Rate Of Live-weight Gain Research Articles

Effects of Substitution of the Imported Super Concentrate with Graded Levels of Marula (Sclerocarya birrea) Kernel Meal on Growth Performance and Meat Quality of Broiler Chicks

This study was conducted in Dilling town, South Kordofan State, Sudan with the objective of studying and evaluating the effects of using graded levels of Marula, Sclerocarya birrea, kernel meal on broilers Growth performance and meat quality. Two hundred, one day old (Ross 308) chicks were distributed into five groups of treatments where every 20 birds were housed in separate unit assigned to the five treatments A, B, C, D and E with four replicates, on floor covered with saw dust. The chicks were transferred periodically to ensure random housing. Starter and finisher rations were formulated for each treatment. The experimental diets were formulated with five levels of Sclerocarya birrea of (2.5%), (5%), (7.5%) and 10% as a substitute for the protein super concentrate. At the end of the experiment, twenty five chickens were slaughtered for carcass cuts yield and meat quality evaluation. The results indicated that feed intake was significantly (P<0.01) higher in birds on ration C compared to those on rations A, B, D and E. Similarly the live weight of chickens was significantly (P<0.01) heaviest in group C than those of groups A, B,D and E. Dressing percentage, carcass weight and weight of cuts were also significantly (P<0.01) higher for birds on ration C and lowest weight was recorded for those on ration E. Also the abdominal fat weight was higher for groups D and E with significantly differences (P<0.01) when compared with groups A, B and C. It was the lowest for chickens fed ration C. The percentage of fat in the body was higher in meat samples obtained from birds on rations D and E and lower for those on rations A, B and C. The study concluded that feeding Sclerocarya birrea kernel meal to broiler chicks improved feed intake, the rate of live weight gain though it increased the proportion of body fat in carcass samples when the level increased above 5%. It was recommended further studies be conducted using lower levels of Sclerocarya birrea kernel cake after oil extraction since it is found abundantly, can be obtained at low cost and rich in essential amino acids and fatty acids as well.

USE OF FEED ADDITIVE TEP-MIX IN THE FEEDING OF REPAIR HEIFERS

In most of modern protein nutrition systems by determining the protein requirement of animals, it do not emanate from the content of crude and digestible protein in the ration, but from the amount of protein degraded in the small intestine and defined as the sum of degradable and non-degradable protein in the rumen. A new approach to providing protein nutrition to highly productive animals is based on providing the animal body with easily soluble nitrogen compounds of feed protein and non-protein sources of nitrogen, which is provided by proteolysis of microorganisms and feed protein. During growing calves, the inclusion of protein-energy feed additives with different content of protected protein in the composition of complete diets contributes to obtaining the planned indicators of growth intensity and development of young animals, reducing nutrient consumption and has a positive effect on the economics of growing. As a result of the scientific and economic experience, it has been proved that the inclusion of high-protein feed additives with different contents of degradable protein and starch makes it possible to balance the rations of calves with the necessary amount of nutrients, minerals and biologically active substances. The using of a feed additive with a high content of protein non-degradable in the rumen and passing starch in the diet of heifers of the experimental group made it possible to obtain higher rates of live weight gain of animals by 10,1-10,2 % when grown from 3 to 10 months of age with a highly probable difference. Compared with the control group, which indicates a high productive effect of this additive compared to sunflower meal. The implementation of perspective developed protein supplements in the rations of calves during growing helps to reduce the amount of feed consumed per group by 4314.2 UAH during the experiment period, and allows you to receive additional income from the commercial value of the gain of the whole group – UAH 8719 Keywords: heifers, supplement, feeding, live weight gain, protein.

The use of biochemical blood markers for early prediction of the intensity of live weight gain of calves

