Effects of lasalocid and protein levels on feed intake and growth rate of Awassi lambs

1997 ◽  
Vol 1997 ◽  
pp. 187-187
Author(s):  
M. M. Muwalla ◽  
M. Y. Harb ◽  
T. F. Crosby

Lasalocid is a polyether antibiotic derived from the fermentation of streptomyces lasaliensis used as a coccidiostat in sheep. There are varying literature reports on lamb growth rate and feed intake when lasalocid is included in the diet of feedlot lambs. While some reports have shown that lasalocid enhances feed efficiency in ruminants by decreasing feed intake and either maintaining or improving rate of gain others indicate that lasalocid did not have any effect on lamb growth rates or feed efficiency (Stobart et al., 1987). Also, when lasalocid was fed to Chios lambs, growth rate was increased but there was no improvement in feed conversion efficiency (Hadjipanayiotou et al., 1988). There are no published data in the literature relating to the use of lasalocid as a growth promoter in the Awassi breed of sheep fed complete diets and the purpose of this study was to investigate the effect of lasalocid with two levels of protein on the growth rate and feed efficiency of weaned male and female Awassi lambs.

1970 ◽  
Vol 12 (3) ◽  
pp. 403-412 ◽  
Author(s):  
I. A. M. Lucas ◽  
K. L. Miles

SUMMARYIn the national pig progeny test stations one diet is given up to about 55 kg live weight and another, with less protein, is given from then until slaughter. These diets were compared with four ‘single’ diets, similar in digestible-energy content, but containing either 15·6, 17·4, 18·7 or 22·1% crude protein, and each given unchanged from 18 to 93 kg live weight. There were twenty groups of one castrate and one gilt on each treatment.Pigs given the lowest protein levels had the poorest growth rates and feed conversion efficiency up to 57 kg live weight, but the best from 57 to 93 kg. Hence there were no differences in overall feed efficiency, and overall growth rate was only slightly less with the lowest protein level than with other treatments.Carcass leanness rose with protein level in the ‘single’ diets over the range 15·6·18·7% crude protein, but a further increase to 22·1% reduced leanness.Pigs given the progeny test diets had carcasses intermediate in composition to those of pigs on the ‘single’ diets with 17·4% and 18·7% protein.


2004 ◽  
Vol 84 (2) ◽  
pp. 177-185 ◽  
Author(s):  
F. S. Schenkel ◽  
S. P. Miller ◽  
J. W. Wilton

Genetic associations between feed efficiency, growth, and live ultrasound measured body composition traits were studied in purebred beef bulls of six breeds in Ontario bull test stations from 1991 to 2000. Feed traits included average daily feed intake (FI), feed conversion ratio (FCR), and residual feed intake [feed intake adjusted for production alone (RFIp) or production and backfat thickness (RFIb)]. Growth traits were average daily weight gain (ADG), mid-test metabolic weight (MW), hip height (HH), and scrotal circumference (SC). Body composition traits included ultrasound backfat thickness (BF), longissimus muscle area (LMA), and predicted percentage of intramuscular fat (IFAT). Bulls were measured every 28 d for weight and individual feed intake, and at the end of test for ultrasound body composition traits. Number of records per trait ranged from 2284 (FI) to 13 319 (ADG). Fixed effects of test group, breed and end of test age (within breed), and random effects of animal and herd of origin were modeled using REML bivariate analyses for all traits. Heritability estimates were moderate for all traits (0.30 to 0.55), except for IFAT (0.14). The genetic correlation between RFIp and RFIb was high (0.99) within breeds, but breeds ranked differently with respect to RFIp and RFIb. Genetic correlations of RFIb with ADG and backfat thickness were essentially zero, which indicate that selection on residual feed intake could be implemented to reduce feed intake and improve feed conversion without compromising growth or changing levels of subcutaneous fat. Key words: Central test, genetic correlation, heritability, residual feed intake


