High Feeding Level Research Articles

Influence of prepubertal feeding level on milk yield potential of dairy heifers: a review.

In replacement heifers, high levels of feeding resulting in high growth rates in the prepubertal period can cause severe reduction of the milk production potential. This has been demonstrated in many experiments; however, there are a number of experiments where this effect is not seen. In many cases, the reason for the lack of effect seems fairly obvious (short treatment periods, high pretreatment growth rates, small growth rate differences between treatment groups, variation of growth rates within treatment groups, treatment periods outside the critical period, etc.). However, in a few experiments absence of treatment effect cannot be explained in this way. This demonstrates that our knowledge on the effect of nutrition during rearing on the future milk yield of heifers is incomplete and that it may be possible to develop high growth rate feeding regimens for heifers. Experimental evidence suggests that the observed negative effects of feeding level on subsequent milk are due to impaired mammary development. Development of suitable high growth rate feeding regimens therefore requires understanding of the influence of nutrition on the physiological regulation of mammary development. Available data suggest that the growth hormone-insulin-like growth factor I axis is involved, but it is not clear how. It is likely that understanding of the role of insulin-like growth factor binding proteins is important. Alternative hypotheses involve possible effects of growth factors and modifications of mammary tissue sensitivity to hormones and growth factors.

Feeding behaviour of growing pigs using single or multi-space feeders

Most studies of the feeding behaviour of group housed growing pigs have used computerized single-space feeders, which result in a pig:trough ratio which differs from that found on commercial pig farms, where multi-space feeding troughs are used. The present experiment compared the feeding patterns of group housed, growing pigs given access to either a computerized single-space feeder or a four-space feeding trough. Eighty cross-bred entire male pigs (initial live-weight 32.3 ± 0.62 kg; mean ± s.e.) were allocated to groups of ten, and each group given access to one of the two feeder types. The feeding behaviour was measured automatically fro the single-space feeders, and determined for the four-space trough treatment from video tapes, where feeder visits were counted and timed, combined with daily weights of the food eaten per group. Pigs given access to a four-space trough visited the feeder much more frequently (84.5 vs. 14.3 visits day −1; s.e.d. = 5.3; P < 0.001), and for shorter durations (0.67 vs. 4.67 min per visit; s.e.d. = 0.36; P < 0.001), eating only a little per visit (24 vs. 149 g per visit; s.e.d. = 14; P < 0.001) compared with pigs kept in the groups given access to a computerized single-space feeder. High levels of allelomimetic feeding were shown by pigs using the four-space trough, with 61% of all visits initiated whilst one or more pigs were already feeding. Also, a higher proportion of visits were made adjacent to a feeding pig than would have been expected by change (0.59 vs. 0.50; P < 0.001). No significant differences were found between treatment in the rate of feeding or daily feeder occupation. The differences in feeding pattern did not result in differences in production variables in terms of daily feed intake, daily live-weight gain, and feed conversion ratio. A bout analysis was applied to the data using frequency distributions of length of intervals between visits. For pigs using the four-space trough visits could justifiably be collapsed into feeding bouts, whereas this was not the case for visits displayed by pigs using the single-space feeder. Pigs using the four-space trough showed a high frequency (0.64) of changes between spaces within each feeding bout. This may represent exploratory or sampling behaviour, which may aid the pig in obtaining a nutrient-sufficient diet should many different food items be available. Comparing feeding bouts from the four-space feeders to visits from the single-space feeders revealed no differences between the two types of feeders, indicating that single-space feeders constrain the feeding pattern mainly in terms of preventing changes between trough-spaces within bursts of feeding.

