The influence of fiber source on fiber digestion and mean retention time was investigated. Six fi... more The influence of fiber source on fiber digestion and mean retention time was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a concentrate free of fiber based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix to obtain diets containing at least 18.5% CP and 5% starch. Fecal apparent digestibility of nonstarch polysaccharides (NSPd) and its monomers, NDF, NDF-ADL, and ADF-ADL, were determined using four New Zealand White x California growing rabbits per diet. Total, ileorectal, and cecal mean retention times (tMRT, i-rMRT, and cMRT, respectively) were determined for diets based on paprika meal, olive ...
One hundred thirty New Zealand White x California rabbits were used to study the influence of the... more One hundred thirty New Zealand White x California rabbits were used to study the influence of the source of dietary fiber on several digestive criteria. Five diets were formulated to provide 10% crude fiber (CF) on a DM basis. Sixty percent of this dietary fiber was supplied by alfalfa hay, citrus pulp, beet pulp, grape marc, or rice hulls in the diets. Weights of cecal contents, cecal ammonia concentration, and molar proportion of acetic acid in diets including pulps were higher and cecal levels of DM, CP, and molar proportion of butyric acid were lower than those of the alfalfa diet. Cecal ammonia, VFA, and CF concentrations of the grape marc diet were the lowest of all the diets studied; cecal CF level and molar proportion of acetic acid were significantly higher and CP level and molar proportion of butyric acid were lower in rice hull than in alfalfa diets. Diet had no influence on daily soft feces excretion (10 g DM/d), but N contribution of soft feces to N intake was higher in...
Presence of disruptive behavioural and psychological symptoms in dementia (BPSD) is highly preval... more Presence of disruptive behavioural and psychological symptoms in dementia (BPSD) is highly prevalent and, as a consequence, neuroleptics are frequently used in these patients to control BPSD. Several reviews have shown the clinical equivalence of different classes of neuroleptics in BPSD control, although that equivalence has been only indirectly assessed by comparing the combined results of different types of active drugs versus placebo. Thus, little is known on the comparative effectiveness, head to head, of different neuroleptics on BPSD. The aim of this study was to gather preliminary information on the effectiveness of typical (haloperidol, thioridazine) and atypical (olanzapine, risperidone) neuroleptics on BPSD. Multicenter, observational and retrospective study using chart reviews of patients with dementia to assess neuroleptic prescriptions and clinical outcomes at 12 weeks on treatment. No significant differences on BPSD improvement were found by type of neuroleptic (n=78;...
The digestion and nutritive value of defatted grape seed meal (DGSM) was investigated. A basal di... more The digestion and nutritive value of defatted grape seed meal (DGSM) was investigated. A basal diet was formulated to meet requirements of growing rabbits. Another diet was formulated by substituting 15.2% of the basal diet with DGSM. Two hundred eight weaned 30-d-old rabbits were fed these diets, and fattening performance was recorded. Eighty animals were used to study the effect of DGSM inclusion on cecal fermentation traits and intestinal disaccharidase activity at two ages (5 and 35 d after weaning). Fecal apparent digestibility of nutrients was measured in 18 rabbits. A third diet was formulated to contain DGSM (61.3%) as the sole source of fiber and a supplement consisting of wheat flour, casein, lard, and a mixture of vitamins and minerals to avoid nutrient imbalances. This semipurified diet was used to determine cecal digestion traits, disaccharidase activity in the small intestine, fecal apparent digestibility of nutrients, and rate of passage in 70-d-old rabbits. Digestibl...
The influence of fiber source on fiber digestion in rabbits was investigated. Six fibrous feedstu... more The influence of fiber source on fiber digestion in rabbits was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a fiber-free concentrate, based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix, to obtain diets containing at least 3% nitrogen and 5% starch. Daily soft feces excretion, and its NDF, and total and microbial nitrogen content were determined in 60 fattening rabbits (10 per diet). Seven days after the last cecotrophy control, the same animals were used to determine weight of stomach, cecum and their contents, and cecal fermentation traits (pH, VFA and ammonia concentrations, and buffer pro...
