| 1. |
- Detmann, Edenio
(author)
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Effect of pre- and post-weaning supplementation on performance, nutritional, and metabolic characteristics in Nellore heifers under grazing
- 2022
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 62, s. 1706-1719
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Journal article (peer-reviewed)abstract
- Context. Supplementation during the pre- and post-weaning periods is essential to improve the development of beef heifers in tropical pastures. Especially during the dry period, performance of heifers is limited due to low forage yield and poor nutritional value. Aim. Evaluate the effect of supplementation during pre- and post-weaning periods on performance, nutritional, and metabolic characteristics in Nellore heifers under grazing. Methods. Fifty-four Nellore heifers were randomly divided between the following four supplementation plans, with two replicates: NN, not supplemented in the pre- and post-weaning dry period; NS, not supplemented in the pre-weaning period and supplemented in the post-weaning dry period; SN, supplemented in the pre-weaning period and not supplemented in the post-weaning dry period; and SS, supplemented in the pre- and post-weaning dry periods; with 14, 13, 13 and 14 calves in each treatment respectively. In the post-weaning dry-to-rainy transition period, all heifers were supplemented. Key results. Supplementation increased (P < 0.05) the intake of dry matter and crude protein on Day 56 (pre-weaning phase) and Day 168 (post-weaning dry period). Heifers supplemented during the pre-weaning phase had a higher final body weight (fBW) and average daily gain (ADG) on Day 112 (P < 0.05). Heifers NS and SS had higher fBW and ADG on Day 224 (P < 0.05). On Day 280, fBW were higher (P < 0.05) for heifers NS and SS. Insulin-like growth factor I was higher for heifers supplemented in the pre-weaning period on Day 112, and higher for NS and SS heifers on Day 224 (P < 0.05). Albumin concentrations were higher (P < 0.05) for heifers NS and SS on Day 280. Supplementation had no effect on either corpus luteum presence or concentration of progesterone (P > 0.05). Conclusions. Supplementation during either pre- or post-weaning phases improved multiple performance, nutritional, and metabolic characteristics. The results due to supplementation post-weaning were independent of supplementation pre-weaning. However, supplementation did not result in an improved response to the puberty induction protocol used in this experiment.
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| 2. |
- Fahlman, Åsa
(author)
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Physiological and behavioural effects of hypoxemia in reindeer (Rangifer tarandus) immobilised with xylazine-etorphine
- 2011
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 51, s. 355-358
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Journal article (peer-reviewed)abstract
- This study examined the physiological effects of xylazine-etorphine (XE) immobilisation in reindeer (Rangifer tarandus), as well as post-immobilisation recovery and behaviour. Six reindeer weighing 105 +/- 18 kg (mean +/- s.d.) were immobilised via remote delivery of XE into the hind limb musculature. The animals were immobilised for 30 min on two separate occasions, and a randomised crossover design was used to assign nasal oxygen (O(2)) or unsupplemented air to each animal. Arterial blood gases were collected and analysed at zero (time of arterial catheter placement), 5, 10, 20 and 30 min. Heart rate and respiratory rate, temperature, and arterial blood pressure were monitored every 5 min. After 30 min, immobilisation was reversed with naltrexone hydrochloride and tolazoline hydrochloride. The animals underwent behavioural testing (time required to navigate a novel maze) to assess cognitive function pre- and post-immobilisation. Significantly higher arterial O(2) tension levels were seen in O(2)-supplemented animals (range 95-313 mmHg) compared with unsupplemented animals (range 26-70 mmHg). Hypoxemic animals had elevated heart rates and lactate levels compared with normoxemic. Immobilisation had a significant effect on the animals' ability to navigate a novel maze.
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| 3. |
- Felleki, Majbritt
(author)
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Joint estimation of (co) variance components and breeding values for mean and dispersion of days from calving to first service in Holstein cow
- 2017
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 57, s. 760-766
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Journal article (peer-reviewed)abstract
- The present study explored the possibility of selection for uniformity of days from calving to first service (DFS) in dairy cattle. A double hierarchical generalised linear model with an iterative reweighted least-squares algorithm was used to estimate covariance components for the mean and dispersion of DFS. Data included the records of 27113 Iranian Holstein cows (parity, 1-6) in 15 herds from 1981 to 2007. The estimated additive genetic variance for the mean and dispersion were 32.25 and 0.0139; both of these values had low standard errors. The genetic standard deviation for dispersion of DFS was 0.117, indicating that decreasing the estimated breeding value of dispersion by one genetic standard deviation can increase the uniformity by 12%. A strong positive genetic correlation (0.689) was obtained between the mean and dispersion of DFS. This genetic correlation is favourable since one of the aims of breeding is to simultaneously decrease the mean and increase the uniformity of DFS. The Spearman rank correlations between estimated breeding values in the mean and dispersion for sires with a different number of daughter observations were 0.907. In the studied population, the genetic trend in the mean of DFS was significant and favourable (-0.063 days/year), but the genetic trend in the dispersion of DFS was not significantly different from zero. The results obtained in the present study indicated that the mean and uniformity of DFS can simultaneously be improved in dairy cows.
