Effects of amount of milk, milk flow and access to a rubber teat on cross-sucking and non-nutritive sucking in dairy calves

The aim of this study was to test the effects of different amounts of milk, flow rate of milk, and access to a teat after milk intake on non-nutritive sucking on an empty teat and on cross-sucking on other calves in Bos taurus dairy calves. An additional aim was to test if calves prefer to perform non-nutritive sucking on a teat with the taste of milk or on a clean teat. First experiment involved 11 groups of three calves during gradual decrease from 5 to 2.5 and 1 to 0l of whole milk per meal twice daily. Milk flow was either 0.5 or 1l/min, and the teat buckets were either left or removed after milk intake. When the calves were fed with 5l of milk, non-nutritive sucking and cross-sucking decreased (P<0.001), compared to 1 and 2.5l. Removing the empty teat after milk intake increased cross-sucking (P<0.001). Slow milk flow reduced non-nutritive sucking after milk intake (P<0.05), but did not influence cross-sucking. Duration of recorded milk intake was similar with fast flow and 5l of milk, compared to slow flow and 2.5l of milk. The latter combination increased non-nutritive sucking and cross-sucking, suggesting that amount of milk is more important than duration of milk intake.Second experiment was carried out on 12 individually kept calves. The calves received 2.5l of milk either in an open bucket, in a rubber teat bucket, or half/half in both buckets. When not used for feeding, the open bucket and the teat bucket were filled and emptied again to make them 'tasty' with some drops of milk. The tasty teat bucket was either removed or present after milk intake. The calves had always access to a second clean teat bucket. Source of milk had no influence on recorded behaviour after milk intake. The tasty teat was sucked for twice as long as the clean one when both teats were present (P<0.001). When the tasty teat was removed, the calves increased sucking on the clean teat (P<0.001), but decreased total time spent sucking (P<0.001). We conclude that a high amount of milk and the presence of the teat bucket after milk intake reduces cross-sucking, and that a clean teat is less effective in encouraging calves to suck than a teat with taste of milk.     

Sucking behaviour of dairy calves fed milk ad libitum by bucket or teat

The milk intake and sucking behaviour of Dutch and Holstein-Friesian crossbred calves fed milk replacer ad libitum by either the bucket method (n=8) or an artificial teat (n=6) were compared. The animals were observed for 3 weeks from the age of 2 weeks, penned individually and all provided with a “dummy” (artificial) teat near the milk source within the pen.

The teat-fed calves ingested significantly more milk than the bucket-fed calves (11.9 vs. 8.0 kg/day; P<0.05), and this intake took much longer (44.2 vs. 17.7 min/day; P<0.05). In both treatment groups, milk intake was organized in “meals”. The meal criterion, separating the withinmeal and between-meal non-feeding intervals, was set at 5 min. Frequency of meals and daily total meal duration did not differ significantly. Meals occurred rather randomly throughout a 24-h period.

On average, the dummy teat was used for 13 min per day by bucket-fed calves, but for only 1 min by teat-fed calves (P<0.05). Sucking of the dummy teat was largely clustered within the meal periods.

It is concluded that in the young calf a need for sucking exists independently of milk satiation. However, the level of satiation depends on whether the calf drinks or sucks the milk. Nutritive sucking is clearly more reinforcing than non-nutritive sucking.     

The use of social information about predation risk by foraging house sparrows: a feeder experiment

Journal of Ethology - There is increasing evidence of social information transfer about predation risk in foraging animal groups. However, little is known about whether individuals also acquire...     

A simple electrically-operated feeder for use in salmon rearing

The construction of a simple, automatic feeder designed to dispense dry food used in salmon rearing is described. The feeder is powered by a 12 V battery and controlled by two electric clocks. Frequency of feeding, the daily duration of the feeding period, and the quantity of food dispensed can be adjusted.     

Reduction in laboratory animal use by factorial design

Factorial experimental designs (FEDs) can be used to study the effects of controllable variables, such as an experimental treatment, sex, strain, age, diet and prior treatment of animals, on some defined response. Such designs have been widely used in optimising manufacturing processes, but have rarely been used in optimising animal experiments in drug discovery. FEDs generally provide more information than the alternative "one-variable-at-a-time" approach, because each animal contributes information on the effect of every factor, and because such designs can highlight any interactions among the variables. Although FEDs can have any number of factors and levels of each factor, where many factors are to be explored, it is common to do an initial experiment using two levels of each factor, and in some cases fractional factorial designs can be used to reduce the total number of treatment combinations to manageable levels. These designs have been used successfully at AstraZeneca in the optimisation of in vivo drug screening experiments, where their use has effectively reduced the numbers of animals used in some routine screens.     

