Effect of milk replacer feeding program on performance of Belgian Blue double-muscled rearing calves

One hundred and four Belgian Blue double-muscled calves were divided into four groups to examine the effects of different milk replacer (MR) programs. Calves in treatment group 1 received a MR diet reconstituted at 125 g/l, fed at 10 % of their initial live weight in two meals daily. Weaning occurred abruptly at a concentrate intake of 0.5 kg/d. Treatment 2 was similar to treatment 1, except that weaning occurred at a concentrate intake of 0.75 kg/d. Treatment 3 was similar to treatment 2, except that MR was fed once daily at 5 % of initial body weight from a concentrate intake of 0.5 kg/d onwards. Treatment 4 was similar to treatment 3, except that MR at a concentration of 200 g/l was fed once daily from the third week until a concentrate intake of 0.5 kg/d. Similar concentrates and grass hay were fed. Pre-weaning gain averaged 0.51, 0.57, 0.56 and 0.53 kg/d, respectively (P < 0.05; SEM: 0.01). Daily nutrient intake was lowest for treatment 1. No effect on diarrhoea was found. Post-weaning gain did not differ among treatments. Daily gain during the whole rearing period (20 weeks) averaged 0.83 kg and was not affected by treatment. Calves assigned to treatment 1 had a lower daily intake of MR, while feed efficiency tended to be worse. Weaning can be successfully accelerated by skipping over a meal when concentrate intake exceeded 0.5 kg/d, or by combining one MR meal daily with an increased concentration of 200 g/l from an age of three weeks onwards

Performance analysis of priority queueing systems in discrete time

The integration of different types of traffic in packet-based networks spawns the need for traffic differentiation. In this tutorial paper, we present some analytical techniques to tackle discrete-time queueing systems with priority scheduling. We investigate both preemptive (resume and repeat) and non-preemptive priority scheduling disciplines. Two classes of traffic are considered, high-priority and low-priority traffic, which both generate variable-length packets. A probability generating functions approach leads to performance measures such as moments of system contents and packet delays of both classes

Belgian energy and protein feeding standards for growing and fattening cattle

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Body condition scoring in relation to changes in body weight and performance in Belgian Blue double-muscled beef cows

The relationship between the body condition in Belgian Blue double-muscled cows and the performance of cows and calves has been studied over a 5-year period. One hundred and twenty-six cows, with a mean initial parity of $1.6 \pm 1.1$ were involved. During each winter, they were fed 100, 90, 80 or 70% of their energy requirements (140-day restriction period). At the end of April, all cows were turned out on pasture in identical circumstances (re-alimentation period). Half of the cows were suckled by their offspring; the other cows were dried off following calving and colostrum collection. Body condition score (BCS; scale 0 to 5) was determined at the start and end of the restriction period and the re-alimentation period, at monthly intervals and at calving. Two hundred and thirteen parturitions were involved, of which 63% occurred during the first half of the year. BCS (mean of monthly observations) was lower ($P < 0.001$) in primiparous (1.45) cows than in cows with two (1.69) or more parturitions (1.81). BCS (mean of monthly observations) was lower in suckling cows (1.51) than in dry cows (1.79; $P < 0.001$). BCS (mean of monthly observations) was reduced by energy restriction from 1.75 to 1.56 ($P < 0.001$). BCS-change during the restriction and re-alimentation periods was related to body weight change (R$^{2} = 0.538$). BCS-change was negative during the restriction period, but it was more than compensated for during the re-alimentation period. BCS at calving was not related to the length of the subsequent calving interval. Cows with a BCS less than 1.5 at calving, yielded less milk and calf performance was reduced when compared with those with a BCS over 1.5. The dams of calves that died at birth had a lower BCS at calving (1.45) than the dams of surviving calves (1.75; $P = 0.044$). Open cows at 9 months postpartum had a higher BCS at calving (1.78) than cows that became pregnant within 9 months postpartum (1.50; $P < 0.001$). Consequently, it is difficult to define a universal optimum BCS for double-muscled cows, resulting in a maximal milk production and calf growth, a low calf loss and cow culling rate and a calving interval of approximately one year.
Relation entre la note d'état d'engraissement et les performances des vaches Blanc Bleu Belge culardes. La relation entre la note d'état d'engraissement (NEE) des vaches et les performances des vaches et des veaux a été vérifiée avec cent vingt-six vaches Blanc Bleu Belge culardes pendant cinq années. Les animaux avaient une parité moyenne de $1{,}6 \pm 1{,}1$ au début. Pendant chaque hiver, elles ont été affouragées à 100, 90, 80 ou 70 % de leurs besoins énergétiques (140 jours ; période de restriction). Toutes les vaches ont été mises au pâturage dans des conditions identiques à partir de la fin avril (période de compensation). La moitié des vaches ont allaité leur veau, tandis que les autres vaches ont été taries après collection du colostrum. La NEE (0–5) était déterminée au début et à la fin de la période de restriction et de la période de compensation, chaque mois et aussi au moment du vêlage. Il y avait 213 vêlages, dont 63 % pendant la première moitié de l'année. La NEE (moyenne des observations) était plus faible ($P < 0{,}001$) chez les primipares (1,45) que chez les vaches à deux (1,69) ou plus de vêlages (1,81). La NEE (moyenne des observations) était plus faible chez les vaches allaitantes (1,51) que les vaches taries (1,79 ; $P < 0{,}001$). La NEE (moyenne des observations) a été réduite de 1,75 à 1,56 par une restriction énergétique ($P < 0{,}001$). Le changement de la NEE pendant les périodes de restriction ou de compensation était lié au changement du poids (R$^{2} = 0{,}538$). Le changement de la NEE était négatif pendant la période de restriction, mais il était plus que compensé pendant la période de compensation. La NEE au vêlage n'était pas clairement liée avec l'intervalle vêlage-vêlage suivant. Une NEE au vêlage inférieure à 1,5 a diminué la production laitière et la croissance des veaux. La NEE au vêlage des mères des veaux morts à l'âge de 16 semaines (1,45) était plus faible que chez les mères des veaux en vie (1,75 ; $P = 0{,}044$). Les vaches non-gestantes 9 mois après le dernier vêlage avaient une NEE au vêlage plus élevée (1,78) que les vaches en gestation 9 mois après le dernier vêlage (1,50 ; $P < 0{,}001$). Par conséquent, il est difficile de définir une NEE optimale universelle pour les vaches culardes, qui conduise à une production laitière et une croissance du veau maximales, des taux faibles de mortalité des veaux et de reforme des vaches, et un intervalle vêlage-vêlage d'à peu près un an.

Maintenance Energy Requirements of Double-Muscled Belgian Blue Beef Cows

Sixty non-pregnant, non-lactating double-muscled Belgian Blue (DMBB) cows were used to estimate the energy required to maintain body weight (BW). They were fed one of three energy levels for 112 or 140 days, corresponding to approximately 100%, 80% or 70% of their total energy requirements. The relationship between daily energy intake and BW and daily BW change was developed using regression analysis. Maintenance energy requirements were estimated from the regression equation by setting BW gain to zero. Metabolizable and net energy for maintenance amounted to 0.569 ± 0.001 and 0.332 ± 0.001 MJ per kg BW0.75/d, respectively. Maintenance energy requirements were not dependent on energy level (p &gt; 0.10). Parity affected maintenance energy requirements (p &lt; 0.001), although the small numerical differences between parities may hardly be nutritionally relevant. Maintenance energy requirements of DMBB beef cows were close to the mean energy requirements of other beef genotypes reported in the literature

Effect of energy density of diets for intensive bull beef production on intake, growth rate and feed conversion

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