The aim of the research was to identify promising biochemical markers of blood associated with the intensity of live weight gain in young cattle. The work was carried out in 2021...2022 in the conditions of the dairy farm of LLC Severnaya Niva in the Kortkerossky district of the Komi Republic. A group of newborn heifers of the Kholmogorsky breed (n = 30) was selected for the experiment. It has been established that on the first day after birth, calves with intensive growth rates had lower AsAT activity (r = -0.510) and iron concentration (r = -0.650) in blood serum, and vice versa a higher level of SMLMM рlasma (0.626). At later stages of the analysis, a pronounced correlation of the intensity of body weight gain was observed with respect to the activity of alkaline phosphatase: -0.639 and -0.744 on day 7 and 14, respectively. It was determined that many of the calculated coefficients obtained during the blood test on the 14th day after birth had a more noticeable correlation with the intensity of growth. Such markers included: Alkaline phosphatase/Calcium (-0.746), Alkaline phosphatase/Magnesium (-0.756), Magnesium/Alkaline Phosphatase (-0.760), Calcium×Phosphorus/Alkaline Phosphatase (0.758) and Alkaline Phosphatase/(Calcium+Magnesium) (-0.753). At the next stage, the analysis of the rate of live weight gain in heifers ranked by the increase in the values of the developed coefficients was carried out. It is proved that the use of coefficients contributed to a more pronounced differentiation of the rate of weight gain in comparison with the values established with the use of one alkaline phosphatase. Thus, the calculated index of Alkaline phosphatase/Calcium/ Magnesium on the 1st, 7th and 14th days of postnatal ontogenesis provided a difference between the phenotypes of the 1st and 3rd groups by 74.1(P≤0.05), 92.6 (P≤0.01) and 90.7 (P≤0.001) g of weight gain per day, whereas the difference when using one alkaline phosphatase was 33.3; 16.0 and 12.2 % less. Thus, the use of these coefficients to predict the rate of live weight gain in calves can increase the accuracy of the selection of animals with the desired phenotype in early postnatal ontogenesis.

Growth rate and meat quality of guinea fowl kept in farm conditions

The research (2018-2019) was conducted in the conditions of a peasant farm in the Voronezh region. The paper evaluates the indicators of the growth rate and meat productivity of the preserved gene pool groups of guinea fowl. The experiment involved three groups of daily guinea fowl of 200 heads of different genetic origin: lines of the Volga white breed (the original VB-4, selected by the rate of live weight gain and reproductive characteristics; autosex VBA-1, selected by the color of down, feather and productive characteristics) and gray-speckled guinea fowl of unknown origin. Studies have shown that the live weight of guinea fowl of the VBA-1 line exceeded the live weight of poultry from other groups of guinea fowl, a significant excess was noted at 8, 12 and 13 weeks of age. The greatest coefficient of variation of the trait was observed at 8 weeks of age. The analysis of relative gain in live weight of guinea fowl showed that up to 10 weeks of age, the highest relative growth rate of guinea fowl of all experimental groups was observed (14.0-17.0 %). Starting from the age of 11 weeks, this indicator gradually decreased (4.3-13.4 %). It was found out that under the same conditions of keeping and feeding, the feed costs per 1 kg of live weight gain in guinea fowls of the VBA-1 line were less by 0.09-0.16 kg (3.11-6.33 %) compared to poultry of the VB-4 line and by 0.2-0.4 kg (5.49-12.82 %) compared to their gray-speckled peers. The results of anatomical cutting of guinea fowl carcasses showed that the experimental groups of poultry significantly (P< 0.05) differed among themselves in the degree of development of internal organs and tissues. The yield of edible parts was 60.2-61.1 %, depending on the group of poultry. The large live weight noted by us in linear poultry is the reason for their better meat productivity, which is directly related to an increase in the absolute mass of the eviscerated carcass, its edible parts, muscles and bones. Based on the data obtained, the optimal age of poultry slaughter for meat was determined at 10-12 weeks of life.

Effects of feeding varying dietary crude protein and digestible energy concentrations on performance of pigs raised in a humid tropical environment

This paper aims at investigating relationships and effects of varying protein and energy levels on growth performance, efficiency of feed conversion and efficiency of nutrient utilization of weanling pigs fed from of 9 to 60kg. A total of one hundred and twenty weanling pigs weighing ± 9kg were allotted randomly to sixteen groups of eight pigs each. for females and four castrated males in a 4x 4factorial design. The sixteen diets consist of four digestible energy levels (3,000: 3300: 3,600 and 3,900 kcal/kg) and four crude protein levels (18; 21: 24 and 27%). The pigs were fed these experimental diets until they attained a predetermined liveweight of 60 +1.5 kg. The effects of the varying crude protein and digestible energy were studied on growth and performance parameters Neither protein nor energy levels significantly affected daily feed intake, but significantly decreased daily feed intake at 27protein level. Daily protein intake was influenced by protein intake and digestible energy intake was also significantly influenced by digestible energy intake. There were no significant interactions between protein and energy levels with respect to feed intake and intake of protein and energy Energy but no protein levels significantly influenced rate of live weight gain. Feed conversion efficiency (FEC) was highly (P 0.001) influenced by energy but not protein levels. In both sexes, females and castrated males, increasing dietary levels of protein and energy resulted in improved efficiency of feed utilization within protein levels but there were significant differences between the two highest energy levels for castrated males and within the diets with 3.300, 3.600 and 3.900 kcal/DE/kg for the females. When high protein levels were combined with high energy levels feed intakes were depressed only on the 279% protein level. Feed conversion efficiency was maximized on the diet with 21 and 249% protein levels with appreciable sex diferences, with female pigs requiring more protein than males. Digestible Energy range of 3,300 and 3,600 kcalkg would be adequate for maximum gain and efficiency of feed utilization in pigs under the humid tropical environment tropical. Feed to gain ratio, a very important economic index should be an important index of the quality of any diet for promoting growth.

