Consumption of Solid Food by Suckling Pigs: Individual Variation and Relation to Weight Gain

Individual daily consumption of supplementary solid food (\u27creep feed\u27) was measured from Day 10 to weaning at Day 28 for 39 piglets in four litters, and its relationship to body weight and weight gain up to Day 42 was investigated. Individual consumption was measured by combining the weight of the feed removed from the dispensers (monitored electronically) and a video image of piglet activity at the feeder. Creep feed consumption varied greatly, both between and within litters. On average, pigs began feeding on Day 12 (range Day 10-28), intake was relatively low (usually \u3c 5 g day ‒1) until Day 20 but increased considerably in the week before weaning, with a mean intake of 63 g day ‒1 (range 2-205 g day ‒1) during that week. Over the entire creep-feeding period, total feed consumption ranged from 13-1911 g per pig. Within litters, intake was positively correlated with birth weight (P \u3c 0.05) and the correlation with weight gains to Day 20 tended to be positive rather than negative. This suggests that greater creep feed intake was typical of the larger and more mature piglets, rather than serving as compensation for poor milk intake among the more deprived litter-mates. However, one exceptional pig began, on Day 14 after several days of weight loss, to eat more creep feed than any other piglet studied, suggesting that compensatory creep feeding can occur at a young age in exceptional cases. In a multiple regression analysis, creep feed intake accounted for 37% of the variation in weight gain in the week before weaning (P \u3c 0.001) and 7% of the variation in gain from Day 10 to weaning (P \u3c 0.01) after variation attributable to antecedent variables had been taken into account. Within-litter differences in weight gain during the 2 weeks after weaning were correlated with weight at birth and weight gain before weaning (P \u3c 0.05), but not with pre-weaning creep feed intake. Hence, creep feed intake appeared to contribute to pre-weaning gains and these in turn were correlated with post-weaning gains; however, a more direct effect of pre-weaning creep feed intake on post-weaning gain could not be detected

Mixing at Young Ages Reduces Fighting in Unacquainted Domestic Pigs

Under normal farming practices, piglets from different litters are often mixed around the time of weaning, and a high incidence of fighting and minor injuries often occur. The aim of this experiment was to determine the effect of age on the incidence of fighting in piglets mixed before weaning, at different ages between 5 and 26 days. We found no significant relationship between age and the likelihood that a pair of piglets would fight during the first 75 min after mixing. However, the duration of the first fight observed increased from 101±38 s at 5 days to 621±278 s at 26 days, mainly because of higher levels of unretaliated harassment and resting during the bouts. Younger pigs also showed 80% fewer injuries from the fighting. The results suggest some potential welfare advantage to allowing litters to mix at younger ages

Winning the Genetic Lottery: Biasing Birth Sex Ratio Results in More Grandchildren.

Population dynamics predicts that on average parents should invest equally in male and female offspring; similarly, the physiology of mammalian sex determination is supposedly stochastic, producing equal numbers of sons and daughters. However, a high quality parent can maximize fitness by biasing their birth sex ratio (SR) to the sex with the greatest potential to disproportionately outperform peers. All SR manipulation theories share a fundamental prediction: grandparents who bias birth SR should produce more grandoffspring via the favored sex. The celebrated examples of biased birth SRs in nature consistent with SR manipulation theories provide compelling circumstantial evidence. However, this prediction has never been directly tested in mammals, primarily because the complete three-generation pedigrees needed to test whether individual favored offspring produce more grandoffspring for the biasing grandparent are essentially impossible to obtain in nature. Three-generation pedigrees were constructed using 90 years of captive breeding records from 198 mammalian species. Male and female grandparents consistently biased their birth SR toward the sex that maximized second-generation success. The most strongly male-biased granddams and grandsires produced respectively 29% and 25% more grandoffspring than non-skewing conspecifics. The sons of the most male-biasing granddams were 2.7 times as fecund as those of granddams with a 50:50 bias (similar results are seen in grandsires). Daughters of the strongest female-biasing granddams were 1.2 times as fecund as those of non-biasing females (this effect is not seen in grandsires). To our knowledge, these results are the first formal test of the hypothesis that birth SR manipulation is adaptive in mammals in terms of grandchildren produced, showing that SR manipulation can explain biased birth SR in general across mammalian species. These findings also have practical implications: parental control of birth SR has the potential to accelerate genetic loss and risk of extinction within captive populations of endangered species

