Effect of crate opening from day 3 postpartum to weaning on nursing and suckling behaviour in domestic pigs.

Temporary crating may be a more acceptable housing system for lactating sows than permanent crating and loose-housing because it combines benefits of both systems while reducing some of their limitations. It remains unclear whether nursing and sucking behaviour is influenced after crate opening. The aim of this study was to assess the short- (24 h post-crate opening) and long-term (day 25 postpartum (pp.)) effects of opening the farrowing crate from day 3 pp. to weaning on nursing and suckling behaviour. Sows were crated from 5 days prepartum either to weaning (permanently crated group; n = 14) or 3 days pp. (temporarily crated group; n = 13). Sows and their litters were observed on days 4 and 25. Duration of pre- and post-massages, nursing termination, number of piglets missing milk ejection and number of piglets fighting during pre- and post-massages were scored at 15-s intervals. Nursing success (i.e. with or without milk ejection) was also recorded. Data were analysed using PROC GLM and PROC GENMOD of SAS including housing, litter size and parity as fixed effects. Nursing behaviour did not differ between sows housed in temporary crates and those housed in permanent crates on days 4 and 25 pp., that is, same number of nutritive nursings (NNs), same proportion of non-NNs, same duration of post-massages and same proportion of termination of post-massages. There was only a housing effect on day 25; with sows having longer pre-massages in permanent crates (P < 0.05). Suckling behaviour was overall similar between treatments. There were no differences in the number of piglets attending pre- and post-massages, proportion of piglets fighting during pre-and post-massages and the proportion of piglets missing milk ejection on both days. The only housing effect was found on day 25 during which fewer piglets attended post-massages (P < 0.05) in permanent crates. Sows with larger litters terminated post-massages more often (P < 0.05), allowed shorter post-massages (P < 0.05) on day 4, and had more piglets miss milk ejection on days 4 and 25 (P < 0.05). In conclusion, the results of this study showed that housing had a very limited effect on nursing and suckling behaviour. Sow and piglet behaviours were not altered after crate opening (short-term effect) and nursing was to some extent calmer (shorter pre-massages and more piglets attended post-massages) in temporary crates on day 25. Increased litter size impaired nursing and suckling behaviour of sows and piglets independently of the housing system.

Comparison of shortened and conventional dry period management strategies.

The aim of this study was to compare 2 dry-cow management strategies and evaluate the effect of shortened dry period strategy on feed intake, metabolism, and postpartum performance of dairy cows in early lactation. Twenty-nine high-yielding dairy cows were divided into 2 groups. The control (CON) group (n=14) was assigned to a traditional dry period of approximately 60 d (57±5.9 d) and was fed a far-off dry cow ration from dry-off to -21 d relative to expected parturition. From d -21 relative to expected parturition, the cows were switched to a precalving ration containing an additional 3kg of concentrates. The cows of the experimental group (n=15) were assigned to a shortened dry period (SDP; 35±6.3 d) and were continuously fed a late-lactation diet from d -60 d relative to expected parturition until calving. After calving, both groups were fed the same lactation diet corresponding to their lactation requirements and cows were followed for 100 d of lactation. Prepartum dry matter intake of the cows assigned to an SDP and fed a late-lactation diet was approximately 4.11kg/cow per day greater compared with the CON group during the 60 d. However, no effect of dry period strategy on postpartum dry matter intake was detected. The cows with an SDP produced approximately 2.78kg/d (6.9%) less milk in the first 100 d of lactation than CON cows; the difference was not statistically significant. No differences were observed in live body weight, body condition score, or back-fat thickness between the treatments. Similarly, no differences existed in concentrations of plasma metabolites. The cows of the SDP group showed lower pH and increased concentrations of lactic acid and volatile fatty acids prepartum than the CON cows. Postpartum concentrations of lactic acid, volatile fatty acids, and NH3 and pH in rumen fluid did not differ between the treatments. Shortening of the dry period did not affect the colostrum quality or birth weights of the calves. Based on the results of this study, a traditional dry period management strategy appeared to be more favorable, considering the dry matter intake and milk production, compared with an SDP and feeding a late-lactation diet throughout the dry period.

Contribution of domestic production records, Interbull estimated breeding values, and single nucleotide polymorphism genetic markers to the single-step genomic evaluation of milk production.

Estimated breeding values (EBV) for first-lactation milk production of Holstein cattle in the Czech Republic were calculated using a conventional animal model and by single-step prediction of the genomic enhanced breeding value. Two overlapping data sets of milk production data were evaluated: (1) calving years 1991 to 2006, with 861,429 lactations and 1,918,901 animals in the pedigree and (2) calving years 1991 to 2010, with 1,097,319 lactations and 1,906,576 animals in the pedigree. Global Interbull (Uppsala, Sweden) deregressed proofs of 114,189 bulls were used in the analyses. Reliabilities of Interbull values were equivalent to an average of 8.53 effective records, which were used in a weighted analysis. A total of 1,341 bulls were genotyped using the Illumina BovineSNP50 BeadChip V2 (Illumina Inc., San Diego, CA). Among the genotyped bulls were 332 young bulls with no daughters in the first data set but more than 50 daughters (88.41, on average) with performance records in the second data set. For young bulls, correlations of EBV and genomic enhanced breeding value before and after progeny testing, corresponding average expected reliabilities, and effective daughter contributions (EDC) were calculated. The reliability of prediction pedigree EBV of young bulls was 0.41, corresponding to EDC=10.6. Including Interbull deregressed proofs improved the reliability of prediction by EDC=13.4 and including genotyping improved prediction reliability by EDC=6.2. Total average expected reliability of prediction reached 0.67, corresponding to EDC=30.2. The combination of domestic and Interbull sources for both genotyped and nongenotyped animals is valuable for improving the accuracy of genetic prediction in small populations of dairy cattle.