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| 4. |
- Hernández, Adalinda, et al.
(author)
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Cattle welfare aspects of production systems in the tropics
- 2022
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 62, s. 1203-1218
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Research review (peer-reviewed)abstract
- There is a growing demand for animal products, especially food for human consumption, including in developing countries in tropical regions of the world. Simultaneously, animal welfare and a reduced environmental impact are increasingly important to modern consumers and non-consumers. Increased efficiency of existing animal production systems is key to meeting the growing demand of animal products without ignoring societal concerns. Adequate animal welfare can play an important role in improving production and addressing consumer demands. This review describes the main cattle production systems in the tropics and considers how they meet the need for transparent animal welfare conditions. Several challenges to overcome are highlighted, including lack of information about the real cattle welfare status in the tropics. Adequate assessment protocols and improvements in animal nutrition, infrastructure, animal health and farming-related education need special attention in the region. Better animal welfare could improve tropical animal production in terms of productivity, and increase the volume of meat and milk delivered. It could also guarantee consumer acceptance and future consumption of animal products, secure incomes, alleviate poverty and reduce migration to urban areas and countryside abandonment.
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| 5. |
- Hjalmarsson, Fanny, et al.
(author)
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Effect of low light intensity at night on cow traffic in automatic milking systems
- 2014
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 54, s. 1784-1786
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Journal article (peer-reviewed)abstract
- Several studies have shown benefits of long-day (16 h) photoperiod in lactating dairy cows, but have not identified a suitable light intensity for the dark hours. It is known that the locomotion pattern of dairy cows is altered at low light intensities and this may translate to reduced cow traffic and milking frequency, which would have a negative impact on system productivity. However, it is also recognised that a significant disturbance of rest may have a negative impact on the health and productivity of high-yielding dairy cows. This study examined the effect of three different night-time light intensities (LOW: 11 +/- 3, MED: 33 +/- 1 and HIGH: 74 +/- 6 lx) on number of gate passages, milking frequency and milk yield in dairy cows in automatic milking systems. The study was conducted in Sweden during the winter of 2012-13 and the treatments were applied in a crossover design to three herds with an automatic milking system. Minimum day time light intensity was 158 lx. Data on gate passages, milking frequency and milk yield for 172 +/- 49 (mean +/- s.d.) cows during the last 22 days of each 34-day study period were analysed for treatment differences and differences in daily distribution over 24 h, during day time and night time. Light intensity did not affect total number of gate passages per 24-h period and cow, but number of gate passages per hour and cow was in all treatments lower during night time than during day time. Milking frequency was increased in MED compared with both HIGH and LOW (P < 0.05). Milk yield decreased with reduced light intensity, and differed significantly between HIGH and LOW treatments, 45 +/- 1 kg and 44 +/- 1 kg, respectively (P < 0.001). Our conclusion is that reducing light intensity to 11 lx at night time does not affect cows' general activity as gate passages remained the same for all treatments. However, milk yield decreased with reduced light intensity, which might be related to a lower feed intake. We argue that providing night light for dairy cows, as required by many welfare acts, might be related to production level rather than welfare aspects and that the recommendations should be revised.
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| 6. |
- Huhtanen, Pekka, et al.
(author)
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Effects of ruminal digesta retention time on methane emissions: a modelling approach
- 2016
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 56, s. 501-506
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Journal article (peer-reviewed)abstract
- The reasons for among-animal variations in methane (CH4) emissions are not fully understood. There is experimental evidence that ruminal digesta mean retention time (MRT) can affect CH4 emissions. The objective of the present study was to evaluate the contribution of among-animal variations in MRT on CH4 emissions and nutrient supply for dairy cow (default MRT = 34 h) and sheep (default MRT = 41 h), using the mechanistic Nordic dairy cow model Karoline. The simulations (n = 100) were made for a cow (bodyweight 600 kg) and for a sheep (bodyweight 60 kg) eating 20 kg and 1.0 kg DM/day, respectively. The diet for the dairy cow consisted of grass silage, barley and rapeseed meal (60:30:10 on a DM basis; crude protein 156 g/kg DM, neutral detergent fibre 450 g/kg DM) and the sheep diet was grass alone. Normal distribution of MRT values was assumed. Variability (coefficient of variation (CV) = 0.086) on default MRT was introduced by random-number generator of Excel. Intake, diet composition and digestion kinetic parameters were constant in all simulations, only ruminal MRT variables were changed in each simulation. Predicted CH4 emission increased with increased MRT for dairy cow (range from 407 to 488 g/day) and sheep (from 25.0 to 29.2 g/day). Increases in predicted CH4 emissions were partly associated with enhanced organic matter (OM) digestibility in dairy cow (from 0.715 to 0.758) and sheep (from 0.731 to 0.773). Greater CH4 emissions per kilogram digested OM with increased MRT were mainly related to reduced efficiency of microbial cell synthesis in the rumen both for dairy cows (22.8 +/- 0.91 g N/kg OM truly digested; CV = 0.040) and for sheep (20.7 +/- 0.92 g N/kg OM truly digested; CV = 0.044). Predicted CH4 yield was 20% and 17% greater in dairy cow and sheep, respectively, with the short (n = 10) compared with the long (n = 10) ruminal digesta MRT. Linear regression indicated that CH4 emissions increased by 0.37 (dairy cow) and 0.33 (sheep) g/kg DM intake per 1 h increase in ruminal digesta MRT. It is concluded that among-animal variation in MRT can markedly contribute to among-animal variation in CH4 emissions from ruminants.