Effect of a single subcutaneous injection of meloxicam on chronic indicators of pain and inflammatory responses in 2-month-old knife and band-castrated beef calves housed on pasture

One hundred and thirty-one 2 mo. old pasture housed Angus cross bull calves were evaluated for 62 d over two years (Year 1: n = 69, 134.1 ± 20.37 kg BW; Year 2: n = 62, 118.1 ± 15.49 kg BW) to determine 1) the effects of a subcutaneous (s.c) injection of meloxicam on indicators of long term pain after castration and 2) the potential use of cow-calf proximity and home range as indicators of pain. Calves were randomly assigned to treatments using a 3 × 2 factorial design including castration - sham (CT; n = 47), band (BA; n = 46) or knife (KN; n = 38) castration and medication – s.c. meloxicam (M; n = 66) or s.c. lactated ringers solution (NM; n = 65). Measurements included performance, scrotal temperature, swelling (WS) and healing (WH) scores, and pain sensitivity, collected on d -1, 6, 13, 20, 34, 48, and 62 post-castration. Suckling, lying, standing and walking duration, and head-turning, lesion-licking, foot-stamping and tail-flick frequencies were collected immediately following and up to 2-d after castration. Cow-calf proximity and home range were obtained from d 0 to 2 and from d 14 to 16. With the exception of suckling, no medication (P > 0.05) effects were found. Greater (P < 0.05) pain sensitivity was observed in KN from d 6 to 34 and on d 62, and in BA from d 6 to 62 compared to CT calves. Knife calves showed an earlier (d 20) absence of inflammatory responses (WS; P < 0.05) than BA (d 34) and overall, KN calves had greater (P < 0.05) standing, walking, and head turning than BA and CT. Knife and BA had greater (P < 0.05) foot stamping than CT for the first 2 h post-castration, but KN exhibited greater (P < 0.05) frequencies between 9 and 11 h (d 0) compared to BA and CT, and had greater (P < 0.05) tail flicks from d 0 to 2 than CT. Banded calves were closer to their dams on d 15 while KN calves and their dams had a reduced home range on d 0 than CT cow-calf pairs. Although meloxicam did not reduce indicators of pain (with exception of suckling behavior), our results suggest that knife castration causes greater acute pain, while band castration resulted in greater chronic-pain. Cow-calf proximity and home range have some potential to be used as pain indicators post-castration.info:eu-repo/semantics/publishedVersio

Pharmacokinetics of oral and subcutaneous meloxicam: Effect on indicators of pain and inflammation after knife castration in weaned beef calves

Oral meloxicam is labelled for reducing pain and inflammation associated with castration in cattle in Canada, however, subcutaneous meloxicam is only labelled for pain associated with dis-budding and abdominal surgery. The aim of this project was to determine the pharmacokinetic profile of oral (PO; 1.0 mg/kg BW) and subcutaneous meloxicam (SC; 0.5 mg/kg BW), and to assess the effect of meloxicam on physiological and behavioural indicators of pain associated with knife castration in 7–8 month old calves. Twenty-three Angus crossbred beef calves (328 ± 4.4 kg BW) were randomly assigned to two treatments: PO n = 12 or SC n = 11 administration of meloxicam immediately before knife castration. Physiological parameters included salivary and hair cortisol, substance P, haptoglobin, serum amyloid-A, weight, complete blood count, scrotal and rectal temperature. Behavioural parameters included standing and lying behaviour, pen behaviour and feeding behaviour. Data were analyzed using PROC GLIMMIX (SAS), with repeated measures using mixed procedures including treatment as a fixed effect and animal and pen as a random effect. The pharmacokinetic profile of the drug including area under the curve, volume of distribution and clearance was greater (P < 0.05) in PO than SC calves. After surgery, substance P concentrations, white blood cell counts (WBC), weight and lying duration were greater (P < 0.05) in PO than SC calves, while scrotal circumference was lower (P < 0.05) in PO calves than SC calves. Although statistical differences were observed for pharmacokinetic, physiological and behavioural parameters differences were small and may lack biological relevance.info:eu-repo/semantics/publishedVersio

Effect of meloxicam and lidocaine administered alone or in combination on indicators of pain and distress during and after knife castration in weaned beef calves