Nutrition and reproduction

Through their influence on embryonic and early fetal development dietary nutrients affect the size, vigour and viability of the newborn and, in the case of sheep, adult ovulation rates. Nutritional regimens that impair post-natal growth reduce ovarian follicular development and delay puberty but have little, if any, effect on either N-methyl-D-aspartate stimulated GnRH release or the pituitary content of gonadotrophins. Nutritional effects on ovulation rate in ewes are not always accompanied by shifts in circulating FSH concentrations. Instead they may operate through altered ovarian hormone feedback mechanisms that influence the duration of exposure of the gonadotrophin-dependent follicles to FSH or through threshold-reducing actions of specific nutrients and dietary-induced metabolites on the amount of FSH needed to support the gonadotrophin-dependent follicles. Recent results suggest that the enhanced faecal excretion of oestradiol by well-fed ewes may increase ovulation rate by reducing ovarian oestradiol feedback. In the post-partum period, the key hypothalamic and pituitary secretions for successful ovulation develop normally despite undernutrition but ovulation is prevented by failure of GnRH release with, in the case of suckler beef cows, a delay in oestrus arising from the repeated development and atresia of dominant ovarian follicles. This effect is accentuated in cows that are in poor body condition at calving. Alleviating the energy deficits of high-yielding dairy cows in early lactation by giving supplements of dietary fat can reduce the interval to first oestrus but subsequent fertility can be impaired. Loss of body protein delays oestrous cyclicity; paradoxically attempts to correct this loss in ruminants by feeding diets high in rumen undegradable protein can stimulate body fat mobilization and milk production with detrimental effects on rebreeding. Excess rumen degradable protein and high feeding levels reduce embryo survival, the latter by suppressing circulating progesterone concentrations. In superovulated ewes diet-induced reductions in progesterone concentrations during oocyte maturation can impart a legacy of developmental retardation leading to decreased embryo survival. In late pregnancy, undernutrition decreases uterine blood flow, fetal insulin and IGF-1 concentrations and impairs growth and development. In the newborn, low insulin and a low selenium and iodine status inhibit thermogenesis from brown adipose tissue. Insulin may also be important in conveying information on nutritional status to the GnRH neurones thereby initiating the cascade of events that is required for successful reproduction in both sexes.

Plasma concentrations of hormones and metabolic substrates in growing pigs after bovine growth hormone injections under various nutritional conditions.

The effects of GH injections on the concentrations of plasma hormones and metabolic substrates in pigs were studied under various nutritional conditions. In experiment 1, four pigs (Large white, barrows, 108 days old) were maintained at three feeding levels: (1) high level (8,501 +/- 46 kcal/ day), (2) maintenance level (2,104 +/- 44 kcal/day), and (3) fasting (last meal was on day -2). The bovine GH (100 micrograms/kg BW) was subcutaneously injected on experiment days 0, 1, and 2. In experiment 2, four pigs (Landrase, barrows, 120 days old) were maintained at the high feeding level and the bovine GH (100 micrograms/kg BW) was injected 2, 26, and 50 h after the last meal. The plasma hormone and metabolic substrate concentrations were measured. In experiment 1, the plasma IGF-I concentrations increased on days 1-4 in the high feeding level and maintenance fed pigs, but did not increase in the fasting pigs. The plasma glucose concentrations increased after the GH injection in the high feeding level and maintenance fed animals. The plasma NEFA concentrations increased after the GH injection in the maintenance fed and fasting animals. In experiment 2, the plasma IGF-I gradually decreased after the last meal. The GH injection administered 26 or 50 h after the last meal still produced an increase in the plasma IGF-I levels. These data clearly show that the effect of GH was modified depending on the nutritional condition of the pigs.

The Effects of Feeding Level and Nitrogen Source of the Diet on Mammary Development and Plasma Hormone Concentrations of Pre-pubertal Heifers

Abstract The effect of feeding level and nitrogen source on mammary development and plasma hormone levels of pre-pubertal (86 to 220 kg) Finnish Ayrshire heifers was studied. The treatments were: (1) LU, low feeding level + urea; (2) LR, low feeding level + rapeseed meal; (3) HU, high feeding level + urea; (4) HR, high feeding level + rapeseed meal. The average daily gains of the heifers on LU, LR, HU and HR diets were 692, 655, 805 and 890 g, respectively. There was a significantly higher amount of mammary parenchymal tissue and parenchymal DNA at low (L) compared with high (H) feeding levels, but no difference in mammary weights between nitrogen sources was found. Plasma insulin concentration was greater at H compared with L feeding levels, but plasma growth hormone (GH), insulin-like growth factor-I (IGF-I) and prolactin concentrations were not significantly affected by the feeding level. The amount of mammary parenchymal tissue did not correlate with the mean plasma concentration of prolactin and insulin. Also, no significant correlation between plasma GH (r = 0.32; P < 0.15) or IGF-I (r = 0.37; P < 0.09) and mammary growth was found. However, when GH measurements around feeding (2 h) were excluded, mammary development was positively correlated to plasma GH (r = 0.44; P < 0.05).

