The effect of reducing energy density, via the addition of water to dry diet, on body weight and activity in dogs.

Approximately 40 % of pet dogs are estimated to be overweight and this is associated with health conditions significantly reducing life span and quality. In cats, dietary energy dilution has been reported to increase activity levels and aid healthy body-weight maintenance. Our aim was to investigate this in dogs. For 28 d, a complete and balanced standard dry diet, hydrated to a total moisture content (TMC) of 72 %, was offered to forty-six dogs at individual maintenance energy requirements (MER). Intake, body weight and activity were measured. For the following 28 d, the dry diet was offered at 200 % of MER with or without hydration (7·6 or 72 % TMC) and measurements repeated. When offered diets in excess, body weight increased significantly faster (19·3 g/d) with the hydrated diet (P = 0·001), but activity levels did not change from baseline (P = 0·392), while activity reduced significantly with the dry diet (about 15 %; P < 0·001). Dogs completely compensated for the reduction of dietary energy content, indicating that this is not a useful strategy for maintaining body weight when offered excess food.

Effects of feeding alfalfa stemlage or wheat straw for dietary energy dilution on nutrient intake and digestibility, growth performance, and feeding behavior of Holstein dairy heifers.

Feeding high-quality forage diets may lead to excessive weight gains and over-conditioning for dairy heifers. Restriction of energy density and dry matter intake by using low-energy forages, such as straw, is a good approach for controlling this problem. Alfalfa stems contain high fiber and moderate protein content and have the potential to be used to replace straw to reduce dietary energy. The objective of this study was to compare nutrient intakes, digestibilities, growth performance, and feeding behaviors of dairy heifers offered an alfalfa silage/corn silage high-energy diet (HE; 13.1% crude protein, 65.4% total digestible nutrients, 39.7% neutral detergent fiber) with 2 energy-diluted diets that replaced various proportions of the corn or alfalfa silages with either alfalfa stemlage (STM; 12.6% crude protein, 59.1% total digestible nutrients, 46.4% neutral detergent fiber) or chopped wheat straw (WS; 12.6% crude protein, 61.9% total digestible nutrients, 43.7% neutral detergent fiber). Seventy-two pregnant Holstein heifers (16.8 ± 1.3 mo) were stratified into 3 blocks (24 heifers/block) by initial body weight (light, 440 ± 18.0 kg; medium, 486 ± 18.6 kg; heavy, 534 ± 25.1 kg), with each block composed of 3 pens (8 heifers/pen), with diets assigned randomly to 1 pen within the block. Diets were offered in a 56-d feeding trial. Both dry matter intake and energy intake were decreased with the addition of low-energy forages to the diets, but no differences in dry matter intake were observed across diluted diets. Digestibility of dry matter, organic matter, neutral detergent fiber, and apparent N were greater for HE compared with diluted diets, and for WS compared with STM. Total body weight gain (74 vs. 56 kg) and average daily gain (1.32 vs. 1.00 kg/d) were greater for heifers offered HE compared with diluted diets. Feed efficiency tended to be less for heifers offered the diluted diets compared with HE (10.7 vs. 8.6 kg of feed/kg of gain). Heifers did not sort for or against particles when offered HE. However, increased sorting behavior was observed for diluted diets. Compared with ad libitum feeding dairy heifers a diet with high nutrient content forages (corn silage and alfalfa silage), use of diet diluted with alfalfa stemlage or wheat straw is an effective feeding management strategy to control total daily dry matter and energy intake by increasing gut fill, and maintain desirable body condition and growth rates, even though the diluted diets had greater sortability.

Growth performance and sorting characteristics of corn silage-alfalfa haylage diets with or without forage dilution offered to replacement Holstein dairy heifers.

Gravid heifers consuming high-quality forage diets are susceptible to excessive weight gains and overconditioning. One approach for controlling this problem is to dilute diets with low-energy forages, such as straw, that reduce the caloric density and dry matter intake (DMI) of that diet by heifers. These diluting agents are often sortable by dairy heifers, but previous visual evidence has suggested that eastern gamagrass haylage may be a nonsortable alternative. Our objectives were (1) to compare the growth performance of dairy heifers offered a high-quality forage diet (control) with diets containing 1 of 3 diluting agents [eastern gamagrass haylage (EGH), chopped wheat straw (WS), or chopped corn fodder (CF)]; and (2) evaluate sorting behaviors of heifers offered these forage diets. Holstein heifers (n=128) were stratified (32 heifers/block) on the basis of initial body weight (heavy, 560 ± 27.7 kg; medium-heavy, 481 ± 17.7 kg; medium-light, 441 ± 22.0 kg; and light, 399 ± 14.4 kg), and then assigned to 1 of 16 identical research pens (4 pens/block; 8 heifers/pen), where each of the 4 research diets were assigned to 1 pen within each block. Diets were offered in a 118-d feeding trial with heifers crowded to 133% of capacity at the feed bunk. Inclusion of low-energy forages was effective in reducing both diet energy density and DMI. Concentrations of physically effective fiber (pef) particles did not change during the 24-h period following feeding for either the control or EGH diets; however, this response for pef particles masked the competing (and cancelling) responses for individual large and medium particles, which heifers sorted with discrimination and preference, respectively. Sorting against pef particles was detected for WS, and much more severely for the CF diet. Sorting of forage particles by heifers could not be related to heifer performance. Compared with control (1.16 kg/d), average daily gains (ADG) were reduced by dilution in all cases, but were virtually identical between EGH (0.98 kg/d) and CF (0.97 kg/d), which exhibited no sorting and extensive sorting of pef, respectively. Furthermore, ADG for WS was approximately 0.2 kg/d less than EGH or CF, despite exhibiting sorting characteristics intermediate between EGH and CF. Diets diluted with low-energy forages were formulated to be isonitrogenous and isocaloric; within that context, WS was most effective in reducing DMI and maintaining ADG within typical recommendations for Holstein heifers.