The effect of nesting material on the nest-building and maternal behavior of domestic sows and piglet production.

Nest building is an important part of maternal behavior in domestic pigs. The aim of the study was to assess the effect of nesting material sawdust vs. straw on sow behavior 24 h before and after birth of the first piglet (BFP) and piglet production. Sows, housed in farrowing crates, were randomly divided into 2 treatments: sawdust (n = 12) and straw (n = 13). Sawdust and straw were provided during the pre- and parturient period; after parturition, straw was given to both experimental groups. The prepartum nesting period (the time interval between the first and last nest-building records, including all other activity and resting before BFP), the nesting records (number of nesting records), nesting duration (duration of all nesting records), the start and termination of nesting, and the frequency of prepartum postural changes were collected 24 h before BFP. After BFP, number of nesting records and time to first sucking of the litter were collected. Frequency of postural changes and duration of udder access were collected 24 h after BFP during 3 time periods (during parturition, from the end of parturition to 12 h after BFP, and 12 to 24 h after BFP) and the frequency of nursing during 2 time periods (from the end of parturition to 12 h after BFP, and 12 to 24 h after BFP). Piglet BW gain and mortality were estimated 24 h after BFP. Data were analyzed using PROC MIXED and the probability of the piglet mortality using PROC GENMOD in SAS. Nesting material did not affect (P > 0.10) most of sow prepartum nesting behavior and had no effect (P > 0.10) on the prepartum frequency of postural changes. Sows from the sawdust treatment had a longer nesting period (P < 0.05), and nest building tended to start sooner (P < 0.10) than in the straw treatment. Nesting material had only a small effect on later maternal behavior. Sows from the straw treatment tended to have more nesting records after BFP (P < 0.10). The frequency of postural changes was affected by the interaction (P < 0.01) between treatments and time period: sow from the straw treatment had more postural changes during parturition compared with other time periods and sawdust treatment. No effect (P > 0.10) of the nesting material on piglet BW gain and mortality was found. The results suggest that sawdust compared with straw as nesting material provided to sows before and through parturition does not negatively affect maternal behavior during the 24 h before and after parturition or piglet production. Therefore, sawdust can be recommended as a suitable nesting material for farrowing sows when straw is not available.

Role of beta adrenoceptors in metabolic and cardiovascular responses of cold exposed humans.

Effect of a nonspecific beta adrenergic blocker - propranolol (40 mg per os) on thermoregulatory responses of cold water immersed (12.5 degrees C) humans was studied. Propranolol attenuates resting and cold induced thermogenesis, rectal temperature, heart rate and systolic blood pressure, but increases production of adrenaline and cortisol. Propranolol has no effect on the threshold body temperature for induction of cold thermogenesis and on central thermosensitivity. The following conclusions are drawn from consideration of the data presented: During the early phase of cooling (20 min after the start of cooling) the thermogenesis mediated by beta adrenergic receptors may cover about 80% of the total metabolic increase induced by cold. After about 30 min of cooling the relative proportion of beta adrenergic thermogenesis starts to decline, reaching 20% of the total cold thermogenesis at the end of cooling.It can be suggested from consideration of the data that, in man, the beta adrenergic receptors in the heart, blood vessels, adipocytes and muscles participate in mediating effect of cold on cardiovascular and thermoregulatory responses. Furthermore, these data imply that human adrenergic thermogenesis is produced outside of the brown adipose tissue. Thus, physiological mechanisms mediating adrenergic thermogenesis in humans appear to be different from those in small mammals.

Human physiological responses to immersion into water of different temperatures.

To differentiate between the effect of cold and hydrostatic pressure on hormone and cardiovascular functions of man, a group of young men was examined during 1-h head-out immersions in water of different temperatures (32 degrees C, 20 degrees C and 14 degrees C). Immersion in water at 32 degrees C did not change rectal temperature and metabolic rate, but lowered heart rate (by 15%) and systolic and diastolic blood pressures (by 11 %, or 12%, respectively), compared to controls at ambient air temperature. Plasma renin activity, plasma cortisol and aldosterone concentrations were also lowered (by 46%, 34%, and 17%, respectively), while diuresis was increased by 107%. Immersion at 20 degrees C induced a similar decrease in plasma renin activity, heart rate and systolic and diastolic blood pressures as immersion at thermoneutrality, in spite of lowered rectal temperature and an increased metabolic rate by 93%. Plasma cortisol concentrations tended to decrease, while plasma aldosterone concentration was unchanged. Diuresis was increased by 89%. No significant differences in changes in diuresis, plasma renin activity and aldosterone concentration compared to subjects immersed to 32 degrees C were observed. Cold water immersion (14 degrees C) lowered rectal temperature and increased metabolic rate (by 350%), heart rate and systolic and diastolic blood pressure (by 5%, 7%, and 8%, respectively). Plasma noradrenaline and dopamine concentrations were increased by 530% and by 250% respectively, while diuresis increased by 163% (more than at 32 degrees C). Plasma aldosterone concentrations increased by 23%. Plasma renin activity was reduced as during immersion in water at the highest temperature. Cortisol concentrations tended to decrease. Plasma adrenaline concentrations remained unchanged. Changes in plasma renin activity were not related to changes in aldosterone concentrations. Immersion in water of different temperatures did not increase blood concentrations of cortisol. There was no correlation between changes in rectal temperature and changes in hormone production. Our data supported the hypothesis that physiological changes induced by water immersion are mediated by humoral control mechanisms, while responses induced by cold are mainly due to increased activity of the sympathetic nervous system.