Exploration of early social behaviors and social styles in relation to individual characteristics in suckling piglets.

Social behavior is a key component of pig welfare on farms, but little is known on the development of social behaviors in piglets. This study aimed to explore social behaviors and identify early social styles in suckling piglets. Social behaviors of 68 piglets from 12 litters were scored continuously for 8 h per day at 21 and 42 days of age, and were included in a Hierarchical Clustering on Principal Components analysis to identify clusters of pigs with similar social styles. Social nosing represented 78% of all social interactions given. Three social styles were identified: low-solicited inactive animals (inactive), active animals (active), and highly-solicited avoiders (avoiders). Belonging to a cluster was independent of age, but was influenced by sex, with females being more represented in the 'inactive' cluster, and males in the 'active' cluster, whereas both sexes were equally represented in the 'avoider' cluster. Stability of piglets' allocation to specific clusters over age was high in the 'inactive' (59%) and 'active' (65%) clusters, but low in the 'avoider' cluster (7%). Haptoglobin and growth rate were higher in 'active' than 'inactive' pigs, and intermediate in 'avoiders'. Our findings suggest the existence of transient social styles in piglets, likely reflective of sexual dimorphism or health status.

Investigating cow-calf contact in a cow-driven system: performance of cow and calf.

In this research communication we describe the performance of dairy cow-calf pairs in two cow-driven CCC-systems differing in cows' access to the calves through computer-controlled access gates (smart gates, SG). We investigated cows' machine milk yield in the automatic milking system (AMS), calf growth, and intake of supplemental milk and concentrate. Two groups each with four cow-calf pairs were housed in a system with a cow area, a calf creep and a meeting area. SG's controlled cow traffic between the meeting area and the cow area where cows could obtain feed, cubicles and the AMS. Calves had ad libitum access to supplemental milk and concentrate. During the suckling phase of 31 d, cow access to the meeting area was free 24 h/d (group 1) or restricted (group 2) based on milking permission. Following the suckling phase, cow access was gradually decreased over 9 d (separation phase). During the suckling phase, cows' machine milk yield (mean ± sd) in the AMS was 11.4 ± 6.38 kg/d. In the separation phase, the yield increased to 25.0 ± 10.37 kg/d. Calf average daily gain (ADG) was high during the suckling phase: 1.2 ± 0.74 kg. During the separation phase, ADG decreased to 0.4 ± 0.72 kg which may be related to a low intake of supplemental milk. Calves' concentrate intake increased with age, and all calves consumed >1 kg/d after separation. We conclude that cows nurse the calf in a cow-directed CCC system well resulting in high ADG, and AMS milk yields were, at least, partially maintained during the suckling phase. Although the AMS yields increased in response to separation, calf ADG was decreased. A low sample size limits interpretation beyond description but provides a basis for hypotheses regarding future research into CCC-systems.

Effects of Early Transplantation of the Faecal Microbiota from Tibetan Pigs on the Gut Development of DSS-Challenged Piglets.

The present study was conducted to investigate the effects of early transplantation of the faecal microbiota from Tibetan pigs on the gut development of dextran sulphate sodium- (DSS-) challenged piglets. In total, 24 3-day-old DLY piglets were divided into four groups (n = 6 per group); a 2 × 2 factorial arrangement was used, which included faecal microbiota transplantation (FMT) (from Tibetan pigs) and DSS challenge. The whole trial lasted for 55 days. DSS infusion increased the intestinal density, serum diamine oxidase (DAO) activity, and colonic Escherichia coli count (P < 0.05), and decreased the Lactobacillus spp. count and mRNA abundances of epidermal growth factor (EGF), glucagon-like peptide-2 (GLP-2), insulin-like growth factor 1 (IGF-1), occludin, mucin 2 (MUC2), regeneration protein IIIγ (RegIIIγ), and interleukin-10 (IL-10) in the colon (P < 0.05). FMT increased the Lactobacillus spp. count and mRNA abundances of GLP-2, RegIIIγ, and IL-10 in the colon (P < 0.05), and decreased the intestinal density, serum DAO activity, and colonic E. coli number (P < 0.05). In addition, in DSS-challenged piglets, FMT decreased the disease activity index (P < 0.05) and attenuated the effect of DSS challenge on the intestinal density, serum DAO activity, and colonic E. coli number (P < 0.05). These data indicated that the faecal microbiota from Tibetan pigs could attenuate the negative effect of DSS challenge on the gut development of piglets.