The in vitro stimulation of lymphocytes with interleukin-2 (IL-2) generates lymphokine-activated ... more The in vitro stimulation of lymphocytes with interleukin-2 (IL-2) generates lymphokine-activated killer (LAK) cells with tumoricidal potential. In this work we studied the cytolytic capacity of LAK cells in 51 acute leukemia patients in complete remission (CR) after chemotherapy (CT), in 24 acute leukemia patients who had undergone autologous bone marrow transplantation (ABMT), and in a control group of 44 normal donors. In the normal donor control group the effect of non-IL-2-activated peripheral blood mononuclear cells (PBMC) against blast cells was always lower than 10% lysis, which we have taken as a lower limit for positive results. In 95% of post-CT patients, the lytic effect of PBMC was negative. LAK cells produced positive results in 82% of normal donors and in 37.5% of post-CT patients. The effect of PBMC against K562, i.e. natural killer (NK) activity, in post-CT patients as well as in post-ABMT patients was reduced in comparison with the average for normal donors. LAK cel...
The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isop... more The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isoproteic diets containing 26.6, 24.6, 19.0, 16.8, or 13.0% starch and 31.2, 33.4, 36.0, or 41.2% NDF, respectively (DM basis), were made by substitution of starch for NDF and fat. The effect of diet on nutrient digestibility was determined in fattening and nonlactating and lactating adult does using a total of 105 rabbits. Increasing dietary starch content linearly increased (P < .001) DM, GE, CP (P = .07), and starch digestibilities but decreased (P < .001) NDF digestibility. Nutrient digestibility was higher (P < .05), except for CP, in adult does than in fattening rabbits. Dry matter and GE digestibilities were higher (P = .08) for nonlactating than for lactating does. A lactation trial using 440 rabbit does was conducted over a 6-mo experimental period. Milk production and milk composition were measured in 70 lactations. A decrease in dietary starch content did not improve pup...
Four hundred and thirty-two Spanish Giant rabbits were fed 12 diets of variable energy to protein... more Four hundred and thirty-two Spanish Giant rabbits were fed 12 diets of variable energy to protein ratio [kcal digestible energy (DE)/g digestible crude protein (DCP)] from weaning to slaughter, both at different ages and weights. Body composition analysis for various chemical components indicated that body weight accounted for the greatest part of the variation in these constituents. Sex influenced only the N content (P less than .05). Dietary E/P accounted for greater variability in body composition than crude protein or crude fiber content of the diet. High dietary E/P increased (P less than .001) the proportion of body fat and reduced the proportion of body protein. This effect was made more obvious by adjustment to equal rate of weight gain and it showed that there may be a greater influence of dietary E/P on body composition than previously recognized.
ABSTRACT Three hundred and sixty male and female Californian ♂ × New Zealand White ♀ growing rabb... more ABSTRACT Three hundred and sixty male and female Californian ♂ × New Zealand White ♀ growing rabbits were used to study the influence of nine types of fat at 30 or 60 g/kg diet on growth and apparent digestibility. The fats used were: beef tallow (T), pork lard (L), sunflower oil (SO), two by-products from the oil-refining industry, sunflower oleins (O) and soya-bean lecithin (S), and 2: 1 (w/w) mixtures of T + S, L + S, O + S and T + O. All diets, including a diet without added fat, were formulated to a 190 g/kg acid-detergent fibre (ADF) level and to a 100 kJ digestible energy per g digestible protein ratio.As O level in the diet increased, growth was significantly impaired (P &lt; 0·001) but the other fats had no significant effect on this variable (P &gt; 0·05). A maximum oleins concentration in the diet of 10 g/kg is suggested. Excluding diets with more than 10 g oleins per kg, a significant improvement in food conversion ratio was recorded for diets containing 60 g added fat per kg (P &lt; 0·05). This improvement was related not only to a higher gross energy concentration of added-fat diets but also to a significantly (P &lt; 0·001) higher energy digestibility (0·653 v. 0·602 for 60 g/kg added-fat diets and control diet respectively). Fat addition both at 60 and 30 g/kg also improved significantly (P &lt; 0·001) dry matter, organic matter, crude protein and ether extract (EED) digestibilities. As a result, the use of ether extract in addition to ADF for estimating the energy value of diets including added fat, is proposed.An increase in the degree of unsaturation of dietary ether extract increased significantly EED (P &lt; 0·001), but did not affect other variables studied.