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| 7. |
- Parsons, David
(author)
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A regional model of sheep lice to study the effect on lice prevalence and costs for Australian farms using a range of treatment efficacy in combination with other lice control strategies
- 2017
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 57, s. 1931-1939
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Journal article (peer-reviewed)abstract
- Using a previously developed predictive model, three different management practices were examined in combination with post-shearing chemical treatments for lice, to determine which combinations could provide costeffective reductions in lice prevalence over a 20-year period. The model included nine sheep production regions across Australia, all of which have different regional flock prevalence of lice and mean numbers of sheep/property. The lice prevalence model simulated the effects of four management options on Australian lice prevalence and on financial return (expressed as net present value) over a 20-year period. Management options modelled in this study were: treatment for eradication, inspection for lice detection, intervention level, and biosecurity of purchased sheep. The costs and benefits of these management options were calculated on the basis of published data or standard industry costs. Combinations of eradication achieved through treatment and biosecurity of purchased sheep provided the greatest modelled reductions in Australian flock lice prevalence at the lowest cost. With current management practices, lice prevalence was estimated as 16.3% of Australian properties infested and lice costs were estimated at 902 cents per sheep over 20 years. The model estimated that with appropriate management, lice prevalence could be reduced to less than 1.5% of properties infested and costs could be halved to 435 cents per sheep over 20 years. With further development, the modelling described herein offers potential guidance for Australian sheep producers in selecting the most effective and cost-efficient combination of management strategies to reduce lice infestation.
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| 8. |
- Samkol, Pok, et al.
(author)
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Effects of supplementing low-quality hay with groundnut foliage and cassava tops on feed intake, apparent digestibility and rumen fermentation in crossbred cattle
- 2019
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 59, s. 1660-1666
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Journal article (peer-reviewed)abstract
- Four adult crossbred cattle, fitted with rumen fistula in the dorsal sac, were randomly allocated to four treatments in a 4 x 4 Latin-square design to study the effects of supplementing sun-dried groundnut (Arachis hypogea L.) foliage (DGF) and sun-dried cassava (Manihot esculenta, Crantz) tops (DCT) on feed intake, apparent digestibility and rumen fermentation. All animals were fed a basal diet of rice straw ad libitum and para grass (Brachiaria mutica) at 1% of liveweight (LW). The four experimental diets were as follows: (1) control, basal diet without supplement; (2) DGF, basal diet + DGF; (3) DCT, basal diet + DCT; and (4) DGF+DCT, basal diet + DGF + DCT. The supplementary feeds were fed to the level of 2 g crude protein (CP)/kg LW in Diets 2 and 3 and 1 g CP/kg LW of each feed in Diet 4. The results indicated that total intake of dry matter (DM), organic matter and CP increased with DGF and DGF+DCT diets, while neutral detergent fibre (NDF) intake was highest in the DGF diet. Digestibilities of DM, organic matter, CP and NDF were improved in DGF and DGF+DCT treatments. However, the diet with DCT supplement had lowest CP and NDF digestibility. Ruminal NH3-N and total volatile fatty acids increased in all diets with supplements, but ruminal pH, volatile fatty acid profile and in sacco losses of DM, CP and NDF of sun-dried para grass in the rumen did not differ among the treatments.
