Voluntary feed intake in growing-finishing pigs: A review of the main determining factors and potential approaches for accurate predictions

2004 ◽  
Vol 84 (4) ◽  
pp. 549-566 ◽  
Author(s):  
C. M. Nyachoti ◽  
R. T. Zijlstra ◽  
C. F. M. de Lange ◽  
J. F. Patience

The ability of pigs to consume sufficient nutrients for optimal performance is an important consideration in commercial pork production. Nutrient intake levels are directly related to voluntary feed intake. Voluntary feed intake in pigs is influenced by several factors including environmental conditions (e.g. thermal and social conditions), animal status (e.g., age and physiological status), and feed and feeding conditions (e.g. bulkiness of the feed and feed form). Although the individual effects of many of these factors on voluntary feed intake have been investigated and quantified, little has been done to characterize their interactive effects. Under commercial conditions, voluntary feed intake is clearly influenced by multiple factors at any one time. Thus, there is a need for a means to accurately quantify voluntary feed intake in pigs as affected by the different interacting factors. Until quantitative effects of these interactions are established it is suggested that feed intake be monitored. This can be achieved by obtaining feed intake on representative groups of pigs. Key words: Voluntary feed intake, pigs, determining factors, prediction equations

Author(s):  
W. Polviset ◽  
N. Danopas

Background: Agricultural productivity in Southeast Asian countries are important to produce food for human, thus the first priority to improve agricultural productivity is feed and feeding in livestock, especially in ruminants when rice straw and Napier grass are used as the roughage sources; in addition, cassava leaves and Leucaena leaves can be used as the protein sources. Interestingly, the strategy to improve feed in ruminant is through the use of total mixed rations (TMR) which are produced by combination of roughages, concentrates, minerals, vitamins and additives. Methods: During the period 2020-2021 a study with 2 × 2 factorial, in 4 × 4 Latin square design with 21 days per period tested the following TMR’s T1- 5% urea treated rice straw with dried Leucaena leaves, T2- 5% urea treated rice with dried cassava leaves, T3- fermented napier grass with dried Leucaena leaves and the T4- fermented napier grass with dried cassava leaves on voluntary feed intake, nutrient intake and blood metabolites in Black Bengal goats. Result: All treatments did not affect voluntary feed intake (kgDM/head/day and % BW) (P greater than 0.05), but feeding with 5% urea treated rice with dried cassava leaves, it was non significantly higher (0.71 kgDM/day). Furthermore, nutrient intake of organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and rumination were not affected among all the four treatments (P greater than 0.05). Additionally, blood glucose, blood urea nitrogen and triglyceride concentrations in plasma were not influenced due to treatments (P greater than 0.05). Nevertheless, Feed cost (USD/kg) was reduced T3 and T4. In conclusion, feeding Black Bengal goat with fermented napier grass with dried Leucaena leaves and fermented napier grass with dried cassava leaves in the TMR were suitable because of the lowest price (0.13 USD/kg) when compared to the other treatments.


1961 ◽  
Vol 12 (1) ◽  
pp. 176 ◽  
Author(s):  
PG Schinckel ◽  
BF Short

The effect of high and lox- levels of feed intake during pregnancy in ewes, and from birth to 4 months of age in their lambs, on adult body weight and wool production has been studied. As compared with the corresponding high intake groups, lambs from the low intake ewes were 34% smaller at birth and 9% smaller at maturity. They also had c. 15% fewer wool follicles per sheep, and produced c. 8.5% less wool as adults. Low levels of feed intake between birth and 4 months resulted in a slower growth rate and a reduction (c. 10%) in mature body weight. The maturation of the follicle population was delayed by a low feed intake in this period but no permanent reduction in numbers was observed. The post-natal low intake group produced c. 12% less wool as adults, owing to a smaller (c. 10.5%) fibre weight. The major effect on wool growth potential of low levels of nutrient supply during pre-natal life was a restriction of body size and total number of follicles, while restriction of nutrient intake during early post-natal life reduced the capacity of the individual follicles to produce fibre.


2013 ◽  
Vol 155 (2-3) ◽  
pp. 277-284 ◽  
Author(s):  
Saymore P. Ndou ◽  
Archibold G. Bakare ◽  
Michael Chimonyo

1996 ◽  
Vol 47 (2) ◽  
pp. 277
Author(s):  
RA Dynes

Managing voluntary feed intake of grazing animals is essential to maximise returns and to meet market specifications. Restricting nutrient intake is successfully achieved by controlled grazing management techniques and with feed additive use in intensive feeding systems. Increasing feed intake in the long-term will be a greater challenge to research. There is considerable potential with existing genotypes of sheep to increase intake, because intake appears to be limited by a lack of hunger drive rather than by limitations due to tissue energy transactions or gut load. Increasing voluntary feed intake will be successful if we can increase the hunger drive within the brain. Increasing the hunger drive may be achieved by decreasing the metabolic satiety signal arising from tissue transactions, by reducing the magnitude of the satiety signals arising from the gastrointestinal tract or by modifying neurotransmitters within the brain to enhance the hunger drive.