ABSTRACT The influence of four diets and two remating intervals (1 or 9 days after parturition) o... more ABSTRACT The influence of four diets and two remating intervals (1 or 9 days after parturition) on several milk and production traits was studied in 73 lactations of 46 Californian C? × New Zealand $ does. Three diets were formulated to provide increasing levels of fibre concentration (180, 202 and 238 g acid-detergent fibre per kg dry matter (DM)); a fourth diet contained added pork lard (35 g/kg) at the lowest level of fibre. The energy: protein ratio was maintained between 72 and 84 kj digestible energy (DE) per g digestible protein.The DE intake increased significantly when fat was included in the diet but was not affected by dietary fibre concentration. An increase in the DE content of the diet tended to decrease food conversion ratio at a mean rate of 0·16 kg/kg per MJ/kg DE. Fat addition also improved milk yield, litter weight at 21 days and survival index, mainly when litter size was higher than nine pups born alive. Neither live-weight gain nor prolificacy of does were affected by any of the variables studied.The type of diet did not affect milk DM, crude protein, fat and energy concentrations, the mean values being 287·8, 116·1, 134·2 g/kg and 27·73 MJ/kg, respectively. The proportions of short- and medium-chain fatty acids in milk fat were not affected by type of diet. The effect of fat addition on milk fat composition was limited to the long-chain fatty acids, mainly C18: 0 and C18: 1. These changes in addition to differences in milk intake could also affect the survival index of pups.Does remated 1 day after parturition showed a lower total milk yield than those remated 8 days later, the decrease being more apparent at the end of lactation. Remating interval did not affect the other variables studied.
The aim of this work was to determine what concentration of a mixture of soybean hulls and defatt... more The aim of this work was to determine what concentration of a mixture of soybean hulls and defatted grape seed meal (SHDG) could be included in diets that meet or exceed ADL and particle size require- ments for rabbits. Four isonitrogenous and isofibrous pelleted diets were formulated, with similar ADL con- centration and particle size (18.3% CP, 42.6% NDF, 7.1%
This study investigated the sulphur amino acid (SAA) requirements of rabbits. Five diets, contain... more This study investigated the sulphur amino acid (SAA) requirements of rabbits. Five diets, containing 0.48-0.72% crude SAA, were formulated by supplementing a basal diet with DL-methionine. The apparent methionine digestibility (%) was 71.4 +/- 1.1 in the basal diet and 102.9 +/- 0.9 for DL-methionine, as estimated by the difference method. Feeding trials were carried out using 370 rabbit does and 1 195 weanling rabbits slaughtered at 2-2.1 kg body weight. Milk production was measured in 80 lactations. Carcass traits were determined in 125 rabbits. The dietary SAA content affected several productive traits, such as milk production, parturition interval, growth rate, carcass quality and feed efficiency. When the diets were compared using orthogonal contrasts, a minimum requirement of 0.54% crude or 0.40% digestible SAA was determined. Further responses in performance were observed, however, when the data were analysed by regression methods. The values of crude and digestible SAA for optimal production were, respectively, 0.63 and 0.49% (rabbit does) and, at least, 0.72 and 0.58% (growing rabbits).
Seventy-five New Zealand White x Californian rabbits were used to study the influence of the chem... more Seventy-five New Zealand White x Californian rabbits were used to study the influence of the chemical composition of lucerne hay on caecal and caecotrophy characteristics. Five lucerne hays varying in chemical composition were ground and formed into pellets. These were the sole form of nutrition during the experiment. The type of lucerne hay did not affect caecal volatile fatty acid concentration, pattern of fermentation of pH. However, the caecal ammonia concentration decreased linearly (by 30% between extreme diets, P = 0.002) when dietary fibre proportion increased. The weight of caecum and caecal contents increased linearly (by 12%, P = 0.010, and 35%, P &amp;amp;lt; 0.001, respectively, between extreme diets) with dietary fibre proportion. Soft faeces excretion and contribution of soft faeces to dry matter intake were not influenced by the type of lucerne hay. The proportion of caecal content that appeared daily as soft faeces and the total and microbial nitrogen concentrations in soft faeces were higher (42, 14 and 39%, respectively) for the lucerne hay with the lowest dietary fibre proportion than for the average of the other hays.
