a Universite d’Abomey Calavi Faculte des Sciences Agrononomiques Departement des Productions Animales01 BP 526 Cotonou, Republique du Benin. b Universite de Liege Faculte de Medecine Veterinaire Departement des Productions Animales. Bât B 43, 20 Boulevard de Colonster, 4000 Liege Belgique. c Direction de l’Elevage, Projet pour le developpement de l’Elevage, Ferme d’Elevage de Betecoucou Republique du Benin. d Ecole Inter Etat des Sciences et Medecine Veterinaires. BP : 5077 Dakar. Senegal.
Different methods of estimating weight gain were compared for accuracy and utility, using the amount of error variation from fitting the residual feed intake (RFI) model. Data were collected on 1481 cattle of temperate and tropically adapted breeds, feedlot-finished for the domestic (liveweight 400 kg), Korean (520 kg), or Japanese (steers only; 600 kg) markets. Cattle were tested in 36 groups over 4 years. The aim was to estimate weight gain over the period feed intake was measured, which was at least 49 days and averaged 63 days, including time for animals to adapt to the automatic feeding system. The different estimates were derived from linear and quadratic regressions of weight over time fitted to: F I) all weighings in the feedlot and F2) all weighings in the feedlot excluding atypical records in the first few weeks following feedlot entry. More complex linear and quadratic models were also fitted to weighings when feed intake was being measured, using the amount of feed eaten on the day of weighing, and previous days, to adjust for gut fill. Finally, a random regression model including general trends in the growth of each animal and short term measurement error was fitted to dataset F2 to estimate weight gain for the period feed intake was measured.The RFI equation: feed intake=intercept(s)+beta(w) * mean(weight(0.73))+beta g* weight weight gain+error (i.e. RFI) was fitted using the different weight gain estimates. Based on mean squared errors from fitting this equation, longer measurement periods generally resulted in more accurate estimates of weight gain. The increased accuracy from using all weight measurements in the feedlot outweighed the loss from not measuring over the desired time interval-i.e. the period for which feed intake was measured. Crown Copyright (c) 2005 Published by Elsevier B.V All rights reserved.
This study evaluates the effect of dry-season concentrate supplementation on growing cattle performance grazing tropical pasture and the impact of nitrogen fertilization on the growth rate of tropical pasture (tons of dry herbage mass/ha/110 days) and on the subsequent stocking rate and cattle performance during the rainy season (kg body weight gain/ha/110 days). The animal and plant responses were curvilinear to the increasing amount of nutrient supply and followed the typical saturation kinetics of enzyme systems, a Michaelis–Menten relationship. The Lineweaver–Burk data transformation explained efficiently the animal and plant responses to the nutrient supply. This methodology consists in evaluating the linear regressions of the reciprocal of animal and plant responses as a function of the reciprocal of nutrient supply. The half maximum growth rates for plant and animal to nutrient supply were verified with the proportions from .048 to .056 of the amount needed to cause .95 of theoretical maximum responses. From the curvilinear response, it can be verified that the marginal increase in animal and plant growth rate reduces as the amount of nutrient supply increases.
