = 0.02) greater ADG than calves in control during the overall period. Calves in the VD and 25D groups had greater body weight and withers height on day 60 than calves in the control group. Calves fed 25(OH)D3 displayed lower fecal scores and incidence of fecal scores > 2 overall periods. Calves fed 25(OH)D3 had increased serum 25(OH)D3 during the preweaning (P < 0.0001) and postweaning (P < 0.0001) periods. A treatment × time interaction (P < 0.0001) was detected for serum vitamin D3 and 25(OH)D3 in preweaning calves, however, there was no significant time effect on serum vitamin D3 and 25(OH)D3 during the weaning period. Abrupt weaning increased concentrations of total protein, glucose, cholesterol, tCa and tP. Calves fed 25(OH)D3 had a higher tCa (P = 0.04) and tP (P = 0.02) concentrations than those fed other diets. Weaning challenge significantly decreased the CAT concentration and increased the MDA concentration, and calves fed 25(OH)D3 displayed higher GSH-Px and CAT and lower MDA concentrations during the weaning period. Weaning also significantly increased the cytokine contents, including IL-1β, IL-6 and TNF-α, and stress indicators, including cortisol and haptoglobin. Significantly lower cytokine (IL-6 and TNF-α) and stress indicator (cortisol and haptoglobin) contents were observed in calves fed 25(OH)D3 than in those from the VD and control groups at 3 and 5 DPW, respectively. In conclusion, feeding milk replacer with 25(OH)D3 had the potential to improve the growth performance, fecal scores, serum 25(OH)D3, and tCa and tP concentrations of calves, and may reduce weaning stress by enhancing the antioxidant capacity and decreasing the proinflammatory and stress indicators of calves.

Effect of three weaning methods on behavioural, cortisol and weight changes in buffalo calves

Context Calves reared in cow–calf systems separated from their mothers could present various physiological and behavioural changes. Aims The objective of the present study was to examine the effect of different weaning protocols on plasma cortisol concentrations, behavioural responses, and weight gain in water buffalo calves. Methods In total, 40 Murrah buffalo calves (20 males, 20 females) aged 7–8 months and weighing 247.05 ± 33.23 kg were included. The animals were assigned to one of four treatments (10 per group, 5 males, 5 females), as follows: non-weaned calves (NoW); calves weaned abruptly on Day 0 (AW); calves fitted with nose-flaps anti-suckling devices on Day –7 and completely separated from their mothers on Day 0 (NFW); and calves separated from their mothers by a fence line on Day –7 and, then completely separated from their mothers on Day 0 (FENW). Plasma cortisol was measured on Days –7, –6, –4, 0, 1 and 3, while the behavioural variables were measured from Day –7 to Day –4, and from Day 0 to Day 3. The weight of the calves was evaluated on Days –9, –7, 0 and 3. Key results AW calves presented higher cortisol concentrations than did NoW calves (P = 0.0002) and showed a marked increase in walking and decrease in grazing and ruminating on Days 0–3 compared with the other treatments (P &lt; 0.0001). The use of NFW caused behavioural changes after the device placement and after the final separation from the mother (P &lt; 0.0001). In FENW, behavioural changes were observed after the separation by a linear fence but no negative changes were observed after the final separation from the mothers, and positive behaviours such as grazing, rumination and exploration increased. No changes in weight gain were observed (P &gt; 0.05). Conclusions No clear effects were observed in the implementation of alternative weaning, since both NFW and FENW presented changes related to stress at weaning, compared with abrupt weaning. However, in FENW, no behavioural alterations were observed after definitive separation from their mothers. Implications The application of fence-line separation before final separation could be a promising strategy to reduce stress at weaning in water buffalo calves. However, further studies are required to determinate its long-term effect.

Influence of weaning strategy on behavior, humoral indicators of stress, growth, and carcass characteristics.