The effect of age at introduction and number of milk-portions on the behaviour of group housed dairy calves fed by a computer controlled milk feeder

This study is an investigation of the effect of age at introduction (6 days versus 14 days) and number of milk-portions (four milk-portions a day versus eight milk-portions a day) on integration into a large dynamic group of calves, fed by a computer controlled milk feeder. Forty calves (Jerseys, Danish Reds and Holstein-Friesians) were allocated equally to the two age conditions (A6 and A14) and the two milk-portion conditions (M4 and M8) in a 2 × 2 factorial design, according to sex and breed, and introduced into the group in pairs (one A6 and one A14). The behaviour of each pair was video-recorded for 8 h from 8 a.m. to 4 p.m. and 1 h from 1 to 2 a.m. on days 1, 8 and 15 after introduction.

The A6 calves performed less licking and sniffing, changed posture more often and tended to spend less time standing than the A14 calves. In the course of time A14 calves lay closer to other calves than the A6 calves.

The M8 calves, which were offered the same daily milk allowance as the M4 calves stood for a longer time in the milk feeding station and the M8 calves also sucked the empty teat more frequently than the M4 calves. Finally, the M8 calves initiated more social play behaviour than the M4 calves. On the first day after introduction the M8 calves lay closer to other calves than the M4 calves.

The results suggest that calves integrate better into a group when introduced at the age of 14 days than at the age of 6 days. Distributing the milk into eight daily milk-portions, rather than four milk-portions in the first period after introduction, increased milk feeder occupancy, which may facilitate learning to use the milk feeder. Surprisingly, more milk-portions also stimulated play behaviour, which is suggested to be due to M8 calves encountering more calves in the milk feeder area.     

Individual variation and seasonality drive bird feeder use during winter in a Mediterranean climate

Purposeful provisioning of food to wild animals is a widespread and growing activity that has the potential to impact populations and communities. Nevertheless, studies assessing use of recreational feeders by free‐living birds during winter are surprisingly rare and largely limited to regions with continental climates characterized by freezing temperatures and snow cover. In contrast, there is little information available regarding bird use of feeders within warmer climates during winter, despite widespread recreational feeding in these areas. In this study, we quantified visitation patterns to bird feeders in a Mediterranean climate to evaluate the relationship between feeder use and several environmental variables known to influence supplemental feeder use in continental climates. We established a network of bird feeders in Corvallis, Oregon, USA, that were filled with black oil sunflower (Helianthus annuus) seeds and equipped with radio frequency identification (RFID) data loggers that recorded >315,000 visits by 70 individual Black‐capped Chickadees (Poecile atricapillus) across a 5‐month period (October 2016–March 2017). We found extensive variation in feeder use, with individuals averaging 1–406 feeder visits/day and using 1–9 of the 21 feeders that were available; individual variability was largely consistent during the course of our study. At the population level, we found that feeder use decreased from the start of our study, and this decline continued through the period when foraging was most limited by daylight, including the winter solstice. In contrast to theoretical predictions and empirical work in continental climates, we found that weather variables did not drive feeder use and that feeder visits peaked at mid‐day and gradually decreased until sunset. Our study indicates that individual‐level differences combined with seasonality to drive feeder use patterns, and we conclude that use of supplemental feeders during winter in Mediterranean climates appears to differ notably from feeder use in continental climates.     

Reduction of radiocaesium transfer to broiler chicken meat by a clinoptilolite modified with hexacyanoferrate

The effect of RADEKONT (a natural clinoptilolite modified by hexacyanoferrate) on ¹³⁷Cs uptake into meat was tested in experiments with broiler chickens. Three experiments determined the influence of RADEKONT on radiocaesium transfer after single or repeated applications of artificially contaminated feed mixture and one experiment investigated the effect of RADEKONT when feeding a mixture containing wheat contaminated by the Chernobyl fallout. Independent of the effect of RADEKONT, the uptake of radiocaesium was faster in leg meat than in breast meat. Reduction factors (¹³⁷Cs transfer without the RADEKONT additive compared with those observed after supplementation of the additive into the feed mixture) of 1.1–1.3 and 1.2–2.3, respectively, were achieved after single and repeated administrations of artificially contaminated feed. No significant differences in reduction between breast and leg meat were observed. RADEKONT was more effective when the chickens were fed with Chernobyl-contaminated wheat (reduction factors of up to 3.7) than an artificial ¹³⁷Cs source. RADEKONT as a supplement during the decontamination period decreased the biological half-life of ¹³⁷Cs to less than 1 day. The timing of the application of RADEKONT might be important in determining its effectiveness, especially in young, rapidly growing chickens. Received: 9 January 1998 / Accepted in revised form: 10 January 1999     