Desenvolvimento ponderal e parâmetros hematológicos e bioquímicos de cordeiros Pantaneiros submetidos a diferentes manejos de amamentação / [Ponderal development and hematological and biochemical parameters of Pantaneiro lambs subjected to different suckling regimens]

Este estudo teve por objetivo avaliar o desenvolvimento ponderal e a dinâmica dos parâmetros hematológicos e bioquímicos de cordeiros Pantaneiros submetidos a diferentes manejos de amamentação dos 15 aos 43 dias. Foram separados 30 cordeiros em três diferentes grupos (n=10). Os grupos foram caracterizados conforme o tempo de permanência das ovelhas com suas crias em diferentes sistemas de amamentação: MAM24 - ovelhas e cordeiros 24 horas em conjunto; MAM12 - ovelhas e cordeiros 12 horas em conjunto durante a noite; MAM2x30 - ovelhas e cordeiros 30 minutos de manhã e 30 minutos à tarde em conjunto. As coletas de amostras sanguíneas e as pesagens ocorriam a cada sete dias. Houve aumento significativo no peso com o avanço da idade dos cordeiros nos três manejos, mas os tratamentos não diferiram entre si para o ganho de peso. Houve diferenças entre os três tratamentos para a variável hematológica CHGM e para as variáveis bioquímicas AST, glicose, ureia e proteína total. As variáveis bioquímicas foram influenciadas pela faixa etária dos animais. Os diferentes manejos de amamentação não influenciaram o desenvolvimento ponderal dos cordeiros. Não ocorreram alterações patológicas. Alguns parâmetros hematológicos e bioquímicos podem ser influenciados pelo desenvolvimento etário dos cordeiros.(AU)

This study aimed to evaluate the weight development and the dynamics of hematological and biochemical parameters of Pantaneiro lambs submitted to different breastfeeding management from 15 to 43 days. First, 30 lambs were separated into three different groups (n = 10). The groups were characterized according to the length of stay of ewes with their young in different breastfeeding systems: MAM24 - ewes and lambs 24 hours together. MAM12- Sheep and lambs 12 hours together at night. MAM2x30 - sheep and lambs 30 minutes in the morning and 30 minutes in the afternoon together. Blood samples were collected and weighed every seven days. Significant increase in weight was observed with the age of the lambs in the three managements, but the treatments did not differ for weight gain. Differences were identified between the three treatments for the hematological variable CHGM and for the biochemical variables AST, glucose, urea and total protein. Correlating the age of the lambs with the biochemical variables, there was variation influenced by the age of the animals. The different management of breastfeeding did not influence the weight development of the lambs. Hematological and biochemical variations did not represent pathological changes. Some hematological and biochemical parameters may be influenced by the age development of lambs.(AU)

Perinatal Docosahexaenoic Acid Supplementation Improves Cognition and Alters Brain Functional Organization in Piglets.

Epidemiologic studies associate maternal docosahexaenoic acid (DHA)/DHA-containing seafood intake with enhanced cognitive development; although, it should be noted that interventional trials show inconsistent findings. We examined perinatal DHA supplementation on cognitive performance, brain anatomical and functional organization, and the brain monoamine neurotransmitter status of offspring using a piglet model. Sows were fed a control (CON) or a diet containing DHA (DHA) from late gestation throughout lactation. Piglets underwent an open field test (OFT), an object recognition test (ORT), and magnetic resonance imaging (MRI) to acquire anatomical, diffusion tensor imaging (DTI), and resting-state functional MRI (rs-fMRI) at weaning. Piglets from DHA-fed sows spent 95% more time sniffing the walls than CON in OFT and exhibited an elevated interest in the novel object in ORT, while CON piglets demonstrated no preference. Maternal DHA supplementation increased fiber length and tended to increase fractional anisotropy in the hippocampus of offspring than CON. DHA piglets exhibited increased functional connectivity in the cerebellar, visual, and default mode network and decreased activity in executive control and sensorimotor network compared to CON. The brain monoamine neurotransmitter levels did not differ in healthy offspring. Perinatal DHA supplementation may increase exploratory behaviors, improve recognition memory, enhance fiber tract integrity, and alter brain functional organization in offspring at weaning.