Influence of feed supply, temperature and body size on the growth of goldfish Carassius auratus larvae

The effects of feeding level, temperature and initial body size of goldfish larvae on survival, growth and food utilization were investigated using a mixed diet of Artemia nauplii and dry feed. Larvae of initial mean body weights 1.15 and 20.5 mg, respectively, corresponding to newly-hatched larvae (end of yolk sac resorption period) and 10 day old larvae, were fed with a 1:1 and 1:3 mixture of live Anemia and dry feed, respectively. Temperature (within the range of 20–28 °C) and body size influenced growth performance with the highest specific growth rates being obtained at 28 °C. Maintenance, optimum and maximum feeding levels were estimated at each temperature and body size. Best feed utilization (assessed as feed: gain ratio, protein efficiency ratio and apparent net protein utilization) was obtained at the maximum feeding levels in newly-hatched larvae (35, 50 and 70% of initial body weight, respectively at 20, 24 and 28 °C) whereas feed utilization decreased at the higher feeding levels in 10 day old fish.

Pond farming of Nile tilapia, Oreochromis niloticus (L.) in northern Cameroon. Comparing two different strategles for feeding cottonseed cake in tilapia male monosex culture

Two cottonseed cake feeding strategies were tested in pond culture of hand-sexed male Nile tilapia, Oreochromis niloticus (L.). (W0 > 80 g), with the objective of making better use of the algal blooms which develop when cottonseed cake is applied to a pond. In the conventional ‘progressive feeding strategy’, the daily amount of cottonseed cake was adjusted monthly for the total tilapia bioweight estimated from sampling, assuming that cottonseed cake primarily acted as a tilapia feed. In the ‘linear feeding strategy’, ponds received a fixed daily amount of cottonseed cake throughout the trial, based on the hypothesis that tilapia would cover their nutritional requirements mostly by grazing the algae. Each feeding strategy was tested at two feeding levels. Mean daily feeding rate R in the progressive feeding strategy averaged 48.6 (low feeding level) and 102.5 kg ha−1 day−1 (high feeding level), and 49.8 and 82.9 kg ha−1 day−1 in the linear feeding strategy. Significantly better growth rates and feed conversion rates were obtained in the progressive feeding strategy. Average extrapolated net pond production was highest at Rpr=6% body weight day−1 (10.61 ha−1, year−1). It was concluded that cottonseed cake contributed to tilapia growth mainly directly as a tilapia feed rather than indirectly as a pond fertilizer via algal production. Finally, the appropriateness of the metabolic feeding rate Rmb(BW0.8 day−1) was discussed, compared with the progressive feeding rate Rpr (%BW day−1). (BW denotes body weight). A practical, two-step linear feeding method was proposed for cottonseed cake as a ‘rule of thumb’ that is workable in the field.

The digestion of dry matter and non-starch polysaccharides from diets containing plain sugar-beet pulp or wheat straw by pregnant sows

AbstractForty days after mating, 16 pregnant sows were randomly allocated to two diets containing either sugar-beet pulp (SBP) or wheat straw (WS) each offered at two levels (1·0 or 1·5 × maintenance energy requirement (M), where M = 460 kJ digestible energy (DE) per kg0·75 per day). Diets were iso-nitrogenous, and contained similar levels of DE together with 260 g non-starch polysaccharides (NSP) per kg dry matter (DM) largely derived from either the SBP or the WS. A 7-day NSP and DM balance was made between day 60 and 100 of gestation. During lactation sows had ad libitum access to a conventional sow diet which contained neither SBP or WS.Outputs of both fresh and dry faeces from sows given diet WS were significantly greater than the outputs from sows given the corresponding SBP diets (P &lt;0·05), and outputs were significantly greater at the higher feeding level for both diets (P &lt; 0·05). There was a tendency for higher urinary outputs from sows given diet WS, but these were variable and not significantly different from those from sows given diet SBP. The apparent digestibility and retention of DM was significantly greater for the SBP diet than for diet WS but were not significantly affected by feeding level. The apparent digestibilities of the total NSP and each of the individual constituent monomers were significantly higher for diet SBP than for diet WS (P &lt; 0·001), but were independent of feeding level (P&gt; 0·05). Xylose was the most poorly digested NSP constituent from both diets. Apparent digestibility coefficients for the remaining NSP constituents in diet SBP were &gt; 0·8 and were &gt; 0·52 in diet WS, with the uronic acids and mannose being the most highly digested NSP fractions from diets SBP and WS respectively.