Reduction of cryoprotectant toxicity in cells in suspension by use of a sodium-free vehicle solution

Propane-1,2-diol (PD) possesses physico-chemical properties that make it a useful biological vitrifying agent but, although of relatively low toxicity, it still has substantial damaging effects on cells. This study aimed to identify possible toxic mechanisms using primary cell cultures from vascular tissue: these were exposed to the cryoprotectant at room temperature to avoid any possibility of hypothermic injury. Toxicity was evaluated by measuring the ability of the cells to divide in culture after exposure to the cryoprotectant. A variety of interventions, which addressed either possible consequences of PD exposure, or known mediators of other types of cell injury, were utilized in an attempt to inhibit PD toxicity. Some comparative studies with dimethyl sulphoxide (Me₂SO) exposure were also made.Replacing sodium in the vehicle solution with choline was the only intervention that reduced PD toxicity. It did so both in smooth muscle cells, where the loss of functional capacity was reduced from 56% to 13%, and in endothelial cells. where the reduction was from 40% to18%. Similar observations were also made in smooth muscle cells exposed to Me₂SO. We failed to find evidence for a role of pH regulation, for oxidative injury and/or an involvement of redox-active iron as a mediator of the injury. The results strongly suggest that the influx of sodium into the cell provides one mechanism whereby both PD and Me₂SO exert their toxic effects. We suggest that the use of choline-based vehicle solutions in cryopreservation would be beneficial.     

Genotyping by sequencing reveals a new locus for pig teat number

Teat number is an extremely valuable trait for sow reproduction performance and piglet survival. Here, we used genotyping‐by‐sequencing and a general liner model to carry out genome‐wide analysis of sow total teat number in an Erhualian population. The results indicated that eight SNPs on chromosomes 4, 5, 9 and 10 were significant genome wide (Bonferroni method, P < 2.85E‐7) for sow total teat number. Validation analyses were performed in 298 Erhualian and 904 Large White sows using these significant SNPs and the general liner model procedure in sas . Finally, only the SNP on chromosome 5 was found to be significantly associated with sow teat number in both populations. The GG genotype individuals had 2.23 and 0.82 more teat numbers respectively than did the AA genotype individuals in these two populations (P < 0.05). According to the expression and annotation analyses, we inferred the presence of a gene or lincRNA that could affect teat number by regulating other genes and ultimately affecting the mammogenesis of pigs. Further studies using methods such as Cas9 editing and gene silencing analysis are necessary for additional function analysis.     

Plasma biomarker profiling in the detection of growth promoter use in calves

The detection of illicit growth promoter use during meat production within the European Union is reliant on residue testing which is a limiting factor on the number of animals which can be tested and consequently compromises the efficacy of testing procedures. The present study examined a novel detection strategy based on the profiling of plasma component concentrations in response to growth promoter administrations. Calves subjected to nortestosterone decanoate, 17β-oestradiol benzoate and dexamethasone were found to have altered urea, aminoterminal propeptide of type III procollagen and sex hormone binding globulin profiles in response to treatments. These findings demonstrate the potential of using the identification of perturbed profiles within a panel of biomarkers which cover a spectrum of biological activity to reveal growth promoter abuse.     

Plasma biomarker profiling in the detection of growth promoter use in calves

The detection of illicit growth promoter use during meat production within the European Union is reliant on residue testing which is a limiting factor on the number of animals which can be tested and consequently compromises the efficacy of testing procedures. The present study examined a novel detection strategy based on the profiling of plasma component concentrations in response to growth promoter administrations. Calves subjected to nortestosterone decanoate, 17β-oestradiol benzoate and dexamethasone were found to have altered urea, aminoterminal propeptide of type III procollagen and sex hormone binding globulin profiles in response to treatments. These findings demonstrate the potential of using the identification of perturbed profiles within a panel of biomarkers which cover a spectrum of biological activity to reveal growth promoter abuse.     