Age and calving time affects production efficiency of beef cows and their calves.

The aim of this study was to evaluate the influence of two sub-periods of the calving season and two cow maturity stages on the efficiency of beef cows and their calves. A total of 159 cow-calf pairs were divided by calving time (early or late) within the calving season and maturity stage (young or adult). Calves were weaned at 42 or 63 days after birth and evaluated until 210 days of age. Cows and calves had their development examined based on their weight and body condition score at calving, at weaning, and at 210 days. Reproductive performance was evaluated on the basis of time to become pregnant again. Milk yield was assessed by the direct method on three occasions spaced 21 days apart. Adult cows were heavier than young cows, at calving (398.5 vs 327.5 kg, respectively), weaning (397.3 vs 324.1 kg, respectively) at the end breeding season (424.1 vs 342.1 kg, respectively). Reproductive performance was influenced by calving time. Adult cows had higher pregnancy rates (83.75 and 69.17%, for early and for late calving, respectively) than young cows (57.03 and 35.01% for early and for late-calving, respectively). Calves from early-calving young cows weighed 158.8 kg at 210 days of age vs. 123.7 kg for those born from late-calving adult cows. However, late-calving cows produced 10.7% more milk than those that calved early in the season (227.0 vs 205.0 liters, respectively). Early calving associated with non-requirement of growth determine higher productivity efficiency in beef cows.

Feed intake of the sow and playful creep feeding of piglets influence piglet behaviour and performance before and after weaning.

Creep feed intake is variable and may be partly homeostatically and exploratory driven. We studied effects of maternal feed restriction and a 'play-feeder' on piglet behaviour and performance. 37 Litters received creep feed in a conventional (CON) or play-feeder (PL) and their sows were full-fed (FF) or restrictedly-fed (RES). Eaters were determined via rectal swabs. At weaning (d24) four piglets from the same treatment were grouped (n = 36 pens). RES hindered piglet growth by 41 g/d and enhanced time eating, creep feed intake and percentage of eaters at weaning versus FF. RES-PL had the largest proportion of moderate and good eaters. PL stimulated feeder exploration and attracted more piglets to the feeder than CON. Post-weaning, RES increased exploratory behaviours, feed intake between d0-5, and growth between d0-2, and reduced body lesions between d0-2 (within CON), drinking and ear biting. PL increased ingestive behaviours, feed intake and growth between d0-15, and BW at d15 post-weaning by 5%. PL also lowered the prevalence of watery diarrhoea, number of body lesions and piglets with ear (within FF) and tail (within RES) damage at d15 post-weaning. Treatments did not affect FCR. To conclude, RES and particularly PL (broader and for longer) result in less weaning-associated-problems.

Dietary iron chelate for sows and effects on iron supplementation in piglets.

In order to evaluate iron chelate in diets for sows during gestation and lactation and its effects on iron supplementation for piglets, a total of 50 pregnant sows in the third parity order were distributed according to a randomized block design with two treatments: diet without iron chelate supplementation (n=20); diet supplemented with 0.15% of iron chelate (n=30). The litters of sows were distributed into five different treatments: sows without iron chelate supplementation and piglets receiving intramuscular iron-dextran; sows without iron chelate supplementation and piglets receiving oral iron supplementation; sows supplemented with iron chelate and piglets receiving intramuscular iron-dextran; sows supplemented with iron chelate and piglets receiving oral iron supplementation; sows supplemented with iron chelate and piglets without iron supplementation. No influence of dietary supplementation of iron chelate was verified on the productive parameters of the sows. For the piglets, iron-dextran supplementation promoted higher weaning weight in comparison to non-supplemented piglets, although not differing to those received oral iron supplementation. Thus, iron chelate supplementation did not improve the productive parameters of sows, but it increased iron excretion in the feces, thus requiring iron supplementation for the piglets after birth.

Lipidome profiles of postnatal day 2 vaginal swabs reflect fat composition of gilt's postnatal diet.