Mammary gland infection induces an inflammatory reaction which causes an increase of somatic cells in milk and activation of bacteriostatic enzymes and proteins in milk. It has been demonstrated that during spontaneously occurring subclinical mastitis the somatic milk cells, mainly macrophages, secrete cytokines, eicosanoids, acute phase proteins and other immunomediators. In contrast, the bacteriostatic protein lactoferrin is mainly secreted by mammary epithelial tissue, while major milk proteins like a-lactalbumin and K-Casein are down-regulated already during subclinical infection. In LPS-challenged quarters, tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and cyclooxygenase-2 expression increased to highest values at 3 h after LPS-challenge. Expression of lactoferrin, lysozyme, inducible nitric oxide synthase, L-selectin, NF kappa B and of the apoptotic factors caspase-3, caspase-7 and Fas (FS-7 associated surface antigen) was elevated and peaked at 6 It after challenge. No significant increase in expression of platelet-activating factor, acethylhydrolase, 5-lipoxygenase, p-integrin and insulin-like growth factor I was found. In the control quarters, only TNF-alpha, IL-1 beta and lysozyme increase slightly and much less than in LPS-challenged quarters whereas the other parameters tested did not change significantly. Gene expression of major milk proteins did not change significantly in response to the LPS challenge (alpha S1-casein (CN), alpha S2-CN, beta-CN and beta-lactoglobulin) except for alpha-lactalbumin which decreased in LPS-treated and control quarters and for kappa-CN which decreased in the LPS-treated quarters. In conclusion, gene expression of the majority albeit not all inflammatory factors changed within hours of LPS challenge. Decreased gene expression of alpha-lactalbumin and kappa-CN may reduce milk yield and suitability for cheese production. (c) 2005 Elsevier B.V. All rights reserved.
During the past two decades significant advances have been made in understanding the importance of an adequate vitamin status in dairy cows based on improved nutrition. These progresses have substantially re-defined the meaning of vitamins as essential signalling molecules or cofactors that allow animals to sustain health and production. For this reason the concept of optimum vitamin requirements for animals under intensive livestock conditions has been developed. The intensive research interest in vitamin E stems from its potential role as an antioxidant that is able to prevent free-radical mediated tissue damage. Vitamin E also seems to be crucially involved in immune system function, so that supplementation with supra-nutritional levels of the vitamin, in some instances, results in improved immune responses. This article will provide an overview of current knowledge of vitamin E in dairy cows, including an assessment of lesser known and still only partially elucidated effects on efficiency of absorption and transport to target tissues, and uptake and function at the cellular and molecular levels.
To evaluate the effects of a dietary supplementation with biotin on heavy pigs' productive performances (including meat and cured hams quality), 45 Landrace x Large White barrows with an initial average body weight (BW) of 35 kg were allocated to three experimental groups: a control group (A) fed with a maize/soybean diet and two treatment groups (B and C) receiving the same diet as group A but with the addition of crystalline biotin at 150 and 300 ppb, respectively. Pigs were fed at the rate of 9% of their metabolic BW (BW0.75) up to a maximum of 3.2 kg/pig per day. Pigs were slaughtered at about 160 kg BW Animals on biotin diets showed a higher (P < 0.05) average daily weight gain (ADG) during the finishing phase. The addition of biotin to the diet resulted in lower L* and hue values of loin (P < 0.05). The dietary treatment significantly affected the fatty acid composition of the subcutaneous fat of the fresh thigh, resulting in an increase of saturated acids and in a lowering of the sum of unsaturated acids and the iodine number in biotin-treated animals (P < 0.05). Our results indicate that biotin may play a positive role on heavy pigs' growth, meat quality and the sensory and technological properties of cured hams. (c) 2004 Elsevier B.V. All rights reserved.
The aim of the study was to delineate the components of the galactopoietic effect of milking in lactating cows. After individual determination of oxytocin physiological injection doses, eight Holstein cows were assigned to treatments over a 5–10-day period: two daily milkings (TD) as control, four daily milkings to measure the effect of additional milking, TD+two oxytocin injections to measure the oxytocin effect without milking, TD+two milkings after Atosiban (oxytocin receptor-blocking agent) injections to measure the effect of milking alone (i.e., without the oxytocin effect), TD+two udder emptyings via cannula and oxytocin injection to measure the effect of milking with a limited systemic hormonal discharge other than oxytocin. Daily milk yields, milk composition and plasmatic oxytocin and prolactin concentrations were measured. Additional milking increases milk production by 8% (P<0.05) and total milk constituents by 6%, confirming its galactopoietic effect. Injections of physiological doses of oxytocin induce an intermediate galactopoietic effect between the twice and four daily milkings, but only when accompanied by milk removal. This shows that the prevention of alveolar milk stasis is essential to measure the galactopoietic effect. The limitation of systemic hormonal release, other than oxytocin, during additional milking increases milk production by only 4.4% (not significant), suggesting a limited role of systemic hormones for the expression of the galactopoietic effect of milking compared to oxytocin. An additional role of oxytocin on mammary epithelium, coexpressed with alveoli emptying, cannot be excluded.