Alteration of heat production in young calves in relation to posture.

The effects of feeding level and ambient temperature on time-related alterations of heat production in relation to physical activity (posture) were studied in young calves after transportation. Twenty-four 6-d-old Holstein-Friesian male calves were assigned in a 2 x 2 factorial design to one of two feeding levels (high or low) and one of two ambient temperatures (7.5 degrees C or 19 degrees C). Heat production was measured per calf continuously every 9 min by indirect calorimetry for a 2-wk period. Calf's posture during these 9-min periods was measured with a photoelectric cell. After arrival, heat production of calves decreased with time (days). The amount of decline in heat production depended on feeding level and ambient temperature. This decline with time was largest at the low feeding level at 19 degrees C. Six to 12 d after arrival, heat production reached steady-state levels. A steady-state level of heat production was reached first at the high feeding level at 19 degrees C. Averaged over treatments, heat production during standing was 132 kJ.kg-.75.d-1 higher than during lying. Time spent standing by calves increased over time. This indicated that alteration in time spent standing did not account for the time-related changes in heat production. On the contrary, physical activity (posture) partly masked the alterations in metabolic rate of calves after arrival. However, differences in physical activity (posture) accounted for differences in both time to reach steady-state levels and linear decline in heat production over time between treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Level and Distribution of Concentrate in Late Pregnancy on Ewe and Lamb Performance

Abstract During two different years, 1986 and 1989, 129 and 102 ewes, respectively, were used to compare the effects of level and feeding pattern of concentrate during the last eight weeks of pregnancy. The ewes were given hay to cover maintenance, with supplemental feeding for pregnancy based on different amounts of concentrate. The control groups were fed according to Swedish recommendations, totalling 20 kg of concentrate, maximum level 0.4 kg per ewe and day (20:0.4) in a two-level pattern. The experimental groups were fed 20:0.7, 24:07 or 30:1.0 with a gradually rising feeding pattern. The treatments had a significant effect on changes in the live weight of ewes during late pregnancy and early lactation, with ewes on higher feeding levels losing less weight during pregnancy and gaining less weight on pasture. Over the whole production year, the changes during different production periods levelled out the total effect. Late pregnancy feeding also had a significant effect on lamb growth, with lambs fro...

Dietary-induced suppression of pre-ovulatory progesterone concentrations in superovulated ewes impairs the subsequent in vivo and in vitro development of their ova