Author(s):  
S.A. Chadd ◽  
D.J.A. Cole

There have been a number of reports that voluntary feed intake (VFI) of modern pig genotypes may be the limitation to their growth performance. It has been suggested that selection for leanness (Fowler et al. 1976) and breeding for faster growth may have reduced appetite.In addition there is only limited information about the effect on VFI, performance and carcass characteristics of pigs fed ad libitum to liveweights greater than 100kg. A study was therefore undertaken to compare VFI and energy intake of improved genotypes with predicted intakes based on earlier genotypes (ARC, 1981). The associated effects on performance and carcass characteristics at heavier slaughter weights were also studied.


1998 ◽  
Vol 78 (1) ◽  
pp. 15-21 ◽  
Author(s):  
E. K. Okine ◽  
G. W. Mathison ◽  
M. Kaske ◽  
J. J. Kennelly ◽  
R. J. Christopherson

Simultaneous abolition of the motility of the ruminoreticulum (RR) and digesta passage from the RR by bilateral vagotomy indicate that the motility of the RR coordinated with quiescence of the reticulo-omasal orifice (ROO) are prerequisite for caudal movement of digesta from the RR and forestomach. Rate of passage is of importance in ruminant animals since it is related to maximal voluntary feed intake, extent of digestion of the diet, amount of protein which bypasses the rumen, efficiency of microbial growth, extent of methane loss, and susceptibility of animals to bloat. In a series of studies, we clarified the roles of frequency, pressure and duration of reticular contractions and the function of the ROO in controlling digesta flow from the rumen in response to changes in diets, environmental conditions and physiological status. Variability in amount of NDF and OM transferred per contraction suggests that frequency of reticular contraction is not the rate-limiting step in digesta passage from the rumen. This concept is supported by our finding that the relaxation of the ROO is not always coincidental with reticular electromyographic activity in solid meal-fed relative to milk fed sheep. The magnitude of reticular pressure may not precisely control digesta passage through the ROO as the amount of OM and NDF associated with each centimetre of pressure during contraction varies from 1.2 to 1.4 and from 0.9 to 2.5 g. On the other hand, the amount of OM and NDF passed per second of reticulum contraction varies only from 0.3 to 0.6 and from 0.2 to 0.3 g, respectively, in cattle. In addition, a 38% decrease in mean retention time of particulate matter in the rumen was associated with a 14% increase in duration of reticular contraction in cattle. Similarly, quiescence of the ROO increased from 2.9 to 3.3 s in sheep when feed intake increased from maintenance to twice maintenance. We suggest that duration of reticular contractions may be more closely related to digesta flow than is either frequency or pressure changes. We also suggest that the ruminant animal can influence reticular contraction characteristics and duration of the quiescence of the ROO in response to various stimuli and that reticular contractions are coordinated with other diet and physiological demands for optimal transfer efficiency of digesta from the RR. Key words: Digesta passage, reticular contractions, reticulo-omasal orifice, electromyographic activity


Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 701
Author(s):  
Yi Wan ◽  
Ruiyu Ma ◽  
Anam Khalid ◽  
Lilong Chai ◽  
Renrong Qi ◽  
...  

One of the most important factors that determine feed utilization by chickens is the feed form. Although it is generally believed that pellet diets have a positive effect on chicken growth, there are some studies that have indicated no difference between pellet and mash on chickens performance. This study was conducted to assess the effects of feed form on production performance, egg quality, nutrient metabolism and intestinal morphology in two breed laying hens. Two hundred and sixteen 25-week-old Hy-Line brown (n = 108) and Hy-Line grey (n = 108) hens were selected. Each breed was randomly allocated into two treatments with 6 replications (9 birds in each replication), which were fed mash and pellet diets, respectively. Production performances were recorded daily and egg quality traits were measured every two weeks. At 42 weeks of age, one bird per replication from each experimental group was selected for metabolism determination and intestine morphology observation. Compared with mash diets, pellet diets improved laying rate (p < 0.05), ADFI (average daily feed intake, p < 0.05), egg weight, shell strength, yolk proportion and Haugh unit (p < 0.05) in both breeds and reduced the FCR (feed conversion ratio, p < 0.05) in Hy-Line grey. The apparent digestibility of DM% (dry matter) and CP% (crude protein) were significantly higher (p < 0.05) in both breed laying hens fed pellet than those fed mash. The apparent digestibility of P% (phosphorus) and Ca% (calcium) was higher in Hy-Line grey fed pellet and was higher in Hy-Line brown fed mash. Compared to mash diets, pellet diets increased the VH (villus height), CD (crypt depth) and VCR (ratio of villus height to crypt depth) of the small intestine of Hy-Line grey, and increased the VH and CD of duodenum and ileum of Hy-Line brown. Overall, pellet diets improved production performance and nutrition metabolism through positive changes in the laying rate, feed intake, egg albumen quality and apparent digestibility of laying hens. The current findings provided support for the advantages of feeding pellets during the peak egg laying period for the two popular laying hen strains, Hy-Line brown and Hy-Line grey.


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