To study the differences in meat yield in hypertrophied cattle, a commercial dissection trial was carried out on 48 carcasses obtained from 24 Piemontese (P: 12 reared with a restricted feeding, P-R, and 12 fed ad libitum, P-L), and 24 Belgian Blue (B: 12 reared with a restricted feeding, BB-R, and 12 fed ad libitum, BB-L) young bulls. The animals were reared under the same environmental condition and slaughtered at the same age and fattening degree. During commercial dissection, the weights of the retail cuts were recorded. Three fore-quarter meat cuts were heavier in P than in BB, while nine meat cuts (two from fore-quarter and seven from hind-quarter), hind-quarter meat and prime quality meat were heavier in BB than in P. Fat weight was higher in BB than in P, whereas meat production as a percentage of carcass side weight was higher in P than in BB. Only one hind-quarter meat cut was heavier in the ad libitum (L) than in the restricted (R) group, whereas meat yield was higher in R than in L. In comparing the meat yield in carcass sides of P-R, P-L, BB-R and BB-L fed young bulls, four meat cuts (one from fore-quarter and three from hind-quarter), hind-quarter, prime quality and 3rd quality meat were heavier in BB-L (P≤0.05), while one shoulder cut and fore-quarter were heavier in P-R group.
In coping with the effects of high temperatures, the movement of performance horses from temperate to tropical and sub-tropical regions places major demands on their animals metabolic and cooling systems. Without acclimation, high temperatures increase body core temperature, sweating, metabolic rate, and alter the rate at which glucose and lipids are metabolized. These effects appear to be transitory, as the animal's metabolism returns to near temperate metabolism after 2–3 weeks of acclimatization. High temperatures also result in reduced feed intake. Feeding animals under high temperature conditions generally means keeping forage intake to a minimum and maximizing the energy density of the concentrate. A high fat concentrate is recommended because fat reduces the heat load on the animal, even though the fat may be metabolically less important than glucose. Increased sweat production will increase nitrogen loss, making additional protein intake necessary. Nevertheless, protein intake, above the animal's requirement, may have an adverse effect on body heat production. Therefore, minimizing protein intake, by the addition of appropriate amino acids, such as lysine and threonine, to the diet, may be beneficial.
The potential environmental effects of livestock farming are mainly associated with intensification of poultry, pig and dairy cow production systems. The major impacts are mainly caused by housing of livestock, which can lead to air and water pollution associated with nitrogen and phosphorus emissions and losses from manure. European countries regulate the potential for these types of pollution through a number of mechanisms, which have received wide public acceptance. In grazing systems, nitrogen pollution, associated with the use of nitrogen fertilizer, is also the subject of legislation. Perhaps because of this regulatory approach, surveys of the public have found that human food quality and animal welfare are more important issues than effects on air and water quality when considering livestock systems.Variation in stocking rates of grazing ruminants can change the structure and composition of pastures with potential impacts on biodiversity and the production of methane, a greenhouse gas. In European countries, maximum stocking rates have been set to reduce these impacts. Surveys of the European public have suggested that they are willing to pay for the mitigation of these environmental effects but that they also value strongly the cultural component of grazed livestock systems. There are few underlying concepts about how society views the environmental impacts of livestock systems. These are used to conclude that current attitudes are likely to prevail in the next decade. (c) 2005 Elsevier B.V. All rights reserved.