Growth pattern to the end of the mating period influences the reproductive performance of merino ewe lambs mated at 7 to 8 months of age

The reproductive performance of Merino ewe lambs is highly variable and generally poor in comparison to older ewes. In this study, we determined the impacts of growth pattern to the end of the mating period and sire genetics on the reproductive performance of Merino ewe lambs. Five hundred ewe lambs with full pedigree records were managed under commercial conditions from weaning and weighed 43.5 kg at the start of the mating period with an average age of 224 days. The ewe lambs were offered a moderate or high feed allowance to achieve target growth rates of 100 or 200 g/day during a 46-day mating period. They were then recombined and scanned for pregnancy status 60 days after the mating period. At the individual animal level, a 5 kg greater live weight at the start of the mating period increased reproductive rate (foetuses per 100 ewes joined) by about 20% (P < 0.001). Regardless of their live weight at the start of the mating period, gaining an extra 100 g/day of live weight during the mating period further increased their reproductive rate by about 20% (P < 0.001). Ewe lambs from sires with higher Australian Sheep Breeding Values for fat measured post-weaning achieved a higher fertility (P < 0.05) and reproductive rate (P < 0.01) regardless of feed allowance treatment. The effects of sire fatness was significant even when the sire breeding values for live weight measured post-weaning were included in the model. The effects of managing growth pattern and sire genetics were additive, so improving the reproductive performance of Merino ewe lambs mated at 7 to 8 months of age requires improving their feed allowance and rate of live weight gain until the end of the mating period and using sires with higher breeding values for fatness.

Effects of High Ambient Temperature and Bypass Protein Supplementation on Performance of Crossbred Lambs

The objective of this experiment was to study the effect of dietary supplementation with a source ofbypass protein (cottonseed meal, CSM) on the performance of growing crossbred wethers fed lowdigestibility roughage at high ambient temperature. Sixteen unshorn Border Leicester x Merino lambsaged 6 months and weighing 24.90.37 kg were allocated into a 2x2 factorial design (2 diets and 2ambient temperatures). Each group was fed either wheaten chaff + 2% urea ad libitum or wheaten chaff +1% urea ad libitum + 100g/d cottonseed meal. The results show that respiration rate and rectal temperaturewere significantly affected by ambient temperature (P&lt;0.01), but not by diet. Total dry matter intake wassignificantly higher (P&lt;0.01) at lower temperature than at high temperature, and significantly higher(P=0.04) on the supplemented diet than on the control diet. Water intake tended (P=0.06) to be higher onthe CSM+ diet than on the control diet, and was significantly at greater (P&lt;0.01) high ambient temperaturethan at low temperature. The concentration of NH3-N in the rumen fluid (ranged from 310±17 to 413±20mg N/L) did not differ significantly either between diets or ambient temperatures. Blood plasma ureanitrogen concentration was significantly higher in sheep on the control diet than in those on thesupplemented diet, and at low than high temperature. The organic matter digestibility was not significantlyaffected by temperature and diet. The rate of live weight gain was significantly (P&lt;0.01) reduced by highambient temperature and the interaction between diet and temperature was significant (P&lt;0.01). At lowtemperature, lambs on the supplemented diet grew significantly faster than those on the control diet, butnot at high temperature. In conclusion, high ambient temperature increases respiration rate, rectaltemperature and water intake but reduces dry matter intake and live weight gain. Supplementation with100 g/d of cottonseed meal could not outweigh the depressing effects of constant high ambienttemperature and humidity imposed in this experiment.