To assess the effect of meloxicam and lidocaine on indicators of pain associated with castration, forty-eight Angus crossbred beef calves (304 ± 40.5 kg of BW, 7–8 months of age) were used in a 28 day experiment. The experiment consisted of a 2 × 2 factorial design where main factors included provision of analgesia and local anaesthesia. Analgesia consisted of: no-meloxicam (N; n = 24) single s.c. administration of lactated ringer’s solution and meloxicam (M; n = 24) single dose of 0.5 mg/kg of s.c. meloxicam. Local anesthesia consisted of: no-lidocaine (R; n = 24) ring block administration of lactated ringer’s solution or lidociane (L; n = 24) ring block administration of lidocaine. To yield the following treatments: no meloxicam + no lidocaine (N-R; n = 12), no meloxicam + lidocaine (N-L; n = 12), meloxicam + no lidocaine (M-R; n = 12) and meloxicam + lidocaine (M-L; n = 12). Salivary cortisol concentrations were lower (lidocaine × time effect; P 0.05) were observed for average daily gain (ADG), weights or feeding behaviour. Overall, both lidocaine and meloxicam reduced physiological and behavioural indicators of pain. Although there was only one meloxicam × lidocaine interaction, lidocaine and meloxicam reduced physiological and behavioural parameters at different time points, which could be more effective at mitigating pain than either drug on its own.info:eu-repo/semantics/publishedVersio

Energy Reallocation to Breeding Performance through Improved Nest Building in Laboratory Mice.

Mice are housed at temperatures (20-26°C) that increase their basal metabolic rates and impose high energy demands to maintain core temperatures. Therefore, energy must be reallocated from other biological processes to increase heat production to offset heat loss. Supplying laboratory mice with nesting material may provide sufficient insulation to reduce heat loss and improve both feed conversion and breeding performance. Naïve C57BL/6, BALB/c, and CD-1breeding pairs were provided with bedding alone, or bedding supplemented with either 8g of Enviro-Dri, 8g of Nestlets, for 6 months. Mice provided with either nesting material built more dome-like nests than controls. Nesting material improved feed efficiency per pup weaned as well as pup weaning weight. The breeding index (pups weaned/dam/week) was higher when either nesting material was provided. Thus, the sparing of energy for thermoregulation of mice given additional nesting material may have been responsible for the improved breeding and growth of offspring

Heat or Insulation: Behavioral Titration of Mouse Preference for Warmth or Access to a Nest

In laboratories, mice are housed at 20–24°C, which is below their lower critical temperature (≈30°C). This increased thermal stress has the potential to alter scientific outcomes. Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress. Nesting behavior should change with temperature and material, and the choice between nesting or thermotaxis (movement in response to temperature) should also depend on the balance of these factors, such that mice titrate nesting material against temperature. Naïve CD-1, BALB/c, and C57BL/6 mice (36 male and 36 female/strain in groups of 3) were housed in a set of 2 connected cages, each maintained at a different temperature using a water bath. One cage in each set was 20°C (Nesting cage; NC) while the other was one of 6 temperatures (Temperature cage; TC: 20, 23, 26, 29, 32, or 35°C). The NC contained one of 6 nesting provisions (0, 2, 4, 6, 8, or 10g), changed daily. Food intake and nest scores were measured in both cages. As the difference in temperature between paired cages increased, feed consumption in NC increased. Nesting provision altered differences in nest scores between the 2 paired temperatures. Nest scores in NC increased with increasing provision. In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C. Mice transferred material from NC to TC but the likelihood of transfer decreased with increasing provision. Overall, mice of different strains and sexes prefer temperatures between 26–29°C and the shift from thermotaxis to nest building is seen between 6 and 10 g of material. Our results suggest that under normal laboratory temperatures, mice should be provided with no less than 6 grams of nesting material, but up to 10 grams may be needed to alleviate thermal distress under typical temperatures

A New Format for Learning about Farm Animal Welfare

Farm animal welfare is a knowledge domain that can be regarded as a model for new ways of organizing learning and making higher education more responsive to the needs of society. Global concern for animal welfare has resulted in a great demand for knowledge. As a complement to traditional education in farm animal welfare, higher education can be more demand driven and look at a broad range of methods to make knowledge available. The result of an inventory on “farm animal welfare,” “e-learning,” “learning resources,” and “open educational resources” in three different search engines is presented. A huge amount of information on animal welfare is available on the Internet but many of the providers lock in the knowledge in a traditional course context. Only a few universities develop and disseminate open learning resources within the subject. Higher education institutions are encouraged to develop open educational resources in animal welfare for the benefit of teachers, students, society, and, indirectly, animal welfar