The effect of source of carbohydrate on gut histology, digestion efficiency, and growth perfor- m... more The effect of source of carbohydrate on gut histology, digestion efficiency, and growth perfor- mance in early-weaned (25 d) rabbits at the starter period (25 to 39 d) was investigated. Six diets were factorially arranged to study the effect of partial substi- tution of starch (0, 25, or 50%) by lactose at two levels of fiber (30 or 36% NDF).
One hundred forty New Zealand White x California weanling rabbits were used to study the influenc... more One hundred forty New Zealand White x California weanling rabbits were used to study the influence of increasing dietary contents of digestible fiber replacing nonstructural carbohydrates on feed efficiency and growth performance. Four diets, formulated by replacing sugarbeet pulp (SBP) for barley grain, and two slaughter weights (2 or 2.5 kg) were used in a 4 x 2 factorial arrangement.
The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isop... more The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isoproteic diets containing 26.6, 24.6, 19.0, 16.8, or 13.0% starch and 31.2, 33.4, 36.0, or 41.2% NDF, respectively (DM basis), were made by substitution of starch for NDF and fat. The effect of diet on nutrient digestibility was determined in fattening and nonlac- tating and lactating adult does using a total of 105 rabbits. Increasing dietary starch content linearly increased (P < .001) DM, GE, CP (P = .07), and starch digestibilities but decreased (P < .001) NDF digestibility. Nutrient digestibility was higher (P < .05), except for CP, in adult does than in fattening rabbits. Dry matter and GE digestibilities were higher (P = .08) for nonlactating than for lactating does. A lactation trial using 440 rabbit does was con- ducted over a 6-m0 experimental period. Milk produc- tion and milk composition were measured in 70 lactations. A decrease in dietary starch content did not impro...
The influence of fiber source on fiber digestion and mean retention time was investigated. Six fi... more The influence of fiber source on fiber digestion and mean retention time was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a concentrate free of fiber based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix to obtain diets containing at least 18.5% CP and 5% starch. Fecal apparent digestibility of nonstarch polysaccharides (NSPd) and its monomers, NDF, NDF-ADL, and ADF-ADL, were determined using four New Zealand White x California growing rabbits per diet. Total, ileorectal, and cecal mean retention times (tMRT, i-rMRT, and cMRT, respectively) were determined for diets based on paprika meal, olive ...
One hundred thirty New Zealand White x California rabbits were used to study the influence of the... more One hundred thirty New Zealand White x California rabbits were used to study the influence of the source of dietary fiber on several digestive criteria. Five diets were formulated to provide 10% crude fiber (CF) on a DM basis. Sixty percent of this dietary fiber was supplied by alfalfa hay, citrus pulp, beet pulp, grape marc, or rice hulls in the diets. Weights of cecal contents, cecal ammonia concentration, and molar proportion of acetic acid in diets including pulps were higher and cecal levels of DM, CP, and molar proportion of butyric acid were lower than those of the alfalfa diet. Cecal ammonia, VFA, and CF concentrations of the grape marc diet were the lowest of all the diets studied; cecal CF level and molar proportion of acetic acid were significantly higher and CP level and molar proportion of butyric acid were lower in rice hull than in alfalfa diets. Diet had no influence on daily soft feces excretion (10 g DM/d), but N contribution of soft feces to N intake was higher in...
Presence of disruptive behavioural and psychological symptoms in dementia (BPSD) is highly preval... more Presence of disruptive behavioural and psychological symptoms in dementia (BPSD) is highly prevalent and, as a consequence, neuroleptics are frequently used in these patients to control BPSD. Several reviews have shown the clinical equivalence of different classes of neuroleptics in BPSD control, although that equivalence has been only indirectly assessed by comparing the combined results of different types of active drugs versus placebo. Thus, little is known on the comparative effectiveness, head to head, of different neuroleptics on BPSD. The aim of this study was to gather preliminary information on the effectiveness of typical (haloperidol, thioridazine) and atypical (olanzapine, risperidone) neuroleptics on BPSD. Multicenter, observational and retrospective study using chart reviews of patients with dementia to assess neuroleptic prescriptions and clinical outcomes at 12 weeks on treatment. No significant differences on BPSD improvement were found by type of neuroleptic (n=78;...