In the first of three experiments, eight ovariectomised Greyface ewes primed with exogenous progesterone were used to provide quantitative data on the effects of two contrasting feeding levels (0.3 vs. 1.4 × maintenance) on plasma progesterone concentrations. Over the 9 day study period, mean (± SEM) daily progesterone concentrations were 4.3 ± 0.13 and 3.3 ± 0.17 μg l −1 for the low and high feeding regimens, respectively ( P = 0.06), indicating that high feed intake suppressed circulating progesterone levels. The second experiment examined the effect in superovulated Finn-Dorset ewes of a diet supplying either 0.6 (Group L, n = 8) or 2.3 (Group H, n = 8) times their daily energy needs for maintenance, from 1 day before introduction of exogenous progesterone to the time of insemination, on plasma progesterone concentrations and the viability of ova recovered 4 days after insemination. Mean (± SEM) plasma progesterone concentrations were 4.5 ± 0.17 μg l −1 and 2.8 ± 0.16 μg l −1 for L and H ewes, respectively, during the 12 day priming period ( P < 0.001). Eight hours after progesterone withdrawal, levels had fallen to 0.9 ± 0.06 μg l −1 and 0.8 ± 0.07 μg l −1 , respectively, then rose to 17.8 ± 3.01 μg l −1 and 12.9 ± 2.50 μg l −1 ( P > 0.10) at ovum collection. Intervals (mean ± SEM) to oestrous onset (14.5 ± 0.38 h) and the luteinising hormone (LH) surge (27.1 ± 0.98 h) were unaffected by feed intake. Mean (± SEM) ovulation rates (8.1 ± 1.57 vs. 7.8 ± 1.10) and numbers of ova recovered (5.0 ± 1.39 vs. 4.8 ± 1.11) were also similar for each group. However, the proportions of ova considered viable (over 32 cells) at recovery were 0.53 and 0.22 for L and H groups, respectively ( P < 0.005). Following 72 h culture (Tissue Culture Medium-199 (M199) + 10% foetal calf serum (FCS)), 0.55 and 0.27, respectively, had developed to blastocysts ( P < 0.025). Of ova assessed as viable at recovery, similar proportions (0.86 vs. 0.75) from L and H treatments developed to blastocysts, with corresponding nuclei counts (mean ± SEM) of 55 ± 5.2 and 55 ± 13.2. The third experiment used 12 superovulated Greyface ewes, each offered a different feed level within the range 0.6–2.5 × maintenance, to determine the nature of the relationship between feeding level, pre-ovulatory progesterone concentrations and ovum development at Day 2 following insemination and subsequently during 7 day co-culture (M199 + FCS). Increases in feeding level were accompanied by linear decreases in plasma progesterone ( r 2 = 0.79, P < 0.001), the interval to oestrous onset ( r 2 = 0.52, P < 0.01) and timing of the LH surge ( r 2 = 0.32, P < 0.06). Although undetectable at ovum collection, and somewhat equivocal after 4 day culture, high feeding levels prior to ovulation reduced the proportion of ova (0.16 vs. 0.58) developing to or beyond the expanding blastocyst stage after 7 day culture. Quantitative indices of cell division and protein synthesis confirmed this. In conclusion, excessive feeding during follicular recruitment and oocyte maturation in superovulated ewes imparts a legacy of embryonic loss and developmental retardation.

Growth and feeding of white steenbras, Lithognathus lithognathus (Cuvier) (Sparidae), under experimental culture conditions

Growth and feeding of white steenbras, Lithognathus lithognathus (Cuvier). under culture conditions was determined to assess its suitability for mariculture. Ration size ranged from 4.50% to 11.52% and from 1.67% 4.00% dry body weight for small (28 ± 2 g) and large (250 ± 23 g) fish, respectively. Condition factor (K) ranged from 1.19 to 1.35 and from 2.00 to 2.19 for small and large fish, respectively. Specific growth rate (SGR) at 16°C was 0.60% day−1 for 28-g fish, 0.29% day−1 for a 74-g fish, and 0.19% day−1 for a 250-g fish. Gross conversion efficiency (GCE) was inefficient at high feeding levels (21.3%) compared with low feeding levels (32.6%). Proximate body composition in terms of moisture, protein. lipid, ash and energy were not significantly affected by feeding regime or temperature (P > 0.05). The experiments indicate that feeding regimes should be maintained at relatively low levels to obtain optimum K, GCE and SGR, and to avoid over-feeding and food wastage. It was concluded that L. lithognathus could be a suitable candidate for mariculture.

Effects of dietary protein/energy ratio, ration size, dietary energy source and water temperature on nitrogen excretion in rainbow trout

Postprandial nitrogen excretion was measured on groups of rainbow trout of mean body weight (MBW) 35g, fed, from maintenance to near satiation, diets containing graded levels of digestible energy (14 to 20 kJ/g dry matter) with digestible protein (DP)/digestible energy (DE) ratios of 18 and 23 mg/kJ at each protein level (DP: 32.5 or 37% dry matter). Irrespective of the diet and the ration size, urea-N excretion amounted to 15-16% of ammonia-N excretion. The higher the dietary DP/DE ratio, the greater was the amount of ammonia excreted. At high ration levels (1.5% and 2% of MBW/d), N excretion was 39-40% of digestible N intake for diets with a DP/DE ratio of 18 mg/kJ and 44% of digestible N intake for diets with a DP/DE ratio of 23 mg/kJ irrespective of the dietary protein level. At lower ration levels, N excretion as percent of N intake was higher than at higher feeding levels. Another experiment was performed to compare the effect of dietary lipid and digestible carbohydrate on ammonia excretion in rainbow trout reared at two water temperatures (8°C and 18°C). Neither water temperature nor dietary sources of non-protein energy had any significant effect on N excretion expressed as proportion of digestible N intake.