Influence of climate variability and stocking strategies on greenhouse gas emissions (GHGE), production and profit of a northern Queensland beef cattle herd

Previous studies of greenhouse gas emissions (GHGE) from beef production systems in northern Australia have been based on models of ‘steady-state’ herd structures that do not take into account the considerable inter-annual variation in liveweight gain, reproduction and mortality rates that occurs due to seasonal conditions. Nor do they consider the implications of flexible stocking strategies designed to adapt these production systems to the highly variable climate. The aim of the present study was to quantify the variation in total GHGE (t CO2e) and GHGE intensity (t CO2e/t liveweight sold) for the beef industry in northern Australia when variability in these factors was considered. A combined GRASP–Enterprise modelling platform was used to simulate a breeding–finishing beef cattle property in the Burdekin River region of northern Queensland, using historical climate data from 1982–2011. GHGE was calculated using the method of Australian National Greenhouse Gas Inventory. Five different stocking-rate strategies were simulated with fixed stocking strategies at moderate and high rates, and three flexible stocking strategies where the stocking rate was adjusted annually by up to 5%, 10% or 20%, according to pasture available at the end of the growing season. Variation in total annual GHGE was lowest in the ‘fixed moderate’ (~9.5 ha/adult equivalent (AE)) stocking strategy, ranging from 3799 to 4471 t CO2e, and highest in the ‘fixed high’ strategy (~5.9 ha/AE), which ranged from 3771 to 7636 t CO2e. The ‘fixed moderate’ strategy had the least variation in GHGE intensity (15.7–19.4 t CO2e/t liveweight sold), while the ‘flexible 20’ strategy (up to 20% annual change in AE) had the largest range (10.5–40.8 t CO2e/t liveweight sold). Across the five stocking strategies, the ‘fixed moderate’ stocking-rate strategy had the highest simulated perennial grass percentage and pasture growth, highest average rate of liveweight gain (121 kg/steer), highest average branding percentage (74%) and lowest average breeding-cow mortality rate (3.9%), resulting in the lowest average GHGE intensity (16.9 t CO2e/t liveweight sold). The ‘fixed high’ stocking rate strategy (~5.9 ha/AE) performed the poorest in each of these measures, while the three flexible stocking strategies were intermediate. The ‘fixed moderate’ stocking strategy also yielded the highest average gross margin per AE carried and per hectare. These results highlight the importance of considering the influence of climate variability on stocking-rate management strategies and herd performance when estimating GHGE. The results also support a body of previous work that has recommended the adoption of moderate stocking strategies to enhance the profitability and ecological stability of beef production systems in northern Australia.

Relationships among Puberty, Muscle and Fat, and Liveweight Gain during Mating in Young Female Sheep.

Greater depths of muscle are associated with better reproductive performance in ewe lambs, but, in adult ewes, reproductive performance also seems to vary with liveweight gain during the mating period. Therefore, in a large field study with Merino ewe lambs, we tested whether the relationships among eye muscle depth (EMD), fat depth (FAT) and reproductive performance depend on liveweight gain during the mating period. We selected lambs with a wide range in phenotypic values for depths of eye muscle (EMD) and fat (FAT) and assigned them to dietary treatments designed to achieve low (LOW, n=244) or high (HIGH, n=237) rates of liveweight gain during a 28-day mating period. The LOW treatment maintained live weight, whereas the HIGH treatment gained 179±3.8g/day (p<0.001). From those ewe lambs that attained puberty, first oestrus was detected at live weight 37.8±0.2kg and age 232days. The proportion of ewes that attained puberty increased with EMD (p<0.01). Ewes from the HIGH treatment were more fertile (pregnant ewes per 100 ewes exposed to rams) and had a higher reproductive rate (foetuses in utero per 100 ewes exposed to rams; p<0.001) than those from the LOW treatment. Fertility and reproductive rate were positively correlated with weight gain during mating as well as live weight at the start of mating, FAT and EMD (p<0.05 to <0.001). We conclude that faster growth, due to either extra nutrition during mating or higher phenotypic potential for fat and muscle, will increase reproductive performance in ewe lambs mated at 8months of age.

Adaptation behaviour of local and rangeland cattle relocated to a temperate agricultural pasture