We hypothesized that postnatal development of the vagina is impacted by early nutritional environment. Our objective was to determine if lipid profiles of vaginal swabs were different between postnatal gilts suckled by sow or fed milk replacer the first 48 h after birth, with or without a lard-based fat supplement. Gilts (>1.3 kg) were selected at birth across 8 litters and assigned to one of four treatments: 1) suckled by sow (S, n = 8); 2) suckled by sow plus administration of a fat supplement (SF, n = 5); 3) bottle-fed solely milk replacer (B, n = 8); or 4) bottle-fed solely milk replacer plus administration of a fat supplement (BF, n = 7). At 48 h postnatal, vaginal swabs of gilts were taken with a cytology brush, and lipids were extracted for analysis using multiple reaction monitoring (MRM)-profiling. Lipids extracted from serum collected at 48 h from gilts, milk collected at 24 h from sows, and milk replacer were also analyzed with MRM-profiling. Receiver operating characteristic curve analysis found 18 lipids recovered from vaginal swabs that highly distinguished between S and B gilts [area-under-the-curve (AUC) > 0.9], including phosphatidylethanolamine with 34 carbons and four unsaturations in the fatty acyl residues [PE (34:4)]. Twelve lipids from vaginal swabs highly correlated (r > 0.6; p < 0.01) with nutrition source. Lipids with greater abundance in milk replacer drove association. For example, mean intensity of PE (34:4) was 149-fold higher in milk replacer than colostrum. Consequently, PE (34:4) was found to have 1.6- and 2.12-fold higher levels in serum and vaginal swab samples (p < 0.001), respectively, of B gilts as compared to S gilts. Findings support that vaginal swabs can be used to noninvasively study effects of perinatal nutrition on tissue composition.

High oxytocin infants gain more mass with no additional maternal energetic costs in wild grey seals (Halichoerus grypus).

Maximising infant survival requires secure attachments and appropriate behaviours between parents and offspring. Oxytocin is vital for parent-offspring bonding and behaviour. It also modulates energetic balance and neural pathways regulating feeding. However, to date the connections between these two areas of the hormone's functionality are poorly defined. We demonstrate that grey seal (Halichoerus grypus) mothers with high oxytocin levels produce pups with high oxytocin levels throughout lactation, and show for the first time a link between endogenous infant oxytocin levels and rates of mass gain prior to weaning. High oxytocin infants gained mass at a greater rate without additional energetic cost to their mothers. Increased mass gain in infants was not due to increased nursing, and there was no link between maternal mass loss rates and plasma oxytocin concentrations. Increased mass gain rates within high oxytocin infants may be due to changes in individual behaviour and energy expenditure or oxytocin impacting on tissue formation. Infancy is a crucial time for growth and development, and our findings connect the oxytocin driven mechanisms for parent-infant bonding with the energetics underlying parental care. Our study demonstrates that oxytocin release may connect optimal parental or social environments with direct physiological advantages for individual development.

Effects of maternal alpha-ketoglutarate supplementation during lactation on the performance of lactating sows and suckling piglets.

The aim of the study was to investigate if dietary alpha-ketoglutarate (AKG) supplementation may improve the performance of lactating sows and their suckling piglets. After farrowing, 24 lactating sows (Large White × Landrace) with similar body weight (BW) were assigned to the control and AKG groups based on parity, and their lactation diets were supplemented with 0.00 or 0.25% AKG, respectively. It was found that supplementing the diet of lactating sows with 0.25% AKG enhanced growth performance of the suckling piglets from d 7 to d 21 of the lactation period, improved villus height of ileum and tended (p = 0.085) to increase mean volumetric bone mineral density of femur in the weanling piglets. In the lactating sows, dietary supplementation of AKG decreased plasma urea level on d 14 of lactation, decreased plasma calcium (Ca) concentrations from d 7 to d 21 of lactation and increased lactose and Ca levels in ordinary milk. Thus, it was proposed that AKG supplementation stimulates the capacity for lactose synthesis and Ca uptake in the mammary gland, thereby altering the composition of the ordinary milk which might be associated with the enhanced performance of piglets during the suckling period. These findings could lead to a better application of AKG in lactating nutrition, and therefore, promoting pork production.

Invited review: A systematic review of the effects of prolonged cow-calf contact on behavior, welfare, and productivity.