Weaning is one of the most stressful events a calf experiences in our current beef production system. Its effects may include reduced feed intake, increased activity, slower growth, and increased susceptibility to disease. This study was designed to evaluate weaning after a 7-d placement of nose flaps at 7 mo (N, n = 40) and delaying weaning by 49 d relative to 7-mo weaning (D, n = 39) as alternatives to the industry standard; abrupt weaning at 7 mo of age (A, n = 39). The 4-yr trial utilized Angus and Angus X Senepol steer calves. Calves were randomly assigned to weaning strategy after being stratified by dam parity (heifer/cow), hair coat phenotype (normal/slick), and body weight. Behavioral observations were made on five steers per strategy group per year over the weeks surrounding weaning. Activity levels were determined by accelerometers worn on neck collars. Blood samples were obtained from the observed cattle during the last 2 yr to determine haptoglobin and cortisol concentration. Once weaned, the steers were followed through finishing and carcass characteristics obtained at harvest. Twelve of 38 steers in the N group had sores in their nostrils from the nose flaps when the flaps were removed at weaning of A/N (237 ± 3 d of age). The A and D calves were more active than N calves in the first 2 to 3 d after weaning but settled down to similar activity levels to N by the day 4. The A and D groups were more vocal than N during the same time frame. Cortisol and haptoglobin remained within normal reference ranges. Average daily body weight gain (ADG) was greater for D than A, who in turn had greater ADG than N during the first 42 d after A and N calves were weaned (0.69, 0.54, and 0.37 kg/d for D, A, and N, respectively; P < 0.01). All treatment groups graded Low Choice at harvest and exhibited similar efficiency of gain during growth and finishing (P > 0.2). Based on ADG during the 42 d after weaning, we recommend delaying weaning when available pasture and cow body condition support this strategy. When conditions do not permit delayed weaning, abrupt weaning may be the next viable option based on animal welfare concerns and increased handling to place and remove the flaps. Nose flaps reduced vocalization at weaning but resulted in less postweaning ADG. Based on our data, we suggest that abrupt weaning under the conditions of this study, is less stressful than we perceive it to be, based on calf behavior.