Relocating cattle from rangeland properties to agricultural pastures in southern Western Australia allows producers to improve year-round continuity of feed supply in their beef cattle businesses, and can reduce substantially the time taken to grow animals to meet market specifications. In this study the behaviour and growth of two groups of young cattle that were sourced from different locations was evaluated after they were transferred to a new extensive grazing system. In Experiment 1, 122 Limousin-cross heifers that were raised in the agricultural region of Western Australia (AR cattle) were transferred to the experimental site from a neighbouring property (~10 km away). In Experiment 2, 95 Brahman-cross heifers that were raised in the rangelands of Western Australia (RR cattle) were transferred to the experimental site. Animal growth and behaviour were analysed across time and differences in the time-course of behavioural changes between the groups were compared. Rate of liveweight gain in the AR cattle remained consistent (~1.2 kg/day) during the experiment. There was an increase in horizontal (16%; P &lt; 0.001) and vertical (12%; P = 0.002) head movement in AR cattle over the first several weeks after relocation, indicative of increased grazing activity, but there was little change in other behaviours over the duration of the experiment. In contrast, the RR cattle had reduced growth during the first 4 weeks after relocation (P &lt; 0.001). From weeks 2–4 weight gain in RR cattle was 0.31 kg/day, approximately one-quarter of their average daily gain attained 4 weeks later. During the first 6 weeks, RR cattle showed behavioural changes indicative of adaptation, including a 61% increase in horizontal head movements, suggesting more grazing activity. The paddock area utilised daily by RR cattle was 32% higher in week 6 compared with week 1, and during daylight hours (0600–1900 hours) they began to travel more (23%) and spent more time active (16%). We conclude that rangeland-raised Bos indicus heifers take from 4 to 6 weeks to adapt from their previous large paddocks/natural plant environment to a new temperate agricultural environment. Our results suggest that the cause of lost productivity in rangeland cattle when they are relocated to a temperate pasture is at least in part due to initial lower grazing activity as they become familiar with the new environment.

Effect of Slaughter Age on Fattening Performance and Carcass Characteristics of Japanese Quails (Coturnix coturnix japonica)

Seker, I., Bayraktar, M., Kul, S. and Ozmen, O. 2007. Effect of slaughter age on fattening performance and carcass characteristics of Japanese quails (Coturnix coturnix japonica.) J. Appl. Anim. Res., 31: 193–195. To determine the most economic slaughter age for male Japanese quails a total of 220 quail chicks were fed a standard feed up to 49 days. Rate of live weight gain started decreasing after 28 days of age. Feed consumption showed similar trend after d35. However, the feed required for each gram of weight gain exhibited steep increase after d42. Dressing percentage was the highest when the birds were slaughtered on d35. Considering these results the slaughter of male Japanese quails is recommended at 42 days of age.

Effect of forage/concentrate ratio and dietary coconut oil level on methane output and performance of finishing beef heifers

Intake, animal performance and methane (CH 4) output was investigated using 36 finishing Charolais cross heifers (mean starting weight 462 kg, S.D.±16) fed ad libitum over an 11-week period. Six dietary treatments were investigated in a randomised block design experiment with a factorial arrangement of treatments. The six experimental diets consisted of three forage/concentrate (F/C) ratios (0.65:0.35, 0.40:0.60 and 0.10:0.90) supplemented with two levels of coconut oil (0 or 350 g/day). Rumen protozoa numbers were significantly ( P<0.001) lower for diets containing coconut oil at the end of the trial. Reducing the F/C ratio resulted in significantly ( P<0.001) increased rates of live weight gain (LWG) and carcass gain (CG), but coconut oil had no effect on animal performance. Methane output in litres per day was significantly modified ( P<0.001) by both the F/C ratio and level of coconut oil. Maximal CH 4 output was recorded on the 0.40:0.60 diet, with coconut oil reducing daily CH 4 output regardless of the F/C ratio. Methane output per unit of animal product (per kg of LWG and carcass gain) was significantly reduced by lower F/C ratios and the dietary inclusion of coconut oil ( P<0.001 and P≤0.003, respectively). No significant ( P>0.05) interaction between the F/C ratio and coconut oil level was identified although coconut oil significantly reduced dry matter intake (DMI), CH 4 l/day and LWG on the 0.65:0.35 F/C ratio diet.

Effect of dietary protein concentration and source on the growth rate and on body composition of Holstein-Friesian male calves

AbstractHolstein-Friesian male calves, aged 160 to 450 days, and of live weight 180 to 530 kg, were used to determine the effects of dietary nitrogen level and dietary nitrogen source on performance. Experiment 1, tested dietary nitrogen level, and involved two trials with three dietary-nitrogen levels and equal dietary metabolizable energy (ME) 11·7 MJ/kg dry matter (DM). The crude protein (CP) level was reduced in the course of the trials by 40 g/kg, the experimental average CP in the diets being 146, 126 and 106 g/kg for the high (HP), medium (MP) and the low protein (LP) diets, respectively. The urea space (US) for estimation of body protein deposition and the rumen volume for calculation of empty body weight were measured in trial A of experiment 1. Experiment 2 involved four diets of equal ME concentrations; (11-7 MJ/kg DM), in three of which the CP contents were equal but from different sources: (a) 110 g/kg, all of it true protein (TP), negative control; (b) 130 g/kg, all of it TP; (с) 130 g/kg CP, 20 g/kg of it is poultry litter (PL) protein; (d) 130 g/kg CP, 40 g/kg of it is PL protein. Significantly lower US and ratio of US to live weight were found in the calves on the LP diet, from the age of 265 days than in the calves on the other diets. The ratio of US to live weight significantly decreased with increasing age in all protein level treatments. Until the age of 300 days the rumen volume was significantly higher on the LP diet than on the other diets. Calves on the HP diet had the highest daily gain and carcass gain. The recommendation to reduce the dietary protein as age increased to lower than 120 g/kg caused a reduction in the energy retained from the diet but protein deposition was not impaired. Protein deposition was impaired when the CP was reduced by 20 g/kg below the level recommended by the National Research Council. The inclusion of poultry litter in the diet, with ME concentration being maintained, did not reduce the rate of live-weight gain, and improved food conversion efficiency.

