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F H Benoff

Publications and source records attributed to F H Benoff.

12 recordsLinked to original sources
PubMed1990

Examination of the physical characteristics in a diverse group of dwarf White Leghorn pullets before and after first oviposition.

The purpose of the present experiment was to measure changes in physical variables with sexual maturity (SM), the oviposition of first egg, in sex-linked dwarf pullets when SM was delayed by the photoschedule. Offspring were produced from matings of dwarf Single Comb White Leghorn chickens divergently selected for high (H) or low (L) 20-wk BW. At 15 wk of age, pullets from half-sibling sets were randomly assigned to a diet either of low energy (LE: 2,500 kcal/kg of ME, 15% CP) or high energy (HE: 3,000 kcal/kg of ME, 15% CP) and were placed in cages. When a pullet reached SM, the mature (M) pullet and an immature (I, absence of oviposition), half-sibling pullet on the same diet were sampled for BW as well as for the weights of abdominal fat, liver, ovary, oviduct, whole egg (M pullets), yolk, and shell and for the number of rapidly developing follicles. Proximate measurements (wet weight) were made for defeathered carcasses and livers as well as for ovaries and oviducts. There were significant (P less than or equal to .01) line effects for BW at SM (H greater than L); age at SM (L greater than H); weights for the liver, abdominal fat, egg, albumen, shell (H greater than L), and yolk (L greater than H); number of developing follicles (H greater than L); percentage of carcass protein (L greater than H) and of fat (H greater than L); as well as for liver protein (L greater than H), fat (H greater than L), and ash (L greater than H). There were significant (P less than .01) diet effects for abdominal fat (HE greater than LE) and shell weight (LE greater than HE). There was a line-by-diet interaction for total feed intake and for total energy intake from 15 wk to oviposition of the first egg. There were significant (P less than .01) SM effects (M greater than I) for BW at SM, number of developing follicles, oviduct weight, and fat content of the reproductive organs; also, reproductive organ weights accounted for differences in BW at SM. There was an interaction for line by maturity state; the L pullets showed a greater increase in ovarian weight with oviposition of the first egg than did the H pullets. The results of this study indicated that the threshold requirements for BW, composition, or both, for SM may have been exceeded in Leghorn-type chickens when photoscheduling was used to delay the onset of SM.

Abdomen↗
PubMed1986

Nutritive value of poultry by-product meal. 1. Metabolizable energy values as influenced by method of determination and level of substitution.

Experiments were conducted to determine the metabolizable energy (MEn) of eight poultry by-product meal (PBPM) samples. Samples averaged 5.44% moisture, 4.84 kcal gross energy (GE)/g dry matter (DM), 61.2% crude protein, 13.38% ether extract, 16.1% ash, 5.14% calcium, and 2.36% phosphorus. Samples of PBPM were substituted in the diet at levels of 20 and 40%. Values of ME were calculated with substitution for the diet (Matterson's method) and for glucose (Hill's method) and by the fasted cockerel method. Values of PBPM MEn were 7.9% greater when substitution was for diet as compared with substitution for glucose; values were 2.95 and 2.74 kcal/g DM, respectively. Using Matterson's method with three samples, MEn values were determined to be 12.1% greater when PBPM was substituted at the rate of 20% than at 40%; values were 3.33 and 2.97 kcal/g DM, respectively. Differences in MEn between the best and poorest samples (3.79 and 2.77 kcal/g DM) could be attributed to differences in gross energy (5.00 and 4.49 kcal/g DM) and percentage of gross energy metabolized (75.7 and 61.7%). Metabolizable energy was more closely related to body weight gains than the amount of feed consumed. When a modification of Sibbald's fasted cockerel technique was used, true MEn of the eight samples averaged 3.35 kcal/g DM and 69% of GE metabolized. For the three samples assayed by both methods, Matterson's method gave values averaging .97% higher than Sibbald's (+4.3, +.8, and -2.2%). Differences in MEn were mostly highly correlated with ash (-.89), calcium (-.85), and GE (.78) contents of the diets. Projections from relationships found between ME and nutrient compositions of these samples to the average sample used by the poultry industry in the Southeast indicate an average of 3.57 kcal ME/g DM of PBPM (3.39 kcal/g as is).

Animal Feed↗
PubMed1983

Testosterone aromatization in high and low mating lines of gallinaceous birds.

Capons from high (HML) and low (LML) mating lines of Japanese quail and chickens received testosterone propionate, 5 alpha-dihydrotestosterone (5 alpha-DHT) or estradiol benzoate injections after which copulatory behavior was observed during exposure to live females and to a female model. With live females, the testosterone-treated HML capons mated significantly more than the other HML groups. All LML capons mated infrequently and at comparable levels. When tested with the model, estrogen-treated LML capons mated significantly more frequently than testosterone-treated LML capons, suggesting testosterone aromatization rate was affecting mating activity. This possibility was tested with HLM and LML intact cocks and capons receiving silastic implants of either testosterone, 5 alpha-DHT or a combination of estradiol and 5 alpha-DHT (E + DHT). Mating activity of intact HML cocks, T-treated, and E + DHT-treated HML capons were similar, and all groups mated significantly more than the control or 5 alpha-DHT-treated capons. There were no significant differences between any of the LML groups. The data suggested that limited testosterone aromatization was not the cause of relatively reduced sexual activity in the LML males.