The digestion and nutritive value of defatted grape seed meal (DGSM) was investigated. A basal di... more The digestion and nutritive value of defatted grape seed meal (DGSM) was investigated. A basal diet was formulated to meet requirements of growing rabbits. Another diet was formulated by substituting 15.2% of the basal diet with DGSM. Two hundred eight weaned 30-d-old rabbits were fed these diets, and fattening performance was recorded. Eighty animals were used to study the effect of DGSM inclusion on cecal fermentation traits and intestinal disaccharidase activity at two ages (5 and 35 d after weaning). Fecal apparent digestibility of nutrients was measured in 18 rabbits. A third diet was formulated to contain DGSM (61.3%) as the sole source of fiber and a supplement consisting of wheat flour, casein, lard, and a mixture of vitamins and minerals to avoid nutrient imbalances. This semipurified diet was used to determine cecal digestion traits, disaccharidase activity in the small intestine, fecal apparent digestibility of nutrients, and rate of passage in 70-d-old rabbits. Digestibl...
The influence of fiber source on fiber digestion in rabbits was investigated. Six fibrous feedstu... more The influence of fiber source on fiber digestion in rabbits was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a fiber-free concentrate, based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix, to obtain diets containing at least 3% nitrogen and 5% starch. Daily soft feces excretion, and its NDF, and total and microbial nitrogen content were determined in 60 fattening rabbits (10 per diet). Seven days after the last cecotrophy control, the same animals were used to determine weight of stomach, cecum and their contents, and cecal fermentation traits (pH, VFA and ammonia concentrations, and buffer pro...
The in vitro stimulation of lymphocytes with interleukin-2 (IL-2) generates lymphokine-activated ... more The in vitro stimulation of lymphocytes with interleukin-2 (IL-2) generates lymphokine-activated killer (LAK) cells with tumoricidal potential. In this work we studied the cytolytic capacity of LAK cells in 51 acute leukemia patients in complete remission (CR) after chemotherapy (CT), in 24 acute leukemia patients who had undergone autologous bone marrow transplantation (ABMT), and in a control group of 44 normal donors. In the normal donor control group the effect of non-IL-2-activated peripheral blood mononuclear cells (PBMC) against blast cells was always lower than 10% lysis, which we have taken as a lower limit for positive results. In 95% of post-CT patients, the lytic effect of PBMC was negative. LAK cells produced positive results in 82% of normal donors and in 37.5% of post-CT patients. The effect of PBMC against K562, i.e. natural killer (NK) activity, in post-CT patients as well as in post-ABMT patients was reduced in comparison with the average for normal donors. LAK cel...
The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isop... more The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isoproteic diets containing 26.6, 24.6, 19.0, 16.8, or 13.0% starch and 31.2, 33.4, 36.0, or 41.2% NDF, respectively (DM basis), were made by substitution of starch for NDF and fat. The effect of diet on nutrient digestibility was determined in fattening and nonlactating and lactating adult does using a total of 105 rabbits. Increasing dietary starch content linearly increased (P < .001) DM, GE, CP (P = .07), and starch digestibilities but decreased (P < .001) NDF digestibility. Nutrient digestibility was higher (P < .05), except for CP, in adult does than in fattening rabbits. Dry matter and GE digestibilities were higher (P = .08) for nonlactating than for lactating does. A lactation trial using 440 rabbit does was conducted over a 6-mo experimental period. Milk production and milk composition were measured in 70 lactations. A decrease in dietary starch content did not improve pup...