Bancos de proteína de leucena e de guandu para suplementação de ovinos mantidos em pastagens de capim-buffel

O experimento foi realizado com o objetivo de estudar, em ovinos mantidos em pastagens de capim-buffel, a utilização de leucena ou guandu, como bancos de proteína, durante estação seca. Foram testados nove tratamentos experimentais, constituídos pela combinação de três tipos de pastagens (capim-buffel, capim-buffel+guandu e capim-buffel+leucena), com três taxas de lotação (4, 6 e 10 borregos/ha). As pastagens, em duas repetições, foram estabelecidas em dezoito piquetes de 0,5 ha. Foram utilizados 60 borregos, com peso médio inicial de 19,4 kg, que receberam água e suplementação mineral completa à vontade e foram pesados a intervalos de 14 dias após 16 horas de jejum. Na pastagem de capim-buffel+leucena, foi possível elevar a lotação de quatro para seis borregos/ha, sem redução do ganho individual de peso dos animais, com conseqüente aumento da produção por unidade de área. Na pastagem de capim-buffel+guandu, não houve melhoria de desempenho dos animais em comparação à pastagem de capim-buffel. Concluiu-se que bancos de proteína de leucena podem melhorar a qualidade de pastagens de capim-buffel.

Growth performance and apparent nutrient digestibility in weaned piglets offered wheat-, barley- or sugar-beet pulp-based diets supplemented with food enzymes

AbstractPig studies on non-starch polysaccharides (NSPs) have mainly focused on finishing and breeding animals because their digestive capacity and ability to ferment fibre are considered greater than piglets. In this study, growth and nutrient digestibility, with particular reference to NSP constituent monomers, were evaluated in piglets offered contrasting sources of NSPs. The potential for enhancing growth performance and digestibility with exogenous food enzymes (xylanase, amylase, pectinase and beta-glucanase) was investigated. A total of 240 piglets weaned at 28 days of age, in groups of six, were allocated to six treatments in a 3×2 factorial design, diet type (W, B and SBP) by enzyme supplementation (–v. +). Diet W was wheat based and formulated to supply 14 MJ digestible energy (DE) per kg. In diets B and SBP, DE was reduced to 13·25 MJ/kg by replacing wheat with barley (708 g/kg) or with 185 g/kg dried unmolassed sugar beet pulp. Growth was monitored over 4 weeks. Digestibility of diets B–, B+, SBP– and SBP+ was evaluated in 16 piglets, in groups of four, using a 4×4 Latin-square design. In the growth study, mean initial and final piglet weights were 8·1 (s.e. 0·09) and 18·0 (s.e. 0·21) kg. Piglet health remained satisfactory and food intake averaged 523 (s.e. 6·7) g/day. There were no consistent and significant effects of diet type on food intake, live-weight gain or food conversion, except in week 1 when gain on diet W was higher than on diets B and SBP, 191 v. 150 v. 125 g/day, respectively (s.e.d. 20·0, P &lt; 0·05). Enzyme supplements enhanced the conversion of food to gain over 4 weeks (1·56 v. 1·50:1, s.e.d. 0·030, P &lt; 0·05). Piglets given diet SBP produced faeces with a lower dry-matter content (181 v. 246 g/kg, s.e.d. 10·8, P &lt; 0·001) but with no visual evidence of a nutritionally induced diarrhoea. There were no significant differences in apparent faecal digestibility coefficients (AFDC) for dry matter, crude protein and gross energy between diets B and SBP. AFDC for soluble, insoluble and total NSP constituent monomers were higher (P &lt; 0·001) in diet SBP. Soluble uronic acids were the most readily digested NSP constituents in diet SBP, showing a mean AFDC of 0·96 (s.e. 0·005). Apparent faecal digestibility was not an appropriate indicator for supplementary enzyme activity in the intact digestive tract of piglets given diets rich in fermentable NSPs. Piglets given the diets supplemented with enzymes excreted increased concentrations of urinary pentoses, especially arabinose (0·113 v. 0·136 mg/ml, s.e.d. 0·0107, P &lt; 0·05). Urinary arabinose and xylose concentrations were also increased (V &lt; 0·001) with feeding SBP, indicating that some of the microbially released NSP sugars escaped fermentation and were directly absorbed. In conclusion, piglets were able to use simple diets, containing high and contrasting sources of NSPs to support satisfactory rates of live-weight gain. Supplementation with NSP degrading enzymes enhanced the conversion of food to live-weight gain. Urinary NSP derived sugars provided indirect evidence of NSP hydrolysis by supplementary enzymes and gut microbes.