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| 9. |
- Solé Berga, Marina
(author)
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Evidence for the effect of serotoninergic and dopaminergic gene variants on stress levels in horses participating in dressage and harness racing
- 2019
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In: Animal Production Science. - 1836-0939 .- 1836-5787. ; 59, s. 2206-2211
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Journal article (peer-reviewed)abstract
- Eye temperature assessed with infrared thermography is an adequate tool for stress level assessment in sport horses' competitions having a moderate heritability. Serotonin and dopamine signal transduction-linked gene variants have been associated with anxiety-related traits in several species. In this study we examined the association between 10 gene variants in BDNF, COMT, HTR1A, TPH2 and SLC6A4 genes (and the haplotypes at SLC6A4 gene) with stress level (measured with eye temperature and heart rate) in 270 animals, 135 Spanish Trotter Horses (STH) participating in trotting races and 135 'Pura Raza Espanol' (PRE) horses in dressage. Association analyses were performed using a unified mixed model (counting for population structure and individual relatedness) for the whole population and for each horse breed. The g.43865600G > A intronic gene variant located 11.0 kb downstream from the transcription start site of SLC6A4 gene was associated with an increase in eye temperature before competition with a relative contribution of this gene variant of 38.8% (P = 0.001), 31.8% just after (P = 0.001) and 29.8% 2 h after the competition (P = 0.003). In STH, the g.43865600G > A gene variant showed the same association with eye temperature before (P = 0.001, contribution 27.2%), just after (P = 0.0003, 29.0%) and after the competition (P = 0.002, 17.5%); and the c.*111G > A gene variant located at the 3'UTR region of COMT gene was associated with eye temperature 2 h after the competition (P = 0.001, 22.3%). These results showed that SLC6A4 and COMT gene variants are associated with stress level measured as eye temperature increase during competitions, and may be promising tools for genetic testing against resistance at high stress levels in trotter horses.
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| 10. |
- Edwards, M. V., et al.
(author)
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Spray-dried porcine plasma and yeast derived protein meal influence the adaption to weaning of primiparous and multiparous sow progeny in different ways
- 2013
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In: Animal Production Science. - 1836-5787. ; 53:1, s. 75-86
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Journal article (peer-reviewed)abstract
- Pigs from 154 litters (n = 1132, 19 +/- 3 days of age, 4.9 +/- 1.1 kg of bodyweight) were used in a 3 x 2 factorial design to evaluate two raw materials with nutraceutical properties being used in feeds, spray-dried porcine plasma (SDPP) and a yeast protein meal, and their effects on growth performance, immune parameters and gastrointestinal adaption of piglets to weaning. Factors included dietary treatments being (1) 5% SDPP (PLA), (2) 3.5% yeast protein meal (NUP) and (3) medicated control (TMC) and parity (primiparous versus multiparous). The treatment groups were imposed from Day 19 through to weaning at Day 27. Selected pigs (n = 720, 28 +/- 3 days of age, 7.4 +/- 1.0 kg of bodyweight) were weaned and remained on their respective diets from Day 28 to Day 34. From Day 35 to Day 48 all group-housed pigs were offered a commercial weaner 1 diet, and from Day 49 to Day 68 pigs were offered a commercial weaner 2 diet. Growth performance, survival, and serum immunoglobulinGwere monitored throughout the nursery phase (Day 28 to Day 68). Adaptation of the gastrointestinal tract in the acute post-weaning phase (Day 28 to Day 34) was assessed in 36 individually housed male weaners, with the effects of feed on structural, digestive, microbial and immune parameters along the gastrointestinal tract determined atDay 34. Pre-weaning feed disappearance was greater (P< 0.01) in multiparous litters independent of diet. In the commercial nursery, total removals (mortality and morbidity) were highest (P<0.01) in primiparous sow progeny, with pigs offered NUP having greater (P <= 0.05) total removals. Pigs offered PLA had superior average daily gain, average daily feed intake and feed conversion ratio from Day 28 to Day 34 (P<0.05). Pigs offered NUP tended to (P=0.07) have superior average daily gain from Day 35 to Day 49. Pigs offered NUP had higher (P<0.05) serum immunoglobulinGconcentrations at Day 68 compared with pigs offered TMC, with the effect most pronounced in primiparous sow progeny. Individually housed weaners offered PLA consumed more (P<0.05) feed on Day 30 to Day 31, had shorter relative intestine length (P<0.05), greater villous height in the medial jejunum (P<0.10) and lower immuno-pathology scores along the intestine. Pigs offered PLA also tended (P<0.10) to have increased pancreatic-specific lipase and amylase activity compared with pigs offered NUP. Pigs offered NUP had a higher ratio of E. coli : coliforms in the colon (P<0.01) and more counts of beta-haemolytic bacteria in the medial jejunum (P<0.05) and colon (P<0.10). Diets containing either SDPP or NUP offered pigs benefits beyond nutrition relative to the medicated control diet. The benefits of SDPPwere highly effective but transient, while the yeast derived protein had a successive or accumulative effect which was more pronounced in primiparous sow progeny. Received 3 May 2012, accepted 17 October 2012, published online 29 November 2012
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