Separation of calves from cows within hours or days of birth is common on dairy farms. Stakeholders have conflicting perspectives on whether this practice is harmful or beneficial for the animals' welfare and production. Our objective was to critically evaluate the scientific evidence for both acute and long-term effects of early separation versus an extended period of cow-calf contact. The outcomes investigated were the behavior, welfare (excluding physical health), and performance (milk yield and growth, respectively) of dairy cows and calves. Primary research papers were found through targeted Web of Science searches, the reference lists of recent reviews for each topic, and the reference lists of papers identified from these sources. Studies were included if they were published in English, the full text was accessible, and they compared treatments with and without contact between dairy cows and calves for a specified period. Early separation (within 24 h postpartum) was found to reduce acute distress responses of cows and calves. However, longer cow-calf contact typically had positive longer-term effects on calves, promoting more normal social behavior, reducing abnormal behavior, and sometimes reducing responses to stressors. In terms of productivity, allowing cows to nurse calves generally decreased the volume of milk available for sale during the nursing period, but we found no consistent evidence of reduced milk production over a longer period. Allowing a prolonged period of nursing increased calf weight gains during the milk-feeding period. In summary, extended cow-calf contact aggravates the acute distress responses and reduces the amount of saleable milk while the calves are suckling, but it can have positive effects on behaviors relevant to welfare in the longer term and benefit calf growth. The strength of these conclusions is limited, however, given that relatively few studies address most of these effects and that experimental design including timing of contact and observations are often inconsistent across studies. Few studies presented indicators of long-term welfare effects other than abnormal and social behavior of the calves.

Invited review: A systematic review of the effects of early separation on dairy cow and calf health.

Concern from the public is growing regarding early cow-calf separation, yet proponents of this practice maintain that artificial rearing is critical for cow and calf health. Early separation is assumed to reduce the risk of transfer of pathogens from dam to neonatal calf, but a wide range of health benefits associated with extended cow-calf contact has also been documented. The aim of this systematic review was to report and synthesize conclusions from the literature on dairy cow and calf health in conventional rearing versus cow-calf contact systems. Peer-reviewed, published manuscripts, written in English, directly comparing dairy cow or calf health in artificial versus suckling systems, were eligible for inclusion. We conducted 7 targeted searches using Web of Science to identify key literature on important health conditions. The resulting manuscripts underwent a 4-step appraisal process, and further manuscripts were sourced from reference lists. This process resulted in a final sample of 70 articles that addressed cow and calf health. Sufficient literature was available to assess mastitis in cows, and scours, cryptosporidiosis, Johne's disease, pneumonia, immunity, and mortality in calves. The results for cryptosporidiosis, pneumonia, immunity, and mortality were mixed, with some differences between studies likely attributable to flawed comparisons between cohorts. Overall, the articles addressing calf scours and mastitis pointed to beneficial or no effects of suckling. The studies addressing Johne's disease did not find cow-calf contact to be a significant risk factor. In conclusion, the scientific peer-reviewed literature on cow and calf health provides no consistent evidence in support of early separation.

Effect of the rearing system on financial returns from Murciano-Granadina breed goats.

In dairy goats, the kid rearing system can have critical importance in financial returns. Commonly used criteria for the choice of rearing system are not always clear due to the high number of factors involved. The aim of this study was to quantify all those factors to facilitate decision making. So, the effect of two different kid rearing systems, mixed rearing system (MRS) and artificial rearing system (ARS), on milk yield, milk composition and somatic cell count (SCC), milk yield loss at weaning for MRS, kid growth and costs of the different traits on the financial returns in Murciano-Granadina breed goats was studied. Twenty-four goats per group were used. In the MRS, goats reared only one kid, which had free access to goat milk 24 h a day and were weaned at week 6 of lactation, whereas kids in the ARS were separated from their mothers at kidding, colostrum and artificially reared. In both systems, dams were machine-milked once a day throughout lactation and the records took place weekly. Potential milk yield was estimated according to the oxytocin method up to week 12 of lactation, and was similar for both rearing systems, although a 12.3% drop in potential milk yield at weaning was observed for MRS. During the first 6 weeks of lactation, marketable milk was lower for dams in MRS compared to those in ARS (72.1 v. 113.0 l), but similar for the rest of the experiment (101.5 v. 99.4 l, respectively). Marketable milk composition and SCC throughout the 12 weeks of lactation were unaffected by the rearing system. Artificial rearing system entailed an increment in production cost of 22.2€ per kid compared to the rearing by MRS. A similar economic return per goat and kid was obtained from ARS and MRS in this experiment, although, due to one herd's prolificacy of 1.8, the actual results would be 16.2€ per goat in favour of MRS. The real interest of this experiment may be the possibility of extrapolation to different flocks with diverse levels of milk production, prolificacy and prices and costs for incomes and outputs, to estimate the production system that increases returns. In conclusion, the results showed an increase in the cost of €22.2 per kid bred in the ARS, compared to the MRS, and a final return of 16.2€ per goat in favour of the mixed system.