Morphological characteristics, coat effective radiative properties, and the percentage of white colour were measured in the coats of 973 Holstein cows, and estimates of the genetic parameters were obtained for these traits, except morphological characteristics. The results showed that white coats are more dense with long, thin hairs, while the black coats are less dense with short, thick hairs. Effective transmissivity is greater in the less-dense coats with short, thin hairs, independently of coat colour. Effective reflectivity depends more on the variation in the radiative properties of the coat and skin surface rather than on the morphological characteristics of the coat. Effective absorptivity is greater in black and dense coats with long, thick hairs, than in the white and less-dense coat with short, thin hairs. All heritability estimates were of low magnitude, except for the percentage of white coat colour.
N and P surpluses per hectare at farm level were determined on 63 private pilot farms with data from 2 to 7 years between 1997 and 2003 (a total of 245 observations). Farms were classified in the following four farm types: Conventional mixed dairy, organic mixed dairy, conventional pig farms (indoor) and conventional pig farms with outdoor sows. Import of nutrients with concentrate and fertilizer was the major input to all conventional farm types. On the organic dairy farms major input was N fixation, but also import of nutrients with concentrate and manure were important inputs. Output from the dairy farms was dominated by nutrients in milk. On pig farms nutrients in meat dominated the output, but also export of nutrients with cash crops and manure were important outputs. Farm type, year and farm within farm type significantly affected both N and P surpluses per hectare. Farm type was the major source of variation in both N and P surpluses. In the period investigated N surplus decreased by 6.5 kg N ha−1 yr−1 and P surplus decreased by 0.7 kg P ha−1 yr−1. The N and P surpluses observed on the conventional dairy farms significantly exceeded surpluses observed on the organic dairy farms. At equal number of livestock units (LU) per hectare (1.28 LU ha−1) the difference was 43 kg N ha−1 and 6 kg P ha−1. At equal rates of N or P in manure to fields (147 kg N ha−1, 29 kg P ha−1, respectively) the difference was 45 kg N ha−1 and 4 kg P ha−1. Conventional dairy farms and pig farms with sows indoors had equal N and P surpluses at equal rates of N or P in manure to fields. Corrected to the average year (1999.5) the estimated average N and P surpluses showed highest levels on pig farms with outdoor sows (251 kg N ha−1, 42 kg P ha−1) and lowest levels on organic dairy farms (113 kg N ha−1, 7 kg P ha−1). Surpluses on the conventional dairy farms were 175 kg N ha−1 and 16 kg P ha−1 and on the indoor pig farms they were 123 kg N ha−1 and 13 kg P ha−1. The N and P surpluses observed on Danish conventional mixed dairy farms were comparable with intensive dairy farming systems in other European countries.
Milking frequencies measured at official test days were used with repeated measurement analysis to reveal the environmental and genetic impact on the milking frequency of cows in automatic milking systems. Repeated measurements were 3 test-day observations per cow within days in milk (DIM) classes, with 1,216 cows in DIM class 1 (d 0 to 99), from 1,112 cows in DIM class 2 (d 100 to 199), and from 1,004 cows in DIM class 3 (d 200 to 299) kept in 15 farms. Selection criteria for models analyzing repeated measurements were Akaike and Schwarz Bayesian values, which favored the autoregressive [AR(1)] covariance structure over the compound symmetry model. Results from the AR(1) model indicated a significant impact of fixed herd and parity effects. Milking frequencies decreased with increasing parities and were greatest for first-parity cows. High daily milk yield was associated with higher milking frequencies. Heritabilities for milking frequency were 0.16, 0.19, and 0.22 in DIM classes 1, 2, and 3, respectively, from the AR(1) model. Higher heritabilities in the later stage of lactation were due to a substantial reduction of the residual variance. Genetic correlations between test-day milk yield and daily milking frequency were in the range of 0.46 to 0.57 for all DIM classes and between milking frequency and somatic cell score were near zero. For verification of results, milking frequencies of the same cows obtained from herd management programs were averaged within DIM classes. Heritabilities were slightly above the values from the AR(1) model. In conclusion, heritabilities for milking frequency in automatic milking systems are moderate enough to incorporate this behavioral trait in a combined breeding goal. The inevitable improvement of labor efficiency in dairy cattle farming demands such cows going easily and voluntarily in automatic milking systems.