1999 ◽  
Vol 1999 ◽  
pp. 47-47
Author(s):  
R.M. Herd ◽  
S.C. Bishop

Net feed efficiency refers to variation in feed consumption between animals net of requirements for maintenance and production, and may be measured as residual feed intake (RFI). Because RFI is independent of liveweight (LW) and growth rate, selection for improved net feed efficiency is likely to reduce feed intake with little change in growth. The purpose of this study was to establish whether there exists genetic variation in RFI in young British Hereford bulls, and to determine the phenotypic and genetic correlations of RFI with key production traits.The data consisted of performance measurements on 540 bull progeny of 154 British Hereford sires, collected over ten 200-day postweaning performance tests conducted between 1979 and 1988. The traits analysed were food intake (FI), 200 to 400-day daily gain (ADG), 400-day weight (W400), predicted carcass lean content (LEAN), lean growth rate (LGR), food conversion ratio (FI/ADG) and lean FCR (LFCR; FI/(ADG x LEAN), described by Bishop (1992).


Dairy ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 684-694
Author(s):  
Lenka Krpálková ◽  
Niall O’Mahony ◽  
Anderson Carvalho ◽  
Sean Campbell ◽  
Gerard Corkery ◽  
...  

Identification of the associations of cow feed efficiency with feeding behaviour and milk production is important for supporting recommendations of strategies that optimise milk yield. The objective of this study was to identify associations between measures of feed efficiency, feed intake, feeding rate, rumination time, feeding time, and milk production using data collected from 26 dairy cows during a 3 month period in 2018. Cows averaged (mean ± standard deviation) 2.2 ± 1.7 lactations, 128 ± 40 days in milk, 27.5 ± 5.5 kg/day milk, 1.95 ± 0.69 kg feed/1 kg milk—the measure used to express feed conversion ratio (FCR), 575 ± 72 min/day rumination time, and 264 ± 67 min/day feeding time during the observation period. The coefficient of variation for rumination time (min/d) was 12.5%. A mixed linear model was selected for analyses. The most feed inefficient cows with the highest FCR (≥2.6 kg feed/1 kg milk) showed the lowest milk yield (24.8 kg/day), highest feed intake (78.8 kg), highest feeding rate (0.26 kg/min) and BCS (3.35 point). However, the relative milk yield (milk yield per 100 kg of body weight) was the highest (4.01 kg/day) in the most efficient group with the lowest FCR (≤1.4 kg feed/1 kg milk). Our study showed that the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk) had the highest rumination time (597 min/day; p < 0.05), feeding time (298 min/day; p < 0.05), rumination/activity ratio (4.39; p < 0.05) and rumination/feeding ratio (2.04; p < 0.05). Less active cows (activity time 164 min/day; p < 0.05) were the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk). The behavioural differences observed in this study provide new insight into the association of feed behaviour and feed efficiency with milk performance. Incorporating feeding behaviour into the dry matter intake model can improve its accuracy in the future and benefit breeding programmes.


Author(s):  
Tsukasa Yoshidomi ◽  
Kazuaki Tanaka ◽  
Tatsuya Takizawa ◽  
Satoshi Nikaido ◽  
Tetsuya Ito ◽  
...  

Copy number variation (CNV) of the AMY gene in humans has been enthusiastically studied for its association with starch digestibility and obesity. The alpha-amylase (AMY) is a major starch digestive enzyme in mammals. This study aimed to determine the association between CNV of the porcine pancreatic amylase (AMY2B) gene and feed efficiency. Improvement of feed efficiency in growing pigs is of great economic interest. We assayed the copy number of AMY2B by using real-time quantitative PCR (qPCR) in a Large White pig population. We identified three genotypes for AMY2B CNVs, namely I/I (homozygotes of haplotype I; a chromosome with one copy of AMY2B), I/II (heterozygotes of haplotype I and II; a chromosome with two copies) and II/II (homozygotes of haplotype II). We tested the genotypes of the parental generation consisting of six males, 21 females and 265 offspring piglets to validate the AMY2B CNV genotyping. With very few mistyping exceptions, copy numbers of AMY2B were transmitted to piglets in segregation ratios following Mendelian inheritance. Finally, we performed an association analysis between the CNV of the AMY2B gene and feed efficiency traits in 207 uncastrated male pigs. The generalised linear model analysis showed the significant effects of AMY2B CNV genotype on average daily feed intake, total feed intake and feed conversion ratio during growth from 30 kg to 100 kg body weight. However, it was not associated with average daily gain, backfat thickness and loin eye muscle area. Individuals with the genotype I/I had about 76.6 ± 27.1 g lower average daily feed intake, 5.35 ± 1.90 kg lower total feed intake and 0.089 8 ± 0.026 5 lower feed conversion ratio than individuals with I/II and II/II genotypes. Thus, AMY2B CNV has the potential to be an effective genetic marker that could reduce feed costs for pig farming.  