Influence of supplementation with cotton seed cake on body weight, parasitaemia, degree of anaemia and response to diminazene aceturate of goats infected with Trypanosoma congolense

The present study investigated the changes in levels of parasitaemia, live body weight, degree of anaemia and response to treatment with diminazene aceturate in Small East African goats infected with Trypanosoma congolense, fed either a basal ration of 500 g of fresh Napier grass only, or supplemented with 300 g of cotton seed cake per day. It was observed that the infected supplemented group had longer prepatent periods than the infected unsupplemented group and grew at a similar rate to that of the uninfected controls. The infected unsupplemented group experienced reduction in weight gain ( P<0.001) compared to their respective controls. Infection caused reduction in mean packed red cell values of both groups ( P<0.001) initially; however, the infected supplemented group showed an improvement in packed red cell volumes between 35 and 56 days post-infection unlike the infected unsupplemented group. Following treatment at 56 days post-infection, the infected supplemented group showed greater improvement in packed red cell volumes than the infected unsupplemented group, and by 4 weeks after treatment, the values in the infected supplemented and control supplemented groups were similar. It is concluded that the plane of nutrition plays an important role in the rate of live weight gain, and rate of recovery from anaemia produced by trypanosome infection. Lack of adequate nutrition that occurs under field conditions, may have an important influence on the pathogenic impact of trypanosomiasis in the Small East African breed of goats.

Effect of sward height and vertical distribution of clover on performance of cashmere goats in autumn

To investigate the effect of sward height on liveweight change in goats grazing grass/white clover swards, an experiment was conducted from mid‐August to mid‐November with groups of non‐lactating female cashmere goats that continuously grazed perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) swards. Three replicated different sward height treatments — 10–8 cm (high), 7–5 cm (medium) and 5–3 cm (low) — were used to examine the effects on the competitive ability of grass and clover components within the sward canopy and their effect on liveweight. The pasture after grazing by goats had relatively higher ryegrass leaf (+0·26, high; +0·32, medium; and +0·18, low) and lower dead ryegrass proportions (−0·28, high; −0·23, medium; and −0·18, low) than at the beginning of the experiment, whereas the white clover fraction in the sward remained constant (+0·04, high; −0·02, medium; and +0·03, low). Higher proportions of the white clover leaf lamina and petiole were found near the top of the sward canopy and were negatively correlated with the rate of liveweight gain by goats (P &lt; 0·05). Goats gained 50·2 g Live weight (LW) d−1 on the tallest treatment (high) but lost 0·01 and 42·3 g LW d−1 on the medium and low sward height treatments respectively (s.e.d. 13·21, P &lt; 0·001). Liveweight changes that occurred between sampling periods were also correlated (R2= 0·858, P &lt; 0·001) with changes in the mean sward height and proportion of white clover lamina‐petiole at the sward surface in relation to the proportion found within the whole sward. These results suggest that goat liveweight gains would be increased if another species was introduced to reduce the white clover proportion in the surface horizon.