Nurse sow strategies in the domestic pig: II. Consequences for piglet growth, suckling behaviour and sow nursing behaviour.

Nurse sow strategies are used to manage large litters on commercial pig farms. However, new-born piglets transferred to nurse sows in late lactation might be compromised in terms of growth and survival. We investigated the effects of two nurse sow strategies on piglet growth, suckling behaviour and sow nursing behaviour. At 1-day post-farrowing, the four heaviest piglets from large litters were transferred to a nurse sow either 21 (1STEP21, n=9 litters) or 7 (2STEP7, n=10 litters) days into lactation. The remainder of the litter remained with their mother and was either kept intact (remain intact (RI), n=10 litters) or had some piglets cross-fostered to equalise birth weights (remain equalised (RE), n=9 litters). The 7-day-old piglets from 2STEP7 were transferred onto a sow 21 days into lactation (2STEP21, n=10 litters). The growth of new-born piglets on 1STEP21 and 2STEP7 nurse sows was initially lower than in RI litters (F 3,33.8=4.61; P<0.01), but weaning weights did not significantly differ (F 4,32.7=0.78; P>0.5). After the 1st week of lactation, the weights and growth rates did not differ between treatments. Fighting behaviour during nursing bouts decreased over time. The frequency of fights was higher in 1STEP21 and 2STEP21 litters compared with RI litters (t 122=3.06 and t 123=3.00, respectively, P<0.05). The 2STEP21 litters had shorter nursing bouts than RI and 1STEP21 litters (t 107=-2.81 and t 81.7=2.8, respectively, P<0.05), which were more frequently terminated by 2STEP21 than RI sows (t 595=2.93; P<0.05). Transferring heaviest piglets from RI and RE litters to nurse sows reduced the percentage of teat changes during nursing bouts (RI: F 1,275=16.61; RE: F 1,308=43.59; P<0.001). In conclusion, nurse sow strategies do not appear to compromise piglet growth. However, new-born piglets transferred onto sows in late lactation experienced more competition at the udder, suggesting that the sows' stage of lactation is of importance to how achievable nurse sow strategies are. Thus, the two-step nurse sow strategy is likely the best option (in relation to growth and suckling behaviour), as it minimises the difference between piglet age and sow stage of lactation.

Alfalfa hay improves nursing performance of Awassi ewes and performance of growing lambs when used as a source of forage compared with wheat straw.

Two experiments were conducted to evaluate the effect of replacing wheat straw (WS) with alfalfa hay (ALF) in diets fed to Awassi lactating ewes (exp. 1) and weaned lambs (exp. 2). In each experiment, sheep were fed 1 of 3 treatment diets containing WS only, WS and ALF mix (50:50; WS-ALF), or ALF only as the forage sources. In exp. 1, 33 lactating Awassi ewes were assigned randomly to treatment diets (11 ewes/diet) and fed ad libitum for 56 days. Intakes of dry matter (DM) and crude protein (CP) were greater (P = 0.001) in WS-ALF and ALF diets than WS diet. Ewe weight-of-lamb weaned, and nursing-lamb average daily gain (ADG) was greatest for ALF, intermediate for WS-ALF, and least for WS treatment groups (P < 0.0001). Milk production (kg/day) tended to be greater (P = 0.07) in ALF diets compared with WS diets. Milk protein, total solids, and lactose production (g/day) were greater (P < 0.04) in ewes fed ALF and WS-ALF diets compared with WS diet. In exp. 2, 27 newly weaned lambs were randomly assigned to treatment diets (9 lambs/treatment) and fed ad libitum for 70 days. Intake and digestibility of DM were greater (P < 0.05) in lambs fed the ALF diet compared with the WS diet. Lamb total gain and ADG were greater (P < 0.01) for lambs fed WS-ALF and ALF diets compared with WS diet. Replacement of wheat straw with alfalfa hay improved most of performance and productivity measured variables of Awassi lactating ewes and growing lambs.