Animals↗
PubMed1983

Effects of the sex-linked dwarfing gene (dw) on growth and reproduction in white Leghorn hens.

The influence of the dwarfing gene, dw, on growth and reproduction was determined by comparing 1) pure line and reciprocal cross dwarf and normal layers and 2) dwarf and normal full-sib sisters. In Experiment 1, two lines of chickens, the Oregon State University randombred dwarf Leghorn population (D) and Shaver Starcross "288" Leghorns (S), were mated within line and reciprocally to produce normal-sized (SS, SD) and dwarf (DS, DD) female progeny. All progeny were reared similarly until 18 weeks of age when birds were transferred to individual cages. At 18 weeks of age, half the pullets were fed a basal laying ration containing 15% protein while the remaining birds received the basal ration with .1% supplemental methionine. In Experiment 2, full-sib normal and dwarf sisters were obtained by mating hemizygous dwarf females to heterozygous males. Layers were reared in a similar manner to those in Experiment 1 with the exception that all layers received the basal ration with .1% methionine supplemented. Methionine supplementation in Experiment 1 significantly increased egg weights at 35 and 62 weeks of age for all lines and crosses but had no effect on other growth and reproductive traits. Genotype X diet interactions were not observed for any of the measured traits. Normal-sized layers had significantly heavier body weights and longer shank lengths than dwarf layers in both experiments. Dwarf hens in both experiments showed reduced egg production capabilities, although ages at sexual maturity were similar among phenotypes. Dwarf layers laid smaller eggs than normal-sized layers. There were no consistent differences in feed efficiency measures between normals and dwarfs.

Animals↗
PubMed1983

Divergent selection for mature body weight in dwarf White Leghorns. 1. Growth and reproductive responses to selection.

Genetic selection for high (H) and low (L) 20-week body weight (BW) in dwarf White Leghorns was practiced for three generations. The base population was the Oregon State University dwarf Leghorn population (C) selected previously for part year hen-housed egg production (EP), early sexual maturity (SM), and large initial egg weight (EW). Asymmetry of response was observed in both sexes. Realized heritabilities for 20-week BW for H and L males were .49 and .36 and for H and L females were .45 and .79, respectively. Twenty-week BW of the 3rd generation H and L line females were 1.48 and .80 kg, respectively, compared to 1.13 kg for the C line. Similar weights for the males were 1.74, .97, and 1.27 kg for the H, L, and C line, respectively. The H and L lines diverged significantly in 10, 20, 40, and 60-week BW, SM, and EW after one generation of selection and the divergence continued through the third generation. The EP and egg specific gravity did not differ among lines. The C line was intermediate to the selected lines for all traits except EP. The EW at 35 and 60 weeks differed between the H and L lines by 10 g at generation 3 and SM was 149 and 157 days for the H and L lines, respectively.

Animals↗
PubMed1981

Histochemistry of uterovaginal sperm-host glands in Japanese Quail (Coturnix coturnix japonica) with reference to the period of oviposition.

General histochemistry of uterovaginal sperm-host glands (SHG) of Japanese quail was examined in virgin and naturally mated hens and during oviposition in artificially inseminated hens. The SHG tissues were stained for complex carbohydrates with periodic acid - Schiff (PAS); for lipids with oil red O (ORO); and for acid phosphatase (AP) with AS-TR phosphate substrate. Typically, PAS material was absent from SHG cells, SHG showed preferential uptake of ORO, and the stain was seen as discrete droplets with greater accumulation in the apical and basal portions of the epithelia. The SHG showed reduced ORO with an egg in the uterus, and staining was not altered by presence or absence of sperm. All epithelia of the uterovaginal region showed strong AP activity with greatest concentration in the apical portion of the SHG epithelia.

Acid Phosphatase↗
PubMed1980

Effects of progesterone on developing chick embryos.

Experiments were conducted to examine the effects of progesterone on the developing chick embryo with particular attention to the reproductive system. Differing levels of progesterone (0, .5, 1.0, or 2.0 mg) were dissolved in propylene glycol and injected at 4 days of incubation into the yolk sac of eggs from Barred Plymouth Rock females mated to New Hampshire males. Progesterone caused significant reductions in both weight and length and shank weight and length in 18-day-old embryos. Aside from reductions in embryonic growth, progesterone did not cause gross alterations in embryonic development. Progesterone modified neither normal morphology nor differentiation of male or female gonads and associated ductal systems.

Animals↗
PubMed1978

The effect of oviposition on fertility in chickens.

The fertility between the first two eggs of a clutch and between eggs oviposited by the same bird on the same day were compared to determine the effect of oviposition on fertility. No differences in fertility were observed indicating that factors other than oviposition are involved in the mechanism of spermatozoal release and fertility in chickens.

Animals↗