2020 ◽  
Vol 9 (8) ◽  
pp. e978986866
Author(s):  
Rafael Pereira Barros ◽  
Joaldo Rocha Luz ◽  
Ana Paula de Souza Ramos ◽  
Deise Silva Costa ◽  
Luís Gustavo Tavares Braga

The objective of this study was to determine the crude protein requirements for juvenile jundiara fish, a hybrid of Pseudoplatystoma fasciatum X Leiarius marmoratus. A total of 240 juveniles of the hybrid, with an initial mean weight of 8.4 ± 1.41 g, were distributed in 15 fiberglass tanks (170 L) in a closed water recirculation and constant aeration system, with a density of 16 fish/tank. The experimental design was completely randomized with five treatments and three replications. The treatments consisted of diets with 32, 34, 36, 38 and 40% crude protein. Seventy days into the experiment the final fish weight and feed intake were measured. Two specimens from each experimental unit were collected for evaluation of carcass chemical composition, nutritional efficiency and blood parameters. The increase in crude protein content promoted the significant, increasing linear effect for mean weight gain, mean feed intake and specific growth rate, and decreasing effect for feed conversion. Significant differences were also observed in carcass chemical composition, nutritional efficiency, total plasma protein, glucose, cholesterol, triglycerides and lipase enzymatic activity. Thus, the increase in crude protein levels of up to 40% in jundiara diets promotes improvement in the productive performance of juvenile jundiara.


2007 ◽  
Vol 2007 ◽  
pp. 85-85 ◽  
Author(s):  
H.L. Edge ◽  
K. Breuer ◽  
K. Hillman ◽  
C.A. Morgan ◽  
A. Stewart ◽  
...  

Weaning pigs from the sow at an older age, when their digestive systems are more mature, has been suggested as an approach to reduce the potentially negative effect of the in-feed antibiotic growth promoter (AGP) ban on the national pig herd. Whilst this approach has been shown to improve feed intake and piglet growth rate during the early postweaning period (Edge et al. 2006) it is also important to consider how changes in weaning age may influence sow productivity and longevity in the herd. The AGEWEAN programme of research followed 570 gilts whose piglets were weaned at either 4, 6 or 8 weeks of age through four successive parities; reproductive performance, litter data and the timing and reasons for any sow being culled from the herd were recorded.


2020 ◽  
Vol 12 (10) ◽  
pp. 3993
Author(s):  
Emilio Gómez Izquierdo ◽  
Luis Gomez-Raya ◽  
Eduardo de Mercado de la Peña ◽  
Juan José Ciruelos ◽  
Wendy M. Rauw

There is an interest in replacing soybean meal with locally produced ingredients in livestock feeds. Narbon vetch is resistant to unfavorable climatic and soil conditions, common pests, and has a favorable nutritional profile. The effect of substitution of soybean meal with 0% (V0), 5% (V5), 10% (V10), and 20% (V20) inclusion of Narbon vetch on growth curve parameters, daily body weight gain (DBWG), daily feed intake (DFI), feed conversion efficiency (FCE), and residual feed intake (RFI) was investigated in 47 Duroc × Iberian barrows in 16 periods (a total of 125 d). DFI and DBWG were reduced (p < 0.05) up to four weeks after introduction of the novel feed in V20 and V10. Small, mostly nonsignificant differences existed between treatments in FCE and RFI. However, because of accumulative small differences in feed efficiency between the four diets, pigs in V0 reached the highest BW, and pigs in V20 reached the lowest BW on a similar feed intake. Economic implications of Narbon vetch inclusion depend on the extra amount of feed required and associated feed costs, and on the costs of additional days on-farm required to reach a given slaughter weight.


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