Is gastrointestinal plasticity in king quail (Coturnix chinensis) elicited by diet-fibre or diet-energy dilution?

Phenotypic plasticity of organ size allows some animals to manage fluctuations of resource quality or availability. Here, we examined the phenotypic plasticity of the gastrointestinal tract of king quail (Coturnix chinensis) in a diet-fibre manipulation study. Quail were offered either a control low-fibre (high-quality) food (8.5% neutral-detergent fibre; NDF), or one of two experimental diets of higher fibre contents of 16% NDF (i.e. low-quality food). To examine whether phenotypic plasticity of organ size was associated with the fibre content per se, or as a consequence of diluting the diet energy contents by adding fibre, one of the high-fibre feeds was 'balanced' with additional energy to match that of the low-fibre control diet. Total empty dry mass of the gastrointestinal tract was significantly heavier among birds offered the unbalanced high-fibre diet as compared with those offered the control diet, with birds offered the fibrous but energy-balanced diet having guts of intermediate size. The heavier entire-gut mass (dry) of quail offered the unbalanced high-fibre diet was associated mainly with these birds having significantly heavier gizzards. Notably, the larger gizzard in the birds offered the unbalanced high-fibre diet was associated with marked increases in their metabolisability (digestion) of diet fibre. Our findings suggest that the available energy in the diet may be more important for eliciting phenotypic changes in the gut of these herbivorous birds rather than simple physical effects of diet fibre on feed intakes or on muscular compensation to fibrous ingesta.

Qualitative feed restriction for heavy swines: effect on digestibility and weight of organs of digestive tract, and environmental impact of feces / Restrição alimentar qualitativa para suínos pesados: efeito sobre digestibilidade e peso dos órgãos do trato digestório e impacto ambiental das fezes

A total of 50 barrows were used to evaluate qualitative feed restriction on digestibility of dietary components, weight of organs of digestive tract, and composition and production of feces. Five experimental diets, with increasing levels of qualitative feed restriction of 0, 5, 10, 15, and 20 percent were used. There was linear reduction (P<0.001) of all digestibility coefficients on the levels of qualitative feed restriction, except for acid detergent fiber, which presented a quadratic response (P<0.05). Contents of total solids (P<0.01), volatile solids (P<0.05), and total minerals (P<0.001) in the feces augmented with increasing levels of qualitative feed restriction, whereas the levels of K (P<0.05), Cu (P<0.01), N, P, Na, Ca, Mg, Fe, and Zn (P<0.001) presented a quadratic response. Daily feces excretion; and contents of total solids, volatile solids, total minerals, and levels of N, P, K, Mn, and Cu (P<0.001) and Ca, Na, Mg, and Fe (P<0.05) presented a clear increase in function of the qualitative feed restriction level. Qualitative feed restriction can be an alternative for the disposal of agribusiness waste, providing good crop-fertilizing by the use of swine feces.

Foram utilizados 50 suínos machos castrados para avaliar o efeito da restrição alimentar qualitativa sobre a digestibilidade dos componentes dietéticos, os órgãos do trato digestório, a composição e a produção fecal. Foram utilizadas cinco dietas experimentais, com níveis de restrição qualitativa de 0, 5, 10, 15 e 20 por cento. Houve redução linear (P<0,001) para todos os coeficientes de digestibilidade, com exceção da fibra em detergente ácido, que apresentou resposta quadrática (P<0,05). Os teores de sólidos totais (P<0,01) e voláteis (P<0,05), e minerais totais (P<0,001) nas fezes aumentaram com os níveis de restrição alimentar, enquanto os níveis de K (P<0,05), Cu (P<0,01) e de N, P, Na, Ca, Mg, Fe e Zn (P<0,001), apresentaram resposta quadrática. A excreção diária de fezes, sólidos totais e voláteis, minerais totais, N, P, K, Mn e Cu (P<0,001), Ca, Na, Mg e Fe (P<0,05) apresentaram aumento em função do nível da restrição alimentar qualitativa. A restrição qualitativa pode ser alternativa para destinação de resíduos da agroindústria, conferindo boas propriedades às fezes suínas, no que diz respeito à utilização para adubação de culturas.