Associations between group sizes, serum protein levels, calf morbidity and growth in dairy-beef calves in a Finnish calf rearing unit.

Efficient dairy-beef production relies on good quality of purchased calves, defined by breed, health, and growth characteristics. Several management factors, such as commingling of calves and large group size, predispose calves to diseases. Acute phase proteins are sensitive detectors of calf diseases. We studied the associations between group size, serum acute phase proteins, immunoglobulin G (IgG), calf morbidity and growth of dairy-beef calves in a random field trial in a calf-rearing unit in Finland. The randomized trial was carried out at a calf rearing unit, where approximately 80 dairy or crossbred calves were allocated either into a single group of 40 calves or into four groups of 10 on arrival at the calf-rearing unit (at age 24.1 SD ± 9.2 days). The study was carried out on 6 arrival batches: 476 calves. Calves were clinically examined and blood sampled on arrival (day 0), and haptoglobin (Hp), serum amyloid A (SAA), albumin and IgG were determined. Calves were weighed on arrival (day 0, average age 24.1 days), at the end of the milk feed period (day 49), at approximately 200 days of age and at slaughter (carcass weight) at 15-18 months of age. During the rearing calves were observed by the farm workers and treated, if necessary, according to predetermined instructions of the veterinary surgeon. All NSAID and antimicrobial treatments were recorded and used as morbidity indicators in statistical analysis. There were no differences in the numbers of antimicrobial treatments or growth among the groups. The majority (84.1%) of antimicrobial treatments were used against respiratory tract infections. Higher concentrations of albumin and IgG on arrival extended the time before the first and the second antimicrobial treatments. Complex relationships between group size, morbidity, concentrations of serum acute phase proteins and IgG at arrival, and growth of calves were explored. Group size of 10 calves did not protect calves from respiratory tract infections, when the small groups were sharing the air space with a large group. An increased SAA concentration on arrival was associated with poorer average daily gain at two rearing periods and with lower carcass weight at slaughter. Serum proteins could be valuable health indicators for purchased calves because they have numerous and variable associations with health and growth. The mechanisms that connect increased SAA concentration and poorer average daily gain over the long term remain unclear.

Effects of butyrate supplementation in antibiotic-free milk replacer and starter on growth performance in suckling calves.

The aim of this study was to evaluate butyrate supplementation of antibiotic-free milk replacer and starter on growth performance in male Holstein calves. Twenty-nine calves were divided into two groups. Group C (n = 13) was fed antibiotic-free milk replacer without supplementation, and Group B (n = 16) was fed antibiotic-free milk replacer supplemented with butyrate (1.6 % DM of Gustor BP70® ). Starter in Group B contained 0.3 % DM of Gustor BP70® . The intake of milk replacer was lower in group B than in C (p = 0.07 for the treatment x week interaction). Body weight (BW) and heart girth (HG) in group B was higher than in C during the experimental period (p = 0.07 and 0.01 for the treatment × week interaction, respectively). The duration of the weaning period in group B was shorter than in group C (p = 0.02). ß-hydroxybutyrate (BHBA) was higher in group B than in C (p = 0.04). Insulin like growth factor-1 (IGF-1) concentrations tended to be higher in group B than in C (p = 0.07 for treatment × week interaction). Our results show that butyrate supplementation in antibiotic-free milk replacer and starter exerted positive effects on growth performance in suckling calves.

Preweaned heifer management on US dairy operations: Part I. Descriptive characteristics of preweaned heifer raising practices.