The effect of genotype and sex on growth and carcass traits of lambs

Submitted 2020-07-24 | Accepted 2020-08-31 | Available 2020-12-01 https://doi.org/10.15414/afz.2020.23.mi-fpap.276-281 The objective of the present study was to investigate the effect of genotype and sex on growth and carcass traits of grazing lambs. A total of 32 lambs (16 Improved Jezersko-Solcava - JSR and 16 crossbreds with Texel - JSRT, 8 males and 8 females within each genotype) were included in the study. The lambs were grazed together with their dams from the beginning of the grazing period and had free access to commercial concentrate from the age of 10 days. Lambs were weaned at the average body weight of 22.9 kg. Feeding with a concentrate was finished when lambs achieved 35 kg of body weight and were slaughtered. Daily gains from birth to slaughter and from weaning to slaughter were calculated. Several carcass traits were determined. JSRT lambs had significantly higher daily gain from birth to slaughter, hot and cold carcass weights, and dressing percentages compared to JSR lambs. Carcass conformation was higher in JSRT than JSR carcasses. Also, carcasses of JSRT were shorter and wider than JSR carcasses. Rib eye muscle areas of JSRT lambs were significantly larger, and the colour was significantly lighter. Males had significantly higher average daily gain from birth to slaughter and from weaning to slaughter than females. Females had higher dressing percentages and subcutaneous and internal fatness scores than males. Females had significantly higher amount of kidney fat. The colour of males’ meat was significantly lighter than that of females. Crossbreeding with Texel rams improved growth and carcass traits of lambs, and males had better growth performance and several carcass traits than females. Keywords: lambs, commercial crossbreeding, sex, growth, carcass trait References Blasco, M. et al. (2019). Effect of Texel crossbreeding on productive traits, carcass and meat quality of Segurena lambs. Journal of the Science of Food and Agriculture, 99, 3335-3342. https://doi.org/10.1002/jsfa.9549 Cardoso, M. T. M. et al. (2013). Performance and carcass quality in three genetic groups of sheep in Brazil. Revista Brasileira de Zootecnia, 42(10), 734-742. https://doi.org/10.1590/S1516-35982013001000007 Claffey, N. A. et al. (2018). Effect of breed and castration on production and carcass traits of male lambs following an intensive finishing period. Translational Animal Science, 2, 407-418. https://doi.org/10.1093/tas/txy070 Do Prado Paim, T. et al. (2013). Performance, survivability and carcass traits of crossbred lambs from five paternal breeds with local hair breed Santa Ines ewes. Small Ruminant Research, 112, 28-34. https://doi.org/10.1016/j.smallrumres.2012.12.024 Facciolongo, A. M. et al. (2018). Effect of diet lipid source (linseed vs. soybean) and gender on performance, meat quality and intramuscular fatty acid composition in fattening lambs. Small Ruminant Research, 159, 11-17. https://doi.org/10.1016/j.smallrumres.2017.11.015 Freitas-de-Melo, A. et al. (2019). Behavioral pattern in Texel x Corriedale terminal crossbreeding: Maternal behavior score at birth, lambs’ feeding behaviors, and behavioral responses of lambs to abrupt weaning. Journal of Veterinary Behavior, 30, 9-15. https://doi.org/10.1016/j.jveb.2018.10.007 Nunes, I. A. et al. (2019). Performance, carcass characteristics, and centesimal composition of meat from Santa Ines lambs and Texel crossbred lambs (Santa Ines × Texel). Canadian Journal of Animal Science, 99(2), 228-236. https://doi.org/10.1139/cjas-2016-0231 Perez, P. et al. (2007). Gender and slaughter weight effects on carcass quality traits of suckling lambs from four different genotypes. Small Ruminant Research, 70, 124-130. https://doi.org/10.1016/j.smallrumres.2006.01.013 SAS. (2014). SAS/STAT® 13.2 User’s Guide. SAS Institute Inc., Cary, NC, USA. Scales, G. H. et al. (2000). Effect of sire breed on growth, carcass, and wool characteristics of lambs born to Merino ewes in New Zealand. New Zealand Journal of Agricultural Research, 43(1), 93-100. https://doi.org/10.1080/00288233.2000.9513412

120 Performance Effects on Weaned Calves using 3 Weaning Strategies and Nutritional Supplementation

Abstract The objective of this study was to compare nutritional and management strategies on performance of beef calves at weaning. Forty crossbred beef calves were assigned to receive either nutritional supplementation (Drench) 3 wks prior to weaning and again at weaning or nothing (Cntrl). In addition, calves were assigned 1 of 3 weaning treatments: 1) abrupt weaning with complete separation (Abrupt); 2) 4d fence line weaning with cows allowed to interact with calves through a fence for 4 d before removal (4Fence); and 3) 7 d fence line weaning with cows allowed to interact with calves through a fence for 7 d before removal (7Fence). Calves were blocked by sex and BW. Nutritional supplementation consisted of an oral drench (5cc/100 lbs. BW; Cellarator Turbo Drench; ADM Animal Nutrition; Quincy, IL). Calves were weighed at weaning, 7 d after, and 85 d after weaning. At weaning, average age of calves was 213 ± 19 d and average weight 224 ± 30 kg. Average final weight of calves was 279 ± 33 kg. Weight differences between weaning and 7 d after weaning and weaning and 85 d after weaning were analyzed using Proc Mixed with nutritional supplementation, sex, and weaning duration as fixed variables. Calves receiving Drench gained more (P &amp;lt; 0.05) 1 wk after weaning (7.9 vs. 3.7 kg, respectively). Weight gains 85 d after weaning were not different (P &amp;gt; 0.05) 7 d after weaning. Weight gain in calves assigned to 4Fence and 7Fence treatments were not different (P &amp;lt; 0.05) but gained more (P &amp;lt; 0.05) than Abrupt calves (8.5 vs. 7.6 vs. 1.2 kg, respectively). Weight gains 85 d after weaning were not different (P &amp;gt; 0.05) between weaning treatments. In conclusion, nutritional supplementation and fence-line weaning improved calf performance 1 wk after weaning but not after 3 mo.