Growth and teat ownership in a litter of binturongs

Teat ownership has been hypothesized to reduce competition among littermates and has been documented in several species. This study was conducted at the Conservation and Research Center to determine if competition and ownership occurred in the binturong (Arctictis binturong). One litter of four cubs was observed for 2 h, three times per day for 16 wk. Cubs showed definite teat preferences, but no exclusive ownership. Competition, as measured by teat fighting, occurred most frequently for the inguinal pair of mammae. The cubs that suckled most frequently on the inguinal teats had a faster growth rate after day 45. Thus, based on suckle frequency, fight frequency, and growth rates, binturong cubs prefer the inguinal pair of teats.     

Characterization of bifidobacteria suitable for probiotic use in calves

In our previous experiment, the ten calves originated bifidobacterial strains were administered to calves and re-isolated. Fingerprinting techniques used in this study enabled us to distinguish the surviving and non-surviving strains. Only the species Bifidobacterium animalis ssp. animalis and Bifidobacterium longum ssp. suis were found to survive in the intestine.     

Reduction of gene repair by selenomethionine with the use of single-stranded oligonucleotides

Background  

The repair of single base mutations in mammalian genes can be directed by single-stranded oligonucleotides in a process known as targeted gene repair. The mechanism of this reaction is currently being elucidated but likely involves a pairing step in which the oligonucleotide align in homologous register with its target sequence and a correction step in which the mutant base is replaced by endogenous repair pathways. This process is regulated by the activity of various factors and proteins that either elevate or depress the frequency at which gene repair takes place.     

Spatial and temporal variability of aquatic habitat use by amphibians in a hydrologically modified landscape

1. Habitat loss is a major driver of biodiversity decline worldwide. Temporary waterbodies are especially vulnerable because they are sensitive both to human impact and to climatic variations. Pond‐breeding amphibians are often dependent on temporary waterbodies for their reproduction, and hence are sensitive to loss of temporary ponds. 2. Here we present the results of a 5‐year study regarding the use of temporary aquatic habitats by amphibians in a hydrologically modified area of Eastern Europe (Romania). The annual number of aquatic habitats varied between 30 and ～120. Each aquatic habitat was characterised by a number of variables such as: ‘type’ (pond, drainage ditch and archaeological ditch), ‘hydroperiod’ (number of weeks the ponds were filled in a given year), ‘depth’ (cm), ‘area’ (m²) and the density of predatory insects (‘predation’). The turnover rate for each amphibian species for each wetland was calculated based on the pond occupancy. 3. Eight amphibian species were recorded from the aquatic habitats. Hydroperiod was the most important variable, positively influencing wetland use by amphibians and their reproductive success. Most species preferred drainage ditches for reproduction, and the reproductive success was highest in this habitat type every year. For most of the species, the local extinction rate was higher than the colonisation rate in the first 4 years, but the situation reversed in the last year of the study when wetland use by amphibians sharply increased because of high rainfall. 4. This study confirms the importance for amphibians of maintaining and managing aquatic habitat diversity at small spatial scales. Man‐made aquatic habitats such as drainage ditches may be important habitats for amphibians, and this should be considered in restoration activities.     

Reduction of technetium by Desulfovibrio desulfuricans: biocatalyst characterization and use in a flowthrough bioreactor.

Resting cells of Desulfovibrio desulfuricans coupled the oxidation of a range of electron donors to Tc(VII) reduction. The reduced technetium was precipitated as an insoluble low-valence oxide. The optimum electron donor for the biotransformation was hydrogen, although rapid rates of reduction were also supported when formate or pyruvate was supplied to the cells. Technetium reduction was less efficient when the growth substrates lactate and ethanol were supplied as electron donors, while glycerol, succinate, acetate, and methanol supported negligible reduction. Enzyme activity was stable for several weeks and was insensitive to oxygen. Transmission electron microscopy showed that the radionuclide was precipitated at the periphery of the cell. Cells poisoned with Cu(II), which is selective for periplasmic but not cytoplasmic hydrogenases, were unable to reduce Tc(VII), a result consistent with the involvement of a periplasmic hydrogenase in Tc(VII) reduction. Resting cells, immobilized in a flowthrough membrane bioreactor and supplied with Tc(VII)-supplemented solution, accumulated substantial quantities of the radionuclide when formate was supplied as the electron donor, indicating the potential of this organism as a biocatalyst to treat Tc-contaminated wastewaters.