The role of the large intestine in post-ruminal digestion of feeds as measured by the mobile-bag method in cattle.

To study the importance of site of recovery and other factors related to mobile-bag (MB) digestion values, two consecutive experiments in which diets were applied in a 3 x 3 Latin square design, were carried out with cannulated growing heifers. In Expt 1, several types of experimental feed were exposed to intestinal digestion in mobile bags made of two cloth types and filled with intact or rumen-undegradable (RUD) feed material to be recovered either from the ileum (IB) or faeces (FB). In Expt 2, mean retention time (MRT) of Yb-labelled digesta particles within the intestine and in vivo digestibility of diets were measured. With vegetable concentrates, FB resulted generally in slight overestimation of small-intestinal dry matter and N digestion, while with meat-and-bone meal no difference between FB and IB was found. The respective N digestibility of RUD late-cut silage was clearly underestimated as measured from FB. The disappearance of neutral-detergent fibre (NDF) of all feeds under test was higher from FB than from IB. It was not possible to isolate the influence of the large intestine on the MB values by changing bag cloth type. Irrespective of the longer retention time of bags and longer MRT of Yb in the intestine on a low as compared with a high level of feeding, only NDF disappearance of feeds increased due to lower feeding level. Altering the diet type to increase large-intestinal fermentation, as indicated in vivo, usually had no effect on the MB values. It is concluded that the site of collection of bags does not practically affect small-intestinal digestion values of feed N, unless the feed is rich in fibre.

Physiological effects of exercise in male and female Saanen goats at the same body weight but different feed intake

Effects of treadmill exercise in males were 25% higher respiration rates (RR) in comparison to females ( P < 0.05). After 1 h exercise RR increased around 6-fold ( P < 0.001). With feed, RR increased gradually ( P < 0.001); comparisons were 1.0:1.3:3.9 with low (400 g), medium (600 g) and high (1200 g) feed intake, respectively. Rectal temperature (RT) showed differences between sexes ( P < 0.1) but males were less tolerant (0.2 °C higher) than females. At different levels of feed, RT increased gradually by 0.2 and 0.4 °C at medium and high levels, respectively, compared to low feeding ( P < 0.001). Rump skin temperature (RST) showed difference between sexes ( P < 0.1); the male was 0.2 °C higher than female. Loin skin temperature (LST) differed between feeds ( P < 0.001), increasing gradually by 0.5 and 0.9 °C at both medium and high feeding level compared to low. Ear skin temperatures (EST) in males were 0.6 °C lower than females. It is concluded that an increase in level of feed intake experienced by the goat during exercise was followed by significant increases in the RR, RT, RST and LST.

The effect of increasing starch intake and source in supplements fed in a complete diet to dairy cows on total dry matter intake, milk yield and milk composition, and fatty acid content of milk fat when supplements were fed in complete diets or three times a day

Dietary starch can increase milk protein and reduce milk fat content, but when fed in single meals may cause problems with rumen stability. To overcome the risk of acidosis, complete diet feeding or reducing the rate of starch degradation (by feeding sodium hydoxide treated whole wheat rather than ground wheat) may provide solutions. In addition, there is evidence to suggest that feeding high levels of cereals alters fatty acid composition of body fat (Garton et al 1972), and similar changes may occur in milk fat.Ninety six multiparous Holstein cows were fed grass silage to appetite and supplements designed to provide increasing amounts of wheat starch either as wheat ground to pass through a 3 mm screen (GW) or as sodium hydroxide treated whole wheat (STW), prepared by adding 30 kg sodium hydroxide per tonne of wheat plus water to bring the total dry matter to 700 g/kg, and stored for 5 days before feeding.

The effect of increasing starch intake and source in supplements fed in a complete diet to dairy cows on total dry matter intake, milk yield and milk composition, and fatty acid content of milk fat when supplements were fed in complete diets or three times a day

Dietary starch can increase milk protein and reduce milk fat content, but when fed in single meals may cause problems with rumen stability. To overcome the risk of acidosis, complete diet feeding or reducing the rate of starch degradation (by feeding sodium hydoxide treated whole wheat rather than ground wheat) may provide solutions. In addition, there is evidence to suggest that feeding high levels of cereals alters fatty acid composition of body fat (Garton et al 1972), and similar changes may occur in milk fat.Ninety six multiparous Holstein cows were fed grass silage to appetite and supplements designed to provide increasing amounts of wheat starch either as wheat ground to pass through a 3 mm screen (GW) or as sodium hydroxide treated whole wheat (STW), prepared by adding 30 kg sodium hydroxide per tonne of wheat plus water to bring the total dry matter to 700 g/kg, and stored for 5 days before feeding.