A rapid urinary iodide test was assessed in goats to validate its effectiveness in field conditions. The test provides a semiquantitative assessment of the iodine intake and could be valuable for animal population. Two hundred and forty-six dairy goats were randomized selected for this study. According to iodide content in urine, results were classified in three groups (< 10 mu g/dL, 10-30 mu g/dL, > 30 mu g/dL). These findings were in agreement with spectrophotometrical determinations and with serum iodine values. Sensibility and specificity were 89% and 78%, respectively. Data on reproducibility and interfering substances were also valuable. Given the technical simplicity, cost-effectiveness and its stability in heat environmental conditions, the rapid urinary iodide test should be considered as a valuable method for epidemiological surveys in field conditions or in development countries. (c) 2005 Elsevier B.V. All rights reserved.
Allele frequencies of a polymorphism in the αS1-casein 5′ flanking region (CSN1S1-5′) were determined in 14 Central and Eastern European cattle breeds by single strand conformation polymorphism analysis. Allele frequencies ranged from 0.00 to 0.35 (allele 1), 0.08 to 0.91 (allele 2), 0.04 to 0.41 (allele 3) and from 0.00 to 0.16 (allele 4). Allele 5 was not found. Presence of allele 2 in all breeds highlights its probable wild type status. A loss of alleles and genotypes occurred in some breeds, but differentiation within the breed groups milk, beef and dual purpose was higher than between these groups. An analysis of the variance in a German Holstein granddaughter design with family and CSN1S1-5′ genotype as fixed effects revealed significant effects (P<0.05 each) of the CSN1S1-5′ genotype on breeding values for dairy character, fore udder attachment, length of productive life and highly significant effects on somatic cell score (P<0.001). Genotype LS-means assigned favourable values for udder health and longevity to genotype 24. Past selection for milk yield or beef production does not seem to have favoured indirectly specific promoter alleles. No negative effects of genotype 24 were evident in Holstein, but selection for 23 requires careful inspection of unfavourable side effects.
Four Israeli mix-breed Saanen dairy goats were used in a 2×2 factorial design to evaluate the effect of the level of dietary crude protein (CP) and ruminally degradable OM (RDOM) concentration on the production, composition and efficiency of milk production under hot ambient conditions. Daily ration comprised of 30% hay and 70% concentrates was divided into 12 equal meals. Treatment factors were 18% (HCP) or 15% (LCP) of CP in the diet DM, and 56% (HRDOM) or 50% (LRDOM) of RDOM. Goats were housed in metabolic crates in air-conditioned room. Air temperature ranged between 25 °C and 36 °C, and the thermal humidity index (THI) between 74 and 90 units. Daily amplitude of goat's body temperature was 1.2 °C and was unaffected by treatments. The DM intake, milk yield, and concentrations of protein, fat, and lactose, as well as total tract apparent digestibility of DM and OM were similar among treatments (P>0.1). Digestibility of CP was higher in the HCP diets (P<0.01), and digestibilities of NDF was higher in the LRDOM diets (P<0.01). Digestibility of non-structural carbohydrates was higher in the high RDOM diets and high CP diets (P<0.1). Blood glucose and insulin concentrations were similar among treatments (P>0.1), while NEFA level was higher in LRDOM (P<0.1). Rumen N-ammonia (P<0.05) and milk N-urea (P<0.01) were lower, and plasma N-urea tended to be lower in LCP diets (P<0.15). Overall, these data indicate that N utilization was lowered in goats consuming the high CP diets. It was concluded that diets comprising 15% of CP in DM are adequate for dairy goats exposed to daily high environmental temperatures, and moderate temperatures at night. Though varying dietary RDOM levels did not affect milk N efficiency, the higher NSC digestibility, and the concomitant lower blood NEFA suggest a reduced heat increment in dairy ruminants consuming HRDOM diets.