Four hundred and thirty-two Spanish Giant rabbits were fed 12 diets of variable energy to protein... more Four hundred and thirty-two Spanish Giant rabbits were fed 12 diets of variable energy to protein ratio [kcal digestible energy (DE)/g digestible crude protein (DCP)] from weaning to slaughter, both at different ages and weights. Body composition analysis for various chemical components indicated that body weight accounted for the greatest part of the variation in these constituents. Sex influenced only the N content (P less than .05). Dietary E/P accounted for greater variability in body composition than crude protein or crude fiber content of the diet. High dietary E/P increased (P less than .001) the proportion of body fat and reduced the proportion of body protein. This effect was made more obvious by adjustment to equal rate of weight gain and it showed that there may be a greater influence of dietary E/P on body composition than previously recognized.
ABSTRACT Three hundred and sixty male and female Californian ♂ × New Zealand White ♀ growing rabb... more ABSTRACT Three hundred and sixty male and female Californian ♂ × New Zealand White ♀ growing rabbits were used to study the influence of nine types of fat at 30 or 60 g/kg diet on growth and apparent digestibility. The fats used were: beef tallow (T), pork lard (L), sunflower oil (SO), two by-products from the oil-refining industry, sunflower oleins (O) and soya-bean lecithin (S), and 2: 1 (w/w) mixtures of T + S, L + S, O + S and T + O. All diets, including a diet without added fat, were formulated to a 190 g/kg acid-detergent fibre (ADF) level and to a 100 kJ digestible energy per g digestible protein ratio.As O level in the diet increased, growth was significantly impaired (P &lt; 0·001) but the other fats had no significant effect on this variable (P &gt; 0·05). A maximum oleins concentration in the diet of 10 g/kg is suggested. Excluding diets with more than 10 g oleins per kg, a significant improvement in food conversion ratio was recorded for diets containing 60 g added fat per kg (P &lt; 0·05). This improvement was related not only to a higher gross energy concentration of added-fat diets but also to a significantly (P &lt; 0·001) higher energy digestibility (0·653 v. 0·602 for 60 g/kg added-fat diets and control diet respectively). Fat addition both at 60 and 30 g/kg also improved significantly (P &lt; 0·001) dry matter, organic matter, crude protein and ether extract (EED) digestibilities. As a result, the use of ether extract in addition to ADF for estimating the energy value of diets including added fat, is proposed.An increase in the degree of unsaturation of dietary ether extract increased significantly EED (P &lt; 0·001), but did not affect other variables studied.
ABSTRACT The influence of four diets and two remating intervals (1 or 9 days after parturition) o... more ABSTRACT The influence of four diets and two remating intervals (1 or 9 days after parturition) on several milk and production traits was studied in 73 lactations of 46 Californian C? × New Zealand $ does. Three diets were formulated to provide increasing levels of fibre concentration (180, 202 and 238 g acid-detergent fibre per kg dry matter (DM)); a fourth diet contained added pork lard (35 g/kg) at the lowest level of fibre. The energy: protein ratio was maintained between 72 and 84 kj digestible energy (DE) per g digestible protein.The DE intake increased significantly when fat was included in the diet but was not affected by dietary fibre concentration. An increase in the DE content of the diet tended to decrease food conversion ratio at a mean rate of 0·16 kg/kg per MJ/kg DE. Fat addition also improved milk yield, litter weight at 21 days and survival index, mainly when litter size was higher than nine pups born alive. Neither live-weight gain nor prolificacy of does were affected by any of the variables studied.The type of diet did not affect milk DM, crude protein, fat and energy concentrations, the mean values being 287·8, 116·1, 134·2 g/kg and 27·73 MJ/kg, respectively. The proportions of short- and medium-chain fatty acids in milk fat were not affected by type of diet. The effect of fat addition on milk fat composition was limited to the long-chain fatty acids, mainly C18: 0 and C18: 1. These changes in addition to differences in milk intake could also affect the survival index of pups.Does remated 1 day after parturition showed a lower total milk yield than those remated 8 days later, the decrease being more apparent at the end of lactation. Remating interval did not affect the other variables studied.