Effects of winter feeding level on the performance of red deer calves (Cervus elaphus)

The aim of this trial was to determine the effects of a high winter feeding level on the performance of red deer calves from weaning to 15 months of age.Two groups of 10 calves in each group were fed indoors from weaning to turn-out on good quality hay ad libitum. They received concentrates for 197 days, the first group (treatment H) ad libitum, and the second (treatment L) a daily quantity of 616 g dry matter (DM). At turn-out the two lots were grouped together for 149 days on natural pastures containing grass species characteristic of the area.During the indoor period, treatment H calves consumed 2·5 times more concentrate than those in treatment L (272v.110 kg DM) and 2·8 times less hay (48v.234 kg DM). They weighed 19·6 kg more at turn-out (88·9v.69·3 kg). The difference in weight decreased to 8·8 kg at 15 months of age, but varied according to sex. This reduction of the weight gap between groups was due to the better adaptation of treatment L to pasture and to compensatory growth resulting from a higher grass intake after turn-out.It is concluded that despite the good performance of treatment H animals in winter, a high energy level of feeding is only advantageous in certain cases. It is of benefit to animals that are to be slaughtered at 1 year of age and to lateborn calves, and can improve the frame development of females in their first breeding season.

Influence of increased vitamin levels for the first 35 d postweaning on breeding and subsequent lactation performance of sows (1995)

Four hundred and eight sows were used to evaluate the effects of feeding high levels of vitamins (2 to 7 times average inclusion rate) for the first 35 d postbreeding on later reproduction performance. number of pigs born alive and number born dead following feeding high vitamin levels showed a numeric advantage compared with sows fed the control diet. These numeric responses resulted in trends toward higher number weaned (9.75 vs 9.54) and litter weaning weight (l 07.8 vs 105.4 lb). Further research needs to be conducted to determine which vitamin or vitamins may have an influence on embryo survival.; Swine Day, Manhattan, KS, November 16, 1995

Plasma protein for pigs weaned at 19 to 24 days of age: effect on performance and plasma insulin-like growth factor I, growth hormone, insulin, and glucose concentrations.

Three experiments were conducted to evaluate spray-dried porcine plasma (SDPP) protein in diets for early weaned pigs. In Exp. 1, 144 weanling pigs (24 +/- 4 d of age) were used to determine the effects of replacing dried skim milk (DSM) with either 4% SDPP or 2.75% spray-dried blood meal (SDBM) in Phase 1 diets (d 0 to 14 postweaning). During 0 to 14, pigs fed SDPP or SDBM had higher ADG (P < .05) and ADFI (P < .1) than those fed DSM. Pigs fed SDPP had greater (P < .05) ADG and ADFI (P < .1) than those fed SDBM. In Exp. 2, performance was similar in pigs fed two plasma protein sources (AP-820 and MP-722). In Exp.3, 18 weanling pigs (19 to 20 d of age) were used to determine the effects of feeding high levels of SDPP on performance and on plasma IGF-I, growth hormone, insulin, and glucose concentrations. Pigs were fed either a control diet containing 21.5% soybean meal (SBM) or a diet containing 14% SDPP. Treatments were applied for 14 d (Phase 1). During d 0 to 14, pigs fed a SDPP had a greater ADG and ADFI (P < .05) than pigs fed SBM. Replacing SBM with SDPP did not affect plasma IGF-I and glucose concentrations. However, SDPP replacement increased (P < .06) plasma growth hormone concentrations. Insulin levels were greater (P < .06) in pigs fed SBM than in those fed SDPP. These results indicate that SDPP and SDBM are effective alternatives to DSM or SBM in Phase 1 diets and the two plasma protein sources will produce similar performance. The factor(s) responsible for this improved performance does not seem to involve a change in plasma IGF-I.