The objective of this study was to describe preweaned dairy heifer calf management practices on dairy operations across the United States that were used to analyze factors associated with colostrum quality and passive transfer, Cryptosporidium and Giardia, morbidity and mortality, and average daily gain. This study included 104 dairy operations in 13 states that participated in the National Animal Health Monitoring System's Dairy 2014 calf component study. This 18-mo longitudinal study focused on dairy heifer calves from birth to weaning, and data were collected on 2,545 heifer calves. Descriptive statistics were generated regarding colostrum feeding, preweaning housing, milk feeding and consumption, growth, morbidity and mortality, and weaning practices. The majority of calves enrolled were Holsteins (89.4%). Over half the calves (63.2%) enrolled in the study received the majority of their colostrum via bottle; however, 22.1% of calves from 51.0% of operations received colostrum via suckling from their dams. For all calves, the mean time to the first colostrum feeding was 2.8 h, and the average amount of colostrum at the first feeding was 2.9 L, with 4.5 L provided in the first 24 h. The mean serum IgG of all calves was 21.7 g/L; however, 76.0% of operations had at least 1 calf with failure of passive transfer of immunity with a serum IgG below 10 g/L. The majority of calves in the study were housed individually (86.6%). Nonetheless, 20.2% of operations housed some calves in groups, representing 13.4% of all calves. Approximately one-half of the calves in the study (52.3%) were dehorned or disbudded during the preweaning period, with only 27.8% of these calves receiving analgesics or anesthetics during the procedure. Whole or waste milk was the liquid diet type fed to 40.1% of calves, and milk replacer was fed to 34.8% of calves. A combination of milk and milk replacer was fed to 25.1% of calves. Calves, on average, were fed 2.6 L per feeding and fed 2.6 times/d, resulting in a total of 5.6 L of liquid diet fed per day. The mean average daily gain for all calves enrolled in the study was 0.7 kg/d. Fecal samples were collected and almost all operations had at least 1 calf positive for Cryptosporidium (94.2%) or Giardia (99.0%), and 84.6% of operations had calves that tested positive for both Cryptosporidium and Giardia. Over one-third of calves (38.1%) had at least one morbidity event during the preweaning period and the mortality rate was 5.0%. The mean age at weaning was 65.7 d. This study provides an update on dairy heifer raising practices in the United States.

Preweaned heifer management on US dairy operations: Part VI. Factors associated with average daily gain in preweaned dairy heifer calves.

The study objective was to evaluate average daily gain (ADG) in dairy heifer calves based on health, feeding, management practices, and environmental factors. This study included 102 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,410 Holstein heifer calves monitored from birth to weaning. The mean ADG from birth to final weight was 0.74 kg/d. Backward elimination model selection in Proc Mixed after univariate screening determined factors that significantly affected ADG. The final model included dam lactation number, singleton versus twin birth, bedding type, Giardia and Cryptosporidium fecal shedding, disease events, a categorized average temperature-humidity index for the preweaning period (pTHI), amount of protein in the liquid diet (kg/d), milk pasteurization, direct-fed microbials, and the interaction between milk pasteurization and direct-fed microbials. After controlling for other independent variables in the model, calves born to first-lactation dams gained less (0.60 kg/d) than calves from second- (0.65 kg/d) or third- or greater-lactation (0.64 kg/d) dams. Singleton calves gained 0.07 kg/d more than twins. Calves bedded with sand or no bedding gained less (0.49 kg/d) than calves on all other bedding types. Calves negative for Cryptosporidium or Giardia at the time of sampling gained 0.03 or 0.02 kg/d more, respectively, than calves that were positive for Cryptosporidium or Giardia. Calves with no disease events gained 0.07 kg/d more than calves with one or more disease events. Calves experiencing an average pTHI <50 gained more (0.67 kg/d) than calves experiencing an average pTHI from 50 to 69 (0.62 kg/d), or ≥70 (0.59 kg/d). Within the range of observed kilograms of protein fed per day in the liquid diet, every additional 0.1 kg of protein fed per day equated to 0.02 kg/d of gain. Calves fed milk replacer with a direct-fed microbial gained less (0.44 kg/d) than calves fed milk replacer without a direct-fed microbial (0.60 kg/d) and calves fed pasteurized or unpasteurized milk regardless of direct-fed microbial use. These results highlight the importance of feeding a quantity and quality of a liquid diet to achieve optimal growth, keeping calves free of disease, the type or status of bedding, and mitigating the effects of temperature and humidity on preweaning ADG.