The behaviour of 78 boars in three different semen-processing centres was continuously recorded for 72 h per boar, with respect to boars' age, season, management system of the semen-processing centre (AI station) and size of boar pens. During each 24-h period of observation, the boars spent, on average, 81% of their time lying, equivalent to about 19.5 h per day. Most behavioural patterns were influenced by the AI station or by the semen-processing centre×season interaction. The percentages of active lying and active plus passive lying were significantly lower and the frequency of engagement with bedding was higher (P<0.05) in one AI station compared with the other two stations. The circadian rhythm of lying behaviour and engagement with bedding was influenced by management factors, such as feeding and the provision of water and straw bedding. These differed between semen-processing centres. Pen size had only a significant influence on engagement with bedding.
As livestock production has increasingly intensified resulting in larger and more specialised farm units, the role of grassland in the production system has been marginalised. The change in EU policy, however, may make grass as feed more competitive and thereby give grassland the opportunity for a comeback. The challenge for research and grassland farming practices is to reflect this new framework. This paper reviews different production and management systems – mainly focusing on grazing systems – within intensive dairy farming and aspects of feeding and quality of herbage in order to propose areas of special interest within the new framework. Farming systems based on a high proportion of roughage, such as in organic farming, and systems based on legumes need to be further developed. There is a need for an increased research effort in the area of interaction of supplementary feeds and seasonal effects and also in the area of the interaction of N and carbohydrate degradation in the rumen with milk response and N efficiency. Additionally, time-restricted systems based on a better understanding of animal behaviour should be emphasised in order to maintain a high grass intake and reduce the excretion of nitrogen on pasture. The interaction between grassland management and new technology such as automatic milking will be important in order to keep a high proportion of the dairy cows on pasture.
Recent developments in nutrition have established that choline is an essential nutrient for mammals when a sufficient supply in methionine and folates is not available in the diet. Vitamin B12 is also involved in this process. In adult ruminants, choline is extensively degraded in the rumen; for this reason dietary choline contributes insignificantly to the choline body pool and methyl group metabolism is generally conservative with a relatively low rate of methyl catabolism and an elevated rate of de novo synthesis of methyl groups via the tetrahydrofolate system. In dairy ruminants, the dietary availability of choline is nearly non-existent, but the output of methylated compounds in milk is high while methionine as well as other sources of methyl groups are likely to be in short supply, especially at the onset of lactation. Based on those observations, the effects of rumen-protected choline (RPC) supplementation to transition cows was studied in two trials. Results obtained suggested that a greater choline availability can improve not only milk production efficiency, but also lipid and methyl group metabolism in transition dairy cows. RPC also increased plasma α-tocopherol, suggesting a novel choline–vitamin E interaction. However, the exact mechanisms underlying these findings are unclear, and choline requirements in dairy cows are still unknown. This indicates that further studies under different feeding conditions are needed.
The horse has a regulatory system which responds in a complex manner to stress, such as exercise. It supplies the fuel and ensures thermoregulation, resulting in the production of sweat. Cutaneous water and electrolyte losses are controlled by thermoregulation, independent of hydration status and/or electrolyte homeostasis. The negative balance for water Na, K and Cl may be a factor in limiting performance and impairing recovery. The strategy in caring for a horse before, during and after exercise involves improving hydration and electrolyte status and the use of NaCl as a feed or in a watery solution (iso- or hypotonic). The voluntary intake of saline is not safe for any horse. If salt is supplemented in a feed, it is essential that water be made available ad libitum. It is also important that, after salt intake, sufficient time is allowed to give the horse the opportunity to drink an adequate quantity of water. Application of K prior to exercise is not recommended. During exercise, NaCl solutions can be administered, while salty supplements are less suitable as regard the time required to stimulate water intake. After exercise, K can be added to supplements or solutions to balance the K deficit.