The aim of this work was to determine what concentration of a mixture of soybean hulls and defatt... more The aim of this work was to determine what concentration of a mixture of soybean hulls and defatted grape seed meal (SHDG) could be included in diets that meet or exceed ADL and particle size require- ments for rabbits. Four isonitrogenous and isofibrous pelleted diets were formulated, with similar ADL con- centration and particle size (18.3% CP, 42.6% NDF, 7.1%
This study investigated the sulphur amino acid (SAA) requirements of rabbits. Five diets, contain... more This study investigated the sulphur amino acid (SAA) requirements of rabbits. Five diets, containing 0.48-0.72% crude SAA, were formulated by supplementing a basal diet with DL-methionine. The apparent methionine digestibility (%) was 71.4 +/- 1.1 in the basal diet and 102.9 +/- 0.9 for DL-methionine, as estimated by the difference method. Feeding trials were carried out using 370 rabbit does and 1 195 weanling rabbits slaughtered at 2-2.1 kg body weight. Milk production was measured in 80 lactations. Carcass traits were determined in 125 rabbits. The dietary SAA content affected several productive traits, such as milk production, parturition interval, growth rate, carcass quality and feed efficiency. When the diets were compared using orthogonal contrasts, a minimum requirement of 0.54% crude or 0.40% digestible SAA was determined. Further responses in performance were observed, however, when the data were analysed by regression methods. The values of crude and digestible SAA for optimal production were, respectively, 0.63 and 0.49% (rabbit does) and, at least, 0.72 and 0.58% (growing rabbits).
Seventy-five New Zealand White x Californian rabbits were used to study the influence of the chem... more Seventy-five New Zealand White x Californian rabbits were used to study the influence of the chemical composition of lucerne hay on caecal and caecotrophy characteristics. Five lucerne hays varying in chemical composition were ground and formed into pellets. These were the sole form of nutrition during the experiment. The type of lucerne hay did not affect caecal volatile fatty acid concentration, pattern of fermentation of pH. However, the caecal ammonia concentration decreased linearly (by 30% between extreme diets, P = 0.002) when dietary fibre proportion increased. The weight of caecum and caecal contents increased linearly (by 12%, P = 0.010, and 35%, P &amp;amp;lt; 0.001, respectively, between extreme diets) with dietary fibre proportion. Soft faeces excretion and contribution of soft faeces to dry matter intake were not influenced by the type of lucerne hay. The proportion of caecal content that appeared daily as soft faeces and the total and microbial nitrogen concentrations in soft faeces were higher (42, 14 and 39%, respectively) for the lucerne hay with the lowest dietary fibre proportion than for the average of the other hays.
The effect of source of carbohydrate on gut histology, digestion efficiency, and growth perfor- m... more The effect of source of carbohydrate on gut histology, digestion efficiency, and growth perfor- mance in early-weaned (25 d) rabbits at the starter period (25 to 39 d) was investigated. Six diets were factorially arranged to study the effect of partial substi- tution of starch (0, 25, or 50%) by lactose at two levels of fiber (30 or 36% NDF).
One hundred forty New Zealand White x California weanling rabbits were used to study the influenc... more One hundred forty New Zealand White x California weanling rabbits were used to study the influence of increasing dietary contents of digestible fiber replacing nonstructural carbohydrates on feed efficiency and growth performance. Four diets, formulated by replacing sugarbeet pulp (SBP) for barley grain, and two slaughter weights (2 or 2.5 kg) were used in a 4 x 2 factorial arrangement.
The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isop... more The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isoproteic diets containing 26.6, 24.6, 19.0, 16.8, or 13.0% starch and 31.2, 33.4, 36.0, or 41.2% NDF, respectively (DM basis), were made by substitution of starch for NDF and fat. The effect of diet on nutrient digestibility was determined in fattening and nonlac- tating and lactating adult does using a total of 105 rabbits. Increasing dietary starch content linearly increased (P < .001) DM, GE, CP (P = .07), and starch digestibilities but decreased (P < .001) NDF digestibility. Nutrient digestibility was higher (P < .05), except for CP, in adult does than in fattening rabbits. Dry matter and GE digestibilities were higher (P = .08) for nonlactating than for lactating does. A lactation trial using 440 rabbit does was con- ducted over a 6-m0 experimental period. Milk produc- tion and milk composition were measured in 70 lactations. A decrease in dietary starch content did not impro...
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