The effect of prenatal photoperiodic history on the postnatal endocrine status of female lambs

Postnatal photoperiodic experience plays a pivotal role in determining the timing of ovarian activity in female lambs. This study examines whether a photoperiodic history gained while in utero is able to influence this timing. Pregnant Soay ewes were maintained in either long days (n = 7, 18 h light: 6 h dark; group PLD) or short days (n = 12, 6 h light: 18 h dark; group PSD) from 25 days of gestation. At birth, female lambs (n = 8 per group) were transferred to long days for 10 weeks, and then placed under short days until the end of the experiment at 38 weeks of age. Blood samples were collected from lambs on the day of birth and three times weekly for the duration of the study and the resulting plasma assayed for progesterone and prolactin. Although both gestational photoperiods produced, at best, abbreviated periods of ovarian activity, lambs born to ewes which experienced long days during gestation (group PLD) exhibited elevated plasma progesterone concentrations significantly earlier (P < 0.05) than lambs born to ewes exposed to short days during gestation (group PSD) (mean +/- SEM, 193 +/- 17 versus 244 +/- 14 days for PLD and PSD groups, respectively. Plasma prolactin concentrations in newborn lambs born between late December and early April were not affected by the ambient photoperiod, but reflected the artificial daylength experienced by their mothers during gestation. Lambs born to ewes maintained under long days during gestation (group PLD) had significantly higher prolactin concentrations on the day of birth than lambs born to ewes maintained under short days during gestation (group PSD) (45 +/- 5.4 ng/ml versus 7 +/- 3.7 ng/ml respectively, P < 0.001). The mean birth weight, rate of live weight gain and live body weight of lambs at the end of the experiment did not vary significantly between treatment groups. These results suggest that the ovine foetus is sensitive to photoperiodic information prior to birth, and develops a photoperiodic history which, under the present experimental conditions, modulates the subsequent endocrine status of the neonatal lamb.

The influence of supplementation with cotton seed cake on the resistance of Ugandan goats to primary and secondary challenges with Trypanosoma congelense and on their response to treatment

The present study investigated the influence of supplementation with cotton seed cake on the resistance of the Small East African breed of goats to primary and secondary challenges with Trypanosoma congolense and on their response to chemotherapy with diminazene aceturate. The supplemented group received 300 g of cotton seed cake per day in addition to about 500 g of fresh napier grass which was available to the unsupplemented group. It was observed that the supplemented infected (SI) group tended to sustain higher intensities of parasitaemia than the unsupplemented infected (USI) group particularly during the primary challenge and both groups showed longer prepatent periods to secondary challenge than to primary challenge. Infection caused a significant reduction in the rate of live body weight gain in the USI group compared with the unsupplemented control (USC) group whilst the SI group grew at the same rate as the supplemented control (SC) group. This effect was observed both during primary and secondary challenges. Following primary challenge, both infected groups developed similar degrees of anaemia, but the packed red cell volume (PCV) levels in the SI group improved towards the end of the first challenge and were also significantly higher than those of the USI group during the second challenge. After treatments at 56 and 126 days after infection (DAI), the greatest response was observed in PCV values. The response of the SI group was superior to that of the USI group and by 4 weeks after treatment the PCV values of the SI and SC groups were similar while those of the USI group were significantly lower than those of the USC group. It is concluded that supplementation with cotton seed cake plays an important role in the rate of live weight gain, and rate of recovery from anaemia produced by trypanosome infection in goats.

Polyethylene glycol is more effective than surfactants to enhance digestion and production in sheep fed mulga (Acacia aneura) under pen and paddock conditions

Chemicals that interfere with the formation of tannin-protein complexes were evaluated as dietary additives for mulga-fed sheep in pens and under paddock conditions. Condensed tannins (CT) in mulga inhibit protein digestion, and the use of chemicals to precipitate CT or dissociate CT-protein complexes may improve production from sheep consuming a mulga diet. In a digestion study with mulga-fed sheep in pens, provision of polyethylene glycol (PEG) at a rate of 6 g/day significantly (P &lt; 0·05) improved nitrogen (N), phosphorus (P), and sulfur (S) balance, and apparent N, P, dry matter (DM), and organic matter digestibility, and the rate of liveweight gain. Addition of the surfactants SDS or alkanate 3SL3 to the diet of mulga-fed sheep did not improve N balance or digestion; however, apparent digestibility of P, and P and S balance, were significantly improved by SDS. Teric PE64, a compound structurally similar to PEG, significantly improved S balance, but not DM intake or N balance. For sheep consuming a predominantly mulga diet under paddock conditions, provision of PEG at a rate of 12 g/day significantly improved clean wool growth and liveweight gain compared with unsupplemented sheep, by 9% and 100%, respectively (0·809 v. 0·745 mg/cm2.day, and 44 v. 22 g/day). The studies demonstrated that although surfactants can affect mulga digestion, using PEG to precipitate CT is more effective to improve mulga digestion and animal production than the use of surfactants. However, the wool and liveweight production responses achieved with PEG were not sufficient to justify its wide-scale use for mulga-fed sheep. Consequently, alternative methods should be sought to reduce the negative effects of mulga CT on sheep production.